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http://www.zora.uzh.ch/16578/
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Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-16578
# Mandelbaum, R; Seljak, U; Hirata, C M (2008). A halo mass—concentration relation from weak lensing. Journal of Cosmology and Astroparticle Physics, 2008(8):006.
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## Abstract
We perform a statistical weak lensing analysis of dark matter profiles around tracers of halo mass from galactic- to cluster-size halos. In this analysis we use 170 640 isolated ∼ L∗ galaxies split into ellipticals and spirals, 38 236 groups traced by isolated spectroscopic Luminous Red Galaxies (LRGs) and 13 823 MaxBCG clusters from the Sloan Digital Sky Survey (SDSS) covering a wide range of richness. Together these three samples allow a determination of the density profiles of dark
matter halos over three orders of magnitude in mass, from 1012M⊙ to 1015M⊙. The resulting lensing signal is consistent with an NFW or Einasto profile on scales outside the central region. In the inner regions, uncertainty in modeling of the proper identification of the halo center and inclusion of baryonic effects from the central galaxy make the comparison less reliable. We find that the NFW concentration parameter c200b decreases with halo mass, from around 10 for galactic halos to 4 for cluster halos. Assuming its dependence on halo mass in the form of c200b = c0(M/1014h−1M⊙)− we find c0 = 4.6 ± 0.7 (at z = 0.22) and = 0.13 ± 0.07, with very similar results for the Einasto profile. The slope () is in agreement with theoretical predictions, while the amplitude is about two standard deviations below the predictions for this mass and redshift, but we note that the published values in the literature differ at a level of 10-20% and that for a proper comparison our analysis should be repeated in simulations. We compare our results to other recent determinations, some of which find significantly higher concentrations. We discuss the implications of our results for the baryonic effects on the shear power spectrum: since these are expected to increase the halo concentration, the fact that we see no evidence of high concentrations on scales above 20% of the virial radius suggests that baryonic effects are limited to small scales, and are not a significant source of uncertainty for the current weak lensing measurements of the dark matter power spectrum.
## Citations
105 citations in Web of Science®
89 citations in Scopus®
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## Downloads
71 downloads since deposited on 13 Mar 2009
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## Additional indexing
Item Type: Journal Article, refereed, original work 07 Faculty of Science > Institute for Computational Science 530 Physics English August 2008 13 Mar 2009 11:46 27 Nov 2013 16:46 Institute of Physics Publishing 1475-7516 10.1088/1475-7516/2008/08/006 http://arxiv.org/abs/0805.2552v2
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http://hitchhikersgui.de/Net_tonnage
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# Net tonnage
Net tonnage is calculated by measuring a ship's internal volume and applying mathematical formulae.
Net tonnage (often abbreviated as NT, N.T. or nt) is a dimensionless index calculated from the total moulded volume of the ship's cargo spaces by using a mathematical formula. Defined in The International Convention on Tonnage Measurement of Ships that was adopted by the International Maritime Organization in 1969, the net tonnage replaced the earlier net register tonnage (NRT) which denoted the volume of the ship's revenue-earning spaces in "register tons", units of volume equal to 100 cubic feet (2.83 m3).[1] Net tonnage is used to calculate the port duties and should not be taken as less than 30 per cent of the ship's gross tonnage.[2]
Net tonnage is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement. Also, unlike the net register tonnage, the net tonnage is unitless and thus can not be defined as "tons" or "net tons".
## History
The International Convention on Tonnage Measurement of Ships, 1969 was adopted by IMO in 1969.[3] Ships built before that date were given 12 years to migrate from their existing tonnage to use of NT and GT.[3] The phase-in period was provided to allow ships time to adjust economically, since tonnage is the basis for satisfying manning regulations and safety rules.[3] Tonnage is also the basis for calculating registration fees and port dues.[3] One of the Convention's goals was to ensure that the new units "did not differ too greatly" from the traditional GRT and NRT units.[3]
Both NT and GT are obtained by measuring ship's volume and then applying a mathematical formula.[3] Net tonnage is based on "the moulded volume of all cargo spaces of the ship" while gross tonnage is based on "the moulded volume of all enclosed spaces of the ship".[3] In addition, a ship's net tonnage is constrained to be no less than 30% of her gross tonnage.[3]
## Calculation
### Choice of draft value
The net tonnage calculation is based on a number of factors, one of which is the moulded draft d. The choice of the value to use for d can be complicated. For ships subject to the International Convention on Load Lines, the Summer Load Line draft is used, with the exception of cases where that is a timber load line. For passenger ships, the draft used is the deepest subdivision load line assigned in accordance with the International Convention for the Safety of Life at Sea. Otherwise, if a ship has been assigned a load line by its national government, the draft for that summer load line is used. If the ship has no load line, instead, a maximum draft assigned by its national government, that value is used, if it has been assigned a maximum. Finally, for a ship to which none of the above applies, the value of d is taken as 75 per cent of the moulded depth amidships.
### 12 or fewer passengers
The Net tonnage calculation is defined in Regulation 4 of Annex 1 of The International Convention on Tonnage Measurement of Ships, 1969. It is based on two main variables:
• Vc, the total volume of the ship's cargo spaces in cubic meters (m³),
• d, the ship's moulded draft amidships in meters, and
• D, the ship's moulded depth amidships in metres
The first step in calculating NT is to find the value known as K2, a multiplier based on Vc. It is obtained by using the following formula:
${\displaystyle K_{2}=0.2+0.02\times \log _{10}(V_{c})}$
And then these three values are used to calculate NT using this formula:
${\displaystyle NT=K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}}$
Where the factor ${\displaystyle ({\tfrac {4d}{3D}})^{2}}$ will not exceed 1, the term ${\displaystyle K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}}$ will not be less than 0.25 GT, and the final value of NT shall not be taken as less than 0.30 GT.
### 13 or more passengers
When calculating NT for ships certified to carry 13 or more passengers, an additional term is used in the NT formula. It is based on three additional variables:
• GT, the ship's gross tonnage,
• N1, number of passengers in cabins with not more than 8 berths, and
• N2, number of other passengers,
First, a multiplier K3, based on the ship's gross tonnage is found,
${\displaystyle K_{3}={\frac {1.25\times (GT+10000)}{10000}}}$
Then the net tonnage is calculated:
${\displaystyle NT=K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}+K_{3}\times (N_{1}+{\frac {N_{2}}{10}})}$
Where the factor ${\displaystyle ({\tfrac {4d}{3D}})^{2}}$ shall not be taken as greater than unity, the term ${\displaystyle K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}}$ will not be less than 0.25 GT, and the final value of NT shall not be taken as less than 0.30 GT.
The difference between the cases of 12 of fewer passengers and 13 or more passengers is due to a restriction given in the net tonnage definition that states "...when N1 + N2 is less than 13, N1 and N2 shall be taken as zero."
## Usage
In the United States, net tonnage is used to determine eligibility for registering boats with the federal government. Vessels with net tonnage of five or more are eligible for federal registration and not required to display state registration numbers. Most vessels longer than 25 feet are five tons or more.[4]
## Notes
1. ^ Stopford, Martin (2009), Maritime Economics, Taylor & Francis, p. 752, retrieved 2011-10-17
2. ^ International Convention on Tonnage Measurement of Ships. International Maritime Organization (IMO). Retrieved 2011-10-17.
3. International Maritime Organization, 1982.
4. ^ "USCG National Vessel Documentation Center, FAQ Page". uscg.mil. 2011. Retrieved 7 May 2011.
## References
• "International Convention on Tonnage Measurement of Ships, 1969". 1969-06-23. Retrieved 2008-03-23.
• International Maritime Organization (2002). "International Convention on Tonnage Measurement of Ships, 1969". International Maritime Organization. Archived from the original on 2009-07-07. Retrieved 2008-03-23.
• Hayler, William B. (2003). American Merchant Seaman's Manual. Cornell Maritime Press. ISBN 0-87033-549-9..
• Singh, Baljit (July 11, 1999). "The world's biggest ship". The Times (of India). Retrieved 2008-04-07.
• Turpin, Edward A.; McEwen, William A. (1980). Merchant Marine Officers' Handbook (4th ed.). Centreville, MD: Cornell Maritime Press. ISBN 0-87033-056-X.
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https://www.gradesaver.com/textbooks/math/applied-mathematics/elementary-technical-mathematics/chapter-1-section-1-2-order-of-operations-exercise-page-14/42
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## Elementary Technical Mathematics
Published by Brooks Cole
# Chapter 1 - Section 1.2 - Order of Operations - Exercise: 42
288
#### Work Step by Step
= 3(10+2(1+3(2+6(4-2)))) Do the operations from the innermost to outermost parentheses = 3(10+2(1+3(2+6(2)))) Multiply = 3(10+2(1+3(2+12))) Add = 3(10+2(1+3(14))) Multiply = 3(10+2(1+42)) Add = 3(10+2(43)) Multiply = 3(10+86) Add = 3(96) Multiply = 288
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.
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https://www.physicsforums.com/threads/cocktail-recipes.739801/
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# Cocktail Recipes!
1. Feb 22, 2014
### lisab
Staff Emeritus
I recently have started to appreciate a good cocktail!
I'm a "beginner", so I don't know much more than the basic ones (screwdriver, martini, rum and coke (which is atrocious!), tequila sunrise, etc.).
My step-son introduced me to this one, it's very nice. It's a "Last Word".
Equal parts:
Gin
Chartreuse
Maraschino liqueur
Fresh lime juice
Shake with ice, serve with no ice.
Be forewarned, it's pretty strong. And expensive (Chartreuse in the US is :surprised\$!).
The common ones mentioned above are OK (except the rum and coke :yuck:), but do you like any that are not commonly known?
2. Feb 22, 2014
Staff Emeritus
Green or yellow Chartreuse?
(And it's not cheap anywhere. )
3. Feb 22, 2014
### lisab
Staff Emeritus
Green. Have you had yellow? It's not available in my little town.
4. Feb 22, 2014
### Greg Bernhardt
Lisa that sounds amazing! I'll have to try it out! My staple summer drink is a Moscow mule and a White Russian for winter. Hmmm just realized the link between the two lol :D
5. Feb 22, 2014
### Staff: Mentor
Oh, chartruese. We called it swamp water. I won't buy it. Nasty stuff!!!
6. Feb 22, 2014
### Greg Bernhardt
I enjoy it. Even taking it as a shot.
7. Feb 22, 2014
### turbo
Lisab, this isn't really a cocktail, but if you will buy a pint of decent bourbon you can try this. Get out a tall water glass, and put in 3-4 ice cubes. Splash a little bourbon over the ice, leaving 1/4" or less in the bottom of the glass, then top it off with water. Once you have a feel for the proportions, you can adjust. It's a great way to enjoy bourbon, IMO.
I hate drinking anything sweet or heavy, and this is my go-to.
8. Feb 23, 2014
### Staff: Mentor
Does that qualify as a cocktail? It's just bourbon and water.
9. Feb 23, 2014
### turbo
I said that at the top of my post. Did you read it?
10. Feb 23, 2014
### Staff: Mentor
Then why post it in a cocktail thread?
11. Feb 23, 2014
### Staff: Mentor
The only cocktail I care for is a dirty martini. But I also like black martinis.
Dirty martini
2 1/2 ounces gin
1/2 ounce dry vermouth (I prefer to skip the vermouth)
1/4-1/2 ounce olive juice, to taste
Olive for garnish
Black martini
Ingredients:
3 ounces gin or vodka
1/2 ounce blackberry brandy or black raspberry liqueur
Lemon twist for garnish
Oh, but frozen peach bellinis!!!
Ingredients:
2 ounces peach juice or peach puree
4 ounces Champagne
12. Feb 23, 2014
### turbo
Because if someone is transitioning from wine, beer, etc, it might be nice to give some guidance. Just trying to be helpful.
13. Feb 23, 2014
### Staff: Mentor
OK, but it's just adding water, like adding ice... It's not a cocktail.
14. Feb 23, 2014
### lisab
Staff Emeritus
I don't like drinks that are too sweet, btw. Orange or apple juice is about as sweet as I can stand.
I might make an exception at a swim-up bar, on a pristine sunny day, in a tropical location, if the drink is served in a pineapple with an umbrella .
15. Feb 23, 2014
### Staff: Mentor
I'm the same, too sweet froo froo cocktails are not for me. Have you had a bellini? Those are really good. A perfect summer drink.
16. Feb 23, 2014
### lisab
Staff Emeritus
I haven't, but as peaches come available I definitely will. I think it wouldn't be the same with canned peaches :uhh:.
17. Feb 23, 2014
Staff Emeritus
Yes, in Grenoble, not far from where they make it. It's..um...different.
18. Feb 23, 2014
### lisab
Staff Emeritus
I like the green. It, too, is...different. A bit sweet but I like the spiciness. There's a lot going on there, I can't quite grasp what I'm tasting. I can understand why it invokes memories of cough syrup in some people though.
19. Feb 24, 2014
### Danger
Chartreuse would gag a maggot. In the bar that I worked at, we had the same bottle on the shelf for 15 years. The only time that it was ordered, the woman spit it out on the floor rather than swallow it.
Our signature Canuck cocktail was invented here in Calgary. The proper name is "Bloody Caesar", but it's just called a Caesar. It is made with vodka on the rocks and clamato juice, seasoned with Worstershire and Tobasco sauces, with a salted or celery-salted rim and a celery stalk, asparagus spear, or spiced bean pod as garnish, with a lime wedge clamped onto the rim. It's the only vegetable that I'll consume.
By the bye, the term "cocktail" came from the garnish of coloured feathers that were used in fancy drinks in days of yore. Things like rye and Dry or bourbon (:yuck:) and water are just highballs.
Last edited: Feb 24, 2014
20. Feb 24, 2014
### Staff: Mentor
Absolutely agree!
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http://www.thermix.net/2012/08/the-separating-and-throttling.html
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## THE SEPARATING AND THROTTLING CALORIMETER BASIC INFORMATION AND TUTORIALS
The quality (i.e. the dryness) of wet steam can be found by using a separating and throttling calorimeter. Figure 2.6.4 shows the general arrangement of the device.
The separator, as its name suggests, physically separates the water droplets from the steam sample. This alone would give us a good idea of the dryness of the steam, despite that the separation is not complete, because, as we have seen the dryness fraction is the ratio of the mass of pure steam to the total mass of the steam.
Having separated out the water droplets we can find their mass to give us the mass of water in the sample, m1. The ‘pure steam’ is then condensed to allow its mass to be found, m2. Then,
Dryness fraction from separator, x = m2/ (m1 + m2)
A more accurate answer is obtained by connecting the outlet from the separator directly to a throttle and finding the dryness fraction of the partly dried steam.
In the throttling calorimeter, the steam issuing through the orifice must be superheated, or we have two dryness fractions, neither of which we can find. Throttling improves the quality of the steam, which is already high after passing through the separator, therefore superheated steam at this point is not difficult to create.
To find the enthalpy of the superheated steam, we need its temperature and its pressure.
For the throttling calorimeter,
Enthalpy before = enthalpy after throttling
hf + x.hfg = enthalpy from superheat tables
If we call the dryness from the separator, x1, and the dryness from the throttling calorimeter x2, the dryness fraction of the steam sample is x, given by, x = x1 × x2
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http://mathoverflow.net/questions/124153/can-random-elements-be-defined-in-terms-of-a-measure-algebra
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# Can random elements be defined in terms of a measure algebra?
Let $(\Omega,\Sigma,\mu)$ be a probability space, $(X,\mathcal{X})$ be a measurable space and $R(\Omega,X)$ be the set of equivalence classes of measurable functions from $\Omega$ to $X$ under almost everywhere equality, they are random elements. Let $(\mathcal{A},\mu_A)$ be the measure algebra of $(\Omega,\Sigma,\mu)$, that is $\mathcal{A}$ identifies elements of $\Sigma$ if their symmetric difference has outer measure zero and $\mu_A$ is defined in the natural way in terms of its representatives.
I would like to know if one can identify the elements of $R(\Omega,X)$ with something that can be canonically be constructed in terms of $(\mathcal{A},\mu_A)$ and $(X,\mathcal{X})$.
The motivation behind the question is the following: I work with certain random elements that are defined on a countably generated probability space. By Maharam's theorem, this amounts to the measure algebra being isomorphic to one that consists of a convex combination of Lebesgue measure on $[0,1]$ and a discrete probability space. I would like to know whether it makes sense for me to say that I'm essentially working with such a probability space.
-
Perhaps this calls for consideration of the Image measure catastrophe ... google.com/search?as_q=&as_epq=image+measure+catastrophe – Gerald Edgar Mar 10 '13 at 16:27
@Gerald: could you please summarize the image measure catastrophe in a comment? – Tom LaGatta Mar 11 '13 at 0:34
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https://math.stackexchange.com/questions/2032311/finding-equivalence-class-with-a-binary-set
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# Finding equivalence class with a binary set
I'm new to discrete math so there might be problems with this solution. Prompt is to find at least one equivalence class if it is an equivalence relation.
$$X = R^2, (x_1, y_1) \sim (x_2, y_2) \iff y_1 = y_2$$
1. Reflexivity
$$(x_1, y_1) \sim (x_1, y_1) \iff y_1 = y_1$$
Since $y_1 = y_1$, it is reflexive.
2. Symmetry
$$(x_1, y_1) \sim (x_2, y_2) \iff y_1 = y_2$$
Assuming $y_1 = y_2$ (eqn1),
$$(x_2, y_2) \sim (x_1, y_1) \iff y_2 = y_1$$
from eqn 1, $y_2 = y_1$, so it is a symmetry.
3. Transitivity
$$(x_1, y_1) \sim (x_2, y_2) \iff y_1 = y_2$$
$$(x_2, y_2) \sim (x_3, y_3) \iff y_2 = y_2$$
Assuming $y_1 = y_2$ and $y_2 = y_3$, we get $y_1 = y_3$.
$$(x_1, y_1) \sim (x_3, y_3) \iff y_1 = y_3,$$
since $y_1 = y_3$, so it is transitive.
Is this the correct way to solve the problem? Also how to find the equivalence classes for the same?
You did correctly. Well.. to find the equivalent class, you often need a representant of that class. Take $(x, y)$, and we want $[(x, y)]$ to be an equivalent class which contains the element $(x, y)$. In other words, $(x, y)$ represents that class. That is: $$[(x, y)] = \{(a, b)\in\mathbb{R}^2 : (x, y)\sim(a, b)\}$$
We have an equivalent class such that $(x, y)\in [(x, y)]$. Now, its all a matter of inserting the definition of $\sim$ in the set. $$[(x, y)] = \{(a, b)\in\mathbb{R}^2 : y=b\}$$
Can you come up with a concrete example? What would $[(1, 2)]$ be, for instance?
Yes, your proof is correct. To construct an equivalence class, pick an element of the set and find (describe) all elements that are equivalent to it. More formally: if $R$ is an equivalence relation on a set $X$, then for an $x\in X$, its equivalence class is $[x]=\{y\in X\,\colon\,yRx\}$. In this example: pick an arbitrary $(x,y)\in\mathbb{R}^2$. By the given definition, any other $(x_1,y_1)\in\mathbb{R}^2$ is equivalent to it, $(x_1,y_1)\sim(x,y)$, iff $y_1=y$, so $(x_1,y_1)=(x_1,y)$. Note that there are no constraints on $x_1$, so it can be any real. Thus the equivalence class of $(x,y)$ is $\{(x_1,y)\in\mathbb{R}^2\,\colon\,x_1\in\mathbb{R}\}$ (where $y$ is fixed). Geometrically, they are horizontal lines $y=\text{const}$.
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https://ch.mathworks.com/help/econ/tune-mcmc-sample-for-posterior-estimation.html
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Tune Slice Sampler For Posterior Estimation
This example shows how to improve the slice sampler for posterior estimation and inference of a Bayesian linear regression model.
When estimating the posterior composed of the data likelihood and semiconjugate or custom prior models, estimate uses an MCMC sampler. If a trace plot of the sample shows transient behavior or very high serial correlation, or you want to store few samples from the posterior, then you can specify a burn-in sample or thinning.
Consider the multiple linear regression model that predicts the US real gross national product (GNPR) using a linear combination of industrial production index (IPI), total employment (E), and real wages (WR).
For all time points, is a series of independent Gaussian disturbances with a mean of 0 and variance . Assume that the prior distributions are:
• is 4-dimensional t distribution with 50 degrees of freedom for each component and the identity matrix for the correlation matrix. Also, the distribution is centered at and each component is scaled by the corresponding elements of the vector .
• .
bayeslm treats these assumptions and the data likelihood as if the corresponding posterior is analytically intractable.
Declare a MATLAB® function that:
• Accepts values of and together in a column vector, and values of the hyperparameters.
• Returns the value of the joint prior distribution, , given the values of and .
function logPDF = priorMVTIG(params,ct,st,dof,C,a,b) %priorMVTIG Log density of multivariate t times inverse gamma % priorMVTIG passes params(1:end-1) to the multivariate t density % function with dof degrees of freedom for each component and positive % definite correlation matrix C. priorMVTIG returns the log of the product of % the two evaluated densities. % % params: Parameter values at which the densities are evaluated, an % m-by-1 numeric vector. % % ct: Multivariate t distribution component centers, an (m-1)-by-1 % numeric vector. Elements correspond to the first m-1 elements % of params. % % st: Multivariate t distribution component scales, an (m-1)-by-1 % numeric (m-1)-by-1 numeric vector. Elements correspond to the % first m-1 elements of params. % % dof: Degrees of freedom for the multivariate t distribution, a % numeric scalar or (m-1)-by-1 numeric vector. priorMVTIG expands % scalars such that dof = dof*ones(m-1,1). Elements of dof % correspond to the elements of params(1:end-1). % % C: Correlation matrix for the multivariate t distribution, an % (m-1)-by-(m-1) symmetric, positive definite matrix. Rows and % columns correspond to the elements of params(1:end-1). % % a: Inverse gamma shape parameter, a positive numeric scalar. % % b: Inverse gamma scale parameter, a positive scalar. % beta = params(1:(end-1)); sigma2 = params(end); tVal = (beta - ct)./st; mvtDensity = mvtpdf(tVal,C,dof); igDensity = sigma2^(-a-1)*exp(-1/(sigma2*b))/(gamma(a)*b^a); logPDF = log(mvtDensity*igDensity); end
Create an anonymous function that operates like priorMVTIG, but accepts only the parameter values, and holds the hyperparameter values fixed at their values.
dof = 50; C = eye(4); ct = zeros(4,1); st = ones(4,1); a = 3; b = 1; logPDF = @(params)priorMVTIG(params,ct,st,dof,C,a,b);
Create a custom joint prior model for the linear regression parameters. Specify the number of predictors, p. Also, specify the function handle for priorMVTIG and the variable names.
p = 3; PriorMdl = bayeslm(p,'ModelType','custom','LogPDF',logPDF,... 'VarNames',["IPI" "E" "WR"]);
PriorMdl is a customblm Bayesian linear regression model object representing the prior distribution of the regression coefficients and disturbance variance.
Load the Nelson-Plosser data set. Create variables for the response and predictor series.
load Data_NelsonPlosser X = DataTable{:,PriorMdl.VarNames(2:end)}; y = DataTable{:,'GNPR'};
Estimate the marginal posterior distributions of and . To determine an appropriate burn-in period, specify no burn-in period. Specify a width for the slice sampler that is close to the posterior standard deviation of the parameters assuming a diffuse prior model. Draw 15000 samples.
width = [20,0.5,0.01,1,20]; numDraws = 15e3; rng(1) % For reproducibility PosteriorMdl1 = estimate(PriorMdl,X,y,'BurnIn',0,'Width',width,... 'NumDraws',numDraws);
Warning: High autocorrelation of MCMC draws:IPI,E,WR,Sigma2. Method: MCMC sampling with 15000 draws Number of observations: 62 Number of predictors: 4 | Mean Std CI95 Positive Distribution ----------------------------------------------------------------------- Intercept | -0.6669 1.5325 [-3.202, 1.621] 0.309 Empirical IPI | 4.6196 0.1021 [ 4.437, 4.839] 1.000 Empirical E | 0.0004 0.0002 [ 0.000, 0.001] 0.995 Empirical WR | 2.6135 0.3025 [ 1.982, 3.152] 1.000 Empirical Sigma2 | 48.9990 9.1926 [33.147, 67.993] 1.000 Empirical
PosteriorMdl1 is an empiricalblm model object. The BetaDraws and Sigma2Draws properties store the samples from the slice sampler.
Draw trace and autocorrelation plots for the Markov chains.
figure; for j = 1:4 subplot(2,3,j) plot(PosteriorMdl1.BetaDraws(j,:)); axis tight xlabel('Sample index') title(sprintf(['Trace Plot ' char(8212) ' %s'],PriorMdl.VarNames{j})); end subplot(2,3,5) plot(PosteriorMdl1.Sigma2Draws); axis tight xlabel('Sample index') title(['Trace Plot ' char(8212) ' Sigma2']); figure; for j = 1:4 subplot(2,3,j) autocorr(PosteriorMdl1.BetaDraws(j,:)); axis tight title(sprintf(['Correlogram ' char(8212) ' %s'],PriorMdl.VarNames{j})); end subplot(2,3,5) autocorr(PosteriorMdl1.Sigma2Draws); axis tight title(['Correlogram ' char(8212) ' Sigma2']);
All parameters, except the intercept, show significant transient effects and high autocorrelation. estimate checks for high correlation, and, if present, issues warnings. Also, the parameters do not seem to have converged to their stationary distribution.
Estimate the posterior distribution again. To reduce transient effects, use the default burn-in period (5000, which is the default). To reduce the affects of serial correlation, thin by a factor of 20 and specify 15e4/thin effective number of draws. Also, numerically stabilize the estimation of by specifying reparameterize to . Plot trace and autocorrelation plots.
thin = 20; numDraws = 15e4/thin; PosteriorMdl2 = estimate(PriorMdl,X,y,'Thin',thin,'Width',width,... 'Reparameterize',true,'NumDraws',numDraws); figure; for j = 1:4 subplot(2,3,j) plot(PosteriorMdl2.BetaDraws(j,:)); axis tight xlabel('Sample index') title(sprintf(['Trace Plot ' char(8212) '%s'],PriorMdl.VarNames{j})); end subplot(2,3,5) plot(PosteriorMdl2.Sigma2Draws); axis tight xlabel('Sample index') title(['Trace Plot ' char(8212) ' Sigma2']); figure; for j = 1:4 subplot(2,3,j) autocorr(PosteriorMdl2.BetaDraws(j,:)); title(sprintf(['Correlogram ' char(8212) ' %s'],PriorMdl.VarNames{j})); end subplot(2,3,5) autocorr(PosteriorMdl2.Sigma2Draws); title(['Correlogram ' char(8212) ' Sigma2']);
Method: MCMC sampling with 7500 draws Number of observations: 62 Number of predictors: 4 | Mean Std CI95 Positive Distribution ----------------------------------------------------------------------- Intercept | -0.4777 1.2225 [-2.911, 1.955] 0.338 Empirical IPI | 4.6506 0.1128 [ 4.434, 4.884] 1.000 Empirical E | 0.0005 0.0002 [ 0.000, 0.001] 0.991 Empirical WR | 2.5243 0.3468 [ 1.815, 3.208] 1.000 Empirical Sigma2 | 51.3444 9.3170 [36.319, 72.469] 1.000 Empirical
The trace plots suggest that the Markov chains:
• Have reached their stationary distributions because the distribution of the samples have a relatively constant mean and variance. Specifically, the distribution of the points does not seem to change.
• Are mixing fairly quickly because the serial correlation is moderate, for some parameters, to very low.
• Do not show any transient behavior.
These results suggest that you can proceed with a sensitivity analysis, or with posterior inference.
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https://wiki.kidzsearch.com/wiki/Grand_Canyon
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kidzsearch.com > wiki Explore:web images videos games
# Grand Canyon
The Grand Canyon
Another view of the Grand Canyon
The Grand Canyon is a famous canyon in Arizona, formed by the Colorado River. It is a UNESCO World Heritage Site,[1] and a National Park of the United States. It is also one of the Seven Natural Wonders of the World.
The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and is over a mile (1.83 km) (6000 feet) deep in places.[2] Nearly two billion years past of the Earth's geological history have been exposed as the Colorado River and its tributaries (smaller rivers) cut their channels through layer after layer of rock.[3]
Evidence suggests the Colorado River established its course through the canyon at least 17 million years ago.[4][5][6] Since that time, the Colorado River continued to erode and form the canyon to the point we see it at today.
"Local erosion in the western Grand Canyon began about 17 million years ago, but a through-flowing Colorado River to the Pacific Ocean did not exist until about 5.4 million years ago... most of the downward cutting has been concentrated in the last 2.5 million years".[7]
## Geology
Diagram showing the placement, age and thickness of the rock units exposed in the Grand Canyon.
The result of all the erosion is one of the most complete geologic columns (stacks of rock layers) on the planet. There are nearly 40 major sedimentary rock layers exposed in the Grand Canyon and in the Grand Canyon National Park area. They range in age from about 200 million to nearly 2 billion years old.
Most were laid down in warm, shallow seas, near ancient, long-gone sea shores in western North America. Both marine and terrestrial sediments are represented, including fossilized sand dunes from an ancient desert. There are at least 14 known unconformities in the geologic record found in the Grand Canyon area.
The major rock exposures in the Grand Canyon range in age from the almost 2 billion year old Vishnu Schist at the bottom of the Inner Gorge to the 230 million year old Kaibab Limestone on the rim.
Shown in the diagram, there is a gap of about one billion years between the stratum that is about 500 million years old (blue) and the lower level, which is about 1.5 billion years old at the top (green). This large unconformity indicates a period of erosion between two periods of deposition.
Many of the formations were deposited in warm shallow seas, near-shore environments (such as beaches), and swamps. The seashore repeatedly advanced and retreated over the edge of a proto-North America.
The great depth of the Grand Canyon and especially the height of its strata (most of which formed below sea level) was caused by 5,000 to 10,000 feet (1500 to 3000 m) uplift of the Colorado Plateau. This started about 65 million years ago during the Laramide period of orogeny (mountain-building). This uplift steepened the gradient of the Colorado River and its tributaries, which increased their speed and their ability to cut through rock.
Weather conditions during the ice ages also increased the amount of water in the Colorado River drainage system. The ancestral Colorado River responded by cutting its channel faster and deeper.
The base level and course of the Colorado River (or its ancestral equivalent) changed 5.3 million years ago when the Gulf of California opened and lowered the river's base level (its lowest point). This increased the rate of erosion and cut nearly all of the Grand Canyon's current depth by 1.2 million years ago. The stepped appearance of the rocks was caused by their varied resistance to the flow of water.[8]
Between three million and 100,000 years ago, volcanic activity spread ash (tuff) and lava over the area and at times completely blocked the river. These volcanic rocks are the youngest in the canyon.
## Tourism
Time Visitors [9]
before WWII >100,000
1965 1.6 million
2000 4.4 million
2019 5.9 million
Many people come from around the world to visit the Grand Canyon. People can also take trips floating on the Colorado River in boats and rafts. Some people like to hike in the Grand Canyon. The land on the north side of the Grand Canyon is called the North Rim. The land on the south side of the Grand Canyon is called the South Rim. North Rim is open to visitors from May to October. It is possible to visit South Rim all year round.
There are trails leading from the North Rim and the South Rim to the bottom of the canyon. These trails lead to a place at the bottom of the canyon called Phantom Ranch. Phantom Ranch has a campground and cabins where hikers can spend the night. Some people also ride mules into the Grand Canyon. Most people who visit the Grand Canyon drive in cars to the South Rim and just look at the canyon from the rim and take pictures. The are also free shuttles for visitors. They are a good way to go from one viewpoint to another. Many tourists like to fly over the canyon on a helicopter to have a panoramic view.
Grand Canyon admission is $35 per car. People accessing by foot or bicycle have to pay$20. Admission to Grand Canyon is included in the National Parks & Federal Recreational Lands Annual Pass (\$80), which is valid to enter all National Park in United States for a year[10].
## References
1. UNESCO, "Grand Canyon National Park"; retrieved 2012-4-18
2. Kiver, E.P.; Harris, D.V. (1999). Geology of US Parklands. Wiley. p. 902.
3. Geologic formations of the Grand Canyon National Park Service. Retrieved 2009-11-17
4. Ranney, Wayne (2005). Carving Grand Canyon: evidence, theories, and mystery. Grand Canyon Association. .
5. Polyak, Victor; Hill, Carol; Asmerom, Yemane (2008-03-07). "Age and evolution of the Grand Canyon revealed by U-Pb dating of water table-type speleothems". Science 319 (5868): 1377–1380. . .
6. Leveson, David. "The hypothesis of differential erosion". Retrieved 2010-10-22.
7.
## Other websites
Media related to Grand Canyon at Wikimedia Commons
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https://0fps.net/2012/07/12/smooth-voxel-terrain-part-2/amp/
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# Smooth Voxel Terrain (Part 2)
Last time we formulated the problem of isosurface extraction and discussed some general approaches at a high level. Today, we’re going to get very specific and look at meshing in particular.
For the sake of concreteness, let us suppose that we have approximated our potential field by sampling it onto a cubical grid at some fixed resolution. To get intermediate values, we’ll just interpolate between grid points using the standard trilinear interpolation. This is like a generalization of Minecraft-style voxel surfaces. Our goal in this article is to figure out how to extract a mesh of the implicit surface (or zero-crossings of ). In particular, we’re going to look at three different approaches to this problem:
## Marching Cubes
By far the most famous method for extracting isosurfaces is the marching cubes algorithm. In fact, it is so popular that the term marching cubes’ is even more popular than the term isosurface’ (at least according to Google)! It’s quite a feat when an algorithm becomes more popular than the problem which it solves! The history behind this method is very interesting. It was originally published back in SIGGRAPH 87, and then summarily patented by the Lorensen and Cline. This fact has caused a lot of outrage, and is been widely cited as one of the classic examples of patents hampering innovation. Fortunately, the patent on marching cubes expired back in 2005 and so today you can freely use this algorithm in the US with no fear of litigation.
Much of the popularity of marching cubes today is due in no small part to a famous article written by Paul Bourke. Back in 1994 he made a webpage called “Polygonizing a Scalar Field”, which presented a short, self-contained reference implementation of marching cubes (derived from some earlier work by Cory Gene Bloyd.) That tiny snippet of a C program is possibly the most copy-pasted code of all time. I have seen some variation of Bloyd/Bourke’s code in every implementation of marching cubes that I’ve ever looked at, without exception. There are at least a couple of reasons for this:
1. Paul Bourke’s exposition is really good. Even today, with many articles and tutorials written on the technique, none of them seem to explain it quite as well. (And I don’t have any delusions that I will do any better!)
2. Also their implementation is very small and fast. It uses some clever tricks like a precalculated edge table to speed up vertex generation. It is difficult to think of any non-trivial way to improve upon it.
3. Finally, marching cubes is incredibly difficult to code from scratch.
This last point needs some explaining, Conceptually, marching cubes is rather simple. What it does is sample the implicit function along a grid, and then checks the sign of the potential function at each point (either +/-). Then, for every edge of the cube with a sign change, it finds the point where this edge intersects the volume and adds a vertex (this is just like ray casting a bunch of tiny little segments between each pair of grid points). The hard part is figuring out how to stitch some surface between these intersection points. Up to the position of the zero crossings, there are different possibilities, each of which is determined by the sign of the function at the 8 vertices of the cube:
Some of the marching cubes special cases. (c) Wikipedia, created by Jean-Marie Favreau.
Even worse, some of these cases are ambiguous! The only way to resolve this is to somewhat arbitrarily break the symmetry of the table based on a case-by-case analysis. What a mess! Fortunately, if you just download Bloyd/Bourke’s code, then you don’t have to worry about any of this and everything will just work. No wonder it gets used so much!
## Marching Tetrahedra
Both the importance of isosurface extraction and the perceived shortcomings of marching cubes motivated the search for alternatives. One of the most popular was the marching tetrahedra, introduced by Doi and Koide. Besides the historical advantage that marching tetrahedra was not patented, it does have a few technical benefits:
1. Marching tetrahedra does not have ambiguous topology, unlike marching cubes. As a result, surfaces produced by marching tetrahedra are always manifold.
2. The amount of geometry generated per tetrahedra is much smaller, which might make it more suitable for use in say a geometry shader.
3. Finally, marching tetrahedra has only cases, a number which can be further reduced to just 3 special cases by symmetry considerations. This is enough that you can work them out by hand.
Exercise: Try working out the cases for marching tetrahedra yourself. (It is really not bad.)
The general idea behind marching tetrahedra is the same as marching cubes, only it uses a tetrahedral subdivision. Again, the standard reference for practical implementation is Paul Bourke (same page as before, just scroll down a bit.) While there is a lot to like about marching tetrahedra, it does have some draw backs. In particular, the meshes you get from marching tetrahedra are typically about 4x larger than marching cubes. This makes both the algorithm and rendering about 4x slower. If your main consideration is performance, you may be better off using a cubical method. On the other hand, if you really need a manifold mesh, then marching tetrahedra could be a good option. The other nice thing is that if you are obstinate and like to code everything yourself, then marching tetrahedra may be easier since there aren’t too many cases to check.
## The Primal/Dual Classification
By now, both marching cubes and tetrahedra are quite old. However, research into isosurface extraction hardly stopped in the 1980s. In the intervening years, many new techniques have been developed. One general class of methods which has proven very effective are the so-called dual’ schemes. The first dual method, surface nets, was proposed by Sarah Frisken Gibson in 1999:
S.F. Gibson, (1999) “Constrained Elastic Surface Nets” Mitsubishi Electric Research Labs, Technical Report.
The main distinction between dual and primal methods (like marching cubes) is the way they generate surface topology. In both algorithms, we start with the same input: a volumetric mesh determined by our samples, which I shall take the liberty of calling a sample complex for lack of a better term. If you’ve never heard of the word cell complex before, you can think of it as an n-dimensional generalization of a triangular mesh, where the cells’ or facets don’t have to be simplices.
In the sample complex, vertices (or 0-cells) correspond to the sample points; edges (1-cells) correspond to pairs of nearby samples; faces (2-cells) bound edges and so on:
Here is an illustration of such a complex. I’ve drawn the vertices where the potential function is negative black, and the ones where it is positive white.
Both primal and dual methods walk over the sample complex, looking for those cells which cross the 0-level of the potential function. In the above illustration, this would include the following faces:
### Primal Methods
Primal methods, like marching cubes, try to turn the cells crossing the bounary into an isosurface using the following recipe:
• Edges crossing the boundary become vertices in the isosurface mesh.
• Faces crossing the boundary become edges in the isosurface mesh.
• n-cells crossing the boundary become (n-1)-cells in the isosurface mesh.
One way to construct a primal mesh for our sample complex would be the following:
This is pretty nice because it is easy to find intersection points along edges. Of course, there is some topological ambiguity in this construction. For non-simplicial cells crossing the boundary it is not always clear how you would glue the cells together:
As we have seen, these ambiguities lead to exponentially many special cases, and are generally a huge pain to deal with.
### Dual Methods
Dual methods on the other hand use a very different topology for the surface mesh. Like primal methods, they only consider the cells which intersect the boundary, but the rule they use to construct surface cells is very different:
• For every edge crossing the boundary, create an (n-1) cell. (Face in 3D)
• For every face crossing the boundary, create an (n-2) cell. (Edge in 3D)
• For every d-dimensional cell, create an (n-d) cell.
• For every n-cell, create a vertex.
This creates a much simpler topological structure:
The nice thing about this construction is that unlike primal methods, the topology of the dual isosurface mesh is completely determined by the sample complex (so there are no ambiguities). The disadvantage is that you may sometimes get non-manifold vertices:
## Make Your Own Dual Scheme
To create your own dual method, you just have to specify two things:
1. A sample complex.
2. And a rule to assign vertices to every n-cell intersecting the boundary.
The second item is the tricky part, and much of the research into dual methods has focused on exploring the possibilities. It is interesting to note that this is the opposite of primal methods, where finding vertices was pretty easy, but gluing them together consistently turned out to be quite hard.
### Surface Nets
Here’s a neat puzzle: what happens if we apply the dual recipe to a regular, cubical grid (like we did in marching cubes)? Well, it turns out that you get the same boxy, cubical meshes that you’d make in a Minecraft game (topologically speaking)!
Left: A dual mesh with vertex positions snapped to integer coordinates. Right: A dual mesh with smoothed vertex positions.
So if you know how to generate Minecraft meshes, then you already know how to make smooth shapes! All you have to do is squish your vertices down onto the isosurface somehow. How cool is that?
This technique is called “surface nets” (remember when we mentioned them before?) Of course the trick is to figure out where you place the vertices. In Gibson’s original paper, she formulated the process of vertex placement as a type of global energy minimization and applied it to arbitrary smooth functions. Starting with some initial guess for the point on the surface (usually just the center of the box), her idea is to perturb it (using gradient descent) until it eventually hits the surface somewhere. She also adds a spring energy term to keep the surface nice and globally smooth. While this idea sounds pretty good in theory, in practice it can be a bit slow, and getting the balance between the energy terms just right is not always so easy.
### Naive Surface Nets
Of course we can often do much better if we make a few assumptions about our functions. Remember how I said at the beginning that we were going to suppose that we approximated by trilinear filtering? Well, we can exploit this fact to derive an optimal placement of the vertex in each cell — without having to do any iterative root finding! In fact, if we expand out the definition of a trilinear filtered function, then we can see that the 0-set is always a hyperboloid. This suggests that if we are looking for a 0-crossings, then a good candidate would be to just pick the vertex of the hyperboloid.
Unfortunately, calculating this can be a bit of a pain, so let’s do something even simpler: Rather than finding the optimal vertex, let’s just compute the edge crossings (like we did in marching cubes) and then take their center of mass as the vertex for each cube. Surprisingly, this works pretty well, and the mesh you get from this process looks similar to marching cubes, only with fewer vertices and faces. Here is a side-by-side comparison:
Left: Marching cubes. Right: Naive surface nets.
Another advantage of this method is that it is really easy to code (just like the naive/culling algorithm for generating Minecraft meshes.) I’ve not seen this technique published or mentioned before (probably because it is too trivial), but I have no doubt someone else has already thought of it. Perhaps one of you readers knows a citation or some place where it is being used in practice? Anyway, feel free to steal this idea or use it in your own projects. I’ve also got a javascript implementation that you can take a look at.
### Dual Contouring
Say you aren’t happy with a mesh that is bevelled. Maybe you want sharp features in your surface, or maybe you just want some more rigorous way to place vertices. Well my friend, then you should take a look at dual contouring:
T. Ju, F. Losasso, S. Schaefer, and J. Warren. (2004) “Dual Contouring of Hermite Data” SIGGRAPH 2004
Dual contouring is a very clever solution to the problem of where to place vertices within a dual mesh. However, it makes a very big assumption. In order to use dual contouring you need to know not only the value of the potential function but also its gradient! That is, for each edge you must compute the point of intersection AND a normal direction. But if you know this much, then it is possible to reformulate the problem of finding a nice vertex as a type of linear least squares problem. This technique produces very high quality meshes that can preserve sharp features. As far as I know, it is still one of the best methods for generating high quality meshes from potential fields.
Of course there are some downsides. The first problem is that you need to have Hermite data, and recovering this from an arbitrary function requires using either numerical differentiation or applying some clunky automatic differentiator. These tools are nice in theory, but can be difficult to use in practice (especially for things like noise functions or interpolated data). The second issue is that solving an overdetermined linear least squares problem is much more expensive than taking a few floating point reciprocals, and is also more prone to blowing up unexpectedly when you run out of precision. There is some discussion in the paper about how to manage these issues, but it can become very tricky. As a result, I did not get around to implementng this method in javascript (maybe later, once I find a good linear least squares solver…)
## Demo
As usual, I made a WebGL widget to try all this stuff out (caution: this one is a bit browser heavy):
This tool box lets you compare marching cubes/tetrahedra and the (naive) surface nets that I described above. The Perlin noise examples use the javascript code written by Kas Thomas. Both the marching cubes and marching tetrahedra algorithms are direct ports of Bloyd/Bourke’s C implementation. Here are some side-by-side comparisons.
#### Left-to-right: Marching Cubes (MC), Marching Tetrahedra (MT), Surface Nets (SN)
MC: 15268 verts, 7638 faces. MT: 58580 verts, 17671 faces. SN: 3816 verts, 3701 faces.
MC: 1140 verts, 572 faces. MT: 4200 verts, 1272 faces. SN: 272 verts, 270 faces.
MC: 80520 verts, 40276 faces. MT: 302744 verts, 91676 faces. SN: 20122 verts, 20130 faces.
MC: 172705 verts, 88071 faces. MT: 639522 verts, 192966 faces. SN: 41888 verts, 40995 faces.
A few general notes:
• The controls are left mouse to rotate, right mouse to pan, and middle mouse to zoom. I have no idea how this works on Macs.
• I decided to try something different this time and put a little timing widget so you can see how long each algorithm takes. Of course you really need to be skeptical of those numbers, since it is running in the browser and timings can fluctuate quite randomly depending on totally arbitrary outside forces. However, it does help you get something of a feel for the relative performance of each method.
• In the marching tetrahedra example there are frequently many black triangles. I’m not sure if this is because there is a bug in my port, or if it is a problem in three.js. It seems like the issue might be related to the fact that my implementation mixes quads and triangles in the mesh, and that three.js does not handle this situation very well.
• I also didn’t implement dual contouring. It isn’t that much different than surface nets, but in order to make it work you need to get Hermite data and solve some linear least squares problems, which is hard to do in Javascript due to lack of tools.
## Benchmarks
To compare the relative performance of each method, I adapted the experimental protocol described in my previous post. As before, I tested the experiments on a sample sinusoid, varying the frequency over time. That is, I generated a volume volume plot of
Over the range . Here are the timings I got, measured in milliseconds
Frequency Marching Cubes Marching Tetrahedra Surface Nets 0 29.93 57 24.06 1 43.62 171 29.42 2 61.48 250 37.78 3 93.31 392 47.72 4 138.2 510 51.36 5 145.8 620 74.54 6 186 784 83.99 7 213.2 922 97.34 8 255.9 1070 112.4 9 272.1 1220 109.2 10 274.6 1420 124.3
By far marching tetrahedra is the slowest method, mostly on account of it generating an order of magnitude more triangles. Marching cubes on the other hand, despite generating nearly 2x as many primitives was still pretty quick. For small geometries both marching cubes and surface nets perform comparably. However, as the isosurfaces become more complicated, eventually surface nets win just on account of creating fewer primitives. Of course this is a bit like comparing apples-to-oranges, since marching cubes generates triangles while surface nets generate quads, but even so surface nets still produce slightly less than half as many facets on the benchmark. To see how they stack up, here is a side-by-side comparison of the number of primitives each method generates for the benchmark:
Frequency Marching Cubes Marching Tetrahedra Surface Nets 0 0 0 0 1 15520 42701 7569 2 30512 65071 14513 3 46548 102805 22695 4 61204 130840 29132 5 77504 167781 37749 6 92224 197603 43861 7 108484 233265 52755 8 122576 263474 58304 9 139440 298725 67665 10 154168 329083 73133
## Conclusion
Each of the isosurface extraction methods has their relative strengths and weaknesses. Marching cubes is nice on account of the free and easily usable implementations, and it is also pretty fast. (Not to mention it is also the most widely known.) Marching tetrahedra solves some issues with marching cubes at the expense of being much slower and creating far larger meshes. On the other hand surface nets are much faster and can be extended to generate high quality meshes using more sophisticated vertex selection algorithms. It is also easy to implement and produces slightly smaller meshes. The only downside is that it can create non-manifold vertices, which may be a problem for some applications. I unfortunately never got around to properly implementing dual contouring, mostly because I’d like to avoid having to write a robust linear least squares solver in javascript. If any of you readers wants to take up the challenge, I’d be interested to see what results you get.
### PS
I’ve been messing around with the wordpress theme a lot lately. For whatever reason, it seems like the old one I was using would continually crash Chrome. I’ve been trying to find something nice and minimalist. Hopefully this one works out ok.
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http://philpapers.org/s/Bruce%20Sanders
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## Search results for 'Bruce Sanders' (try it on Scholar)
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1. Neville W. Bruce & Katherine A. SAnders (2001). Incidence and Duration of Romantic Attraction in Students Progressing From Secondary to Tertiary Education. Journal of Biosocial Science 33 (2):173-184.score: 1200.0
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2. Katherine A. Sanders & Neville W. Bruce (1999). Psychosocial Stress and the Menstrual Cycle. Journal of Biosocial Science 31 (3):393-402.score: 1200.0
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3. Bruce Sanders (1986). Language, Thought, and Other Biological Categories. The Review of Metaphysics 40 (1):136-137.score: 120.0
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4. score: 120.0
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5. John T. Sanders (1997). An Ontology of Affordances. Ecological Psychology 9 (1):97-112.score: 60.0
I argue that the most promising approach to understanding J.J. Gibson's "affordances" takes affordances themselves as ontological primitives, instead of treating them as dispositional properties of more primitive things, events, surfaces, or substances. These latter are best treated as coalescences of affordances present in the environment (or "coalescences of use-potential," as in Sanders (1994) and Hilditch (1995)). On this view, even the ecological approach's stress on the complementary organism/environment pair is seen as expressing a particular affordance relation between the (...)
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6. Jeffrey Fish & Kirk R. Sanders (eds.) (2011). Epicurus and the Epicurean Tradition. Cambridge University Press.score: 60.0
Machine generated contents note: 1. Introduction; 2. Autodidact and student: on the relationship of authority and autonomy in Epicurus and the Epicurean tradition Michael Erler; 3. Epicurus' theological innatism David Sedley; 4. Epicurus on the gods David Konstan; 5. Not all politicians are Sisyphus: what Roman Epicureans were taught about politics Jeffrey Fish; 6. Epicurean virtues, Epicurean friendship: Cicero vs. the Herculaneum papyri David Armstrong; 7. Cicero's use and abuse of Epicurean theology Holger Essler; 8. The necessity of anger in (...)
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7. Donald Bruce (2013). Cloning Human Embryos for Spare Tissue An Ethical Dilemma. Human Reproduction and Genetic Ethics 8 (2):22 - 23.score: 60.0
Cloning Human Embryos for Spare Tissue An Ethical Dilemma Content Type Journal Article Pages 22-23 Authors Donald Bruce, Religion and Technology Project, Church of Scotland, John Knox House, 45 High Street, Edinburgh, EH1 1SR, Scotland Journal Human Reproduction & Genetic Ethics Online ISSN 2043-0469 Print ISSN 1028-7825 Journal Volume Volume 8 Journal Issue Volume 8, Number 2 / 2002.
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8. Andy F. Sanders (1999). Polanyians on Realism. Tradition and Discovery 26 (3):6-14.score: 60.0
This introduction to a special Tradition and Discovery issue on Polanyi’s realism summarizes, and comments on the views of Jha, Gulick, Mullins, Cannon, Puddefoot, Meek and Sanders. All agree that Polanyi advocated a scientific realism hanging on the theses that reality is independent of human conceptualizations and that it is partially and fallibly knowable. Major differences concern its scope. All agree that it is comprehensive, pertaining not only to common sense and science but to intrinsic and ultimate values, and (...)
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9. Sam Sanders & Keita Yokoyama (2012). The Dirac Delta Function in Two Settings of Reverse Mathematics. Archive for Mathematical Logic 51 (1-2):99-121.score: 60.0
The program of Reverse Mathematics (Simpson 2009) has provided us with the insight that most theorems of ordinary mathematics are either equivalent to one of a select few logical principles, or provable in a weak base theory. In this paper, we study the properties of the Dirac delta function (Dirac 1927; Schwartz 1951) in two settings of Reverse Mathematics. In particular, we consider the Dirac Delta Theorem, which formalizes the well-known property ${\int_\mathbb{R}f(x)\delta(x)\,dx=f(0)}$ of the Dirac delta function. We show that (...)
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10. John T. Sanders (1988). Why the Numbers Should Sometimes Count. Philosophy and Public Affairs 17 (1):3-14.score: 30.0
John Taurek has argued that, where choices must be made between alternatives that affect different numbers of people, the numbers are not, by themselves, morally relevant. This is because we "must" take "losses-to" the persons into account (and these don't sum), but "must not" consider "losses-of" persons (because we must not treat persons like objects). I argue that the numbers are always ethically relevant, and that they may sometimes be the decisive consideration.
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11. John T. Sanders (1985). Experience, Memory and Intelligence. The Monist 68 (4):507-521.score: 30.0
What characterizes most technical or theoretical accounts of memory is their reliance upon an internal storage model. Psychologists and neurophysiologists have suggested neural traces (either dynamic or static) as the mechanism for this storage, and designers of artificial intelligence have relied upon the same general model, instantiated magnetically or electronically instead of neurally, to do the same job. Both psychology and artificial intelligence design have heretofore relied, without much question, upon the idea that memory is to be understood as a (...)
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12. John T. Sanders (1996). Stanislaw Leśniewski's Logical Systems. Axiomathes 7 (3):407-415.score: 30.0
Stanislaw Lesniewski’s interests were, for the most part, more philosophical than mathematical. Prior to taking his doctorate at Jan Kazimierz University in Lvov, Lesniewski had spent time at several continental universities, apparently becoming relatively attached to the philosophy of one of his teachers, Hans Comelius, to the chapters of John Stuart Mill’s System of Logic that dealt specifically with semantics, and, in general, to studies of general grammar and philosophy of language. In these several early interests are already to be (...)
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13. Lynn M. Sanders (1997). Against Deliberation. Political Theory 25 (3):347-376.score: 30.0
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14. John T. Sanders (2004). Retinae Don't See. Behavioral and Brain Sciences 27 (6):890-891.score: 30.0
Sensation should be understood globally: some infant behaviors do not make sense on the model of separate senses; neonates of all species lack time to learn about the world by triangulating among different senses. Considerations of natural selection favor a global understanding; and the global interpretation is not as opposed to traditional work on sensation as might seem.
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15. John T. Sanders (1992). On ‘Cuteness’. British Journal of Aesthetics 32 (2):162-165.score: 30.0
For John Morreall, cuteness is an abstract general attribute of infants that causes adults to want to care for them (or which is the reason, or at least important reason, for such solicitousness). I shall try to show, in what follows, that this is, if not an altogether fallacious way of explaining the matter, at least an extremely misleading one. As it stands, in particular, it is too easy to infer from Morreall's line of reasoning 1) that infants in general (...)
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16. Luciano Floridi & J. W. Sanders (2004). On the Morality of Artificial Agents. Minds and Machines 14 (3):349-379.score: 30.0
Artificial agents (AAs), particularly but not only those in Cyberspace, extend the class of entities that can be involved in moral situations. For they can be conceived of as moral patients (as entities that can be acted upon for good or evil) and also as moral agents (as entities that can perform actions, again for good or evil). In this paper, we clarify the concept of agent and go on to separate the concerns of morality and responsibility of agents (most (...)
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17. Suzanne C. Wagner & G. Lawrence Sanders (2001). Considerations in Ethical Decision-Making and Software Piracy. Journal of Business Ethics 29 (1-2):161 - 167.score: 30.0
Individuals are faced with the many opportunities to pirate. The decision to pirate or not may be related to an individual''s attitudes toward other ethical issues. A person''s ethical and moral predispositions and the judgments that they use to make decisions may be consistent across various ethical dilemmas and may indicate their likelihood to pirate software. This paper investigates the relationship between religion and a theoretical ethical decision making process that an individual uses when evaluating ethical or unethical situations. An (...)
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18. Glenn S. Sanders, Steven M. Platek & Gordon G. Gallup (2003). No Blind Schizophrenics: Are NMDA-Receptor Dynamics Involved? Behavioral and Brain Sciences 26 (1):103-104.score: 30.0
Numerous searches have failed to identify a single co-occurrence of total blindness and schizophrenia. Evidence that blindness causes loss of certain NMDA-receptor functions is balanced by reports of compensatory gains. Connections between visual and anterior cingulate NMDA-receptor systems may help to explain how blindness could protect against schizophrenia.
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19. Steven M. Sanders (1988). Is Egoism Morally Defensible? Philosophia 18 (2-3):191-209.score: 30.0
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20. Stacy J. Sanders & Eva Feder Kittay (2005). Shouldering the Burden of Care. Hastings Center Report 35 (5):14-15.score: 30.0
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21. Luciano Floridi & J. W. Sanders (2002). Mapping the Foundationalist Debate in Computer Ethics. Ethics and Information Technology 4 (1):1-9.score: 30.0
The paper provides a critical review of thedebate on the foundations of Computer Ethics(CE). Starting from a discussion of Moor'sclassic interpretation of the need for CEcaused by a policy and conceptual vacuum, fivepositions in the literature are identified anddiscussed: the no resolution approach'',according to which CE can have no foundation;the professional approach, according to whichCE is solely a professional ethics; the radicalapproach, according to which CE deals withabsolutely unique issues, in need of a uniqueapproach; the conservative approach, accordingto which CE (...)
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22. Luciano Floridi & J. W. Sanders (2001). Artificial Evil and the Foundation of Computer Ethics. Ethics and Information Technology 3 (1):55-66.score: 30.0
Moral reasoning traditionally distinguishes two types of evil:moral (ME) and natural (NE). The standard view is that ME is theproduct of human agency and so includes phenomena such as war,torture and psychological cruelty; that NE is the product ofnonhuman agency, and so includes natural disasters such asearthquakes, floods, disease and famine; and finally, that morecomplex cases are appropriately analysed as a combination of MEand NE. Recently, as a result of developments in autonomousagents in cyberspace, a new class of interesting and (...)
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23. Kerry Sanders (1993). Micele le Doeuff: Reconsidering Rationality. Australasian Journal of Philosophy 71 (4):425 – 435.score: 30.0
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24. Donald M. Bruce (2002). A Social Contract for Biotechnology: Shared Visions for Risky Technologies? Journal of Agricultural and Environmental Ethics 15 (3):279-289.score: 30.0
Future technological developmentsconcerning food, agriculture, and theenvironment face a gulf of social legitimationfrom a skeptical public and media, in the wakeof the crises of BSE, GM food, and foot andmouth disease in the UK (House of Lords, 2000). Keyethical issues were ignored by the bioindustry,regulators, and the Government, leaving alegacy of distrust. The paper examinesagricultural biotechnology in terms of a socialcontract, whose conditions would have to be fulfilled togain acceptance of novel applications. Variouscurrent and future GM applications areevaluated against these (...)
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25. Lynn M. Sanders (1999). Democratic Politics and Survey Research. Philosophy of the Social Sciences 29 (2):248-280.score: 30.0
Democratically inspired critics identify a number of problems with the contemporaryidentification of survey research and public opinion. Surveys are said tonormalize or rationalize opinion, to promote state or corporate rather thandemocratic interests, to constrain authentic forms of participation, and to forcean individualized conception of public opinion. Some of these criticisms arerelatively easily answered by survey researchers. But the criticisms contain acomplaint that survey researchers have largely failed to address: that surveyresearch discourages the public, visible, and face-to-face generation of opinion.Public opinion (...)
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26. Vicki Bruce, Steve Langton & Harold Hill (1999). Complexities of Face Perception and Categorisation. Behavioral and Brain Sciences 22 (3):369-370.score: 30.0
We amplify possible complications to the tidy division between early vision and later categorisation which arise when we consider the perception of human faces. Although a primitive face-detecting system, used for social attention, may indeed be integral to “early vision,” the relationship between this and diverse other uses made of information from faces is far from clear.
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27. Harry Collins & Gary Sanders (2007). They Give You the Keys and Say 'Drive It!' Managers, Referred Expertise, and Other Expertises. Studies in History and Philosophy of Science Part A 38 (4):621-641.score: 30.0
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28. Donald Bruce (2003). Contamination, Crop Trials, and Compatibility. Journal of Agricultural and Environmental Ethics 16 (6):595-604.score: 30.0
This paper examines the ethical andsocial questions that underlie the present UKdiscussion whether GM crops and organicagriculture can co-exist within a given regionor are mutually exclusive. A EuropeanCommission report predicted practicaldifficulties in achieving sufficientseparation distances to guarantee lowerthreshold levels proposed for GM material inorganic produce. Evidence of gene flow betweensome crops and their wild relatives has beena key issue in the recent Government consultation toconsult on whether or not to authorizecommercial planting of GM crops, following theresults of the current UK (...)
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29. Kim B. Bruce (1980). Model Constructions in Stationary Logic. Part I. Forcing. Journal of Symbolic Logic 45 (3):439-454.score: 30.0
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30. John Bruce (1964). Notes on Hampshire's ‘Thought and Action’. British Journal of Aesthetics 4 (1):40-46.score: 30.0
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31. Steven M. Sanders (1981). Egoism, Rationality and Community. Educational Philosophy and Theory 13 (2):51–60.score: 30.0
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32. John Bruce (1966). Art and Value. British Journal of Aesthetics 6 (2):123-134.score: 30.0
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33. B. Bruce (2000). Credibility of the Web: Why We Need Dialectical Reading. Journal of Philosophy of Education 34 (1):97–109.score: 30.0
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34. Donald Bruce (2002). Finding a Balance Over Precaution. Journal of Agricultural and Environmental Ethics 15 (1):7-16.score: 30.0
Three interpretations of theprecautionary principle are identified, namelysoft,'' hard,'' and outright rejection. The ECCommunication of February 2000 is largely aresponse to the latter, to provide alegitimation in trade-related WTO disputes.This context leads to an over stress onscientific closure. This is critiqued asidealistic in respect of resolving long termuncertainties inherent in the GM food issue.While offering some useful guidelines in riskmanagement, the EC report seriously fails totake into account the ethical and societaldimension of risk. These are crucial both indetermining when precautionary (...)
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35. Kim B. Bruce (1978). Ideal Models and Some Not so Ideal Problems in the Model Theory of L(Q). Journal of Symbolic Logic 43 (2):304-321.score: 30.0
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36. Kim Bruce & H. J. Keisler (1979). $L_a(\Finv)$. Journal of Symbolic Logic 44 (1):15 - 28.score: 30.0
The language $L_A(\Finv)$ is formed by adding the quantifier $\Finv x$ , "few x", to the infinitary logic L A on an admissible set A. A complete axiomatization is obtained for models whose universe is the set of ordinals of A and where $\Finv x$ is interpreted as there exist A-finitely many x. For well-behaved A, every consistent sentence has a model with an A-recursive diagram. A principal tool is forcing for $L_A(\Finv)$.
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37. Kathryn E. Sanders (2001). CHIRON: Planning in an Open-Textured Domain. [REVIEW] Artificial Intelligence and Law 9 (4):225-269.score: 30.0
Planning problems arise in law when an individual (or corporation)wants to perform a sequence of actions that raises legal issues. Manylawyers make their living planning transactions, and a system thathelped them to solve these problems would be in demand.The designer of such a system in a common-law domain must addressseveral difficult issues, including the open-textured nature of legal rules,the relationship between legal rules and cases, the adversarial nature ofthe domain, and the role of argument. In addition, the system's design isconstrained (...)
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38. S. A. Sanders (1986). Development of a Tool to Measure Subjective Time Experience. Nursing Research 35:178-182.score: 30.0
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39. Andries F. Sanders (2001). How Specific and Common is Common Coding? Behavioral and Brain Sciences 24 (5):903-905.score: 30.0
This commentary addresses three points. First, it is argued that the common coding principles, as developed in the target article, may supplement rather than replace stage views of human information processing. Second, the issue of the properties of an event code is briefly discussed. It is concluded that much remains to be specified so as to allow critical tests. Finally, the question of the limits of common coding is raised. It may be particularly relevant to direct perception and action coupling (...)
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40. score: 30.0
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41. Landesman Bruce (1994). Editorial. Philosophical Studies 73 (2-3):87-87.score: 30.0
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42. John Bruce (1967). For Artistic Reasons. Journal of Aesthetics and Art Criticism 25 (3):255-258.score: 30.0
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43. Darryl Bruce (1989). Review. [REVIEW] Synthese 79 (1):165-169.score: 30.0
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44. score: 30.0
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45. William J. Sanders (1940). The Logical Unity of John Dewey's Educational Philosophy. Ethics 50 (4):424-440.score: 30.0
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46. score: 20.0
This anthology will be appropriate for administrative ethics classes and professional thinking in public administration at both the masters and doctoral levels. It is a collection of administrative ethics articles published in journals of the American Society for Public Administration (ASPA) from 1941 (the earliest publication) through 1983 (the year that the first ASPA Code of Ethics was established). The articles are organized by themes of enduring importance to the field in order to provide graduate students with ready access to (...)
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47. score: 20.0
What are ethics? Why does ethical journalism matter? How do ethics affect good journalism? Ethics and Journalism provides a comprehensive overview of the main approaches to ethical enquiry in Western journalism. It examines the ethical dilemmas faced by journalists in all areas of the media and sets our ways of achieving ethical journalism. Ethics and Journalism: - Explores such subjects as: private lives and the public interest, relations to sources and coverage of death, disease and destruction - Examines the role (...)
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48. Paul D. Molnar (2007). Can the Electing God Be God Without Us? Some Implications of Bruce McCormack's Understanding of Barth's Doctrine of Election for the Doctrine of the Trinity. Neue Zeitschrift Für Systematische Theologie Und Religionsphilosophie 49 (2):199-222.score: 12.0
This article is the attempt at a dialogue with Bruce McCormack about the position he espoused in The Cambridge Companion to Karl Barth concerning the relation between God's Election of grace and God's Triunity. I had criticized McCormack's position in my book, Divine Freedom and the Doctrine of the Immanent Trinity (2002), but I did not elaborate on it in great detail. To develop the dialogue I will: 1) consider McCormack's claim that in CD II/2 Barth made Jesus Christ (...)
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49. score: 12.0
One of the more sustained efforts to think beyond current academic structures has been launched by CIRET, the International Centre for Transdisciplinary Research, in Paris. This centre was involved in the First World Congress of Transdisciplinarity, in Portugal, 1994, and another international congress in Locarno, Switzerland, in early May 1997. They have a project with UNESCO on transdisciplinarity, and are involved in the World Conference on Higher Education, to be held in Paris at the end of September 1998.
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https://www.math.wvu.edu/node/12
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# How to Apply to a Graduate Program
## General Information
This page will discuss how to apply for admission and financial aid. For your information, the Department currently has financial support for up to 27 Graduate Teaching Assistants, and generally 5 - 10 new students are admitted with teaching assistantships each year. Stipends for the 2015-2016 academic year range from about $12,700 for M.S. students to about$17,000 for Ph.D. students. There are also usually a few research assistantships, funded from external grants. All graduate assistants receive a waiver of all tuition and most fees (excepting about \$1200 in fees for the academic year), and a supplementary medical insurance plan. Limited forms of other financial aid, such as half-time assistantships, partial tuition waivers and part-time employment at the Mathematics Department, are also available. However these normally require a substantial financial commitment on the part of the student, particularly for non-residents of the State.
The Department offers programs leading to the M.S. and Ph.D. degrees. Students who have only an undergraduate degree should normally apply for the M.S. program. The Ph.D. program is intended for students who have an M.S. in mathematics or a substantially equivalent background. Some undergraduate programs outside the U.S., such as in Europe or China, often include substantial course work typically seen in the first year of graduate study, and students graduating from such programs can sometimes be offered provisional Ph.D. status with additional course work requirements. Students are invited to correspond directly with the Graduate Director for further information (see below) if they have questions about their qualifications for either of the programs.
## The Application Process
WVU provides an online portal for submitting applications and transcripts, requesting online recommendations, and submitting supporting documents. This is available through the WVU graduate office website at http://graduate.wvu.edu. If you are formally applying, this is the most convenient approach and the preferred option. Our assistantship application is available as a Word document, and can be filled out and uploaded electronically along with your application.
Applications should be completed by February 15 to ensure full consideration for financial aid in the subsequent Fall semester. Applications from students who do not require financial aid are welcome at any time, subject to University processing deadlines. Students may apply to begin in the Spring semester, but we normally do not award assistantships to new students who begin in the Spring, and course selections are limited since several key courses are year-long sequences that begin in the Fall.
The following supplementary materials are recommended in submitting your application:
1. The Department's assistantship application form as pdf or as a word document (Word 97-2003)
if you are applying for financial aid. Note that letters of recommendation requested on the form will be automatically solicited for students applying through the graduate.wvu.edu application portal.
2. Potential for success in graduate study is often hard to judge on the basis of an undergraduate academic record alone, so we invite any additional information that might reflect on your likelihood
for success in the graduate program. This is less of an issue in the case of students who have already demonstrated their ability to do graduate level mathematics through course work, publications,
or through obtaining an M.S. degree.
Please note that a decision on admission can usually be made relatively quickly and is separate from decisions on financial aid, which are made at the department level. Decisions on financial aid may take longer and depend on the overall pool of applications and the availability of funds. Also be aware that processing times for international students can sometimes require several months.
If you have any questions, or for further information, please do not hesitate to contact us by mail, fax, phone, or e-mail.
Send application materials to:
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https://arxiv.org/abs/1712.01747
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math.OA
(what is this?)
# Title:Factoriality, Connes' type III invariants and fullness of amalgamated free product von Neumann algebras
Abstract: We investigate factoriality, Connes' type ${\rm III}$ invariants and fullness of arbitrary amalgamated free product von Neumann algebras using Popa's deformation/rigidity theory. Among other things, we generalize many previous structural results on amalgamated free product von Neumann algebras and we obtain new examples of full amalgamated free product factors for which we can explicitely compute Connes' type ${\rm III}$ invariants.
Comments: 31 pages Subjects: Operator Algebras (math.OA); Dynamical Systems (math.DS) MSC classes: 46L10, 46L54, 46L55, 37A20, 37A40 Cite as: arXiv:1712.01747 [math.OA] (or arXiv:1712.01747v1 [math.OA] for this version)
## Submission history
From: Cyril Houdayer [view email]
[v1] Tue, 5 Dec 2017 16:39:01 UTC (36 KB)
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https://www.physicsforums.com/threads/second-order-coherence-g2-t-of-collision-broadened-light-and-leds.286102/
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# Second-order coherence – g2(t) of collision-broadened light and LEDs
1. Jan 20, 2009
### Xela
Hi. I have 2 questions about second-order coherence – g2(t):
1) For collision-broadened light according to the literature g2(t)=1+|g1(t)|^2, where g1(t) is the 1st order coherence. Therefore for very low collision rate g1(t) =1 and thus g2(t)=2. However I would expect collision broadened light to reach a costant phase limit of CW for low collision rate and thus g2(t)=1. What did I miss here?
2) In a light emitting diode – LED there should be many different scattering mechanisms for the radiating carriers and thus it should behave as a collision-broadened light g2(0)=2 with super-poissonian photon statistics. On the other hand the literature about LEDs talks about poissonian and even sub-poissonian photon statistics dependent only on the electron current and ignoring the scattering. Does anyone have a simple explanation of what should LED’s g2(t) look like and why?
2. Jan 20, 2009
### Cthugha
Re: Second-order coherence – g2(t) of collision-broadened light and LEDs
The above equation is an approximation for chaotic light, which is used to get g1 if g2 is known. It is not generally valid. If you go to the limit of low collision rates you also approach the monochromatic limit. In that case the light is not truly chaotic anymore and the above equation cannot be applied.
Intensity correlation measurements are mostly measurements of noise. The properties of the emitted light from LEDs depend strongly on the kinds of noise present and how strong they are. There is not only noise due to scattering, but mostly due to the emission process itself and due to pump noise. If you have access to a good library, check the book "nonclassical light from semiconductor lasers and LEDs" by Kim, Somani and Yamamoto for a more detailed study.
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http://math.stackexchange.com/questions/186421/how-to-divide-using-addition-or-subtraction
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# How to divide using addition or subtraction
We can multiply $a$ and $n$ by adding $a$ a total of $n$ times.
$$n \times a = a + a + a + \cdots +a$$
Can we define division similarly using only addition or subtraction?
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Do you admit logarithms? If so, we can very easily define division using subtraction: $$a/b = \exp\left(\log \frac{a}{b}\right) = \exp(\log a - \log b).$$ – Emily Aug 24 '12 at 18:14
doesn't exponents and logarithms come we define multiplication and division – Monkey D. Luffy Aug 24 '12 at 18:19
Nope. We can define exponents and logarithms without requiring multiplication or division -- in a manner of speaking. We define $b^x$ as the supremum of a very specific subset of real numbers. This definition does not require that we define $b^x = b\cdot b \cdot b \cdots b$ some $x$ times. In fact, this definition works for any possible value of $x$. Logarithms can be defined in a similar manner. To justify this definition, we require that multiplication is an assumed property of the field of real numbers. We don't need to define exponentiation as repeated multiplication. – Emily Aug 24 '12 at 18:43
Reminded me this good old question. – user2468 Aug 25 '12 at 2:41
@Arkamis, what is this set whose supremum is $b^x$? Sounds very interesting. – goblin Dec 25 '14 at 7:06
To divide $60$ by $12$ using subtraction:
\begin{align*} &60-12=48\qquad\text{count }1\\ &48-12=36\qquad\text{count }2\\ &36-12=24\qquad\text{count }3\\ &24-12=12\qquad\text{count }4\\ &12-12=0\qquad\;\text{ count }5\;. \end{align*}
Thus, $60\div 12=5$.
You can even handle remainders:
\begin{align*} &64-12=52\qquad\text{count }1\\ &52-12=40\qquad\text{count }2\\ &40-12=28\qquad\text{count }3\\ &28-12=16\qquad\text{count }4\\ &16-12=4\qquad\;\text{ count }5\;. \end{align*}
$4<12$, so $64\div 12$ is $5$ with a remainder of $4$.
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I remember re-implementing the built-in integer division and modulo functions of (insert language here) being a common programming exercise... :D – J. M. Aug 24 '12 at 23:45
@J.M. I had it on an exam; language was assembly for Zilog Z80 processors! – user2468 Aug 25 '12 at 3:37
Note this is horribly inefficient, computationally speaking. – Thomas Aug 25 '12 at 4:44
If $n$ is divisible by $b$ ($\frac{n}{b}$ is a whole number), then keep doing $n - b - b - b - b - b - \cdots - b$ until the value of that is $0$. The number of times you subtract $b$ is the answer. For example, $\frac{20}{4} \rightarrow 20 - 4 - 4 - 4 - 4 - 4$. We subtracted '$4$' five times, so the answer is $5$.
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You can also use additions. One should use results from intermediate calculations to speed up.
Let us divide 63 by 12. $$\begin{split} 12+12=24,&\qquad\textrm{count }1+1=2\\ 24+24=48,&\qquad\textrm{count }2+2=4\\ 48+24=72,&\qquad\textrm{count }4+2=6\textrm{ (exceeded 63)}\\ 48+12=60,&\qquad\textrm{count }4+1=5\textrm{ (so we try adding less)}\\ 63-60=3,&\qquad\textrm{(calculation of the remainder)}\\ \end{split}$$
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You can define division as repeated subtraction:$${72\over 9}=72-9-9-9-9-9-9-9-9$$Subtracting by $9$ eight times is the same as subtracting by $72$ since $9\cdot8=72$. So, the answer is $8$. Also, this is why ${n\over a}=n-a-a-a-a\cdots$ for whatever whole number $a$ is other than zero.
If you have a remainder, then you just do this:$${13\over 2}=13-2-2-2-2-2-2-1$$as you just saw, subtracting by $2$ six times is the same as subtracting by $12$ since $2\cdot6=12$, but there's a remainder of $1$ being sutracted, so it's the same as subtracting by $13$ since $2\cdot6+1=13$, so the answer is $6$ R$1$ or $6.5$.
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$\frac{n}a\neq n-a-a-a\ldots$. Certainly it is not true that $$\frac{72}{9}=72-9-9-9-9-9-9-9-9$$ – Milo Brandt Jan 24 '15 at 22:27
Okay, I edited it so it would make more sense. – ReliableMathBoy Jan 24 '15 at 22:33
Here's a diagram to visualize how to divide with subtraction. In this diagram we divide $20$ by $3$ and leave a remainder of $2$.
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http://www.earthtech.org/experiments/fusor/bigsys3.html
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EarthTech's Farnsworth Fusor - Version 2....................................117MAR99
This photo shows our implementation of the Farnsworth Fusor. It is housed in a 6" Conflat cross. The outer grid is about 3.9" OD, made of 0.062" diameter 308 stainless wire (welding rod) spot welded. A portion of the outer grid can be seen in the photo as three dark lines crossing the viewport. The inner grid is 1.25" OD, made of 0.020" diameter Ta wire spot welded. This grid is glowing visibly in the photo.
The inner grid is supported by a 0.094" diameter stainless rod which is part of the 30 kV feedthrough visible on top of the chamber. The stainless rod is insulated with a 99.8% alumina ceramic tube that tends to glow alarmingly red during operation!
By carefully adjusting the D2 pressure to around 10-15 millitorr (measured with a capacitance manometer) and applying about 20,000 volts across the grids, a thin glow discharge can be established. The current is typically around 6 milliamps. Under these conditions, the system produces D+D fusion in the center due to head-on collisions between ~20 keV deuterons.
Evidence of this fusion reaction is the emission of ~104 neutrons/sec. Neutrons are detected with a Bicron BC-720 fast neutron scintillator which consists of ZnS(Ag) phosphor embedded in a clear hydrogenous plastic. It is 2" in diameter. We have coupled it to a 2" PM tube (bi-alkali photocathode) and enclosed it in the cardboard tube visible on the left. The detector electronics are visible in the lower left corner. That box is the all-in-one (HV supply, amplifier, single-channel analyzer, and scaler) Texas Nuclear 9200 system that was originally sold as portable XRF system in the 1960's and 1970's.
The total neutron emission rate was calculated from the observed count rate of up to 1.5 count/sec (background is 0.2 count/sec), taking into account the 1/36 geometry factor and 0.6% detector efficiency for 2.5 MeV neutrons.
In front of the chamber is an 8mm thick sheet of yellowish leaded glass that does an excellent job of stopping the torrent of soft x-rays that pours out of the glass viewport during operation.
At the very top of the photo you can see the Plastic Capacitor's HV power supply and a neon sign transformer. The secondary of this transformer is wired in series with the chamber to serve as a filter. It's inductance measures 190 henries!
Neutron Detector Details
One of the advantages of the BC-720 is gamma rejection. The following waveforms, collected from the amplifier output of the TN9200, show how this is accomplished:
..................
The left waveform shows a typical gamma pulse. This waveform was generated by exposing the detector to a large piece of 232Th, which emits multiple gamma energies up to 2.6 MeV. The waveform on the right was collected during operation of the fusor. A single-channel analyzer is used to discriminate against small the pulses, making the detection system essentially insensitive to gammas.
We also looked at some background pulses. As our system is presently adjusted, background pulses occur approximately once every 5 seconds. Some of these pulses look just like the neutron pulse shown on the right above. Occassionally, there are some odd ones:
................
The background pulse on the left is very narrow compared to either the gamma or neutron pulses. The background pulse on the right is huge! Presumably these are different forms of cosmic radiation.
Power Balance
Under the optimal operating conditions mentioned above, our fusor consumes about 102 watts of power from the HV supply. With this input it stimulates enough D+D fusion to create about 104 neutrons/sec. Each of the neutron-forming D+D reactions releases 3.27 MeV. Presumably there are also about an equal number of undetectable D+D reactions occurring that yield 3H, a proton, and 4.03 MeV. Thus the total energy yield per emitted neutron is about 7 MeV. At 104/sec, that's a total fusion power output of 10-8 watts!!!....10-10 of the input power.
Counting the heat power generated by this experiment, the observed ratio of Pout/Pin is therefore about 1.0000000001. Yes, EarthTech has finally observed the excess heat phenomenon! Now we just need to make it bigger...a lot bigger!
Thanks to Richard Hull for generous technical support of our efforts!
[email protected]
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https://cozilikethinking.wordpress.com/2014/12/28/algebraic-geometry-2-philosophizing-categories-2/
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### Algebraic Geometry 2: Philosophizing Categories
Faithful functor: Let $F:A\to B$ be a functor between two categories. If the map Mor$(A,A')\to$ Mor$(F(A),F(A'))$ is injective, then the functor is called faithful. For example, the functor between the category of sets with only bijective mappings qualified to be morphisms between objects, to the category of sets with all kinds of mappings allowed to be morphisms, carrying objects and morphisms to themselves, is faithful.
Full functor: If Mor$(A,B)\to$ Mor$(F(A),F(B))$ is surjective, then the functor is called full. For example, the functor defined above is not full.
Natural transformation of covariant functors: Let $F,G$ be functors between categories $A$ and $B$. Let $M,M'\in A$ be objects, and let $f:M\to M'$ be morphisms between them. Then $m:F\to G$ is a natural transformation if the following diagram commutes:
Philosophical point: Why are commutative diagrams so omnipresent and important in Mathematics? It seems to be a fairly arbitrary condition to satisfy! Commuting diagrams essentially signify that “similar things” are happening at “different places”, and the “similar things” can easily be inter-converted. Too hand-wavy? Please bear with me.
Say $M,M',F(M),F(M'),G(M),G(M')$ are all $\Bbb{Z}$, and $m(\Bbb{Z})$ is idenity. Also assume that $F(f)$ maps $k\to k+1$. Then if $G(f)$ also maps $k\to k+1$, then $m$ is a natural transformation. However, if $G(f)$ is of any other description, then $m$ is not a natural transformation.
Forming other examples should convince you of the fact above.
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https://lexique.netmath.ca/en/formula/
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# Formula
## Formula
Name given to certain fundamental relationships between variable quantities and constants.
### Examples
• The formula to calculate the perimeter P of a square of side length c is : P = 4c.
• The formula to calculate the volume V of a ball of radius r is : V = $$\dfrac{4πr^3}{3}$$.
• Euler’s formula is a formula that relates the number of vertices S, the number of faces F and the number of edges A of a convex polyhedron : S + F = A + 2.
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https://docs.nvidia.com/deeplearning/dali/user-guide/docs/operations/nvidia.dali.fn.mxnet_reader.html
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nvidia.dali.fn.mxnet_reader(*inputs, **kwargs)
This operator is now deprecated. Use readers.mxnet() instead.
In DALI 1.0 all readers were moved into a dedicated readers submodule and renamed to follow a common pattern. This is a placeholder operator with identical functionality to allow for backward compatibility.
Legacy alias for readers.mxnet().
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https://www.physicsforums.com/threads/universal-gate-question.798536/
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# Universal gate question
1. Feb 18, 2015
### braceman
Hi guys, got a question that's got me stumped. Not looking for the answer as I'd prefer to work it out myself, just a nudge or a pointer in the right direction.
I'm being asked to prove if an XOR gate can be classed as universal (like the NAND & NOR gates are), but not sure how to go about it. I think there must be a simple way to do it, rather than draw numerous combinations of XOR gates.
1. The problem statement, all variables and given/known data
Determine the elementary operations that can be derived from XOR and hence determine if it is a universal gate.
2. Relevant equations
3. The attempt at a solution
Obviously got the truth table for XOR, am I supposed to be manipulating this, or taking a function, ie - F = A.B + C. not A and then trying to manipulate this like we do when converting to NAND/NOR (changing gates and inverting terms etc).
Bit stuck, so any pointers would be grateful.
Last edited by a moderator: Feb 18, 2015
2. Feb 18, 2015
### lewando
Sorry, misread your post. Look into definitions or requirements of a universal gate.
Last edited: Feb 18, 2015
3. Feb 18, 2015
### phinds
To prove that gate type X is "universal", you just need to show that the Boolean functions AND, OR, and NOT can be implemented using only gate type X without the need for any other type gate. Can you do that with an XOR gate?
4. Feb 18, 2015
### donpacino
Or prove that you can make a single NOR or NAND gate
5. Feb 18, 2015
### donpacino
here is a hint. first see if you can make an inverter
then see if you can make any input a 'blocker.' an example of that is an and gate, if any input is a zero, the ouput will be zero, independent of any other input
6. Feb 19, 2015
### LCKurtz
Here's another hint: Try to prove you can't make an AND gate. (I don't think this is so easy to show if you haven't seen an argument before though).
7. May 11, 2015
### braceman
Sorry I haven't posted back.....forgot all about this post. I got it right in the end, Instructor said I could prove it however I wanted, so I just drew various combinations of 3-4 gates and their associated logic.
8. Jan 20, 2016
### bizuputyi
Is it correct that AND and OR cannot be derived from XOR at all?
9. Jan 20, 2016
### phinds
what do you think, and why?
10. Jan 20, 2016
### bizuputyi
What I meant is that an AND or OR gated cannot be derived by using only XOR gates. We can however make an inverter out of a XOR gate by connecting constant high to one of its input but I can't see any possible way to get either AND or OR from only XORs. To account for that I would say XOR gives high output only if its two inputs differ.
11. Jan 20, 2016
### phinds
I agree.
Draft saved Draft deleted
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28 May 2008, 13:57
It seems that so many people on here are focused on the quant section. Any ideas as to why this seems to be the case? Maybe it seems this way to me because I spend a lot of time on the Quant because that's where I need to improve the most. I need improvement with Verbal, but not as drastically as Quant. Got 66% on quant, 84% on verbal first time around.
Anyone else think there is more of a focus on quant in the forums?
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# If m and n are integers, is m odd?
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If m and n are integers, is m odd? [#permalink]
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14 Jul 2010, 13:44
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If m and n are integers, is m odd?
(1) n + m is odd
(2) n + m = n^2 + 5
[Reveal] Spoiler: OA
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14 Jul 2010, 13:46
zisis wrote:
if m and n are integers, is m odd?
(1) n+m is odd
(2) n+m = n^2 + 5
1 is insuf
2 is insuf for me
let me explain:
m = n^2 - n + 5
thus, if n =0, m=1-0+5= 6 thus even
if n=1, m=1-1+5 = 5 thus odd...
what am i missing?
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14 Jul 2010, 13:55
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(1) n,m could be odd,even ore even,odd. insufficient
(2) m = n^2 - n + 5 or m = odd|even - odd|even + odd = (odd - odd)|(even - even) + odd = even + odd = odd. sufficient.
zisis wrote:
if m and n are integers, is m odd?
let me explain:
m = n^2 - n + 5
thus, if n =0, m=1-0+5= 6 thus even
if n=1, m=1-1+5 = 5 thus odd...
what am i missing?
0^2 = 0.
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14 Jul 2010, 13:57
walker wrote:
(1) n,m could be odd,even ore even,odd. insufficient
(2) m = n^2 - n + 5 or m = odd|even - odd|even + odd = (odd - odd)|(even - even) + odd = even + odd = odd. sufficient.
zisis wrote:
if m and n are integers, is m odd?
let me explain:
m = n^2 - n + 5
thus, if n =0, m=1-0+5= 6 thus even
if n=1, m=1-1+5 = 5 thus odd...
what am i missing?
0^2 = 0.
aaaaaaaaaaaaaaaaaaaaaaaaaa
it s the other way round
2^0 = 1 and not 0^2 = 1
aaaaaaaaaa
going mental
thanks
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If m and n are integers, is m odd?
(1) n + m is odd --> $$n+m=odd$$. The sum of two integers is odd only if one is odd and another is even, hence $$m$$ may or may not be odd. Not sufficient.
(2) n + m = n^2 + 5 --> $$m-5=n^2-n$$ --> $$m-5=n(n-1)$$, either $$n$$ or $$n-1$$ is even hence $$n(n-1)=even$$ --> $$m-5=m-odd=even$$ --> $$m=odd$$. Sufficient.
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Re: If m and n are integers, is m odd? [#permalink]
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16 Aug 2013, 06:22
m and n are integers, is m odd?
-Can't rephrase the question here, so you work with m = odd? It's a Yes/No DS question type.
Here's how I approached the problem.
Statement 1.
Given: m + n is odd.
Using even/odd number property rules:
even + odd = odd. OR, odd + even = odd. Since m can be either even or odd in this case, Statement 1 is insufficient, we don't have enough information.
Statement 2.
Given: $$m+n = n^2 + 5$$
Simplifying the equation:
$$m - 5 = n^2 - n$$
$$m - 5 = n(n - 1)$$
$$m = n(n-1) +5$$
m = Even + odd. Therefore, m is odd.
n(n-1) will always be even because it's a number times the number preceding it (think consecutive)...so one of those numbers has to be even (if n = 3 for example, you would have 3*(3-1) = 3*(2) = 6). You have an even*odd = even situation here.
5 is odd. So putting it all together, m = Even + Odd. You can answer with the given information that, yes, m is odd. Sufficient.
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Re: If m and n are integers, is m odd? [#permalink]
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23 Nov 2013, 05:04
Statement 1, m and n could be both odd or one odd, one even. Insufficient.
Statement 2, when n is odd, n^2+5 is even, then m+n is even, m is odd; when n is even, n^2+5=odd, m+n is odd,
then m is odd. Sufficient.
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28 Mar 2014, 01:11
Bunuel wrote:
If m and n are integers, is m odd?
(1) n + m is odd --> $$n+m=odd$$. The sum of two integers is odd only if one is odd and another is even, hence $$m$$ may or may not be odd. Not sufficient.
(2) n + m = n^2 + 5 --> $$m-5=n^2-n$$ --> $$m-5=n(n-1)$$, either $$n$$ or $$n-1$$ is even hence $$n(n-1)=even$$ --> $$m-5=m-odd=even$$ --> $$m=odd$$. Sufficient.
Another method:
St1: n + m is odd, Answer is YES when n is even but answer is NO when n is odd.
Insufficient!
St2: n + m = n^2 + 5 --> n^2 - n + (5-m) = 0 -- > is a quadratic equation with sum of roots = 1 and product of roots = (5-m). Clearly the the roots are consecutive integers with least among them as negative (ex. 4 & -3, 6 & -5...) That means one of the root is even. So, product of roots (5-m) is also even. For (5-m) to be even, m must be odd.
Sufficient!
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Re: If m and n are integers, is m odd? [#permalink]
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28 Mar 2014, 08:22
Satatment 1:Clearly insuff.
Even+odd=odd.So m could be even or odd.
S2:sufficient.
The eq can be rearranged as
N(n-1)=m-5
Now n(n-1) is a product of 2 consecutive integers so it'll definitely be even=>m-5=even
So m=odd because only odd-odd=even
Ans option B
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Re: If m and n are integers, is m odd? [#permalink]
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Re: If m and n are integers, is m odd? [#permalink]
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14 May 2015, 17:02
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Hi All,
Even though this is an old post (and most of the original posters are probably long gone), this question serves as a nice example of some of the Number Properties that you're likely to face on Test Day. If you can spot the NPs involved, then you can move relatively quickly through the work, but even if you don't recognize the NPs, you can still TEST VALUES to prove that patterns exist. In that way, you can do some quick work and avoid "staring at the screen" and hoping that something comes to you.
We're told that M and N are INTEGERS. We're asked if M is ODD. This is a YES/NO question.
Fact 1: N + M is ODD
IF....
N = 1
M = 0
The answer to the question is NO
IF....
N = 0
M = 1
The answer to the question is YES
Fact 1 is INSUFFICIENT
Fact 2: N + M = N^2 + 5
Here, the value of M depends on the value of N. Let's start with something simple and see if a pattern emerges.
IF....
N = 0
M = 5
The answer to the question is YES
IF....
N = 1
M = 5
The answer to the question is YES
IF....
N = 2
M = 7
The answer to the question is YES
IF....
N = 3
M = 11
The answer to the question is YES
It certainly looks like the answer to the question is ALWAYS YES. We can quickly TEST some negative values for N and see what happens....
IF....
N = -1
M = 7
The answer to the question is YES
IF....
N = -2
M = 11
The answer to the question is YES
Fact 2 is SUFFICIENT
[Reveal] Spoiler:
B
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Re: If m and n are integers, is m odd? [#permalink]
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15 May 2015, 00:48
very tricky, I missed this question.
not hard but enough to kill us
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Re: If m and n are integers, is m odd? [#permalink]
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Re: If m and n are integers, is m odd? [#permalink]
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02 Jun 2016, 10:25
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zisis wrote:
If m and n are integers, is m odd?
(1) n + m is odd
(2) n + m = n^2 + 5
1) n + m is odd
It can be odd+even or even +odd. m can be even or odd. Not sufficient.
(2) n + m = n^2 + 5
Let's suppose n is odd, n^2 will also be odd. Hence to maintain the equality m must be odd.
Let's suppose n is even, n^2 will be even. And to maintain the equality m must be odd.
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Re: If m and n are integers, is m odd? [#permalink]
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11 Oct 2016, 05:07
zisis wrote:
If m and n are integers, is m odd?
(1) n + m is odd
(2) n + m = n^2 + 5
A) m + n = odd
Two possibilities :-
1- m is odd and n is even : 1 + 2 = 3
2- m is even and n is odd : 2 + 1 = 3
Two possibilities, :. Insufficient
B) m+n = n^2 + 5
Solve
m + n - n^2 = 5
m + n(1-n) = 5
n(1-n) {can say one is odd other is even like consecutive numbers}
:. m + n(1-n) [even] = 5 [odd]
This is only possible when m is odd
as Odd + Even = Odd
Hence (B)
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Re: If m and n are integers, is m odd? [#permalink]
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21 Nov 2016, 11:15
Great Question
Here we are given two integers m,n
And we are asked if m is odd or not
Statement 1
m+n=odd
hmm
This Statement just tells us that m and n are of opposite even/odd nature
Not sufficient
Statement 2
m=n(n-1)+5
here n(n-1) is a product of two consecutive integers. hence it must be even
so n=even+5 => even+odd => odd
hence sufficient
hence B
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Re: If m and n are integers, is m odd? [#permalink]
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21 Nov 2016, 11:28
zisis wrote:
If m and n are integers, is m odd?
(1) n + m is odd
(2) n + m = n^2 + 5
FROM STATEMENT - I ( INSUFFICIENT )
If n + m = Odd
Either n = Odd/Even and m = Odd/Even because -
1. Even + Odd = Odd
2. Odd + Even = Odd
FROM STATEMENT - II ( INSUFFICIENT )
n - n^2 = 5 - m
Or, n ( n - 1 ) = 5 - m
Here, LHS must be Even, because product of 2 consecutive integers is always even ( ie, one of the 2 consecutive numbers must be even )
So, 5 - m = Evem
Or, Odd - m = Even
Hence, m = Odd
Thus, Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked, answer will certainly be (B)...
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https://puzzling.stackexchange.com/questions/67608/a-space-station-13-complicated-escape
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# A Space Station 13 complicated escape
After successfully resolving this tricky situation, you, the Captain of the Space Station 13, have ordered what remains of your crew to gather in the escape shuttle. Accompanied by the Security Officer, the Chief Engineer, the Medical Doctor and the Clown, you enter the shuttle and find two additional survivors hidden there: the Roboticist and the Chaplain. Everyone is quite happy to be alive, and you quickly enter the cockpit to start the launching countdown.
But then, the ship A.I. begins talking to you:
Hello Captain. I have some troublesome readings on the situation. It appears
that, despite your previous work, there are still hostile elements in the
shuttle. There is one Syndicate Nuclear Operative that planted a bomb
somewhere; one innocent crewmember that was infected by an alien lifeform,
known as a "Facehugger", and reluctant to seek help; one Rogue Cyborg with a
perfect human disguise but defective Asimov's laws; and another Changeling
who wears the skin of one of his victims. Their identities are...
There was one long pause.
I'm sorry Captain, I'm afraid someone tampered with my laws. I will now
Hopefully, none of the crew heard that, and you know that it falls on you to find out who is who and take the necessary measures, again. You'll have to interrogate the crew without raising suspicion, and act swiftly with the help of your beloved laser gun before any antagonist can react.
But first, you assess the situation: the four antagonists the A.I. told you about will lie, it's a fact. And one of them is also responsible for hacking the A.I., and you'll have to know who. The Syndicate Nuclear Operative, or Nuke Op, had planted a bomb: that means he had to be alone in the past hour, which includes the time even before you met on the previous situation... You expect the Facehugged poor guy and the Changeling to act weird, the first out of fear to be euthanised to prevent the alien's growth, the other of not knowing its host's personality. No reason to act weird apart from that. Also, the Facehugged one would have been alone during the "act" in the past hour, or at least with another antagonist, or else an innocent person would have told already. And the Changeling could not have tampered with the A.I. even if impersonating someone who had the knowledge to do so. On the contrary, the Rogue Cyborg would be totally able to do that, whoever he is.
That's a good start, but now you ponder on the crew personnalities: the Medical Doctor can easily notice a Facehugged person, a Cyborg or a Changeling upon medical inspection. The Roboticist and the Chief Engineer are both able to hack the A.I., even with someone else in the room (they're really good at it). The Chaplain, you know him, is compelled to say the truth, even if an antagonist. However, as a Changeling he would not really be the Chaplain, and would still lie... The Security Officer, if an antagonist, would have killed you already... unless Facehugged. And as for the Clown, well... he stuck with you for the whole last two hours, severely annoying you with his stupid pranks but never acting weird.
Now is the time for questioning. Since you want to do it without raising suspicions, you can't ask hard questions. Still, you try your best:
-So, you were with the Roboticist all this time?
-Yes indeed.
Then you ask the Security Officer:
-Did you see anything unusual?
-Well, the Chaplain acted weird lately.
You thank him and go to the Medical Doctor:
-Did you make a medical inspection of some crewmembers in the past hour?
-Yes, of the Roboticist and Chief Engineer. Nothing unusual about those two.
-So, you were with the Chaplain all this time?
-No, he went out of the shuttle at least once.
You nod, quite perplexed, and go on with the Chief Engineer:
-Before we got together, what were you doing in the past hour?
-I was with the Security Officer the whole time. Also, I heard your conversation with the Medical Doctor, and he lied!
Something is definitly going on there, and you finish by interrogating the Clown:
-Any prank you played lately?
-Yeah, I slipped some drug in the Security Officer's coffee; he can only lie now!
Now, with all these informations, you have to guess:
• Who got Facehugged, so you can help him (if the Medical Officer is innocent) or shoot him in the chest.
• Who is the Changeling, so you can shoot him in the head.
• Who is the Rogue Cyborg, so you can shoot him in the head.
• Who is the Nuclear Operative, so you can force him to defuse the bomb. And then shoot him in the head.
• And finally, which one of them hacked the A.I., so you can ask him nicely how to hack it back to normal (before shooting him, obviously).
Good luck!
It is not necessary to read the previous puzzle, even if it continues on the same story (and is a cool puzzle). The current puzzle is a different one which can work as a pure standalone. For exemple, the fact that a crewmember was deemed innocent then means nothing now.
If you liked this puzzle, try the rest of the story!
• For calrification: if one of the liars makes two statements, are both of those always lies? e.g. Chief Engineer? – Mohirl Jun 28 '18 at 10:55
• @Mohirl yes, a liar lies on both statements. – Keelhaul Jun 28 '18 at 11:31
• Thanks. Another question though: if the Security Officer was a liar, would the Clown's drug make him flip to telling the truth, or would he just keep lying? – Mohirl Jun 28 '18 at 11:36
• @Mohirl As the Clown stated "he can only lie", even if he already was about to tell a lie. – Keelhaul Jun 28 '18 at 11:38
• Need a small clarification: by "which include the time even before you met on the previous situation" you mean Nuke Op can't be one of the 4 that were with you? Also: If an antagonist makes 2 statements, are they BOTH a lie? – George Menoutis Jun 28 '18 at 13:20
As currently constructed there is no solution.
The solution is below
Firstly I will prove that the doctor cannot be Normal by contradiction. Thus we assume the doctor is normal.
Given that the doctor is normal, the Robo end Engineer must either be normal, or syndicate members. Since we have at most 2 normal members, and the doc + robo/engineer is normal, we know that the Security Off is FaceHugged (or you'd be a goner).
Now we can figure out the clown
Given that we were with the clown the entire time, and he wasn't acting weird, he must be the cyborg (as the faceHug/changer make people weird, and a syndicate member needs alone time). This means by process of elimination the chaplain is Change. However this is a contradiction. We know that the Security is a liar bc he is a Face. Yet the opposite of his statement in that the Chap is acting weird implies the Chap is acting normally. Yet a Change does not act normally.
Nextly, I will prove why the clown also cannot be normal also by contradiction.
From above, we know the doctor is not normal and thus will be lying in his statement. As the Engineer states the doctor is lying, this is true making the Engineer normal. Once again given 2 normal people, we know the Security Officer must be a face (or you'd be a goner). However this is a contradiction, as we know the face must be alone for some time for the transformation, and the engineer stated they were together the entire time.
Finally,
From above, we know the clown must by the cyborg. (We stood with him and he hasn't acted weird, nor can he be a syndicate member as we are together, and we proved he isn't normal from above). From above, we know that the engineer must be normal as the doctor isn't. And to avoid the prior contradiction we must say that the Security Officer is the other normal person. This leaves us with the chaplain, the doctor and the robo guy for the 3 roles of Syndicate, FaceHug, and Changer.
The permutations are
Robo guy is a syndicate member. As a syndicate member he would need to be alone to plant the device. However, if his statement is truly a lie, he would have been with the Chaplain the entire time, thus a contradiction.
Next
Robo guy is a faceHugger. For the chaplain, we know that he must be acting weird (as the SO is normal and a truth teller) so he must be the changeling. A changeling Champlain is a liar, so he will be lying that he was with the robo guy the entire time. However this is a contradiction, because it would mean his statement would be true even though we have just said he is a faceHugger.
Lastly,
By process of elimination Robo guy is a changeling. This wrong because nobody could have tampered with the AI. The cyborg is with you, the Changeling Robo guy is incapable, and the Engineer is normal. After OPs edit, this provides that the clown as a cyborg could have tampered with the AI removing this contradiction. Figuring out the last 2 is easy. The Chaplain was with the robo guy the entire time and thus can't be the syndicate member. Thus the Chaplain is the FaceHugger, and the Doctor is the syndicate member.
In conclusion:
Security Officer and Engineer are normal. The chaplain is FaceHugged and can't be saved because the Doctor is the syndicate member. The Roboticist is the Changeling, and the Clown is the Rogue Cyborg. You must get the doctor to defuse the device, and ask the Clown to nicely unhack the device (or maybe ask the Engineer? He seems smart...)
• The error lies on what may be an imprecision of mine. I stated that both the Roboticist and Chief Engineer are "able to hack the A.I., even with someone else in the room", and this statement holds true for the Cyborg (even if not clearly stated). Also, it is implied the A.I. was hacked when you where alone in the cockpit just after receiving news from the A.I. (not clear either I confess). – Keelhaul Jun 28 '18 at 20:21
• @Keelhaul I still believe that my contradictions still hold, I never relied on that fact, could you double check my work/yours to see the inconsistency? – qwertylpc Jun 29 '18 at 18:29
• @keelhaul oh you are saying that a cyborg clown could have tampered with the AI – qwertylpc Jun 29 '18 at 18:37
• Indeed, and you got all right now ;) – Keelhaul Jun 30 '18 at 8:27
• Nice puzzle cheers – qwertylpc Jul 10 '18 at 14:40
Ok, I missed the fact that the cyborg cannot hack in secret. Now the solution is:
Engineer: innocent
security: innocent
doctor: nukeOp
roboticist: facehugger + hacker
chaplain: changeling
clown: cyborg
The fixed program:
% define all people and the secret roles
people([security,engineer,doctor,clown,roboticist,chaplain]).
roles([innocent,nukeOp,facehug,changeling,cyborg]).
% we store knowledge about a crew members identity in a term id(Role,Person,Hacker)
% variable ID refers to a single member, variable All to the entire crew
% initially, our only knowledge is that there are two innocents and one of every evil role
all([id(innocent,_,_)|More]) :- roles(Roles), findall(id(R,_,_),member(R,Roles),More).
% this filters duplicate solutions where the two innocents are swapped
noDups([id(_,A,_),id(_,B,_)|_]) :- ((var(A),var(B));(nonvar(A),var(B)); (nonvar(A),nonvar(B),compare(<, A, B))),!.
% predicates to check if a crew member is a person or role or hacker
isPerson(P) :- people(Pps), member(P,Pps).
isPerson(id(_,P,_), P) :- isPerson(P).
isRole(R) :- roles(Rs), member(R,Rs).
hasRole(id(R,_,_), R) :- isRole(R).
isHacker(id(_,_,1)).
% negation can be tricky in Prolog,
% to avoid bugs we use explicit negation predicates
isNotPerson(ID, P) :- isPerson(P), isPerson(ID,P2), P \= P2.
hasNotRole(ID, R) :- isRole(R), hasRole(ID, R2), R \= R2.
isNotHacker(id(_,_,0)).
% define evil, lying, and truth telling crew members
isEvil(ID) :- hasNotRole(ID, innocent).
isLiar(ID) :- isEvil(ID), (isNotPerson(ID, chaplain); hasRole(ID, changeling)), !.
isTruth(ID) :- isPerson(ID,_), hasRole(ID,_), \+ isLiar(ID).
% roboticist and engineer can hack if not innocent or changeling,
% cyborg can hack
canHackPublic(ID) :-
hasNotRole(ID, changeling), hasNotRole(ID,innocent),
(isPerson(ID, roboticist); isPerson(ID, engineer)).
canHack(ID) :-
canHackPublic(ID); hasRole(ID, cyborg).
hackingOnlyInPublic(ID) :-
canHackPublic(ID); isNotHacker(ID).
% nukeOp and facehugger needed time alone,
% but a liar would not report the facehugger
needsNoPrivacy(ID) :-
hasNotRole(ID,nukeOp), hasNotRole(ID,facehug), hackingOnlyInPublic(ID).
observedEachOther(ID1,ID2) :-
hackingOnlyInPublic(ID1), hackingOnlyInPublic(ID2),
(needsNoPrivacy(ID1); (isLiar(ID2), hasRole(ID1,facehug))),
(needsNoPrivacy(ID2); (isLiar(ID1), hasRole(ID2,facehug))).
% facehugger and changeling are weird
% facehugger, cyborg, changeling are detected by doctor
% again with explicit negation
isWeird(ID) :- hasRole(ID, facehug); hasRole(ID, changeling).
isNotWeird(ID) :- hasRole(ID,_), \+ isWeird(ID).
failInspect(ID) :- hasRole(ID, facehug); hasRole(ID, cyborg); hasRole(ID, changeling).
passInspect(ID) :- hasRole(ID,_), \+ failInspect(ID).
% we know security is innocent or facehugger,
% clown is not weird and had no privacy
factYours(All) :-
isPerson(Sec, security), member(Sec, All),
isPerson(Clwn, clown), member(Clwn, All),
(hasRole(Sec, innocent); hasRole(Sec, facehug)),
isNotWeird(Clwn), needsNoPrivacy(Clwn).
% chaplain claimed he and roboticist observed each other the entire time
% if lying we can't conclude anything
factChaplain(All) :-
isPerson(Chap, chaplain), member(Chap, All),
isPerson(Robt, roboticist), member(Robt, All),
(isTruth(Chap) ->
observedEachOther(Chap,Robt) ;
true).
% security can only tell truth if clown was lying,
% claimed chaplain is weird, when it's a lie he's not weird
factSecurity(All) :-
isPerson(Sec, security), member(Sec, All),
isPerson(Chap, chaplain), member(Chap, All),
isPerson(Clwn, clown), member(Clwn, All),
((isTruth(Sec),isLiar(Clwn)) ->
isWeird(Chap);
isNotWeird(Chap)).
% docter claimed roboticist and engineer passed inspection,
% if lie at least one failed
factDoctor(All) :-
isPerson(Doc, doctor), member(Doc, All),
isPerson(Robt, roboticist), member(Robt, All),
isPerson(Eng, engineer), member(Eng, All),
(isTruth(Doc) ->
(passInspect(Robt), passInspect(Eng)) ;
(failInspect(Robt); failInspect(Eng))).
% roboticist claimed chaplain left, this tells us nothing
% but if lie then both observed each other
factRoboticist(All) :-
isPerson(Robt, roboticist), member(Robt, All),
isPerson(Chap, chaplain), member(Chap, All),
(isTruth(Robt) ->
true;
observedEachOther(Robt, Chap)).
% engineer claimed to observe security and that doc is lying,
% if lie then doc told truth
factEngineer(All) :-
isPerson(Eng, engineer), member(Eng, All),
isPerson(Sec, security), member(Sec, All),
isPerson(Doc, doctor), member(Doc, All),
(isTruth(Eng) ->
observedEachOther(Eng, Sec), isLiar(Doc) ;
isTruth(Doc)).
% to solve, initialize the crew list, apply all facts,
% and ensure there is a hacker
solve(All) :-
all(All),
factYours(All), factChaplain(All),
factSecurity(All), factDoctor(All),
factRoboticist(All), factEngineer(All),
noDups(All),
isHacker(Hacker), member(Hacker, All),
canHack(Hacker).
Calling solve(All). returns
All = [id(innocent, engineer, 0), id(innocent, security, 0), id(nukeOp, doctor, _1360), id(facehug, roboticist, 1), id(changeling, chaplain, 0), id(cyborg, clown, 0)]
• heavy-duty stuff! We certainly need the explain later part :D – George Menoutis Jun 29 '18 at 11:21
• So I guess, in order to explain the process, you will just see your program's run log? Could you please paste it into the answer so I can learn some prolog from it? – George Menoutis Jun 29 '18 at 11:27
• OK guys, I think we got the Cyborg... Great work! – Keelhaul Jun 30 '18 at 8:21
The Security Officer (SO) can't be an enemy unless they're Facehugged, which would require them being alone. But they weren't, if the Engineer is telling the truth. Therefore if the SO is an enemy the Engineer must be lying. That means the Medical Doctor (MD) is telling the truth. If the MD didn't recognise an enemy, the Engineer must be the Nuke Op. The Roboticist must be innocent. So everyone else is guilty, including the Chaplain. But the Chaplain would still be telling the truth, in conflict with the innocent Roboticist, unless he's the Changeling. But he can't be, since the Security Officer lied when he said he acted weird. So the Engineer can't be lying, so both he and the SO are innocent.
So all the others are enemies.
The only role the Clown could be is Cyborg, since being with you and not acting weird rules out the other three. The Chaplain is acting weird but telling the truth. So must be the Facehugged. They weren't alone, but that's OK because the Roboticist is an enemy. That leaves the MD and the Roboticist as Nuke Op and Changeling, but only the MD was alone, so they're the Nuke Op. The Roboticist is the changeling.
So in summary, shoot the:
Chaplain in the chest as the Facehugged, Roboticist in the head as the changeling, Clown in the head as the Rogue Cyborg, and the Medical Doctor in the head after defusing his Nuke Op bomb.
But first, get the
Roboticist, who was able to corrupt the AI even while accompanied Medical Doctor, since he was the only baddie alone (and the changeling Roboticist couldn't do it)
to fix the AI
• Good start, but I saw one mistake somewhere :) – Keelhaul Jun 28 '18 at 11:34
• Ah! I've spotted it. Grrr!!!! – Mohirl Jun 28 '18 at 11:54
• In fact, there is at least another mistake, but the first one threw your reasoning on the wrong path already so... try again^^ – Keelhaul Jun 28 '18 at 11:54
• I had at least two but couldn't work out where the original error was, so I threw it all out and started again from another angle. Think I have it this time! – Mohirl Jun 28 '18 at 14:24
• It's stated that "The Roboticist and the Chief Engineer are both able to hack the A.I." and "the Changeling could not have tampered with the A.I. even if impersonating someone who had the knowledge to do so. On the contrary, the Rogue Cyborg would be totally able to do that, whoever he is.", which kind of implies the others cannot ;) – Keelhaul Jun 29 '18 at 13:30
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http://www.onemathematicalcat.org/Math/Precalculus_obj/nonlinearInequalities.htm
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# SOLVING NONLINEAR INEQUALITIES IN ONE VARIABLE (INTRODUCTION)
• PRACTICE (online exercises and printable worksheets)
In Precalculus, it's essential that you can easily and efficiently solve sentences like ‘$\,\frac{3x}{2}-1 \ge \frac 15 - 7x\,$’ and ‘$\,x^2 \ge 3\,$’ .
The first sentence is an example of a linear inequality in one variable; the prior web exercise covers this type of sentence.
For linear inequalities, the variable appears in the simplest possible way—all you have are numbers, times $\,x\,$ to the first power
(i.e., terms of the form $\,kx\,$, where $\,k\,$ is a real number).
The second sentence is an example of a nonlinear inequality in one variable, and is covered in this web exercise and the next two.
In nonlinear sentences, the variable appears in a more complicated way—perhaps you have an $\,x^2\,$ (or higher power), or $\,|x|\,$, or $\,\sin x\,$.
For solving nonlinear inequalities, more advanced tools are needed.
To get started, review the essential concepts in these two web exercises, being sure to click-click-click to practice the concepts from each:
## Two approaches for solving nonlinear inequalities in one variable
There are two basic methods for solving nonlinear inequalities in one variable.
Both are called ‘test point methods’, because they involve identifying important intervals, and then ‘testing’ a number from each of these intervals.
Below, the sentence ‘$\,x^2 \ge 3\,$’ is solved using both methods, so you can get a sense of which appeals to you more.
The solutions below are written extremely compactly—this is pretty much the bare minimum that a teacher would want to see.
For all the underlying concepts and details, study the next two web exercises:
• the test point method for sentences like ‘$f(x) \gt 0$’
(the one-function method; the ‘compare with zero’ method)
• the test point method for sentences like ‘$f(x) \gt g(x)$’
(the two-function method; the ‘truth’ method)
By the way, both methods work great.
If you like working with just ONE function, thinking about where it is positive, negative, and zero, then you might prefer the first method.
If you're fine working with TWO functions, thinking about where the graph of one lies on, above, or below the graph of the other, then you might prefer the second method.
## EXAMPLE: solve ‘$\,x^2 \ge 3\,$’ using the one-function (‘compare with zero’) method
YOU WRITE THIS DOWN COMMENTS $x^2 \ge 3$ original sentence $x^2 - 3\ge 0$ rewrite the inequality with zero on the right-hand side; since the inequality symbol is $\,\ge\,$, we need to determine where the graph of $\,x^2 - 3\,$ lies on ($\,=\,$) or above ($\,\gt\,$) the $x$-axis $f(x) := x^2 - 3$ if desired, name the function on the left-hand side $\,f\,$, so it can be easily referred to in later steps; recall that ‘$:=$’ means ‘equals, by definition’ $x^2 - 3 = 0$ $x^2 = 3$ $x = \pm\sqrt 3$ (no breaks in graph of $\,f\,$) identify the candidates for sign changes for $\,f\,$: where $\,f(x)\,$ is zero breaks in the graph of $f$ SIGN OF $\,f(x)\,$ mark the candidates from the previous step on a number line which is labeled ‘SIGN OF $\,f(x)\,$’ mark zeroes with the tick mark ‘$\,z\,$ ’ test each subinterval to see if $\,f(x)\,$ is $\,+\,$ or $\,-\,$; since $\,\sqrt 3\approx 1.7\,$, test points $\,-2\,$ and $\,2\,$ are easy If the graph of $\,f\,$ is easy to obtain, then draw it in; in this case, you don't even need the test points! Graph above the $x$-axis? Then $\,f(x)\,$ is positive. Graph below the $x$-axis? Then $\,f(x)\,$ is negative. In this example, both the test points and graph are shown. solution set: $(-\infty,-\sqrt 3] \cup [\sqrt 3,\infty)$ sentence form of solution: $x\le -\sqrt 3\ \ \text{ or }\ \ x\ge \sqrt 3$ read off the solution set, using correct interval notation; or, give the sentence form of the solution
When a graph is easy to obtain (as in this example), then you may not need to ‘officially’ use the test point method.
Just graph $\,f(x) = x^2 - 3\,$ (see below);
the solutions of ‘$\,x^2 - 3 \ge 0\,$’ are the values of $\,x\,$ for which the graph of $\,f\,$ lies on or above the $x$-axis.
## EXAMPLE: solve ‘$\,x^2 \ge 3\,$’ using the two-function (‘truth’) method
$x^2 \ge 3$ original sentence $f(x) := x^2$, $g(x) := 3$ if desired, define functions $\,f\,$ (the left-hand side) and $\,g\,$ (the right-hand side), so they can be easily referred to in later steps $x^2 = 3$ $x = \pm\sqrt 3$ (no breaks in either graph) find where $\,f(x)\,$ and $\,g(x)\,$ are equal (intersection points); find any breaks in the graphs of $\,f\,$ and $\,g\,$ TRUTH OF ‘$\,x^2 \ge 3\,$’ mark intersection points and breaks on a number line, which is labeled ‘TRUTH OF ‘$\,x^2 \ge 3\,$’ mark intersection points with the tick mark $\,i\,$ using easy test points from each subinterval, check if ‘$\,x^2 \ge 3\,$’ is TRUE or FALSE, and mark accordingly solution set: $(-\infty,-\sqrt 3] \cup [\sqrt 3,\infty)$ sentence form of solution: $x\le -\sqrt 3\ \ \text{ or }\ \ x \ge\sqrt 3$ read off the solution set, using correct interval notation; or, give the sentence form of the solution
When graphs are easy to obtain (as in this example), then you may not need to ‘officially’ use the test point method.
Just graph $\,f(x) = x^2\,$ (in red below) and $\,g(x) = 3\,$ (in green below):
then, the solutions of ‘$\,x^2 \ge 3\,$’ are the values of $\,x\,$ for which the graph of $\,f\,$ lies on or above the graph of $\,g\,$.
## Using WolframAlpha to solve nonlinear inequalities
Just for fun, jump up to wolframalpha.com and key in: x^2 >= 3
Voila!
Master the ideas from this section
The Test Point Method for Sentences like ‘$\,f(x) \gt 0$’
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https://www.cchobby.nl/creatieve-ideeen/creativiteit-met-papier-en-karton/diy-met-faux-leather-papier/mand-van-leerpapier-met-goudfolie-voor-kerst-i
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# Mand van leerpapier met goudfolie voor Kerst
Inspiration: 15000
Van: € 1,69
Tot: € 138,91
Prijs van het idee: € 0,00
Incl. BTW
Van: € 1,69
Tot: € 138,91
Deze mand is gemaakt van leerpapier met aan één kant goudfolie. Engelen en kerstbomen zijn geknipt uit leerpapier en op de mand gelijmd.
Hoe werkt het
Step 1.
Small bag (finished measurements 13x11 cm): cut a piece measuring 37x17 cm. The base is a 12 cm diameter circle. Large bag (finished measurements 20x20 cm): cut a piece measuring 65x28 cm. The base is a 19 cm diameter circle. Moisten the paper in water and scrunch it up for a rustic look.
Step 2.
Sew the cut-out pieces together to make two tubes measuring 17 cm and 28 cm.
Step 3.
Attach the base with pegs and sew it on. Now turn the bag inside out, so that the gold side is on the outside.
Step 4.
Cut out the figures from the template which is available as a separate PDF file for this idea (we will be using the paper side so be careful with pencil lines as these are not easily rubbed out).
Step 5.
Apply glue onto the gold side. Distribute the glue over the entire surface.
Step 6.
Glue the figure onto the bag and attach masking tape, making sure that the entire figure is connected to the bag whilst drying.
Template
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https://svn.haxx.se/subdev/archive-2008-04/0011.shtml
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# Re: [Subclipse-dev] Conflict Subclipse vs. Apache 2.2 libraries crashes Eclipse (3.2/3.3)?
From: Andrew Vaughan <ajv-lists_at_netspace.net.au>
Date: Wed, 9 Apr 2008 11:23:35 +1000
Hi Holger
On Wednesday 09 April 2008 08:26, Holger Stratmann wrote:
> Hello everybody,
>
> I'm currently running Subversion on my local machine and had to upgrade
> to Apache 2.2 yesterday.
> The (subversion) binaries for Apache 2.0 and Apache 2.2 are not
> compatible. I knew that.
> However, to make Apache 2.2 work, the binaries actually have to be in
> the path - which gave me quite a headache yesterday...
>
> Today, I opened one of my Subversion-controlled projects in Eclipse and
> Eclipse crashed and wouldn't even start after that (i.e. crash during
> startup). Same for Eclipse 3.2.
> This also gave me quite a headache because I initially suspected several
> other reasons. After quite some forth and back, I narrowed it down to
> the Subclipse plugin and to the binaries in
> plugins\org.tigris.subversion.javahl.win32_1.2.4 specifically.
>
> When I (re)move this folder OR remove the Subversion 1.4.6 libraries
> from the path, I can use Eclipse.
>
> Even after removing org.tigris.subversion.javahl.win32_1.2.4,
> I still get the decorations and I think Subclipse even works?! (After
> all, org.tigris.subversion.subclipse.core_1.2.4.jar and
> org.tigris.subversion.subclipse.ui_1.2.4.jar are still in my plugins
> directory and the ("other") binaries are still in my path)
>
If subclipse can't find javahl, I think it falls back using svnkit.
> Soo... the first question is: Will Subclipse still work? I now disabled
> it because I wasn't sure.
> And the second question: Why does it crash and what can be done about
> it? I think it's a bug and gave me quite a headache for quite a while!
>
See http://subclipse.tigris.org/faq.html#win32-crash
Cheers
Andrew
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe_at_subclipse.tigris.org
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http://mathhelpforum.com/business-math/63109-dividends.html
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Dividends
1. I am so lost and I do not understand the instructor or the book on this topic..... Here is my question.....
If my total dividend is 5,000.00, the outstanding stock of the company is $10,000 shares of 2% cummulative preferred stock,$100.00 par what is my total preferred dividend and what is my share?
How do I compute this????????
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https://acs.figshare.com/articles/Modeling_Excluded_Volume_Effects_for_the_Faithful_Description_of_the_Background_Signal_in_Double_Electron_Electron_Resonance/2337574/1
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## Modeling Excluded Volume Effects for the Faithful Description of the Background Signal in Double Electron–Electron Resonance
2013-12-27T00:00:00Z (GMT) by
We discuss excluded volume effects on the background signal of double electron–electron resonance (DEER) experiments. Assuming spherically symmetric pervaded volumes, an analytical expression of the background signal is derived based on the shell-factorization approach. The effects of crowding and off-center label positions are discussed. Crowding is taken into account using the Percus–Yevick approximation for the radial distribution function of the particle centers. In addition, a versatile approach relating the pair-correlation function of the particle centers with those of off-center labels is introduced. Limiting expressions applying to short and long dipolar evolution times are derived. Furthermore, we show under which conditions the background with significant excluded volume effects resembles that originating from a fractal dimensionality ranging from 3 to 6. DEER time domain data of spin-probed samples of human serum albumin (HSA) are shown to be strongly affected by excluded-volume effects. The excluded volume is determined from the simultaneous analysis of spectra recorded at various protein concentrations but a constant probe-to-protein ratio. The spin-probes 5-DOXYL-stearic acid (5-DSA) and 16-DOXYL-stearic acid (16-DSA) are used, which, when taken up by HSA, give rise to broad and well-defined distance distributions, respectively. We compare different, model-free approaches of analyzing these data. The most promising results are obtained by the concurrent Tikhonov regularization of all spectra when a common background model is simultaneously adjusted such that the a posteriori probability is maximized. For the samples of 16-DSA in HSA, this is the only approach that allows suppressing a background artifact. We suggest that the delineated simultaneous analysis procedure can be generally applied to reduce ambiguities related to the ill-posed extraction of distance distributions from DEER spectra. This approach is particularly valuable for dipolar signals resulting from broad distance distributions, which as a consequence, are devoid of explicit dipolar oscillations.
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|
https://aviation.stackexchange.com/questions/36781/what-is-the-difference-between-x-and-configuration-in-missiles
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# What is the difference between “x” and “+” configuration in missiles?
What is the difference between "x" and "+" configuration tail fins, and what are the advantages of each in free flight? (for example JDAM missiles)
• The difference is a rotation by 45°. – Peter Kämpf Apr 2 '17 at 11:45
• @PeterKämpf you mean the max rotation of "x" configuration will be 45° ,or max rotation in "+" configuration will be 45° – Michael Apr 3 '17 at 6:19
• @PeterKämpf: Very funny, but you're obviously missing something. The drawings imply that the tail fins operate differently (except for roll) in both configurations, so as to move the missile only in the vertical and horizontal axis in any of the configurations. So the question is valid if these different configurations do indeed exist. OP: Do you have the source where the drawing is taken from? – Scrontch Apr 3 '17 at 15:20
• @Scrontch: Missiles are stabilised by rolling. Yes, the effectiveness of the control surface varies slightly with roll angle, but in reality commands are almost always a mixture of pitch and yaw, and constantly changing due to the rolling motion. This is no either - or situation. – Peter Kämpf Apr 3 '17 at 16:04
• @PeterKämpf: Missiles are stabilised by rolling. Do you have any sources for that? From what i was able to pick up, i conclude this is NOT true. The vast majority of missiles (MANPADS are an exception) are roll-stabilized, i.e. they actively counter-act roll to maintain a fixed longitudinal plane. (Which of course can either be the + or the X plane, with respect to the control fins - which brings us back to the question) cf. maritime.org/doc/missile/part1.htm, section 5A2 books.google.fr/books?id=ubcczZUDCsMC, section 7-2 – Scrontch Apr 4 '17 at 8:39
Mounting missiles below a wing or stocking them in weapon bays is much easier with X-Configured missiles. Look at these photos:
K-5M Missile Source
AIM-120 Missile Source
"+" mounted missiles would need more complex hard points and larger weapon bays.
Once fired the configuration doesn't matter anymore as all four control surfaces are continuously used to guide and stabilize the missile along its 3d trajectory.
If the missile only moves in the horizontal or vertical plane, the X configuration is better. For a fixed force F the angle of attack of the control surfaces ($\alpha_{cs}$) is smaller and can therefore be set faster, making the missile more agile. Assuming* a linear relationship between the the control surface force and its angle of attack:
$$\alpha_{csx} = \frac{F}{q \cdot S \cdot C_{L\alpha}}\cdot \frac{\sqrt{2}}{4}$$ $$\alpha_{cs+} = \frac{F}{q \cdot S \cdot C_{L\alpha}}\cdot \frac{1}{2}$$
For a quadratic relationship* between the drag ($D_{cs}$) and the angle of attack of the control surfaces there is no difference in the total drag.
$$D_{cs+} = q \cdot S \cdot (4\cdot C_{D0}+2 \cdot C_{D\alpha} \alpha_{cs+}^2) = 4\cdot q \cdot S \cdot C_{D0} + \frac{1}{2} C_{D\alpha} \cdot (\frac{F}{q \cdot S \cdot C_{L\alpha}})^2$$
$$D_{csx} = q \cdot S \cdot (4\cdot C_{D0}+4 \cdot C_{D\alpha} \alpha_{csx}^2) = 4\cdot q \cdot S \cdot C_{D0} + \frac{1}{2} C_{D\alpha} \cdot (\frac{F}{q \cdot S \cdot C_{L\alpha}})^2$$
*If someone has better assumptions for lift and drag please comment or correct the post.
• Note that some missiles, such as the AIM-7 Sparrow use the upper fin for mounting. They have moved away from that, though. Maybe due to occurrences like this – TomMcW Apr 2 '17 at 20:55
• @TomMcW I'm loving that link – Pugz Apr 3 '17 at 1:24
• @jwenting i appreciate your help, but which one do you prefer for maneuvering "x" or "+" and why ? – Michael Apr 3 '17 at 7:03
• @jwenting Yes, that's why I wrote that once fired the configuration doesn't matters anymore: it will fly following some 3d-trajectory combining pitch, yaw and roll movements in unknown amounts depending on the target (airplane) and disturbances. – Gypaets Apr 3 '17 at 7:09
• @TomMcW great story on the link! – PJNoes Apr 4 '17 at 17:28
The difference between cross and plus configuration has nothing to do with equations of motion. The difference is just in control system implementation and transferring the control surface deflections to equivalent 3 plane surfaces. for example cross config can be controlled better, while plus config in simpler. or: for optimum control efort for a specified da dr de: in plus: d1= da-dr in cross:d1=da+de-dr
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http://www.reference.com/browse/balmer-series
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Definitions
# Balmer series
[bahl-mer]
The Balmer series or Balmer lines in atomic physics, is the designation of one of a set of six different named series describing the spectral line emissions of the hydrogen atom.
The Balmer series is calculated using the Balmer formula, an empirical equation discovered by Johann Balmer in 1885. The visible spectrum of light from hydrogen displays four wavelengths, 410 nm, 434 nm, 486 nm, and 656 nm, that reflect emissions of photons by electrons in excited states transitioning to the quantum level described by the principal quantum number n equals 2.
## Overview
The Balmer series is characterized by the electron transitioning from n ≥ 3 to n = 2, where n refers to the radial quantum number or principal quantum number of the electron. The transitions are named sequentially by Greek letter: n = 3 to n = 2 is called H-α, 4 to 2 is H-β, 5 to 2 is H-γ, and 6 to 2 is H-δ. As the first spectral lines associated with this series are located in the visible part of the electromagnetic spectrum, these lines are historically referred to as "H-alpha", "H-beta", "H-gamma" and so on, where H is the element hydrogen.
Transition of $n$ Name Wavelength (nm) Color 3→2 4→2 5→2 6→2 7→2 8→2 9→2 $infty$→2 H-α H-β H-γ H-δ H-ε H-ζ H-η 656.3 486.1 434.1 410.2 397.0 388.9 383.5 364.6 Red Blue-green Violet Violet Violet Violet (Ultraviolet) (Ultraviolet)
Although physicists were aware of atomic emissions before 1885, they lacked a tool to accurately predict where the spectral lines should appear. The Balmer equation predicts the four visible absorption/emission lines of hydrogen with high accuracy. Balmer's equation inspired the Rydberg equation as a generalization of it, and this in turn led physicists to find the Lyman, Paschen, and Brackett series which predicted other absorption/emission lines of hydrogen found outside the visible spectrum.
The familiar red H-alpha spectral line of hydrogen gas, which is the transition from the shell n = 3 to the Balmer series shell n = 2, is one of the conspicuous colors of the universe. It contributes a bright red line to the spectra of emission or ionization nebula, like the Orion Nebula, which are often H II regions found in star forming regions. In true-color pictures, these nebula have a distinctly pink color from the combination of visible Balmer lines that hydrogen emits.
Later, it was discovered that when the spectral lines of the hydrogen spectrum are examined at very high resolution, they are found to be closely-spaced doublets. This splitting is called fine structure. It was also found that excited electrons could jump to the Balmer series n=2 from orbitals where n was greater than 6, emitting shades of violet when doing so.
## Balmer's formula
Balmer noticed that a single number had a relation to every line in the hydrogen spectrum that was in the visible light region. That number was 364.56 nm. When any integer higher than 2 was squared and then divided by itself minus 4, then that number multiplied by 364.56 gave a wavelength of another line in the visible hydrogen spectrum. By this formula he was able to show that certain measurements of lines made in his time by spectroscopy were slightly inaccurate measurements and his formula predicted lines that were later found although had not yet been observed. His number also proved to be the limit of the series.
The Balmer equation could be used to find the wavelength of the absorption/emission lines and was originally presented as follows (save for a notation change to give Balmer's constant as B):
$lambda = Bleft\left(frac\left\{m^2\right\}\left\{m^2 - n^2\right\}right\right) = Bleft\left(frac\left\{m^2\right\}\left\{m^2 - 2^2\right\}right\right)$
Where
$lambda$ is the wavelength.
B is a constant with the value of 3.6456×10-7 m or 364.56 nm.
n is equal to 2
m is an integer such that m > n.
In 1888 the physicist Johannes Rydberg generalized the Balmer equation for all transitions of hydrogen. The equation commonly used to calculate the Balmer series is a specific example of the Rydberg formula and follows as a simple reciprocal mathematical rearrangement of the formula above (conventionally using a notation of n for m as the single integral constant needed):
$frac\left\{1\right\}\left\{lambda\right\} = frac\left\{4\right\}\left\{B\right\}left\left(frac\left\{1\right\}\left\{2^2\right\} - frac\left\{1\right\}\left\{n^2\right\}right\right) = R_mathrm\left\{H\right\}left\left(frac\left\{1\right\}\left\{2^2\right\} - frac\left\{1\right\}\left\{n^2\right\}right\right), n=3,4,5,...$
where λ is the wavelength of the absorbed/emitted light and RH is the Rydberg constant for hydrogen. The Rydberg constant is seen to be equal to 4/B in Balmer's formula, and for an infinitely heavy nucleus is 4/(3.6456*10-7m) = 10,973,731.57 m−1.
## Role in astronomy
The Balmer series is particularly useful in astronomy because the Balmer lines appear in numerous stellar objects due to the abundance of hydrogen in the universe, and therefore are commonly seen and relatively strong compared to lines from other elements.
The spectral classification of stars, which is primarily a determination of surface temperature, is based on the relative strength of spectral lines, and the Balmer series in particular are very important. Other characteristics of a star can be determined by close analysis of its spectrum include surface gravity (related to physical size) and composition.
Because the Balmer lines are commonly seen in the spectra of various objects, they are often used to determine radial velocities due to doppler shifting of the Balmer lines. This has important uses all over astronomy, from detecting binary stars, exoplanets, compact objects such as neutron stars and black holes (by the motion of hydrogen in accretion disks around them), identifying groups of objects with similar motions and presumably origins (moving groups, star clusters, galaxy clusters, and debris from collisions), determining distances (actually redshifts) of galaxies or quasars, and identifying unfamiliar objects by analysis of their spectrum.
Balmer lines can appear as absorption or emission lines in a spectrum, depending on the nature of the object observed. In stars, the Balmer lines are usually seen in absorption, and they are "strongest" in stars with a surface temperature of about 10,000 kelvin (spectral type A). In the spectra of most spiral and irregular galaxies, AGNs, H II regions and planetary nebulae, the Balmer lines are emission lines.
In stellar spectra, the H-epsilon line (transition 7-2) is often mixed in with another absorption line caused by ionized calcium known by astronomers as "H" (the original designation given by Fraunhofer). That is, H-epsilon's wavelength is quite close to CaH at 396.847nm, and cannot be resolved in low resolution spectra. The H-zeta line (transition 8-2) is similarly mixed in with a neutral helium line seen in hot stars.
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http://mathhelpforum.com/advanced-statistics/226892-microstates.html
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# Math Help - microstates
1. ## microstates
when you flip a coin 50 times, the total number of microstates is 250. How can you show this by using the binomial theoreom. Thank you!
2. ## Re: microstates
Originally Posted by apatite
when you flip a coin 50 times, the total number of microstates is 250. How can you show this by using the binomial theoreom.
${2^{50}} = {\left( {1 + 1} \right)^{50}} = \sum\limits_{k = 0}^{50} {\left( {\begin{array}{*{20}{c}} {50} \\ k \end{array}} \right)}$
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|
http://mathematica.stackexchange.com/questions/17196/order-of-integration-changes-output-of-indefinite-multiple-integral-in-mathemati/17197
|
# Order of integration changes output of indefinite multiple integral in Mathematica 7
I'm trying to integrate a form-factor used in the calculation of radiation between two rectangles in perpendicular planes. While the integral is usually done over fixed limits, I am trying to do the indefinite multiple integral. When I change the order of integration the results differ in one term.
Because the result gets used in a summation that is essentially evaluating the integral at the end points representing the rectangle limits, the extra terms do not matter i.e. they end up cancelling out. But I'm bothered that they are being generated to begin with and that they differ when I change the order of integration.
In order to make sure that the difference is not because of the possibility of imaginary numbers or zeros, cropping up, I set assumptions that limit the variables to all be finite positive numbers. I'm guessing the differences are because of the log's or arctan's that crop up during the integration, but I can't figure out why.
In the example below the two integrals differ in the term x^2 , 2yw-y^2
The effects are not from FullSimplify as that just collects terms - it doesn't combine log or arctan terms.
Can anyone explain the results I get? I'm running Mathematica 7.0 Thanks in advance! (sorry I can't post an image but I'm a new user so it's not allowed)
Fperp = FullSimplify[
1/Pi Integrate[(x*z)/(x^2 + z^2 + (y - w)^2)^2, x, y, z, w,
Assumptions -> {x > 0 && w > y0 & z > 0 && y > 0 &&
x <= Infinity && y < Infinity && z < Infinity &&
w < Infinity}]]
(* ===> (x^2 + 4 (w - y) Sqrt[x^2 + z^2]
ArcTan[(w - y)/Sqrt[x^2 + z^2]] + (-x^2 + (w - y)^2 - z^2) Log[
x^2 + (w - y)^2 + z^2])/(8 \[Pi]) *)
Fperp2 = FullSimplify[(1/Pi)*
Integrate[(x*z)/(x^2 + z^2 + (y - w)^2)^2, w, z, y, x,
Assumptions -> {x > 0 && w > 0 && z > 0 && y > 0 &&
x < Infinity && y < Infinity && z < Infinity && w < Infinity}]]
(* ===> (-w (w - 2 y) + 4 (w - y) Sqrt[x^2 + z^2]
ArcTan[(w - y)/Sqrt[x^2 + z^2]] + (-x^2 + (w - y)^2 - z^2) Log[
x^2 + (w - y)^2 + z^2])/(8 \[Pi]) *)
-
D[Fperp, x, y, z, w] == D[Fperp2, x, y, z, w]
|
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https://iwaponline.com/washdev/article/7/2/260/30237/Types-and-distribution-of-improved-sanitation
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Access to improved sanitation technologies in sub-Saharan Africa (SSA) is very low. Despite the importance of improved sanitation technologies in sanitation monitoring, little attention has been given towards the types and distributions of improved sanitation technologies used in SSA. This paper presents an analysis of the distribution of improved sanitation technologies in SSA, with particular emphasis on factors influencing their distribution. Study data were derived from demographic health surveys, multiple indicator cluster surveys and World Bank Development Indicators. Results showed that the pit latrine with slab was the most prevalent technology (21%), while the composting toilet had the least coverage (0.6%). Multiple regression analysis results showed positive significant relationships between the following: income and flush toilets connected to sewer (p = 0.000), urban population and flush toilets connected to septic tanks (p = 0.000), development assistance and pit latrine with slab (p = 0.035) and a negative relationship between population and flush toilets connected to pit latrines (p = 0.030). The paper concluded that selection of sanitation technologies is influenced by different factors. In addition, prevailing socio-economic conditions can result in selection of inappropriate technologies. Technology selection, however, should strive to strike a balance between the economic, environmental, human health and socio-cultural sustainability aspects of sanitation.
## INTRODUCTION
Access to improved sanitation technologies in sub-Saharan Africa (SSA) is very low. Improved sanitation technologies refer to technologies which can hygienically separate human excreta from human contact (WHO/UNICEF 2015). These include: composting toilets, pit latrine with slab, ventilated improved pit (VIP) latrines, flush/pour-flush toilets connected to either pit latrines, septic tanks or piped sewer (WHO/UNICEF 2015). By the end of the millennium development goals period in 2015, only 30% of the SSA population had access to improved sanitation technologies (WHO/UNICEF 2015).
It seems that the composting toilet has not been widely accepted in SSA despite the attached economic and environmental benefits such as high potential for nutrient and energy recovery and reductions in water use and wastewater treatment costs (Hill & Baldwin 2012; Anand & Apul 2014). One reason for the low adoption of the composting toilet is that traditionally people in SSA do not use human faeces as a soil conditioner in agriculture (Dellstro & Rosenquist 2005; WSP 2005), unlike in other regions such as Asia where countries like China have been using human excreta as a soil conditioner for a long time (Winblad & Simpson-Hebert 2004; Dellstro & Rosenquist 2005). The uptake of composting toilets, especially in urban areas in SSA, may also be hampered by a lack of awareness, and by policies and regulations and a lack of knowledge and skills in designing and operating the toilets (Anand & Apul 2014).
In contrast, the pit latrine with slab is the most prevalent sanitation technology in SSA (Katukiza et al. 2012; Nakagiri et al. 2016). This could be attributed to the technology's low capital and operation and maintenance (O&M) costs, ease of O&M, simplicity and non-usage of water (WHO/UNICEF 2000; Flores et al. 2009; Nakagiri et al. 2016). The pit latrine with slab, however, can pose risks of groundwater contamination and disease transmission and can have problems of flies and odour (Dzwairo et al. 2006; Nakagiri et al. 2016).
On the other hand, the flush/pour-flush toilet is more expensive and more advanced than the other improved sanitation technologies and requires water to operate (WHO/UNICEF 2000; Murray et al. 2009), which could explain its low coverage in SSA (Nakagiri et al. 2016). However, despite its high costs, several authors have reported that the flush toilet has higher health benefits compared to other improved sanitation technologies (Morella et al. 2008; Günther & Fink 2010, 2011). Research has also shown that flush toilets can greatly reduce the probability of children under-5 suffering from diarrhoeal diseases and that they can reduce child mortality compared to improved pit latrines (Günther & Fink 2010, 2011). This, however, does not mean that the flush toilet is the best sanitation option, as it may fail to provide public health protection in other sections of the sanitation service chain, e.g. transportation or treatment of wastewater. Several authors have reported that most of the wastewater in SSA is discharged untreated into the environment thus posing a serious public health risk (Baum et al. 2013; Sato et al. 2013). In contrast, onsite sanitation technologies like the VIP latrine and septic tanks, which can be more affordable compared to sewered flush toilets (Dodane et al. 2012), can provide better public health protection when properly maintained (Morella et al. 2008; Günther & Fink 2010). However, faecal sludge collected from onsite technologies in urban areas of SSA is largely discharged untreated into the environment, thereby compromising public health (Peal et al. 2014; Strande et al. 2014).
In monitoring access to sanitation, the Joint Monitoring Programme for Water Supply and Sanitation (JMP) of the World Health Organization and the United Nations Children's Fund (UNICEF) assesses usage of improved sanitation technologies. The format used by JMP to report global and country sanitation coverage shows statistics disaggregated into improved, shared, other unimproved sanitation facilities and open defaecation. However, the improved sanitation technologies which contribute towards the improved sanitation access are not shown in the JMP reports. Thus, this makes it difficult to understand the impact of technology choice on sanitation coverage and, by extension, sanitation success.
In order to improve the understanding of the relationship between improved sanitation technologies and sanitation success within a given SSA country, the distributions of the improved sanitation technologies must be known. This information seems to be currently lacking. Earlier work by Morella et al. (2008) failed to capture the distributions of the different technologies. For example, pit latrine with slab and VIP latrines were grouped as improved latrines, making it impossible to decipher the separate coverage of the two technologies. Furthermore, in a more recent study by Nakagiri et al. (2016), statistics for the pit latrine with slab, VIP latrines and pour-flush toilets for the national coverage were also grouped together although they were presented separately for urban areas. Similar to the study by Morella et al. (2008), Nakagiri et al. (2016) did not show the coverage for the separate flush toilet connections.
In addition, there seems to be a lack of information on the factors influencing the distribution of sanitation technologies in SSA. Previous studies by Morella et al. (2008) attempted to analyse the factors which influence access to different sanitation technologies in SSA. Some of the suggested factors were income and population densities. However, the study was rather qualitative and failed to bring out the actual relationships between sanitation technologies and the suggested factors. Other studies have also suggested a number of factors that influence technology selection (Mara et al. 2007; Murphy et al. 2009; Malekpour et al. 2013). In these studies, the factors cited can be classified as economic, environmental, health, institutional, socio-cultural and technical. The current study builds on and improves on the previous studies on improved sanitation technologies in SSA. The objectives of the present study were: (i) to assess the distributions of the improved sanitation technologies used in SSA countries; and (ii) to investigate the factors which affect technology distribution/selection in SSA.
## METHODS
### Description of the study area
SSA comprises 52 African countries and island states and excludes the northern African countries: Algeria, Egypt, Libya, Morocco, Tunisia and Western Sahara (UN 2013; PRB 2014). The population of SSA is approximately 1 billion (UN 2015). The majority of the population of SSA lives in rural areas (63%) while only 37% live in urban areas (PRB 2014). Annual population growth rate averages 2.7%, which is higher than the average growth rate for Africa of 2.5% (UN 2015).
The economies of SSA countries have been growing strongly since the mid-1990s (IMF 2013) with some of the world's fastest growing economies (on the basis of gross domestic product, GDP) found in the region. The economic growth of the region, however, slowed down in 2015, largely because of the falling prices of oil and other commodities (World Bank 2015). The decline in economic growth coupled with the large number of low-income countries, could have a bearing on the selection of sanitation technologies (Morella et al. 2008; Murphy et al. 2009).
### Selection of variables
The independent variables were chosen based on their likely influence on technology selection as informed by previous studies. Previously studied factors include: population, population density, urban population, water use and water availability, social acceptance of the technology, policy, land requirements, experience and knowledge, protection of human health and environment, investment costs, technology resilience, soil type in settlement area and recycling of nutrients (Mara et al. 2007; Mels et al. 2007; Murphy et al. 2009; Malekpour et al. 2013). In the current study, six independent variables were identified and used: population, population density, urban population, renewable freshwater availability, GDP and development assistance (Table 1). Other variables such as religion, culture, policy and soil type were not included in the analysis either because of lack of data or the complexity of using them in such an analysis.
Table 1
Variables used in analysis and justification
Variable nameUnitsJustificationSource
Population numbers Population increases can pose capacity challenges on selection of sanitation technologies. Thus, countries might be forced to select technologies which might not be appropriate (Murphy et al. 2009). UN (2015)
Population density people per km2 of land area Research shows that land availability may influence technology selection (Nelson & Murray 2008; Flores et al. 2009). Where land is not a problem, such as in low-density areas, on-site sanitation options (e.g. septic tanks and VIP latrines) may be selected. However, in high density areas, off-site sanitation technologies (e.g. flush toilets connected to sewer) may be considered appropriate (Morella et al. 2008). UN (2015)
Urban population % of total population Urbanization generates economies of scale, which reduces units costs of sewerage systems (Arimah 2005; Krause 2008) thereby positively influencing their selection. Urbanization can also negatively impact on technology selection, because of capacity and resource constraints resulting in the selection of inappropriate technologies (Murphy et al. 2009). UN (2014)
GDP US$per capita Research shows that affordable sanitation technologies are most appropriate and most likely to be selected (Mara et al. 2007; Murphy et al. 2009). GDP, which measures the level of economic development of a country, is an indication of a country's capacity to invest in a particular technology. It is expected that countries with high economic growth will select more advanced, expensive sanitation technologies and vice versa (Rudra 2011; Frone & Frone 2014). World Bank (2016) Development assistance US$ Development assistance is an important source of external financing for sanitation infrastructure in many countries (Sachs 2005; UN-Water 2014). It reflects the country's capacity to invest in a specific technology. However, it can be argued that aid conditions and use of aid can also influence technology selection. World Bank (2016)
Renewable freshwater availability m3 per capita per year The type of sanitation technology selected can be greatly influenced by its water usage and water availability (Mels et al. 2007; Flores et al. 2009). Where water supply is limited, it is expected that dry technologies will be the technology of choice, while wet technologies could be preferred in countries with no water supply challenges. FAO (2016)
Variable nameUnitsJustificationSource
Population numbers Population increases can pose capacity challenges on selection of sanitation technologies. Thus, countries might be forced to select technologies which might not be appropriate (Murphy et al. 2009). UN (2015)
Population density people per km2 of land area Research shows that land availability may influence technology selection (Nelson & Murray 2008; Flores et al. 2009). Where land is not a problem, such as in low-density areas, on-site sanitation options (e.g. septic tanks and VIP latrines) may be selected. However, in high density areas, off-site sanitation technologies (e.g. flush toilets connected to sewer) may be considered appropriate (Morella et al. 2008). UN (2015)
Urban population % of total population Urbanization generates economies of scale, which reduces units costs of sewerage systems (Arimah 2005; Krause 2008) thereby positively influencing their selection. Urbanization can also negatively impact on technology selection, because of capacity and resource constraints resulting in the selection of inappropriate technologies (Murphy et al. 2009). UN (2014)
GDP US$per capita Research shows that affordable sanitation technologies are most appropriate and most likely to be selected (Mara et al. 2007; Murphy et al. 2009). GDP, which measures the level of economic development of a country, is an indication of a country's capacity to invest in a particular technology. It is expected that countries with high economic growth will select more advanced, expensive sanitation technologies and vice versa (Rudra 2011; Frone & Frone 2014). World Bank (2016) Development assistance US$ Development assistance is an important source of external financing for sanitation infrastructure in many countries (Sachs 2005; UN-Water 2014). It reflects the country's capacity to invest in a specific technology. However, it can be argued that aid conditions and use of aid can also influence technology selection. World Bank (2016)
Renewable freshwater availability m3 per capita per year The type of sanitation technology selected can be greatly influenced by its water usage and water availability (Mels et al. 2007; Flores et al. 2009). Where water supply is limited, it is expected that dry technologies will be the technology of choice, while wet technologies could be preferred in countries with no water supply challenges. FAO (2016)
### Data and data sources
Data on the types and distributions of improved sanitation technologies within the 48 SSA countries analysed were derived from the most recent surveys on the demographic and health surveys (DHS) database (USAID 2015), multiple indicator cluster survey (MICS) database (UNICEF 2015) and the JMP country files (WHO/UNICEF 2016). The data used were from the year 2008 to 2014. The selection of countries for analysis was guided by the availability of data for the variables used in the regressions. Data on independent variables were taken mainly from World Development Indicators (World Bank 2016) and from the Food and Agriculture Organization of the United Nations (FAO)'s AQUASTAT main database (FAO 2016). The DHS and MICS are nationally representative household surveys which collect information on household characteristics, including access to sanitation. The JMP country files report processed data from different DHS and MICS surveys.
It is worth noting that countries sometimes have different definitions for improved sanitation facilities (UN-Water 2012), with some countries regarding a portion of their traditional pit latrines as improved latrines, as reflected in the respective JMP country files. Other countries such as Angola include shared facilities in their definition of improved sanitation facilities (UN-Water 2012). However, in this study, all traditional latrines and shared facilities were treated as unimproved. This was done to avoid the overestimation of sanitation technologies and to improve the comparability between countries. In cases where a distinction was not made for shared technologies, all the sanitation technologies were assumed to be private.
### Statistical analysis
The data were analysed in two separate stages. Firstly, in order to get the distributions of the various sanitation technologies, the frequencies of each named sanitation technology in the individual SSA countries were calculated using a program constructed in Python software (version 2.6). The sanitation technology data were first weighted using household sampling weights in accordance with the DHS method (Rutstein & Rojas 2006). Weighting was done to produce proper representation of the sample by adjusting for differences in the probability of sample selection and interview cases introduced either by sample design to expand the number of available cases or by chance. Descriptive statistics for each country were generated in Statistical Package for Social Scientists (SPSS) version 20 using cross tabulation. Secondly, to establish factors which affect technology selection, a step-wise multiple regression analysis was performed in SPSS. The analysis was done in six separate equations, equivalent to the six dependent variables used: composting toilet, pit latrines with slab, VIP latrine, flush/pour flush toilet connected to pit latrine, flush/pour flush toilet connected to septic tank and flush/pour flush toilet connected to piped sewer. The variables were entered and removed from the models based on p-values of 0.05. The multiple regression equation used is:
1
where DV is the dependent variable of interest, representing the different sanitation technologies, β0 is the intercept; β1 to βj are the regression coefficients for the independent variables X1 to Xj and i represents the individual countries.
## RESULTS
### Variation of improved sanitation technologies used in SSA and technology selection variables
Table 2 shows the descriptive statistics of the variables used in the analysis. Results showed that there is a wide variation in the distribution of improved sanitation technologies in SSA. The minimum for all technologies is 0%. The pit latrine with slab was shown to be the most prevalent technology with a mean coverage of 21%. It was followed by the flush/pour flush toilet connected to septic tank whose coverage was 14%. The composting toilet seems to be the least used sanitation technology with a mean coverage of 0.6%. Huge differences were also observed for other variables. For example, renewable freshwater availability ranged from a minimum of 103 m3 per capita per year to a maximum of 98,000 m3 per capita per year with an average of 9,000 m3 per capita per year. The GDP ranged from US$175 per capita to US$9,400 per capita with a mean of US$1,500 per capita while the average population was 14,933,000 (range 84,400–135,789,000). Table 2 Descriptive statistics for sanitation technologies and technology selection variables (N = 46) VariablesUnitsMinimumMaximumMean ± std deviation Composting toilet 1 ± 2 Pit latrine with slab 83 21 ± 18 VIP latrine 32 7 ± 9 Flush/pour flush toilet connected to pit latrine 66 5 ± 12 Flush/pour flush toilet connected to septic tank 85 14 ± 18 Flush/pour flush toilet connected to piped sewer 73 11 ± 16 Population numbers 84,400 135,789,000 14,933,000 ± 23,702,000 Population density people per km2 of land area 608 84 ± 113 Urban population 84 38 ± 17 GDP US$ per capita 175 9, 400 1,500 ± 2,100
Development assistance US$378,000 125,113,000 27,582,000 ± 29,700,000 Renewable freshwater availability m3 per capita per year 103 98, 000 9,000 ± 18,000 VariablesUnitsMinimumMaximumMean ± std deviation Composting toilet 1 ± 2 Pit latrine with slab 83 21 ± 18 VIP latrine 32 7 ± 9 Flush/pour flush toilet connected to pit latrine 66 5 ± 12 Flush/pour flush toilet connected to septic tank 85 14 ± 18 Flush/pour flush toilet connected to piped sewer 73 11 ± 16 Population numbers 84,400 135,789,000 14,933,000 ± 23,702,000 Population density people per km2 of land area 608 84 ± 113 Urban population 84 38 ± 17 GDP US$ per capita 175 9, 400 1,500 ± 2,100
Development assistance US$378,000 125,113,000 27,582,000 ± 29,700,000 Renewable freshwater availability m3 per capita per year 103 98, 000 9,000 ± 18,000 ### Distribution of improved sanitation technologies according to type #### Composting toilet The composting toilet is not widely used in SSA as evidenced by more than half of SSA countries (54%) which do not use the technology. Among the countries which use this sanitation technology, the highest coverage was found in Ethiopia (8%), followed by Chad (5%) and Lesotho (4%). #### Pit latrine with slab The highest pit latrine with slab coverage was found in Burkina Faso (83%), Rwanda (61%) and The Gambia (56%) while the lowest coverage was observed in Seychelles (0.7%) (Figure 1). It is also worth noting that some countries such as Cape Verde, Equatorial-Guinea, Eritrea, Guinea-Bissau, Mauritius, Sao Tome and Principe, and Reunion seem not to use the pit latrine with slab. Figure 1 Distribution of pit latrines with slab in SSA. Figure 1 Distribution of pit latrines with slab in SSA. #### VIP latrine The highest VIP latrine coverage was found in Botswana (32%), Nigeria (31%) and Zimbabwe (30%) (Figure 2). It is instructive to note that the island states of Cape Verde, Mauritius, Seychelles and Reunion do not use the VIP latrine. Figure 2 Distribution of VIP latrines in SSA. Figure 2 Distribution of VIP latrines in SSA. #### Flush/pour flush toilet connected to pit latrine The usage of flush/pour flush toilets connected to pit latrine in SSA is very low (5%). However, a total of seven countries had coverage which was above the SSA average while nine countries seem not to use this sanitation technology. The highest usage of the technology was found in Mauritius (66%) and Sao Tome and Principe (39%) (Figure 3). Figure 3 Coverage of flush/pour flush toilets connected to pit latrines in SSA. Figure 3 Coverage of flush/pour flush toilets connected to pit latrines in SSA. #### Flush/pour flush toilet connected to septic tank Liberia and the island states of Reunion, Seychelles and Cape Verde had the highest coverage of flush/pour flush toilets connected to septic tanks. Reunion had 85% while Seychelles and Cape Verde had 52% coverage each. The lowest coverage for the same technology was found in Central African Republic (0.1%) and South Sudan (0.2%) (Figure 4). In countries such as Gabon, Mozambique and Uganda, flush/pour flush toilets connected to septic tanks are almost non-existent. Figure 4 Coverage of flush/pour flush toilets connected to septic tanks in SSA. Figure 4 Coverage of flush/pour flush toilets connected to septic tanks in SSA. #### Flush/pour flush toilet connected to piped sewer The highest coverage of flush/pour flush toilets connected to piped sewer in SSA was found in Namibia (73%), South Africa (66%) and Gabon (55%) (Figure 5). In other countries such as Mozambique, Sao Tome and Principe, and Rwanda, the flush/pour flush toilets connected to piped sewer are virtually non-existent. Figure 5 Coverage of flush/pour flush toilets connected to piped sewer in SSA. Figure 5 Coverage of flush/pour flush toilets connected to piped sewer in SSA. ### Factors affecting distribution of improved sanitation technologies in SSA Table 3 presents the results of the step-wise regression analysis performed to establish the factors which affect the distribution of sanitation technologies. Table 3 Results of multiple regression analysis to determine factors affecting distribution of sanitation technologies in SSA Dependent variables Pit latrine with slabFlush/pour flush toilet connected to pit latrineFlush/pour flush toilet connected to septic tankFlush/pour flush toilet connected to piped sewer Independent variablesUnits Population numbers *** −0.331 (−2.249) 0.030 *** *** Population density people per km2 of land area *** *** 0.393 (3.068) 0.004 *** Urban population % of total population *** *** 0.570 (4.446) 0.000 *** GDP US$ per capita *** *** *** 0.584
(4.771)
0.000
Development assistance US$per capita 0.312 (2.180) 0.035 *** *** *** Constant −43.540 (−1.460) 0.0151 41.732 (2.563) 0.014 −81.159 (−4.446) 0.000 −50.054 (−3.890) 0.000 46 46 46 46 4.752 5.058 11.627 22.761 R2 0.3 0.3 0.6 0.6 0.035 0.030 0.000 0.000 Dependent variables Pit latrine with slabFlush/pour flush toilet connected to pit latrineFlush/pour flush toilet connected to septic tankFlush/pour flush toilet connected to piped sewer Independent variablesUnits Population numbers *** −0.331 (−2.249) 0.030 *** *** Population density people per km2 of land area *** *** 0.393 (3.068) 0.004 *** Urban population % of total population *** *** 0.570 (4.446) 0.000 *** GDP US$ per capita *** *** *** 0.584
(4.771)
0.000
Development assistance US\$ per capita 0.312
(2.180)
0.035
*** *** ***
Constant −43.540
(−1.460)
0.0151
41.732
(2.563)
0.014
−81.159
(−4.446)
0.000
−50.054
(−3.890)
0.000
46 46 46 46
4.752 5.058 11.627 22.761
R2 0.3 0.3 0.6 0.6
0.035 0.030 0.000 0.000
The figures in cells are: regression coefficient (b); t-statistic; p-value (p < 0.05); *** indicates non-significant relationships (p > 0.05).
N = sample size; F = F-statistic; R2 = coefficient of determination.
The analysis produced four regression models which were statistically significant (all p-values ≤ 0.035) whose coefficients of determination, R2, varied from 0.3 to 0.6. The significant models were the pit latrine with slab, flush/pour flush toilet connected to pit latrine, flush/pour flush toilet connected to septic tank and flush/pour flush toilet connected to piped sewer. The VIP latrine and composting toilet models were not significant.
The pit latrine with slab model showed the pit latrine with slab to be significantly associated with development assistance (p = 0.035). In addition, a significant negative relationship was found between flush/pour flush toilet connected to pit latrine and population (p = 0.030). For the flush/pour flush toilet connected to septic tank model, urban population (p = 0.000) and population density (0.004) had a positive significant relationship with flush/pour flush toilet connected to septic tanks. In the flush/pour flush toilet connected to piped sewer model, GDP showed a positive significant relationship with flush/pour flush toilet connected to piped sewer (p = 0.000).
## DISCUSSION
### Distribution of improved sanitation technologies
This study demonstrates that in SSA, the improved sanitation technology with the highest coverage was the pit latrine with slab while the composting toilet had the lowest coverage. This observation is supported by earlier studies, which attributed the high usage of the pit latrine with slab to low capital and O&M costs, simplicity and non-water usage (Flores et al. 2009; Nakagiri et al. 2016) relative to other technologies, which tend to be more expensive (e.g. VIP and flush toilets) and require water for operation (e.g. flush toilets). On the other hand, the low usage of composting toilet could be influenced by the faecophobic culture prevalent in most parts of SSA (Dellstro & Rosenquist 2005).
The distribution of improved sanitation technologies for SSA, however, mask the variations across countries. For example, it was shown that some countries had pit latrine with slab coverage as high as 83% whereas other countries had coverage as low as 0.7% for the same technology. These results are a reflection of the variability in the socio-economic and environmental conditions of SSA countries which tend to influence technology selection and use.
### Factors affecting distribution of improved sanitation technologies
Results of multiple regression analysis performed to investigate the factors which affect the distribution of improved sanitation technologies in SSA showed a positive significant relationship between pit latrine with slab and development assistance, suggesting that countries which received higher aid tend to install the pit latrine with slab over other technologies. While reasons for such choices might not be clear, it is assumed that when the aid is disbursed, it will have conditions on how it is supposed to be used, including installation of the cheapest technology in order to rapidly increase coverage. Alternatively, it could be the aid recipients themselves who may target a particular technology over other sanitation technologies.
On the other hand, the present study found a negative association between flush/pour flush toilet connected to pit latrine and population, suggesting that countries with high populations were most unlikely to select the flush/pour flush toilet connected to pit latrine. This is probably because when the population increases, population density will also likely increase, making it infeasible to install this type of technology as it will be difficult to empty, close the pit or dig another one because of space constraints (Satterthwaite et al. 2015).
The distribution of the flush/pour flush toilet connected to septic tank was found to be positively associated with urban population and population density. The association of the flush/pour flush connected to septic tank and urban population suggests that countries tend to select this technology when urban population increases. The positive association between urban population and flush/pour flush toilet connected to septic tank could be attributed to the capacity challenges faced by local authorities to extend sewerage connections to the unserved populations (McGranahan 2015), as sewerage is a technology of choice for most urban areas (Paterson et al. 2007). The sewerage network capacity challenges then force households to provide their own sanitation services, which results in the proliferation of septic tanks installed by households.
A positive association, which was found between population density and flush/pour flush toilet connected to septic tank, was not consistent with expectations. It would have been expected that local authorities would take advantage of economies of scale to install technologies such as the flush/pour flush toilet connected to piped sewer, where unit costs decrease with population (Krause 2008). Nonetheless, sometimes because of population growth in urban areas, the authorities fail to provide services, as explained above, leading to households installing septic tanks even in high density areas where the stand sizes might be below the minimum standard sizes required to install septic tanks (Ngwenya 2013).
The study also found a positive relationship between flush/pour flush toilet connected to piped sewer and GDP. This association suggests that countries with higher income have higher coverage of the flush/pour flush toilet connected to piped sewer technology, which is more advanced and more expensive compared to other sanitation technologies. These results are consistent with earlier studies which found a relationship between high economic development and the presence of advanced sanitation technology (Rudra 2011; Frone & Frone 2014).
The lack of association between VIP and composting toilet with any of the independent variables suggests that the other factors which were not investigated could have influenced the selection of these technologies in countries where they have high coverage. Factors such as policy, culture, protection of health, and recycling and reuse of nutrients could have played a major role in the selection of sanitation technologies (Mara et al. 2007; Malekpour et al. 2013).
## CONCLUSIONS AND RECOMMENDATIONS
The study analysed the types and distributions of improved sanitation technologies used in SSA and the factors influencing their distribution. The need to understand the distribution of improved sanitation technologies is based on the realization that such information is currently not readily available yet it could help to explain the differences in sanitation success observed in the SSA region.
The study demonstrated that the distribution of improved sanitation technologies varies widely within and across SSA countries. While some countries had coverage of all the improved sanitation technologies specified in the sanitation ladder, in other countries some technologies were almost non-existent. From this study, it was concluded that the technologies used in SSA were influenced by certain criteria. The factors influencing distribution of technologies included income, population, population density, urban population and development assistance. It is imperative to note that sometimes countries select inappropriate sanitation technologies because of unfavourable socio-economic conditions.
Due to data limitations, the study, however, could not investigate the influence of other factors which have previously been suggested to influence technology selection. These factors include: policies, culture, technology resilience, knowledge, skills and experience, and the recycling and reuse of nutrients. In order to improve the understanding of factors affecting technology selection in SSA, there is a need to carry out further investigations on the influence of these factors. While technology selection in SSA was shown to be influenced by a number of factors, it is important to strike a balance between the economic, environmental, human health and socio-cultural sustainability aspects of sanitation.
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https://www.physicsforums.com/threads/linear-space.3567/
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Linear space
1. Jul 3, 2003
meteor
Is the same thing a linear space and a vector space?
2. Jul 3, 2003
Tyger
And often refered to
as a linear vector space. Although linear is more often applied to operators in a space.
3. Jul 3, 2003
lethe
yes. same thing.
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https://brilliant.org/problems/testing-buridan/
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Testing Buridan
Discrete Mathematics Level pending
The French philosopher Buridan once stated that "A hungry jackass, placed at an exactly equal distance between two identical piles of hay, will starve to death, as it will have no reason to select one pile over the other."
A wealthy rancher who dabbled in philosophy and mathematics decided to put Buridan's hypothesis to the test. He had 10 ramps constructed, each of which led to the exact center of a platform where on either side, two identical piles of hay were placed at an exactly equal distance. He then purchased 10 jackasses (Gohmert, Poe, Johnson, Ratcliffe, Hensarling, Barton, Culberson, Brady, McCaul and Conaway) and gave them only water for 16 hours to make sure they were good and hungry. Then each jackass was led down the ramp to the center of the platform.
Not a single one of the jackasses froze in place and starved to death, thus disproving Buridan's hypothesis.
If the chance of each jackass going to the left pile of hay is identical to the chance it will go to the right pile of hay, what are the chances that exactly 5 jackasses go each direction? Give answer in percent to 2 decimal places.
×
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http://www.ams.org/mathscinet-getitem?mr=49:9207
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MathSciNet bibliographic data MR344468 30A66 Baernstein, Albert, II A generalization of the ${\rm cos}\ \pi \,\rho$${\rm cos}\ \pi \,\rho$ theorem. Trans. Amer. Math. Soc. 193 (1974), 181–197. Article
For users without a MathSciNet license , Relay Station allows linking from MR numbers in online mathematical literature directly to electronic journals and original articles. Subscribers receive the added value of full MathSciNet reviews.
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https://blog.theleapjournal.org/2016/11/long-journey-to-sound-capital-controls.html
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## Friday, November 18, 2016
### Long journey to sound capital controls on foreign currency borrowing
by Pratik Datta and Radhika Pandey.
Policy reform happens in three stages:
Setting course
Choosing the strategy for reforms.
New law
Enacting new Parliamentary or subordinate law.
Implementation
Building State capacity to enforce the new law.
In India, the expert committee process is an important element of the first stage; we are learning how to draft better laws; and we have early insights on how to build state capacity for the third.
A major bottleneck in the implementation phase arises out of lack of coordination in these three elements. Often, expert committees recommend vital policy changes after extensive deliberations. But then implementation suffers at the end of the government and regulators. New regulations are issued after considerable delay and in a piecemeal manner. Law is too important to be left to the lawyers; when the law is drafted by people who lack the relevant domain knowledge, this gives faulty drafting.
The recent changes in the framework governing dollar denominated borrowing (referred to as external commercial borrowing (ECB) in India) is one such example of delayed and piecemeal implementation. On November 7, 2016 RBI issued a Circular No. 15 clarifying its regulation on hedging in relation to short-term ECB by infrastructure firms. RBI clarified that wherever hedging has been mandated by the RBI, the ECB borrower will be required to cover principal as well as coupon through financial hedges. Effectively, this clarifies RBI's earlier March 30, 2016 circular which, for the first time, mandated 100% hedging for infrastructure firms engaging in short-term ECBs. This marks an important shift in RBI's stance towards hedging.
### Why are regulations on hedging required?
ECBs expose borrowers to exchange rate risk. If left unhedged, this may expose the financial system to systemic risk. There is an extensive literature in international finance (see here, and here) on the adverse implications of unhedged currency exposure in the event of exchange rate fluctuations. The international policy discourse, and recent experiences of peer economies such as Indonesia and SouthAfrica, shows that addressing these concerns is helped by regulations that constrain borrowers to hedge their exchange rate exposure.
Ideally, exchange rate flexibility should give private persons ample incentive to hedge. From 2007 to 2013, India was doing well on this, but from late 2013, India has gone into a soft exchange rate peg to the USD. Under these circumstances, private persons have an incentive to borrow in USD and leave it unhedged, hoping to free ride on the peg. Unhedged foreign currency borrowing is thus particularly problematic now.
### RBI missed this point
One of the most effective arguments in favour of capital controls is this issue, of hedging requirements for foreign currency borrowing. However, for many years, while RBI had an elaborate system of capital controls on ECB, there were no hedging requirement.
In the beginning of 2014, RBI took a small step towards addressing this. Around the same time, in order to discourage banks from providing credit facilities to companies that refrain from adequate hedging against currency risk, RBI prescribed guidelines on incremental capital and provisioning requirements for banks with exposures to entities with Unhedged Foreign Currency Exposure (UFCE).
These changes did not succeed in nudging firms to hedge their exposure. In a speech, the then RBI Deputy Governor raised an alarm about the reduced propensity of firms to hedge foreign currency exposure. He noted that the hedge ratio for ECBs/FCCBs declined sharply from about 34 per cent in FY 2013-14 to 24 per cent during April-August, 2014 with very low ratio of about 15 per cent in July-August 2014.
The IMF Article IV Report in March 2015 on India highlighted concerns of rising unhedged corporate exposure and underscored the need to strengthen regulatory oversight. The report recommended strengthened monitoring of corporate vulnerabilities in the wake of increased unhedged foreign currency exposure of banks. A year later, in March 2016 another IMF report raised concerns about unhedged foreign currency exposure. But the RBI abstained from imposing a direct obligation on firms to hedge their foreign currency exposure.
### Sahoo Committee recommended hedging
In Februrary 2015, the Sahoo Committee for the first time recommended hedging to address the underlying systemic risk emanating from ECBs. The Sahoo Committee report recommended that the regulatory framework should require mandatory hedging by Indian firms which borrow in foreign currency. It recommended a complete dismantling of the extant regime of complicated controls on ECBs, as this merely introduced bureaucratic overhead and did not address any market failure; it recommended focusing the capital control on ECB on this one issue: hedging. The report recommended that the required hedge ratio should be decided by the MOF-RBI Committee keeping in view the financing needs of the firms and of the economy, the development of onshore currency derivatives markets and any other systemic concern such as volatility in global risk tolerance.
### Partial and delayed implementation by RBI
While the Sahoo Committee submitted its report in February, 2015, the RBI did not prescribe mandatory hedging till March 30, 2016. Even then, RBI mandated hedging only for infrastructure firms that borrow for less than 5 years. While this is a good step as most infrastructure firms do not have a natural hedge against the currency risk, this is only an incremental move towards the optimal framework of mandating a hedge ratio across all sectors and across all durations of borrowing. As recommended by the Sahoo report, hedging should be mandated for all kinds of ECBs unless there is a natural hedge.
### Conclusion
This episode illustrates how economic policy failures arise from communication gaps between expert committees, which figure out what is to be done, and the different arms of the State which implement it. Often the latter are either not fully aware of the committee's thinking, or have misaligned incentives. When the drafting of legal instruments is tightly linked to sound domain knowledge, the results are better.
The authors are researchers at the National Institute for Public Finance and Policy.
Please note: Comments are moderated. Only civilised conversation is permitted on this blog. Criticism is perfectly okay; uncivilised language is not. We delete any comment which is spam, has personal attacks against anyone, or uses foul language. We delete any comment which does not contribute to the intellectual discussion about the blog article in question.
LaTeX mathematics works. This means that if you want to say $10 you have to say \$10.
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https://www.dcode.fr/lagrange-interpolating-polynomial
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Lagrange Interpolating Polynomial
Tool to find the equation of a function. Lagrange Interpolating Polynomial is a method for finding the equation corresponding to a curve having some dots coordinates of it.
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Lagrange Interpolating Polynomial
Lagrange Interpolation Calculator
Extrapolation
Tool to find the equation of a function. Lagrange Interpolating Polynomial is a method for finding the equation corresponding to a curve having some dots coordinates of it.
How to find the equation of a curve using Lagrange?
Lagrange polynomials are computed using the formula :
$$P(X)=\sum_{j=0}^n y_j \left(\prod_{i=0,i\neq j}^n \frac{X-x_i}{x_j-x_i} \right)$$
with $P(X)$ the Lagrande polynomial and the dots $(x_0, y_0),\dots,(x_n, y_n)$ and $x_i$ distinct.
From the points whose coordinates are known, the lagrange polynomial calculator can thus predict other points based on the assumption that the curve formed by these points is derived from a polynomial equation.
dCode allow to use the Lagrangian method for interpolating a Polynomial and finds back the original equation using known points (x,y) values.
Example: By the knowledge of the points $(x,y)$ : $(0,0),(2,4),(4,16)$ the Polynomial Lagrangian Interpolation method allow to find back the équation $y = x^2$. Once deducted, the interpolating function $f(x) = x^2$ allow to estimate the value for $x = 3$, here $f(x) = 9$.
The Lagrange interpolation method allows a good approximation of polynomial functions.
There are others interpolation formulas (rather than Lagrange/Rechner) such as Neville interpolation also available online on dCode.
What are the limits for Interpolating with Lagrange?
Since the complexity of the calculations increases with the number of points, the program is limited to 25 coordinates (with distinct x-values in the rational number set Q).
Source code
dCode retains ownership of the online 'Lagrange Interpolating Polynomial' tool source code. Except explicit open source licence (indicated CC / Creative Commons / free), any algorithm, applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any function (convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (PHP, Java, C#, Python, Javascript, Matlab, etc.) no data, script or API access will be for free, same for Lagrange Interpolating Polynomial download for offline use on PC, tablet, iPhone or Android !
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http://math.stackexchange.com/questions/77297/set-of-measure-zero-at-end-of-closed-interval
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# set of measure zero at end of closed interval
I'm sure this is elementary, but:
If a 1-D function is bounded everywhere except at a point P (measure zero), then the integral exists. So why should it matter if P is at the end of the integration interval?
Presumably the same is true of a line integral in, say, R3 --- which would seem to imply that the path for a closed line integral can include a countable number of discontinuities. But what happens if the closed integral is calculated in such a way that the endpoints a=b are where the function is unbounded?
Taking this one more step, the closed line integral, by Stokes' theorem, can be written as a surface integral of the curl. As long as the regions is simply connected. But if, say, simply connectedness fails at the origin, why should it matter -- isn't that just a set of measure zero for the surface integral?
Clearly, I'm confused and/or missing something basic.
thanks!
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How do you mean unbounded? You could just redefine the function in all "bad" points if they remain to be a null set. Note that a countable set is of measure zero, but it can be way large. For example the Cantor set. – Jonas Teuwen Oct 30 '11 at 20:48
A function cannot be unbounded at a point. Whenever you think about a function, like say $\tan(x)$ which is not bounded "at" $\frac{\pi}{2}$, it is actually not bounded on any interval containing or touching $\frac{\pi}{2}$. – N. S. Oct 30 '11 at 20:51
Maybe by terminology is poor. My apologies. So let me try an example: $\int_{-a}^a \frac{dx}{x^2}$ exists, but --- at least formally --- is not the same as $2\int_0^a \frac{dx}{x^2}$ because the latter integral doesn't exist. The difference between the two expressions is the origin, a set of measure zero, at the endpoint of the second integral. – gilonik Oct 30 '11 at 22:33
What do you mean by "simply connectedness fails at the origin"? You mean at "the endpoints a=b"? Can you give me an example? – savick01 Oct 30 '11 at 22:35
@Jonas, the way I read your comment, it presents the Cantor set as an example of a countable set. Maybe you didn't mean it to be read that way. Anyway, the Cantor set is not countable. – Gerry Myerson Oct 30 '11 at 23:49
It does matter because when you calculate the integral of $\int_0^1 x^{-2} dx$, you actually calculate a different KIND of integral than the integral say $\int_0^1 x dx$.
If you go back to definitions: a 'normal' Riemann integral is a limit of Riemann sums. When you want to define $\int_0^1 x^{-2} dx$ you can't use this definition, because any sum can be arbitrarily huge - it is a matter of taking an appropriate midpoint near $0$, which generates arbitrarily big value. So you say: I can calculate a limit of integrals $\lim_{\varepsilon \to 0}\int_\varepsilon^1 x^{-2} dx$. But look: it is kinda trick, that you take the limit. If you want, you can say: I want the number: $\lim_{\varepsilon \to 0} \int_{-1}^{-\varepsilon} x^{-2} dx + \int_\varepsilon^1 x^{-2} dx$, to be the value of the integral $\int_{-1}^1 x^{-2} dx$.
That really shows weakness of the Riemann integral, so people usually use different definitions (like Lebesgue integral), to be able to calculate the integral of the characteristic function of $\mathbb{Q}$ or things like that. They prove that it is equal to traditional Riemann integral if Riemann integral is defined. However there are some cases where Riemann integral in the second version (with $\lim$) is defined and Lebesgue integral is not: that is because for example $\int_1^\infty{}\frac{sin(x)}{x}$ for Riemann is the limit when you go to infinity and Lebesgue looks at the whole halfline and he sees infinitely big surface (I mean "the surface below the graph") above zero and below zero and he does know how much $\infty - \infty$ is.
At the beginning you say bounded and then you switch to discontinuous, I don't get it. You mean that the path is not continuous or the function which is integrated along the path? I haven't heard about discontinuous path (see: path), but integrals on $\mathbb{R}$ and line integrals have indeed a lot in common.
Simple connectedness - it is a term from topology not measure theory and in topology single points sometimes really matter. For a topologist a circle without one point is an interval which is of course completely different from a circle (it is simply connected for example, but you can also notice that if you take one point out of a circle it is still connected, what is not true in case of interior points of an interval). For a topologist a disk without one point is in some way more similar to the circle than to the whole disk. EDIT: So topology sees no difference if in your formula there is a singularity at zero or at some disk (with positive measure) around it. END
Going back to simple connectedness (s.c): taking one point from an open disk spoils its s.c. And it does matter if you - for example - want to say that particular line integrals are equal, because the endpoints are equal - if you have s.c, you can use a homotopy between those paths to prove such a statement and you have a problem, when there is no homotopy (because of no s.c.). In that case an infinite value at one single point may spoil everything. Well, such is life.
There are actually no theorems in my answer, but I hope it helps a bit.
P.S. If you calculate the 'limit' Riemann integral and normal Riemann integral exists, they are equal, so you can use only the 'limit' one, but it is somehow pointless.
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Re: Stokes' theorem -- It's my understanding that the singularity at the origin renders the surface integral of the curl undefined. If so, it's not clear to me what that statement has to do with homotopy -- and I'm left wondering why a set of measure zero results in a non-existent integral. So then I guess what you're saying is that the surface integral does exist, but homotopy considerations show that instead it's Stokes' theorem which fails. Yes? – gilonik Oct 31 '11 at 0:08
Yes, it is about Stokes not about the integral. But it was a general speach about simple connectedness as a topological term (which is sometimes applied to integrals). Actually Stoke's theorem may be applied to sets like an annulus. In this case you have to remember, that its boundary consists of two parts (and the integrals have to be counted "in the right direction"). – savick01 Oct 31 '11 at 0:39
Could Stokes be patched up, at least in the $\frac{\hat{\phi}}{r}$ example, but using a delta function? It sounds just like the divergence theorem applied to $\frac{\hat{r}}{r}$... – gilonik Oct 31 '11 at 1:03
@gilonik I have a counterexample! If you add a constant to the function, then closed integral doesn't change, surface integral (of the derivative) doesn't change, but the value coming from delta function does change! – savick01 Oct 31 '11 at 1:52
@gilonik My penultimate comment about infinities was a bullshit, since I mixed up values of a derivative and a function. Deleted. Anyway, trying to define value coming from delta function requires some decision on what to do with $dx$ and $dy$ (since those are good for 2D and you use delta for 1D), but it seems that any decission leads to problems with constants. By constant I mean $+5dx$ or $+5dx + 5dy$, whatever. – savick01 Oct 31 '11 at 10:38
EDIT: as pointed out in the comments, even the principal value interpretation doesn't work for this particular function. I had in mind the situation where a principal value exists because positive and negative contributions cancel out, e.g., for ${\rm p.v.}\int_{-1}^1(1/x)\,dx=0$. So much of what follows is wrong and/or not relevant to the question at hand.
I would say that $\int_{-1}^1(1/x^2)\,dx$ doesn't exist, and neither does $\int_0^1(1/x^2)\,dx$. The first integral differs from the second one in that there is something called the "principal value" defined by $${\rm p.v.}\int_{-1}^1{1\over x^2}\,dx=\lim_{a\to0}\left(\int_{-1}^{-a}{1\over x^2}\,dx+\int_a^1{1\over x^2}\,dx\right)$$ and the principal value does exist, while no principal value exists for the second integral. But the principal value isn't the integral; it's a generalization of the integral.
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...which in common parlance is what we actually call the "integral". And if we can do this (i.e., find the p.v.) for any set of measure zero, then this is why integration through a countable number of singular points is not a problem. Fabulous! – gilonik Oct 31 '11 at 0:12
Ehm... $\left(\int_{-1}^{-a} \frac1{x^2}dx + \int_a^1 \frac1{x^2}dx\right) = \frac 2a -2.$ I don't see how $\int_{-1}^1 \frac{dx}{x^2}$ has a principal value? – kahen Oct 31 '11 at 0:35
@gilonik How do you want to integrate through $\mathbb{Q}$ in that way? – savick01 Oct 31 '11 at 0:46
@kahen Oh come on, can't you see this tiny "1/" before 2 in the exponent? Yes, you've got us! It's probably time to sleep... – savick01 Oct 31 '11 at 0:49
Clearly I didn't stop to think. This p.v. argument would only work for an odd function around a symmetric interval.... I guess I'm being dense, but I'm just looking for an intuitive understanding of why $\int_{-a}^b \frac{dx}{x^2}$ is OK but $\int_0^b \frac{dx}{x^2}$ is not. Somehow that zero does not matter in the first, but does in the 2nd.... – gilonik Oct 31 '11 at 0:58
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https://www.math.princeton.edu/events/white-noise-kdv-mkdv-and-cubic-nls-circle-2010-01-21t200001
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# White noise for KdV, mKdV, and cubic NLS on the circle
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Tadahiro Oh, University of Toronto
Fine Hall 110
We discuss two methods for establishing the invariance of the white noise for the periodic KdV. First, we briefly go over the basic theory of Gaussian Hilbert spaces and abstract Wiener spaces and show that the Fourier-Lebesgue space $\mathcal{F}L^{s, p}$ captures the regualrity of the white noise for $sp < -1$. We then establish local well-posedness (LWP) of KdV via the second iteration introduced by Bourgain. This in turn provides almost sure global well-posedness (GWP) of KdV as well as the invariance of the white noise. Then, we discuss how one can use the same idea to obtain LWP of the stochastic KdV with the additive space-time white noise in the periodic setting.Next, we consider the weak convergence problem of the grand canonical ensemble (i.e. the interpolation measure of the usual Gibbs measure and the white noise) with a small parameter (tending to 0) to the white noise. This result, combined with the GWP in $H^{-1}$ by Kappeler and Topalov, provides another proof of the invariance of the white noise for KdV. In this talk, we discuss the same weak convergence problem for mKdV and cubic NLS, which provides the "formal'' invariance of the white noise. This part is a joint work with J. Quastel and B. Valko.
Lastly, if time permits, we discuss well-posedness of the Wick ordered cubic NLS on the Gaussian ensembles below $L2$. The main ingredient is nonlinear smoothing under randomization of initial data. For GWP, we also use the invariance (of the Gaussian ensemble) under the linear flow. This part is a joint work with J. Colliander.
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https://www.math.utk.edu/~phan/UTK-PDE/Vol-2.html
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# UTK-PDE DISTINGUISHED LECTURE SERIES
### University of Tennessee - Knoxville
UTK-PDE Distinguished Lecture Series is a series of lectures in partial differential equations (PDEs) delivered virtually by world renowned mathematicians. Each part in the series consists of three to five lectures covering core ideas, techniques, and state of the art in selected topics in the area of partial differential equations. Lectures will be thoughtfully designed and technically simplified so that they will be accessible to an audience with only basic background in Analysis and PDEs. All lectures will be recorded and posted together with lecture notes (Youtube Channel UTK-PDE Lecture Series). The series is founded and organized by Dr. Tuoc Phan with the support from the Department of Mathematics at the University of Tennessee - Knoxville.
Volume II (Spring 2021): Professor Jun-cheng Wei (Department of Mathematics of University of British Columbia). Enter your name and e-mail address in this form if you would like to receive reminding messages.
Brief Biography: Juncheng Wei received his Ph.D. in mathematics from the University of Minnesota in 1994. From 1994-1995, he stayed in SISSA (Italy) as a postdoc. He then came to Chinese University of Hong Kong as an assistant professor from 1995-1999, then an associate professor from 1999-2003, and a chair professor in mathematics from 2003-2009. Professor Juncheng Wei moved to University of British Columbia in 2009, and currently he is a full professor and Canada Research Chair (Tier I) there. Professor Wei has published more than 450 peer reviewed articles and many of them are in top mathematics journals such as Advances in Mathematics, Annals of Mathematics, Communication in Pure Applied Mathematics, Journal für die reine und angewandte Mathematik (Crelle's Journal). Professor Wei is well-known for his outstanding results in constructing special classes of solutions in problems on concentration phenomenon in Nonlinear PDEs, De Giorgi conjectures, phase transitions, singular perturbation problems, mean curvature flows, harmonic map flows, and many others. Professor Wei has been recognized by many prestigious awards and honors including the Silver Morningside Medal in 2010, the CMS Jeffery-Williams Prize and Simons Fellow in Mathematics in 2020. Professor Wei was an invited speaker at the International Congress of Mathematicians (ICM 2014). In 2018, professor Wei was also listed as an ISI Highly Cited Researcher. Professor Wei is currently a Fellow of Royal Society of Canada (FRSC). He also serves as an editor of many leading mathematics journals including Journal of Functional Analysis, Journal of Differential Equations, Transactions of London Mathematical Society. Additional information about Professor Wei can be found in this Wikipedia page and in his [CV].
Title: Gluing methods and Applications.
Abstract: In this lecture series, I will introduce the gluing methods and applications. Four examples of nonlinear equations will be used to illustrate the methods: 1) nonlinear Schrödinger equations (finite dimensional reduction method) 2) Allen-Cahn equation and minimal surfaces (infinite dimensional reduction method) 3) energy-critical parabolic equations (parabolic gluing method) 4) 2D Euler equation (gluing method applied to transport equation). If time permits I will also describe some applications of the reverse gluing methods including $C^{2,\alpha}$ estimates for interfaces of Allen-Cahn and non-existence of Type II blow-ups for energy-critical heat equation.
Schedule: Zoom link will be available 30 minutes before each lecture. Enter your name and e-mail address in this form if you would like to receive reminding messages.
Date/TimeZoom information Lecture Notes Lecture Videos
April 1, 2:50PM (EDT) Zoom link Lecture Slides Lecture 1
April 8, 2:50PM (EST) Zoom link Lecture Slides Lecture 2
April 15, 2:50PM (EST) Zoom link Lecture Slides Lecture 3
April 22, 2:50PM (EST) Zoom link Lecture Slides Lecture 4
April 29, 2:50PM (EST) Zoom link Lecture Slides Lecture 5
Youtube Channel: UTK-PDE Lecture Series. Feel free to subscribe.
Contact information: Write to Tuoc Phan at phan(at)math(dot)utk(dot)edu if you would like to receive the reminding messages on this event or if you have questions/requests.
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http://math.stackexchange.com/questions/153053/submanifold-of-mathbb-rn-projections-onto-tangent-spaces
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# Submanifold of $\mathbb R^n$ : projections onto tangent spaces
Let $M$ a submanifold of $\mathbb R^n$, for all $x$ in $M$, let $\pi_x:\mathbb R^n\rightarrow T_xM$ the orthogonal projection onto the tangent space $T_xM$ of $M$ at $x$.
How could you show that for all $x$ in $M$, it exists an open neighborhood $U$ of $x$, such as for all $y$ in $U\cap M$, $\pi_y$ restricted on $U$ is a diffeomorphism from $U$ onto $\pi_y(U)$?
Thank you.
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Use \mathbb{R}^n for $\mathbb{R}^n$. – M.B. Jun 2 '12 at 21:36
How can a diffeomorphism exist between $U$ (dimension $n$) and $T_yM$ (dimension strictly smaller than $n$)? Also, $\pi_y$ is a linear map, so the statement you're trying to prove sounds a bit weird IMHO. – Giuseppe Negro Jun 2 '12 at 22:33
I assume that the neighborhood is being taken with respect to $M$. – Dylan Moreland Jun 2 '12 at 22:42
It seems very plausible indeed. For small enough $U$ you can just ''flatten'' $U$ to fit onto its image in the tangent space. And $U$ is small enough such that the map is injective. – M.B. Jun 2 '12 at 23:01
The derivative of $\pi_y$ has full rank everywhere on $U$ as long as the normal space at $y$ has zero intersection with the tangent space at $x$. This is sure to happen if the angle between tangent spaces at $x$ and $y$ is small. So I guess one can begin by arguing (or recalling) that the map $y\mapsto T_yM$ (from $M$ to the Grassmannian) is continuous... – user31373 Jun 2 '12 at 23:55
show 1 more comment
Change the coordinates such as $x=0$ and $\mathbb R^n=T_xM\oplus V=\{(t,w)\}$, so $T_xM:w=0$.
By the local inverse function theorem there is an open neighborhood of $x$ such as $\pi_x:U\rightarrow\pi_x(U)$ is a diffeomorphism.
Denote by $f:V=\pi_x(U)\rightarrow U$ the inverse function. So $f$ is a local parameterization of $M$ at $x$ by a neighborhood of $0$ in $T_xM$. We have $f(0)=0$ and $d_xf=0$ (since $T_xM:w=0$).
Let $y=(t,f(t))\in U\cap M$, then $T_yM=\{(t+h,f(t)+d_tf(h))\}$.
It exists $\varepsilon>0$ such as $\|d_tf\|<\varepsilon$ for all $(t,f(t))\in U$, so $p_y$ is injective on $U$.
Let $z\in U$, we check that $d_z(p_y):T_zU\rightarrow T_yU=T_yM$ coincides with the orthogonal projection $T_zU\rightarrow T_yM$ : $p_y:U\hookrightarrow R^N\rightarrow T_yM$ so $d_z(p_y)=T_zU\hookrightarrow R^N\rightarrow T_yM$.So $d_z(p_y)$ is invertible.
So $p_y$ is a diffeomorphism on $U$.
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https://git.metabarcoding.org/lecasofts/ProcMod/commit/4dcc150c385b5f440ecb89d41835f2bd13a2266f?w=1
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Commit 4dcc150c by Eric Coissac
### New doc for .rep_matrix(x, length.out)
parent 4b8a90d8
man/rep_matrix.Rd 0 → 100644
% Generated by roxygen2: do not edit by hand % Please edit documentation in R/procmod.frame.R \name{.rep_matrix} \alias{.rep_matrix} \title{Internal function repeating a matrix.} \usage{ .rep_matrix(x, length.out) } \arguments{ \item{x}{The matrix to replicate} \item{length.out}{an interger value specifying the number of row of the returned matrix} } \value{ a new matrix with the same number of columns but with length.out rows. } \description{ repeats several times the rows of a matrix to create a new matrix with more rows. The final row count must be a multiple of the initial row count } \author{ Eric Coissac Christelle Gonindard-Melodelima }
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http://mathhelpforum.com/advanced-math-topics/213102-vectors-print.html
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# Vectors
• February 14th 2013, 05:45 AM
Tutu
Vectors
1.) Find the equation of the plane containing A(3,2,1) and the line x=1+t, y= 2-t, z = 3+2t
I know that there are two positional vectors, 3i+2j+k and i+2j+3k, and I know I have a vector equation..but what do I do? I thought of using dot product, but I don't know what I should dot..
2.) The perpendicular from a point to a line minimizes the distance from the point to that line.Use quadratic theory to find th ecoordinates of the foot of the perpendicular from (1,1,2) to the line with equations x=1+t, y=2-t, z=3+t
I really do not know how to do this one..
Thank you for your help, really would want to know how to solve these two questions, thanks so so much for your efforts in advance!
• February 14th 2013, 10:44 AM
MINOANMAN
Re: Vectors
Tutu
Do not be so desperate..use your brain.... take two values for t (t=0) and t=1 and find two more points of the plane....for t=0 you will find that the point Q(1,2,3) lies on the plane and fot t=1 the point R(2,1,5) lies on the plane...then your problem is to find the equation of a plane given 3 points...easy....
the rest is really easy
MINOAS
• February 14th 2013, 11:44 AM
Plato
Re: Vectors
Quote:
Originally Posted by Tutu
1.) Find the equation of the plane containing A(3,2,1) and the line x=1+t, y= 2-t, z = 3+2t
2.) The perpendicular from a point to a line minimizes the distance from the point to that line.Use quadratic theory to find th ecoordinates of the foot of the perpendicular from (1,1,2) to the line with equations x=1+t, y=2-t, z=3+t
1) $t=0\text{ so }B(1,2,3)$ is a point on the line.
Let $N=\overrightarrow {BA} \times \left\langle {1, - 1,2} \right\rangle$.
Now you have a point and a normal. Write the equation of the plane.
2) If $P$ is a point not on line $\ell: Q+tD$ then the distance:
$\math{D}(P;\ell)=\frac{|\overrightarrow {QP}\times D|}{\|D\|}.$
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http://ajaxsoundstudio.com/pyodoc/perftips.html
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# How to improve performance of your pyo programs
This document lists various tips that help to improve the performance of your pyo programs.
## Python tips
There is not much you can do at the Python level because once the script has finished its execution run, almost all computations are done in the C level of pyo. Nevertheless, there is these two tricks to consider:
### Adjust the interpreter’s “check interval”
You can change how often the interpreter checks for periodic things with sys.setcheckinterval(interval). The defaults is 100, which means the check is performed every 100 Python virtual instructions. Setting it to a larger value may increase performance for programs using threads.
### Use the subprocess or multiprocessing modules
You can use the subprocess or multiprocessing modules to spawn your processes on multiple processors. From the python docs:
The multiprocessing package offers both local and remote concurrency, effectively side-stepping the Global Interpreter Lock by using subprocesses instead of threads. Due to this, the multiprocessing module allows the programmer to fully leverage multiple processors on a given machine. It runs on both Unix and Windows.
Here is a little example of using the multiprocessing module to spawn a lot of sine wave computations to multiple processors.
#!/usr/bin/env python
# encoding: utf-8
"""
Spawning lot of sine waves to multiple processes.
From the command line, run the script with -i flag.
Call quit() to stop the workers and quit the program.
"""
import time
import multiprocessing
from random import uniform
from pyo import Server, SineLoop
class Group(multiprocessing.Process):
def __init__(self, num_of_sines):
super(Group, self).__init__()
self.daemon = True
self._terminated = False
self.num_of_sines = num_of_sines
def run(self):
# All code that should run on a separated
# core must be created in the run() method.
self.server = Server()
self.server.deactivateMidi()
self.server.boot().start()
freqs = [uniform(400,800) for i in range(self.num_of_sines)]
self.oscs = SineLoop(freq=freqs, feedback=0.1, mul=.005).out()
# Keeps the process alive...
while not self._terminated:
time.sleep(0.001)
self.server.stop()
def stop(self):
self._terminated = True
if __name__ == '__main__':
# Starts four processes playing 500 oscillators each.
jobs = [Group(500) for i in range(4)]
[job.start() for job in jobs]
def quit():
"Stops the workers and quit the program."
[job.stop() for job in jobs]
exit()
### Avoid memory allocation after initialization
Dynamic memory allocation (malloc/calloc/realloc) tends to be nondeterministic; the time taken to allocate memory may not be predictable, making it inappropriate for real time systems. To be sure that the audio callback will run smoothly all the time, it is better to create all audio objects at the program’s initialization and call their stop(), play(), out() methods when needed.
Be aware that a simple arithmetic operation involving an audio object will create a Dummy object (to hold the modified signal), thus will allocate memory for its audio stream AND add a processing task on the CPU. Run this simple example and watch the process’s CPU growing:
from pyo import *
import random
s = Server().boot()
env = Fader(0.005, 0.09, 0.1, mul=0.2)
jit = Randi(min=1.0, max=1.02, freq=3)
sig = RCOsc(freq=[100,100], mul=env).out()
def change():
freq = midiToHz(random.randrange(60, 72, 2))
# Because jit is a PyoObject, both freq+jit and freq-jit will
# create a Dummy object, for which a reference will be created and
# saved in the sig object. The result is both memory and CPU
# increase until something bad happens!
sig.freq = [freq+jit, freq-jit]
env.play()
pat = Pattern(change, time=0.125).play()
s.gui(locals())
An efficient version of this program should look like this:
from pyo import *
import random
s = Server().boot()
env = Fader(0.005, 0.09, 0.1, mul=0.2)
jit = Randi(min=1.0, max=1.02, freq=3)
# Create a Sig object to hold the frequency value.
frq = Sig(100)
# Create the Dummy objects only once at initialization.
sig = RCOsc(freq=[frq+jit, frq-jit], mul=env).out()
def change():
freq = midiToHz(random.randrange(60, 72, 2))
# Only change the value attribute of the Sig object.
frq.value = freq
env.play()
pat = Pattern(change, time=0.125).play()
s.gui(locals())
### Don’t do anything that can trigger the garbage collector
The garbage collector of python is another nondeterministic process. You should avoid doing anything that can trigger it. So, instead of deleting an audio object, which can turn out to delete many stream objects, you should just call its stop() method to remove it from the server’s processing loop.
## Pyo tips
Here is a list of tips specific to pyo that you should consider when trying to reduce the CPU consumption of your audio program.
### Mix down before applying effects
It is very easy to over-saturate the CPU with pyo, especially if you use the multi-channel expansion feature. If your final output uses less channels than the number of audio streams in an object, don’t forget to mix it down (call its mix() method) before applying effects on the sum of the signals.
Consider the following snippet, which create a chorus of 50 oscillators and apply a phasing effect on the resulting sound:
src = SineLoop(freq=[random.uniform(190,210) for i in range(50)],
feedback=0.1, mul=0.01)
lfo = Sine(.25).range(200, 400)
phs = Phaser(src, freq=lfo, q=20, feedback=0.95).out()
This version uses around 47% of the CPU on my Thinkpad T430, i5 3320M @ 2.6GHz. The problem is that the 50 oscillators given in input of the Phaser object creates 50 identical Phaser objects, one for each oscillator. That is a big waste of CPU. The next version mixes the oscillators into a stereo stream before applying the effect and the CPU consumption drops to ~7% !
src = SineLoop(freq=[random.uniform(190,210) for i in range(50)],
feedback=0.1, mul=0.01)
lfo = Sine(.25).range(200, 400)
phs = Phaser(src.mix(2), freq=lfo, q=20, feedback=0.95).out()
When costly effects are involved, this can have a very drastic impact on the CPU usage.
### Stop your unused audio objects
Whenever you don’t use an audio object (but you want to keep it for future uses), call its stop() method. This will inform the server to remove it from the computation loop. Setting the volume to 0 does not save CPU (everything is computed then multiplied by 0), the stop() method does. My own synth classes often looks like something like this:
class Glitchy:
def __init__(self):
self.feed = Lorenz(0.002, 0.8, True, 0.49, 0.5)
self.amp = Sine(0.2).range(0.01, 0.3)
self.src = SineLoop(1, self.feed, mul=self.amp)
self.filt = ButLP(self.src, 10000)
def play(self, chnl=0):
self.feed.play()
self.amp.play()
self.src.play()
self.filt.out(chnl)
return self
def stop(self):
self.feed.stop()
self.amp.stop()
self.src.stop()
self.filt.stop()
return self
### Control attribute with numbers instead of PyoObjects
Objects internal processing functions are optimized when plain numbers are given to their attributes. Unless you really need audio control over some parameters, don’t waste CPU cycles and give fixed numbers to every attribute that don’t need to change over time. See this comparison:
n = Noise(.2)
# ~5% CPU
p1 = Phaser(n, freq=[100,105], spread=1.2, q=10,
feedback=0.9, num=48).out()
# ~14% CPU
p2 = Phaser(n, freq=[100,105], spread=Sig(1.2), q=10,
feedback=0.9, num=48).out()
Making the spread attribute of p2 an audio signal causes the frequency of the 48 notches to be recalculated every sample, which can be a very costly process.
### Check for denormal numbers
From wikipedia:
In computer science, denormal numbers or denormalized numbers (now often called subnormal numbers) fill the underflow gap around zero in floating-point arithmetic. Any non-zero number with magnitude smaller than the smallest normal number is ‘subnormal’.
The problem is that some processors compute denormal numbers very slowly, which makes grow the CPU consumption very quickly. The solution is to wrap the objects that are subject to denormals (any object with an internal recursive delay line, ie. filters, delays, reverbs, harmonizers, etc.) in a Denorm object. Denorm adds a little amount of noise, with a magnitude just above the smallest normal number, to its input. Of course, you can use the same noise for multiple denormalizations:
n = Noise(1e-24) # low-level noise for denormals
src = SfPlayer(SNDS_PATH+"/transparent.aif")
dly = Delay(src+n, delay=.1, feedback=0.8, mul=0.2).out()
rev = WGVerb(src+n).out()
### Use a PyoObject when available
Always look first if a PyoObject does what you want, it will always be more efficient than the same process written from scratch.
This construct, although pedagogically valid, will never be more efficient, in term of CPU and memory usage, than a native PyoObject (Phaser) written in C.
a = BrownNoise(.02).mix(2).out()
lfo = Sine(.25).range(.75, 1.25)
filters = []
for i in range(24):
freq = rescale(i, xmin=0, xmax=24, ymin=100, ymax=10000)
filter = Allpass2(a, freq=lfo*freq, bw=freq/2, mul=0.2).out()
filters.append(filter)
It is also more efficient to use Biquadx(stages=4) than a cascade of four Biquad objects with identical arguments.
### Avoid trigonometric computation
Avoid trigonometric functions computed at audio rate (Sin, Cos, Tan, Atan2, etc.), use simple approximations instead. For example, you can replace a clean Sin/Cos panning function with a cheaper one based on Sqrt:
# Heavier
pan = Linseg([(0,0), (2, 1)]).play()
left = Cos(pan * math.pi * 0.5, mul=0.5)
right = Sin(pan * math.pi * 0.5, mul=0.5)
a = Noise([left, right]).out()
# Cheaper
pan2 = Linseg([(0,0), (2, 1)]).play()
left2 = Sqrt(1 - pan2, mul=0.5)
right2 = Sqrt(pan2, mul=0.5)
a2 = Noise([left2, right2]).out()
### Use approximations if absolute precision is not needed
When absolute precision is not really important, you can save precious CPU cycles by using approximations instead of the real function. FastSine is an approximation of the sin function that can be almost twice cheaper than a lookup table (Sine). I plan to add more approximations like this one in the future.
Some times it possible to use the same signal for parallel purposes. Let’s study the next process:
# single white noise
noise = Noise()
# denormal signal
denorm = noise * 1e-24
# little jitter around 1 used to modulate frequency
jitter = noise * 0.0007 + 1.0
# excitation signal of the waveguide
source = noise * 0.7
src = ButLP(source, freq=1000, mul=env)
wg = Waveguide(src+denorm, freq=100*jitter, dur=30).out()
Here the same white noise is used for three purposes at the same time. First, it is used to generate a denormal signal. Then, it is used to generate a little jitter applied to the frequency of the waveguide (that adds a little buzz to the string sound) and finally, we use it as the excitation of the waveguide. This is surely cheaper than generating three different white noises without noticeable difference in the sound.
### Leave ‘mul’ and ‘add’ attributes to their defaults when possible
There is an internal condition that bypass the object “post-processing” function when mul=1 and add=0. It is a good practice to apply amplitude control in one place instead of messing with the mul attribute of each objects.
# wrong
n = Noise(mul=0.7)
bp1 = ButBP(n, freq=500, q=10, mul=0.5)
bp2 = ButBP(n, freq=1500, q=10, mul=0.5)
bp3 = ButBP(n, freq=2500, q=10, mul=0.5)
rev = Freeverb(bp1+bp2+bp3, size=0.9, bal=0.3, mul=0.7).out()
# good
n = Noise(mul=0.25)
bp1 = ButBP(n, freq=500, q=10)
bp2 = ButBP(n, freq=1500, q=10)
bp3 = ButBP(n, freq=2500, q=10)
rev = Freeverb(bp1+bp2+bp3, size=0.9, bal=0.3).out()
Even if they run in different threads, with different priorities, the audio callback and the graphical interface of a python program are parts of a unique process, sharing the same CPU. Don’t use the Server’s GUI if you don’t need to see the meters or use the volume slider. Instead, you could start the script from command line with -i flag to leave the interpreter alive.
\$ python -i myscript.py
### List of CPU intensive objects
Here is a non-exhaustive list of the most CPU intensive objects of the library.
• Analysis
• Yin
• Centroid
• Spectrum
• Scope
• Arithmetic
• Sin
• Cos
• Tan
• Tanh
• Atan2
• Dynamic
• Compress
• Gate
• Special Effects
• Convolve
• Prefix Expression Evaluator
• Expr
• Filters
• Phaser
• Vocoder
• IRWinSinc
• IRAverage
• IRPulse
• IRFM
• Fast Fourier Transform
• CvlVerb
• Phase Vocoder
• Almost every objects!
• Signal Generators
• LFO
• Matrix Processing
• MatrixMorph
• Table Processing
• Granulator
• Granule
• Particule
• OscBank
• Utilities
• Resample
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https://brilliant.org/problems/percentage-5/
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# Percentage
Algebra Level 1
If Rohan's height is 20% less than Raj's height, by how much percent Raj's height is more than Rohan's height?
×
|
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|
http://openstudy.com/updates/4fb85f57e4b05565342dafe3
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## malexander Group Title Hi. I wanted to know how does one know when to use the substitution rule for integrals and when not too? 2 years ago 2 years ago Edit Question Delete Cancel Submit
• This Question is Closed
1. saifoo.khan
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@satellite73
• 2 years ago
2. lgbasallote
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take the derivative of u....if that du is present in the integrand you can use sub
• 2 years ago
3. satellite73
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don't use them on saturday night. go out and party
• 2 years ago
4. lgbasallote
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wait...we're talking about u-sub right? not algebraic sub?
• 2 years ago
5. lgbasallote
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lol sat
• 2 years ago
6. malexander
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@lgbasallote yep I am. I wanted to know when you look at an integral problem, how do you know to use either u-substitution or not.
• 2 years ago
7. lgbasallote
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go out and integrate?
• 2 years ago
8. lgbasallote
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@malexander it involves mastery of derivatives...if you know many derivativves you can see them immediately...if not..you can try u-ing then derive it...
• 2 years ago
9. satellite73
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a function multiplied by something that is either the derivative, or a constant multiple of the derivative
• 2 years ago
10. satellite73
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$\int\sqrt{x^3+3}x^2dx$ for example, because the derivative of $$x^3+3$$ is $$3x^2$$ and what i wrote above was wrong
• 2 years ago
11. satellite73
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should have been $\int f(g(x))g'(x)dx$
• 2 years ago
12. lgbasallote
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^integral of the chain rule
• 2 years ago
13. lgbasallote
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just noticed lo
• 2 years ago
14. lgbasallote
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lol*
• 2 years ago
15. marcoduuuh
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Don't use it on Sundays either, yolo.
• 2 years ago
16. malexander
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Your confusing me @satellite73. Um. Lets say you have these four integrals (question 2). In this question, which one would you need u-substitution and why?
• 2 years ago
##### 1 Attachment
17. lgbasallote
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2c
• 2 years ago
18. lgbasallote
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2b
• 2 years ago
19. malexander
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Why those @lgbasallote ?
• 2 years ago
20. lgbasallote
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$\large \int \frac{3x^3}{\sqrt{x^4 + 1}} = 3\int \frac{x^3}{\sqrt{x^4 + 1}}$ if i let u = x^4 + 1 du = 4x^3 the constant 4 is not important...but x^3 is...and it is present in the integrand so you can use u-sub
• 2 years ago
21. lgbasallote
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2d is u-subbable too
• 2 years ago
22. malexander
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Oh okay. That makes a bit more sense @lgbasallote . However, I thought we were not able to integrate fractions? (Im a cal 1 student, maybe inter grating fractions is in cal 2)
• 2 years ago
23. lgbasallote
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integrating fractions....for example 1/u^2 1/u^2 = u^(-2) according to basic algebra according to basic integration...you can use power rule on that..i assume you're familiar with that note: NEVER use power rule on 1/u <---the integral of that is automatically ln u
• 2 years ago
24. lgbasallote
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also note that i am using u...this is because u is a function of x meaning it is an expression..not limited to only a variable
• 2 years ago
25. malexander
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right, i remember that @lgbasallote about 1/u^2..and also thats fine, we use "u" in class
• 2 years ago
26. malexander
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@lgbasallote ln is in calc 2, so i hope i get to do that next semester hehe...i think i just need to do more problems with integration then...
• 2 years ago
27. lgbasallote
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i see...so you're just learning u-sub...try integrating the ones i said..2b and 2d
• 2 years ago
28. malexander
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will do!
• 2 years ago
29. malexander
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thanks again @lgbasallote ....i have another question...do u mind me asking it here, or posting another question box?
• 2 years ago
30. lgbasallote
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new post...im too lagged for a long thread lol
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31. malexander
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LOL! ok sounds good
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Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.
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https://bi-level.org/introduction-to-bilevel-optimization/
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It is well known that, without loss of generality, an optimization problem can be defined as finding the set:
\begin{align} \label{eqn:Xargmin}
X^* &= \arg \min_{\vec{x} \in X} f(\vec{x}) \\ \nonumber
&= \{ \vec{x}^* \in X \ : \ f(\vec{x}^*) \leq f( \vec{x} ), \
%
\forall
%
\vec{x} \in X \}, \end{align}
where a bounded below function $f$ , i.e., $f(x^*) > -\infty$ is called objective function. $X$ is a $D$-dimensional parameter space, usually $X \subset \mathbb{R}^D$ is the domain for $\vec{x}$ representing constraints on allowable values for $\vec{x}$.
After the above description, a general single-objective BO problem with single-objective functions at both levels can be defined as follows:
Definition (Bilevel Optimization Problem) The 5-tuple $(F, \ f, \ X, \ Y, \ \mathbb{R} )$ is called bilevel problem if the the upper-level/leader’s objective function $F: X \times Y \to \mathbb{R}$ and the lower-level/follower’s objective function $f: X \times Y \to \mathbb{R}$. Then, the optimization process is formulated as follows:
Minimize:
F(\vec{x},\ \vec{y}) \text{ with } \ \vec{x} \in X , \ \vec{y} \in Y
\label{eqn:minF1}
subject to:
\begin{align} \label{eqn:y-arg} & \vec{y} \in \arg \min \{ f(\vec{x}, \vec{z}) \ : \vec{z} \in Y \}\\ \label{eqn:G} \end{align}
Note that, for simplicity, equality constraints were not considered in the definition above.
The figure below shows a schematic procedure to evaluate a solution in bi-level optimization problems.
In 1985, Jeroslow probed that linear bilevel optimization problems are NP-hard. After that, Hansen et al. showed that some BO problems are strongly NP-hard, since evaluating a solution in a bilinear programming problem is also NP-hard.
### Example
Consider the following bilevel problem:
Minimize:
$$F(x, y) = x^2 + 0.1\cos(4\pi x) + y^2 + 0.1\sin(4\pi y)$$
Subject to:
$$y \in \arg \min \{ f(x, z) = (x^2 + z^2 -1)^2 \ : \ z\in Y \}$$
### Feasible Region
Th search space is defined over $X = Y = [0,1]$ and the feasible region is:
\begin{align*}
\{ (x, y)\in X \times Y \ : \ x^2+y^2 = 1 \}
&= \{ (x, \pm \sqrt{1 – x}) \ : \ x \in X \} \\
&= \{ (\cos(\theta),\ \sin(\theta)) \ : \ \theta \in [0, 2\pi) \}
\end{align*}
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http://www.jijitang.com/article/540faab320296a4535b91e0c/Finite-energy-foliations-of-tight-three-spheres-and-Hamiltonian-dynamics-or-Annals-of-Mathematics
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# Finite energy foliations of tight three-spheres and Hamiltonian dynamics | Annals of Mathematics
Abstract Surfaces of sections are a classical tool in the study of 3-dimensional dynamical systems. Their use goes back to the work of Poincaré and Birkhoff. In the present paper we give a natural generalization of this concept by constructing a system of transversal sections in the complement of finitely many distinguished periodic solutions. Such a system is established for nondegenerate Reeb flows on the tight 3-sphere by means of pseudoholomorphic curves. The applications cover the nondegenerate geodesic flows on T1S2≡ℝP3 via its double covering S3, and also nondegenerate Hamiltonian systems in ℝ4 restricted to sphere-like energy surfaces of contact type.
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https://support.bioconductor.org/p/58945/
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Question: Bioconductor 2.14 is released
0
5.5 years ago by
Dan Tenenbaum8.2k
United States
Dan Tenenbaum8.2k wrote:
Bioconductors: We are pleased to announce Bioconductor 2.14, consisting of 824 software packages, 200 experiment data packages, and more than 860 up-to-date annotation packages. There are 77 new software packages, and many updates and improvements to existing packages; Bioconductor 2.14 is compatible with R 3.1.0, and is supported on Linux, 32- and 64-bit Windows, and Mac OS X. This release includes an updated Bioconductor [Amazon Machine Image] (http://bioconductor.org/help/bioconductor-cloud-ami/). Visit [http://bioconductor.org](http://bioconductor.org) for details and downloads. Contents -------- * Getting Started with Bioconductor 2.14 * New Software Packages * NEWS from new and existing packages * Packages removed from the release Getting Started with Bioconductor 2.14 ====================================== To update to or install Bioconductor 2.14: 1. Install R 3.1.0. Bioconductor 2.14 has been designed expressly for this version of R. 2. Follow the instructions at [http://bioconductor.org/install/](http://bioconductor.org/install/). New Software Packages ===================== There are 77 new packages in this release of Bioconductor. ABSSeq - Inferring differential expression genes by absolute expression differences between two groups, utilizing generalized Poisson model to account for over-dispersion across samples and heterogeneity of differential expression across genes. alsace - Alternating Least Squares (or Multivariate Curve Resolution) for analytical chemical data, in particular hyphenated data where the first direction is a retention time axis, and the second a spectral axis. Package builds on the basic als function from the ALS package and adds functionality for high-throughput analysis, including definition of time windows, clustering of profiles, retention time correction, etcetera. asmn - Performs all sample mean normalization using raw data output from BeadStudio and MethyLumiM data. ASSIGN - ASSIGN is a computational tool to evaluate the pathway deregulation/activation status in individual patient samples. ASSIGN employs a flexible Bayesian factor analysis approach that adapts predetermined pathway signatures derived either from knowledge-based literatures or from perturbation experiments to the cell-/tissue-specific pathway signatures. The deregulation/activation level of each context-specific pathway is quantified to a score, which represents the extent to which a patient sample encompasses the pathway deregulation/activation signature. AtlasRDF - Query the Gene Expression Atlas RDF data at the European Bioinformatics Institute using genes, experimental factors (such as disease, cell type, compound treatments), pathways and proteins. Also contains a function to perform an enrichment of your gene list across Experimental Factor Ontology (EFO) using the Atlas background set. Basic4Cseq - Basic4Cseq is an R/Bioconductor package for basic filtering, analysis and subsequent visualization of 4C-seq data. Virtual fragment libraries can be created for any BSGenome package, and filter functions for both reads and fragments and basic quality controls are included. Fragment data in the vicinity of the experiment's viewpoint can be visualized as a coverage plot based on a running median approach and a multi-scale contact profile. BEAT - Model-based analysis of single-cell methylation data BiocCheck - Bioconductor-specific package checks biosvd - The biosvd package contains functions to reduce the input data set from the feature x assay space to the reduced diagonalized eigenfeature x eigenassay space, with the eigenfeatures and eigenassays unique orthonormal superpositions of the features and assays, respectively. Results of SVD applied to the data can subsequently be inspected based on generated graphs, such as a heatmap of the eigenfeature x assay matrix and a bar plot with the eigenexpression fractions of all eigenfeatures. These graphs aid in deciding which eigenfeatures and eigenassays to filter out (i.e., eigenfeatures representing steady state, noise, or experimental artifacts; or when applied to the variance in the data, eigenfeatures representing steady-scale variance). After possible removal of steady state expression, steady-scale variance, noise and experimental artifacts, and after re-applying SVD to the normalized data, a summary html report of the eigensystem is generated, containing among others polar plots of the assays and features, a table with the list of features sortable according to their coordinates, radius and phase in the polar plot, and a visualization of the data sorted according to the two selected eigenfeatures and eigenassays with colored feature/assay annotation information when provided. This gives a global picture of the dynamics of expression/intensity levels, in which individual features and assays are classified in groups of similar regulation and function or similar cellular state and biological phenotype. CAFE - Detection and visualizations of gross chromosomal aberrations using Affymetrix expression microarrays as input ccrepe - The CCREPE (Compositionality Corrected by REnormalizaion and PErmutation) package is designed to assess the significance of general similarity measures in compositional datasets. In microbial abundance data, for example, the total abundances of all microbes sum to one; CCREPE is designed to take this constraint into account when assigning p-values to similarity measures between the microbes. The package has two functions: ccrepe: Calculates similarity measures, p-values and q-values for relative abundances of bugs in one or two body sites using bootstrap and permutation matrices of the data. nc.score: Calculates species-level co-variation and co-exclusion patterns based on an extension of the checkerboard score to ordinal data. ChIPQC - Quality metrics for ChIPseq data ChIPseeker - This package implements functions to retrieve the nearest genes around the peak, annotate genomic region of the peak. Visualization functions are implemented to summarize genomic annotation, distance to TSS, and overlap of peaks or genes. Clomial - Clomial fits binomial distributions to counts obtained from Next Gen Sequencing data of multiple samples of the same tumor. The trained parameters can be interpreted to infer the clonal structure of the tumor. CNEr - Large-scale identification and advanced visualization of sets of conserved noncoding elements. COHCAP - This package provides a pipeline to analyze single-nucleotide resolution methylation data (Illumina 450k methylation array, targeted BS-Seq, etc.). It provides QC metrics, differential methylation for CpG Sites, differential methylation for CpG Islands, integration with gene expression data, and visualization of methylation values. COMPASS - COMPASS is a statistical framework that enables unbiased analysis of antigen-specific T-cell subsets. COMPASS uses a Bayesian hierarchical framework to model all observed cell-subsets and select the most likely to be antigen-specific while regularizing the small cell counts that often arise in multi-parameter space. The model provides a posterior probability of specificity for each cell subset and each sample, which can be used to profile a subject's immune response to external stimuli such as infection or vaccination. compcodeR - This package provides extensive functionality for comparing results obtained by different methods for differential expression analysis of RNAseq data. It also contains functions for simulating count data and interfaces to several packages for performing the differential expression analysis. CompGO - This package contains functions to accomplish several tasks. It is able to download full genome databases from UCSC, import .bed files easily, annotate these .bed file regions with genes (plus distance) from aforementioned database dumps, interface with DAVID to create functional annotation and gene ontology enrichment charts based on gene lists (such as those generated from input .bed files) and finally visualise and compare these enrichments using either directed acyclic graphs or scatterplots. COPDSexualDimorphism - Sexual dimoprhic and COPD differential (SDCD) analysis contrasts regression coefficients from two stratified analysis. Stratification can be done in two ways: by COPD status or by sex. For COPD-stratified analysis, SDCD analysis contrasts sexual dimorphism between cases and controls, while sex-stratified SDCD analsysis contrasts COPD differential expression pattern between males and females. The package is meant to be used in conjunction with the package limma. CopyNumber450k - This package contains a set of functions that allow CNV calling from Illumina 450k methylation microarrays. CoverageView - This package provides a framework for the visualization of genome coverage profiles. It can be used for ChIP-seq experiments, but it can be also used for genome-wide nucleosome positioning experiments or other experiment types where it is important to have a framework in order to inspect how the coverage distributed across the genome CRISPRseek - The package includes functions to find potential guide RNAs for input target sequences, optionally filter guide RNAs without restriction enzyme cut site, or without paired guide RNAs, genome-wide search for off-targets, score, rank, fetch flank sequence and indicate whether the target and off-targets are located in exon region or not. Potential guide RNAs are annotated with total score of the top5 and topN off-targets, detailed topN mismatch sites, restriction enzyme cut sites, and paired guide RNAs. This package leverages Biostrings and BSgenome packages. DMRcate - De novo identification and extraction of differentially methylated regions (DMRs) in the human genome using Illumina Infinium HumanMethylation450 BeadChip array data. Provides functionality for filtering probes possibly confounded by SNPs and cross-hybridisation. Includes bedGraph and plotting functions. DMRforPairs - DMRforPairs allows researchers to compare n>=2 unique samples with regard to their methylation profile. The (pairwise) comparison of n unique single samples distinguishes DMRforPairs from other existing pipelines as these often compare groups of samples in either single CpG locus or region based analysis. DMRforPairs defines regions of interest as genomic ranges with sufficient probes located in close proximity to each other. Probes in one region are optionally annotated to the same functional class(es). Differential methylation is evaluated by comparing the methylation values within each region between individual samples and (if the difference is sufficiently large), testing this difference formally for statistical significance. dualKS - This package implements a Kolmogorov Smirnov rank-sum based algorithm for training (i.e. discriminant analysis--identification of genes that discriminate between classes) and classification of gene expression data sets. One of the chief strengths of this approach is that it is amenable to the "multiclass" problem. That is, it can discriminate between more than 2 classes. EDDA - EDDA can aid in the design of a range of common experiments such as RNA-seq, Nanostring assays, RIP-seq and Metagenomic sequencing, and enables researchers to comprehensively investigate the impact of experimental decisions on the ability to detect differential abundance. ELBOW - Elbow an improved fold change test that uses cluster analysis and pattern recognition to set cut off limits that are derived directly from intrareplicate variance without assuming a normal distribution for as few as 2 biological replicates. Elbow also provides the same consistency as fold testing in cross platform analysis. Elbow has lower false positive and false negative rates than standard fold testing when both are evaluated using T testing and Statistical Analysis of Microarray using 12 replicates (six replicates each for initial and final conditions). Elbow provides a null value based on initial condition replicates and gives error bounds for results to allow better evaluation of significance. fastLiquidAssociation - This package extends the function of the LiquidAssociation package for genome-wide application. It integrates a screening method into the LA analysis to reduce the number of triplets to be examined for a high LA value and provides code for use in subsequent significance analyses. flowBin - Software to combine flow cytometry data that has been multiplexed into multiple tubes with common markers between them, by establishing common bins across tubes in terms of the common markers, then determining expression within each tube for each bin in terms of the tube-specific markers. flowCL - Semantic labelling of flow cytometric cell populations. flowCyBar - A package to analyze flow cytometric data using gate information to follow population/community dynamics flowMatch - Matching cell populations and building meta-clusters and templates from a collection of FC samples. FRGEpistasis - A Tool for Epistasis Analysis Based on Functional Regression Model gaucho - Use genetic algorithms to determine the relationship between clones in heterogenous populations such as cancer sequencing samples GeneOverlap - Test two sets of gene lists and visualize the results. geneRxCluster - Detect Differential Clustering of Genomic Sites such as gene therapy integrations. The package provides some functions for exploring genomic insertion sites originating from two different sources. Possibly, the two sources are two different gene therapy vectors. Vectors are preferred that target sensitive regions less frequently, motivating the search for localized clusters of insertions and comparison of the clusters formed by integration of different vectors. Scan statistics allow the discovery of spatial differences in clustering and calculation of False Discovery Rates (FDRs) providing statistical methods for comparing retroviral vectors. A scan statistic for comparing two vectors using multiple window widths to detect clustering differentials and compute FDRs is implemented here. GenomeInfoDb - Contains data and functions that define and allow translation between different chromosome sequence naming conventions (e.g., "chr1" versus "1"), including a function that attempts to place sequence names in their natural, rather than lexicographic, order. GenomicAlignments - Provides efficient containers for storing and manipulating short genomic alignments (typically obtained by aligning short reads to a reference genome). This includes read counting, computing the coverage, junction detection, and working with the nucleotide content of the alignments. GenomicFiles - This package provides infrastructure for parallel queries distributed 'by file' or 'by range'. User defined map and reduce functions provide added flexibility for data combination and manipulation. GOTHiC - This is a Hi-C analysis package using a cumulative binomial test to detect interactions between distal genomic loci that have significantly more reads than expected by chance in Hi-C experiments. It takes mapped paired NGS reads as input and gives back the list of significant interactions for a given bin size in the genome. GSCA - GSCA takes as input several lists of activated and repressed genes. GSCA then searches through a compendium of publicly available gene expression profiles for biological contexts that are enriched with a specified pattern of gene expression. GSCA provides both traditional R functions and interactive, user-friendly user interface. iClusterPlus - Integrative clustering of multiple genomic data using a joint latent variable model INPower - An R package for computing the number of susceptibility SNPs and power of future studies massiR - Predicts the sex of samples in gene expression microarray datasets MeSHDbi - The package is unified implementation of MeSH.db, MeSH.AOR.db, and MeSH.PCR.db and also is interface to construct Gene- MeSH package (org.MeSH.XXX.db). loadMeSHDbiPkg import sqlite file and generate org.MeSH.XXX.db. meshr - A set of annotation maps describing the entire MeSH assembled using data from MeSH messina - Messina is a collection of algorithms for constructing optimally robust single-gene classifiers, and for identifying differential expression in the presence of outliers or unknown sample subgroups. The methods have application in identifying lead features to develop into clinical tests (both diagnostic and prognostic), and in identifying differential expression when a fraction of samples show unusual patterns of expression. metaMS - MS-based metabolomics data processing and compound annotation pipeline. metaseqR - Provides an interface to several normalization and statistical testing packages for RNA-Seq gene expression data. Additionally, it creates several diagnostic plots, performs meta-analysis by combinining the results of several statistical tests and reports the results in an interactive way. MIMOSA - Modeling count data using Dirichlet-multinomial and beta- binomial mixtures with applications to single-cell assays. Mirsynergy - Detect synergistic miRNA regulatory modules by overlapping neighbourhood expansion. MLSeq - This package applies several machine learning methods, including SVM, bagSVM, Random Forest and CART, to RNA-Seq data. mmnet - This package gives the implementations microbiome metabolic network constructing and analyzing. It introduces a unique metagenomic systems biology approach, mapping metagenomic data to the KEGG global metabolic pathway and constructing a systems-level network. The system-level network and the next topological analysis will be of great help to analysis the various functional properties, including regulation and metabolic functionality of the metagenome. NetPathMiner - NetPathMiner is a general framework for network path mining using genome-scale networks. It constructs networks from KGML, SBML and BioPAX files, providing three network representations, metabolic, reaction and gene representations. NetPathMiner finds active paths and applies machine learning methods to summarize found paths for easy interpretation. It also provides static and interactive visualizations of networks and paths to aid manual investigation. nondetects - Methods to model and impute non-detects in the results of qPCR experiments. npGSEA - Current gene set enrichment methods rely upon permutations for inference. These approaches are computationally expensive and have minimum achievable p-values based on the number of permutations, not on the actual observed statistics. We have derived three parametric approximations to the permutation distributions of two gene set enrichment test statistics. We are able to reduce the computational burden and granularity issues of permutation testing with our method, which is implemented in this package. npGSEA calculates gene set enrichment statistics and p-values without the computational cost of permutations. It is applicable in settings where one or many gene sets are of interest. There are also built-in plotting functions to help users visualize results. PECA - Calculates Probe-level Expression Change Averages (PECA) to identify differential expression in Affymetrix gene expression microarray studies or in proteomic studies using peptide-level mesurements respectively. PhenStat - Package contains methods for statistical analysis of phenotypic data such as Mixed Models and Fisher Exact Test. QDNAseq - Quantitative DNA sequencing for chromosomal aberrations. Rariant - The 'Rariant' package identifies single nucleotide variants from sequencing data based on the difference of binomially distributed mismatch rates between matched samples. Rcpi - The Rcpi package offers an R/Bioconductor package emphasizing the comprehensive integration of bioinformatics and chemoinformatics into a molecular informatics platform for drug discovery. RefNet - Molecular interactions with metadata, some archived, some dynamically obtained roar - Identify preferential usage of APA sites, comparing two biological conditions, starting from known alternative sites and alignments obtained from standard RNA-seq experiments. rpx - This package implements an interface to proteomics data submitted to the ProteomeXchange consortium. sangerseqR - This package contains several tools for analyzing Sanger Sequencing data files in R, including reading .scf and .ab1 files, making basecalls and plotting chromatograms. sapFinder - sapFinder is developed to automate (1) variation-associated database construction, (2) database searching, (3) post-processing, (4) HTML-based report generation in shotgun proteomics. savR - Parse Illumina Sequence Analysis Viewer (SAV) files, access data, and generate QC plots. scsR - Corrects genome-wide siRNA screens for seed mediated off-target effect. Suitable functions to identify the effective seeds/miRNAs and to visualize their effect are also provided in the package. SomaticSignatures - The SomaticSignatures package identifies mutational signatures of single nucleotide variants (SNVs). Sushi - Flexible, quantitative, and integrative genomic visualizations for publication-quality multi-panel figures TitanCNA - Hidden Markov model to segment and predict regions of subclonal copy number alterations (CNA) and loss of heterozygosity (LOH), and estimate cellular prevalenece of clonal clusters in tumour whole genome sequencing data. trackViewer - plot ChIP-seq, RNA-seq, miRNA-seq, DNA-seq and etc NGS sequence data, especially for big files. UNDO - UNDO is an R package for unsupervised deconvolution of tumor and stromal mixed expression data. It detects marker genes and deconvolutes the mixing expression data without any prior knowledge. unifiedWMWqPCR - This packages implements the unified Wilcoxon-Mann- Whitney Test for qPCR data. This modified test allows for testing differential expression in qPCR data. VariantFiltering - Filter genetic variants using different criteria such as inheritance model, amino acid change consequence, minimum allele frequencies across human populations, splice site strength, conservation, etc. viper - Inference of protein activity from gene expression data, including the VIPER and msVIPER algorithms NEWS from new and existing packages =================================== Package maintainers can add NEWS files describing changes to their packages. The following package NEWS is available: ADaCGH2 ------- Changes in version 2.3.10 (2013-12-27): - Minor changes to main vignette with a new section "Why ADaCGH2 instead of a manual solution". - Change in NAMESPACE to adapt to changes in ffbase or bit (we were getting warnings of "replacing previous import by ffbase::[.ff when loading ADaCGH2"") Changes in version 2.3.9 (2013-11-28): - Minor changes to "benchmarks.pdf": consistent usage of lty and pch for figures of reading and analysis. Changes in version 2.3.8 (2013-11-26): - Minor changes to "benchmarks.pdf". Changes in version 2.3.7 (2013-11-26): - Minor changes to "benchmarks.pdf". Changes in version 2.3.6 (2013-11-24): - Help for inputToADaCGH has a more verbose section on the need to use the right mc.cores. - Made default for mc.cores to inputToADaCGH be half the number of cores. - More changes to benchmarks.pdf, including the link to all the data. Changes in version 2.3.5 (2013-11-11): - Changes in vignette: unified all benchmarking in benchmark.pdf. - Clarified help for pSegment on loadBalance and say explicitly not the default for HaarSeg. - Note versions 2.3.3 and 2.3.4 were never placed in BioC repos. Changes in version 2.3.4 (2013-11-09): - Reorganized file location for additional files (benchmarks, long- vignette). - Addedd loadBalance as an argument to the pSegment and pChromPlot functions, so that the user can choose to use load balancing-like with both forking and MPI. See additional benchmarking vignette for tables with results. Added code to the long vignette to exercise this. Changes in version 2.3.3: - Playing with clusterApplyLB. Changes in version 2.3.2 (2013-10-22): - Import aCGH and snapCGH again. Corresponding changes in Author, init.c, R code, and C code: basically, all the code taken from those packages is not here. Changes in version 2.3.1 (2013-10-20): - Added aCGH and snapCGH code: new R and C files, with minor modifications and updates (registration of routines, no partial matching of arguments, etc) - NAMESPACE and Description reflect no longer dependency on snapCGH or aCGH. - This version works, passes tests, is checked to give the same results as previous ones, etc. But never made it into BioC repos, as on 2013-10-23 I realized aCGH and snapCGH were again in BioC devel. Changes in version 2.3.0 (2013-10-20): - Version bump for new BioC devel. affxparser ---------- Changes in version 1.36.0 (2014-04-11): - The version number was bumped for the Bioconductor release version, which is now BioC v2.14 for R (>= 3.1.0). Changes in version 1.35.3 (2014-02-28): - Same updates as in release v1.34.2. Changes in version 1.35.2 (2014-02-28): - Patches to Fusion SDK based on clang v3.4. Changes in version 1.35.1 (2014-02-27): - Same updates as in release v1.34.1. Changes in version 1.35.0 (2013-10-14): - The version number was bumped for the Bioconductor devel version. AllelicImbalance ---------------- Changes in version 1.2.0: NEW FEATURES - Faster getAlleleCounts() BUG FIXES - Fixed bug in the "realCigarPosition" function, that otherwise could generate an error. alsace ------ Changes in version 0.2: - implement overlapping segments! should be a real novelty _DONE_, Oct 24 - add quality criteria in summary _DONE_, Oct 20 - complete pipeline so that the output is an intensity matrix _DONE_ - add wrapper function for a complete analysis _DONE_ Nov 20 - add some parallellization support _IN PROGRESS_: some lapply statements have been changed into mclapply but the most time-consuming step, the ALS iterations, will remain slow. Different time windows are done in parallel, but some time windows require very few iterations, others require quite a lot. In addition, the ALS output is annoying. Also the warping can be slow with many components. - add estimation of # of components annmap ------ Changes in version 1.5.10: - IMPROVED ANNMAP-121 Allow setting of WS base url for local testing Changes in version 1.5.8: - IMPROVED ANNMAP-119 as.vector=TRUE results are now named - IMPROVED ANNMAP-120 genomeToTranscriptCoords could handle coding regions Changes in version 1.5.7: - BUG Check for uniqueness in transcriptToCodingExon, transcriptToCodingRange, transcriptToUtrExon and transcriptToUtrRange Changes in version 1.5.6: - NEW Added transcriptToUtrExon - IMPROVED Sequence removed from transcriptToCodingExon Changes in version 1.5.5: - IMPROVED ANNMAP-115 Added method geneToGeneRegionTrack to generate a list of Gviz GeneRegionTrack elements that can be passed to plotTracks Changes in version 1.5.4: - BUG ANNMAP-118 transcriptToCodingRange( ..., end='3' ) returns whole transcript for untranslated transcripts. - IMPROVED ANNMAP-114 Added additional logging when using webservice - IMPROVED ANNMAP-116 Introduce function(s) to calculate the coding length of a gene(s) - See: ?nonIntronicGeneLength and ?nonIntronicTranscriptLength. Changes in version 1.5.3: - IMPROVED ANNMAP-114 Added additional logging when using webservice - IMPROVED ANNMAP-113 Added documentation to cookbook for webservice - IMPROVED webservice json to data.frame speed improvements AnnotationDbi ------------- Changes in version 1.26: NEW FEATURES and API changes - Support for new schemaless chip packages to allow more flexible suport of non-model organisms in chip packages. - Support for Inparanoid8 objects which contain data from the most recent release of inparanoid. These objects will be available through the AnnotationHub. BUG FIXES AND CODE MAINTENANCE - PFAM and PROSITE mappings are going away! This is because these mappings are tied to the now long defunct IPI ids. Don't worry we have you covered. These ids will still be available with select(), the mappings are just bad because they can't exist without IPI ids (which we can no longer get). So for the next release if you try to use these mappings you will be warned about it. After that, you need to have made the switch to select(). * * * 1.24.x SERIES NEWS * * * AnnotationHub ------------- Changes in version 1.4.0: NEW FEATURES - Add display,AnnotationHub-method using shiny - Adds support for Inparanoid8 objects (which in turn support select, keys, columns and keytypes) - Adds local metadata caching that dramatically improves performance SIGNIFICANT USER VISIBLE CHANGES - metadata argument 'columns' replaces deprecated 'cols' BUG FIXES - metadata() returns only information on current hub elements aroma.light ----------- Changes in version 2.0.0 (2014-04-11): - The version number was bumped for the Bioconductor release version, which is now BioC v2.14 for R (>= 3.1.0). Changes in version 1.99.3 (2014-03-31): - Bumped the version such that the next release will be 2.0.0. BaseSpaceR ---------- Changes in version 1.7: NEW FEATURES - Improved API design and a cleaner representation of the BaseSpace Data Model. - New count<resource> methods. These methods should be used to get the number of instances of a particular resource which are visible under the current scope. For example, the total number of Samples within a Project. Or the total number of Files for a given AppResults. - Improved authentication process. One can now seamlessly used the R SDK from with Native Apps or Web Apps. New 'AppSessionAuth' class to handle the authentication in this cases. It extends the 'AppAuth' class, by keeping track of the AppSession Id. User-level constructors: 'authWebClient()' and 'authNativeClient()' generator .AppSessionAuth(). - New mechanism for handling the BaseSpace server responses. 'ResponseStatus' class is now used for tracking the HTTP/server response status and integrated in the 'AppAuth' interface. 'x$showResponse()' can now be used to print the (JSON) body of the last response from the server. - Integration with some Bioconductor data structures. BAM data from BaseSpace can now be easily map to 'BamFile' objects. SIGNIFICANT USER-VISIBLE CHANGES - 'authenticateClient()' function remove and replaced by 'authWebClient()' and 'authNativeClient()'. 'AppAuth' instances are used for desktop Apps only. BUG FIXES - Minor bug fixes with the authentication process. - Method dispatchment now works as intended for 'listFiles' and 'Files'. BiGGR ----- Changes in version 1.1.4: - Updated vignette. Equality constraints on GABA shunt and pentose phosphate pathway fluxes are now used in FBA and ensemble simulations. Changes in version 1.1.3: - Updated vignette and bibtex file. FBA and ensemble sampling are now done with integration of brain metabolite uptake measurement data. - Added new function 'sampleFluxEnsemble' which can be used to generate a posterior distribution of flux vectors with respect to measuerement error in certain fluxes. An example of 'sampleFluxEnsemble' has been added to the package vignette. - Added LIM model file 'Glycolysis_TCA.LIM' to the examples directory. This file contains the model which is build in the examples. - Fixed warnings in functions buildSBMLFromReactionIDs and createLIMFromSBML to seperate missing identifiers with a comma. BiocInstaller ------------- Changes in version 1.14.0: NEW FEATURES - biocUpdatePackages updates installed packages and their dependencies. BiocParallel ------------ Changes in version 0.5.5: NEW FEATURES - multicoreWorkers() determines the number of workers based on operating system (Windows: 1), user preference (via the global option options(mc.cores=...)), or system capability (detectCores()). - bpparam() selects a default BiocParallelParam, from global options or, if that fails, the most recently registered() back-end. SIGNIFICANT USER-VISIBLE CHANGES - Rename argument controlling resumption on error as BPRESUME - Default to parallel back-end (multicore on non-Windows; snow on Windows). BUG FIXES - bpvec,ANY,MulticoreParam-method with fewer tasks than cores evaluates only the cores for which tasks are defined. Changes in version 0.5.2: NEW FEATURES - mclapply(), pvec() require only length, [, and (for mclapply) [[. - pvectorize() creates a parallel version of its vectorized function argument. - MulticoreParam, SnowParam, DoparParam (foreach-derived), SerialParam to parameterize back-ends. - bplapply, bpvec as parallel evaluation models. - bpstart, bpstop, bpisup for back-end management. - bpvec has a new argument AGGREGATE, a function to specify how results are to be combined. - Support for BatchJobs back-end added, via GSOC Michel Lang. SIGNIFICANT USER-VISIBLE CHANGES - BPPARM is now used as the argument name for passing BiocParallelParam instances to functions. - bplapply and bpvec now only dispatch on X and BPPARAM. BiocStyle --------- Changes in version 1.2.0: USER VISIBLE CHANGES - Remove dependency on 'helvet' LaTeX package to allow for the same font both in Sweave and knitr - Improve package vignette by adding paragraphs about building vignettes and using bibliography - knitr chunk_opts error=FALSE by default, so failures during vignette processing are signaled to R CMD build and R CMD check - Name-mangle \comment mark-up to avoid conflicts with other LaTeX styles - Introduce \bioctitle to allow for full and short (header) titles - Add BiocStyle::latex option 'use.unsrturl=TRUE' to use the 'unsrturl' bibliography style by default BUG FIXES - Avoid use of 'titling' LaTeX package to circumvent the conflict w/ \footnote in \author biomvRCNS --------- Changes in version 1.3.3: NEW FEATURES - updates in package vignette BUG FIXES - remove limitation of maximum typecode in the plot, now using rainbow() Changes in version 1.3.2: BUG FIXES - fix the returned posterior p bsseq ----- Changes in version 0.11: - Converted to using Authors at R in the DESCRIPTIOn file. - plotRegion did not respect the col/lty/lwd argument if given explicitely as opposed to through pData(). Reported by Karen Conneely <kconnee at="" emory.edu="">. - Fixed an issue introduced by the previous change (to plotRegion). Reported (with a fix) by Tim Triche Jr <tim.triche at="" gmail.com="">. - Fixed a serious bug in collapseBSseq reported by Julien Roux <jroux at="" uchicago.edu="">: it would use the Meth values instead of Cov for the final object's Cov. However, this will result in the return object having a methylation of 100 percent across all loci, so hopefully users will have seen this for themselves. - Fixed a bug in combineList which made combineList use "slow" code even in a special case where a faster shortcut was possible. This bug fix does not change the output of the function under any input, it only makes it faster. Reported by Julien Roux <jroux at="" uchicago.edu="">. bumphunter ---------- Changes in version 1.3.5: - nearestgene() now loads TT.rda into the local environment - known_transcripts(), and consequently matchGenes(), was yielding mostly NA for the Refseq / 'annotation' column (iff there were multiple refseq ids for the given Entrez/Gene id) - Fixed data/TT.rda, as the new value of known_transcripts() Changes in version 1.3: - Fixed NAMESPACE issues. CAFE ---- Changes in version 0.99.2: - Code and man files are now limited to 80 character width per line - Code now uniformly uses 4-space indentation - Vignette now uses BiocStyle style Changes in version 0.99.1: - fixes a bug that gave an error when plotting with idiogram=TRUE. This was due to an update in the ggbio package that broke CAFE - CAFE can now be used with species other than human It is no longer limited to 22 autologous chromosomes CAMERA ------ CHANGES IN VERSION 1.19.1 * Fixed bug in the generateRules function, where in the negative mode rules with polycharged positve ions are not created CellNOptR --------- Changes in version 1.10.0 (2014-03-13): - BUG FIX * typos leading to failure fixed in cutCNOlist * typos leading to failure in CNOlist if variance were provided - CHANGES * Changed warning into errors in readMIDAS and checkSignals functions - NEW FEATURES * self loop can be read from the SIF files * readSBMLQual do not need to add dummy nodes anymore ChemmineOB ---------- Changes in version 1.2.0: NEW FEATURES - SMARTS search ChemmineR --------- Changes in version 2.16.0: NEW FEATURES - SMARTS Search availible through ChemmineOB - Folding of FPset objects - Support for SQL database updates by compound name - Coordinate re-generation via ChemmineOB improves structure rendering chimera ------- Changes in version 1.5.2: NEW FEATURES - prettyPrint function was added to generate a table delimited file output form a list of fSet objects. ChIPpeakAnno ------------ Changes in version 2.11.4: NEW FEATURE - Add selection of 'shortestDistance' to output parameter of annotatePeakInBatch. Changes in version 2.11.3: NEW FEATURE - Improved efficiency of annotatePeakInBatch. ChIPQC ------ Changes in version 1.0.0: - Initial release. cisPath ------- Changes in version 1.3.3: - improvements Changes in version 1.3.1: - documentation improvements cleanUpdTSeq ------------ Changes in version 1.1.3: NEW FEATURES - No changes classified as "new features" (package under active development) BUG FIXES - Fix the bugs 'match' requires vector arguments when using %in% Changes in version 1.1.2: NEW FEATURES - Add citation BUG FIXES - No changes classified as 'bug fixes' (package under active development) Changes in version 1.1.1: NEW FEATURES - Re-name the inst/doc directory to vignettes BUG FIXES - No changes classified as 'bug fixes' (package under active development) Changes in version 1.1.0: NEW FEATURES - New package released in bioconductor BUG FIXES - No changes classified as 'bug fixes' (package under active development) cleaver ------- Changes in version 1.1.8 (2014-03-26): - Fix missedCleavages>1. - Add argument "unique". - Add methods, Biostrings, IRanges to NAMESPACE. Changes in version 1.1.7 (2014-03-25): - Typo in the manual page. Changes in version 1.1.5 (2014-02-25): - Using AAStringSetList constructor for list of characters instead of creating a lot of AAStringSets dramatically decreases running time for cleave,AAStringSet-method. Changes in version 1.1.4 (2013-12-20): - tests: - move tests into tests/testthat to adapt to testthat 0.8 and new CRAN policy. Clomial ------- Changes in version 0.99.0 (2014-02-11): - Under review by Bioconductor. - Created. clonotypeR ---------- Changes in version 1.2.0: NEW FEATURES - Added a ?long? option to yassai_identifier(), where every amino acid is represented. This solves the problem of ID collisions, where a single identifier could be produced by two different clonotypes. - Added a new option to clonotype_table() for randomly sampling libraries. - Added a new mode to common_clonotypes() for calculating the abundance relatively to one library. - Unified the syntax of common_clonotypes() and unique_clonotypes(). BUG FIXES - Removed infinite loop in yassai_identifier() when the germinal V sequence was completely absent from the CDR3. - Corrected output bug where ?integer(0)? was returned if the V?J boundary was a codon boundary. - yassai_identifier(): properly encode the names of the V and J segments. clusterProfiler --------------- Changes in version 1.11.3: - now plotting compareClusterResult support scale the dot size by geneRatio, and it is now setting as default. <2014-01-14, Tue> - The original default parameter by="percentage" is now changing to "rowPercentage" <2014-01-14, Tue> Changes in version 1.11.2: - remove viewKEGG function <2013-11-12, Tue> - In vignette, illustrates how to visualize KEGG pathway using use pathview package. <2013-11-12, Tue> CNAnorm ------- 1.9.2: Added function CNAnormWorkflow Added window weighting (for segmentation) depending on dispersion. Fixed a bug that made plotGenome crash if the interval of interest had no valid values. Changed vignette to better reflect typical usage and defined basic and advanced use. codelink -------- Changes in version 1.32.0: - Minor fixes to documentation. - Dropped the old term "Bioarray" (originally used for the first Codelink platform) from the DESCRIPTION file. COMPASS ------- Changes in version 0.9.0: - First release. compcodeR --------- 0.99.2: Bug fixes 0.99.1: improved documentation of the compData class 0.2.0: more examples, checks and error messages 0.2.0: more options for providing user-specified values in the data simulation 0.2.0: changed the range of the color palette in the Spearman correlation plots to [-1,1] deepSNV ------- Changes in version 1.99.3 (2013-07-25): Updates - A few changes to shearwater vignette - Renamed arguments pi.gene and pi.backgr in makePrior() Bugfixes - Fixed bug in bf2Vcf() when no variant is called Changes in version 1.99.2 (2013-07-11): Updates - Updated CITATION - Added verbose option to bam2R to suppress output - Changed mode() to "integer" for value of loadAllData() Bugfixes - Fixed bug when only one variant is called in bf2Vcf() Changes in version 1.99.1 (2013-06-25): Updates - Using knitr for prettier vignettes - Including shearwater vignette Bugfixes - fixed issues with deletions in bf2Vcf() - makePrior() adds background on all sites Changes in version 1.99.0 (2013-04-30): Updates - New shearwater algorithm - Including VCF output through summary(deepSNV, value="VCF") DESeq2 ------ Changes in version 1.4.0: - *** USAGE NOTE *** Expanded model matrices are now used when betaPrior = TRUE (the default). Therefore, level comparison results should be extracted using the 'contrast' argument to the results() function. Expanded model matrices produce shrinkage of log fold changes that is independent of the choice of base level. Expanded model matrices are not used in the case of designs with an interaction term between factors with only 2 levels. - The order of the arguments 'name' and 'contrast' to the results() function are swapped, to indicate that 'contrast' should be used for the standard comparisons of levels against each other. Calling results() with no arguments will still produce the same comparison: the fold change of the last level of the last design variable over the first level of the last design variable. See ?results for more details. - The DESeq() function will automatically replace count outliers flagged by Cook's distance when there are 7 or more replicates. The DESeq() argument 'minReplicatesForReplace' (default 7) is used to decide which samples are eligible for automatic replacement. This default behavior helps to prevent filtering genes based on Cook's distance when there are many degrees of freedom. Changes in version 1.3.58: - Added a list() option to the 'contrast' argument of results(). See examples in ?results. Changes in version 1.3.24: - rlogTransformation() gains an argument 'fast', which switches to an approximation of the rlog transformation. Speed-up is ~ 2x. - A more robust estimator for the beta prior variance is used: instead of taking the mean of squared MLE betas, the prior variance is found by matching an upper quantile of the absolute value of MLE betas with an upper quantile of a zero-centered Normal distribution. Changes in version 1.3.17: - It is possible to use a log2 fold change prior (beta prior) and obtain likelihood ratio test p-values, although the default for test="LRT" is still betaPrior=FALSE. Changes in version 1.3.15: - The DESeq() function will automatically replace count outliers flagged by Cook's distance when there are 7 or more replicates. The DESeq() argument 'minReplicatesForReplace' (default 7) is used to decide which samples are eligible for automatic replacement. This default behavior helps to prevent filtering genes based on Cook's distance when there are many degrees of freedom. - The results() function produces an object of class 'DESeqResults' which is a simple subclass of 'DataFrame'. This class allows for methods to be written specifically for DESeq2 results. For example, plotMA() can be called on a 'DESeqResults' object. Changes in version 1.3.12: - Added a check in nbinomWaldTest which ensures that priors on logarithmic fold changes are only estimated for interactions terms, in the case that interaction terms are present in the design formula. Changes in version 1.3.6: - Reduced the amount of filtering from Cook's cutoff: maximum no longer includes samples from experimental groups with only 2 samples, the default F quantile is raised to 0.99, and a robust estimate of dispersion is used to calculate Cook's distance instead of the fitted dispersion. Changes in version 1.3.5: - New arguments to results(), 'lfcThreshold' and 'alternativeHypothesis', allow for tests of log fold changes which are above or below a given threshold. - plotMA() function now passes ellipses arguments to the results() function. DEXSeq ------ Changes in version 2014-03-21: - Major code revisions: the ExonCountSet object was deprecated and substituted by the DEXSeqDataSet class, a subclass of the DESeqDataSet. - DEXseq now uses the DESeq2 package as internal engine and backbone for all analyses - All functions and methods for the ExonCountSet object were replaced by new functions - DEXSeq is now better integrated with other Bioconductor packages - We now use knitr to build the vignette DiffBind -------- Changes in version 1.10.0: - Counting * New: option to compute summits * New: option to center peaks with fixed width around summits * New: scores for summits (height, position) and CPM for TMM values * New: filter reads by mapping quality (mapQCth) * New: support for PE bam data using summarizeOverlaps * Remove: bCalledMask (now always TRUE) * Change: insertLength to fragmentSize * Add: fragmentSize can be a vector with a size for each sample * Change: fragmentSize default is 125 bp - Plotting * Change: colors based on CRUK color scheme * PCA plots * New: legend * New: label parameter for adding text labels of points in 2D plot * Venn diagrams * New: plot overlaps of differentially bound sites by specifying contrasts, thresholds etc. * New: able to return overlapping peaksets as GRanges directly * New: able to generate new DBA object consisting of overlapping peaks * New: labelAttributes for controlling default labels * New: default main and sub titles * Heatmaps * Fix: don?t plot column vector for attributes where every sample has a different value - General * New: add attribute value: DBA_ALL_ATTRIBUTES * Change: SN (signal/noise) to FRIP (fraction of reads in peaks) * Change: ?Down? to ?Loss? and Up? to ?Gain? * Vignette * Change: vignette uses BiocStyles and dynamically generated figures * Change: example data based on hg19 instead of hg18 * Change: example reads from bam files instead of bed files * New: section on using DiffBind and ChIPQC together * New configuration defaults options (DBA$config): * Metadata name strings: ID, Tissue, Factor, Condition, Treatment, Caller * th: significance threshold * bUsePval * fragmentSize * mapQCth: filter reads by mapping quality * fragments (for summarizeOverlaps) - Bugs/Issues * Fix: bRemoveDuplicates had some unpredictable behaviour * Fix: chrN_random were being counted against chrN * Disable: tamoxifen_GEO.R doesn?t work after SRA changed format of archived data easyRNASeq ---------- Changes in version 1.99.3: - Replicated the bug fixing of version 1.8.8. Changes in version 1.99.2: - Added missing imports Changes in version 1.99.1: - Fixed a bug in the getBamFileList function that prevented reporting accurate error/warning messages. - Updated the package dependencies. Changes in version 1.99.0: - Ported the final changes from the Git repository that make the simpleRNASeq function functional. - Bumped the version number to 1.99 as these are major changes and hence next Bioc release will have easyRNASeq 2.0.0. Changes in version 1.9.7: - Same as release 1.8.7 change. Changes in version 1.9.6: - Ported changes from the Git repository including further class refinements and unit testing. Changes in version 1.9.5: - Automatic version number bump by Bioc Changes in version 1.9.4: - Mirrored changes in version 1.8.6 Changes in version 1.9.3: - Mirrored changes in version 1.8.5 Changes in version 1.9.2: - Ported version 1.8.4 changes to the development version - Started to import new classes from the git repository as part of the package main function re-implementation Changes in version 1.9.1: - Change from Bioc to insert GenomicAlignments Changes in version 1.9.0: - No changes, new development version EBImage ------- Changes in version 4.6.0: NEW FEATURES - 'toRGB' function for convenient grayscale to RGB conversion - 'luminance' mode in 'channel' for luminance-preserving RGB to grayscale conversion SIGNIFICANT USER-VISIBLE CHANGES - Performance improvements to: 'Image', 'is.Image', 'readImage', 'writeImage', 'show', 'normalize', 'getFrame', 'selectChannel', 'rgbImage', 'colorLabels', 'flip'/'flop' - Reduced memory footprint of 'readImage' - When called on an 'Image' object, 'as.Image' returns its argument rather than the Grayscale-coerced copy - 'displayRaster' sets 'parusr' coordinates to image pixel coordinates easing up plot annotation BUG FIXES - 'getFrame', 'getNumberOfFrames' and 'colorLabels' support multi- dimensional images - Proper handling of multi-dimensional character arrays by the 'Image' constructor - Fixed 'getFrame' and 'combine' in case of single-channel Color Images - Fixed color mode check in 'validImageObject' - Proper 'fg.col' and 'bg.col' color handling in 'tile' - Updates to documentation EDASeq ------ Changes in version 1.9: - Added method plotRLE for Relative Log Expression (RLE) plots. EDDA ---- Changes in version 0.99.2: SIGNIFICANT USER-VISIBLE CHANGES - Put "NEWS.Rd" in EDDA/. - Change biocViews to DESCRIPTION file. - Modify DESCRIPTION and NAMESPACE file. - move the data to EDDA/inst/extdata. Changes in version 0.99.1: SIGNIFICANT USER-VISIBLE CHANGES - Put "EDDA.Rnw" in EDDA/vignettes. - Remove "library("EDDA");" in file man/EDDA-package.Rd. - Clean up pre-defined tempates in man files. - Use TRUE instead of T and FALSE instead of F. - Clean R code by breaking code less 80 characters, removing tabs and using indent by a multiple of 4 spaces. NEW FEATURES - Add biocViews to DESCRIPTION file. - Add KEYWORDS for each function man file. - Add "NEWS.Rd" in EDDA/inst/. Changes in version 0.99.0: SIGNIFICANT USER-VISIBLE CHANGES - Submit EDDA edgeR ----- Changes in version 3.6.0: - Improved treatment of fractional counts. Previously the classic edgeR pipeline permitted fractional counts but the glm pipeline did not. edgeR now permits fractional counts throughout. - All glm-based functions in edgeR now accept quantitative observation-level weights. The glm fitting function mglmLS() and mglmSimple() are retired, and all glm fitting is now done by either mglmLevenberg() or mglmOneWay(). - New capabilities for robust estimation allowing for observation- level outliers. In particular, the new function estimateGLMRobustDisp() computes a robust dispersion estimate for each gene. - More careful calculation of residual df in the presence of exactly zero fitted values for glmQLFTest() and estimateDisp(). The new code allows for deflation of residual df for more complex experimental designs. - New function processHairpinReads() for analyzing data from shRNA-seq screens. - New function sumTechReps() to collapse counts over technical replicate libraries. - New functions nbinomDeviance() and nbinomUnitDeviance. Old function deviances.function() removed. - New function validDGEList(). - rpkm() is now a generic function, and it now tries to find the gene lengths automatically if available from the annotation information in a DGEList object. - Subsetting a DGEList object now has the option of resetting to the library sizes to the new column sums. Internally, the subsetting code for DGEList, DGEExact, DGEGLM, DGELRT and TopTags data objects has been simplified using the new utility function subsetListOfArrays in the limma package. - To strengthen the interface and to strengthen the object-orientated nature of the functions, the DGEList methods for estimateDisp(), estimateGLMCommonDisp(), estimateGLMTrendedDisp() and estimateGLMTagwiseDisp no longer accept offset, weights or AveLogCPM as arguments. These quantities are now always taken from the DGEList object. - The User's Guide has new sections on read alignment, producing a table of counts, and on how to translate scientific questions into contrasts when using a glm. - camera.DGEList(), roast.DGEList() and mroast.DGEList() now include ... argument. - The main computation of exactTestByDeviance() now implemented in C++ code. - The big.count argument has been removed from functions exactTestByDeviance() and exactTestBySmallP(). - New default value for offset in dispCoxReid. - More tolerant error checking for dispersion value when computing aveLogCPM(). - aveLogCPM() now returns a value even when all the counts are zero. - The functions is.fullrank and nonEstimable are now imported from limma. eiR --- Changes in version 1.4.0: NEW FEATURES - eiCluster can now cluster subsets of database - use new features in ChemmineR to store duplicate descriptors only once. - embedded descriptors now stored in database and the matrix file is written out only as needed by LSH to create an index. UPGRADING - Database schema changes make this version incompatible with version 1.2 an earlier. Existing databases will need to be re-loaded. ensemblVEP ---------- Changes in version 1.4.0: NEW FEATURES - VEPParam is now VIRTUAL with subclasses VECParam67 and VEPParam73 - Add helpers currentVEP() and supportedVEP() - Add VEPParam75 class MODIFICATIONS - Modify VEPParam to support API versions 67 and 73 - Add slots 'scriptPath' and 'version' to VEPParam - New man page for runtime options - Update biocViews terms FGNet ----- Changes in version 2.0: NEW FEATURES - The networks can now be plotted for terms in addition to genes. - In the report, clicking on the plots allows to see the plot at full size next to the terms table (if the screen resolution allows it). - ToMatrix(): Added arguments 'key' (to choose either genes or terms) and 'removeFiltered' terms. Renamed main argument (geneTermSets) to 'results'. - IntersectionNetwork() shows a warning if there is no intersection. Added argument 'plotAllMg' to allow choosing wether to plot unconnected metagroups or not. - FunctionalNetwork() changed the two main arguments to a single one, which is the raw output from toMatrix() (a list with names: c("metagroupsMatrix", "gtSetsMatrix", "filteredOut")). Added arguments: 'eColor' to provide the edges color, and 'weighted' to draw the edge width according to the number of shared gene-term sets. - Reports: Added argument 'downloadGOtree' to allow choosing wether to download the go term trees png (slower) or just provide the link to the web tool. BUG FIXES - functionalNetwork() now correctly writes either "cl" or "mg" in the legend Changes in version 1.3.1: NEW FEATURES - adjMatrix() has been renamed to toMatrix() - GO png trees are now automatically downloaded when generating the report - functionalNetwork: metagroup/cluster legend order has been changed to alphabetical BUG FIXES - Minor bug fixes flipflop -------- Changes in version 1.1.6: NEW FEATURES - Add 'expected.counts' in the output objects. It gives the expected raw count (ie number of mapped fragments) for each predicted transcripts. This information is also available in the output gtf file. Changes in version 1.1.4: NEW FEATURES - Add a 'OnlyPreprocess' option for performing only the pre-processing step of the input sam file. This step writes two files: one file named 'prefix.instance' and one other named 'prefix.totalnumread', where 'prefix' is the prefix of the input sam file. The 'prefix.instance' file can then be given to the option 'preprocess.instance' and the total number of mapped reads is stored in the 'prefix.totalnumread' file. - Allow to give 'NN' (total number of mapped fragments) even when using the sam file as input. This can be used to run flipflop in parallel on parsed sam files with the same NN constant. USER-LEVEL CHANGES - Handle '~' in input paths with path.expand function. - Give a more detailed R output with the read count. MINOR CHANGES - Do not write individual Coverage into the pre-processing file anymore ie, the .instance file. (in practice comments lines in readgroup.cpp, part 'toStream') Changes in version 1.1.2: BUG FIXES - Switch from GRangeList to a regular list as the number of metadata columns could not vary in GRangeList. fmcsR ----- Changes in version 1.6.0: NEW FEATURES - Added timeout option - Allow parallel execution for batch computations FRGEpistasis ------------ Changes in version 0.99.5: - Added FDR control Changes in version 0.99.4: - Completed the man pages - Added the NEWS file - Updated the DESCRIPTION file - Completed the vignette - Updated the genotype file format Changes in version 0.99.3: - Corrected the biocViews Changes in version 0.99.1: - Added FRGEpistasis vignette gage ---- Changes in version 2.12.1: - remove pathview from the imports list for easier installation and loading. gCMAP ----- Changes in version 1.7.2: - CHANGE: Helper functions KEGG2cmap, reactome2cmap, wiki2cmap and go2cmap have two additional parameters, min.size and max.size, restricting the output to gene sets containing members within the specified range. - CHANGE: Method camera_score now outputs correlations in column 'effect'. - BUGFIX: Correct numbers of annotated genes are now returned for each set. Changes in version 1.7.1: - CHANGE: Vignettes are now stored in vignettes directory. gCMAPWeb -------- Changes in version 1.3.2: - BUGFIXMoved the 'Rook' package from 'Imports' to 'Depends' Changes in version 1.3.1: - CHANGEVignettes are now stored in vignettes directory. geNetClassifier --------------- Changes in version 1.3.1: NEW FEATURES - plotAssignments: Optimized speed and changed background color to blue. Added argument pointSize. - plotExpressionProfiles: Added argument sampleColors. BUG FIXES - Added RUnit and BiocGenerics to "Suggests" to avoid R CHECK warnings - Import methods, ebarrays and emfit in namespace to avoid R CHECK warnings - plot.GenesNetwork is now completelly equivalent to plotNetwork (same default arguments) GenomeInfoDb ------------ Changes in version 0.99.14: SIGNIFICANT USER-VISIBLE CHANGES - rename: package: Seqnames --> GenomeInfoDb supportedStyles -> genomeStyles makeSeqnameIds --> rankSeqlevels (add to export) seqnamesOrder --> orderSeqlevels extractSeqnameSet -> extractSeqlevels extractSeqnameSetByGroup -> extractSeqlevelsByGroup findSequenceRenamingMaps --> mapSeqlevels seqnamesInGroup --> seqlevelsInGroup seqnamesStyle --> seqlevelsStyle "seqnameStyle<-" --> "seqlevelsStyle<-" Changes in version 0.99.7: SIGNIFICANT USER-VISIBLE CHANGES - rename: isSupportedSeqnames -> .isSupportedSeqnames supportedSeqnameStyles -> .supportedSeqnameStyles supportedSeqnameMappings -> .supportedSeqnameMappings isSupportedSeqnamesStyle -> .isSupportedSeqnamesStyle Changes in version 0.99.6: NEW FEATURES - add new functions() seqnamesInGroup which will take a character vector of chromosomes and return the chromosomes specified by the group parameter supplied by the user. The user can also give the species and the style. seqnamesOrder() internally calls Herve's function makeSeqnameIds() - add seqnameStyles generic and method from GenomicRanges SIGNIFICANT USER-VISIBLE CHANGES - rename: testSeqnames -> isSupportedSeqnames - move SeqnamesStyle generic from GenomicRanges and define a new method which works on a character vector. DEPRECATED AND DEFUNCT - deprecate listAllSupportedStylesBySpecies(), listAllSupportedSeqnameStyles(), supportedOrganisms() supportedSeqnameMappingsWithGroup() DEPRECATED AND USED INTERNALLY(NOT EXPORTED - deprecate supportedSeqnameMappings(), supportedSeqnameStyles(), isSupportedSeqnamesStyle(),issupportedSeqnames() Changes in version 0.99.1: SIGNIFICANT USER-VISIBLE CHANGES - The Seqnames package will have functions which will be moved from AnnotationDbi , GenomicRanges - List of 9 functions moved from AnnotationDbi supportedSeqnameMappings, findSequenceRenamingMaps, supportedSeqnameStyles, supportedSeqnames, extractSeqnameSet, testSeqnames, isSupportedSeqnamesStyle, listAllSupportedStylesBySpecies, listAllSupportedSeqnameStyles. - makeSeqnameIds moved from GenomicRanges - keepStandardChromosomes moved from GenomicRanges - rename: keepStandardChromosomes -> keepChromosomes NEW FEATURES - added new functions: supportedOrganisms() supportedSeqnameMappingsWithGroup() extractSeqnameSetByGroup() GenomicAlignments ----------------- Changes in version 0.99: NEW FEATURES - coverage,BamFile-method uses yieldSize to iterate through large files. - coverage,character-method calculates coverage from a BAM file. GenomicFiles ------------ Changes in version 1.0.0: NEW FEATURES - First release of GenomicFiles package GenomicRanges ------------- Changes in version 1.16.0: NEW FEATURES - Add "subset" method for SummarizedExperiment objects. - Allow DataFrame in SummarizedExperiment assays. - Add 'use.mcols' arg (FALSE by default) to the granges(), grglist(), and rglist() generics (a.k.a. the range-squeezer generics). - Add coercion method from GRangesList to RangesList. - Add score() setter for GRangesList objects. - findOverlaps(..., type="within") now works on circular chromosomes. - Add 'ignore.strand' arg to "sort" method for GRanges objects. - Support subsetting of a named list-like object *by* a GenomicRanges subscript. - Support sort(granges, by = ~ score), i.e., a formula-based interface for sorting by the mcols. SIGNIFICANT USER-LEVEL CHANGES - Move many functionalities to the new GenomicAlignments package: - The GAlignments, GAlignmentPairs, and GAlignmentsList classes. - The qnarrow() generic and methods. - The "narrow" and "pintersect" methods for GAlignments and GAlignmentsList objects. - The low-level CIGAR utilities. - The "findOverlaps" methods for GAlignment* objects. - The summarizeOverlaps() generic and methods, and the "Counting reads with summarizeOverlaps" vignette. - findCompatibleOverlaps() and countCompatibleOverlaps(). - The findSpliceOverlaps() generic and methods. - The "overlap encodings" stuff i.e. the "encodeOverlaps" method for GRangesList objects, flipQuery(), selectEncodingWithCompatibleStrand(), isCompatibleWithSplicing(), isCompatibleWithSkippedExons(), extractSteppedExonRanks(), extractSpannedExonRanks(), extractSkippedExonRanks(), and extractQueryStartInTranscript(), and the "OverlapEncodings" vignette. - Rename 'with.mapping' arg -> 'with.revmap' in "reduce" methods. The old arg name is still working but deprecated. - Move makeSeqnameIds() function to the new GenomeInfoDb package and rename it rankSeqlevels(). The old name is still working but deprecated. - The "strand" methods now perform stricter checking and are guaranteed to always return a factor (or factor-Rle) with the "standard strand levels" and no NAs. Or to fail. BUG FIXES - Tweaks and fixes to various "strand" methods: - Methods for character vectors and factors do not accept NAs anymore (they raise an error). - Methods for integer and logical vectors map NAs to * (instead of NA). - Method for Rle objects now also works on character-, factor-, and integer-Rle objects (in addition to logical-Rle objects). genoset ------- Changes in version 1.16.0: NEW FEATURES - cn2lr now has methods for vector, matrix, and DataFrame (of Rle) and allows you to center your log2ratio values on 2 copies, or on a specified 'ploidy' for your sample. DEPRECATED AND DEFUNCT - The BAFSet and CNSet classes have moved from deprecated to defunct. These classes only added getter/setter methods for baf/lrr/cn. Since these only cover some possible assayDataElements, it is better to use x[i,j,k], where k is the name of an assayDataElement. - All RangedData-related things have now progressed to defunct. Please use GRanges for locData and everywhere else. Since the genoset package provides a common API for GenoSet, GRanges, and RangedData, I hope this will be a simple change for everyone. - sampleNames and featureNames are now *un-deprecated*. Feel free to use them. They just call colnames and rownames, respectively. I have defined my own rownames and colnames functions. The eSet ones seem to do a lot of extra work, and the getter versions read from the first assayDataElement, rather than pData and fData. I changed to the latter, so BigMatrix assayDataElements will remain untouched until you really mean to access them. GGBase ------ Changes in version 3.25.1: - plot_EvG will, for probeId() first argument, attempt to translate to gene symbol for y axis labeling GGtools ------- Changes in version 4.11: - appraise and calfig are provided to foster evaluation of eQTL-based GWAS hit predictions - cisAssoc has been added to obtain assay data from SummarizedExperiment and variants from VCF - CisConfig instances keepMapCache now defaults to TRUE - for naming symmetry we now have cisScores and transScores operating on CisConfig and TransConfig instances respectively - Added transeqByCluster() for nested concurrency for trans searches - Added TransConfig class to control trans searches, and modified transScores accordingly - Added hmm878, chromatin map of GM12878 for assessment of chromatin state enrichments - Added gffprocess(), of use when All.cis is used to generate chunk- specific gff3: gffprocess uses external sort/grep/tabix to unify the chunks into a single tabix- indexed gff3 - pifdr() has been changed to avoid approximation on a grid and to compute binning of permuted scores more rapidly using hist(); old behavior recoverable with legacy=TRUE - ciseqByCluster() uses nested concurrency to perform cis searches gmapR ----- Changes in version 1.6.0: NEW FEATURES - Add median distance from nearest end (MDFNE) statistics to output of variantSummary. - Updated GSNAP, which is orders of magnitude faster than the previous version, brings many fixes and offers many new features. One new feature is the clip_overlap argument, which clips overlapping ends of read pairs (important for variant calling). - Updated bam_tally, which is faster and includes support for counting in soft-clipped regions. USER-VISIBLE CHANGES - Changes to tallyVariant statistics: drop the unique read position counts; renamed count.pos/count.neg to count.plus/count.minus (way better names) - tallyVariants does a better job of carrying over the Seqinfo from the BAM file. GOSemSim -------- Changes in version 1.21.3: - fixed minor bug in combineMethods <2013-12-16, Mon> graphite -------- Changes in version 1.9.4 (2014-04-04): - Updated Biocarta, KEGG, NCI and Reactome data. - New databases: HumanCyc and Panther. Gviz ---- Changes in version 1.8.0: NEW FEATURES - The new HighlightTrack class to add a comon highlighting region for multiple tracks. - The new OverlayTrack class to merge the panels of multiple tracks into a single panel. - The reverseStrand display parameter lets you plot the data relative to the negative strand. - The just.label display parameter adds control to the placement of group labls in AnnotationTrack and GeneRegionTrack objects. - The box.legend display parameter to add a box around the legend in a DataTrack object. - extend.right and extend.left now also take relative expansion factors (as values between -1 and 1). - A new shape type fixedArrow for AnnotationTrack and GeneRegionTrack objects, and the arrowHeadWidth and arrowHeadMaxWidth parameters to better control the arrow shapes. - Display parameter schemes to persistently modify parameter settings. - The new featureAnnotation and groupAnnotation parameters to better control the feature and group labels in AnnotationTracks. - The new exonAnnotation and transcriptAnnotation parameters to better control the exon and transcript labels in GeneRegionTracks. - The new AlignmentsTrack class to visualized aligned NGS reads in a BAM file. BUG FIXES - A number of significant fixes. SIGNIFICANT USER-VISIBLE CHANGES - Some display parameter names have been reworked, but the old ones should still work as aliases. - Overplotting in AnnotationTrack and GeneRegionTrack objects has been minimized to be able to make better use of alpha blending. Also the way composite exons (e.g. part UTR, part CDS) are plotted has been changed. Those will now be merged into one feature as long as the exon identifier is identical and if they can be reduced into a single range wit min.gapwidth=1. gwascat ------- Changes in version 1.7.6: USER VISIBLE CHANGES - bindcadd_snv has been added to bind CADD scores of Kircher et al. 2014 for SNVs to any GRanges query Changes in version 1.7.1: USER VISIBLE CHANGES - gwrngs is now serialized and explicitly made available in global workspace on attachment - gwcat data.frame is not generated on attachment CHANGES PRIOR TO VERSION 1.7.1 - May 30 2012 -- improve makeCurrentGwascat to handle chrX and p.Value suitably GWASTools --------- Changes in version 1.9.9: - added block size support for GDS files stored with scan,snp dimensions - gdsSubset and gdsSubsetCheck now operate on the fastest dimension of the GDS file Changes in version 1.9.8: - updates/bug fixes to gdsSubset/gdsSubsetCheck - different missing value attributes may be set if sub.storage type is different. Changes in version 1.9.7: - Added gdsSubset and gdsSubsetCheck functions to make a subset GDS file that includes only specified SNPs and scans from an existing GDS file - Updated gdsImputedDosage and gdsCheckImputedDosage to account for IMPUTE2 gprobs files that have missing values (specified by three equal probability strings) - Updated gdsCheckImputedDosage to produce optional logfile reporting any missing genotypes Changes in version 1.9.6: - Revised anomFilterBAF - fewer centromere spanning anomalies that aren't real, corrects some merging issues (previously it would merge sections that really were different split widths). Users should be aware that this will increase running time. Changes in version 1.9.5: - Remove defunct functions. - Improve efficiency of gwasExactHW, mendelErr, assocTestRegression (reduce number of calls to rbind). Changes in version 1.9.4: - Bug fix in getChromosome method for SnpAnnotationDataFrame (proper behavior of unnamed "index" argument). Changes in version 1.9.3: - Added gdsImputedDosage function. - GdsGenotypeReader can return transposed genotypes. Changes in version 1.9.2: - ScanAnnotationDataFrame and ScanAnnotationSQLite allow non-integer scanID. - Fix getAlleleA and getAlleleB in GdsGenotypeReader to work with indels. Changes in version 1.9.1: - Documentation now located in vignettes/ folder. - Added ibdAssignRelationshipsKing. - Added support for genotype GDS files with scan x snp dimensions in GdsGenotypeReader. HiTC ---- Changes in version 1.7.11: NEW FEATURES - Update NAMESPACE for BioC 2.14 BUG FIXES - Fix a bug in the getRestrictionSitesPerChromosome and matchPattern function (fixed=TRUE). If FALSE, all 'N' are reported. Changes in version 1.7.5: NEW FEATURES - Update for BioC 2.14 SIGNIFICANT USER-VISIBLE CHANGES - Add fit.out parameter in the plotIntraDist to remove the outliers during the regression Changes in version 1.7.4: SIGNIFICANT USER-VISIBLE CHANGES - New parameter for normICE - spars.filter, to filter out the more sparse bins before normlization - Change the parameters of getAnnotatedRestrictionSites and setGenomicFeatures functions - Update of the setGenomicAnnotation function to fit with the original HiCNorm method BUG FIXES - isSymmetrix - NA values - Bug in definition of upstream and downstream flanking region for a restriction site in getAnnotatedRestrictionSites Changes in version 1.7.3: NEW FEATURES - Add new normalization method for Hi-C data from Hu et al (HiCNorm). This method is based on linear regression model between interaction counts and sources of bias such as GC content, mappability, fragment length, etc. See normLGF(), setGenomicFeatures(), getAnnotatedRestrictionSites(). - Add new normalization method for Hi-C data from Imakaev et al.(ICE). The ICE procedure is an iterative normalization method used to remove any bias from HiC data. - Add 'summary' method for HTCexp and HTClist objects SIGNIFICANT USER-VISIBLE CHANGES - Improve quality control methods based using sparse data - Change method option for normPerTrans methods. The 'mean' method is in fact a 'max' method - Update of the export.my5C list format BUG FIXES - max (na.rm=TRUE) in mapC function HTSeqGenie ---------- Changes in version 3.13.13: - removed the "no job lefts" tests in test.sclapply() Changes in version 3.13.12: - now uses TP53Which() (instead of which.rds) for variant calling tests - now builds in BioC Changes in version 3.13.11: - now use TxDb.Hsapiens.UCSC.hg19.knownGene's version number in the TP53 genomic feature cache file, to avoid bugs when updating TxDb.Hsapiens.UCSC.hg19.knownGene Changes in version 3.13.10: - added an optional which config to limit VariantTools variant calling to certain regions Changes in version 3.13.9: - NA Changes in version 3.13.8: - fixed the "as.vector(x, mode) : invalid 'mode' argument" bug by adding the "importFrom(BiocGenerics,table)" NAMESPACE directive Changes in version 3.13.7: - enable indelRealigner in runPipeline controlled by config value of alignReads.do Changes in version 3.13.6: - set gatk.path in options if GATK_PATH env is set to an existing file. This is mostly for allowing the unit tests to know if and where a GATK is installed Changes in version 3.13.5: - require bamtally bugfixed version of gmapR Changes in version 3.13.4: - fixed bug in generateCountFeaturesPlots() when no genes left after filtering. Practically only happens for bacterial or viral genomes when every gene is hit more than 200 times Changes in version 3.13.3: - now saving fragmentLength in summary_coverage.txt - using Jinfeng's weighted mean to estimate fragmentLength - removed the parallelization in saveCoverage (since saveCoverage is used in parallel) Changes in version 3.13.2: - activate read trimming for illumina 1.5 quality using the 'B' as qual indicator Changes in version 3.13.1: - deactived the unit tests (test.wrap.callVariants, test.wrap.callVariants.parallel, test.wrap.callVariants.rmsk_dbsnp) until VariantAnnotation is fixed, to be able to compile HTSeqGenie on BioC servers Changes in version 3.13.0: - change to new dev cycle version number HTSFilter --------- Changes in version 1.2.1: - -- Minor bug fix for integeration in DESeq2 pipeline (which now has automatic independent filtering available) -- HTSFilter now accepts data with multi-factor designs for all input types illuminaio ---------- Changes in version 0.6.0 (2014-04-11): - The version number was bumped for the Bioconductor release version, which is now BioC v2.14 for R (>= 3.1.0). Changes in version 0.5.6 (2014-03-10): - Added a CITATION file, cf. citation("illuminaio"). Changes in version 0.5.5 (2014-01-19): - Added support for encrypted IDAT files where not all data fields are of the same length e.g. HumanHap550 v1. Changes in version 0.5.2 (2013-11-05): - moved testData to IlluminaDataTestFiles. - Added unitTests for encrypted IDATs. Changes in version 0.5.1 (2013-11-04): - Resshuffled internal code in readIDAT_nonenc so that seek() is always forward based. Changes in version 0.5.0: - The version number was bumped for the Bioconductor devel version. - No updates. inSilicoDb ---------- Changes in version 2.0.0: NEW FEATURES - Ability to access InSilico MySafe - New methods make it now possible to check the accessibility of data - Better integration of curated data - Possibility to use SCAN and UPC normalizations OTHER - Changes in the API, check the documentation for more information inSilicoMerging --------------- Changes in version 1.8.0: NEW FEATURES - Possibility to use named lists instead of eSets, check the merge- method documentation for an example BUG FIXES - Measurements are now always sorted in the same order in phenoData and exprs OTHER - Previous "NONE" method only available when not specifying a batch effect removal method or by specifying NULL. intansv ------- Changes in version 1.2.1: Notes - Add support to SV prediction programs Lumpy and softSearch. - Modify methodsMerge to make it more robust. - Modify all the read functions to coordinate methodsMerge. isobar ------ Changes in version 1.9.3: - allow the use of a combination matrix in NoiseModel reporterTagNames - added function getProteinInfoFromTheInternet which automatically recognizes Uniprot and Entrez ACs. Set now as default 'protein.info.f' in the report configuration. - Overhauled isobar-analysis.Rnw - use of ltxtables to allow optimal column widths (longer runtime, however) - use [[ instead of for accession of lists - better column and grouping description - allow report generation without a proteinInfo object - set report cache directory to 'cache' (instead of '.') by default - 1.9.3.2: - mascotParser2.pl: allow to skip modif-conversion with -no-modiconv - mascotParser2.pl: set --lightXML as default - report generation: set combn.method="versus.channel", which computes the ratios against the first channel - various PDF report improvements - 1.9.3.3: - report tables are written into tables which are loaded with LTxtable report generation takes longer now - fixes in correct.peptide.ratios - use combined protein group for peptide-protein mapping - use only reporter proteins for mapping - fix in creation of protein groups from template, subset by peptide _and_ modif Changes in version 1.9.2: - fix issue of NA in 'n.spectra' when calculating summarized ratios - various report improvements: - use column of variable width to display class labels - add attributes of quant table to summarized result table - improved placement of tikz peptide group pictures KEGGgraph --------- Changes in version 1.21.1 (2013-10-17): BUG FIXES - mergeKEGGgraph can handle NULL objects now - KEGGpathway2Graph eliminates duplicated edges so that parseKGML2DataFrame does not fail. (Thanks to Paul Shannon's bug report) - Paul Shannon added a set of RUnit tests to KEGGgraph limma ----- Changes in version 3.20.0: - New functions diffSplice(), topSplice() and plotSplice() provide functionality to analyse differential splicing using exon-level expression data from either microarrays or RNA-seq. - New Pasilla case study added to User's Guide, demonstrating differential splicing analysis of RNA-seq data. - new function weightedLowess() which fits a lowess curve with prior weights. Unlike previous implementations of lowess or loess, the weights are used in calculating which neighbouring points to include in each local regression as well as in the local regression itself. - weightedLoess() now becomes the default method used by loessFit() to fit the loess curve when there are weights. The previous locfit and loess() methods are offered as options. - linear model fit functions lm.series(), mrlm.series() and gls.series() no longer drop the dimensions of the components of the fitted object when there is just coefficient or just one gene. Previously this was done inconsistently in some cases but not others. Now the matrix components always keep dimensions. - The functions lmFit(), eBayes() and tmixture.vector() now work even when there is just one gene (one row of data). - New function subsetListOfArrays(), which is used to simplify the subsetting code for RGList, MAList, EList, EListRaw and MArrayLM objects. - new function tricubeMovingAverage() for smoothing a time series. - barcodeplot() has a new option to add enrichment worms to the plot, making use of tricubeMovingAverage(). - New plot() methods for RGList, MAList, EList and MArrayLM class objects. In each case, this produces a similar result to plotMA(). When using plot() or plotMA() on an MArrayLM object, the column is now specified by the 'coef' argument instead of by 'array'. - plotMA3by2() now works on single channel data objects as well as on MAList objects. - New function read.idat() to read files from Illumina expression beadarrays in IDAT format. - The ctrlpath argument of read.ilmn() now defaults to the same as path for regular probes. This means that only one path setting is required if the regular and control probe profiles are in the same directory. - read.ilmn() now sets the same probe IDs as rownames for both the expression matrix E and the annotation data.frame genes, providing that the probe IDs are unique. - beadCountWeights() can now work with either probe-wise standard errors or probe-wise standard deviations. - treat() has new arguments robust and winsor.tail.p which are passed through to robust empirical Bayes estimation. - topTreat() now includes ... argument which is passed to topTable(). - topTable() with confint=TRUE now produces confidence intervals based on the t-distribution instead of on the normal distribution. It also now accepts a numeric value for the confint argument to specify a confidence level other the default of 0.95. - topTable() will now work on an MArrayLM fit object that is missing the lods component, for example as produced by treat(). - roast() and mroast() now permit array weights and observation weights to both be specified. - camera(), roast() and mroast() now use getEAWP() to interpret the data object. This means that they now work on any class of data object that lmFit() will. - romer() now uses propTrueNull(method="lfdr") instead of convest(). This makes it substantially faster when the number of genes is large. - genas() now uses fit\$df.total from the MArrayLM object. This prevents df.total from exceeding the total pooled residual df for the dataset. The genas() results will change slightly for datasets for which df.prior was very lage. - plotDensities() is now an S3 generic function with methods for RGList, MAList, EListRaw and EList objects. - plotFB is now an S3 generic function with methods for RGList and EList data objects. - New topic help pages 10GeneSetTests.Rd and 11RNAseq.Rd. The page 10Other.Rd is deleted. All topic help pages are now listed under 'See also' in the package introduction page accessible by ?limma. - avereps() was never intended to be applied to RGList or EListRaw objects. It now gives an error when applied to these objects instead of returning a matrix of questionable value. - Bug fix: fitFDistRobustly() was failing when there were missing values or zero df values and covariate was NULL. - Bug fix: vennDiagram() wasn't passing extra arguments (...) to plot() when the number of sets was greater than 3. - Bug fix to topTreat(). Rownames were incorrectly ordered when p<1. - bug fix to genas(), which was not handling vector df.prior correctly when the fit object was generated using robust=TRUE. - bug fix to squeezeVar(). Previously there was an error when robust=TRUE and trend=FALSE and some of the estimated df.prior were infinite. - bug fix to topTable() and topTableF() when sorting by F-statistic combined with p-value or lfc cutoffs. metagenomeSeq ------------- Changes in version 1.5 (2014-04-17): - Incorporating biom-format support with the biom2MRexperiment, MRexperiment2biom and load_biome function. - Added uniqueFeatures, filterData, aggregateByTaxonomy / aggTax, plotFeature and calculateEffectiveSamples functions. - Renamed MRfisher to fitPA (presence-absence fisher test). - Added warnings for normalization - Added fitDO (Discovery odds ratio test) and fitMeta (original metastats). - Added match.call() info to fitZig output - Fixed missing E-Step bounds metaMS ------ Changes in version 0.99.8: - fixed documentation for previous fix... Changes in version 0.99.7: - fixed incomplete GC settings Changes in version 0.99.6: - replaced paste(..., "/") with file.path() in runLC.Rnw metaseqR -------- Changes in version 1.0.0 (2014-04-11): NEW FEATURES - Function to calculate the F1-score (or harmonic mean of precision and recall) - Mature and tested enough to go from 0.x.y version to 1.0.0 Changes in version 0.99.6 (2014-04-09): NEW FEATURES - Example on how to estimate statistical test weights in the vignette BUG FIXES - Bug when exporting flags when gene or exon filters are NULL Changes in version 0.99.5 (2014-03-31): NEW FEATURES - Changed directory structure of the report to look more organized and pro - Added the ability to save and retrieve the gene model counts list (counts for each exon) in an .RData file to be reused in another analysis later, as summarizing genes is one of the most time-consuming parts. BUG FIXES - Minor problems with the report Changes in version 0.99.4 (2014-03-18): BUG FIXES - Removed all <<- assignments - Changed the Depends of DESCRIPTION file to import less packages in the main environment - Added qvalue package to Depends as there was a problem with NBPSeq Changes in version 0.99.3 (2014-03-17): NEW FEATURES - Function to check and warn if a main metaseqr argument is invalid (may prevent crashes during run) BUG FIXES - Small bug fix in read2count function Changes in version 0.99.2 (2014-03-14): NEW FEATURES - Ability to display only the top x% of significant genes to avoid excessively big reports BUG FIXES - More code and codestyle changes to comply with Bioconductor's guidelines Changes in version 0.99.1 (2014-03-12): NEW FEATURES - Ability to export counts table (raw and normalized) when reading from BAM files or just normalized otherwise - Valid examples for many functions BUG FIXES - More code and codestyle changes to comply with Bioconductor's guidelines Changes in version 0.99.0 (2014-02-21): NEW FEATURES - Support for Pan troglodytes - Improved the simulator to i) simulate length bias and ii) better length selection BUG FIXES - Code changes to comply with Bioconductor's guidelines Changes in version 0.93.0 (2014-02-12): NEW FEATURES - Support for Arabidopsis thaliana - Additional validation functions BUG FIXES - Bugs affecting multilevel factorial analysis (single factor, more than two conditions) - Smaller bug fixes Changes in version 0.92.0 (2014-01-25): NEW FEATURES - Functions to estimate weights for combining p-values based on simulated datasets from real data BUG FIXES - Smaller bug fixes Changes in version 0.91.0 (2014-01-03): NEW FEATURES - Functions to create simulated datasets - Functions to create false discovery and ROC curves BUG FIXES - A bug in p-value vector naming causing unordered p-values for limma and baySeq when combining methods - Smaller bug fixes Changes in version 0.9.1 (2013-11-27): NEW FEATURES - Permutation methods for combining p-values from multiple statistics - More interactive and compact report BUG FIXES - A bug in exon filters resulting in removing genes/transcripts with only one exon - A serious bug in exon filters causing wrong genes to be filtered out under circumstances Changes in version 0.9.0 (2013-11-21): NEW FEATURES - First release MIMOSA ------ Changes in version 0.99.2: - Added unit tests - Passing BiocCheck - Remove dependency on multicore. Now parallel only. Changes in version 0.9.12: - MIMOSA now returns a MIMOSAResultList S3 class. A lightweight wrapper for a list, with methods defined to extract the fdr and pData, getW, and getZ to extract the component weights and posterior probabilities, respectively. - print for MIMOSAResult and MIMOSAResultList - extractors for countsTable, the table of counts used to fit the model. Takes an argument to return the proportions or the counts. - MIMOSA checks throws a more informative warning if the data is filtered into oblivion when not properly paired (e.g. when the user doesn't aggregate over replicate negative controls, for example. ) - volcanoPlot implemented for MIMOSAResultList - Cleaned up package warnings and notes. - Cleaned up imports and depends. Changes in version 0.9.9: - Bug Fixes ** Filtered out empty categories on the conditioning variables. ** Support for parallel as well as multicore - News ** multicore support (via the multicore package) will be phased out in favor of the parallel package. Changes in version 0.8.0: - Model fitting via the 'MIMOSA' function - Data represented via an ExpressionSet - Formula interface support - Removed old code, including ICS class, and dependencies upon it. - New documentation Changes in version 0.7.0: - First beta release of MIMOSA - model fitting via MCMC through the .fitMCMC function minfi ----- Changes in version 1.9: - Importing the changes from 1.8 into 1.9. - Added the withColor argument to the getProbeType function, which allows the return of "IGrn", "IRed", "II", instead of only "I", "II". - Added asList argument to getControlAddress to return result as a list. - Moved reshape from Depends to Imports. - Dramatic improvement in memory usage of preprocessRaw. - Updated CITATION, the minif paper is in press. - Fixed bug with mapToGenome(..., mergeManifest = TRUE) reported by Dale Watkins <dale.watkins at="" sahmri.com=""> and Allegra A. Petti <apetti at="" genome.wustl.edu="">. - Fixed bug with mapToGenome(rSet) with rSet being a RatioSet with the CN set to NULL reported byAllegra A. Petti <apetti at="" genome.wustl.edu="">. - Added preprocessFunnorm, a new preprocessing method. - Improvements to the speed of getAnnotation by Martin Morgan <mtmorgan at="" fhcrc.org="">. MotifDb ------- Changes in version 1.5.9: NEW FEATURES - JASPAR_2014 added, with 592 motifs motifStack ---------- Changes in version 1.7.7: NEW FEATURES - No changes classified as 'new features' (package under active development) - add ic.scale parameter to plotMotifLogo. BUG FIXES - Fix bugs for motifSignature when the distance is larger than maximal distance. - No changes classified as 'bug fixes' (package under active development) Changes in version 1.7.6: NEW FEATURES - Change the class of signature to include the color sets. BUG FIXES - Allow motifSignature to accept Non-Binary Trees. Changes in version 1.7.5: NEW FEATURES - Change the output of motifStack for further steps. BUG FIXES - No changes classified as 'bug fixes' (package under active development) Changes in version 1.7.3: NEW FEATURES - Change the output of readPCM from a matrix to a list of pcm objects. BUG FIXES - No changes classified as 'bug fixes' (package under active development) Changes in version 1.7.2: NEW FEATURES - No changes classified as 'new features' (package under active development) BUG FIXES - fix the bugs of changing plot layout when using plotMotifLogoStackWithTree Changes in version 1.7.1: NEW FEATURES - No changes classified as 'new features' (package under active development) BUG FIXES - fix the bugs of leave names and plot region MSnbase ------- Changes in version 1.11.14: - update dependency to R >= 3.1 [2014-04-05 Sat] Changes in version 1.11.13: - Document [get|grep]Ecols in io vignette [2014-03-31 Mon] - typo in readMSnSet man [2014-03-31 Mon] - updated affiliation in vignettes [2014-03-31 Mon] Changes in version 1.11.12: - Fixed a bug in readMzTabData reported by Hendrik Weisser [2014-03-26 Wed] Changes in version 1.11.11: - precomputed msx test data now has id data [2014-03-25 Tue] - quantitation unit tests [2014-03-25 Tue] - quantify method now accepts label-free methods [2014-03-25 Tue] Changes in version 1.11.10: - import mzID [2014-03-20 Thu] - dummyiTRAQ id extdata [2014-03-21 Fri] - add addIdentificationData method for MSnExp and MSnSet [2014-03-21 Fri] - using data from pRolocdata (was pRoloc) [2014-03-23 Sun] - added removeNoId,MSnExp,MSnSet methods [2014-03-23 Sun] - added idSummary,MSnExp,MSnSet methods [2014-03-24 Mon] - Not generating different sample per file when reading raw data. pData(.) now has systematically 1 row if not specifically provided by the user. A message is also reported by validity,pSet if row(pData(.)) > 1. [2014-03-24 Mon] - NAnnotatedDataFrame now has default multiplex 1 [2014-03-25 Tue] - NAnnotatedDataFrame unit tests [2014-03-25 Tue] Changes in version 1.11.9: - write.exprs can have fDataCol or fcol (for consistence) [2014-03-17 Mon] - Fixing bug in combineFeatures(..., is.character(groupBy)) [2014-03-19 Wed] - fixed combineFeatures [2014-03-20 Thu] - added example, test and doc for combineFeatures with list [2014-03-20 Thu] Changes in version 1.11.8: - adding redundancy handling to combineFeatures (by vladpetyuk, pull request #18) [2014-03-14 Fri] - updated combineFeatures signature to accomodate above changes [2014-03-14 Fri] - updated unit tests for new testhat 0.8 [2014-03-14 Fri] Changes in version 1.11.7: - NA Changes in version 1.11.6: - add corresponding xcms functions to the chromatogram and xic manual page [2014-02-21 Fri] - new bpca imputation methods [2014-02-27 Thu] - replacing stop_on_error with option in vignette [2014-02-27 Thu] Changes in version 1.11.5: - typo in MSnSet droplevels man [2014-01-27 Mon] - typo in MSnbase-demo vignette [2014-02-20 Thu] - fix BPI legend in chromatogram [2014-02-20 Thu] Changes in version 1.11.4: - passing ... to sweep when normalising [2013-12-08 Sun] - updated makeMTD to accomodate new MS ontology [2013-12-23 Mon] Changes in version 1.11.3: - updated mzTab example files to new url [2013-11-15 Fri] - warning about mzTab versions [2013-11-15 Fri] Changes in version 1.11.2: - move inst/doc to vignettes [2013-10-19 Sat] Changes in version 1.11.1: - document na.rm in combineFeatures Rd [2013-10-18 Fri] Changes in version 1.11.0: - New devel version for Bioc 2.14 MSstats ------- Changes in version 2.1.3: - fix the groupComparison for label-free experiments. - automatically generate progress report as .txt files - add progress message for groupComparison and dataProcessPlots function. Changes in version 2.1.1: - fix the bug in Condition plot : 1. for label-based : match reference and endogenous 2. for label-free : when there is one observation in each group, SD=NA. make it zero. - fix the bug in heatmap and comparison plots : remove NA result for plotting - fix the bug for label-free groupComparison : how to get subject_nested parameter in make.contrast.free for unequal number per group - fix the bug in group quantification : make.contrast.group.quantification fixed for subject_nested parameter mzID ---- Changes in version 1.1.6: - Added documentation Changes in version 1.1.5: - Now computes mzR compatible acquisitionNum for the scans (thanks to Sebastian Gibb) - Checks for existence of local files (thanks to Sebastian Gibb) - XML moved from depend to import Changes in version 1.1.4: - Now computes mzR compatible acquisitionNum for the scans (thanks to Sebastion Gibb) - Various bug fixes Changes in version 1.1.3: - Introducing the mzIDCollection class to handle multiple mzID objects Changes in version 1.1.2: - Added the possibility to create the different 'sub'classes of mzID directly from a file without first having an internal xml representation and namespace Changes in version 1.1.1: - Fixed bug where multiple names in the modification rules would crash the parsing. Multiple names gets collapsed with '/' mzR --- Changes in version 1.9.8: - Pointing to the relevant wiki page in the Rcpp compiler/linker warning [2014-04-03 Thu] Changes in version 1.9.7: - modify to new biocViews to DESCRIPTION file (s.arora) Changes in version 1.9.6: - import all of Rcpp to avoid warnings in reverse dependencies <2014-02-14 Fri> Changes in version 1.9.3: - fix a string in ramp.cpp to enable compilation on clang-3.4 Changes in version 1.9.2: - version bump for Rcpp 0.10.6 <2013-10-30 Wed> Changes in version 1.9.1: - moved vignettes to /vignettes <2013-10-17 Thu> nondetects ---------- Changes in version 0.99.2: BUG FIXES - Added informative NEWS file. - Added version information to DESCRIPTION file. Changes in version 0.99.1: BUG FIXES - Changes in coding style to make package consistent with Bioconductor. - New biocViews added to package. - Added importing of pData from Biobase package. - Added unit tests. Changes in version 0.99.0: - Package released. npGSEA ------ Changes in version 0.99.0: - Package submitted to Bioconductor (March 31 2014) pathview -------- Changes in version 1.3.6: - ajusted node x coordinate by +0.5 to better fit the color blocks in 2 layer native kegg views. Changes in version 1.3.4: - updated bods to included an extra column of id.type, the default gene ID type. Changes in version 1.2.4: - updated korg to included over 600 newly added species. Pathview can work with 2970 species now. - Make returned values from pathview, keggview.native and keggview.graph functions invisible. Changes in version 1.2.3: - Fixed bug in node.map function, which produces 0 values when all multiple genes in a node are NA's. Changes in version 1.2.2: - Fixed bug in mol.sum function, which generates "incorrect number of dimension" or NA's when sum.method="median" etc. Changes in version 1.2.1: - Fixed bug in "missing red disease gene node labels" in diease pathways. To avoid interfering with node coloring, set all disease gene labels to black instead. phyloseq -------- Changes in version 1.7.24: USER-VISIBLE CHANGES - Added support for [Partial] Constrained Analysis of Principal Coordinates (CAP). - A supported/documented option in ordinate, supported by plot_ordination. - This solves [Issue 312](https://github.com/joey711/phyloseq/issues/312). - The ordinate function now takes an explicit formula argument. - This facilitates reliable contrained ordination calls for: - CAP (this commit) - RDA (partial redundancy analysis) - CCA (constrained correspondence analysis) Changes in version 1.7.23: USER-VISIBLE CHANGES - Refactor plot_ordination to be more stable, error less and give informative warnings. - Expect no critical API changes. Some errors now informative warnings with useful auto-changes to parameters. - The type='biplot' option no longer hard-specifies a discrete color scale. Available default pallette should work. - For type='biplot', the non-variable (Taxa or Sample) label will always appear first in a discrete legend. Changes in version 1.7.22: USER-VISIBLE CHANGES - Revised psmelt to automatically modify data column-name conflicts, with warning - Udpated psmelt doc to formally notify users of these potential conflicts. - This solves Issue 307: https://github.com/joey711/phyloseq/issues/307 Changes in version 1.7.21: USER-VISIBLE CHANGES - Updated import_qiime doc to emphasize it is intended for legacy QIIME files. - Much faster and mem-efficient import of legacy QIIME and usearch files. - Uses data.table syntax to better manage import of large files. - Entire HMPv35 now imports in about 1 minute, low risk of mem-swap. - Added dependency to data.table Changes in version 1.7.20: USER-VISIBLE CHANGES - No user-visible changes. All future compatibility changes. BUG FIXES - Unit test changes to work with upcoming R release and new testthat version. Changes in version 1.7.19: USER-VISIBLE CHANGES - Documentation revisions. Faster examples, updated links. Changes in version 1.7.18: USER-VISIBLE CHANGES - Fix minor bug that prohibited parallel execution of weighted UniFrac Changes in version 1.7.17: USER-VISIBLE CHANGES - Added import_usearch_uc Added first-time support for usearch ?.uc? style output table. Addresses Issue 286, importing from UPARSE. https://github.com/joey711/phyloseq/issues/286 Further feedback on performance, use-cases, should be posted there. Changes in version 1.7.16: USER-VISIBLE CHANGES - Fixed minor bug affecting legend-order in plot_network Issue 288, https://github.com/joey711/phyloseq/issues/288 Changes in version 1.7.15: USER-VISIBLE CHANGES - tip_glom now uses standard R clustering tools, and takes their arguments documentation and tests updated to reflect the change much simpler, faster - merge_taxa now uses abundance to determine the achetype by default. Previously arbitrary. Changes in version 1.7.14: USER-VISIBLE CHANGES - Minor change in mixture model vignette, revised graphic Changes in version 1.7.13: USER-VISIBLE CHANGES - Deprecated originalUniFrac() internal function old (original) unifrac algorithm no longer supported. Addresses Issue 66: https://github.com/joey711/phyloseq/issues/66 Changes in version 1.7.12: USER-VISIBLE CHANGES - Formal deprecation of functions using .Deprecated Issue 269, https://github.com/joey711/phyloseq/issues/269 - Fixed bug in interface with vegan::fisher.alpha(..., se=TRUE). vegan doc states that this returns a data.frame, but a data.frame is not returned in vegan version 1.7.10. phyloseq no checks output dimensions before processing in estimate_richness - Replaced deprecated functions in tests and documentation. Changes in version 1.7.11: USER-VISIBLE CHANGES - Adds warning in make_network() and error in plot_network if empty graph encountered Issue 275, check/warning for empty igraph objects https://github.com/joey711/phyloseq/issues/275 - rarefy_even_depth() messages changed from cat() to messages(), and optional verbose argument added https://github.com/joey711/phyloseq/issues/263 Changes in version 1.7.10: USER-VISIBLE CHANGES - Fixes build-error originating from change in ade4 NAMESPACE in version 1.6.2 - Change minimum ade4 version to 1.6.2 - Uncommented examples now included in documentation for DPCoA function Changes in version 1.7.9: USER-VISIBLE CHANGES - Fixed typo-derived bug in new vignette. - These changes allow user to build from source without error. Changes in version 1.7.8: USER-VISIBLE CHANGES - Package dependencies reduced/clarified: https://github.com/joey711/phyloseq/issues/259 Should reduce chances for collisions with other packages, and related issues. Removed any dependencies on the picante package. - Replaced picante::node.age() with a faster implementation, node_ages() Appears to be 3 times faster. Speeds up UniFrac() and tip_glom() calculations. Changes in version 1.7.7: USER-VISIBLE CHANGES - Tree fixes: https://github.com/joey711/phyloseq/issues/235 https://github.com/joey711/phyloseq/issues/255 - If a tree has NA branch-length values, they are automatically set to 0. This occurs within both phyloseq(), and read_tree(). - UniFrac calculations require a rooted tree. While a rooted tree is not required to be part of a phyloseq object, it is a helpful default behavior to select a random root when UniFrac is called and the tree is unrooted, flashing a notice to the user. - Precise import from ape-package, rather than full-import. Smaller chance for collisions. Precisely-defined dependencies listed in NAMESPACE - As a result of the previous, phyloseq defines a placeholder "phylo" class, extended from "list". This seems to match the class from a full import of ape, and is necessary since ape does not export the "phylo" class. Changes in version 1.7.6: USER-VISIBLE CHANGES - Merged branches 1.7.4 and 1.7.5 Changes in version 1.7.5: NEW FEATURES - User-specified axis ordering to plot_heatmap() - User-specified axis edges to plot_heatmap() - This addresses: [Issue 237](https://github.com/joey711/phyloseq/issues/237) [Issue 230](https://github.com/joey711/phyloseq/issues/230) USER-VISIBLE CHANGES - New arguments to plot_heatmap(): taxa.order, sample.order, first.sample, first.taxa Changes in version 1.7.4: NEW FEATURES - import_mothur now handles more formats - Added documentation to discourage .group/.list formats Changes in version 1.7.3: NEW FEATURES - Added phyloseq_to_deseq2() wrapper function and examples for computing multiple OTU tests using Negative Binomial model and GLM (DESeq2). USER-VISIBLE CHANGES - Also added new .Rmd vignette for using DESeq, with colorectal carcinoma data Changes in version 1.7.2: USER-VISIBLE CHANGES - Reformat NEWS (this) file. Changes in version 1.7.1: USER-VISIBLE CHANGES - Rmd/HTML-based vignettes. No more Rnw/Sweave/PDF - Updated installer piano ----- Changes in version 1.4.0: NEW FEATURES - Added argument plot to consensusHeatmap() so that drawing the heatmap can be suppressed but the corresponding numerical matrix can be saved. - Added argument cellnote to consensusHeatmap() so that the information inside each cell of the heatmap can be chosen to be either the consensus scores (as previously), the median p-values, the number of genes or empty. - Added a matrix nGenesMat to the output of consensusHeatmap() containing the same information as printed in the heatmap if argument cellnote="nGenes". - Added arguments columnnames, colorkey, colorgrad and cex to consensusHeatmap() for better control of the column labels, toggling of the colorkey, color selection and text size. - Introduced the new function GSAheatmap(), which is similar to consensusHeatmap() but for only a single gene set result (gsaRes object). BUG FIXES - Fixed a bug which for some settings of runGSA would not output number of up- and downregulated genes in the gene sets. DOCUMENTATION - Updated consensusHeatmap() man page according to new changes in the function. - Added man page for GSAheatmap(). plethy ------ Changes in version 1.1.3: NEW FEATURES - Added 'summaryMeasures' method. - Added experimental heatmap-like plotting functionality 'plethy:::mvtsplot' procoil ------- Changes in version 1.13.2: - cleared up package dependencies and namespace - reference to Bioconductor Git-SVN bridge - minor corrections to vignette pRoloc ------ Changes in version 1.3.19: - fixed error introduced with mclust 4.3 (that now returns the data in the Mclust output - see comment in pRoloc:::gmmOutliers for details) [2014-04-07 Mon] Changes in version 1.3.18: - getPredictions can take class-specific scores [2014-04-04 Fri] Changes in version 1.3.17: - fixed newly introduced bug (see 1.3.16) in pRoloc:::subsetAsDataFrame - thank you unit tests for saving me, again [2014-03-26 Wed] Changes in version 1.3.16: - pRoloc:::subsetAsDataFrame now preserved original sample/column names [2014-03-24 Mon] - fixed wrong message when using col and pch in plot2D [2014-03-25 Tue] Changes in version 1.3.15: - updated pRolocmarkers("mmus") [2014-03-21 Fri] - moved extdata/*csv to pRolocdata [2014-03-23 Sun] - using *csv from pRolocdata [2014-03-23 Sun] Changes in version 1.3.14: - deleted tab character [2014-03-15 Sat] - added support for GMM parametrisation to phenoDisco [2014-03-17 Mon] - message instead of warning when using colour and pch [2014-03-21 Fri] - remove 1 duplicated mouse marker [2014-03-21 Fri] Changes in version 1.3.13: - fixed a bug in addLegend [2014-03-14 Fri] - updated testing to testthat 0.8 [2014-03-14 Fri] - Fixing several warnings about symnbols being replaced upon pRoloc loading and note about usage of ::: [2014-03-15 Sat] Changes in version 1.3.12: - added phenoDisco2 for testing, allows choice of GMM parameters [2014-02-26 Wed] - removed duplicated fly markers [2014-02-28 Fri] - updated affiliations in vignettes [2014-03-10 Mon] Changes in version 1.3.11: - modify to new biocViews to DESCRIPTION file by s.arora [2014-03-04] Changes in version 1.3.10: - new phenoDisco ndims argument to use more than two two principal components as input for discovery analysis [2014-01-03 Mon] - fixed and updated phenoDisco logging [2014-02-03 Mon] - added support for parallel phenoDisco execution. See BPPARAM argument [2014-02-03 Mon] - fixed issues with using PD and ndims [2014-02-10 Mon] - fixed call to anyUnknown in PD code [2014-02-10 Mon] - checking if duplicated markers in addMarkers [2014-02-14 Fri] Changes in version 1.3.9: - bump to force rebuild for new Rcpp Changes in version 1.3.8: - Removed trailing space in mmus nucleus markers [2014-01-21 Tue] - using filterNA to remove features with missing values in plot2D [2014-01-21 Tue] - fixed plot2D/addLegend [2014-01-23 Thu] Changes in version 1.3.7: - fixed addLegend to use correct colours (order) [2014-01-20 Mon] - fix typo in addMarkers man [2014-01-20 Mon] - re-arranged stockpch so that interleave full and empty plotting character [2014-01-20 Mon] 0 Removed last stockcol (tomato), too cose to "#FF7F00" [2014-01-20 Mon] Changes in version 1.3.6: - updated human markers: keep new pd.markers phenotypes, validated by Lisa and remove singletons [2014-01-14 Tue] - first stockpch is noe 19 [2014-01-16 Thu] - plot2D(.., pch) now taken into account for labelled data [2014-01-16 Thu] - removed alpha plot2D argument [2014-01-17 Fri] - updated plot2D and addLegend function with support for more organelle groups than colours. The previous versions are available as plot2D_v1 and addLegend_v1. [2014-01-17 Fri] Changes in version 1.3.5: - pRoloc citation [2014-01-12 Sun] Changes in version 1.3.4: - new unknownSet function [2013-12-11 Wed] - updated vignettes to account for tan2009r1 changes [2013-12-16 Mon] Changes in version 1.3.3: - update citation in phenoDisco.Rd [2013-11-22 Fri] - typos in vignettes [2013-11-25 Mon] Changes in version 1.3.2: - new markers [2013-11-06 Wed] - markers in vinette [2013-11-15 Fri] - mouse markers [2013-11-18 Mon] Changes in version 1.3.1: - using combineFeatures(..., na.rm=TRUE) in lopims pipeine [2013-10-22 Tue] - corrected spelling errors in phenoDisco doc [2013-10-29 Tue] Changes in version 1.3.0: - next devel version fot Bioc 2.14 PWMEnrich --------- Changes in version 3.5: - After further testing revert back to PWMEnrich 2.x group P-value algorithm - Introduced group sorting by top motifs Changes in version 3.1.4: - New way of estimating P-value for groups of sequences. Note this will produce different P-values for groups of sequences than PWMEnrich 2.x ! QDNAseq ------- Changes in version 1.0.0 (2014-04-14): INITIAL RELEASE - initial release as part of Bioconductor 2.14 qpgraph ------- Changes in version 1.20: USER VISIBLE CHANGES - Functions qpRndHMGM() and qpSampleFromHMGM() which were defunct in the previous release, are now removed from the package. - The execution of function qpGetCliques() can be now interrupted with CTRL+C and should allow to process GUI events. - Function qpBoundary() with argument logscale.bdsize=TRUE now handles plotting of boundaries of size 0 by setting them to 1 (=log(1)=0) for plotting purposes only. NEW FEATURES - Function qpCItest() when assuming a mixed GMM returns the fraction of variance explained (partial eta-squared) as estimate. See manual page for further details. BUG FIXES - Several bugfixes related to the simulation of mixed GMMs and eQTL networks. QuasR ----- Changes in version 1.4.0: NEW FEATURES - new arguments mapqMin and mapqMaxm in qCount, qProfile, qMeth and qExportWig allow to select alignments based on mapping quality - qAlign gains checkOnly argument which allows checking for existing alignments without triggering new alignments in case of missing ones r3Cseq ------ Changes in version 1.9.2 (2013-11-11): - fixed the bugs in function getFragmentsPerWindow for "overlapping window" Changes in version 1.9.1 (2013-10-21): - added the yLim input parameter of plotInteractionsNearViewpoint - added the log2 cutoff ratio for the function plotInteractionsNearViewpoint - fixed the shift of interaction in the viewpoint chromosome found in the function getFragmentsPerWindow - fixed the missing input parameter for the function getBatchReadCountPerWindow - fixed the class of r3CseqInBatch RamiGO ------ Changes in version 1.9.5: - RamiGO is now using AmiGO v2 Visualize as the default web server. Changes in version 1.9.1: - added citation information. Please cite http://bioinformatics.oxfordjournals.org/content/29/5/666.full Rariant ------- Changes in version 1.0.0: - First stable release with Bioconductor 2.14 (2014-04) rBiopaxParser ------------- Changes in version 2.1.7: - BUGFIX: fixed setkey for parsed biopax models - BUGFIX: fixed possible uses of complete URLs for ids (e.g. in PathwayCommons) - BUGFIX: fixed parameter checking failing due to data.table version 1.9.2. This will be fixed anyways when data.table 1.9.3. is out. Changes in version 2.1.5: - BUGFIX: Fixed several bugs relating to the default BioPAX version parameter biopaxlevel. - The package requires R >= 3.0 due to data.table requiring Reshape2, requiring plyr, requiring Rcpp. :-( Changes in version 2.1.3: - BUGFIX: Switched from rep_len to rep in order to continue R<3.0 support. Changes in version 2.1.1: - Attention: This is a major update and might introduce backwards incompatibility to previously parsed data! - Speed issues in previous versions were common with huge databases like Reactome or PathwayCommons, and with search & replace operations in the internal data.frame. - The data.table package is now required and imported for rBiopaxParser. - The internal data model has been switched from data.frame to data.table to speed up working with the rBiopaxParser. - The "df" slot of the biopax object, a data.frame object, is gone. Use the "dt" slot, a data.table, to directly access to biopax data. - If you work with the "df" slot of the biopax object in your current code, you have to make yourself comfortable with using the data.table syntax! - All functions which return a subset of the internal data, return a data.table object now. - A long standing bug of deeply nested XML instances has been fixed. See http://permalink.gmane.org/gmane.science.biology.informatics.conduct or/48534 - The default parameter specifying the Biopax Level (usually called biopaxlevel) has been changed and defaults to 3 now. - Functions selectInstances, getInstanceProperty, getReferencedIDs, splitComplex, getInstanceClass and many others now acceps either a biopax object or a compatible internal data.table. Changes in version 1.3.3: - fixed download links. Added links for the NCI databases with fixed XML encoding ( see discussion at http://sourceforge.net/mailarchive/message.php?msg_id=30106560) - added TemplateReactionRegulation to be plotted in pathway2RegulatoryGraph - future versions will likely switch to data.table support to deal with huge BioPAX databases from Reactome et al RDAVIDWebService ---------------- Changes in version 1.1.4: BUG FIXED - getFunctionalAnnotationChartFile bug was fixed. Now threshold and count parameter works as supposed (Thanks to Ulrik Stervbo) Changes in version 1.1.3: MINOR CHANGES - Added again into the repository. Changes in version 1.1.2: CODE CHANGES - In setAs(from="data.frame", to="DAVIDFunctionalAnnotationChart") function PValue field force to numeric data type (thanks to Marc Carlson) NEW FEATURES - Apache Axis time out parameter modification set/getTimeOut - Apache Axis http protocol version parameter modification set/getHttpProtocolVersion DOCUMENTATION - Vignette Trouble shooting section added with apache axis parameter examples. Changes in version 1.1.1: DOCUMENTATION - CITATION file was included. - Minor updates to DAVIDWebService-class and DAVIDWebService-package man pages and Roxygen2 quotes, in order to include the article citation. - Vignette email parameter invocation corrected. CODE CHANGES - DAVIDWebService initialize email parameter order modification (email, ..., url) DEPENDENCY CHANGES - Category, GO.db, RBGL and rJava packages were moved to import. - NAMESPACE file updated accordingly. Changes in version 1.1.0: MINOR CHANGES - Bump y in version x.y.z to odd number in 2.14 devel ReactomePA ---------- Changes in version 1.7.2: - bug fixed for multi-organisms support <2013-12-09, Mon> RedeR ----- Changes in version 1.12.0: - Improved interactive layout algorithm. - User interface is simplified, some shortcuts have been added. - Final release cycle of deprecated functions moved to the addGraph/getGraph related methods. - Deprecated plugin builder methods have been removed. RefNet ------ Changes in version 1.0.0: NEW FEATURES - Two sets of interactions, retrieved automatically from the AnnotationHub, in addition to the many provided by PSICQUIC: - gerstein-2012: "Architecture of the human regulatory network derived from ENCODE data", Gerstein et al, pmid 22955619 - hypoxiaSignaling-2006: "Hypoxia signalling in cancer and approaches to enforce tumour regression", Pouyssgur et al, pmid 16724055 - These interactions have been expressed in the standard RefNet 19-column format for easy querying. - a.canonical - b.canonical - relation - bidirectional - detectionMethod - pmid - a.organism - b.organism - a.common - a.canonicalIdType - b.common - b.canonicalIdType - cellType - a.modification - a.cellularComponent - b.modification - b.cellularComponent - provider - comment ReQON ----- Changes in version 1.9.1: - Minor changes were made to the vignette. September 4, 2012 Our manuscript describing ReQON has been published in BMC Bioinformatics. Refer to this paper for further description of the ReQON algorithm and a comparison with other quality score recalibration algorithms. Please cite this paper if you use our package. Cabanski CR et al. (2012) ReQON: a Bioconductor package for recalibrating quality scores from next-generation sequencing data. BMC Bioinformatics 13(221). doi:10.1186/1471-2105-13-221. Rgraphviz --------- Changes in version 2.7: - Fixed include statements in Graphviz code. rhdf5 ----- Changes in version 2.8.0: NEW FEATURES - New function h5version implemented. - New low level general library functions H5open, H5close, H5garbage_collect, H5get_libversion, and H5Dset_extent implemented. USER VISIBLE CHANGES - h5createDataset automatically uses chunking and compression. - Added a warning if chunk size is equal to dimensions for large compressed datasets. BUG FIXES - C-stack overflow when reading large fixed-length strings. - error in i/o with chunksize or blocksize parameters. - compiling errors due to missing int return value. roar ---- Changes in version 0.99.6: NEW FEATURES - No new features, just adopted the suggested format for the NEWS file BUG FIXES - No changes classified as 'bug fixes' rols ---- Changes in version 1.5.2: - pretty printing with strwrap(mtd[...]) in vignette and termMetadata S3 printing method for readable output (suggestion from Martin Morgan) [2014-02-18 Tue] - Using BiocStyle vignette [2014-02-18 Tue] Changes in version 1.5.1: - split go terms (PRO:...) instead of ids (PR:...) in vignette tgnqueryShow chunk <2013-10-19 Sat> Changes in version 1.5.0: - new devel for Bioc 2.14 rpx --- Changes in version 0.99.9: - In pxref, dealing with cases without any or pending publications [2014-04-01 Tue] Changes in version 0.99.8: - fix leftover issues from renaming package (d.tenenbaum) [2014-03-30 Sun] Changes in version 0.99.7: - renamed to rpx due to CRAN name clash [2014-03-28] Changes in version 0.99.6: - more typos in vignette [2014-03-12 Wed] Changes in version 0.99.5: - Suggestions, biocView and typos reported by Nate Hayden [2014-03-12 Wed] - added Runit test [2014-03-12 Wed] - use ae fonts in vignette [2014-03-12 Wed] Changes in version 0.99.4: - Update reference in man and vignette [2014-03-11 Tue] - Typos in vignette [2014-03-11 Tue] Changes in version 0.99.3: - reverting pxannounced to empty signature to fix warning [2014-03-05 Wed] Changes in version 0.99.2: - replacing download.file by getURL to download annoucement rss over https <2014-03-05 Wed> Changes in version 0.99.1: - fixing pxfiles ending by \r on Windows [2014-03-05 Wed] Changes in version 0.99.0: - added a vignette [2014-03-05 Wed] - handle invalid identifiers [2014-03-05 Wed] rqubic ------ Changes in version 1.8.1 (2011-08-02): - Fix errors in documentations Rsamtools --------- Changes in version 1.15.0: NEW FEATURES - asSam converts BAM files to SAM files - razip, bgzip re-compress directly from .gz files - yieldReduce through a BAM or other file, applying a MAP function to each chunk and reducing the result to it's final representation SIGNIFICANT USER-VISIBLE CHANGES - bgzip default extension changed to '.bgz' - seqinfo,BamFile-method attempts to return seqnames in 'natural' order, e.g., chr1, chr2, ... - yieldSize now works on BAM files queried with ranges. Successive ranges are input until the total number of records first equals or exceeds yieldSize.. - scanFa supports DNA, RNA, and AAStringSet return objects BUG FIXES - scanFa returns correct sequence at the very end of files - razip compresses small files - applyPileups no longer crashes in the absence of an index file Rsubread -------- Changes in version 1.14.0: NEW FEATURES - featureCounts automatically re-orders paired end reads if they were sorted by chromosomal locations in the input. It can also deal with read pairs in which only one end was included in the input. - featureCounts is more robust in processing different variants of GTF/GFF annotation files. - Subjunc can detect exon-exon junctions which are located at the start or end of reads. It can detect non-canonical junctions ('reportAllJunctions' option) in addition to canonical junctions, and it can also be used to detect chimerism in both RNA-seq and gDNA-seq data. - Both align (Subread aligner) and subjunc now take gzipped FASTQ files and outputs BAM files in their default settings. They accept multiple input files as well. - Breakpoint locations are reported along with mapping location of each fusion read in SAM/BAM files, using tags including CC(chromosome name), CP(mapping position), CG(CIGAR string) and CT(strand). - A full index (no gaps) can be built for a reference genome to further speed up read mapping. - qualityScores() and propmapped() functions were rewritten. - Bug fixes. rTANDEM ------- Changes in version 1.3.9: - Capitalisation aliases added for most functions. - The rtandem function now has an 'output.path' argument. BUG FIXES - Changed default parameters to prevent the risk of not generating output files. - Fixed a bug with 'rtandem()' where the function would not take a complex rTTAXO object as argument. Changes in version 1.3.8: BUG FIXES - Fixed a memory leak associated with PTMTreeSearch. - Removed an unwanted side-effect from the function GetPeptides(). Changes in version 1.3.7: NEW FEATURES - rTANDEM now includes the PTMTreeSearch scoring algorithm. - New function to set default values for PTMTreeSearch algorithm. Changes in version 1.3.5: NEW FEATURES - New rTResult_s class support saving spectra. - New function 'ms2.plot' to visualize spectra. Changes in version 1.3.4: NEW FEATURES - rTANDEM now supports TPP's hrk-score function. BUG FIXES - Fixed a bug with k-score function. Changes in version 1.3.3: NEW FEATURES - Functions have been implemented to create and manipulate parameter objects (S3 class rTParam). Those functions give default values for instrument-specific parameters for some types of mass spectrometer as well as default values for general parameters. Changes in version 1.3.2: NEW FEATURES - rTANDEM now supports the k-score function. It can be used by setting the parameter 'scoring, algorithm' to "k-score". RTN --- Changes in version 1.2.0: - Introduced variant set enrichment analysis for regulons. rTRM ---- Changes in version 1.2: - An arbitrary number of targets can be specified in findTRM(). This allows to use the same list of TFs for target and query, in order to identify TRMs using information from predicted TFBS only. - BioGRID dataset updated to release 3.2.11 (April 2014) - getBiogridData() retrieves by default the latest BioGRID release www.thebiogrid.org) SANTA ----- Changes in version 1.3.10 (2014-03-03): NOTES: - Fixed minor memory leak in the Knet function. sapFinder --------- Changes in version 0.99.4: BUG FIXES - *To fix a bug of "index.js" that may cause a confusing CSS layout of index html page. Changes in version 0.99.3: NEW FEATURES - *Add some BiocViews items to packages. *Reduce the size of testing data. *Make import and export much more continent. *To make package consistent with bioconductor in the coding style. *Use BiocStyle for vignette. BUG FIXES - *To fix a bug of vignette document that may cause the package checking to crash. Changes in version 0.99.2: BUG FIXES - *Resolve some errors and warnings. Changes in version 0.99.0: - *Package released. SCAN.UPC -------- Changes in version 2.5.8: NEW FEATURES - This package now provides "generic" functions for UPC normalizing any type of gene-expression data. These values can be input as vectors or ExpressionSet objects. This means that data from Illumina BeadChip microarrays or any other type of microarray can be UPC normalized with relative ease. It is also easy through integration with the GEOquery package to UPC normalize any preprocessed data set from GEO. - This package now uses the ComBat function from the sva package to make it easy to adjust gene expression data for batch effects. This can be done for any type of expression data. - RNA-Sequencing data can now be input as matrix files and/or where a header is present in the input data files. NOTES - The SCAN_TwoColor and UPC_TwoColor functions have changed. They now return ExpressionSet objects. - The SCAN_TwoColor and UPC_TwoColor methods now add an integer suffix to each probe for which there is a duplicate name. - The UPC_RNASeq function now also returns an ExpressionSet object. - A bug was fixed in which UPC_RNASeq returned NA values if there was no entry in the annotation file. SeqArray -------- Changes in version 1.3.2: - update test codes to avoid the conflict Changes in version 1.3.1: - update according to the new version of VariantAnnotation shinyTANDEM ----------- Changes in version 1.1.4: BUG FIXES - Better error handling, error messages and conditions for missing data. Changes in version 1.1.3: BUG FIXES - Corrected problems arising from incompatibility between data.table and data.frame subsetting syntaxes. Changes in version 1.1.2: NEW FEATURES - MS2 spectra can now be visualized. - The 'Result Statistics' and 'Peptides view' tab are now ready. BUG FIXES - Corrected a bug in the selection of proteins by number of peptides. ShortRead --------- Changes in version 1.21: NEW FEATURES - writeFastq can write (and does so by default) gz-compressed files SIGNIFICANT USER-VISIBLE CHANGES - Use BiocParallel rather than srapply, mark srapply as 'Deprecated' - qa,character-method defaults to type="fastq" - Input of 'legacy' formats marked as such - alphabetByCycle supports amino acid string sets snm --- Changes in version 1.11: - Now uses lme4 R (>= 1.0) - Default nbins=20 - New argument lmer.max.iter allows one to cap the number of lmer iterations SomaticSignatures ----------------- Changes in version 1.0.0: - First stable release with Bioconductor 2.14 (2014-04) supraHex -------- Changes in version 1.1.17: NEW FEATURES - Add new functions for advanced heatmap visualisation and tree-based analysis of sample relationships Changes in version 1.1.2: NEW FEATURES - Add a new function "sMapOverlay" to overlay additional data to the trained map synapter -------- Changes in version 1.5.7: - Enable setting number of missed cleavages (closes #53) [2014-03-24 Mon] Changes in version 1.5.6: - change the default value of grid.ppm.from to 2 (was 5 before) [2014-03-05 Wed] - change the separator in GridDetails' names to ":" (was "." before) [2014-03-07 Fri] - test for corresponding Pep3D file (closes #42) [2014-03-19 Wed] Changes in version 1.5.5: - fix a bug in the calculation of non unique matches in gridSearch2 (part of searchGrid); results in a higher number of non unique matches (some of the reported -2 will now be reported as 2 in the grid details) [2014-03-05 Wed] - partial rewrite of gridSearch2 (part of searchGrid) for faster grid calculation [2014-03-04 Tue] Changes in version 1.5.4: - biocViews update Changes in version 1.5.3: - modified findMSeEMRTs (part of searchGrid) for faster grid calculation [2014-02-28 Fri] - typos in manual [2014-02-25 Tue] - replace readFasta by Biostrings::readAAStringSet [2014-02-25 Tue] - replace digest by cleaver::cleave [2014-02-25 Tue] Changes in version 1.5.1: - typo in vignette [2014-02-18 Tue] Changes in version 1.5.0: - new devel version for Bioc 2.14 TargetSearch ------------ Changes in version 1.20.0: BUG FIXES - Write the actual retention index value instead of the work 'RI' in ProfileCleanUp. TCC --- Changes in version 1.3.2: - DESeq2 was implemented in TCC for identifying DEGs. - EBSeq was removed from TCC. - arguments of 'WAD' function were changed. - fixed bug in '.testByDeseq' that missing to treat size factors. - the strategies for DE analysis of paired two-group dataset were implemented. - add the section for describing DE analysis of paired two-group dataset into vignette. tigre ----- Changes in version 1.16.1: - More informative error messages TransView --------- Changes in version 1.7.4: BUG FIXES - Removed import error introduced with version 1.7.2 Changes in version 1.7.3: BUG FIXES - Minor bug fix Changes in version 1.7.2: NEW FEATURES - annotatePeaks now assigns a gene to the peak center instead of the peak limits - annotatePeaks takes the new argument 'reference' to enable alternative peak to gene body associations Changes in version 1.7.1: BUG FIXES - Minor correction to avoid warning messages issued after GRanges to data.frame conversion unifiedWMWqPCR -------------- Changes in version 0.9.9: SIGNIFICANT USER-VISIBLE CHANGES - First submission of uWMWqPCR to BioConductor. VariantAnnotation ----------------- Changes in version 1.10.0: NEW FEATURES - add support for ##contig in VCF header - add 'meta<-', 'info<-', 'geno<-' replacement methods for VCFHeader - add 'header<-' replacement method for VCF - add strand to output from locationVariants() - add support for writeVcf() to process Rle data in geno matrix - readVcf() now parses 'geno' fields with Number=G as ((#alleles + 1) * (#alleles + 2)) / 2 - writeVcf() now sorts the VCF when 'index=TRUE' - add 'fixed<-,VCFHeader,DataFrameList' method - add convenience functions for reading VCF into VRanges - add Rplinkseq test script - add 'isSNV', 'isInsertion', 'isDeletion', 'isIndel', 'isTransition', 'isPrecise', 'isSV' and 'isSubstitution' generics - add 'isSNV', 'isInsertion', 'isDeletion', 'isIndel' methods for VRanges and VCF classes - add match methods between ExpandedVCF and VRanges - add support for VRanges %in% TabixFile MODIFICATIONS - expand,VCF-method ignores 'AD' header of 'AD' geno is NULL - add support for SIFT.Hsapiens.dbSNP137 - remove locateVariants() dependence on chr7-sub.vcf.gz - modify expand() to handle 'AD' field where 'Number' is integer - rename readVRangesFromVCF() to readVcfAsVRanges() - remove check for circular chromosomes in locateVariants() and predictCoding() and refLocsToLocalLocs() - modify filterVcf() to handle ranges in ScanVcfParam - pass 'genetic.code' through predictCoding() - change default to 'row.names=TRUE' for readGT(), readGeno(), and readInfo() - fixed() on empty VCF now returns DataFrame with column names and data types vs an empty DataFrame - update biocViews - modify 'show,VCF' to represent empty values in XStringSet with '.' - replace rtracklayer:::pasteCollapse with unstrsplit() DEPRECATED and DEFUNCT - remove defunct dbSNPFilter(), regionfilter() and MatrixToSnpMatrix() - deprecate defunct readVcfLongForm() BUG FIXES - modify expand.geno() to handle case where header and geno don't match - modify writeVcf() to write out rownames with ":" character instead of treating as missing - fix how sample names were passed from 'ScanVcfParam' to scanVcf() - fix bug in 'show,VCF' method - fix bugs in VRanges -> VCF coercion methods - fix bug in lightweight read* functions that were ignoring samples in ScanVcfParam - fix bug in writeVcf() when no 'ALT' is present VariantFiltering ---------------- Changes in version 0.99: USER VISIBLE CHANGES - Submission of the first version to the Bioconductor project (start date: 26 September, 2013) VariantTools ------------ Changes in version 1.6.0: NEW FEATURES - Add pileupVariants function as an alternative to tallyVariants for computing nucleotide pileups using Rsamtools, instead of gmapR. In the future, this should allow VariantTools to become independent of gmapR, but the full variant statistics will only be available via tallyVariants. USER-VISIBLE CHANGES - See the NEWS for gmapR to learn about changes to tallyVariants output. wateRmelon ---------- 1.3.1: thanks to several users for bug reports! xcms ---- Changes in version 1.39.6: USER VISIBLE CHANGES - Massifquant reports the maximum intensity for each isotope trace (peak). This is useful for interactive parameter optimization. BUG FIXES - Major memory reduction in parallel fillPeaks() thanks to Jan Stanstrup. Now using an environment to mirror gvals to each list item in the very large argList. Changes in version 1.39.4: BUG FIXES - Fixed write.cdf(), which had an intensity offset of +1, added a unit test Changes in version 1.39.3: BUG FIXES - New R-devel check unload better. Lingering ramp code removed, import from mzR. Cleaned up other errors in package check. Changes in version 1.39.1: BUG FIXES - Updated doubleMatrix c code to allow for larger profile matrixes REQUIRED CHANGES - Moved inst/doc to vignettes yaqcaffy -------- Changes in version 1.23.1: - moved inst/doc to vignettes [2013-10-19 Sat] Packages removed from the release ================================= The following packages are no longer in the release: Agi4x44PreProcess, maDB, pgUtils
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http://www.phys.boun.edu.tr/faculty_wp/ersan_demiralp.html
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# Ersan Demiralp (Professor)
B.A. : METU - Physics (1987)
M.S. : Bilkent Univ. - Physics (1989)
Ph.D.: California Institute of Technology - Applied Physics (1996)
Areas of Interest
• Atomic and Molecular Physics
• Condensed Matter Physics
Ongoing Projects
• Bound State Solutions of the Schrodinger Equation with Dirac Delta Potentials
• Bose-Einstein Condensation
Selected Publications
• "Bound States of N-dimensional Harmonic Oscillator Decorated with Dirac Delta Functions", J. Phys A: Mathematical and General, 38, 4783-4793, (2005)
• "Structural and Electronic Properties of Novel Nanoscale $C_{4n}S_{4n}$ Molecules" ,J. of Molecular Structure(Theochem), 635,125-131,(2003)
• "The MS-Q Force Field for Ceramics; Application to the Quartz-Stishovite Phase Transition and to Silica Glass"Phys. Rev. Lett. 82 (8), 1708 (1999)
• "The Conduction Properties of An Organic Superconductor, $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$, Using the Hubbard Unrestricted Hartree-Fock Band Model", Phys Rev B 56. , (18), 11 907 (1997)
• "The Electron-Transfer Boat-Vibration Mechanism For Superconductivity In Organic Molecules Based on BEDT-TTF~(ET)", J of Amer. Chem. Soc., 117, 8154 (1995)
• "Prediction of New Donors for Organic Superconductors", Synthetic Metals, 72, 297 (1995)
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https://learnzillion.com/lesson_plans/8441-plot-points-on-a-coordinate-plane
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# Plot points on a coordinate plane
teaches Common Core State Standards 5.8C http://ritter.tea.state.tx.us/rules/tac/chapter111/index.html
teaches Common Core State Standards 5.AT.6 http://www.doe.in.gov/standards/mathematics
teaches Common Core State Standards CCSS.Math.Content.5.G.A.1 http://corestandards.org/Math/Content/5/G/A/1
teaches Common Core State Standards MAFS.5.G.1.1 http://www.cpalms.org/Public/search/Standard
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In this lesson you will learn how to plot points on a coordinate plane by moving on the X axis and then the Y axis.
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https://byjus.com/chemistry/shift-in-equilibrium-between-ferric-ions-and-thiocyanate-ions-experiment/
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# Study The Shift In Equilibrium Between Ferric Ions And Thiocyanate Ions By Increasing/Decreasing The Concentration Of Either Of The Ions
Let us study the equilibrium reaction between potassium thiocyanate and ferric chloride through the change in the concentration of color of the solution. The reaction and equilibrium constant is given by
The equilibrium constant is given by the formula
Finding equilibrium constant for the reaction between potassium thiocyanate and ferric chloride
At a constant temperature, the value of K also remains constant.
Increasing the concentration of either Fe3+ ion or thiocyanate ion would result in an increase in the concentration of [Fe(SCN)]2+ ions.
## Aim:
To understand the process of shift in equilibrium between ferric ions and thiocyanate ions by either increasing/decreasing the concentration of the ions
## Materials Required:
0.100g Ferric chloride, 0.100g Potassium thiocyanate, 2 Beakers of 100 mL capacity, 250 mL Beaker, 6 Boiling tubes, 4 Burettes, 2 Glass droppers, 1 Test tube stand, 1 Glass rod
## Procedure:
1. In a beaker dissolve 0.100g of ferric chloride salt in 100 mL of water and in another beaker dissolve 0.100 g potassium thiocyanate in 100 mL of water.
2. By mixing 20 mL of ferric chloride solution with 20 mL of potassium thiocyanate solution a bright blood red color solution will be obtained.
3. Fill this bright blood red color solution in a burette.
4. Take five boiling tubes measuring of equal size and then label them as a,b,c, d, and e.
5. Add 2.5 mL of blood red solution to each of the boiling tubes from the burette.
6. Add 17.5 mL of water to the boiling tube ‘a’ so that the total volume of solution in the boiling tube ‘a’ is 20 mL. (for your reference)
7. Now take three burettes and label them as A, B, and C.
8. Fill ferric chloride solution in burette A
9. FIll potassium thiocyanate solution in burette B
10. Fill burette C with water
11. Add 1.0 mL, 2.0 mL, 3.0 mL and 4.0 mL of ferric chloride solution to boiling tubes b, c, d, and e respectively from burette A.
12. From burette C add 16.5 mL, 15.5 mL, 14.5 mL, and 13.5 mL of water to boiling tubes b, c, d, and e respectively.
13. Compare the color intensity produced from the solution in each boiling tube with the color of the reference solution in the boiling tube ‘a’.
14. Take another set of four clean boiling tubes and fill them with 2.5 mL of blood red solution to each of the boiling tubes from the burette.
15. Repeat the experiment by adding 1.0 mL, 2.0 mL, 3.0 mL and 4.0 mL of potassium thiocyanate solution from burette B to the boiling tubes b′, c′, d′, and e′ respectively followed by addition of 16.5 mL, 15.5 mL, 14.5 mL and 13.5 mL of water.
16. Again compare the color intensity of the solution of these test tubes with reference equilibrium solution in the boiling tube ‘a’.
17. Record your results in the table given below
18. You may repeat the observations with different amounts of potassium thiocyanate and ferric chloride solution and compare with the reference solution.
## Precautions to be taken during the experiment:
• Use mildly diluted solutions of ferric chloride and potassium thiocyanate.
• Keep a watch on the color of the solutions in the boiling tube and reference test tube
• Use boiling tubes of the same size.
## Observation
Study of Equilibrium shift when the concentration of ferric ions is increased
Boiling Tube Amount of ferric chloride solution Change in color intensity as matched with the reference solution in tube “a” The direction of shift in equilibrium a Reference solution 2.5 mL blood red solution + 17.5 mL water Equilibrium position b 1.0 c 2.0 d 3.0 e 4.0
Study of Equilibrium shift when the concentration of thiocyanate ions are increased
Boiling Tube The volume of thiocyanate Change in color intensity as matched with the reference solution in tube “a” The direction of shift in equilibrium a Reference solution 2.5 mL blood red solution + 17.5 mL water Equilibrium position b 1.0 c 2.0 d 3.0 e 4.0
## Viva Voice:
1. Does the constancy in color intensity indicate the dynamic nature of equilibrium? Explain your answer with appropriate reasons.
No, since the color becomes constant even after the reaction stops at equilibrium.
2. What is equilibrium constant and how does it differ from the rate constant?
The equilibrium constant is given by
The equilibrium constant is independent of the initial concentration of reactants and is a function of temperature but remains constant at a constant temperature.
3. Why is it suggested to carry the experiment with dilute solutions?
Dilute solutions are safer on heating and do not cause damage in lab conditions.
4. Does temperature effect equilibrium?
Yes
5. Why boiling tubes of the same size are used in the experiment?
To get the exact measurement of the solution added for reference.
|
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https://socratic.org/questions/could-you-derive-the-rate-law-for-two-competing-first-order-reactions-and-the-fo
|
Chemistry
Topics
# Could you derive the rate law for two competing first order reactions and the formula for the product ratio, please?
Feb 10, 2016
The rate law is "rate" = -(k_1+ k_2)["A"]
#### Explanation:
The problem
$\text{A" stackrelcolor(blue)(k_1color(white)(m))(→) "B}$
$\text{A" stackrelcolor(blue)(k_2color(white)(m))(→) "C}$
Derive the overall rate law and the relative amounts of $\text{B}$ and $\text{C}$.
The differential rate law
(d["B"])/dt = k_1["A"]
(d["C"])/dt = k_2["A"]
-(d["A"])/dt = k_1["A"] + k_2["A"] = (k_1 + k_2)["A"]
Let ${k}_{3} = {k}_{1} + {k}_{2}$
Then
"rate" = -(d["A"])/dt = k_3["A"]
Integrated rate law for $\left[\text{A}\right]$
(d["A"])/dt = -k_3["A"]
(d["A"])/"[A]" = -k_3dt
int_("A₀")^"A" (d["A"])/"[A]" = -int_0^tk_3dt
$\ln {\left[\text{A"]_"A₀"^"A} = - {k}_{3} t\right]}_{0}^{t}$
$\ln {\left[\text{A"] – ln["A}\right]}_{0} = - {k}_{3} t$
$\ln {\text{[A]/"[A]}}_{0} = - {k}_{3} t$
"[A]"/["A"]_0 = e^(-k_3t)
$\left[{\text{A"] = ["A}}_{0}\right] {e}^{- {k}_{3} t}$
Integrated rate law for $\left[\text{B}\right]$
(d["B"])/dt = k_1["A"] = k_1["A"]_0e^(-k_3t)
int_0^"B" d["B"] = int_0^t k_1["A"]_0e^(-k_3t)dt
["B"] = k_1/k_3["A"]_0e^(-k_3t)]_0^t = -k_1/k_3["A"]_0(e^(-k_3t) –e^0) = -k_1/k_3["A"]_0(e^(-k_3t) –1)
${\left[\text{B"] = k_1/k_3["A}\right]}_{0} \left(1 - {e}^{- {k}_{3} t}\right)$
Integrated rate law for C
Similarly,
${\left[\text{C"] = k_2/k_3["A}\right]}_{0} \left(1 - {e}^{- {k}_{3} t}\right)$
Product ratio
${\left[\text{B"] = k_1/k_3["A}\right]}_{0} \left(1 - {e}^{- {k}_{3} t}\right)$
${\left[\text{C"] = k_2/k_3["A}\right]}_{0} \left(1 - {e}^{- {k}_{3} t}\right)$
"[B]"/"[C]" = (k_1/color(red)(cancel(color(black)(k_3)))color(red)(cancel(color(black)(["A"]_0(1 -e^(-k_3t))))))/ (k_2/color(red)(cancel(color(black)(k_3)))color(red)(cancel(color(black)(["A"]_0(1 -e^(-k_3t))))))
$\text{[B]"/"[C]} = {k}_{1} / {k}_{2}$
##### Impact of this question
377 views around the world
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https://ctftime.org/writeup/28135
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Tags: web
Rating:
I searched in google about the generation of windows 95 oem key Keys have the pattern **XXXXX-OEM-XXXXXXX-XXXXX**
The first part is 3 first digits are the day of the year and the 2 last are the year (95-03)
July 3rd was the 184th day of 1999 so the first part is 18499
The second part first digit is 0 and sum of the 6 more must be divisible by 7 I chose 0123456
Part 3 is just random numbers - unchecked
The key I used was 18499-OEM-0123456-11111 After going to http://ch1.sbug.se/?license=18499-OEM-0123456-11111 I got the flag
> SBCTF{CR4CK1NG_95_W4S_N0T_TH4T_H4RD}
**bonus** Win 95 had a lot of good keys and so there are to get the flag The exact number is 142880 * 10^5 = 14288000000 (from part 3 and 4)
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https://codegolf.stackexchange.com/questions/171884/overlapping-polyglots/173943
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# Overlapping Polyglots
Unlike many C&R challenges, this does not require a separate robbers post; the goal of the robbers is to crack the previous answer and then post a new one as a cop.
As answerers, you will write a series of polyglots that look like this (each column is a language, and each entry is the output of the answer in that language):
Language: 1 2 3 4 5 6 7 8 ...
...
(blank spaces mean that no behavior is required in that case).
Each answer should work in 3 languages and print 3 different consecutive numbers which are each one more than the numbers printed by the previous answer (the first answer prints 0, 1, and 2). Each answer uses two languages from the previous submission, and a third new language. The answerer should try to obfuscate what this third language is.
To post a new answer, you should:
• Crack the most recent answer by finding what its third language is.
• Preferably, add an explanation for your crack and notify the poster of the answer. Once your submission has been cracked, you should preferably add an explanation as well.
• Write a polyglot consisting of this answer's second and third languages, along with another language of your choice. Reveal your first two languages, but do not reveal your new one. It will be the next poster's goal to find this language (or any other language in which it works), so you should try to obfuscate it.
## Specifications
• The criteria for a valid programming language are the same as those of The Programming Language Quiz, Mark II - Cops:
• Each answer must run in less than a minute on a reasonable PC.
• You can reuse programming languages, but there must be at least two answers in between (so an individual answer cannot reuse a language).
• Cracking a submission consists of finding any programming language that prints the correct result, not just the intended one. If a submission is run in any language that was not declared or found to work, there are no requirements to do anything.
• You may not post twice (or more) in a row.
## Winning Criterion
The winning answer is whichever answer took to most time to be cracked. The challenge will never end, so it is always possible for the winning answer to change.
• Opened a chatroom for discussion about possible cracks and building polyglots. – Bubbler Sep 10 '18 at 23:35
• Can the answer output other things apart from the desired number? – NieDzejkob Sep 30 '18 at 9:21
• @NieDzejkob No, the program should only output the number, and yes, I'd prefer if the programs ran in under a minute. – Esolanging Fruit Oct 13 '18 at 10:59
• Here's a SEDE query that calculates the amount of time the answers stayed safe (in hours). – NieDzejkob Oct 15 '18 at 20:50
• @EmbodimentofIgnorance Yes, you can require command-line flags as they essentially define separate interpreters, and yes, the program must print only the number. The program may output to STDERR, but only the output to STDOUT is relevant. – Esolanging Fruit Feb 17 at 8:53
# Hexagony, Klein (101) and ???
xx={puts/}
gets87!@xx=p
main\
>9.*5,6v
This prints 7 in Hexagony, 8 in Klein (101), and 9 in ???.
The 9 does not work if a newline is added at the end of the code. Be careful if you're testing locally.
Edit: Being live for 20 hours is already a record, so I'll give some hints from now on. (Also because the language in question is IMO not yet well-known.)
### Hints
1. "The 9 does not work if a newline is added at the end" is very significant, as well as the first two spaces (which are ignored by both Hexagony and Klein).
2. The language is on TIO.
3. The first two spaces make the program jump to the last line. (It's not a 2D language.)
4. There's no explicit output command, and the v command ends the program.
### Explanation (cracked post)
In the source code
abcd={} -- a gaffe avoiding tactic in C++/C#
abcd[!1]= 1+2+3+4+5+6+7+8+9+10+11+12+13+17!
print(abcd[0>1+2+3 and 4+8+6<0-0]//35)
if 0>1 then a.next=';' en\
>1+6.@.@
The relevant instructions in Klein (101) are:
IP->.....................^...........IP->/
.........................|...................
.........................8
.........................\<-.............IP<-
@
Klein is fungelike 2D language where crossing the boundary of code area (which is a square) depends on the Klein topology. / and \ are mirrors.
The IP starts at upper left corner facing right. It meets a mirror towards the top boundary, and re-enters the code area on the right side as shown above. Then it hits the mirror again, 8 is pushed, and then (after passing through the boundary several times) stops at @. Then the content of the stack is printed to stdout, which is single 8.
# Befunge-96, Hexagony and ???
abcd={} -- a gaffe avoiding tactic in C++/C#
abcd[!1]= 1+2+3+4+5+6+7+8+9+10+11+12+13+17!
print(abcd[0>1+2+3 and 4+8+6<0-0]//35)
if 0>1 then a.next=';' en\
>1+6.@.@
This prints 6 in Befunge-96, 7 in hexagony and 8 in ???.
### Explanation
The hexagony code, when "prettified" is:
a b c d = { } -
- a g a f f e a v
o i d i n g t a c t
i c i n C + + a b c d
[ f a l s e ] = 1 + 2 +
3 + 4 + 5 + 6 + 7 + 8 + 9
+ 1 0 + 1 1 + 1 2 + 1 3 + 1
7 ! p r i n t ( a b c d [ 0 >
1 + 2 + 3 a n d 4 + 5 + 6 <
0 - 0 ] / / 3 5 ) i f 0 >
1 t h e n a . n e x t =
' ; ' e n d > 1 + 6 .
@ . . . . . . . . .
. . . . . . . . .
. . . . . . . .
The path of execution begins in the top left heading East. The top row doesn't do much. - changes the current memory edge so the value in it is 0. Execution continues heading east on the middle row where 7! loads 7 in the current memory edge and prints is as an integer. [ changes the instruction pointer to North East starting back at 7. After 7+3, execution then reaches [ which changes the instruction pointer to North West starting in the South East corner. Finally the path is ..@ where @ terminates the program.
# Lua, brainfuck, ???
abcd={} -- a gaffe avoiding tactic in C++
abcd[false]=1+2+3+4+5+6+7+8+9+10+11+12+13+14
print(abcd[0>1+2+3 and 4+5+6<0-0]//35)
if 0>1 then a.next=';' end
Prints 3 in Lua, 4 in brainfuck and 5 in ???.
Explanation for cracked post:
a=1+2+3+3+4+5+6+7+8+9
b=1+1+1
f=3--(-1)
c=7+9+13+11+12+3--1
g=a+b+c+1+2+3+4+5
j=9+7+g+c+b+a+g+g+g+g+g+g+1+2+3+4+1+1
h=1+1+1+1+333+1+1+1+111+1+1+1+333+1+1+1+1+1.
print(f)
• In Python 3, 3--(-1) is 2, so print(f) prints 2 (the other stuff is unnecessary)
• In Lua, -- again is a comment, so 3--(-1) is just 3, so print(f) prints 3 (other stuff is again unnecessary)
• In brainfuck, there are 57 plusses and 5 minuses setting the first cell on the tape to 52, and the . outputs character 52 which is 4.
• +1 and Cracked – Zacharý Sep 9 '18 at 11:50
# Trigger, JavaScript and ???
[ //aТ/\\ ][ //е"6
console.log(111-111+12)]
//!'!/-²6-²52
Prints 11 in Trigger, 12 in JavaScript, and 13 in REDACTED.
Since this has not been cracked for longer than any other answer so far, here are some hints:
• In case you didn't notice, the Т and е on the first line are multibyte characters.
• [ // and \\ ][ // are no-ops.
• The second line, as well as -²52, is dead code.
• The language does not have a concept of termination, so ²6 forms an infinite loop.
• To be specific, the second byte of the UTF-8 encoding of ², together with the 6, forms an infinite loop.
• The number being outputted is encoded by the /!'!/
• The language is not on Try It Online, Rosetta Code or Esolangs.
• The only available form of output is a 1bpp screen.
• The screen's aspect ratio is 2.
• While the language was not originally intended as machine code, FPGA implementations do exist.
• According to Wikipedia, the intended purpose of the language were video games.
• The only way to access the screen is a special instruction, that takes coordinates in selectable registers, and the height as an immediate, and XORs an 8 by n bitmap onto the screen. To make collision detection easier, as well as make it possible to clear the screen, one of the registers will be set when any pixel gets set back to off.
## Explanation
Well, this took some time to get cracked. Let's see how the code looks:
0200 5b20 SE VB, V2 ; Skip the next instruction if VB = V2. Since all
0202 2f2f CALL 0xF2F ; registers start at 0, this call will be skipped. This
; hides the bytecode from JavaScript.
0204 61d0 LD V1, 0xD0 ; A useless load. Necessary to use a UTF-8 continuation
0206 a22f LD I, 0x22F ; byte as an instruction and load the address of
; the sprite.
0208 5c5c SE VC, V5 ; A red herring supposed to suggest symmetry is
; important, as well as a totally intended eliminator
; of inaccurate implementations. Most documentation
; claims that the lowest nibble must be zero, but in
; the original COSMAC VIP implementation it's
; a don't-care.
This means that, while many available emulators behave correctly, the by-the-rules implementation is linked to in the second sentence of the Wikipedia page. Of course, it can't be run directly on an average PC, but I've found the Emma 02 emulator linked to on the COSMAC VIP page to work the best.
020A 205d CALL 0x05D ; Skipped.
020C 5b20 SE VB, V2 ; Same as with the very beginning. Red herring.
020E 2f2f CALL 0xF2F
0210 d0b5 DRW V0, VB, 5 ; Draw the sprite pointed to by I. Since V0 and VB
; haven't been written to yet, the sprite will be drawn
; in the top-left corner of the screen. The height is
; an immediate.
0212 2236 CALL 0x236 ; Jump over the JavaScript and Trigger code. It doesn't
; matter that we never return.
0214-022E *never used*
022F 2f DB %00101111 ; Sprite data.
0230 21 DB %00100001
0231 27 DB %00100111
0232 21 DB %00100001
0233 2f DB %00101111
0234-0235 *never used*
0236 b236 JP V0, 0x236 ; Since V0 is still zero, this is an infinite loop.
0238-023C *never used* ; Together with the previous two lines, it's the
; -²6-²52. It's a red herring supposed to suggest
; prefix, or Polish, notation.
• Don't tell me this is machine code on some processor. – SIGSTACKFAULT Sep 21 '18 at 12:35
• @Blacksilver I've been assuming so since two hints ago - what else would look like this, not be on Esolang, but still be notable enough for Wikipedia? – Ørjan Johansen Sep 21 '18 at 18:31
• @Blacksilver OK. – NieDzejkob Sep 22 '18 at 8:51
• @ngm sorry, but no – NieDzejkob Sep 23 '18 at 9:23
• cracked, I believe, according to the rules. – ngm Sep 26 '18 at 18:26
# Python 2, Python 3, ???
a={1,2}
print(1+#a
--bool(1/2)
)
This prints 1 in Python 2, 2 in Python 3, and 3 in ???.
Crack explanation (Cracked post):
#define print(A) main(){puts("0");}
print(1+bool(1/2))
• 0: C: The first line defines a function-like macro print that ignores its single argument and evaluates to main(){puts("0");}, a full program that prints 0 and exits. The whole expression 1+bool(1/2) is ignored when the print( ) macro on the second line is expanded to main(){puts("0");}.
• 1: Python 2: The first line is a comment. 1/2 uses integer division in Python 2, giving 0. This value is then interpreted as a boolean (bool(0) -> False) and then added to 1 (1+False -> 1), and then printed.
• 2: Python 3: The first line is a comment. 1/2 uses float division in Python 3, giving 0.5. This value is then interpreted as a boolean (bool(0.5) -> True) and then added to 1 (1+True -> 2), and then printed.
# JavaScript, CHIP-8, and ???
[ //aТ/\\ ][ //е"6
console.log(111-111+12)]
//!'!/-²6-²52@++++2345
12 in JavaScript, 13 in CHIP-8, and 14 in ???
I'm going to go out on a limb and call this one cracked, although I can't quite get it to work I'm sure of the language (which seems to be what the rules ask for.)
Here is an imperfect explanation of the cracked post
The code in hexadecimal "is" (I might be slightly off):
[ 0x5b, 0x20, 0x2f, 0x2f, 0x61, 0xD0, 0xA2, 0x2f, 0x5c,
0x5c, 0x20, 0x5d, 0x5b, 0x20, 0x2f, 0x2f, 0xD0, 0xB5,
0x22, 0x36, 0x0a, 0x63, 0x6f, 0x6e, 0x73, 0x6f,
0x6c, 0x65, 0x2e, 0x6c, 0x6f, 0x67, 0x28, 0x31,
0x31, 0x31, 0x2d, 0x31, 0x31, 0x31, 0x2b, 0x31,
0x32, 0x29, 0x5d, 0x0a, 0x2f, 0x2f, 0x21, 0x27,
0x21, 0x2f, 0x2d, 0xb2, 0x36, 0x2d, 0xb2, 0x35, 0x32 ]
You can go here, click "Binary Tools" and paste this into the byte array box. Click "Decompile".
The key elements of the code are: instructions to say where the "number" is, the sprite command that prints the number, the correct amount of junk here and there, and the following:
: label-0
0x2F
0x21
0x27
0x21
0x2F
To see what this represents you can click "Sprite Editor" and paste these hexadecimals into the box underneath. You'll see the answer:
I'm pretty sure you can then put anything you like at the end and the CHIP-8 result will not change, hence the new entry.
I would be delighted if someone could get this fully working, rather than the "proof" of the answer I've given here.
• I'm gonna allow that. I'll edit in an explanation later today. Good job. – NieDzejkob Sep 27 '18 at 9:29
• Cracked – Jo King Sep 29 '18 at 11:50
• Also, your hexadecimal must be wrong since it does not decode as valid UTF-8... – NieDzejkob Sep 29 '18 at 19:56
# C, Python 2, ???
#define print(A) main(){puts("0");}
print(1+bool(1/2))
This prints 0 in C, 1 in Python 2, and 2 in ???.
This will be extremely easy to crack for people who know Python, but I wanted a starting-off point for other answers. Subsequent answers should try to obfuscate the third language (I did not do this).
# Python 3, Lua, ???
a=1+2+3+3+4+5+6+7+8+9
b=1+1+1
f=3--(-1)
c=7+9+13+11+12+3--1
g=a+b+c+1+2+3+4+5
j=9+7+g+c+b+a+g+g+g+g+g+g+1+2+3+4+1+1
h=1+1+1+1+333+1+1+1+111+1+1+1+333+1+1+1+1+1.
print(f)
Prints 2 in Python 3, 3 in Lua and 4 in ???.
Explanation for cracked post:
a={1,2}
print(1+#a
--bool(1/2)
)
• In Lua, -- is a comment. In Python 2 and 3, -- indicates double negative in arithmetic.
• In Python 2 and 3, # is a comment. In Lua, # is the length operator.
• In Python 2, 1/2 is floor division, so it evaluates to zero. In Python 3 this is not the case. Because both versions of Python evaluate 0 to False, bool(1/2) evaluates to False in Python 2 and True in Python 3. When used in arithmetic, False is cast to 0 and True is cast to 1.
# ><>, Befunge-96 and ???
abcd={} -- a gaffe avoiding tactic in C++
abcd[false]=1+2+3+4+5+6+7+8+9+10+11+12+13+17!
print(abcd[0>1+2+3 and 4+5+6<0-0]//35)
if 0>1 then a.next=';' end
>1+6.@
This prints 5 in ><>, 6 in Befunge-96 and 7 in ???.
I know the intended solution was Befunge-93, but I couldn't resist.
### Explanation:
Befunge-96 follows the same path as ><>, but ignores unknown instructions, ending up adding one to the 5 and multiplying it by 9 to get 54, the ascii code for 6.
• cracked – jslip Sep 9 '18 at 13:10
# Commentator, Beatnik, ???
// k... nak... naKaka pagpAbaGaBag
fn llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch(s: &String){
}
fn pneumonoultramicroscopicsilicovolcanoconiosis(){
}
fn main(){
let s = String::from("17");
let t = "Hi! I am a cat. AOOOWRRRWWW! Me need Whiskas! Noow! Mee hungry hast bekommen. Feedme! sudo !!. Sad... six cable hostage wire cable diediediediee # */";
llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch(&s);
pneumonoultramicroscopicsilicovolcanoconiosis();
}
Outputs 15 in Commentator, 16 in Beatnik, and 17 in the hopefully one language you are supposed to find.
Okay, it's clue time:
• The name of the language refers to a compound of two elements, both of which make up your body, but with wildly varying percentages (which way depending on whether you're a robot).
• The language itself is on TIO, but the implementation isn't.
• Oh come on.
• Looks like Rust( fn main(), among other things), but it doesn't actually run in Rust (explicit lifetime required in the type of 's'), neither on TIO nor another interpreter I found. And I can't find any other language that uses fn as a function identifier. – Draco18s Oct 14 '18 at 18:34
• Huh, even the hint looks like Rust, which is a compound of Fe and O. I can't think of anything else. Maybe different compiler versions? – Bubbler Oct 18 '18 at 23:35
• I suspect this might be Rust compiled with mrustc, which is basically Rust without the borrow checker. – Esolanging Fruit Oct 20 '18 at 5:23
• @EsolangingFruit try it – NieDzejkob Oct 29 '18 at 20:57
• Three months later, I finally got around to cracking this – Esolanging Fruit Feb 2 at 8:54
# Brainfuck, ><>, and ???
abcd={} -- a gaffe avoiding tactic in C++
abcd[false]=1+2+3+4+5+6+7+8+9+10+11+12+13+14
print(abcd[0>1+2+3 and 4+5+6<0-0]//35)
if 0>1 then a.next=';' end
>1+9*,@
Prints 4 in Brainfuck, 5 in ><>, and 6 in ???
• In brainfuck, nothing changes.
• In ><>, v redirects the flow of the program downwards. The n is numeric output. ; ends execution.
• Cracked – Jo King Sep 9 '18 at 12:23
# Klein (101), Z80Golf, ???
!!8@e6v+4>9 \
Almost everything you can find on the internet is true
~Albert Einstein
~HUMAN IMAGE MACROS
# Beatnik, Rust, ???
fn avreg(){}
fn/*azxzzz avreg k zqyzzz ax quke
>>P0 ++puts++puts[pov]
\@�{>*}++puts++puts++puts++puts++puts++puts++puts++puts%
*/main(){print!("17")}
This prints 16 in Beatnik, 17 in Rust, and 18 in ???.
The � character on line 4 should be replaced with ASCII character 18 (this was not done in the TIO links since it's not relevant to either of them).
## Explanation (cracked):
The previous answer's language was Rust: specifically, Rust compiled with mrustc. mrustc is an experimental compiler, and as it is mostly intended for bootstrapping a valid version of rustc, it ignores borrow checking and mutability checking, allowing @NieDzejkob's snippet to compile without errors.
This program will work with the normal Rust compiler, so you don't need to install mrustc to test it.
## Hints
Since this answer has now gone the longest without being cracked, I'll leave a hint, and continue to do so regularly until it is cracked:
• It is a 2D language.
• While throwing languages at this at random (having not found much searching for "ascii codepoint 0x12 esolang"), I noticed that it actually outputs 15 in ><>, so that's neat – Unrelated String Mar 21 at 2:05
• It would appear that this doesn't print 18 in any language on TIO (without any header, footer, or command-line flags added at least). I do hope I didn't miss any, because it seems like it will probably be quite a bit harder to check through everything on esolangs, Wikipedia, and Rosetta Code... My best guess is that this is some sort of 2D language where either @, P, {, or m starts a character literal and something afterwards prints its codepoint in decimal, but that doesn't explain all of the ++s... – Unrelated String Apr 2 at 22:37
• @UnrelatedString Yes, I will confirm that it isn't a language on TIO. – Esolanging Fruit Apr 3 at 3:48
• Well, I might have wasted a day going through 100 languages on esolang.org trying to find one that fits... Then I read the ASCII 18 character thing and realized my approach was completely wrong as I searched for a totally different class of languages... – IQuick 143 Apr 19 at 17:23
• @IQuick143 herrings are red – Esolanging Fruit Apr 20 at 21:14
# Z80Golf, Somme, ???
!!8@e6v+4>9 \
1((111+111)/111)
00
~tz
This prints 9 in Z80Golf, 10 in Somme and 11 in ???.
Credit to Bubbler for cracking the previous post as Somme, which takes the column sum as the instructions. The first three columns evaluate to
A.;
Which pushes 10, prints it and exits.
# Somme, Trigger and ???
[,,E,D,,$,H,_,K,,$,,_,F,L]=!
[]+[]+!![]+[][111]
_=[111][F+L+E+E];[,J,,A,I,,B,C,S]=
[]+_;$=A+B+C+D+I+H+J+A+I+B+H R=_[$](H+K+I+J+H+C+S+H+B+B+I)();G=($[$]+[])[14]
R[A+B+C+D+B+E+K][E+B+G](12);
iP<
This prints 10 in Somme, 11 in Trigger, and 12 in ???.
Since the last two languages are easy to polyglot, I decided to mix that language in.
### Explanation (cracked post)
Trigger sees the whole code as a series of tokens (tokenization is greedy):
• Single byte (denote A)
• Two same bytes followed by a different byte (denote AAB)
• Three same bytes (denoted AAA)
• Four same bytes (denoted AAAA)
In the source code
!!8@e6v+4>9 \
1((111+111)/111)
00
~tz
the significant tokens are ((1 11+ 111 111, where the first two does nothing and the last two prints 1 each - thus 11.
# CHIP-8, Klein (100), ???
[ //aТ/\\ ][ //е"6
console.log(111-111+12)]
//!'!/-²6-²52@++++2345
%/ <#> 13
say 14
+ not not 15
Outputs 13 in CHIP-8 (I assume), 14 in Klein, and 15 in ???.
Another Klein topology, tsk tsk. I've preserved the code before the @, since I don't know what will affect CHIP-8.
### Clues
I'm kinda overdue for these, sorry. I'll try and add one a day.
• Removing the first half (first three lines) of the program still works.
• This is not a 2D language
• The language is on TIO
• The nots and the say can be removed without affecting the program
For reference, the program without that stuff looks like this:
%/ <#> 13
14
+ 15
Try it online!
• ...I'm scared. This runs in Runic and outputs 16. – Draco18s Sep 29 '18 at 17:48
• @Draco18s Intentional – Jo King Sep 30 '18 at 0:29
• It won't after my next update, as I added some better string handling to several operators (currently TIO pops a 1 and a string that is the made up from first line and goes "this isn't a value" and discards them, the update will concat, even though I have an operator for that, but concat operates on characters and numbers as well as strings, where as + treats them as numbers). But it was super spooky to be like "I wonder what...oh god, this could be left unmodified and be the next entry...if only I knew the ??? language..." – Draco18s Sep 30 '18 at 1:43
• Are you defining half by bytes, characters, lines, or something specific? – NieDzejkob Oct 8 '18 at 16:42
• – Bubbler Oct 12 '18 at 1:18
# Klein (100), Commentator, ???
/@++++2345
start:
program:
db 'function',10
jp null+\$8
sbc rbp,rbp
jnz program
jr program
halt
ex:
Outputs 14 in Klein (100), 15 in Commentator, 16 in ???.
I'm seriously bad at obfuscating polyglots.
### Explanation (Cracked post)
%/ <#> 13
14
+ 15
In Commentator, common comment tokens and spaces are the important commands, and any other characters are ignored.
• Space increments the current memory cell.
• <# does XOR 1 on the current memory cell.
• % is used to reset the current memory cell to zero.
Wait, there are 16 spaces after %, what happened?
It's actually a small bug (or feature?) in the interpreter. / is treated as the start of a 2-char command, so the space after it is consumed. But /<space> is undefined command (thus a no-op), so the space is effectively skipped.
|
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|
http://www.ck12.org/physics/Quantum-Mechanical-Model-of-the-Atom/lecture/The-Wave-Mechanical-Model/
|
<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Quantum Mechanical Model of the Atom
More exact than the Bohr Model, this model represents atomic energy levels with complex shapes.
%
Progress
Progress
%
The Wave Mechanical Model
The Wave Mechanical Model
A video describing the wave mechanical model of the atom.
|
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|
https://www.physicsforums.com/threads/mixing-problem.84979/
|
# Mixing problem
1. Aug 12, 2005
### asdf1
there's an example problem in my textbook, but i'm stuck on how to make the first move~
"a tank contains 1000gal of water in which 200lb of salt are dissolved. Fifty gallonw of brine, each containing (1+cost)lb of dissolbed salt, run into the tank per minute. The mixture, kept uniform by stirring, runs out the same rate. Find the amount of salt y(t) in the tank at any time t."
2. Aug 12, 2005
### Tide
HINT: $$\frac{dA}{dt} = r_{in} - r_{out}$$
where A is the amount of salt in the tank and r is the rate of salt flow in or out of the tank.
3. Aug 12, 2005
### mathmike
rate in = 50 lbs/min * (1+cost)lb / gal
rate in = y(t) / 1000 gal
dv /dt = rin - rout
find the intergating factor and ....
4. Aug 13, 2005
### asdf1
Why's rate out = y(t)/1000 gal?
5. Aug 13, 2005
### HallsofIvy
Staff Emeritus
It's not- there's a slight error. If y(t) is the amount of salt in the entire tank then y(t)/1000 is the amount of salt in each gallon. (Notice that that is now in "pounds per gallon". Since the solution is going out of the tank at 50 gallons per minute, there will be (y(t)/1000 pounds/gallon)(50 gallon/minute)= y(t)/20 pounds/min
Since mathmike got the inflow right, I suspect that was just a typo.
6. Aug 14, 2005
### asdf1
crummy.... I just noticed I have a lot of typos in my original question! sorry about that! :P
thanks! i didn't consider the different units... :P
|
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|
https://gsas-ii.readthedocs.io/en/latest/GSASIIutil.html
|
# 4. GSAS-II Utility Modules¶
## 4.1. GSASIIpath: locations & updates¶
Routines for dealing with file locations, etc.
Determines the location of the compiled (.pyd or .so) libraries.
Interfaces with subversion (svn): Determine the subversion release number by determining the highest version number where SetVersionNumber() is called (best done in every GSASII file). Other routines will update GSASII from the subversion server if svn can be found.
Accesses configuration options, as defined in config.py
GSASIIpath.DoNothing()[source]
A routine that does nothing. This is called in place of IPyBreak and pdbBreak except when the debug option is set True in config.py
GSASIIpath.DownloadG2Binaries(g2home, verbose=True)[source]
Download GSAS-II binaries from appropriate section of the GSAS-II svn repository based on the platform, numpy and Python version
GSASIIpath.GetBinaryPrefix(pyver=None)[source]
Creates the first part of the binary directory name such as linux_64_p3.9 (where the full name will be linux_64_p3.9_n1.21).
Note that any change made here is also needed in GetBinaryDir in fsource/SConstruct
GSASIIpath.GetConfigValue(key, default=None)[source]
Return the configuration file value for key or a default value if not present
Parameters: key (str) – a value to be found in the configuration (config.py) file default – a value to be supplied if none is in the config file or the config file is not found. Defaults to None the value found or the default.
GSASIIpath.GetVersionNumber()[source]
Return the maximum version number seen in SetVersionNumber()
GSASIIpath.IPyBreak()
A routine that does nothing. This is called in place of IPyBreak and pdbBreak except when the debug option is set True in config.py
GSASIIpath.IPyBreak_base(userMsg=None)[source]
A routine that invokes an IPython session at the calling location This routine is only used when debug=True is set in config.py
GSASIIpath.InvokeDebugOpts()[source]
Called in GSASII.py to set up debug options
GSASIIpath.LoadConfigFile(filename)[source]
Read a GSAS-II configuration file. Comments (starting with “%”) are removed, as are empty lines
Parameters: filename (str) – base file name (such as ‘file.dat’). Files with this name are located from the path and the contents of each are concatenated. a list containing each non-empty (after removal of comments) line found in every matching config file.
GSASIIpath.MacRunScript(script)[source]
Start a bash script in a new terminal window. Used on Mac OS X only.
Parameters: script (str) – file name for a bash script
GSASIIpath.MacStartGSASII(g2script, project='')[source]
Start a new instance of GSAS-II by opening a new terminal window and starting a new GSAS-II process. Used on Mac OS X only.
Parameters: g2script (str) – file name for the GSASII.py script project (str) – GSAS-II project (.gpx) file to be opened, default is blank which opens a new project
GSASIIpath.MakeByte2str(arg)[source]
Convert output from subprocess pipes (bytes) to str (unicode) in Python 3. In Python 2: Leaves output alone (already str). Leaves stuff of other types alone (including unicode in Py2) Works recursively for string-like stuff in nested loops and tuples.
typical use:
out = MakeByte2str(out)
or:
out,err = MakeByte2str(s.communicate())
GSASIIpath.SetBinaryPath(printInfo=False, loadBinary=True)[source]
Add location of GSAS-II shared libraries (binaries: .so or .pyd files) to path
This routine must be executed after GSASIIpath is imported and before any other GSAS-II imports are done.
GSASIIpath.SetConfigValue(parmdict)[source]
Set configuration variables from a dictionary where elements are lists First item in list is the default value and second is the value to use.
GSASIIpath.SetVersionNumber(RevString)[source]
Set the subversion version number
Parameters: RevString (str) – something like “$Revision: 5438$” that is set by subversion when the file is retrieved from subversion.
Place GSASIIpath.SetVersionNumber("$Revision: 5438$") in every python file.
GSASIIpath.TestSPG(fpth)[source]
Test if pyspg.[so,.pyd] can be run from a location in the path
GSASIIpath.addCondaPkg()[source]
Install the conda API into the current conda environment using the command line, so that the API can be used in the current Python interpreter
Attempts to do this without a shell failed on the Mac because it seems that the environment was inherited; seems to work w/o shell on Windows.
GSASIIpath.addPrevGPX(fil, configDict)[source]
Add a GPX file to the list of previous files. Move previous names to start of list. Keep most recent five files
GSASIIpath.commonPath(dir1, dir2)[source]
Check if two directories share a path. Note that paths are considered the same if either directory is a subdirectory of the other, but not if they are in different subdirectories /a/b/c shares a path with /a/b/c/d but /a/b/c/d and /a/b/c/e do not.
Returns: True if the paths are common
GSASIIpath.condaEnvCreate(envname, packageList, force=False)[source]
Create a Python interpreter in a new conda environment. Use this when there is a potential conflict between packages and it would be better to keep the packages separate (which is one of the reasons conda supports environments). Note that conda should be run from the case environment; this attempts to deal with issues if it is not.
Parameters: envname (str) – the name of the environment to be created. If the environment exists, it will be overwritten only if force is True. packageList (list) – a list of conda install create command options, such as: ['python=3.7', 'conda', 'gsl', 'diffpy.pdffit2', '-c', 'conda-forge', '-c', 'diffpy'] force (bool) – if False (default) an error will be generated if an environment exists (status,msg) where status is True if an error occurs and msg is a string with error information if status is True or the location of the newly-created Python interpreter.
GSASIIpath.condaInstall(packageList)[source]
Installs one or more packages using the anaconda conda package manager. Can be used to install multiple packages and optionally use channels.
Parameters: packageList (list) – a list of strings with name(s) of packages and optionally conda options. Examples: packageList=['gsl'] packageList=['-c','conda-forge','wxpython'] packageList=['numpy','scipy','matplotlib'] None if the the command ran normally, or an error message if it did not.
GSASIIpath.condaTest(requireAPI=False)[source]
Returns True if it appears that Python is being run under Anaconda Python with conda present. Tests for conda environment vars and that the conda package is installed in the current environment.
Returns: True, if running under Conda
GSASIIpath.exceptHook(*args)[source]
A routine to be called when an exception occurs. It prints the traceback with fancy formatting and then calls an IPython shell with the environment of the exception location.
This routine is only used when debug=True is set in config.py
GSASIIpath.findConda()[source]
Determines if GSAS-II has been installed as g2conda or gsas2full with conda located relative to this file. We could also look for conda relative to the python (sys.executable) image, but I don’t want to muck around with python that someone else installed.
GSASIIpath.fullsplit(fil, prev=None)[source]
recursive routine to split all levels of directory names
GSASIIpath.g2home = 'https://subversion.xray.aps.anl.gov/pyGSAS'
Define the location of the GSAS-II subversion repository
GSASIIpath.getsvnProxy()[source]
Loads a proxy for subversion from the proxyinfo.txt file created by bootstrap.py or File => Edit Proxy…; If not found, then the standard http_proxy and https_proxy environment variables are scanned (see https://docs.python.org/3/library/urllib.request.html#urllib.request.getproxies) with case ignored and that is used.
GSASIIpath.pdbBreak()
A routine that does nothing. This is called in place of IPyBreak and pdbBreak except when the debug option is set True in config.py
GSASIIpath.pipInstall(packageList)[source]
Installs one or more packages using the pip package installer. Use of this should be avoided if conda can be used (see condaTest() to test for conda). Can be used to install multiple packages together. One can use pip options, but this is probably not needed.
Parameters: packageList (list) – a list of strings with name(s) of packages Examples: packageList=['gsl'] packageList=['wxpython','matplotlib','scipy'] packageList=[r'\Mac\Home\Scratch\wheels\pygsl-2.3.3-py3-none-any.whl'] packageList=['z:/Scratch/wheels/pygsl-2.3.3-py3-none-any.whl'] None if the the command ran normally, or an error message if it did not.
GSASIIpath.proxycmds = []
Used to hold proxy information for subversion, set if needed in whichsvn
GSASIIpath.runScript(cmds=[], wait=False, G2frame=None)[source]
run a shell script of commands in an external process
Parameters: cmds (list) – a list of str’s, each ietm containing a shell (cmd.exe or bash) command wait (bool) – if True indicates the commands should be run and then the script should return. If False, then the currently running Python will exit. Default is False G2frame (wx.Frame) – provides the location of the current .gpx file to be used to restart GSAS-II after running the commands, if wait is False. Default is None which prevents restarting GSAS-II regardless of the value of wait.
GSASIIpath.setsvnProxy(host, port, etc=[])[source]
Sets the svn commands needed to use a proxy
GSASIIpath.svnChecksumPatch(svn, fpath, verstr)[source]
This performs a fix when svn cannot finish an update because of a Checksum mismatch error. This seems to be happening on OS X for unclear reasons.
GSASIIpath.svnCleanup(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest', verbose=True)[source]
This runs svn cleanup on a selected local directory.
Parameters: fpath (str) – path to repository dictionary, defaults to directory where the current file is located
GSASIIpath.svnFindLocalChanges(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest')[source]
Returns a list of files that were changed locally. If no files are changed,
the list has length 0
Parameters: fpath – path to repository dictionary, defaults to directory where the current file is located None if there is a subversion error (likely because the path is not a repository or svn is not found)
GSASIIpath.svnGetFileStatus(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest', version=None)[source]
Compare file status to repository (svn status -u)
Returns: updatecount,modcount,locked where updatecount is the number of files waiting to be updated from repository modcount is the number of files that have been modified locally locked is the number of files tagged as locked
GSASIIpath.svnGetLog(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest', version=None)[source]
Get the revision log information for a specific version of the specified package
Parameters: fpath (str) – path to repository dictionary, defaults to directory where the current file is located. version (int) – the version number to be looked up or None (default) for the latest version. a dictionary with keys (one hopes) ‘author’, ‘date’, ‘msg’, and ‘revision’
GSASIIpath.svnGetRev(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest', local=True)[source]
Obtain the version number for the either the last update of the local version or contacts the subversion server to get the latest update version (# of Head).
Parameters: fpath (str) – path to repository dictionary, defaults to directory where the current file is located local (bool) – determines the type of version number, where True (default): returns the latest installed update False: returns the version number of Head on the server the version number as an str or None if there is a subversion error (likely because the path is not a repository or svn is not found). The error message is placed in global variable svnLastError
GSASIIpath.svnInstallDir(URL, loadpath)[source]
Load a subversion tree into a specified directory
Parameters: URL (str) – the repository URL loadpath (str) – path to locate files
GSASIIpath.svnList(URL, verbose=True)[source]
Get a list of subdirectories from and svn repository
GSASIIpath.svnLocCache = None
Cached location of svn to avoid multiple searches for it
GSASIIpath.svnSwitch2branch(branch=None, loc=None, svnHome=None)[source]
Switch to a subversion branch if specified. Switches to trunk otherwise.
GSASIIpath.svnSwitchDir(rpath, filename, baseURL, loadpath=None, verbose=True)[source]
This performs a switch command to move files between subversion trees. Note that if the files were previously downloaded, the switch command will update the files to the newest version.
Parameters: rpath (str) – path to locate files, relative to the GSAS-II installation path (defaults to path2GSAS2) URL (str) – the repository URL loadpath (str) – the prefix for the path, if specified. Defaults to path2GSAS2 verbose (bool) – if True (default) diagnostics are printed
GSASIIpath.svnUpdateDir(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest', version=None, verbose=True)[source]
This performs an update of the files in a local directory from a server.
Parameters: fpath (str) – path to repository dictionary, defaults to directory where the current file is located version – the number of the version to be loaded. Used only cast as a string, but should be an integer or something that corresponds to a string representation of an integer value when cast. A value of None (default) causes the latest version on the server to be used.
GSASIIpath.svnUpdateProcess(version=None, projectfile=None, branch=None)[source]
perform an update of GSAS-II in a separate python process
GSASIIpath.svnUpgrade(fpath='/home/docs/checkouts/readthedocs.org/user_builds/gsas-ii/checkouts/latest')[source]
This reformats subversion files, which may be needed if an upgrade of subversion is done.
Parameters: fpath (str) – path to repository dictionary, defaults to directory where the current file is located
GSASIIpath.svnVersion(svn=None)[source]
Get the version number of the current subversion executable
Returns: a string with a version number such as “1.6.6” or None if subversion is not found.
GSASIIpath.svnVersionNumber(svn=None)[source]
Get the version number of the current subversion executable
Returns: a fractional version number such as 1.6 or None if subversion is not found.
GSASIIpath.whichsvn()[source]
Returns a path to the subversion exe file, if any is found. Searches the current path after adding likely places where GSAS-II might install svn.
Returns: None if svn is not found or an absolute path to the subversion executable file.
## 4.2. GSASIIlog: Logging of “Actions”¶
Module to provide logging services, e.g. track and replay “actions” such as menu item, tree item, button press, value change and so on.
This capability is not currently implemented, but might be resurrected in some future version of GSAS-II.
GSASIIlog.ButtonBindingLookup = {}
Lookup table for button objects
class GSASIIlog.ButtonLogEntry(locationcode, label)[source]
Object to track button press
GSASIIlog.G2logList = [None]
Contains a list of logged actions; first item is ignored
GSASIIlog.InvokeMenuCommand(id, G2frame, event)[source]
Called when a menu item is used to log the action as well as call the routine “bind”ed to that menu item
class GSASIIlog.LogEntry[source]
Base class to define logging objects. These store information on events in a manner that can be pickled and saved – direct references to wx objects is not allowed.
Each object must define:
• __init__: stores the information needed to log & later recreate the action
• __str__ : shows a nice ASCII string for each action
• Replay: recreates the action when the log is played
optional:
• Repaint: redisplays the current window
GSASIIlog.LogInfo = {'LastPaintAction': None, 'Logging': False, 'Tree': None}
Contains values that are needed in the module for past actions & object location
GSASIIlog.LogOff()[source]
Turn Off logging of actions
GSASIIlog.LogOn()[source]
Turn On logging of actions
GSASIIlog.LogVarChange(result, key)[source]
Called when a variable is changed to log that action
GSASIIlog.MakeButtonLog(locationcode, label)[source]
Create a ButtonLogEntry action log
GSASIIlog.MakeTabLog(title, tabname)[source]
Create a TabLogEntry action log
GSASIIlog.MakeTreeLog(textlist)[source]
Create a TreeLogEntry action log
GSASIIlog.MenuBindingLookup = {}
class GSASIIlog.MenuLogEntry(menulabellist)[source]
object that tracks when a menu command is executed
Replay()[source]
GSASIIlog.OnReplayPress(event)[source]
execute one or more commands when the replay button is pressed
GSASIIlog.ReplayLog(event)[source]
replay the logged actions
GSASIIlog.SaveMenuCommand(id, G2frame, handler)[source]
Creates a table of menu items and their pseudo-bindings
GSASIIlog.ShowLogStatus()[source]
Return the logging status
class GSASIIlog.TabLogEntry(title, tabname)[source]
Object to track when tabs are pressed in the DataFrame window
Repaint()[source]
Used to redraw a window created in response to a Tab press
Replay()[source]
Perform a Tab press action when read from the log
class GSASIIlog.TreeLogEntry(itemlist)[source]
Object to track when tree items are pressed in the main window
Repaint()[source]
Used to redraw a window created in response to a click on a data tree item
Replay()[source]
Perform a Tree press action when read from the log
class GSASIIlog.VarLogEntry(treeRefs, indexRefs, value)[source]
object that tracks changes to a variable
Replay()[source]
Perform a Variable Change action, when read from the log
class GSASIIlog.dictLogged(obj, treeRefs, indexRefs=[])[source]
A version of a dict object that tracks the source of the object back to the location on the G2 tree. If a list (tuple) or dict are pulled from inside this object the source information is appended to the provinance tracking lists.
tuples are converted to lists.
class GSASIIlog.listLogged(obj, treeRefs, indexRefs=[])[source]
A version of a list object that tracks the source of the object back to the location on the G2 tree. If a list (tuple) or dict are pulled from inside this object the source information is appended to the provinance tracking lists.
tuples are converted to lists.
## 4.3. config_example.py: Configuration options¶
This file contains optional configuration options for GSAS-II. The variables in this file can be copied to file config.py, which is imported if present. Access these variables using GSASIIpath.GetConfigValue(), which returns None if the variable is not set. Note that a config.py file need not be present, but if in use it will typically be found with the GSAS-II source directory (GSASIIpath.Path2GSAS2) or a directory for local GSAS-II modifications (~/.G2local/ or /Documents and Settings/<User>/.G2local/). Note that the contents of config.py is usually changed using GSASIIctrlGUI.SelectConfigSetting.
When defining new config variables for GSAS-II, define them here with a default value: use None or a string for strings, or use integers or real values. Include a doc string after each variable is defined to explain what it does. Use names ending in _location or _directory for items that will contain directory names. Use names ending in _exec for executable files (.exe on windows).
For example:
test_int = 0
test_float = 0.0
test_string = None (or)
test_string = 'value'
config_example.Arc_mask_azimuth = 10.0
Specifies the default azimuthal range for creation of arc masks. Default is 10.0 degrees 2-theta.
config_example.Autoint_PollTime = 30.0
Specifies the frequency, in seconds that AutoInt checks for new files. Default is 30 seconds
config_example.Autoscale_ParmNames = ['userComment2', 'extraInputs\\1\\extraInputs', 'Ion_Chamber_I0']
Gives the possible selection of incident monitor names as found in an image metadata file. Used in AutoIntegration
config_example.Clip_on = True
if True then line plots willl be clipped at plot border; if False line plots extend nto white space around plot frme
config_example.Column_Metadata_directory = None
When specified and when images are read, GSAS-II will read metadata from a 1-ID style .par and a .EXT_lbls (EXT = image extension) or .lbls file. See GSASIIfiles.readColMetadata() for information on how this is done.
config_example.Contour_color = 'GSPaired'
Specifies the color map to be used for contour plots (images, pole figures, etc.) will be applied for new images and if Saved for a new start of GSAS-II
config_example.DefaultAutoScale = 'userComment2'
DefaultAutoScale selects one of the AutoScale_ParmNames. Used in AutoIntegration
config_example.DrawAtoms_default = ''
Allows selection of the default plotting mode for structures in Draw Atoms. The only valid values are: ‘lines’, ‘vdW balls’, ‘sticks’, ‘balls & sticks’, ‘ellipsoids’. %% If a non-valid choice is used (the default) ‘vdW balls’ is used.
config_example.Enable_logging = False
Set to True to enable use of command logging (under development.)
config_example.G2RefinementWindow = False
When True a custom progress window is displayed to track the progress of refinements. When False a generic wxpython supplied progress dialog is used.
config_example.Help_mode = 'browser'
Set to “internal” to use a Python-based web viewer to display help documentation and tutorials. If set to the default (“browser”) the default web browser is used.
config_example.Image_2theta_max = 50.0
Specifies a default 2-theta maximum used for calibration and integration as the Outer 2-theta value. Will be applied for newly-read images, but if changed the new value will be saved.
config_example.Image_2theta_min = 5.0
Specifies a default 2-theta minimum used for calibration and integration as the Inner 2-theta value. Will be applied for newly-read images, but if changed the new value will be saved.
config_example.Image_calibrant = ''
Specifies a default calibrant material for images. Will be applied for newly-read images, but if changed the specified material will be saved.
config_example.Import_directory = None
Specifies a default location for importing (reading) input files. Will be updated if Save_paths is True. Note that os.path.expanduser is run on this before it is used, so the user’s home directory can be specified with a ‘~’.
config_example.Instprm_default = False
when True, GSAS-II instprm file are shown as default; when False, old GSAS stype prm, etc files are default
config_example.Main_Pos = '(100,100)'
Main window location - will be updated & saved when user moves it. If position is outside screen then it will be repositioned to default
config_example.Main_Size = '(700,450)'
Main window size (width, height) - initially uses wx.DefaultSize but will updated and saved as the user changes the window
config_example.Movie_fps = 10
Specifies movie frames-per-second; larger number will make smoother modulation movies but larger files.
config_example.Movie_time = 5
Specifices time in sec for one modulation loop; larger number will give more frames for same fps’
config_example.Multiprocessing_cores = 0
Specifies the number of cores to use when performing multicore computing. A number less than zero causes the recommended number of cores [using multiprocessing.cpu_count()/2] to be used. Setting this number to 0 or 1 avoids use of the multiprocessing module: all computations are performed in-line.
config_example.PDF_Rmax = 100.0
Maximum radius for G(r) calculations: range is from 10-200A; default is 100A
config_example.Plot_Colors = 'k r g b m c'
The colors for line plots: use one of ‘k’-black, ‘r’-red, ‘b’-blue, ‘g’-green, ‘m’-magenta, ‘c’-cyan for the line colors in order of obs., calc., back., diff., color5 & color6 separated by spaces; 6 items required.
config_example.Plot_Pos = '(200,200)'
Plot window location - will be updated & saved when user moves it these widows. If position is outside screen then it will be repositioned to default
config_example.Plot_Size = '(700,600)'
Plot window size (width, height) - initially uses wx.DefaultSize but will updated and saved as the user changes the window
config_example.Ring_mask_thickness = 0.1
Specifies the default thickness for creation of ring and arc masks. Default is 0.1 degrees 2-theta.
config_example.Save_paths = False
When set to True, the last-used path for saving of .gpx and for importing of input files is saved in the configuration file. Note that since this causes the config.py file to be updated whenever files are saved/imported, any temporary config settings can be saved to disk at that point.
config_example.SeparateHistPhaseTreeItem = False
When this is set to True, the parameters for each histogram in each phase are placed in a separate 1st-level tree item rather than in the Data tab for each phase. Requires GSAS-II be restarted to take effect. Default is False.
This option is under development and is not fully tested.
config_example.Show_timing = False
If True, shows various timing results.
config_example.Spot_mask_diameter = 1.0
Specifies the default diameter for creation of spot masks. Default is 1.0 mm
config_example.Starting_directory = None
Specifies a default location for starting GSAS-II and where .gpx files should be read from. Will be updated if Save_paths is True. Note that os.path.expanduser is run on this before it is used, so the user’s home directory can be specified with a ‘~’.
config_example.Tick_length = 8.0
Specifies the length of phase tick marks in pixels. Default is 8.
config_example.Tick_width = 1.0
Specifies the width of phase tick marks in pixels. Fractional values do seem to produce an effect. Default is 1.
config_example.Transpose = False
Set to True to cause images to be Transposed when read (for code development)
config_example.Tutorial_location = None
Change this to place tutorials by in a different spot. If None, this defaults to <user>/My Documents/G2tutorials (on windows) or <user>/G2tutorials. If you want to use a different location, this can be set here. To install into the location where GSAS-II is installed, use this:
Tutorial_location = GSASIIpath.path2GSAS2
As another example, to use ~/.G2tutorials do this:
Tutorial_location = '~/.G2tutorials'
Note that os.path.expanduser is run on Tutorial_location before it is used. Also note that GSASIIpath is imported inside config.py; other imports should be avoided.
config_example.debug = False
Set to True to turn on debugging mode. This enables use of IPython on exceptions and on calls to GSASIIpath.IPyBreak() or breakpoint(). Calls to GSASIIpath.pdbBreak() will invoke pdb at that location. %% If debug is False, calls to GSASIIpath.IPyBreak(), breakpoint() and GSASIIpath.pdbBreak() are ignored. %% From inside Spyder, calls to breakpoint() invoke the Spyder debugger, independent of the setting of debug. %% Restart GSAS-II for the setting of debug to take effect.
config_example.enum_DrawAtoms_default = ['', 'lines', 'vdW balls', 'sticks', 'balls & sticks', 'ellipsoids']
choices for DrawAtoms_default
config_example.fullIntegrate = True
If True then full image integration is default; False otherwise
config_example.fullrmc_exec = None
Defines the full path to a Python executable that has been configured with the fullrmc package. If None (the default), GSAS-II will see if fullrmc can be imported into the current Python and if not a executable named fullrmc* (or fullrmc*.exe on Windows) can be found in the GSAS-II binary directory or in the system path.
config_example.lastUpdateNotice = 0
Defines the version number for the last update notice that has been shown. This should not need to be changed manually.
config_example.logging_debug = False
Set to True to enable debug for logging (under development.)
config_example.pdffit2_exec = None
Defines the full path to a Python executable that has been configured with the PDFfit2 (diffpy) package. If None (the default), GSAS-II will see if PDFfit2 can be imported into the current Python.
config_example.previous_GPX_files = []
A list of previously used .gpx files
config_example.show_gpxSize = False
When True, the sizes of the sections of the GPX file are listed when the GPX file is opened. Default is False.
config_example.svn_exec = None
Defines the full path to a subversion executable. If None (the default), GSAS-II will search for a svn or svn.exe file in the current path or in the location where the current Python is located.
config_example.wxInspector = False
If set to True, the wxInspector widget is displayed when GSAS-II is started.
## 4.4. GSASIIElem: functions for element types¶
GSASIIElem.CheckElement(El)[source]
Check if element El is in the periodic table
Parameters: El (str) – One or two letter element symbol, capitaliztion ignored True if the element is found
GSASIIElem.ComptonFac(El, SQ)[source]
compute Compton scattering factor
Parameters: El – element dictionary SQ – (sin-theta/lambda)**2 compton scattering factor
GSASIIElem.FPcalc(Orbs, KEv)[source]
Compute real & imaginary resonant X-ray scattering factors
Parameters: Orbs – list of orbital dictionaries as defined in GetXsectionCoeff KEv – x-ray energy in keV C: (f’,f”,mu): real, imaginary parts of resonant scattering & atomic absorption coeff.
GSASIIElem.FixValence(El)[source]
Returns the element symbol, even when a valence is present
GSASIIElem.GetAtomInfo(El, ifMag=False)[source]
GSASIIElem.GetBLtable(General)[source]
returns a dictionary of neutron scattering length data for atom types & isotopes found in General
Parameters: General (dict) – dictionary of phase info.; includes AtomTypes & Isotopes BLtable, dictionary of scattering length data; key is atom type
GSASIIElem.GetEFFtable(atomTypes)[source]
returns a dictionary of electron form factor data for atom types found in atomTypes might not be needed?
Parameters: atomTypes (list) – list of atom types FFtable, dictionary of form factor data; key is atom type
GSASIIElem.GetEFormFactorCoeff(El)[source]
Read electron form factor coefficients from atomdata.py file
Parameters: El (str) – element 1-2 character symbol, case irrevelant FormFactors: list of form factor dictionaries
Each electrn form factor dictionary is:
• Symbol: 4 character element symbol (no valence)
• Z: atomic number
• fa: 5 A coefficients
• fb: 5 B coefficients
GSASIIElem.GetFFC5(ElSym)[source]
Get 5 term form factor and Compton scattering data
Parameters: ElSym – str(1-2 character element symbol with proper case); dictionary with 5 term form factor & compton coefficients
GSASIIElem.GetFFtable(atomTypes)[source]
returns a dictionary of form factor data for atom types found in atomTypes
Parameters: atomTypes (list) – list of atom types FFtable, dictionary of form factor data; key is atom type
GSASIIElem.GetFormFactorCoeff(El)[source]
Read X-ray form factor coefficients from atomdata.py file
Parameters: El (str) – element 1-2 character symbol, case irrevelant FormFactors: list of form factor dictionaries
Each X-ray form factor dictionary is:
• Symbol: 4 character element symbol with valence (e.g. ‘NI+2’)
• Z: atomic number
• fa: 4 A coefficients
• fb: 4 B coefficients
• fc: C coefficient
GSASIIElem.GetMFtable(atomTypes, Landeg)[source]
returns a dictionary of magnetic form factor data for atom types found in atomTypes
Parameters: atomTypes (list) – list of atom types Landeg (list) – Lande g factors for atomTypes FFtable, dictionary of form factor data; key is atom type
GSASIIElem.GetMagFormFacCoeff(El)[source]
Read magnetic form factor data from atmdata.py
Parameters: El – 2 character element symbol MagFormFactors: list of all magnetic form factors dictionaries for element El.
each dictionary contains:
• ‘Symbol’:Symbol
• ‘Z’:Z
• ‘mfa’: 4 MA coefficients
• ‘nfa’: 4 NA coefficients
• ‘mfb’: 4 MB coefficients
• ‘nfb’: 4 NB coefficients
• ‘mfc’: MC coefficient
• ‘nfc’: NC coefficient
GSASIIElem.GetXsectionCoeff(El)[source]
Read atom orbital scattering cross sections for fprime calculations via Cromer-Lieberman algorithm
Parameters: El – 2 character element symbol Orbs: list of orbitals each a dictionary with detailed orbital information used by FPcalc
each dictionary is:
• ‘OrbName’: Orbital name read from file
• ‘IfBe’ 0/2 depending on orbital
• ‘BindEn’: binding energy
• ‘BB’: BindEn/0.02721
• ‘XSectIP’: 5 cross section inflection points
• ‘ElEterm’: energy correction term
• ‘SEdge’: absorption edge for orbital
• ‘Nval’: 10/11 depending on IfBe
• ‘LEner’: 10/11 values of log(energy)
• ‘LXSect’: 10/11 values of log(cross section)
GSASIIElem.MagScatFac(El, SQ)[source]
compute value of form factor
Parameters: El – element dictionary defined in GetFormFactorCoeff SQ – (sin-theta/lambda)**2 gfac – Lande g factor (normally = 2.0) real part of form factor
GSASIIElem.ScatFac(El, SQ)[source]
compute value of form factor
Parameters: El – element dictionary defined in GetFormFactorCoeff SQ – (sin-theta/lambda)**2 real part of form factor
GSASIIElem.SetupGeneral(data, dirname)[source]
Initialize the General sections of the Phase tree contents Called by SetupGeneral in GSASIIphsGUI and in GSASIIscriptable.SetupGeneral
GSASIIElem.getBLvalues(BLtables, ifList=False)[source]
Needs a doc string
GSASIIElem.getFFvalues(FFtables, SQ, ifList=False)[source]
Needs a doc string
GSASIIElem.getMFvalues(MFtables, SQ, ifList=False)[source]
Needs a doc string
## 4.5. GSASIIlattice: Unit cells¶
Perform lattice-related computations
Note that G is the reciprocal lattice tensor, and g is its inverse, $$G = g^{-1}$$, where
$\begin{split}g = \left( \begin{matrix} a^2 & a b\cos\gamma & a c\cos\beta \\ a b\cos\gamma & b^2 & b c \cos\alpha \\ a c\cos\beta & b c \cos\alpha & c^2 \end{matrix}\right)\end{split}$
The “A tensor” terms are defined as $$A = (\begin{matrix} G_{11} & G_{22} & G_{33} & 2G_{12} & 2G_{13} & 2G_{23}\end{matrix})$$ and A can be used in this fashion: $$d^* = \sqrt {A_0 h^2 + A_1 k^2 + A_2 l^2 + A_3 hk + A_4 hl + A_5 kl}$$, where d is the d-spacing, and $$d^*$$ is the reciprocal lattice spacing, $$Q = 2 \pi d^* = 2 \pi / d$$. Note that GSAS-II variables p::Ai (i = 0, 1,… 5) and p is a phase number are used for the Ai values. See A2cell(), cell2A() for interconversion between A and unit cell parameters; cell2Gmat() Gmat2cell() for G and cell parameters.
When the hydrostatic/elastic strain coefficients (Dij, $$D_{ij}$$) are used, they are added to the A tensor terms (Ai, $$A_{i}$$) so that A is redefined $$A = (\begin{matrix} A_{0} + D_{11} & A_{1} + D_{22} & A_{2} + D_{33} & A_{3} + D_{12} & A_{4} + D_{13} & A_{5} + D_{23}\end{matrix})$$. See cellDijFill(). Note that GSAS-II variables p:h:Dij (i,j = 1, 2, 3) and p is a phase number and h a histogram number are used for the Dij values.
GSASIIlattice.A2Gmat(A, inverse=True)[source]
Fill real & reciprocal metric tensor (G) from A.
Parameters: A – reciprocal metric tensor elements as [G11,G22,G33,2*G12,2*G13,2*G23] inverse (bool) – if True return both G and g; else just G reciprocal (G) & real (g) metric tensors (list of two numpy 3x3 arrays)
GSASIIlattice.A2cell(A)[source]
Compute unit cell constants from A
Parameters: A – [G11,G22,G33,2*G12,2*G13,2*G23] G - reciprocal metric tensor a,b,c,alpha, beta, gamma (degrees) - lattice parameters
GSASIIlattice.A2invcell(A)[source]
Compute reciprocal unit cell constants from A returns tuple with a*,b*,c*,alpha*, beta*, gamma* (degrees)
GSASIIlattice.AplusDij(A, Dij, SGData)[source]
returns the A corrected by Dij
Parameters: Returns list newA: A (list) – reciprocal metric terms A0-A5 Dij (array) – unique Dij values as stored in Hstrain SGdata (dict) – a symmetry object A corrected by Dij
GSASIIlattice.CellAbsorption(ElList, Volume)[source]
Compute unit cell absorption
Parameters: ElList (dict) – dictionary of element contents including mu and number of atoms be cell Volume (float) – unit cell volume mu-total/Volume
GSASIIlattice.CellBlock(nCells)[source]
Generate block of unit cells n*n*n on a side; [0,0,0] centered, n = 2*nCells+1 currently only works for nCells = 0 or 1 (not >1)
GSASIIlattice.CellDijCorr(Cell, SGData, Data, hist)[source]
Returns the cell corrected for Dij values.
Parameters: Cell (list) – lattice parameters SGdata (dict) – a symmetry object Data (dict) – phase data structure; contains set of Dij values hist (str) – histogram name cell corrected for Dij values
GSASIIlattice.CentCheck(Cent, H)[source]
needs doc string
GSASIIlattice.CosAngle(U, V, G)[source]
calculate cos of angle between U & V in generalized coordinates defined by metric tensor G
Parameters: U – 3-vectors assume numpy arrays, can be multiple reflections as (N,3) array V – 3-vectors assume numpy arrays, only as (3) vector G – metric tensor for U & V defined space assume numpy array cos(phi)
GSASIIlattice.CosSinAngle(U, V, G)[source]
calculate sin & cos of angle between U & V in generalized coordinates defined by metric tensor G
Parameters: U – 3-vectors assume numpy arrays V – 3-vectors assume numpy arrays G – metric tensor for U & V defined space assume numpy array cos(phi) & sin(phi)
GSASIIlattice.CrsAng(H, cell, SGData)[source]
needs doc string
GSASIIlattice.CubicSHarm(L, M, Th, Ph)[source]
Calculation of the cubic harmonics given in Table 3 in M.Kara & K. Kurki-Suonio, Acta Cryt. A37, 201 (1981). For L = 14,20 only for m3m from F.M. Mueller and M.G. Priestley, Phys Rev 148, 638 (1966)
Parameters: Returns klm value/array: L (int) – degree of the harmonic (L >= 0) M (int) – order number [|M| <= L] Th (float/array) – Azimuthal coordinate 0 <= Th <= 360 Ph (float/array) – Polar coordinate 0<= Ph <= 180 cubic harmonics
GSASIIlattice.Dsp2pos(Inst, dsp)[source]
convert d-spacing to powder pattern position (2-theta or TOF, musec)
GSASIIlattice.FindNonstandard(controls, Phase)[source]
Find nonstandard setting of magnetic cell that aligns with parent nuclear cell
Parameters: controls – list unit cell indexing controls Phase – dict new magnetic phase data (NB:not G2 phase construction); modified here None
GSASIIlattice.Flnh(SHCoef, phi, beta, SGData)[source]
needs doc string
GSASIIlattice.GenCellConstraints(Trans, origPhase, newPhase, origA, oSGLaue, nSGLaue, debug=False)[source]
Generate the constraints between two unit cells constants for a phase transformed by matrix Trans.
Parameters: Trans (np.array) – a 3x3 direct cell transformation matrix where, Trans = np.array([ [2/3, 4/3, 1/3], [-1, 0, 0], [-1/3, -2/3, 1/3] ]) (for a’ = 2/3a + 4/3b + 1/3c; b’ = -a; c’ = -1/3, -2/3, 1/3) origPhase (int) – phase id (pId) for original phase newPhase (int) – phase id for the transformed phase to be constrained from original phase origA (list) – reciprocal cell (“A*”) tensor (used for debug only) oSGLaue (dict) – space group info for original phase nSGLaue (dict) – space group info for transformed phase debug (bool) – If true, the constraint input is used to compute and print A* and from that the direct cell for the transformed phase.
GSASIIlattice.GenHBravais(dmin, Bravais, A, cctbx_args=None)[source]
Generate the positionally unique powder diffraction reflections
Parameters: dmin – minimum d-spacing in A Bravais – lattice type (see GetBraviasNum). Bravais is one of: 0 F cubic 1 I cubic 2 P cubic 3 R hexagonal (trigonal not rhombohedral) 4 P hexagonal 5 I tetragonal 6 P tetragonal 7 F orthorhombic 8 I orthorhombic 9 A orthorhombic 10 B orthorhombic 11 C orthorhombic 12 P orthorhombic 13 I monoclinic 14 A monoclinic 15 C monoclinic 16 P monoclinic 17 P triclinic A – reciprocal metric tensor elements as [G11,G22,G33,2*G12,2*G13,2*G23] cctbx_args (dict) – items defined in CCTBX: ’sg_type’: value from cctbx.sgtbx.space_group_type(symmorphic_sgs[ibrav]) ’uctbx_unit_cell’: pointer to cctbx.uctbx.unit_cell() ’miller_index_generator’: pointer to cctbx.miller.index_generator() HKL unique d list of [h,k,l,d,-1] sorted with largest d first
GSASIIlattice.GenHLaue(dmin, SGData, A)[source]
Generate the crystallographically unique powder diffraction reflections for a lattice and Bravais type
Parameters: dmin – minimum d-spacing SGData – space group dictionary with at least ’SGLaue’: Laue group symbol: one of ‘-1’,’2/m’,’mmm’,’4/m’,’6/m’,’4/mmm’,’6/mmm’, ‘3m1’, ‘31m’, ‘3’, ‘3R’, ‘3mR’, ‘m3’, ‘m3m’ ’SGLatt’: lattice centering: one of ‘P’,’A’,’B’,’C’,’I’,’F’ ’SGUniq’: code for unique monoclinic axis one of ‘a’,’b’,’c’ (only if ‘SGLaue’ is ‘2/m’) otherwise an empty string A – reciprocal metric tensor elements as [G11,G22,G33,2*G12,2*G13,2*G23] HKL = list of [h,k,l,d] sorted with largest d first and is unique part of reciprocal space ignoring anomalous dispersion
GSASIIlattice.GenPfHKLs(nMax, SGData, A)[source]
Generate the unique pole figure reflections for a lattice and Bravais type. Min d-spacing=1.0A & no more than nMax returned
Parameters: nMax – maximum number of hkls returned SGData – space group dictionary with at least ’SGLaue’: Laue group symbol: one of ‘-1’,’2/m’,’mmm’,’4/m’,’6/m’,’4/mmm’,’6/mmm’, ‘3m1’, ‘31m’, ‘3’, ‘3R’, ‘3mR’, ‘m3’, ‘m3m’ ’SGLatt’: lattice centering: one of ‘P’,’A’,’B’,’C’,’I’,’F’ ’SGUniq’: code for unique monoclinic axis one of ‘a’,’b’,’c’ (only if ‘SGLaue’ is ‘2/m’) otherwise an empty string A – reciprocal metric tensor elements as [G11,G22,G33,2*G12,2*G13,2*G23] HKL = list of ‘h k l’ strings sorted with largest d first; no duplicate zones
GSASIIlattice.GenRBCoeff(sytsym, L)[source]
needs doc string
GSASIIlattice.GenSHCoeff(SGLaue, SamSym, L, IfLMN=True)[source]
needs doc string
GSASIIlattice.GenSSHLaue(dmin, SGData, SSGData, Vec, maxH, A)[source]
needs a doc string
GSASIIlattice.GenerateCellConstraints()[source]
Generate unit cell constraints for transforming one set of A tensor values to another using symbolic math (requires the sympy package)
Note that this is only used to do the symbolic math needed to generate cell relationships. It is not used normally in GSAS-II.
GSASIIlattice.GetBraviasNum(center, system)[source]
Determine the Bravais lattice number, as used in GenHBravais
Parameters: center – one of: ‘P’, ‘C’, ‘I’, ‘F’, ‘R’ (see SGLatt from GSASIIspc.SpcGroup) system – one of ‘cubic’, ‘hexagonal’, ‘tetragonal’, ‘orthorhombic’, ‘trigonal’ (for R) ‘monoclinic’, ‘triclinic’ (see SGSys from GSASIIspc.SpcGroup) a number between 0 and 13 or throws a ValueError exception if the combination of center, system is not found (i.e. non-standard)
GSASIIlattice.GetKcl(L, N, SGLaue, phi, beta)[source]
needs doc string
GSASIIlattice.GetKclKsl(L, N, SGLaue, psi, phi, beta)[source]
This is used for spherical harmonics description of preferred orientation;
cylindrical symmetry only (M=0) and no sample angle derivatives returned
GSASIIlattice.GetKsl(L, M, SamSym, psi, gam)[source]
needs doc string
GSASIIlattice.Glnh(SHCoef, psi, gam, SamSym)[source]
needs doc string
GSASIIlattice.Gmat2A(G)[source]
Extract A from reciprocal metric tensor (G)
Parameters: G – reciprocal maetric tensor (3x3 numpy array A = [G11,G22,G33,2*G12,2*G13,2*G23]
GSASIIlattice.Gmat2AB(G)[source]
Computes orthogonalization matrix from reciprocal metric tensor G
Returns: tuple of two 3x3 numpy arrays (A,B) A for crystal to Cartesian transformations (A*x = np.inner(A,x) = X) B (= inverse of A) for Cartesian to crystal transformation (B*X = np.inner(B,X) = x)
GSASIIlattice.Gmat2cell(g)[source]
Compute real/reciprocal lattice parameters from real/reciprocal metric tensor (g/G) The math works the same either way.
Parameters: (or G) (g) – real (or reciprocal) metric tensor 3x3 array a,b,c,alpha, beta, gamma (degrees) (or a*,b*,c*,alpha*,beta*,gamma* degrees)
GSASIIlattice.H2ThPh(H, Bmat, Q)[source]
Convert HKL to spherical polar & azimuth angles
GSASIIlattice.HKL2SpAng(H, cell, SGData)[source]
Computes spherical coords for hkls; view along 001
Parameters: H (array) – arrays of hkl cell (tuple) – a,b,c, alpha, beta, gamma (degrees) SGData (dict) – space group dictionary arrays of r,phi,psi (radius,inclination,azimuth) about 001
GSASIIlattice.Hx2Rh(Hx)[source]
needs doc string
GSASIIlattice.LaueUnique(Laue, HKLF)[source]
Impose Laue symmetry on hkl
Parameters: Laue (str) – Laue symbol, as below centrosymmetric Laue groups: ['-1','2/m','112/m','2/m11','mmm','-42m','-4m2','4/mmm','-3','-3m', '-31m','-3m1','6/m','6/mmm','m3','m3m'] noncentrosymmetric Laue groups: ['1','2','211','112','m','m11','11m','222','mm2','m2m','2mm', '4','-4','422','4mm','3','312','321','3m','31m','3m1','6','-6', '622','6mm','-62m','-6m2','23','432','-43m'] HKLF – np.array([[h,k,l,…]]) reflection set to be converted HKLF new reflection array with imposed Laue symmetry
GSASIIlattice.LaueUnique2(SGData, refList)[source]
Impose Laue symmetry on hkl
Parameters: SGData – space group data from ‘P ‘+Laue HKLF – np.array([[h,k,l,…]]) reflection set to be converted HKLF new reflection array with imposed Laue symmetry
GSASIIlattice.MaxIndex(dmin, A)[source]
needs doc string
GSASIIlattice.OdfChk(SGLaue, L, M)[source]
finds symmetry rules for spherical harmonic coefficients for Laue groups :param str SGLaue: Laue symbol :param int L: principal harmonic term; only evens are used :param int M: second harmonic term; can be -L <= M <= L :returns True if allowed
GSASIIlattice.PlaneIntercepts(Amat, H, phase, stack)[source]
find unit cell intercepts for a stack of hkl planes
GSASIIlattice.Pos2dsp(Inst, pos)[source]
convert powder pattern position (2-theta or TOF, musec) to d-spacing is currently only approximate for EDX data; accurate for others.
GSASIIlattice.RBChk(sytsym, L, M)[source]
finds symmetry rules for spherical harmonic coefficients for site symmetries :param str SGLaue: Laue symbol or sytsym symbol :param int L: principal harmonic term; only evens are used :param int M: second harmonic term; can be -L <= M <= L :returns True if allowed and sign for term NB: not complete for all site symmetries! Many are missing
GSASIIlattice.RBsymCheck(Atoms, ct, cx, cs, AtLookUp, Amat, RBObjIds, SGData)[source]
Checks members of a rigid body to see if one is a symmetry equivalent of another. If so the atom site frac is set to zero.
Parameters: Atoms – atom array as defined in GSAS-II; modified here ct – int location of atom type in Atoms item cx – int location of x,y,z,frac in Atoms item AtLookUp (dict) – atom lookup by Id table Amat (np.array) – crystal-to-Cartesian transformation matrix RBObjIds (list) – atom Id belonging to rigid body being tested SGData (dict) – GSAS-II space group info. Atoms with modified atom frac entries
GSASIIlattice.RBsymChk(RBsym, coefNames)[source]
imposes rigid body symmetry on spherical harmonics terms Key problem is noncubic RB symmetries in cubic site symmetries & vice versa.
GSASIIlattice.Rh2Hx(Rh)[source]
needs doc string
GSASIIlattice.SHarmcal(SytSym, SHFln, psi, gam)[source]
Perform a surface spherical harmonics computation. Note that the the number of gam values must either be 1 or must match psi
Parameters: Returns array SHVal: SytSym (str) – sit symmetry - only looking for cubics SHFln (dict) – spherical harmonics coefficients; key has L & M psi (float/array) – Azimuthal coordinate 0 <= Th <= 360 gam (float/array) – Polar coordinate 0<= Ph <= 180 spherical harmonics array for psi,gam values
GSASIIlattice.SamAng(Tth, Gangls, Sangl, IFCoup)[source]
Compute sample orientation angles vs laboratory coord. system
Parameters: Tth – Signed theta Gangls – Sample goniometer angles phi,chi,omega,azmuth Sangl – Sample angle zeros om-0, chi-0, phi-0 IFCoup – True if omega & 2-theta coupled in CW scan psi,gam: Sample odf angles dPSdA,dGMdA: Angle zero derivatives
GSASIIlattice.SphHarmAng(L, M, P, Th, Ph)[source]
Compute spherical harmonics values using scipy.special.sph_harm
Parameters: Returns ylmp value/array: L (int) – degree of the harmonic (L >= 0) M (int) – order number (|M| <= L) P (int) – sign flag = -1 or 1 Th (float/array) – Azimuthal coordinate 0 <= Th <= 360 Ph (float/array) – Polar coordinate 0<= Ph <= 180 as reals
GSASIIlattice.SwapIndx(Axis, H)[source]
needs doc string
GSASIIlattice.SwapItems(Alist, pos1, pos2)[source]
exchange 2 items in a list
GSASIIlattice.TOF2dsp(Inst, Pos)[source]
convert powder pattern TOF, musec to d-spacing by successive approximation Pos can be numpy array
GSASIIlattice.TransformCell(cell, Trans)[source]
Transform lattice parameters by matrix
Parameters: cell – list a,b,c,alpha,beta,gamma,(volume) Trans – array transformation matrix array transformed a,b,c,alpha,beta,gamma,volume
GSASIIlattice.TransformPhase(oldPhase, newPhase, Trans, Uvec, Vvec, ifMag, Force=True)[source]
Transform atoms from oldPhase to newPhase M’ is inv(M) does X’ = M(X-U)+V transformation for coordinates and U’ = MUM/det(M) for anisotropic thermal parameters
Parameters: oldPhase – dict G2 phase info for old phase newPhase – dict G2 phase info for new phase; with new cell & space group atoms are from oldPhase & will be transformed Trans – lattice transformation matrix M Uvec – array parent coordinates transformation vector U Vvec – array child coordinate transformation vector V ifMag – bool True if convert to magnetic phase; if True all nonmagnetic atoms will be removed newPhase dict modified G2 phase info atCodes list atom transformation codes
GSASIIlattice.U6toUij(U6)[source]
Fill matrix (Uij) from U6 = [U11,U22,U33,U12,U13,U23] NB: there is a non numpy version in GSASIIspc: U2Uij
Parameters: U6 (list) – 6 terms of u11,u22,… Uij - numpy [3][3] array of uij
GSASIIlattice.Uij2Ueqv(Uij, GS, Amat)[source]
returns 1/3 trace of diagonalized U matrix :param Uij: numpy array [Uij] :param GS: Uij too betaij conversion matrix :param Amat: crystal to Cartesian transformation matrix :returns: 1/3 trace of diagonalized U matrix :returns: True if nonpositive-definate; False otherwise
GSASIIlattice.Uij2betaij(Uij, G)[source]
Convert Uij to beta-ij tensors – stub for eventual completion
Parameters: Uij – numpy array [Uij] G – reciprocal metric tensor beta-ij - numpy array [beta-ij]
GSASIIlattice.UijtoU6(U)[source]
Fill vector [U11,U22,U33,U12,U13,U23] from Uij NB: there is a non numpy version in GSASIIspc: Uij2U
GSASIIlattice.UniqueCellByLaue = [[['m3', 'm3m'], (0,)], [['3R', '3mR'], (0, 3)], [['3', '3m1', '31m', '6/m', '6/mmm', '4/m', '4/mmm'], (0, 2)], [['mmm'], (0, 1, 2)], [['2/ma'], (0, 1, 2, 3)], [['2/mb'], (0, 1, 2, 4)], [['2/mc'], (0, 1, 2, 5)], [['-1'], (0, 1, 2, 3, 4, 5)]]
List the unique cell terms by index for each Laue class
GSASIIlattice.betaij2Uij(betaij, G)[source]
Convert beta-ij to Uij tensors
:param beta-ij - numpy array [beta-ij] :param G: reciprocal metric tensor :returns: Uij: numpy array [Uij]
GSASIIlattice.calc_V(A)[source]
Compute the real lattice volume (V) from A
GSASIIlattice.calc_rDsq(H, A)[source]
needs doc string
GSASIIlattice.calc_rDsq2(H, G)[source]
needs doc string
GSASIIlattice.calc_rDsqSS(H, A, vec)[source]
needs doc string
GSASIIlattice.calc_rDsqT(H, A, Z, tof, difC)[source]
needs doc string
GSASIIlattice.calc_rDsqTSS(H, A, vec, Z, tof, difC)[source]
needs doc string
GSASIIlattice.calc_rDsqZ(H, A, Z, tth, lam)[source]
needs doc string
GSASIIlattice.calc_rDsqZSS(H, A, vec, Z, tth, lam)[source]
needs doc string
GSASIIlattice.calc_rV(A)[source]
Compute the reciprocal lattice volume (V*) from A
GSASIIlattice.calc_rVsq(A)[source]
Compute the square of the reciprocal lattice volume (1/V**2) from A’
GSASIIlattice.cell2A(cell)[source]
Obtain A = [G11,G22,G33,2*G12,2*G13,2*G23] from lattice parameters
Parameters: cell – [a,b,c,alpha,beta,gamma] (degrees) G reciprocal metric tensor as 3x3 numpy array
GSASIIlattice.cell2AB(cell, alt=False)[source]
Computes orthogonalization matrix from unit cell constants
Parameters: cell (tuple) – a,b,c, alpha, beta, gamma (degrees) tuple of two 3x3 numpy arrays (A,B) A for crystal to Cartesian transformations A*x = np.inner(A,x) = X B (= inverse of A) for Cartesian to crystal transformation B*X = np.inner(B,X) = x
GSASIIlattice.cell2GS(cell)[source]
returns Uij to betaij conversion matrix
GSASIIlattice.cell2Gmat(cell)[source]
Compute real and reciprocal lattice metric tensor from unit cell constants
Parameters: cell – tuple with a,b,c,alpha, beta, gamma (degrees) reciprocal (G) & real (g) metric tensors (list of two numpy 3x3 arrays)
GSASIIlattice.cellAlbl = ('a', 'b', 'c', 'alpha', 'beta', 'gamma')
ASCII labels for a, b, c, alpha, beta, gamma
GSASIIlattice.cellDijFill(pfx, phfx, SGData, parmDict)[source]
Returns the filled-out reciprocal cell (A) terms from the parameter dictionaries corrected for Dij.
Parameters: pfx (str) – parameter prefix (“n::”, where n is a phase number) SGdata (dict) – a symmetry object parmDict (dict) – a dictionary of parameters A,sigA where each is a list of six terms with the A terms
GSASIIlattice.cellUlbl = ('a', 'b', 'c', 'α', 'β', 'γ')
unicode labels for a, b, c, alpha, beta, gamma
GSASIIlattice.cellUnique(SGData)[source]
Returns the indices for the unique A tensor terms based on the Laue class. Any terms that are determined from others or are zero are not included.
Parameters: SGdata (dict) – a symmetry object a list of 0 to 6 terms with indices of the unique A terms
GSASIIlattice.cellXformRelations = {0: ['1.0*A0*T[0,0]**2', '1.0*A1*T[0,1]**2', '1.0*A2*T[0,2]**2', '1.0*A3*T[0,0]*T[0,1]', '1.0*A4*T[0,0]*T[0,2]', '1.0*A5*T[0,1]*T[0,2]'], 1: ['1.0*A0*T[1,0]**2', '1.0*A1*T[1,1]**2', '1.0*A2*T[1,2]**2', '1.0*A3*T[1,0]*T[1,1]', '1.0*A4*T[1,0]*T[1,2]', '1.0*A5*T[1,1]*T[1,2]'], 2: ['1.0*A0*T[2,0]**2', '1.0*A1*T[2,1]**2', '1.0*A2*T[2,2]**2', '1.0*A3*T[2,0]*T[2,1]', '1.0*A4*T[2,0]*T[2,2]', '1.0*A5*T[2,1]*T[2,2]'], 3: ['2.0*A0*T[0,0]*T[1,0]', '2.0*A1*T[0,1]*T[1,1]', '2.0*A2*T[0,2]*T[1,2]', '1.0*A3*(T[0,0]*T[1,1] + T[1,0]*T[0,1])', '1.0*A4*(T[0,0]*T[1,2] + T[1,0]*T[0,2])', '1.0*A5*(T[0,1]*T[1,2] + T[1,1]*T[0,2])'], 4: ['2.0*A0*T[0,0]*T[2,0]', '2.0*A1*T[0,1]*T[2,1]', '2.0*A2*T[0,2]*T[2,2]', '1.0*A3*(T[0,0]*T[2,1] + T[2,0]*T[0,1])', '1.0*A4*(T[0,0]*T[2,2] + T[2,0]*T[0,2])', '1.0*A5*(T[0,1]*T[2,2] + T[2,1]*T[0,2])'], 5: ['2.0*A0*T[1,0]*T[2,0]', '2.0*A1*T[1,1]*T[2,1]', '2.0*A2*T[1,2]*T[2,2]', '1.0*A3*(T[1,0]*T[2,1] + T[2,0]*T[1,1])', '1.0*A4*(T[1,0]*T[2,2] + T[2,0]*T[1,2])', '1.0*A5*(T[1,1]*T[2,2] + T[2,1]*T[1,2])']}
cellXformRelations provide the constraints on newA[i] values for a new cell generated from oldA[i] values.
GSASIIlattice.cellZeros(SGData)[source]
Returns a list with the A terms required to be zero based on Laue symmetry
Parameters: SGdata (dict) – a symmetry object A list of six terms where the values are True if the A term must be zero, False otherwise.
GSASIIlattice.combinations(items, n)[source]
take n distinct items, order matters
GSASIIlattice.criticalEllipse(prob)[source]
Calculate critical values for probability ellipsoids from probability
GSASIIlattice.fillgmat(cell)[source]
Compute lattice metric tensor from unit cell constants
Parameters: cell – tuple with a,b,c,alpha, beta, gamma (degrees) 3x3 numpy array
GSASIIlattice.fmtCellConstraints(cellConstr)[source]
Format the cell relationships created in GenerateCellConstraints() in a format that can be used to generate constraints.
Use:
cXforms = G2lat.fmtCellConstraints(G2lat.GenerateCellConstraints())
Note that this is only used to do the symbolic math needed to generate cell relationships. It is not used normally in GSAS-II.
GSASIIlattice.getHKLmax(dmin, SGData, A)[source]
finds maximum allowed hkl for given A within dmin
GSASIIlattice.getPeakPos(dataType, parmdict, dsp)[source]
convert d-spacing to powder pattern position (2-theta, E or TOF, musec)
GSASIIlattice.invcell2Gmat(invcell)[source]
Compute real and reciprocal lattice metric tensor from reciprocal
unit cell constants
Parameters: invcell – [a*,b*,c*,alpha*, beta*, gamma*] (degrees) reciprocal (G) & real (g) metric tensors (list of two 3x3 arrays)
GSASIIlattice.invpolfcal(ODFln, SGData, phi, beta)[source]
needs doc string
GSASIIlattice.permutations(items)[source]
take all items, order matters
GSASIIlattice.polfcal(ODFln, SamSym, psi, gam)[source]
Perform a pole figure computation. Note that the the number of gam values must either be 1 or must match psi. Updated for numpy 1.8.0
GSASIIlattice.prodMGMT(G, Mat)[source]
Transform metric tensor by matrix
Parameters: G – array metric tensor Mat – array transformation matrix array new metric tensor
GSASIIlattice.rotdMat(angle, axis=0)[source]
Prepare rotation matrix for angle in degrees about axis(=0,1,2)
Parameters: angle – angle in degrees axis – axis (0,1,2 = x,y,z) about which for the rotation rotation matrix - 3x3 numpy array
GSASIIlattice.rotdMat4(angle, axis=0)[source]
Prepare rotation matrix for angle in degrees about axis(=0,1,2) with scaling for OpenGL
Parameters: angle – angle in degrees axis – axis (0,1,2 = x,y,z) about which for the rotation rotation matrix - 4x4 numpy array (last row/column for openGL scaling)
GSASIIlattice.sec2HMS(sec)[source]
Convert time in sec to H:M:S string
Parameters: sec – time in seconds H:M:S string (to nearest 100th second)
GSASIIlattice.selections(items, n)[source]
take n (not necessarily distinct) items, order matters
GSASIIlattice.selftestlist = []
Defines a list of self-tests
GSASIIlattice.sortHKLd(HKLd, ifreverse, ifdup, ifSS=False)[source]
sort reflection list on d-spacing; can sort in either order
Parameters: HKLd – a list of [h,k,l,d,…]; ifreverse – True for largest d first ifdup – True if duplicate d-spacings allowed sorted reflection list
GSASIIlattice.subVals(expr, A, T)[source]
Evaluate the symbolic expressions by substituting for A0-A5 & Tij
This can be used on the cell relationships created in GenerateCellConstraints() like this:
Trans = np.array([ [2/3, 4/3, 1/3], [-1, 0, 0], [-1/3, -2/3, 1/3] ])
T = np.linalg.inv(Trans).T
print([subVals(i,Aold,T) for i in GenerateCellConstraints()])
Parameters: expr (list) – a list of sympy expressions. A (list) – This is the A* tensor as defined above. T (np.array) – a 3x3 transformation matrix where, Trans = np.array([ [2/3, 4/3, 1/3], [-1, 0, 0], [-1/3, -2/3, 1/3] ]) (for a’ = 2/3a + 4/3b + 1/3c; b’ = -a; c’ = -1/3, -2/3, 1/3) then T = np.linalg.inv(Trans).T
Note that this is only used to do the symbolic math needed to generate cell relationships. It is not used normally in GSAS-II.
GSASIIlattice.symInner(M1, M2)[source]
Compute inner product of two square matrices with symbolic processing Use dot product because sympy does not define an inner product primitive
This requires that M1 & M2 be two sympy objects, as created in GenerateCellConstraints().
Note that this is only used to do the symbolic math needed to generate cell relationships. It is not used normally in GSAS-II.
GSASIIlattice.test1()[source]
test cell2A and A2Gmat
GSASIIlattice.test2()[source]
test Gmat2A, A2cell, A2Gmat, Gmat2cell
GSASIIlattice.test3()[source]
test invcell2Gmat
GSASIIlattice.test4()[source]
test calc_rVsq, calc_rV, calc_V
GSASIIlattice.test5()[source]
test A2invcell
GSASIIlattice.test6()[source]
test cell2AB
GSASIIlattice.test7()[source]
test GetBraviasNum(…) and GenHBravais(…)
GSASIIlattice.test8()[source]
test GenHLaue
GSASIIlattice.test9()[source]
test GenHLaue
GSASIIlattice.textureIndex(SHCoef)[source]
needs doc string
GSASIIlattice.transposeHKLF(transMat, Super, refList)[source]
Apply transformation matrix to hkl(m) param: transmat: 3x3 or 4x4 array param: Super: 0 or 1 for extra index param: refList list of h,k,l,…. return: newRefs transformed list of h’,k’,l’,,, return: badRefs list of noninteger h’,k’,l’…
GSASIIlattice.uniqueCombinations(items, n)[source]
take n distinct items, order is irrelevant
## 4.6. GSASIIspc: Space group module¶
Space group interpretation routines. Note that space group information is stored in a Space Group (SGData) object.
GSASIIspc.AllOps(SGData)[source]
Returns a list of all operators for a space group, including those for centering and a center of symmetry
Parameters: SGData – from SpcGroup() (SGTextList,offsetList,symOpList,G2oprList) where SGTextList: a list of strings with formatted and normalized symmetry operators. offsetList: a tuple of (dx,dy,dz) offsets that relate the GSAS-II symmetry operation to the operator in SGTextList and symOpList. these dx (etc.) values are added to the GSAS-II generated positions to provide the positions that are generated by the normalized symmetry operators. symOpList: a list of tuples with the normalized symmetry operations as (M,T) values (see SGOps in the Space Group object) G2oprList: a list with the GSAS-II operations for each symmetry operation as a tuple with (center,mult,opnum,opcode), where center is (0,0,0), (0.5,0,0), (0.5,0.5,0.5),…; where mult is 1 or -1 for the center of symmetry where opnum is the number for the symmetry operation, in SGOps (starting with 0) and opcode is mult*(100*icen+j+1). G2opcodes: a list with the name that GSAS-II uses for each symmetry operation (same as opcode, above)
GSASIIspc.ApplyStringOps(A, SGData, X, Uij=[])[source]
Needs a doc string
GSASIIspc.ApplyStringOpsMom(A, SGData, SSGData, Mom)[source]
Applies string operations to modulated magnetic moment components used in drawing Drawing matches Bilbao MVISUALIZE
GSASIIspc.AtomDxSymFix(Dx, SytSym, CSIX)[source]
Applies site symmetry restrictions to atom position shifts. 1st parameter value of each kind encountered is assumed to be the independent one. Needed for ISODISTORT mode shifts.
GSASIIspc.CheckSpin(isym, SGData)[source]
Check for exceptions in spin rules
GSASIIspc.ElemPosition(SGData)[source]
Under development. Object here is to return a list of symmetry element types and locations suitable for say drawing them. So far I have the element type… getting all possible locations without lookup may be impossible!
GSASIIspc.GenAtom(XYZ, SGData, All=False, Uij=[], Move=True)[source]
Generates the equivalent positions for a specified coordinate and space group
Parameters: XYZ – an array, tuple or list containing 3 elements: x, y & z SGData – from SpcGroup() All – True return all equivalent positions including duplicates; False return only unique positions Uij – [U11,U22,U33,U12,U13,U23] or [] if no Uij Move – True move generated atom positions to be inside cell False do not move atoms [[XYZEquiv],Idup,[UijEquiv],spnflp] [XYZEquiv] is list of equivalent positions (XYZ is first entry) Idup = [-][C]SS where SS is the symmetry operator number (1-24), C (if not 0,0,0) is centering operator number (1-4) and - is for inversion Cell = unit cell translations needed to put new positions inside cell [UijEquiv] - equivalent Uij; absent if no Uij given +1/-1 for spin inversion of operator - empty if not magnetic
GSASIIspc.GenHKL(HKL, SGData)[source]
Generates all equivlent reflections including Friedel pairs :param HKL: [h,k,l] must be integral values :param SGData: space group data obtained from SpcGroup :returns: array Uniq: equivalent reflections
GSASIIspc.GenHKLf(HKL, SGData)[source]
Uses old GSAS Fortran routine genhkl.for
Parameters: HKL – [h,k,l] must be integral values for genhkl.for to work SGData – space group data obtained from SpcGroup iabsnt,mulp,Uniq,phi iabsnt = True if reflection is forbidden by symmetry mulp = reflection multiplicity including Friedel pairs Uniq = numpy array of equivalent hkl in descending order of h,k,l phi = phase offset for each equivalent h,k,l
GSASIIspc.GetCSpqinel(SpnFlp, dupDir)[source]
returns Mxyz terms, multipliers, GUI flags
GSASIIspc.GetCSuinel(siteSym)[source]
returns Uij terms, multipliers, GUI flags & Uiso2Uij multipliers
GSASIIspc.GetCSxinel(siteSym)[source]
returns Xyz terms, multipliers, GUI flags
GSASIIspc.GetGenSym(SGData)[source]
Get the space group generator symbols :param SGData: from SpcGroup() LaueSym = (‘-1’,’2/m’,’mmm’,’4/m’,’4/mmm’,’3R’,’3mR’,’3’,’3m1’,’31m’,’6/m’,’6/mmm’,’m3’,’m3m’) LattSym = (‘P’,’A’,’B’,’C’,’I’,’F’,’R’)
GSASIIspc.GetKNsym(key)[source]
Needs a doc string
GSASIIspc.GetLittleGrpOps(SGData, vec)[source]
Find rotation part of operators that leave vec unchanged
Parameters: SGData – space group data structure as defined in SpcGroup above. vec – a numpy array of fractional vector coordinates Little - list of operators [M,T] that form the little gropu
GSASIIspc.GetNXUPQsym(siteSym)[source]
The codes XUPQ are for lookup of symmetry constraints for position(X), thermal parm(U) & magnetic moments (P & Q)
GSASIIspc.GetOprName(key)[source]
Needs a doc string
GSASIIspc.GetOprPtrName(key)[source]
Needs a doc string
GSASIIspc.GetOprPtrNumber(key)[source]
Needs a doc string
GSASIIspc.GetSGSpin(SGData, MSgSym)[source]
get spin generators from magnetic space group symbol
GSASIIspc.HStrainNames(SGData)[source]
Needs a doc string
GSASIIspc.Latt2text(Cen)[source]
From lattice centering vectors returns ‘;’ delimited cell centering vectors
GSASIIspc.MT2text(Opr, reverse=False)[source]
From space group matrix/translation operator returns text version
GSASIIspc.MagSSText2MTS(Opr, G2=False)[source]
From magnetic super space group cif text returns matrix/translation + spin flip
GSASIIspc.MagSytSym(SytSym, dupDir, SGData)[source]
site sym operations: 1,-1,2,3,-3,4,-4,6,-6,m need to be marked if spin inversion
GSASIIspc.MagText2MTS(mcifOpr, CIF=True)[source]
From magnetic space group cif text returns matrix/translation + spin flip
GSASIIspc.MoveToUnitCell(xyz)[source]
Translates a set of coordinates so that all values are >=0 and < 1
Parameters: xyz – a list or numpy array of fractional coordinates XYZ - numpy array of new coordinates now 0 or greater and less than 1
GSASIIspc.Muiso2Shkl(muiso, SGData, cell)[source]
this is to convert isotropic mustrain to generalized Shkls
GSASIIspc.MustrainCoeff(HKL, SGData)[source]
Needs a doc string
GSASIIspc.MustrainNames(SGData)[source]
Needs a doc string
GSASIIspc.Opposite(XYZ, toler=0.0002)[source]
Gives opposite corner, edge or face of unit cell for position within tolerance.
Result may be just outside the cell within tolerance
Parameters: XYZ – 0 >= np.array[x,y,z] > 1 as by MoveToUnitCell toler – unit cell fraction tolerance making opposite XYZ: dict of opposite positions; key=unit cell & always contains XYZ
GSASIIspc.SGErrors(IErr)[source]
Interprets the error message code from SpcGroup. Used in SpaceGroup.
Parameters: IErr – see SGError in SpcGroup() ErrString - a string with the error message or “Unknown error”
GSASIIspc.SGPrint(SGData, AddInv=False)[source]
Print the output of SpcGroup in a nicely formatted way. Used in SpaceGroup
Parameters: SGData – from SpcGroup() SGText - list of strings with the space group details SGTable - list of strings for each of the operations
GSASIIspc.SGProd(OpA, OpB)[source]
Form space group operator product. OpA & OpB are [M,V] pairs;
both must be of same dimension (3 or 4). Returns [M,V] pair
GSASIIspc.SGPtGroup(SGData)[source]
Determine point group of the space group - done after space group symbol has been evaluated by SpcGroup. Only short symbols are allowed
Parameters: SGData – from :func SpcGroup SSGPtGrp & SSGKl (only defaults for Mono & Ortho)
GSASIIspc.SGpolar(SGData)[source]
Determine identity of polar axes if any
GSASIIspc.SSChoice(SGData)[source]
Gets the unique set of possible super space groups for a given space group
GSASIIspc.SSGModCheck(Vec, modSymb, newMod=True)[source]
Checks modulation vector compatibility with supersymmetry space group symbol. if newMod: Superspace group symbol takes precidence & the vector will be modified accordingly
GSASIIspc.SSGPrint(SGData, SSGData, AddInv=False)[source]
Print the output of SSpcGroup in a nicely formatted way. Used in SSpaceGroup
Parameters: SGData – space group data structure as defined in SpcGroup above. SSGData – from SSpcGroup() SSGText - list of strings with the superspace group details SGTable - list of strings for each of the operations
GSASIIspc.SSLatt2text(SSGCen)[source]
Lattice centering vectors to text
GSASIIspc.SSMT2text(Opr)[source]
From superspace group matrix/translation operator returns text version
GSASIIspc.SSpaceGroup(SGSymbol, SSymbol)[source]
Print the output of SSpcGroup in a nicely formatted way.
Parameters: SGSymbol – space group symbol with spaces between axial fields. SSymbol – superspace group symbol extension (string). nothing
GSASIIspc.SSpcGroup(SGData, SSymbol)[source]
Determines supersymmetry information from superspace group name; currently only for (3+1) superlattices
Parameters: SGData – space group data structure as defined in SpcGroup above (see SGData). SSymbol – superspace group symbol extension (string) defining modulation direction & generator info. (SSGError,SSGData) SGError = 0 for no errors; >0 for errors (see SGErrors below for details) SSGData - is a dict (see Superspace Group object) with entries: ’SSpGrp’: full superspace group symbol, accidental spaces removed; for display only ’SSGCen’: 4D cell centering vectors [0,0,0,0] at least ’SSGOps’: 4D symmetry operations as [M,T] so that M*x+T = x’
GSASIIspc.SpaceGroup(SGSymbol)[source]
Print the output of SpcGroup in a nicely formatted way.
Parameters: SGSymbol – space group symbol (string) with spaces between axial fields nothing
GSASIIspc.SpcGroup(SGSymbol)[source]
Determines cell and symmetry information from a short H-M space group name
Parameters: SGSymbol – space group symbol (string) with spaces between axial fields (SGError,SGData) SGError = 0 for no errors; >0 for errors (see SGErrors below for details) SGData - is a dict (see Space Group object) with entries: ’SpGrp’: space group symbol, slightly cleaned up ’SGFixed’: True if space group data can not be changed, e.g. from magnetic cif; otherwise False ’SGGray’: True if 1’ in symbol - gray group for mag. incommensurate phases ’SGLaue’: one of ‘-1’, ‘2/m’, ‘mmm’, ‘4/m’, ‘4/mmm’, ‘3R’, ‘3mR’, ‘3’, ‘3m1’, ‘31m’, ‘6/m’, ‘6/mmm’, ‘m3’, ‘m3m’ ’SGInv’: boolean; True if centrosymmetric, False if not ’SGLatt’: one of ‘P’, ‘A’, ‘B’, ‘C’, ‘I’, ‘F’, ‘R’ ’SGUniq’: one of ‘a’, ‘b’, ‘c’ if monoclinic, ‘’ otherwise ’SGCen’: cell centering vectors [0,0,0] at least ’SGOps’: symmetry operations as [M,T] so that M*x+T = x’ ’SGSys’: one of ‘triclinic’, ‘monoclinic’, ‘orthorhombic’, ‘tetragonal’, ‘rhombohedral’, ‘trigonal’, ‘hexagonal’, ‘cubic’ ’SGPolax’: one of ‘ ‘, ‘x’, ‘y’, ‘x y’, ‘z’, ‘x z’, ‘y z’, ‘xyz’, ‘111’ for arbitrary axes ’SGPtGrp’: one of 32 point group symbols (with some permutations), which is filled by SGPtGroup, is external (KE) part of supersymmetry point group ’SSGKl’: default internal (Kl) part of supersymmetry point group; modified in supersymmetry stuff depending on chosen modulation vector for Mono & Ortho ’BNSlattsym’: BNS lattice symbol & cenering op - used for magnetic structures
GSASIIspc.StandardizeSpcName(spcgroup)[source]
Accept a spacegroup name where spaces may have not been used in the names according to the GSAS convention (spaces between symmetry for each axis) and return the space group name as used in GSAS
GSASIIspc.StringOpsProd(A, B, SGData)[source]
Find A*B where A & B are in strings ‘-’ + ‘100*c+n’ + ‘+ijk’ where ‘-’ indicates inversion, c(>0) is the cell centering operator, n is operator number from SgOps and ijk are unit cell translations (each may be <0). Should return resultant string - C. SGData - dictionary using entries:
• ‘SGCen’: cell centering vectors [0,0,0] at least
• ‘SGOps’: symmetry operations as [M,T] so that M*x+T = x’
GSASIIspc.SytSym(XYZ, SGData)[source]
Generates the number of equivalent positions and a site symmetry code for a specified coordinate and space group
Parameters: XYZ – an array, tuple or list containing 3 elements: x, y & z SGData – from SpcGroup a four element tuple: The 1st element is a code for the site symmetry (see GetKNsym) The 2nd element is the site multiplicity Ndup number of overlapping operators dupDir Dict - dictionary of overlapping operators
GSASIIspc.Text2MT(mcifOpr, CIF=True)[source]
From space group cif text returns matrix/translation
GSASIIspc.TextOps(text, table, reverse=False)[source]
Makes formatted operator list :param text,table: arrays of text made by SGPrint :param reverse: True for x+1/2 form; False for 1/2+x form :returns: OpText: full list of symmetry operators; one operation per line generally printed to console for use via cut/paste in other programs, but could be used for direct input
GSASIIspc.Trans2Text(Trans)[source]
from transformation matrix to text
GSASIIspc.UpdateSytSym(Phase)[source]
Update site symmetry/site multiplicity after space group/BNS lattice change
GSASIIspc.altSettingOrtho = {'A b a 2': {'abc': 'A b a 2', 'acb': 'A c 2 a', 'bac': 'B b a 2', 'bca': 'C c 2 a', 'cab': 'B 2 c b', 'cba': 'C 2 c b'}, 'A b m 2': {'abc': 'A b m 2', 'acb': 'A c 2 m', 'bac': 'B m a 2', 'bca': 'C m 2 a', 'cab': 'B 2 c m', 'cba': 'C 2 m b'}, 'A m a 2': {'abc': 'A m a 2', 'acb': 'A m 2 a', 'bac': 'B b m 2', 'bca': 'C c 2 m', 'cab': 'B 2 m b', 'cba': 'C 2 c m'}, 'A m m 2': {'abc': 'A m m 2', 'acb': 'A m 2 m', 'bac': 'B m m 2', 'bca': 'C m 2 m', 'cab': 'B 2 m m', 'cba': 'C 2 m m'}, 'C 2 2 2': {'abc': 'C 2 2 2', 'acb': 'B 2 2 2', 'bac': 'C 2 2 2', 'bca': 'B 2 2 2', 'cab': 'A 2 2 2', 'cba': 'A 2 2 2'}, 'C 2 2 21': {'abc': 'C 2 2 21', 'acb': 'B 2 21 2', 'bac': 'C 2 2 21', 'bca': 'B 2 21 2', 'cab': 'A 21 2 2', 'cba': 'A 21 2 2'}, 'C c c 2': {'abc': 'C c c 2', 'acb': 'B b 2 b', 'bac': 'C c c 2', 'bca': 'B b 2 b', 'cab': 'A 2 a a', 'cba': 'A 2 a a'}, 'C c c a': {'abc': 'C c a a', 'acb': 'B b a b', 'bac': 'C c c b', 'bca': 'B b c b', 'cab': 'A b a a', 'cba': 'A c a a'}, 'C c c m': {'abc': 'C c c m', 'acb': 'B b m b', 'bac': 'C c c m', 'bca': 'B b m b', 'cab': 'A m a a', 'cba': 'A m a a'}, 'C m c 21': {'abc': 'C m c 21', 'acb': 'B m 21 b', 'bac': 'C c m 21', 'bca': 'B b 21 m', 'cab': 'A 21 m a', 'cba': 'A 21 a m'}, 'C m c a': {'abc': 'C m c a', 'acb': 'B m a b', 'bac': 'C c m b', 'bca': 'B b c m', 'cab': 'A b m a', 'cba': 'A c a m'}, 'C m c m': {'abc': 'C m c m', 'acb': 'B m m b', 'bac': 'C c m m', 'bca': 'B b m m', 'cab': 'A m m a', 'cba': 'A m a m'}, 'C m m 2': {'abc': 'C m m 2', 'acb': 'B m 2 m', 'bac': 'C m m 2', 'bca': 'B m 2 m', 'cab': 'A 2 m m', 'cba': 'A 2 m m'}, 'C m m a': {'abc': 'C m m a', 'acb': 'B m a m', 'bac': 'C m m b', 'bca': 'B m c m', 'cab': 'A b m m', 'cba': 'A c m m'}, 'C m m m': {'abc': 'C m m m', 'acb': 'B m m m', 'bac': 'C m m m', 'bca': 'B m m m', 'cab': 'A m m m', 'cba': 'A m m m'}, 'F 2 2 2': {'abc': 'F 2 2 2', 'acb': 'F 2 2 2', 'bac': 'F 2 2 2', 'bca': 'F 2 2 2', 'cab': 'F 2 2 2', 'cba': 'F 2 2 2'}, 'F d d 2': {'abc': 'F d d 2', 'acb': 'F d 2 d', 'bac': 'F d d 2', 'bca': 'F d 2 d', 'cab': 'F 2 d d', 'cba': 'F 2 d d'}, 'F d d d': {'abc': 'F d d d', 'acb': 'F d d d', 'bac': 'F d d d', 'bca': 'F d d d', 'cab': 'F d d d', 'cba': 'F d d d'}, 'F m m 2': {'abc': 'F m m 2', 'acb': 'F m 2 m', 'bac': 'F m m 2', 'bca': 'F m 2 m', 'cab': 'F 2 m m', 'cba': 'F 2 m m'}, 'F m m m': {'abc': 'F m m m', 'acb': 'F m m m', 'bac': 'F m m m', 'bca': 'F m m m', 'cab': 'F m m m', 'cba': 'F m m m'}, 'I 2 2 2': {'abc': 'I 2 2 2', 'acb': 'I 2 2 2', 'bac': 'I 2 2 2', 'bca': 'I 2 2 2', 'cab': 'I 2 2 2', 'cba': 'I 2 2 2'}, 'I 21 21 21': {'abc': 'I 21 21 21', 'acb': 'I 21 21 21', 'bac': 'I 21 21 21', 'bca': 'I 21 21 21', 'cab': 'I 21 21 21', 'cba': 'I 21 21 21'}, 'I b a 2': {'abc': 'I b a 2', 'acb': 'I c 2 a', 'bac': 'I b a 2', 'bca': 'I c 2 a', 'cab': 'I 2 c b', 'cba': 'I 2 c b'}, 'I b a m': {'abc': 'I b a m', 'acb': 'I c m a', 'bac': 'I b a m', 'bca': 'I c m a', 'cab': 'I m c b', 'cba': 'I m c b'}, 'I b c a': {'abc': 'I b c a', 'acb': 'I c a b', 'bac': 'I c a b', 'bca': 'I b c a', 'cab': 'I b c a', 'cba': 'I c a b'}, 'I m a 2': {'abc': 'I m a 2', 'acb': 'I m 2 a', 'bac': 'I b m 2', 'bca': 'I c 2 m', 'cab': 'I 2 m b', 'cba': 'I 2 c m'}, 'I m m 2': {'abc': 'I m m 2', 'acb': 'I m 2 m', 'bac': 'I m m 2', 'bca': 'I m 2 m', 'cab': 'I 2 m m', 'cba': 'I 2 m m'}, 'I m m a': {'abc': 'I m m a', 'acb': 'I m a m', 'bac': 'I m m b', 'bca': 'I m c m', 'cab': 'I b m m', 'cba': 'I c m m'}, 'I m m m': {'abc': 'I m m m', 'acb': 'I m m m', 'bac': 'I m m m', 'bca': 'I m m m', 'cab': 'I m m m', 'cba': 'I m m m'}, 'P 2 2 2': {'abc': 'P 2 2 2', 'acb': 'P 2 2 2', 'bac': 'P 2 2 2', 'bca': 'P 2 2 2', 'cab': 'P 2 2 2', 'cba': 'P 2 2 2'}, 'P 2 2 21': {'abc': 'P 2 2 21', 'acb': 'P 2 21 2', 'bac': 'P 2 2 21', 'bca': 'P 2 21 2', 'cab': 'P 21 2 2', 'cba': 'P 21 2 2'}, 'P 21 21 2': {'abc': 'P 21 21 2', 'acb': 'P 21 2 21', 'bac': 'P 21 21 2', 'bca': 'P 21 2 21', 'cab': 'P 2 21 21', 'cba': 'P 2 21 21'}, 'P 21 21 21': {'abc': 'P 21 21 21', 'acb': 'P 21 21 21', 'bac': 'P 21 21 21', 'bca': 'P 21 21 21', 'cab': 'P 21 21 21', 'cba': 'P 21 21 21'}, 'P b a 2': {'abc': 'P b a 2', 'acb': 'P c 2 a', 'bac': 'P b a 2', 'bca': 'P c 2 a', 'cab': 'P 2 c b', 'cba': 'P 2 c b'}, 'P b a m': {'abc': 'P b a m', 'acb': 'P c m a', 'bac': 'P b a m', 'bca': 'P c m a', 'cab': 'P m c b', 'cba': 'P m c b'}, 'P b a n': {'abc': 'P b a n', 'acb': 'P c n a', 'bac': 'P b a n', 'bca': 'P c n a', 'cab': 'P n c b', 'cba': 'P n c b'}, 'P b c a': {'abc': 'P b c a', 'acb': 'P c a b', 'bac': 'P c a b', 'bca': 'P b c a', 'cab': 'P b c a', 'cba': 'P c a b'}, 'P b c m': {'abc': 'P b c m', 'acb': 'P c m b', 'bac': 'P c a m', 'bca': 'P b m a', 'cab': 'P m c a', 'cba': 'P m a b'}, 'P b c n': {'abc': 'P b c n', 'acb': 'P c n b', 'bac': 'P c a n', 'bca': 'P b n a', 'cab': 'P n c a', 'cba': 'P n a b'}, 'P c a 21': {'abc': 'P c a 21', 'acb': 'P b 21 a', 'bac': 'P b c 21', 'bca': 'P c 21 b', 'cab': 'P 21 a b', 'cba': 'P 21 c a'}, 'P c c 2': {'abc': 'P c c 2', 'acb': 'P b 2 b', 'bac': 'P c c 2', 'bca': 'P b 2 b', 'cab': 'P 2 a a', 'cba': 'P 2 a a'}, 'P c c a': {'abc': 'P c c a', 'acb': 'P b a b', 'bac': 'P c c b', 'bca': 'P b c b', 'cab': 'P b a a', 'cba': 'P c a a'}, 'P c c m': {'abc': 'P c c m', 'acb': 'P b m b', 'bac': 'P c c m', 'bca': 'P b m b', 'cab': 'P m a a', 'cba': 'P m a a'}, 'P c c n': {'abc': 'P c c n', 'acb': 'P b n b', 'bac': 'P c c n', 'bca': 'P b n b', 'cab': 'P n a a', 'cba': 'P n a a'}, 'P m a 2': {'abc': 'P m a 2', 'acb': 'P m 2 a', 'bac': 'P b m 2', 'bca': 'P c 2 m', 'cab': 'P 2 m b', 'cba': 'P 2 c m'}, 'P m c 21': {'abc': 'P m c 21', 'acb': 'P m 21 b', 'bac': 'P c m 21', 'bca': 'P b 21 m', 'cab': 'P 21 m a', 'cba': 'P 21 a m'}, 'P m m 2': {'abc': 'P m m 2', 'acb': 'P m 2 m', 'bac': 'P m m 2', 'bca': 'P m 2 m', 'cab': 'P 2 m m', 'cba': 'P 2 m m'}, 'P m m a': {'abc': 'P m m a', 'acb': 'P m a m', 'bac': 'P m m b', 'bca': 'P m c m', 'cab': 'P b m m', 'cba': 'P c m m'}, 'P m m m': {'abc': 'P m m m', 'acb': 'P m m m', 'bac': 'P m m m', 'bca': 'P m m m', 'cab': 'P m m m', 'cba': 'P m m m'}, 'P m m n': {'abc': 'P m m n', 'acb': 'P m n m', 'bac': 'P m m n', 'bca': 'P m n m', 'cab': 'P n m m', 'cba': 'P n m m'}, 'P m n 21': {'abc': 'P m n 21', 'acb': 'P m 21 n', 'bac': 'P n m 21', 'bca': 'P n 21 m', 'cab': 'P 21 m n', 'cba': 'P 21 n m'}, 'P m n a': {'abc': 'P m n a', 'acb': 'P m a n', 'bac': 'P n m b', 'bca': 'P n c m', 'cab': 'P b m n', 'cba': 'P c n m'}, 'P n a 21': {'abc': 'P n a 21', 'acb': 'P n 21 a', 'bac': 'P b n 21', 'bca': 'P c 21 n', 'cab': 'P 21 n b', 'cba': 'P 21 c n'}, 'P n c 2': {'abc': 'P n c 2', 'acb': 'P n 2 b', 'bac': 'P c n 2', 'bca': 'P b 2 n', 'cab': 'P 2 n a', 'cba': 'P 2 a n'}, 'P n m a': {'abc': 'P n m a', 'acb': 'P n a m', 'bac': 'P m n b', 'bca': 'P m c n', 'cab': 'P b n m', 'cba': 'P c m n'}, 'P n n 2': {'abc': 'P n n 2', 'acb': 'P n 2 n', 'bac': 'P n n 2', 'bca': 'P n 2 n', 'cab': 'P 2 n n', 'cba': 'P 2 n n'}, 'P n n a': {'abc': 'P n n a', 'acb': 'P n a n', 'bac': 'P n n b', 'bca': 'P n c n', 'cab': 'P b n n', 'cba': 'P c n n'}, 'P n n m': {'abc': 'P n n m', 'acb': 'P n m n', 'bac': 'P n n m', 'bca': 'P n m n', 'cab': 'P m n n', 'cba': 'P m n n'}, 'P n n n': {'abc': 'P n n n', 'acb': 'P n n n', 'bac': 'P n n n', 'bca': 'P n n n', 'cab': 'P n n n', 'cba': 'P n n n'}}
A dictionary of alternate settings for orthorhombic unit cells
GSASIIspc.checkHKLextc(HKL, SGData)[source]
Checks if reflection extinct - does not check centering
Parameters: HKL – [h,k,l] SGData – space group data obtained from SpcGroup True if extinct; False if allowed
GSASIIspc.checkMagextc(HKL, SGData)[source]
Checks if reflection magnetically extinct; does fullcheck (centering, too) uses algorthm from Gallego, et al., J. Appl. Cryst. 45, 1236-1247 (2012)
Parameters: HKL – [h,k,l] SGData – space group data obtained from SpcGroup; must have magnetic symmetry SpnFlp data True if magnetically extinct; False if allowed (to match GenHKLf)
GSASIIspc.fixMono(SpGrp)[source]
fixes b-unique monoclinics in e.g. P 1 2/1c 1 –> P 21/c
GSASIIspc.fullHM2shortHM(SpcGp)[source]
Accepts a full H-M space group symbol and returns a short H-M symbol that the space group interpreter can translate
GSASIIspc.selftestlist = [<function test0>, <function test1>, <function test2>, <function test3>]
Defines a list of self-tests
GSASIIspc.sgequiv_2002_orthorhombic = {'AE2A': 'A c 2 a', 'AE2M': 'A c 2 m', 'AEA2': 'A b a 2', 'AEAA': 'A b a a', 'AEAM': 'A c a m', 'AEM2': 'A b m 2', 'AEMA': 'A b m a', 'AEMM': 'A b m m', 'B2EB': 'B 2 c b', 'B2EM': 'B 2 c m', 'BBE2': 'B b a 2', 'BBEB': 'B b c b', 'BBEM': 'B b c m', 'BME2': 'B m a 2', 'BMEB': 'B m a b', 'BMEM': 'B m c m', 'C2CE': 'C 2 c b', 'C2ME': 'C 2 m b', 'CC2E': 'C c 2 a', 'CCCE': 'C c c a', 'CCME': 'C c m b', 'CM2E': 'C m 2 a', 'CMCE': 'C m c a', 'CMME': 'C m m a'}
A dictionary of orthorhombic space groups that were renamed in the 2002 Volume A, along with the pre-2002 name. The e designates a double glide-plane
GSASIIspc.spg2origins = {'A b a a': [-0.25, 0, -0.25], 'A c a a': [-0.25, -0.25, 0], 'B b a b': [0, -0.25, -0.25], 'B b c b': [-0.25, -0.25, 0], 'C c c a': [0, -0.25, -0.25], 'C c c b': [-0.25, 0, -0.25], 'F d - c': [-0.375, -0.375, -0.375], 'F d -3': [-0.125, -0.125, -0.125], 'F d -3 c': [-0.375, -0.375, -0.375], 'F d -3 m': [-0.125, -0.125, -0.125], 'F d 3': [-0.125, -0.125, -0.125], 'F d 3 m': [-0.125, -0.125, -0.125], 'F d d d': [-0.125, -0.125, -0.125], 'I 41/a': [0, -0.25, -0.125], 'I 41/a c d': [0, 0.25, -0.125], 'I 41/a m d': [0, 0.25, -0.125], 'P 4/n': [-0.25, -0.25, 0], 'P 4/n b m': [-0.25, -0.25, 0], 'P 4/n c c': [-0.25, -0.25, 0], 'P 4/n m m': [-0.25, -0.25, 0], 'P 4/n n c': [-0.25, -0.25, -0.25], 'P 42/n': [-0.25, -0.25, -0.25], 'P 42/n b c': [-0.25, -0.25, -0.25], 'P 42/n c m': [-0.25, 0.25, -0.25], 'P 42/n m c': [-0.25, 0.25, -0.25], 'P 42/n n m': [-0.25, 0.25, -0.25], 'P b a n': [-0.25, -0.25, 0], 'P c n a': [-0.25, 0, -0.25], 'P m m n': [-0.25, -0.25, 0], 'P m n m': [-0.25, 0, -0.25], 'P n -3 m': [-0.25, -0.25, -0.25], 'P n -3 n': [-0.25, -0.25, -0.25], 'P n 3 m': [-0.25, -0.25, -0.25], 'P n 3 n': [-0.25, -0.25, -0.25], 'P n c b': [0, -0.25, -0.25], 'P n m m': [0, -0.25, -0.25], 'P n n n': [-0.25, -0.25, -0.25], 'p n -3': [-0.25, -0.25, -0.25], 'p n 3': [-0.25, -0.25, -0.25]}
A dictionary of all spacegroups that have 2nd settings; the value is the 1st –> 2nd setting transformation vector as X(2nd) = X(1st)-V, nonstandard ones are included.
GSASIIspc.spgbyNum = [None, 'P 1', 'P -1', 'P 2', 'P 21', 'C 2', 'P m', 'P c', 'C m', 'C c', 'P 2/m', 'P 21/m', 'C 2/m', 'P 2/c', 'P 21/c', 'C 2/c', 'P 2 2 2', 'P 2 2 21', 'P 21 21 2', 'P 21 21 21', 'C 2 2 21', 'C 2 2 2', 'F 2 2 2', 'I 2 2 2', 'I 21 21 21', 'P m m 2', 'P m c 21', 'P c c 2', 'P m a 2', 'P c a 21', 'P n c 2', 'P m n 21', 'P b a 2', 'P n a 21', 'P n n 2', 'C m m 2', 'C m c 21', 'C c c 2', 'A m m 2', 'A b m 2', 'A m a 2', 'A b a 2', 'F m m 2', 'F d d 2', 'I m m 2', 'I b a 2', 'I m a 2', 'P m m m', 'P n n n', 'P c c m', 'P b a n', 'P m m a', 'P n n a', 'P m n a', 'P c c a', 'P b a m', 'P c c n', 'P b c m', 'P n n m', 'P m m n', 'P b c n', 'P b c a', 'P n m a', 'C m c m', 'C m c a', 'C m m m', 'C c c m', 'C m m a', 'C c c a', 'F m m m', 'F d d d', 'I m m m', 'I b a m', 'I b c a', 'I m m a', 'P 4', 'P 41', 'P 42', 'P 43', 'I 4', 'I 41', 'P -4', 'I -4', 'P 4/m', 'P 42/m', 'P 4/n', 'P 42/n', 'I 4/m', 'I 41/a', 'P 4 2 2', 'P 4 21 2', 'P 41 2 2', 'P 41 21 2', 'P 42 2 2', 'P 42 21 2', 'P 43 2 2', 'P 43 21 2', 'I 4 2 2', 'I 41 2 2', 'P 4 m m', 'P 4 b m', 'P 42 c m', 'P 42 n m', 'P 4 c c', 'P 4 n c', 'P 42 m c', 'P 42 b c', 'I 4 m m', 'I 4 c m', 'I 41 m d', 'I 41 c d', 'P -4 2 m', 'P -4 2 c', 'P -4 21 m', 'P -4 21 c', 'P -4 m 2', 'P -4 c 2', 'P -4 b 2', 'P -4 n 2', 'I -4 m 2', 'I -4 c 2', 'I -4 2 m', 'I -4 2 d', 'P 4/m m m', 'P 4/m c c', 'P 4/n b m', 'P 4/n n c', 'P 4/m b m', 'P 4/m n c', 'P 4/n m m', 'P 4/n c c', 'P 42/m m c', 'P 42/m c m', 'P 42/n b c', 'P 42/n n m', 'P 42/m b c', 'P 42/m n m', 'P 42/n m c', 'P 42/n c m', 'I 4/m m m', 'I 4/m c m', 'I 41/a m d', 'I 41/a c d', 'P 3', 'P 31', 'P 32', 'R 3', 'P -3', 'R -3', 'P 3 1 2', 'P 3 2 1', 'P 31 1 2', 'P 31 2 1', 'P 32 1 2', 'P 32 2 1', 'R 3 2', 'P 3 m 1', 'P 3 1 m', 'P 3 c 1', 'P 3 1 c', 'R 3 m', 'R 3 c', 'P -3 1 m', 'P -3 1 c', 'P -3 m 1', 'P -3 c 1', 'R -3 m', 'R -3 c', 'P 6', 'P 61', 'P 65', 'P 62', 'P 64', 'P 63', 'P -6', 'P 6/m', 'P 63/m', 'P 6 2 2', 'P 61 2 2', 'P 65 2 2', 'P 62 2 2', 'P 64 2 2', 'P 63 2 2', 'P 6 m m', 'P 6 c c', 'P 63 c m', 'P 63 m c', 'P -6 m 2', 'P -6 c 2', 'P -6 2 m', 'P -6 2 c', 'P 6/m m m', 'P 6/m c c', 'P 63/m c m', 'P 63/m m c', 'P 2 3', 'F 2 3', 'I 2 3', 'P 21 3', 'I 21 3', 'P m 3', 'P n 3', 'F m -3', 'F d -3', 'I m -3', 'P a -3', 'I a -3', 'P 4 3 2', 'P 42 3 2', 'F 4 3 2', 'F 41 3 2', 'I 4 3 2', 'P 43 3 2', 'P 41 3 2', 'I 41 3 2', 'P -4 3 m', 'F -4 3 m', 'I -4 3 m', 'P -4 3 n', 'F -4 3 c', 'I -4 3 d', 'P m -3 m', 'P n -3 n', 'P m -3 n', 'P n -3 m', 'F m -3 m', 'F m -3 c', 'F d -3 m', 'F d -3 c', 'I m -3 m', 'I a -3 d']
Space groups indexed by number
GSASIIspc.spglist = {'A2/m': ('A 2', 'A m', 'A a', 'A n', 'A 2/m', 'A 2/a', 'A 2/n'), 'Ammm': ('A 21 2 2', 'A 2 2 2', 'A 2 m m', 'A 21 m a', 'A 21 a m', 'A 2 a a', 'A m 2 m', 'A m m 2', 'A b m 2', 'A c 2 m', 'A m a 2', 'A m 2 a', 'A b a 2', 'A c 2 a', 'A m m a', 'A m a m', 'A b m a', 'A c a m', 'A m m m', 'A m a a', 'A b m m', 'A c m m', 'A c a a', 'A b a a'), 'Bmmm': ('B 2 21 2', 'B 2 2 2', 'B m 2 m', 'B m 21 b', 'B b 21 m', 'B b 2 b', 'B m m 2', 'B 2 m m', 'B 2 c m', 'B m a 2', 'B 2 m b', 'B b m 2', 'B 2 c b', 'B b a 2', 'B b m m', 'B m m b', 'B b c m', 'B m a b', 'B m m m', 'B b m b', 'B m a m', 'B m c m', 'B b a b', 'B b c b'), 'C1': ('C 1', 'C -1'), 'C2/m': ('C 2', 'C m', 'C c', 'C n', 'C 2/m', 'C 2/c', 'C 2/n'), 'Cmmm': ('C 2 2 21', 'C 2 2 2', 'C m m 2', 'C m c 21', 'C c m 21', 'C c c 2', 'C m 2 m', 'C 2 m m', 'C m 2 a', 'C 2 m b', 'C c 2 m', 'C 2 c m', 'C c 2 a', 'C 2 c b', 'C m c m', 'C c m m', 'C m c a', 'C c m b', 'C m m m', 'C c c m', 'C m m a', 'C m m b', 'C c c a', 'C c c b'), 'Fm3m': ('F 2 3', 'F m 3', 'F m -3', 'F d 3', 'F d -3', 'F 4 3 2', 'F 41 3 2', 'F -4 3 m', 'F -4 3 c', 'F m 3 m', 'F m -3 m', 'F m 3 c', 'F m -3 c', 'F d 3 m', 'F d -3 m', 'F d 3 c', 'F d -3 c'), 'Fmmm': ('F 2 2 2', 'F m m m', 'F d d d', 'F m m 2', 'F m 2 m', 'F 2 m m', 'F d d 2', 'F d 2 d', 'F 2 d d'), 'I2/m': ('I 2', 'I m', 'I a', 'I n', 'I c', 'I 2/m', 'I 2/a', 'I 2/c', 'I 2/n'), 'I4/mmm': ('I 4', 'I 41', 'I -4', 'I 4/m', 'I 41/a', 'I 4 2 2', 'I 41 2 2', 'I 4 m m', 'I 4 c m', 'I 41 m d', 'I 41 c d', 'I -4 m 2', 'I -4 c 2', 'I -4 2 m', 'I -4 2 d', 'I 4/m m m', 'I 4/m c m', 'I 41/a m d', 'I 41/a c d'), 'Im3m': ('I 2 3', 'I 21 3', 'I m 3', 'I m -3', 'I a 3', 'I a -3', 'I 4 3 2', 'I 41 3 2', 'I -4 3 m', 'I -4 3 d', 'I m -3 m', 'I m 3 m', 'I a 3 d', 'I a -3 d', 'I n 3 n', 'I n -3 n'), 'Immm': ('I 2 2 2', 'I 21 21 21', 'I m m 2', 'I m 2 m', 'I 2 m m', 'I b a 2', 'I 2 c b', 'I c 2 a', 'I m a 2', 'I 2 m b', 'I c 2 m', 'I m 2 a', 'I b m 2', 'I 2 c m', 'I m m m', 'I b a m', 'I m c b', 'I c m a', 'I b c a', 'I c a b', 'I m m a', 'I b m m ', 'I m c m', 'I m a m', 'I m m b', 'I c m m'), 'P1': ('P 1', 'P -1'), 'P2/m': ('P 2', 'P 21', 'P m', 'P a', 'P c', 'P n', 'P 2/m', 'P 21/m', 'P 2/c', 'P 2/a', 'P 2/n', 'P 21/c', 'P 21/a', 'P 21/n'), 'P4/mmm': ('P 4', 'P 41', 'P 42', 'P 43', 'P -4', 'P 4/m', 'P 42/m', 'P 4/n', 'P 42/n', 'P 4 2 2', 'P 4 21 2', 'P 41 2 2', 'P 41 21 2', 'P 42 2 2', 'P 42 21 2', 'P 43 2 2', 'P 43 21 2', 'P 4 m m', 'P 4 b m', 'P 42 c m', 'P 42 n m', 'P 4 c c', 'P 4 n c', 'P 42 m c', 'P 42 b c', 'P -4 2 m', 'P -4 2 c', 'P -4 21 m', 'P -4 21 c', 'P -4 m 2', 'P -4 c 2', 'P -4 b 2', 'P -4 n 2', 'P 4/m m m', 'P 4/m c c', 'P 4/n b m', 'P 4/n n c', 'P 4/m b m', 'P 4/m n c', 'P 4/n m m', 'P 4/n c c', 'P 42/m m c', 'P 42/m c m', 'P 42/n b c', 'P 42/n n m', 'P 42/m b c', 'P 42/m n m', 'P 42/n m c', 'P 42/n c m'), 'P6/mmm': ('P 3', 'P 31', 'P 32', 'P -3', 'P 3 1 2', 'P 3 2 1', 'P 31 1 2', 'P 31 2 1', 'P 32 1 2', 'P 32 2 1', 'P 3 m 1', 'P 3 1 m', 'P 3 c 1', 'P 3 1 c', 'P -3 1 m', 'P -3 1 c', 'P -3 m 1', 'P -3 c 1', 'P 6', 'P 61', 'P 65', 'P 62', 'P 64', 'P 63', 'P -6', 'P 6/m', 'P 63/m', 'P 6 2 2', 'P 61 2 2', 'P 65 2 2', 'P 62 2 2', 'P 64 2 2', 'P 63 2 2', 'P 6 m m', 'P 6 c c', 'P 63 c m', 'P 63 m c', 'P -6 m 2', 'P -6 c 2', 'P -6 2 m', 'P -6 2 c', 'P 6/m m m', 'P 6/m c c', 'P 63/m c m', 'P 63/m m c'), 'Pm3m': ('P 2 3', 'P 21 3', 'P m 3', 'P m -3', 'P n 3', 'P n -3', 'P a 3', 'P a -3', 'P 4 3 2', 'P 42 3 2', 'P 43 3 2', 'P 41 3 2', 'P -4 3 m', 'P -4 3 n', 'P m 3 m', 'P m -3 m', 'P n 3 n', 'P n -3 n', 'P m 3 n', 'P m -3 n', 'P n 3 m', 'P n -3 m'), 'Pmmm': ('P 2 2 2', 'P 2 2 21', 'P 21 2 2', 'P 2 21 2', 'P 21 21 2', 'P 2 21 21', 'P 21 2 21', 'P 21 21 21', 'P m m 2', 'P 2 m m', 'P m 2 m', 'P m c 21', 'P 21 m a', 'P b 21 m', 'P m 21 b', 'P c m 21', 'P 21 a m', 'P c c 2', 'P 2 a a', 'P b 2 b', 'P m a 2', 'P 2 m b', 'P c 2 m', 'P m 2 a', 'P b m 2', 'P 2 c m', 'P c a 21', 'P 21 a b', 'P c 21 b', 'P b 21 a', 'P b c 21', 'P 21 c a', 'P n c 2', 'P 2 n a', 'P b 2 n', 'P n 2 b', 'P c n 2', 'P 2 a n', 'P m n 21', 'P 21 m n', 'P n 21 m', 'P m 21 n', 'P n m 21', 'P 21 n m', 'P b a 2', 'P 2 c b', 'P c 2 a', 'P n a 21', 'P 21 n b', 'P c 21 n', 'P n 21 a', 'P b n 21', 'P 21 c n', 'P n n 2', 'P 2 n n', 'P n 2 n', 'P m m m', 'P n n n', 'P c c m', 'P m a a', 'P b m b', 'P b a n', 'P n c b', 'P c n a', 'P m m a', 'P b m m', 'P m c m', 'P m a m', 'P m m b', 'P c m m', 'P n n a', 'P b n n', 'P n c n', 'P n a n', 'P n n b', 'P c n n', 'P m n a', 'P b m n', 'P n c m', 'P m a n', 'P n m b', 'P c n m', 'P c c a', 'P b a a', 'P b c b', 'P b a b', 'P c c b', 'P c a a', 'P b a m', 'P m c b', 'P c m a', 'P c c n', 'P n a a', 'P b n b', 'P b c m', 'P m c a', 'P b m a', 'P c m b', 'P c a m', 'P m a b', 'P n n m', 'P m n n', 'P n m n', 'P m m n', 'P n m m', 'P m n m', 'P b c n', 'P n c a', 'P b n a', 'P c n b', 'P c a n', 'P n a b', 'P b c a', 'P c a b', 'P n m a', 'P b n m', 'P m c n', 'P n a m', 'P m n b', 'P c m n'), 'R3-H': ('R 3', 'R -3', 'R 3 2', 'R 3 m', 'R 3 c', 'R -3 m', 'R -3 c')}
A dictionary of space groups as ordered and named in the pre-2002 International Tables Volume A, except that spaces are used following the GSAS convention to separate the different crystallographic directions. Note that the symmetry codes here will recognize many non-standard space group symbols with different settings. They are ordered by Laue group
GSASIIspc.splitSSsym(SSymbol)[source]
Splits supersymmetry symbol into two lists of strings
GSASIIspc.test0()[source]
self-test #0: exercise MoveToUnitCell
GSASIIspc.test1()[source]
self-test #1: SpcGroup against previous results
GSASIIspc.test2()[source]
self-test #2: SpcGroup against cctbx (sgtbx) computations
GSASIIspc.test3()[source]
self-test #3: exercise SytSym (includes GetOprPtrName, GenAtom, GetKNsym) for selected space groups against info in IT Volume A
## 4.7. GSASIIdata: Data for computations¶
At present this module defines one dict, ramachandranDist, which contains arrays for All and specific amino acids.
## 4.8. GSASIIfiles: data (non-GUI) I/O routines¶
Module with miscellaneous routines for input and output from files.
This module should not contain any references to wxPython so that it can be imported for scriptable use or potentially on clients where wx is not installed.
Future refactoring: This module and GSASIIIO.py needs some work to move non-wx routines here. It may will likely make sense to rename the module(s) at that point.
GSASIIfiles.G2Print(*args, **kwargs)[source]
Print with filtering based level of output (see G2SetPrintLevel()). Use G2Print() as replacement for print().
Parameters: mode (str) – if specified, this should contain the mode for printing (‘error’, ‘warn’ or anything else). If not specified, the first argument of the print command (args[0]) should contain the string ‘error’ for error messages and ‘warn’ for warning messages (capitalization and additional letters ignored.)
GSASIIfiles.G2SetPrintLevel(level)[source]
Set the level of output from calls to G2Print(), which should be used in place of print() within GSASII. Settings for the mode are ‘all’, ‘warn’, ‘error’ or ‘none’
Parameters: level (str) – a string used to set the print level, which may be ‘all’, ‘warn’, ‘error’ or ‘none’. Note that capitalization and extra letters in level are ignored, so ‘Warn’, ‘warnings’, etc. will all set the mode to ‘warn’
GSASIIfiles.G2printLevel = 'all'
This defines the level of output from calls to G2Print(), which should be used in place of print() within this module. Settings for this are ‘all’, ‘warn’, ‘error’ or ‘none’. Also see: G2Print() and G2SetPrintLevel().
GSASIIfiles.GetColumnMetadata(reader)[source]
Add metadata to an image from a column-type metadata file using readColMetadata()
GSASIIfiles.LoadControls(Slines, data)[source]
Read values from a .imctrl (Image Controls) file
GSASIIfiles.LoadExportRoutines(parent, traceback=False)[source]
Routine to locate GSASII exporters
GSASIIfiles.LoadImportRoutines(prefix, errprefix=None, traceback=False)[source]
Routine to locate GSASII importers matching a prefix string
GSASIIfiles.PDFWrite(PDFentry, fileroot, PDFsaves, PDFControls, Inst={}, Limits=[])[source]
Write PDF-related data (G(r), S(Q),…) into files, as selected.
Parameters: PDFentry (str) – name of the PDF entry in the tree. This is used for comments in the file specifying where it came from; it can be arbitrary fileroot (str) – name of file(s) to be written. The extension will be ignored. PDFsaves (list) – flags that determine what type of file will be written: PDFsaves[0], if True writes a I(Q) file with a .iq extension PDFsaves[1], if True writes a S(Q) file with a .sq extension PDFsaves[2], if True writes a F(Q) file with a .fq extension PDFsaves[3], if True writes a G(r) file with a .gr extension PDFsaves[4], if True writes G(r) in a pdfGUI input file with a .gr extension. Note that if PDFsaves[3] and PDFsaves[4] are both True, the pdfGUI overwrites the G(r) file. PDFsaves[5], if True writes F(Q) & g(R) with .fq & .gr extensions overwrites these if selected by option 2, 3 or 4 PDFControls (dict) – The PDF parameters and computed results Inst (dict) – Instrument parameters from the PDWR entry used to compute the PDF. Needed only when PDFsaves[4] is True. Limits (list) – Computation limits from the PDWR entry used to compute the PDF. Needed only when PDFsaves[4] is True.
GSASIIfiles.ReadPowderInstprm(instLines, bank, databanks, rd)[source]
Read lines from a GSAS-II (new) instrument parameter file similar to G2pwdGUI.OnLoad If instprm file has multiple banks each with header #Bank n: …, this finds matching bank no. to load - problem with nonmatches?
Note that this routine performs a similar role to GSASIIdataGUI.GSASII.ReadPowderInstprm(), but that will call a GUI routine for selection when needed. This routine will raise exceptions on errors and will select the first bank when a choice might be appropriate. TODO: refactor to combine the two routines.
Parameters: instLines (list) – strings from GSAS-II parameter file; can be concatenated with ‘;’ bank (int) – bank number to check when instprm file has ‘#BANK n:…’ strings when bank = n then use parameters; otherwise skip that set. Ignored if BANK n: not present. NB: this kind of instprm file made by a Save all profile command in Instrument Par ameters Inst instrument parameter dict if OK, or str: Error message if failed
(transliterated from GSASIIdataGUI.py:1235 (rev 3008), function of the same name)
GSASIIfiles.RereadImageData(ImageReaderlist, imagefile, ImageTag=None, FormatName='')[source]
Read a single image with an image importer. This is called to reread an image after it has already been imported, so it is not necessary to reload metadata.
Based on GetImageData.GetImageData() which this can replace where imageOnly=True
Parameters: ImageReaderlist (list) – list of Reader objects for images imagefile (str) – name of image file ImageTag (int/str) – specifies a particular image to be read from a file. First image is read if None (default). formatName (str) – the image reader formatName an image as a numpy array
GSASIIfiles.SetPowderInstParms(Iparm, rd)[source]
extracts values from instrument parameters in rd.instdict or in array Iparm. Create and return the contents of the instrument parameter tree entry.
GSASIIfiles.WriteControls(filename, data)[source]
Write current values to a .imctrl (Image Controls) file
GSASIIfiles.evalColMetadataDicts(items, labels, lbldict, keyCols, keyExp, ShowError=False)[source]
Evaluate the metadata for a line in the .par file
GSASIIfiles.find(name, path)[source]
find 1st occurance of file in path
GSASIIfiles.readColMetadata(imagefile)[source]
Reads image metadata from a column-oriented metadata table (1-ID style .par file). Called by GetColumnMetadata()
The .par file has any number of columns separated by spaces. The directory for the file must be specified in Config variable config_example.Column_Metadata_directory. As an index to the .par file a second “label file” must be specified with the same file root name as the .par file but the extension must be .XXX_lbls (where .XXX is the extension of the image) or if that is not present extension .lbls.
Parameters: imagefile (str) – the full name of the image file (with extension, directory optional) a dict with parameter values. Named parameters will have the type based on the specified Python function, named columns will be character strings
The contents of the label file will look like this:
# define keywords
filename:lambda x,y: "{}_{:0>6}".format(x,y)|33,34
distance: float | 75
wavelength:lambda keV: 12.398425/float(keV)|9
pixelSize:lambda x: [74.8, 74.8]|0
ISOlikeDate: lambda dow,m,d,t,y:"{}-{}-{}T{} ({})".format(y,m,d,t,dow)|0,1,2,3,4
Temperature: float|53
FreePrm2: int | 34 | Free Parm2 Label
# define other variables
0:day
1:month
2:date
3:time
4:year
7:I_ring
This file contains three types of lines in any order.
• Named parameters are evaluated with user-supplied Python code (see subsequent information). Specific named parameters are used to determine values that are used for image interpretation (see table, below). Any others are copied to the Comments subsection of the Image tree item.
• Column labels are defined with a column number (integer) followed by a colon (:) and a label to be assigned to that column. All labeled columns are copied to the Image’s Comments subsection.
• Comments are any line that does not contain a colon.
Note that columns are numbered starting at zero.
Any named parameter may be defined provided it is not a valid integer, but the named parameters in the table have special meanings, as descibed. The parameter name is followed by a colon. After the colon, specify Python code that defines or specifies a function that will be called to generate a value for that parameter.
Note that several keywords, if defined in the Comments, will be found and placed in the appropriate section of the powder histogram(s)’s Sample Parameters after an integration: Temperature, Pressure, Time, FreePrm1, FreePrm2, FreePrm3, Omega, Chi, and Phi.
After the Python code, supply a vertical bar (|) and then a list of one more more columns that will be supplied as arguments to that function.
Note that the labels for the three FreePrm items can be changed by including that label as a third item with an additional vertical bar. Labels will be ignored for any other named parameters.
The examples above are discussed here:
filename:lambda x,y: "{}_{:0>6}".format(x,y)|33,34
Here the function to be used is defined with a lambda statement:
lambda x,y: "{}_{:0>6}".format(x,y)
This function will use the format function to create a file name from the contents of columns 33 and 34. The first parameter (x, col. 33) is inserted directly into the file name, followed by a underscore (_), followed by the second parameter (y, col. 34), which will be left-padded with zeros to six characters (format directive :0>6).
When there will be more than one image generated per line in the .par file, an alternate way to generate list of file names takes into account the number of images generated:
lambda x,y,z: ["{}_{:0>6}".format(x,int(y)+i) for i in range(int(z))]
Here a third parameter is used to specify the number of images generated, where the image number is incremented for each image.
distance: float | 75
Here the contents of column 75 will be converted to a floating point number by calling float on it. Note that the spaces here are ignored.
wavelength:lambda keV: 12.398425/float(keV)|9
Here we define an algebraic expression to convert an energy in keV to a wavelength and pass the contents of column 9 as that input energy
pixelSize:lambda x: [74.8, 74.8]|0
In this case the pixel size is a constant (a list of two numbers). The first column is passed as an argument as at least one argument is required, but that value is not used in the expression.
ISOlikeDate: lambda dow,m,d,t,y:"{}-{}-{}T{} ({})".format(y,m,d,t,dow)|0,1,2,3,4
This example defines a parameter that takes items in the first five columns and formats them in a different way. This parameter is not one of the pre-defined parameter names below. Some external code could be used to change the month string (argument m) to a integer from 1 to 12.
FreePrm2: int | 34 | Free Parm2 Label
In this example, the contents of column 34 will be converted to an integer and placed as the second free-named parameter in the Sample Parameters after an integration. The label for this parameter will be changed to “Free Parm2 Label”.
Pre-defined parameter names
keyword required type Description
filename yes str or list generates the file name prefix for the matching image file (MyImage001 for file /tmp/MyImage001.tif) or a list of file names.
polarization no float generates the polarization expected based on the monochromator angle, defaults to 0.99.
center no list of 2 floats generates the approximate beam center on the detector in mm, such as [204.8, 204.8].
distance yes float generates the distance from the sample to the detector in mm
pixelSize no list of 2 floats generates the size of the pixels in microns such as [200.0, 200.0].
wavelength yes float generates the wavelength in Angstroms
GSASIIfiles.readColMetadataLabels(lblFil)[source]
GSASIIfiles.readMasks(filename, masks, ignoreThreshold)[source]
GSASIIfiles.sfloat(S)[source]
Convert a string to float. An empty field or a unconvertable value is treated as zero
## 4.9. GSASIImpsubs: routines used in multiprocessing¶
The routines here are called either directly when GSAS-II is used without multiprocessing or in separate cores when multiprocessing is used.
These routines are designed to be used in one of two ways:
• when multiprocessing is enabled (see global variable useMP) the computational routines are called in separate Python interpreter that is created and then deleted after use.
• when useMP is False, these routines are called directly from the main “thread”.
Note that GSASIImpsubs.InitMP() should be called before any of the other routines in this module are used.
GSASIImpsubs.ComputePwdrProfCW(profList)[source]
Compute the peaks profile for a set of CW peaks and add into the yc array
GSASIImpsubs.ComputePwdrProfED(profList)[source]
Compute the peaks profile for a set of TOF peaks and add into the yc array
GSASIImpsubs.ComputePwdrProfPink(profList)[source]
Compute the peaks profile for a set of TOF peaks and add into the yc array
GSASIImpsubs.ComputePwdrProfTOF(profList)[source]
Compute the peaks profile for a set of TOF peaks and add into the yc array
GSASIImpsubs.InitFobsSqGlobals(x1, ratio1, shl1, xB1, xF1, im1, lamRatio1, kRatio1, xMask1, Ka21)[source]
Initialize for the computation of Fobs Squared for powder histograms. Puts lots of junk into the global namespace in this module.
GSASIImpsubs.InitMP(allowMP=True)[source]
Called to initialize use of Multiprocessing
GSASIImpsubs.InitPwdrProfGlobals(im1, shl1, x1)[source]
Initialize for the computation of Fobs Squared for powder histograms. Puts lots of junk into the global namespace in this module.
GSASIImpsubs.ResetMP()[source]
Call after changing Config var ‘Multiprocessing_cores’ to force a resetting of the useMP from the parameter.
## 4.10. Module nistlat: NIST*LATTICE cell computations¶
This implements an interface to the NIST*LATTICE code using the Spring 1991 program version. NIST*LATTICE, “A Program to Analyze Lattice Relationships” was created by Vicky Lynn Karen and Alan D. Mighell (National Institute of Standards and Technology, Materials Science and Engineering Laboratory, Gaithersburg, Maryland 20899.) Minor code modifications made to provide more significant digits for cell reduction matrix terms.
Please cite V. L. Karen and A. D. Mighell, NIST Technical Note 1290 (1991), https://nvlpubs.nist.gov/nistpubs/Legacy/TN/nbstechnicalnote1290.pdf; and V. L. Karen & A. D. Mighell, U.S. Patent 5,235,523, https://patents.google.com/patent/US5235523A/en?oq=5235523 if this module is used.
This will be deployed in GSAS-II after a release of updated binary images.
nistlat.CellSymSearch(cellin, center, tolerance=[0.2, 0.2, 0.2, 1, 1, 1], mode=0, deltaV=2, output=None)[source]
Search for a higher symmetry lattice related to an input unit cell, and optionally to the supercells and/or subcells with a specified volume ratio to the input cell.
Parameters: cellin (list) – six lattice constants as float values center (str) – cell centering code; one of P/A/B/C/F/I/R Note that ‘R’ is used for rhombohedral lattices in either hexagonal or rhombohedral (primitive) cells tolerance (list) – comparison tolerances for a, b, c, alpha, beta & gamma (defaults to [0.2,0.2,0.2,1.,1.,1.] mode (int) – 0: use only input cell, 1: generate supercells, 2: generate subcells 3: generate sub- and supercells deltaV (int) – volume ratios for sub/supercells if mode != 0 as ratio of original cell to smallest subcell or largest supercell to original cell. Ignored if mode=0. Otherwise should be 2, 3, 4 or 5 output (str) – name of file to write the NIST*LATTICE output. Default is None, which does not produce a file. a list of processed cells (only one entry in list when mode=0) where for each cell the the following items are included: conventional input cell; reduced input cell; symmetry-generated conventional cell; symmetry-generated reduced cell; matrix to convert sym-generated output cell to input conventional cell
nistlat.CompareCell(cell1, center1, cell2, center2, tolerance=[0.2, 0.2, 0.2, 1, 1, 1], mode='I', vrange=8, output=None)[source]
Search for matrices that relate two unit cells
Parameters: cell1 (list) – six lattice constants as float values for 1st cell center1 (str) – cell centering code for 1st cell; one of P/A/B/C/F/I/R Note that ‘R’ is used for rhombohedral lattices in either hexagonal or rhombohedral (primitive) cells cell2 (list) – six lattice constants as float values for 2nd cell center2 (str) – cell centering code for 2nd cell (see center1) tolerance (list) – comparison tolerances for a, b, c, alpha, beta & gamma (defaults to [0.2,0.2,0.2,1.,1.,1.] mode (str) – search mode, which should be either ‘I’ or ‘F’ ‘I’ provides searching with integral matrices or ‘F’ provides searching with integral and fractional matrices vrange (int) – maximum matrix term range. Must be 1 <= vrange <= 10 for mode=’F’ or Must be 1 <= vrange <= 40 for mode=’I’ output (str) – name of file to write the NIST*LATTICE output. Default is None, which does not produce a file. A list of matrices that match cell1 to cell2 where each entry contains (det, im, m, tol, one2two, two2one) where: det is the determinant, giving the volume ratio between cells im relates the reduced cell for cell1 to the reduced cell for cell2 m relates the reduced cell for cell2 to the reduced cell for cell1 tol shows the quality of agreement, as six differences between the two reduced cells one2two: a numpy matrix that transforms cell1 to cell2 two2one: a numpy matrix that transforms cell2 to cell1
nistlat.ConvCell(redcell)[source]
Converts a reduced cell to a conventional cell
Parameters: redcell (list) – unit cell parameters as 3 cell lengths and 3 angles (in degrees) tuple (cell,center,setting,mat) where: cell: has the six cell dimensions for the conventional cell; center: is P/A/B/C/F/I/R; setting: is ‘ ‘ except for rhombohedral symmetry (center=R), where it will always be H (for hexagonal cell choice); mat: is the matrix that gives the conventional cell when the reduced cell is multiplied by mat.
nistlat.ReduceCell(center, cellin, mode=0, deltaV=0, output=None)[source]
Compute reduced cell(s) with NIST*LATTICE
Parameters: center (str) – cell centering code; one of P/A/B/C/F/I/R Note that ‘R’ is used for rhombohedral lattices in either hexagonal or rhombohedral (primitive) cells cellin (list) – six lattice constants as float values mode (int) – 0: reduction, 1: generate supercells, 2: generate subcells 3: generate sub- and supercells deltaV (int) – volume ratios for sub/supercells if mode != 0 as ratio of original cell to smallest subcell or largest supercell to original cell. Ignored if mode=0. Otherwise should be 2, 3, 4 or 5 output (str) – name of file to write the NIST*LATTICE output. Default is None, which does not produce a file. a dict with two items, ‘input’ and ‘output’. The value for ‘input’ is the input cell as (cell,center,setting). The value for ‘output’ is a list of reduced cells of form (d,cell,vol,mat,center,setting). In these: cell: a list with the six cell dimensions; center: is as above (always ‘P’ on output); setting: is ‘ ‘ except for rhombohedral symmetry where it may be R or H for the cell type; d: is the volume ratio for new cell over input cell; vol: is volume of output cell mat: is the matrix that gives the output cell when the input cell is multiplied by mat.
nistlat.showCell(cell, center='P', setting=' ', *ignored)[source]
show unit cell input or output nicely formatted.
Parameters: cell (list) – six lattice constants as float values; a 7th volume value is ignored if present. center (str) – cell centering code; one of P/A/B/C/F/I/R Note that ‘R’ is used for rhombohedral lattices in either rhombohedral (primitive) or hexagonal cells. setting (str) – is ‘ ‘ except for rhombohedral symmetry where it will be R or H for the cell type. a formatted string
nistlat.uniqCells(cellList)[source]
remove duplicated cells from a cell output list from ReduceCell()
Parameters: cellList (list) – A list of reduced cells where each entry represents a reduced cell as (_,cell,_,_,center,…) where cell has six lattice constants and center is the cell centering code (P/A/B/C/F/I/R). a list as above, but where each unique cell is listed only once
## 4.11. ElementTable: Periodic Table Data¶
Element table data for building periodic table with valences & JMOL colors. Need these in case we go back to this periodic table coloring scheme.
Defines list ElTable which contains all defined oxidation states for each element, the location in the table, an element name, a color, a size and a second color.
## 4.12. FormFactors: Scattering Data¶
Contains atomic scattering factors from “New Analytical Scattering Factor Functions for Free Atoms and Ions for Free Atoms and Ions”, D. Waasmaier & A. Kirfel, Acta Cryst. (1995). A51, 416-413.
Also, tabulated coefficients for calculation of Compton Cross Section as a function of sin(theta)/lambda from “Analytic Approximations to Incoherently Scattered X-Ray Intensities”, H. H. M. Balyuzi, Acta Cryst. (1975). A31, 600.
## 4.13. ImageCalibrants: Calibration Standards¶
GSASII powder calibrants in dictionary ImageCalibrants.Calibrants containing substances commonly used for powder calibrations for image data.
Each entry in ImageCalibrants consists of:
'key':([Bravais num,],[space group,],[(a,b,c,alpha,beta,gamma),],no. lines skipped,(dmin,pixLimit,cutOff),(absent list))
* See below for Bravais num assignments.
* The space group may be an empty string.
* The absent list is optional; it gives indices of lines that have no intensity despite being allowed - see the Si example below; counting begins at zero
As an example:
'LaB6 SRM660a':([2,],['',][(4.1569162,4.1569162,4.1569162,90,90,90),],0,(1.0,10,10.)),
For calibrants that are mixtures, the “Bravais num” and “(a,b,…)” values are repeated, as in this case:
'LaB6 & CeO2':([2,0],['',''] [(4.1569,4.1569,4.1569,90,90,90),(5.4117,5.4117,5.4117,90,90,90)], 0, (1.0,2,1.)),
Note that Si has reflections (the 4th, 11th,…) that are not extinct by symmetry but still have zero intensity. These are supplied in the final list:
'Si':([0,],['F d 3 m'],[(5.4311946,5.4311946,5.4311946,90,90,90),],0,(1.,10,10.),(3,10,13,20,23,26,33,35,40,43)),
Note, the Bravais numbers are:
• 0 F cubic
• 1 I cubic
• 2 P cubic
• 3 R hexagonal (trigonal not rhombohedral)
• 4 P hexagonal
• 5 I tetragonal
• 6 P tetragonal
• 7 F orthorhombic
• 8 I orthorhombic
• 9 C orthorhombic
• 10 P orthorhombic
• 11 C monoclinic
• 12 P monoclinic
• 13 P triclinic
### 4.13.1. User-Defined Calibrants¶
To expand this list with locally needed additions, do not modify this ImageCalibrants.py file, because you may lose these changes during a software update. Instead duplicate the format of this file in a file named UserCalibrants.py and there define the material(s) you want:
Calibrants={
'LaB6 skip 2 lines':([2,],['',],[(4.1569162,4.1569162,4.1569162,90,90,90),],2,(1.0,10,10),()),
}
New key values will be added to the list of options. If a key is duplicated, the information in UserCalibrants.py will override the entry in this (the ImageCalibrants.py file).
## 4.14. atmdata: Table of atomic data¶
The entries here are:
XrayFF: a dict of form factor coefficients
AtmBlens: atom masses & neutron scattering length (b,b’), sig(incoh) @ 1A
MagFF: neutron magnetic form factor coeff: M for j<0> & N for j<2>
Sources:
Exponential scattering factor curve coeficients, Cromer and Waber(1971) Int. Tables Vol. IV. Delta f’ and delta f” terms calcd via D.T. Cromer & D.A. Liberman (1981), Acta Cryst. A37, 267-268. Atomic weights from CRC 56th Edition
Electron scattering factor curve coefficients from International Tables for Crystallography, Vol. C, Ch 4. Sect. 4.3.2.
Neutron scattering lengths & abs. cross sections from H. Rauch & W. Waschowski, Neutron Data Booklet, 2003. X-ray <j0> & <j2> coeff. from Intl. Tables for Cryst, Vol. C 5-d <j0> & <j2> from Kobayashi K, Nagao T, Ito M. Acta Crystallogr A67, 473-480 (2011)
Neutron anomalous coeff (LS) from fitting Lynn & Seeger, At. Data & Nuc. Data Tables, 44, 191-207(1990)
O2- x-ray scattering factor from Tokonami (1965) Acta Cryst 19, 486
At wts from 14th ed Nuclides & Isotopes, 1989 GE Co.
## 4.15. defaultIparms: Table of instrument parameters¶
Defines some default instrument parameters. Format for each is a list of strings finished with a ‘ ‘. Begin with ‘#GSAS-II…’ as the reader routine checks this. Each line can be comprised of a block of ‘;’ delimited name:value pairs. All instrument parameters must be included; even those = 0. Use a GSAS-II instprm file as a source for the entries.
For a new entry:
Append a useful name to defaultIparms_lbl.
Append the list of lines to defaultIparms.
defaultIparm_lbl: defines a list of labels.
defaultIparms: defines a list of multiple strings with values for each set of defaults.
class ReadMarCCDFrame.marFrame(File, byteOrd='<', IFD={})[source]
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http://zinh.github.io/ruby/2018/04/29/ruby-hacking-day-1.html
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I’ve been wanting to take a look at Ruby’s core for sometime. I will try do do some coding with Ruby’s source from this week and write some blog posts along.
This week, I want to setup the development enviroment, I will test on both Mac and Linux(Ubuntu) to see if there is any difference.
## Compile ruby from source
First, pull the source from github(I will use 2.5.1 version)
mkdir workspace
cd workspace
git clone --depth 1 --branch v2_5_1 [email protected]:ruby/ruby.git ruby_source
cd ruby_source
On Mac, we will need autoconf, openssl(as the default tls library of Mac is not compatible with Ruby), and readline to compile Ruby from source.
brew install autoconf openssl readline
Run autoconf inside ruby_source directory
autoconf
mkdir build
cd build
../configure --prefix=$PWD/install --enable-shared --with-openssl-dir="$(brew --prefix openssl)"
--disable-libedit
make
make install
On Ubuntu, we will need to install the following libraries
apt-get install -y build-essentials libssl-dev libreadline-dev zlib1g-dev bison ruby
Funny thing is we will need a working Ruby in order to compile Ruby from source; therefore, the command above also installs ruby from apt. After that, we compile and install same as on Mac.
If there is no problem, we will have ruby binary installed to workspace/ruby/build/install directory.
## Miniruby
During compilation process, there is a mini version of Ruby called miniruby, this one will be use to compile the full version of Ruby. Because it’s a minified version, compiling of miniruby is much faster than the full version. We can use it to test our changes in Ruby’s source and have a faster feedback. In fact, Ruby the command make run is use for this purpose.
In order to invoke make run we need to create a test.rb file in ruby source folder, for example
cd ruby_source
echo "puts 'hello world'" > test.rb
cd build
make run
Another useful command is make runruby, this one also run test.rb but with full version of ruby.
So the workflow when making change Ruby would be like
1. Making some changes
2. Wring some code to test new feature in test.rb
3. Running it with make run
## Debugging using gdb(Linux only)
One of the important thing when working with C code is debugging(or any other language for that matter), on Linux it would be gdb. To debug using gdb we can use make gdb. This will invoke miniruby, run test.rb and exit(if there is no error). So for example
echo "put 'Hello world'" > test.rb
cd build
make gdb
## Debugging using lldb(Mac)
It is very troublesome to setup gdb on Mac, we can use lldb which is provided together with clang and llvm’s friends on Mac. Ruby also provide the command make lldb with same function as make gdb. It will stop right before execution of the script, we can inspect code, set breakpoint from there. For example
echo "put 'Hello world'" > test.rb
cd build
make lldb
So, that’s all for this time. Next week, I will try to create some simple method with Ruby and do some simple debug with gdb/lldb.
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https://planetmath.org/diagonal
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# diagonal
Let $P$ be a polygon or a polyhedron. Two vertices on $P$ are adjacent if the line segment joining them is an edge of $P$. A diagonal of $P$ is a line segment joining two non-adjacent vertices.
Below is a figure showing a hexagon and all its diagonals (in red) with $X$ as one of its endpoints.
Remarks.
• If $P$ is convex, then the relative interior of a diagonal lies in the relative interior of $P$. Below is a figure showing that a diagonal may partially lie outside of $P$.
\begin{pspicture}(-227.62204pt,0.0pt)(0.0pt,56.905502pt)\leavevmode% \ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces% \ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces% \ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces% \special{pst: \pst@dict\tx@STP\pst@newpath\psk@origin\psk@swapaxes\pst@code end }\ignorespaces\leavevmode\ignorespaces\ignorespaces\ignorespaces\ignorespaces% \special{pst: \pst@dict\tx@STP\pst@newpath\psk@origin\psk@swapaxes\pst@code end }\ignorespaces\end{pspicture}
• If a polygon $P$ has $n$ (distinct) vertices, then it has $\displaystyle{\frac{n(n-3)}{2}}$ diagonals.
Title diagonal Diagonal 2013-03-22 17:34:41 2013-03-22 17:34:41 CWoo (3771) CWoo (3771) 7 CWoo (3771) Definition msc 51N05 BasicPolygon Polyhedron adjacent vertices
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http://sumsar.net/blog/2014/03/a-hack-to-create-matrices-in-R-matlab-style/
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# A Hack to Create Matrices in R, Matlab style
The Matlab syntax for creating matrices is pretty and convenient. Here is a 2x3 matrix in Matlab syntax where , marks a new column and ; marks a new row:
Here is how to create the corresponding matrix in R:
Functional but not as pretty, plus the default is to specify the values column wise. A better solution is to use rbind:
Lately I’ve been reading up on the metaprogramming capabilities of R in Hadley Wickham’s great Advanced R programming (while it is freely available online, you can already pre-order the IRL version here). Using metaprogramming we can hack together a function that allow us to create matrices in a similar way as in Matlab. I’ll first show some examples of how the function works and after that I’ll show you the code. The function is called qm as in “quick matrix” where , is used to separate columns and | is used to separate rows:
Pretty cool, right? :)
Here is finally the full qm function. The trick is roughly to grab the arguments to qm as a list, split every argument with a | into two, and finally form the rows of the matrix by evaluating and concatenating the arguments between each |. (qm is not extensively tested so use it at your own risk and please tell me if you find any way to improve the code!)
While I’m not sure that qm is really a super useful function, I still think it is a nice example of what you can hack together using the metaprogramming facilities of R.
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https://tex.stackexchange.com/questions/32244/symbol-for-skeptical-consequence-that-matches-the-turnstile-package
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# Symbol for skeptical consequence that matches the turnstile package
This might be seen as a follow up to Symbol for skeptical consequence. From it I got answers so that I could write that B is a skeptical consequence of A such as
which Peter Grill's code produces. Now say that I use the turnstile package to typeset turnstiles which symbolizes logical consequence, that I prefer the turnstiles of the turnstile package to \vdash and \vDash, and that I in the same text want to speak both of logical and skeptical consequence. Then I face two problems:
1. The turnstiles of the turnstiles package don't match any of the symbols for skeptical consequence in the answers of Symbol for skeptical consequence because the turnstiles of the turnstile package are larger.
2. The turnstiles of the turnstile package is superior in how symbols are placed below the turnstile.
This can be illustrated by the following which symbolizes that B is a skeptical consequence of A in language L and that B is a logical consequence of A in language L:
What I would like is, ideally, an extension of the turnstile package to handle skeptical consequence so that I could produce turnstiles with a wavy horizontal that matches the (normal) turnstiles, both in terms of appearance and ability to have correctly placed symbols below and above, of the turnstile package. Also, in contrast to what the images shows, I'd like the wavy line to be such that it has the same thickness and edges as the vertical line.
The turnstile package provides
\turnstile[<size>]{<lvert>}{<horz>}{<below>}{<above>}{<rvert>}
where <horz> calls the macro
\makehor{<line type>}{<thickness>}{<length>}{<sep>}
to draw the horizontal line(s) of the turnstile. In the following code, I've redefined \makehor (and consequently also \turnstile) to take a first argument w (for wavy) which typesets the symbol $\sim$ as the "horizontal line". The adjustbox package provides some clipping and resizing.
\documentclass{article}
\usepackage{turnstile}% http://ctan.org/pkg/turnstile
\renewcommand{\makehor}[4]
{\ifthenelse{\equal{#1}{n}}{\hspace{#3}}{}
\ifthenelse{\equal{#1}{s}}{\rule[-0.5#2]{#3}{#2}}{}
\ifthenelse{\equal{#1}{d}}{\setlength{\lengthvar}{#2}
\rule[-\lengthvar]{#3}{#2}
\hspace{-#3}
\rule[0.5#4]{#3}{#2}}{}
\ifthenelse{\equal{#1}{t}}{\setlength{\lengthvar}{1.5#2}
\rule[-\lengthvar]{#3}{#2}
\hspace{-#3}
\rule[-0.5#2]{#3}{#2}
\hspace{-#3}
\setlength{\lengthvar}{0.5#2}
\rule[\lengthvar]{#3}{#2}}{}
\ifthenelse{\equal{#1}{w}}{% New wavy $\sim$ definition
\setbox0=\hbox{$\sim$}%
}
\begin{document}
$\renewcommand{\arraystretch}{2}% \begin{array}{ll} \textrm{Regular}\ \verb!s! & \textrm{Wavy}\ \verb!w! \\ \hline A\turnstile{s}{s}{}{}{n}B & A\turnstile{s}{w}{}{}{n}B \\ A\turnstile{s}{s}{L}{}{n}B & A\turnstile{s}{w}{L}{}{n}B \\ A\turnstile{s}{s}{}{D}{n}B & A\turnstile{s}{w}{}{D}{n}B \\ A\turnstile{s}{s}{L}{D}{n}B & A\turnstile{s}{w}{L}{D}{n}B \end{array}$
\end{document}
The main advantage of tapping into the existing command (or extending it) rather than writing one's own is that it is easier to use. Additionally, since \turnstile takes the upper/lower letters as arguments, it's easier to grab hold of them than (say) defining a new command that requires some interpretation of limit use, like \wavyturn_{L}^{D} (say). As such, the other features of \turnstile is adopted (like the \rule for the vertical line and the other spacing.
The above code currently only works for a single wavy line. However, if needed, it could be extended to work for more than one (like the original \turnstile..{d}... and \turnstile..{t}.. commands). For now, it works based on the MWE, but not work as expected with other variations (longer phrases and/or right vertical line). That may require more work, since I haven't tested it.
Edit: Admittedly my tikz-prowess requires a heavy boost of steroids. The following addition to the turnstile horizontal rule is provided by the symbol z. It draws a thin wavy line using a sine curve. I'm pretty sure the horizontal (\hspace) and vertical (\raisebox) adjustments can be done inside \tikz, so suggestions are welcome and encouraged. The same goes for the adjustbox modifications, and whether that can be incorporated in \tikz as well:
\documentclass{article}
\usepackage{turnstile}% http://ctan.org/pkg/turnstile
\usepackage{tikz}% http://ctan.org/pkg/pgf
\renewcommand{\makehor}[4]
{\ifthenelse{\equal{#1}{n}}{\hspace{#3}}{}
\ifthenelse{\equal{#1}{s}}{\rule[-0.5#2]{#3}{#2}}{}
\ifthenelse{\equal{#1}{d}}{\setlength{\lengthvar}{#2}
\rule[-\lengthvar]{#3}{#2}
\hspace{-#3}
\rule[0.5#4]{#3}{#2}}{}
\ifthenelse{\equal{#1}{t}}{\setlength{\lengthvar}{1.5#2}
\rule[-\lengthvar]{#3}{#2}
\hspace{-#3}
\rule[-0.5#2]{#3}{#2}
\hspace{-#3}
\setlength{\lengthvar}{0.5#2}
\rule[\lengthvar]{#3}{#2}}{}
\ifthenelse{\equal{#1}{w}}{% New wavy $\sim$ definition
\setbox0=\hbox{$\sim$}%
\ifthenelse{\equal{#1}{z}}{% New tikz wavy definition
\raisebox{-.4ex}{\hspace*{-.08ex}\tikz \draw [thin,x=0.5ex,y=.25ex] (0,0) sin (1,1) cos (2,0) sin (3,-1) cos (4,0);\hspace*{.2ex}}}{}
}
\begin{document}
$\renewcommand{\arraystretch}{2}% \begin{array}{lll} \textrm{Regular}\ \verb!s! & \textrm{Wavy}\ \verb!w! & \textrm{TikZ}\ \verb!z! \\ \hline A\turnstile{s}{s}{}{}{n}B & A\turnstile{s}{w}{}{}{n}B & A\turnstile{s}{z}{}{}{n}B \\ A\turnstile{s}{s}{L}{}{n}B & A\turnstile{s}{w}{L}{}{n}B & A\turnstile{s}{z}{L}{}{n}B \\ A\turnstile{s}{s}{}{D}{n}B & A\turnstile{s}{w}{}{D}{n}B & A\turnstile{s}{z}{}{D}{n}B \\ A\turnstile{s}{s}{L}{D}{n}B & A\turnstile{s}{w}{L}{D}{n}B & A\turnstile{s}{z}{L}{D}{n}B \end{array}$
\end{document}
It needs improvement for a number of reasons:
1. There is a very minute difference in the typesetting of a "denominator-only" and "numerator+denominator" \turnstile. For example, look at the close-up between
2. Unexpected results may occur from adding the ending vertical line(s).
3. The spacing of the right operand (B in this case) is too far off. This can be accommodated by means of an intermediate macro, but it is best suited inside the \turnstile macro.
I think all of the above items would be addressed by someone with a better handle on tikz-related commands. But then again, perhaps this is not a problem.
• Wow! Nice answer! Would it be possible to make the wavy line such that it has the same thickness and edges as the vertical line? – N.N. Oct 21 '11 at 16:18
• Thanks for you improvement. I'll award you the bounty for the effort. I agree that the TikZ variant needs improvements, especially the horizontal spacing for the right operand and the vertical spacing for the lower subscript needs to be fixed (the symbols end up too close to the wavy line). What would the best way to get some TikZ wizard attention to it? Maybe to start a new question and ask for improvements to your TikZ solution? – N.N. Nov 2 '11 at 9:16
• @N.N.: I agree that a new question would probably do it justice and it should additionally be labelled as tikz-specific. Perhaps a question with general intent, like "How to make a math symbol using tikz?" but with specific application to "sceptical consequence". Or you could also just make up some symbols to draw some attention as to what you exactly want, being specific about possible additions - like in this question, turnstile allows for adding lines via different commands. That's perhaps a bit too much, I know. – Werner Nov 2 '11 at 14:29
If you desire to have a symbol adjust based on the size of the surrounding text, the solution from Symbol for skeptical consequence can be enhanced to accept two additional parameters for the upper and lower characters.
Update: As requested in the comments, I also added an optional first parameter (defaults \sim) which defines the horizontal character to be used. Here is the output with three different horizontal symbols:
\documentclass[border=2pt]{standalone}
\usepackage{amsmath}% only needed for \dfrac
\usepackage{graphicx}% needed for \scalebox
\usepackage{pgf}% needed for the math calculations
% http://math.arizona.edu/~aprl/publications/mathclap/
\def\mathrlap{\mathpalette\mathrlapinternal}%
\def\mathrlapinternal#1#2{\rlap{$\mathsurround=0pt#1{#2}$}}%
\makeatletter
\newdimen\@mydimen%
\newdimen\@myHeightOfBar%
\settoheight{\@myHeightOfBar}{$|$}%
\newcommand{\SetScaleFactor}[1]{%
\settoheight{\@mydimen}{#1}%
\pgfmathsetmacro{\scaleFactor}{\@mydimen/\@myHeightOfBar}%
}%
\newcommand*{\Scale}[2][3]{\scalebox{#1}{\ensuremath{#2}}}%
\newcommand*{\nct}[5][\sim]{%
\SetScaleFactor{\vphantom{\ensuremath{#2#3}}}% Compute scale to be applied
#2%
\mathrel{\Scale[\scaleFactor]{|\mathrlap{\kern-0.48ex{\substack{{\scriptscriptstyle #5}\\[-0.5ex]#1\\[-0.6ex]{\scriptscriptstyle #4}}}}\hphantom{\kern-0.90ex\sim}}}%
#3%
}%
\begin{document}
$\nct{a}{b}{l}{u} \qquad \nct{\frac{A}{C}}{B}{l}{u} \qquad \nct{\dfrac{A}{C}}{B}{l}{u}$\par
$\nct[-]{a}{b}{l}{u} \qquad \nct[-]{\frac{A}{C}}{B}{l}{u} \qquad \nct[-]{\dfrac{A}{C}}{B}{l}{u}$\par
$\nct[=]{a}{b}{l}{u} \qquad \nct[=]{\frac{A}{C}}{B}{l}{u} \qquad \nct[=]{\dfrac{A}{C}}{B}{l}{u}$
\end{document}
• Can this solution be adapted to also draw normal turnstiles so that there's a matching pair (straight and wavy horizontal line)? – N.N. Oct 21 '11 at 21:30
• Have updated solution to accept an optional first parameter so you can also have a horizontal line. – Peter Grill Oct 21 '11 at 22:09
|
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|
http://aas.org/archives/BAAS/v32n2/aas196/134.htm
|
AAS 196th Meeting, June 2000
Session 37. X-Ray Results from Chandra and XMM
Topical Contributed Display, Wednesday, June 7, 2000, 10:00am-7:00pm, Empire Hall South
## [37.01] Star Formation near the X-ray Jet in Cen A (NGC5128)
J.A. Graham (Carnegie-DTM), C.I. Fassett (Williams College)
Blue stars are identified in the region of the inner gaseous filaments (Blanco et al. ApJ 198, L63, 1975) and the X-ray jet (Kraft et al. ApJ 531, L9, 2000) NE of the main body of the radio galaxy NGC5128 (Cen A). Comparison between the X-ray contours and optical images shows that the X-ray jet passes through the diffuse region DF5 and just N of DF6 as identified in Dufour & van den Bergh (ApJ 226, L73, 1978). From the scale on the web image (http://chandra.harvard.edu), the X-ray jet extends there almost to the inner filaments themselves. In an 8\arcmin .8 \times 8 \arcmin .8 field centered on the inner filaments, UBV photometry has been obtained for stars brighter than V = 24m.5. The measurements were made on CCD images obtained with the 2.5m du Pont telescope at Las Campanas Observatory. The photometry has been used to identify faint blue stars which most likely formed from the interaction of the jet with local concentrations of dust and gas. The region DF6 is resolved into a cluster containing luminous blue stars which are evidently very young. Other loose groups are observed but compared with the aggregates seen further out (Graham ApJ 502, 245 1998), these inner stars are spread much more widely over the 9\arcmin field. However, the brightest and presumably the youngest blue stars lie close to the X-ray jet. We suggest that, in this case, the raw material for star formation is to be found in the many small dust patches or globules, seen silhouetted against the galaxy and that star formation is again triggered by shocks initiated by the jet. The brightest blue object, which is measurably diffuse and may be a very young globular cluster, is located at the southern edge of optical knot A (Graham & Price ApJ 247, 813, 1981). Our preliminary photometry is V = 20m.11, B-V = +0m.32, U-B = -1m.09. There are no velocity data for the blue stars but we suspect that they are dispersing into the NGC5128 halo even more rapidly than their counterparts in the outlying field (Fassett & Graham ApJ (in press), 2000).
|
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|
https://www.mendeley.com/papers/uptake-water-tablets-lowsubstituted-carboxymethyl-cellulose-sodium-disintegrant/
|
## Uptake of water into tablets with low-substituted carboxymethyl cellulose sodium as disintegrant
• Wan L
• 5
• 18
Citations
#### Abstract
Low-substituted carboxymethylcellulose sodium (Nymcel ZSB 10, ZSD 16) which differ in the degree of substitution were used as disintegrants in sulphanilamide tablets formulated with methylcellulose (MC) of varying viscosity as a binder. The disintegration time of tablets with ZSD 16 was much higher than that of tablets containing ZSB 10 due to the higher content of water-soluble substances in the former. Both in the presence and absence of MC the disintegration time increased with increasing concentration of either ZSB 10 or ZSD 16. Water uptake in tablets with MC and either of the two disintegrants followed the order: 1.25% > 5% > 2.5% Nymcel. The higher uptake at 5% disintegrant level did not however result in a lower disintegration time which was also found to decrease with an increase in the viscosity of MC. This was accompanied with increasing water uptake due to the higher hydration capacity of high viscosity MC. Both grades of low-substituted carboxymethylcellulose sodium were most effective when used in low concentrations. When observed microscopically ZSB 10 particles were found to swell more than those of ZSD 16. © 1989.
#### Author-supplied keywords
• Disintegration
• Low-substituted carboxymethylcellulose sodium
• Methylcellulose
• Swelling
• Water penetration
#### Cite this document
Choose a citation style from the tabs below
Save time finding and organizing research with Mendeley
|
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|
https://worldwidescience.org/topicpages/v/varying+strengths+depending.html
|
#### Sample records for varying strengths depending
1. Attitudes as Object-Evaluation Associations of Varying Strength
OpenAIRE
Fazio, Russell H.
2007-01-01
Historical developments regarding the attitude concept are reviewed, and set the stage for consideration of a theoretical perspective that views attitude, not as a hypothetical construct, but as evaluative knowledge. A model of attitudes as object-evaluation associations of varying strength is summarized, along with research supporting the model’s contention that at least some attitudes are represented in memory and activated automatically upon the individual’s encountering the attitude objec...
2. Spall Strength Measurements of Concrete for Varying Aggregate Sizes
International Nuclear Information System (INIS)
Chhabildas, Lalit C.; Kipp, Marlin E.; Reinhart, William D.; Wilson, Leonard T.
1999-01-01
Controlled impact experiments have been performed to determine the spall strength of four different concrete compositions. The four concrete compositions are identified as, 'SAC-5, CSPC', (''3/4'') large, and (''3/8'') small, Aggregate. They differ primarily in aggregate size but with average densities varying by less than five percent. Wave profiles from sixteen experiments, with shock amplitudes of 0.07 to 0.55 GPa, concentrate primarily within the elastic regime. Free-surface particle velocity measurements indicate consistent pullback signals in the release profiles, denoting average span strength of approximately 40 MPa. It is the purpose of this paper to present spall measurements under uniaxial strain loading. Notwithstanding considerable wave structure that is a unique characteristic to the heterogeneous nature of the scaled concrete, the spall amplitudes appear reproducible and consistent over the pressure range reported in this study
Science.gov (United States)
Davis, Bette; Gaul, W. C.
2007-01-01
This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.
4. Induction of Ca2+-dependent cyclosporin A-insensitive nonspecific permeability of the inner membrane of liver mitochondria and cytochrome c release by α,ω-hexadecanedioic acid in media of varying ionic strength.
Science.gov (United States)
Dubinin, M V; Vedernikov, A A; Khoroshavina, E I; Samartsev, V N
2014-06-01
In liver mitochondria loaded with Ca2+ or Sr(2+), α,ω-hexadecanedioic acid (HDA) can induce nonspecific permeability of the inner membrane (mitochondrial pore) by the mechanism insensitive to cyclosporin A (CsA). In this work we studied the effect of ionic strength of the incubation medium on the kinetics of the processes that accompany Ca2+-dependent induction of the mitochondrial pore by fatty acid: organelle swelling, Ca2+ release from the matrix, changes in transmembrane potential (Δψ) and rate of oxygen consumption, and the release of cytochrome c from the intermembrane space. Two basic incubation media were used: sucrose medium and isotonic ionic medium containing KCl without sucrose. We found that 200 μM Ca2+ and 20 μM HDA in the presence of CsA effectively induce high-amplitude swelling of mitochondria both in the case of sucrose and in the ionic incubation medium. In the presence of CsA, mitochondria can rapidly absorb Ca2+ and retain it in the matrix for a while without reducing Δψ. Upon incubation in the ionic medium, mitochondria retain most of the added Ca2+ in the matrix for a short time without reducing the Δψ. In both cases the addition of HDA to the mitochondria 2 min after the introduction of Ca2+ leads to the rapid release of these ions from the matrix and total drop in Δψ. The mitochondrial swelling induced by Ca2+ and HDA in non-ionic medium is accompanied by almost maximal stimulation of respiration. Under the same conditions, but during incubation of mitochondria in the ionic medium, it is necessary to add cytochrome c for significant stimulation of respiration. The mitochondrial swelling induced by Ca2+ and HDA leads to the release of cytochrome c in a larger amount in the case of ionic medium than for the sucrose medium. We conclude that high ionic strength of the incubation medium determines the massive release of cytochrome c from mitochondria and liberates it from the respiratory chain, which leads to blockade of electron
5. Strength of Gamma Rhythm Depends on Normalization
Science.gov (United States)
Ray, Supratim; Ni, Amy M.; Maunsell, John H. R.
2013-01-01
Neuronal assemblies often exhibit stimulus-induced rhythmic activity in the gamma range (30–80 Hz), whose magnitude depends on the attentional load. This has led to the suggestion that gamma rhythms form dynamic communication channels across cortical areas processing the features of behaviorally relevant stimuli. Recently, attention has been linked to a normalization mechanism, in which the response of a neuron is suppressed (normalized) by the overall activity of a large pool of neighboring neurons. In this model, attention increases the excitatory drive received by the neuron, which in turn also increases the strength of normalization, thereby changing the balance of excitation and inhibition. Recent studies have shown that gamma power also depends on such excitatory–inhibitory interactions. Could modulation in gamma power during an attention task be a reflection of the changes in the underlying excitation–inhibition interactions? By manipulating the normalization strength independent of attentional load in macaque monkeys, we show that gamma power increases with increasing normalization, even when the attentional load is fixed. Further, manipulations of attention that increase normalization increase gamma power, even when they decrease the firing rate. Thus, gamma rhythms could be a reflection of changes in the relative strengths of excitation and normalization rather than playing a functional role in communication or control. PMID:23393427
6. Evaluation of size dependent design shear strength of reinforced ...
to the development of the size dependent models on the shear strength in ... predict the diagonal cracking strength and the ultimate shear strength of RC ... ing strength of normal beams was by Zsutty (1968) based on the data base available without .... The comparison of the calculated shear strength of the beams is shown.
7. Arguments Whose Strength Depends on Continuous Variation
Directory of Open Access Journals (Sweden)
James Franklin
2013-03-01
Full Text Available Both the traditional Aristotelian and modern symbolic approaches to logic have seen logic in terms of discrete symbol processing. Yet there are several kinds of argument whose validity depends on some topological notion of continuous variation, which is not well captured by discrete symbols. Examples include extrapolation and slippery slope arguments, sorites, fuzzy logic, and those involving closeness of possible worlds. It is argued that the natural first attempts to analyze these notions and explain their relation to reasoning fail, so that ignorance of their nature is profound.
8. Military Dependence on Commercial Satellite Communications Systems - Strength or Vulnerability
National Research Council Canada - National Science Library
Hook, Jack
1999-01-01
The military's growing dependence on commercial satellite communications systems will become a strength or vulnerability based on how well the right balance is achieved between commercial and military systems...
9. Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment
Directory of Open Access Journals (Sweden)
Mu Zhou
2014-01-01
Full Text Available This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs in logarithmic received signal strength (RSS varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future.
10. Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment
Science.gov (United States)
Tian, Zengshan; Xu, Kunjie; Yu, Xiang
2014-01-01
This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs) as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future. PMID:24683349
11. Time varying behavior of the loudspeaker suspension: Displacement level dependency
DEFF Research Database (Denmark)
Agerkvist, Finn T.; Pedersen, Bo Rohde
2009-01-01
The compliance of the loudspeaker suspension is known to depend on the recent excitation level history. Previous investigations have shown that the electrical power as well as displacement and velocity plays a role. In this paper the hypothesis that the changes in compliance are caused mainly...... by how much the suspension has been stretched, i.e. the maximum displacement, is investigated. For this purpose the changes in compliance are measured when exposing the speaker to different levels and types of electrical excitation signals, as well as mechanical excitation only. For sinusoidal excitation...... the change in compliance is shown to depend primarily on maximum displacement. But for square pulse excitation the duration of the excitation also plays an important role...
12. Molecular Mechanisms That Underlie the Dynamic Adaptation of Innate Monocyte Memory to Varying Stimulant Strength of TLR Ligands.
Science.gov (United States)
Yuan, Ruoxi; Geng, Shuo; Li, Liwu
2016-01-01
13. Molecular mechanisms that underlie the dynamic adaptation of innate monocyte memory to varying stimulant strength of TLR ligands
Directory of Open Access Journals (Sweden)
Ruoxi Yuan
2016-11-01
14. Conceptual design of a compact high gradient quadrupole magnet of varying strength using permanent magnets
Directory of Open Access Journals (Sweden)
Gautam Sinha
2018-02-01
Full Text Available A concept is presented to design magnets using cylindrical-shaped permanent-magnet blocks, where various types of magnetic fields can be produced by either rotating or varying the size of the magnetic blocks within a given mechanical structure. A general method is introduced to calculate the 3D magnetic field produced by a set of permanent magnets. An analytical expression of the 2D field and the condition to generate various magnetic fields like dipole, quadrupole, and sextupole are derived. Using the 2D result as a starting point, a computer code is developed to get the optimum orientation of the magnets to obtain the user-specific target field profile over a given volume in 3D. Designs of two quadrupole magnets are presented, one using 12 and the other using 24 permanent-magnet blocks. Variation of the quadrupole strength is achieved using tuning coils of a suitable current density and specially designed end tubes. A new concept is introduced to reduce the integrated quadrupole field strength by inserting two hollow cylindrical tubes made of iron, one at each end. This will not affect the field gradient at the center but reduce the integrated field strength by shielding the magnetic field near the ends where the tubes are inserted. The advantages of this scheme are that it is easy to implement, the magnetic axis will not shift, and it will prevent interference with nearby devices. Around 40% integrated field variation is achieved using this method in the present example. To get a realistic estimation of the field quality, a complete 3D model using a nonlinear B-H curve is also studied using a finite-element-based computer code. An example to generate around an 80 T/m quadrupole field gradient is also presented.
15. Conceptual design of a compact high gradient quadrupole magnet of varying strength using permanent magnets
Science.gov (United States)
Sinha, Gautam
2018-02-01
A concept is presented to design magnets using cylindrical-shaped permanent-magnet blocks, where various types of magnetic fields can be produced by either rotating or varying the size of the magnetic blocks within a given mechanical structure. A general method is introduced to calculate the 3D magnetic field produced by a set of permanent magnets. An analytical expression of the 2D field and the condition to generate various magnetic fields like dipole, quadrupole, and sextupole are derived. Using the 2D result as a starting point, a computer code is developed to get the optimum orientation of the magnets to obtain the user-specific target field profile over a given volume in 3D. Designs of two quadrupole magnets are presented, one using 12 and the other using 24 permanent-magnet blocks. Variation of the quadrupole strength is achieved using tuning coils of a suitable current density and specially designed end tubes. A new concept is introduced to reduce the integrated quadrupole field strength by inserting two hollow cylindrical tubes made of iron, one at each end. This will not affect the field gradient at the center but reduce the integrated field strength by shielding the magnetic field near the ends where the tubes are inserted. The advantages of this scheme are that it is easy to implement, the magnetic axis will not shift, and it will prevent interference with nearby devices. Around 40% integrated field variation is achieved using this method in the present example. To get a realistic estimation of the field quality, a complete 3D model using a nonlinear B -H curve is also studied using a finite-element-based computer code. An example to generate around an 80 T /m quadrupole field gradient is also presented.
16. Dependence of the giant dipole strength function on excitation energy
International Nuclear Information System (INIS)
Draper, J.E.; Newton, J.O.; Sobotka, L.G.; Lindenberger, H.; Wozniak, G.J.; Moretto, L.G.; Stephens, F.S.; Diamond, R.M.; McDonald, R.J.
1982-01-01
Spectra of γ rays associated with deep-inelastic products from the 1150-MeV 136 Xe+ 181 Ta reaction have been measured. The yield of 10--20-MeV γ rays initially increases rapidly with the excitation energy of the products and then more slowly for excitation energies in excess of 120 MeV. Statistical-model calculations with ground-state values of the giant dipole strength function fail to reproduce the shape of the measured γ-ray spectra. This suggests a dependence of the giant dipole strength function on excitation energy
17. Fatigue strength depending on position of cracks for weldments
International Nuclear Information System (INIS)
Lee, Hae Woo; Park, Won Jo
2006-01-01
This is a study of fatigue strength of weld deposits with transverse cracks in plate up to 50 mm thick. It is concerned with the fatigue properties of welds already with transverse cracks. A previous study of transverse crack occurrence, location and microstructure in accordance with welding conditions was published in the Welding Journal (Lee et al., 1998). A fatigue crack develops as a result of stress concentration and extends with each load cycle until fatigue occurs, or until the cyclic loads are transferred to redundant members. The fatigue performance of a member is more dependent on the localized state of stress than the static strength of the base metal or the weld metal. Fatigue specimens were machined to have transverse cracks located on the surface and inside the specimen. Evaluation of fatigue strength depending on location of transverse cracks was then performed. When transverse cracks were propagated in a quarter-or half-circle shape, the specimen broke at low cycle in the presence of a surface crack. However, when the crack was inside the specimen, it propagated in a circular or elliptical shape and the specimen showed high fatigue strength, enough to reach the fatigue limit within tolerance of design stresses
18. ZigBee’s Received Signal Strength and Latency Evaluation under Varying Environments
Directory of Open Access Journals (Sweden)
H. H. R. Sherazi
2016-01-01
Full Text Available Being self-configured, self-organized, and self-healing low power technology, ZigBee has obtained significant attention in last few years for achieving ubiquitous communication among various devices within a Personal Area Network (PAN. Even after a decade of its emergence, it has been well serving the communication needs of numerous modern applications belonging to multiple industries and is still a spotlight for the researchers working on certain aspects to enhance productivity along with a major cost reduction. Despite its robust communication nature, it heavily depends upon the context and is prone to the external effects that may cause a serious threat to prospective applications. This paper presents the novel experimental analysis conducted on real test beds to evaluate the impact of continuously changing communication environment on various parameters, for example, RSSI (Received Signal Strength Indicator and latency in the presence of multiple obstacles that may lead to severe degradation in the overall performance. Eventually, we suggest a suitable frame size for ZigBee based on our results deduced from the experimental study.
19. Strength and deformation of shocked diamond single crystals: Orientation dependence
Science.gov (United States)
Lang, J. M.; Winey, J. M.; Gupta, Y. M.
2018-03-01
Understanding and quantifying the strength or elastic limit of diamond single crystals is of considerable scientific and technological importance, and has been a subject of long standing theoretical and experimental interest. To examine the effect of crystalline anisotropy on strength and deformation of shocked diamond single crystals, plate impact experiments were conducted to measure wave profiles at various elastic impact stresses up to ˜120 GPa along [110] and [111] crystal orientations. Using laser interferometry, particle velocity histories and shock velocities in the diamond samples were measured and were compared with similar measurements published previously for shock compression along the [100] direction. Wave profiles for all three orientations showed large elastic wave amplitudes followed by time-dependent inelastic deformation. From the measured wave profiles, the elastic limits were determined under well characterized uniaxial strain loading conditions. The measured elastic wave amplitudes for the [110] and [111] orientations were lower for higher elastic impact stress (stress attained for an elastic diamond response), consistent with the result reported previously for [100] diamond. The maximum resolved shear stress (MRSS) on the {111}⟨110⟩ slip systems was determined for each orientation, revealing significant orientation dependence. The MRSS values for the [100] and [110] orientations (˜33 GPa) are 25%-30% of theoretical estimates; the MRSS value for the [111] orientation is significantly lower (˜23 GPa). Our results demonstrate that the MRSS depends strongly on the stress component normal to the {111} planes or the resolved normal stress (RNS), suggesting that the RNS plays a key role in inhibiting the onset of inelastic deformation. Lower elastic wave amplitudes at higher peak stress and the effect of the RNS are inconsistent with typical dislocation slip mechanisms of inelastic deformation, suggesting instead an inelastic response
20. Dependence of Brownian and Néel relaxation times on magnetic field strength
International Nuclear Information System (INIS)
Deissler, Robert J.; Wu, Yong; Martens, Michael A.
2014-01-01
Purpose: In magnetic particle imaging (MPI) and magnetic particle spectroscopy (MPS) the relaxation time of the magnetization in response to externally applied magnetic fields is determined by the Brownian and Néel relaxation mechanisms. Here the authors investigate the dependence of the relaxation times on the magnetic field strength and the implications for MPI and MPS. Methods: The Fokker–Planck equation with Brownian relaxation and the Fokker–Planck equation with Néel relaxation are solved numerically for a time-varying externally applied magnetic field, including a step-function, a sinusoidally varying, and a linearly ramped magnetic field. For magnetic fields that are applied as a step function, an eigenvalue approach is used to directly calculate both the Brownian and Néel relaxation times for a range of magnetic field strengths. For Néel relaxation, the eigenvalue calculations are compared to Brown's high-barrier approximation formula. Results: The relaxation times due to the Brownian or Néel mechanisms depend on the magnitude of the applied magnetic field. In particular, the Néel relaxation time is sensitive to the magnetic field strength, and varies by many orders of magnitude for nanoparticle properties and magnetic field strengths relevant for MPI and MPS. Therefore, the well-known zero-field relaxation times underestimate the actual relaxation times and, in particular, can underestimate the Néel relaxation time by many orders of magnitude. When only Néel relaxation is present—if the particles are embedded in a solid for instance—the authors found that there can be a strong magnetization response to a sinusoidal driving field, even if the period is much less than the zero-field relaxation time. For a ferrofluid in which both Brownian and Néel relaxation are present, only one relaxation mechanism may dominate depending on the magnetic field strength, the driving frequency (or ramp time), and the phase of the magnetization relative to the
1. Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide.
Science.gov (United States)
Saliba, E; Abbassi-Ghadi, S; Vowles, R; Camilleri, J; Hooper, S; Camilleri, J
2009-04-01
To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement. The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests. Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement. Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.
2. Improving Delay-Range-Dependent Stability Condition for Systems with Interval Time-Varying Delay
Directory of Open Access Journals (Sweden)
Wei Qian
2013-01-01
Full Text Available This paper discusses the delay-range-dependent stability for systems with interval time-varying delay. Through defining the new Lyapunov-Krasovskii functional and estimating the derivative of the LKF by introducing new vectors, using free matrices and reciprocally convex approach, the new delay-range-dependent stability conditions are obtained. Two well-known examples are given to illustrate the less conservatism of the proposed theoretical results.
3. A dependent stress-strength interference model based on mixed copula function
Energy Technology Data Exchange (ETDEWEB)
Gao, Jian Xiong; An, Zong Wen; Liu, Bo [School of Mechatronics Engineering, Lanzhou University of Technology, Lanzhou (China)
2016-10-15
In the traditional Stress-strength interference (SSI) model, stress and strength must satisfy the basic assumption of mutual independence. However, a complex dependence between stress and strength exists in practical engineering. To evaluate structural reliability under the case that stress and strength are dependent, a mixed copula function is introduced to a new dependent SSI model. This model can fully characterize the dependence between stress and strength. The residual square sum method and genetic algorithm are also used to estimate the unknown parameters of the model. Finally, the validity of the proposed model is demonstrated via a practical case. Results show that traditional SSI model ignoring the dependence between stress and strength more easily overestimates product reliability than the new dependent SSI model.
4. Dependency of Shear Strength on Test Rate in SiC/BSAS Ceramic Matrix Composite at Elevated Temperature
Science.gov (United States)
Choi, Sung R.; Bansal, Narottam P.; Gyekenyesi, John P.
2003-01-01
Both interlaminar and in-plane shear strengths of a unidirectional Hi-Nicalon(TM) fiber-reinforced barium strontium aluminosilicate (SiC/BSAS) composite were determined at 1100 C in air as a function of test rate using double notch shear test specimens. The composite exhibited a significant effect of test rate on shear strength, regardless of orientation which was either in interlaminar or in in-plane direction, resulting in an appreciable shear-strength degradation of about 50 percent as test rate decreased from 3.3 10(exp -1) mm/s to 3.3 10(exp -5) mm/s. The rate dependency of composite's shear strength was very similar to that of ultimate tensile strength at 1100 C observed in a similar composite (2-D SiC/BSAS) in which tensile strength decreased by about 60 percent when test rate varied from the highest (5 MPa/s) to the lowest (0.005 MPa/s). A phenomenological, power-law slow crack growth formulation was proposed and formulated to account for the rate dependency of shear strength of the composite.
5. Delay-Dependent Guaranteed Cost Control of an Interval System with Interval Time-Varying Delay
Directory of Open Access Journals (Sweden)
Xiao Min
2009-01-01
Full Text Available This paper concerns the problem of the delay-dependent robust stability and guaranteed cost control for an interval system with time-varying delay. The interval system with matrix factorization is provided and leads to less conservative conclusions than solving a square root. The time-varying delay is assumed to belong to an interval and the derivative of the interval time-varying delay is not a restriction, which allows a fast time-varying delay; also its applicability is broad. Based on the Lyapunov-Ktasovskii approach, a delay-dependent criterion for the existence of a state feedback controller, which guarantees the closed-loop system stability, the upper bound of cost function, and disturbance attenuation lever for all admissible uncertainties as well as out perturbation, is proposed in terms of linear matrix inequalities (LMIs. The criterion is derived by free weighting matrices that can reduce the conservatism. The effectiveness has been verified in a number example and the compute results are presented to validate the proposed design method.
6. Delay-Dependent Asymptotic Stability of Cohen-Grossberg Models with Multiple Time-Varying Delays
Directory of Open Access Journals (Sweden)
Xiaofeng Liao
2007-01-01
Full Text Available Dynamical behavior of a class of Cohen-Grossberg models with multiple time-varying delays is studied in detail. Sufficient delay-dependent criteria to ensure local and global asymptotic stabilities of the equilibrium of this network are derived by constructing suitable Lyapunov functionals. The obtained conditions are shown to be less conservative and restrictive than those reported in the known literature. Some numerical examples are included to demonstrate our results.
7. Dependence of strength on particle size in graphite
International Nuclear Information System (INIS)
Kennedy, E.P.; Kennedy, C.R.
The strength to particle size relationship for specially fabricated graphites has been demonstrated and rationalized using fracture mechanics. In the past, similar studies have yielded empirical data using only commercially available material. Thus, experimental verification of these relationships has been difficult. However, the graphites of this study were fabricated by controlling the particle size ranges for a series of isotropic graphites. All graphites that were evaluated had a constant 1.85 g/cm 3 density. Thus, particle size was the only variable. This study also considered the particle size effect on other physical properties; coefficient of thermal expansion (CTE), electrical resistivity, fracture strain, and Young's modulus
8. Power dependence on the rotational strength in a quartz crystal
International Nuclear Information System (INIS)
Joshi, N.V.; Salcedo, D.; Gil, H.
2007-01-01
The rotational strength of optical activity has been examined as a function of power of the incident radiation in a quartz crystal for the first time. It has been observed that the angle of rotation is proportional to the square root of the intensity of the radiation. The present experimental data directly support the recently proposed model which takes into account the electronic polarizability rather than the atomic polarizability. This model explicitly explains the role of the incident power in estimating the angle of rotation
9. Prevalence and strength of density-dependent tree recruitment
Science.gov (United States)
Kai Zhu; Christopher W. Woodall; Joao V.D. Monteiro; James S. Clark
2015-01-01
Density dependence could maintain diversity in forests, but studies continue to disagree on its role. Part of the disagreement results from the fact that different studies have evaluated different responses (survival, recruitment, or growth) of different stages (seeds, seedlings, or adults) to different inputs (density of seedlings, density or distance to adults). Most...
10. Analysis of seafloor backscatter strength dependence on the survey azimuth using multibeam echosounder data
Science.gov (United States)
Lurton, Xavier; Eleftherakis, Dimitrios; Augustin, Jean-Marie
2018-06-01
The sediment backscatter strength measured by multibeam echosounders is a key feature for seafloor mapping either qualitative (image mosaics) or quantitative (extraction of classifying features). An important phenomenon, often underestimated, is the dependence of the backscatter level on the azimuth angle imposed by the survey line directions: strong level differences at varying azimuth can be observed in case of organized roughness of the seabed, usually caused by tide currents over sandy sediments. This paper presents a number of experimental results obtained from shallow-water cruises using a 300-kHz multibeam echosounder and specially dedicated to the study of this azimuthal effect, with a specific configuration of the survey strategy involving a systematic coverage of reference areas following "compass rose" patterns. The results show for some areas a very strong dependence of the backscatter level, up to about 10-dB differences at intermediate oblique angles, although the presence of these ripples cannot be observed directly—neither from the bathymetry data nor from the sonar image, due to the insufficient resolution capability of the sonar. An elementary modeling of backscattering from rippled interfaces explains and comforts these observations. The consequences of this backscatter dependence upon survey azimuth on the current strategies of backscatter data acquisition and exploitation are discussed.
11. Delay-dependent exponential stability for neural networks with discrete and distributed time-varying delays
International Nuclear Information System (INIS)
Zhu Xunlin; Wang Youyi
2009-01-01
This Letter studies the exponential stability for a class of neural networks (NNs) with both discrete and distributed time-varying delays. Under weaker assumptions on the activation functions, by defining a more general type of Lyapunov functionals and developing a new convex combination technique, new less conservative and less complex stability criteria are established to guarantee the global exponential stability of the discussed NNs. The obtained conditions are dependent on both discrete and distributed delays, are expressed in terms of linear matrix inequalities (LMIs), and contain fewer decision variables. Numerical examples are given to illustrate the effectiveness and the less conservatism of the proposed conditions.
12. Periodic solution for state-dependent impulsive shunting inhibitory CNNs with time-varying delays.
Science.gov (United States)
Şaylı, Mustafa; Yılmaz, Enes
2015-08-01
In this paper, we consider existence and global exponential stability of periodic solution for state-dependent impulsive shunting inhibitory cellular neural networks with time-varying delays. By means of B-equivalence method, we reduce these state-dependent impulsive neural networks system to an equivalent fix time impulsive neural networks system. Further, by using Mawhin's continuation theorem of coincide degree theory and employing a suitable Lyapunov function some new sufficient conditions for existence and global exponential stability of periodic solution are obtained. Previous results are improved and extended. Finally, we give an illustrative example with numerical simulations to demonstrate the effectiveness of our theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.
13. Muscle strength as a predictor of onset of ADL dependence in people aged 75 years
DEFF Research Database (Denmark)
Rantanen, Taina; Avlund, Kirsten; Suominen, Harri
2002-01-01
. For each muscle group tested, three equal groups were formed for men and women separately based on distributions of results. Those who reported being unable or needing help for eating, dressing, bathing, toileting, walking indoors or transferring from a bed or a chair were rated as ADL dependent....... Of the 227 initially ADL independent men, 21 (9.3%) became dependent in ADL. In women, the figures were 30 (8.8%) of 340. Multiple logistic regression models were used to predict the risk of ADL dependence in groups based on strength tertiles. After confirming that the association of muscle strength...... and incident ADL-dependence was similar in men and women, both genders were included in the same analyses adjusted for body weight and height, gender and research locality. Gender specific cut-offs were used for strength tertiles. All the strength tests predicted ADL dependence, with those being in the lowest...
14. Online Support Vector Regression with Varying Parameters for Time-Dependent Data
International Nuclear Information System (INIS)
2011-01-01
Support vector regression (SVR) is a machine learning technique that continues to receive interest in several domains including manufacturing, engineering, and medicine. In order to extend its application to problems in which datasets arrive constantly and in which batch processing of the datasets is infeasible or expensive, an accurate online support vector regression (AOSVR) technique was proposed. The AOSVR technique efficiently updates a trained SVR function whenever a sample is added to or removed from the training set without retraining the entire training data. However, the AOSVR technique assumes that the new samples and the training samples are of the same characteristics; hence, the same value of SVR parameters is used for training and prediction. This assumption is not applicable to data samples that are inherently noisy and non-stationary such as sensor data. As a result, we propose Accurate On-line Support Vector Regression with Varying Parameters (AOSVR-VP) that uses varying SVR parameters rather than fixed SVR parameters, and hence accounts for the variability that may exist in the samples. To accomplish this objective, we also propose a generalized weight function to automatically update the weights of SVR parameters in on-line monitoring applications. The proposed function allows for lower and upper bounds for SVR parameters. We tested our proposed approach and compared results with the conventional AOSVR approach using two benchmark time series data and sensor data from nuclear power plant. The results show that using varying SVR parameters is more applicable to time dependent data.
15. Duration dependence test for rational speculative bubble: the strength and weakness
OpenAIRE
2012-01-01
This review highlights the strength and weakness of duration dependence test used by Mokhtar, Nassir and Hassan (2006) to detect the rational speculative bubble in the Malaysian stock market. It is found that despite the test’s strength over the other tests, it is however sensitive to different specifications and therefore may produce contrasting results.
16. Delayed Ego Strength Development in Opioid Dependent Adolescents and Young Adults
Science.gov (United States)
Abramoff, Benjamin A.; Lange, Hannah L. H.; Matson, Steven C.; Cottrill, Casey B.; Bridge, Jeffrey A.; Abdel-Rasoul, Mahmoud; Bonny, Andrea E.
2015-01-01
Objective. To evaluate ego strengths, in the context of Erikson's framework, among adolescents and young adults diagnosed with opioid dependence as compared to non-drug using youth. Methods. Opioid dependent (n = 51) and non-drug using control (n = 31) youth completed the self-administered Psychosocial Inventory of Ego Strengths (PIES). The PIES assesses development in the framework of Erikson's ego strength stages. Multivariate linear regression modeling assessed the independent association of the primary covariate (opioid dependent versus control) as well as potential confounding variables (e.g., psychiatric comorbidities, intelligence) with total PIES score. Results. Mean total PIES score was significantly lower in opioid dependent youth (231.65 ± 30.39 opioid dependent versus 270.67 ± 30.06 control; p development. A treatment approach acknowledging this delay may be needed in the counseling and treatment of adolescents with opioid dependence. PMID:26664819
17. The magnitude and rate of reduction in strength, dexterity and sensation in the human hand vary with ageing.
Science.gov (United States)
Bowden, Jocelyn L; McNulty, Penelope A
2013-08-01
18. Solution to the monoenergetic time-dependent neutron transport equation with a time-varying source
International Nuclear Information System (INIS)
Ganapol, B.D.
1986-01-01
Even though fundamental time-dependent neutron transport problems have existed since the inception of neutron transport theory, it has only been recently that a reliable numerical solution to one of the basic problems has been obtained. Experience in generating numerical solutions to time-dependent transport equations has indicated that the multiple collision formulation is the most versatile numerical technique for model problems. The formulation coupled with a moment reconstruction of each collided flux component has led to benchmark-quality (four- to five-digit accuracy) numerical evaluation of the neutron flux in plane infinite geometry for any degree of scattering anisotropy and for both pulsed isotropic and beam sources. As will be shown in this presentation, this solution can serve as a Green's function, thus extending the previous results to more complicated source situations. Here we will be concerned with a time-varying source at the center of an infinite medium. If accurate, such solutions have both pedagogical and practical uses as benchmarks against which other more approximate solutions designed for a wider class of problems can be compared
19. Study on the effect of testing machine rigidity on strength and ductility temperature dependences obtained
International Nuclear Information System (INIS)
Krashchenko, V.P.; Statsenko, V.E.; Rudnitskij, N.P.
1984-01-01
Investigation procedures are described for rigidity of testing machines and mechanical properties of tantalum and nickel in the temperature range 293-1873K. Temperature dependences are presented for strength characteristics of the investigated materials obtained with the use of installations of different rigidity. Dependence analysis is carried out and recommendations are given as to the characteristics application
20. Responses to LBNP in men with varying profiles of strength and aerobic capacity: Implications for flight crews
Science.gov (United States)
Convertino, Victor A.; Mathes, Karen L.; Lasley, Mary L.; Tomaselli, Clare Marie; Frey, Mary Anne Bassett; Hoffler, G. Wyckliffe
1993-01-01
Hemodynamic and hormonal responses to lower-body negative pressure (LBNP) were examined in 24 healthy men to test the hypothesis that responsiveness of reflex control of blood pressure during orthostatic stress is associated with strength and/or aerobic capacity. Subjects underwent treadmill tests to determine peak oxygen uptake (peak VO2) and isokinetic dynamo meter tests to determine leg strength. Based on predetermined criteria, the subjects were classified into one of four fitness profiles of six subjects each matched for age, height, and weight: (1) low strength/low aerobic fitness; (2) low strength/high aerobic fitness; (3) high strength/low aerobic fitness; and (4) high strength/high aerobic fitness. Following 90 min of 6 degree head-down tilt (HDT), each subject underwent graded LBNP through -50 mmHg or presyncope, with maximal duration 15 min. All groups exhibited typical hemodynamic, hormonal, and fluid shift responses during LBNP, with no intergroup differences except for catecholamines. Seven subjects, distributed among the four fitness profiles, became presyncopal. Subjects who showed greatest reduction in mean arterial pressure (MAP) during LBNP had greater elevations in vasopressin and lesser increases in heart rate and peripheral resistance. Peak VO2 nor leg strength were correlated with fall in MAP or with syncopal episodes. We conclude that neither aerobic nor strength fitness characteristics are good predictors of responses to LBNP stress.
1. The stress-reducing effect of music listening varies depending on the social context.
Science.gov (United States)
Linnemann, Alexandra; Strahler, Jana; Nater, Urs M
2016-10-01
Given that music listening often occurs in a social context, and given that social support can be associated with a stress-reducing effect, it was tested whether the mere presence of others while listening to music enhances the stress-reducing effect of listening to music. A total of 53 participants responded to questions on stress, presence of others, and music listening five times per day (30min after awakening, 1100h, 1400h, 1800h, 2100h) for seven consecutive days. After each assessment, participants were asked to collect a saliva sample for the later analysis of salivary cortisol (as a marker for the hypothalamic-pituitary-adrenal axis) and salivary alpha-amylase (as a marker for the autonomic nervous system). Hierarchical linear modeling revealed that music listening per se was not associated with a stress-reducing effect. However, listening to music in the presence of others led to decreased subjective stress levels, attenuated secretion of salivary cortisol, and higher activity of salivary alpha-amylase. When listening to music alone, music that was listened to for the reason of relaxation predicted lower subjective stress. The stress-reducing effect of music listening in daily life varies depending on the presence of others. Music listening in the presence of others enhanced the stress-reducing effect of music listening independently of reasons for music listening. Solitary music listening was stress-reducing when relaxation was stated as the reason for music listening. Thus, in daily life, music listening can be used for stress reduction purposes, with the greatest success when it occurs in the presence of others or when it is deliberately listened to for the reason of relaxation. Copyright © 2016 Elsevier Ltd. All rights reserved.
2. Molecular dynamics simulation of thin film interfacial strength dependency on lattice mismatch
International Nuclear Information System (INIS)
Yang, Zhou; Lian, Jie; Wang, Junlan
2013-01-01
Laser-induced thin film spallation experiments have been previously developed to characterize the intrinsic interfacial strength of thin films. In order to gain insights of atomic level thin film debonding processes and the interfacial strength dependence on film/substrate lattice structures, in this study, molecular dynamics simulations of thin film interfacial failure under laser-induced stress waves were performed. Various loading amplitudes and pulse durations were employed to identify the optimum simulation condition. Stress propagation as a function of time was revealed in conjunction with the interface structures. Parametric studies confirmed that while the interfacial strength between a thin film and a substrate does not depend on the film thickness and the duration of the laser pulse, a thicker film and a shorter duration do provide advantage to effectively load the interface to failure. With the optimized simulation condition, further studies were focused on bulk Au/Au bi-crystals with mismatched orientations, and Ni/Al, Cu/Al, Cu/Ag and Cu/Au bi-crystals with mismatched lattices. The interfacial strength was found to decrease with increasing orientation mismatch and lattice mismatch but more significantly dominated by the bonding elements' atomic structure and valence electron occupancy. - Highlights: • Molecular dynamics simulation was done on stress wave induced thin film spallation. • Atomic structure was found to be a primary strength determining factor. • Lattice mismatch was found to be a secondary strength determining factor
3. Dependence of dipole transition gamma ray strength on the type of nucleus
International Nuclear Information System (INIS)
Cojocaru, V.; Stefanescu, Irina; Popescu, I.V.; Badica, T.; Olariu, A.
2000-01-01
The strength of gamma-ray transition is defined as the ratio between the experimental radiative width Γ γ and the theoretical radiative width calculated according to a model (for example Weisskopf single particle model, Γ W ). It is important to know on which parameters this strengths depend. In our previous work we put in evidence the dependence of the dipole transition gamma-ray strengths on the type of the nucleus. In this paper we look for a possible dependence of the quadrupole gamma-ray strengths on the type of nucleus (doubly-even, doubly-odd, with odd proton number and odd neutron number). All the input data are taken from the National Nuclear Data Center, Brookhaven. In order to demonstrate this possible dependence one can use the average of the strongest 10% transitions of given character. As the A dependence is concerned we use the following A-regions: 6-20, 21-44, 45-90, 91-150, 151-200. An average value for these transitions is also plotted both for the E2 and M2 transitions. Generally, all the functions log 10 vs A (S=Γ γ /Γ W ) have the same pattern as 'total' put in evidence by Endt. Moreover, there is a clear difference in the most A regions of the average S 10 values for different types of nuclei. As the RUL (Recommended Upper Limits W.u.) are concerned they have to be established as the highest experimental values of the transition strengths. In this work we suggest new RUL but this time in connection with the type of the nucleus. A table with the RUL depending on the nuclear type, for E2 and M2 transitions, respectively, is given. The number of M2 transitions is quite small. In this case, one might set the recommended upper limits with some precaution. (authors)
4. Time-varying extreme value dependence with application to leading European stock markets
KAUST Repository
Castro-Camilo, Daniela
2018-03-09
Extremal dependence between international stock markets is of particular interest in today’s global financial landscape. However, previous studies have shown this dependence is not necessarily stationary over time. We concern ourselves with modeling extreme value dependence when that dependence is changing over time, or other suitable covariate. Working within a framework of asymptotic dependence, we introduce a regression model for the angular density of a bivariate extreme value distribution that allows us to assess how extremal dependence evolves over a covariate. We apply the proposed model to assess the dynamics governing extremal dependence of some leading European stock markets over the last three decades, and find evidence of an increase in extremal dependence over recent years.
5. Time-varying extreme value dependence with application to leading European stock markets
KAUST Repository
Castro-Camilo, Daniela; de Carvalho, Miguel; Wadsworth, Jennifer
2018-01-01
Extremal dependence between international stock markets is of particular interest in today’s global financial landscape. However, previous studies have shown this dependence is not necessarily stationary over time. We concern ourselves with modeling extreme value dependence when that dependence is changing over time, or other suitable covariate. Working within a framework of asymptotic dependence, we introduce a regression model for the angular density of a bivariate extreme value distribution that allows us to assess how extremal dependence evolves over a covariate. We apply the proposed model to assess the dynamics governing extremal dependence of some leading European stock markets over the last three decades, and find evidence of an increase in extremal dependence over recent years.
6. Pupil dilation co-varies with memory strength of individual traces in a delayed response paired-associate task.
Directory of Open Access Journals (Sweden)
Hedderik van Rijn
Full Text Available Studies on cognitive effort have shown that pupil dilation is a reliable indicator of memory load. However, it is conceivable that there are other sources of effort involved in memory that also affect pupil dilation. One of these is the ease with which an item can be retrieved from memory. Here, we present the results of an experiment in which we studied the way in which pupil dilation acts as an online marker for memory processing during the retrieval of paired associates while reducing confounds associated with motor responses. Paired associates were categorized into sets containing either 4 or 7 items. After learning the paired associates once, pupil dilation was measured during the presentation of the retrieval cue during four repetitions of each set. Memory strength was operationalized as the number of repetitions (frequency and set-size, since having more items per set results in a lower average recency. Dilation decreased with increased memory strength, supporting the hypothesis that the amplitude of the evoked pupillary response correlates positively with retrieval effort. Thus, while many studies have shown that "memory load" influences pupil dilation, our results indicate that the task-evoked pupillary response is also sensitive to the experimentally manipulated memory strength of individual items. As these effects were observed well before the response had been given, this study also suggests that pupil dilation can be used to assess an item's memory strength without requiring an overt response.
7. Knee Muscle Strength at Varying Angular Velocities and Associations with Gross Motor Function in Ambulatory Children with Cerebral Palsy
Science.gov (United States)
Hong, Wei-Hsien; Chen, Hseih-Ching; Shen, I-Hsuan; Chen, Chung-Yao; Chen, Chia-Ling; Chung, Chia-Ying
2012-01-01
The aim of this study was to evaluate the relationships of muscle strength at different angular velocities and gross motor functions in ambulatory children with cerebral palsy (CP). This study included 33 ambulatory children with spastic CP aged 6-15 years and 15 children with normal development. Children with CP were categorized into level I (n =…
8. Alloy and composition dependence of hydrogen embrittlement susceptibility in high-strength steel fasteners
Science.gov (United States)
Brahimi, S. V.; Yue, S.; Sriraman, K. R.
2017-06-01
High-strength steel fasteners characterized by tensile strengths above 1100 MPa are often used in critical applications where a failure can have catastrophic consequences. Preventing hydrogen embrittlement (HE) failure is a fundamental concern implicating the entire fastener supply chain. Research is typically conducted under idealized conditions that cannot be translated into know-how prescribed in fastener industry standards and practices. Additionally, inconsistencies and even contradictions in fastener industry standards have led to much confusion and many preventable or misdiagnosed fastener failures. HE susceptibility is a function of the material condition, which is comprehensively described by the metallurgical and mechanical properties. Material strength has a first-order effect on HE susceptibility, which increases significantly above 1200 MPa and is characterized by a ductile-brittle transition. For a given concentration of hydrogen and at equal strength, the critical strength above which the ductile-brittle transition begins can vary due to second-order effects of chemistry, tempering temperature and sub-microstructure. Additionally, non-homogeneity of the metallurgical structure resulting from poorly controlled heat treatment, impurities and non-metallic inclusions can increase HE susceptibility of steel in ways that are measurable but unpredictable. Below 1200 MPa, non-conforming quality is often the root cause of real-life failures. This article is part of the themed issue 'The challenges of hydrogen and metals'.
9. Time-Dependent Behavior of High-Strength Kevlar and Vectran Webbing
Science.gov (United States)
Jones, Thomas C.; Doggett, William R.
2014-01-01
High-strength Kevlar and Vectran webbings are currently being used by both NASA and industry as the primary load-bearing structure in inflatable space habitation modules. The time-dependent behavior of high-strength webbing architectures is a vital area of research that is providing critical material data to guide a more robust design process for this class of structures. This paper details the results of a series of time-dependent tests on 1-inch wide webbing including an initial set of comparative tests between specimens that underwent realtime and accelerated creep at 65 and 70% of their ultimate tensile strength. Variability in the ultimate tensile strength of the webbings is investigated and compared with variability in the creep life response. Additional testing studied the effects of load and displacement rate, specimen length and the time-dependent effects of preconditioning the webbings. The creep test facilities, instrumentation and test procedures are also detailed. The accelerated creep tests display consistently longer times to failure than their real-time counterparts; however, several factors were identified that may contribute to the observed disparity. Test setup and instrumentation, grip type, loading scheme, thermal environment and accelerated test postprocessing along with material variability are among these factors. Their effects are discussed and future work is detailed for the exploration and elimination of some of these factors in order to achieve a higher fidelity comparison.
10. Delay-dependent exponential stability of cellular neural networks with time-varying delays
International Nuclear Information System (INIS)
Zhang Qiang; Wei Xiaopeng; Xu Jin
2005-01-01
The global exponential stability of cellular neural networks (CNNs) with time-varying delays is analyzed. Two new sufficient conditions ensuring global exponential stability for delayed CNNs are obtained. The conditions presented here are related to the size of delay. The stability results improve the earlier publications. Two examples are given to demonstrate the effectiveness of the obtained results
11. Gate dielectric strength dependent performance of CNT MOSFET and CNT TFET: A tight binding study
Directory of Open Access Journals (Sweden)
Md. Shamim Sarker
Full Text Available This paper presents a comparative study between CNT MOSFET and CNT TFET taking into account of different dielectric strength of gate oxide materials. Here we have studied the transfer characteristics, on/off current (ION/IOFF ratio and subthreshold slope of the device using Non Equilibrium Greens Function (NEGF formalism in tight binding frameworks. The results are obtained by solving the NEGF and Poisson’s equation self-consistently in NanoTCADViDES environment and found that the ON state performance of CNT MOSFET and CNT TFET have significant dependency on the dielectric strength of the gate oxide materials. The figure of merits of the devices also demonstrates that the CNT TFET is promising for high-speed and low-power logic applications. Keywords: CNT TFET, Subthreshold slop, Barrier width, Conduction band (C.B and Valance band (V.B, Oxide dielectric strength, Tight binding approach
12. Ionic strength dependence of stability constants, complexation of Molybdenum(V I) with EDTA
International Nuclear Information System (INIS)
Zare, K.; Majlesi, K.; Teimoori, F.
2002-01-01
The stability constant of Mo (Vi) complexes with EDTA in aqueous solution has been determined by various authors using different techniques, but according to literature, no work has been reported on ionic strength dependence of these complexes. The present work describes the complexation of Mo (Vi) with EDTA in an ionic strength range of 0.1 to 1.0 moldm - 3 s odium perchlorate at 25 d ig C . The complexation of molybdenum (Vi) with EDTA was investigated in aqueous solution ranging in ph from 5 to 7 using UV spectrophotometric techniques. The composition of the complex was determined by the continuous variations method. It was shown that molybdenum (Vi) forms a 2:1 complex with EDTA of the type (MoO 3 ) 2 L - 4 a t ph =5.5 The parameters that define the dependence on ionic strength were analyzed with the aim of obtaining further information regarding to their variation as a function of the charges involved in the complex reaction. Moreover, a Debye-Huckel type equation makes it possible to estimate a stability constant at a fixed ionic strength when its value is known at another ionic media in the range of 0.1 3 . Therefore the evaluation may make a significant contribution solving many analytical and speciation problems
13. Delay-Dependent Exponential Stability for Discrete-Time BAM Neural Networks with Time-Varying Delays
Directory of Open Access Journals (Sweden)
Yonggang Chen
2008-01-01
Full Text Available This paper considers the delay-dependent exponential stability for discrete-time BAM neural networks with time-varying delays. By constructing the new Lyapunov functional, the improved delay-dependent exponential stability criterion is derived in terms of linear matrix inequality (LMI. Moreover, in order to reduce the conservativeness, some slack matrices are introduced in this paper. Two numerical examples are presented to show the effectiveness and less conservativeness of the proposed method.
14. The importance of spatial models for estimating the strength of density dependence
DEFF Research Database (Denmark)
Thorson, James T.; Skaug, Hans J.; Kristensen, Kasper
2014-01-01
the California Coast. In this case, the nonspatial model estimates implausible oscillatory dynamics on an annual time scale, while the spatial model estimates strong autocorrelation and is supported by model selection tools. We conclude by discussing the importance of improved data archiving techniques, so...... that spatial models can be used to re-examine classic questions regarding the presence and strength of density dependence in wild populations Read More: http://www.esajournals.org/doi/abs/10.1890/14-0739.1...
15. Change of notch impact strength depending on radiation dose and test temperature
Directory of Open Access Journals (Sweden)
Martin Bednarik
2017-01-01
Full Text Available The main purpose of this paper has been determine the effect of radiation crosslinking on the notch impact strength of polyamides filled with fiberglass. These properties were examined in dependence on the dosage of the ionizing beta radiation (non-irradiated samples and those irradiated by dosage 66 and 132 kGy were compared and on the test temperature (23–150 °C.
16. The ability of familiarity, disruption, and the relative strength of nonenvironmental context cues to explain unreliable environmental-context-dependent memory effects in free recall.
Science.gov (United States)
Rutherford, A
2000-12-01
The ability of environmental-context (EC) familiarity, movement disruption, and the relative strength of memory cues to explain unreliable EC-dependent free-recall memory effects was examined in two experiments. Experiment 1 replicated Smith's (1979, Experiment 1) results confirming that familiarity and disruption cannot account for free-recall EC-reinstatement effects. In Experiment 2, a level of processing manipulation varied stimulus item memory cue strengths, and memory was again assessed by free recall. Contrary to Murnane and Phelps's (1995) and Dougal and Rotello's (1999) recognition findings, an EC-reinstatement effect was observed with low, but not high, levels of processing. However, comparisons across the two experiments revealed inconsistencies with the relative cue strength hypothesis. Consequently, a variant of the relative cue strength hypothesis that highlights the role of retrieval processes was proposed to explain the interaction between the levels of processing and the EC-reinstatement effect.
17. Life history traits influence the strength of distance- and density-dependence at different life stages of two Amazonian palms.
Science.gov (United States)
Choo, Juanita; Carasco, Cecilia; Alvarez-Loayza, Patricia; Simpson, Beryl B; Economo, Evan P
2017-07-01
18. Monoenergetic time-dependent neutron transport in an infinite medium with time-varying cross sections
International Nuclear Information System (INIS)
Ganapol, B.D.
1987-01-01
For almost 20 yr, the main thrust of the author's research has been the generation of as many benchmark solutions to the time-dependent monoenergetic neutron transport equation as possible. The major motivation behind this effort has been to provide code developers with highly accurate numerical solutions to serve as standards in the assessment of numerical transport algorithms. In addition, these solutions provide excellent educational tools since the important physical features of neutron transport are still present even though the problems solved are idealized. A secondary motivation, though of equal importance, is the intellectual stimulation and understanding provided by the combination of the analytical, numerical, and computational techniques required to obtain these solutions. Therefore, to further the benchmark development, the added complication of time-dependent cross sections in the one-group transport equation is considered here
19. Tensile properties and temperature-dependent yield strength prediction of GH4033 wrought superalloy
Energy Technology Data Exchange (ETDEWEB)
Ma, Jianzuo [State Key Laboratory of Coal Mine Disaster Dynamics and Control and College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Li, Weiguo, E-mail: [email protected] [State Key Laboratory of Coal Mine Disaster Dynamics and Control and College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Xianhe; Kou, Haibo; Shao, Jiaxing; Geng, Peiji; Deng, Yong [State Key Laboratory of Coal Mine Disaster Dynamics and Control and College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Fang, Daining [LTCS and College of Engineering, Peking University, Beijing 100871 (China)
2016-10-31
The tensile properties of superalloy GH4033 have been evaluated at temperatures ranging from room temperature to 1000 °C. Fracture surfaces and precipitation were observed using a field-emission scanning electron microscope (FE-SEM). The alloy mainly consisted of γ’ precipitate particles homogeneously dispersed in the γ matrix interior. The effects of dynamic strain aging and precipitation on the strength were verified. A temperature-dependent yield strength model was developed to describe the temperature and precipitation effects on the alloy's yield behaviour. The model is able to consider the effect of precipitation strengthening on the yield strength. The yield behaviour of the precipitation-strengthened superalloy was demonstrated to be adequately predictable over a wide range of temperatures. Note that this model reflects the quantitative relationship between the yield strength of the precipitation-strengthened superalloy and the temperature, the elastic modulus, the specific heat capacity at constant pressure, Poisson's ratio, the precipitate particle size and the volume fraction of the particles.
20. Magnetic field strength dependence of the magnetostriction of rare-earth iron garnets
International Nuclear Information System (INIS)
Zvezdin, A.K.; Levitin, R.Z.; Popov, A.I.; Silant'ev, V.I.
1981-01-01
The magnetostriction of holmium-yttrium iron garnets Hosub(x)Ysub(3-x)Fesub(5)Osub(12) (x=3 or 1.05) is measured in pulsed magnetic fields up to 200 kOe at 78 K. It is shown that the magnetostriction constants lambda 111 and lambda 100 of these ferrimagnets depends on the magnetic field strength. The magnetostriction constant of the iron garnet Ho 3 Fe 5 O 12 increases and of the iron garnet Hosub(1.05)Ysub(1.95)Fesub(5)Osub(12) decreases with increase of the field strength. The field dependences of the anisotropic magnetostriction constants lambda 111 and lambda 100 for Hosub(1.05)Ysub(1.95)Fesub(5)Osub(12) are fundamentally different. Thus lambda 111 depends quadratically on the total effective field Hsub(eff) whereas lambda 100 depends almost linearly on Hsub(eff). A theoretical analysis of the magneto-elastic interaction in rare-earth iron garnets is carried out [ru
1. Influence of postnatal glucocorticoids on hippocampal-dependent learning varies with elevation patterns and administration methods.
Science.gov (United States)
Claflin, Dragana I; Schmidt, Kevin D; Vallandingham, Zachary D; Kraszpulski, Michal; Hennessy, Michael B
2017-09-01
Recent interest in the lasting effects of early-life stress has expanded to include effects on cognitive performance. An increase in circulating glucocorticoids is induced by stress exposure and glucocorticoid effects on the hippocampus likely underlie many of the cognitive consequences. Here we review studies showing that corticosterone administered to young rats at the conclusion of the stress-hyporesponsiveness period affects later performance in hippocampally-mediated trace eyeblink conditioning. The nature and even direction of these effects varies with the elevation patterns (level, duration, temporal fluctuation) achieved by different administration methods. We present new time course data indicating that constant glucocorticoid elevations generally corresponded with hippocampus-mediated learning deficits, whereas acute, cyclical elevations corresponded with improved initial acquisition. Sensitivity was greater for males than for females. Further, changes in hippocampal neurogenesis paralleled some but not all effects. The findings demonstrate that specific patterns of glucocorticoid elevation produced by different drug administration procedures can have markedly different, sex-specific consequences on basic cognitive performance and underlying hippocampal physiology. Implications of these findings for glucocorticoid medications prescribed in childhood are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Matusevich, Yu.I.; Krul', L.P.
1992-01-01
The authors have studied the deformation vs. strength properties of radiation-crosslinked low-density polyethylene irradiated by γ irradiation up to doses from 5.0 sm-bullet 10 4 to 1.0 sm-bullet 10 6 Gy. The authors present the elongation diagrams taken at temperatures below and above the melting point of the polymer. The authors have obtained the dependences of the breaking stress and the pre-break elongation of the polymer on the irradiation doses and the testing temperature. Based on the kinetic lifetime equation, The authors calculated the values of the activation energy for mechanical fracture and the structure-sensitive coefficient γ. The authors show that in the crystalline state the strength of radiation-crosslinked polyethylene is determined by the chemical interactions along the chain of polymer macromolecules; and in molten polyethylene, by the crosslinks between the macromolecules. 8 refs., 4 figs., 1 tab
3. Studies of wheel-running reinforcement: parameters of Herrnstein's (1970) response-strength equation vary with schedule order.
Science.gov (United States)
Belke, T W
2000-05-01
Six male Wistar rats were exposed to different orders of reinforcement schedules to investigate if estimates from Herrnstein's (1970) single-operant matching law equation would vary systematically with schedule order. Reinforcement schedules were arranged in orders of increasing and decreasing reinforcement rate. Subsequently, all rats were exposed to a single reinforcement schedule within a session to determine within-session changes in responding. For each condition, the operant was lever pressing and the reinforcing consequence was the opportunity to run for 15 s. Estimates of k and R(O) were higher when reinforcement schedules were arranged in order of increasing reinforcement rate. Within a session on a single reinforcement schedule, response rates increased between the beginning and the end of a session. A positive correlation between the difference in parameters between schedule orders and the difference in response rates within a session suggests that the within-session change in response rates may be related to the difference in the asymptotes. These results call into question the validity of parameter estimates from Herrnstein's (1970) equation when reinforcer efficacy changes within a session.
4. Anatomical and Physiological Responses of Citrus Trees to Varying Boron Availability Is Dependent on Rootstock
Directory of Open Access Journals (Sweden)
Geisa Lima Mesquita
2016-03-01
Full Text Available In Citrus, water, nutrient transport and thereby fruit production, are influenced among other factors, by the interaction between rootstock and boron (B nutrition. This study aimed to investigate how B affects the anatomical structure of roots and leaves as well as leaf gas exchange in sweet orange trees grafted on two contrasting rootstocks in response to B supply. Plants grafted on Swingle citrumelo or Sunki mandarin were grown in a nutrient solution of varying B concentration (deficient, adequate, and excessive. Those grafted on Swingle were more tolerant to both B deficiency and toxicity than those on Sunki, as revealed by higher shoot and root growth. In addition, plants grafted on Sunki exhibited more severe anatomical and physiological damages under B deficiency, showing thickening of xylem cell walls and impairments in whole-plant, leaf-specific hydraulic conductance and leaf CO2 assimilation. Our data revealed that trees grafted on Swingle sustain better growth under low B availablitlity in the root medium and still respond positively to increased B levels by combining higher B absorption and root growth as well as better organization of xylem vessels. Taken together, those traits improved water and B transport to the plant canopy. Under B toxicity, Swingle rootstock would also favor plant growth by reducing anatomical and ultrastructural damage to leaf tissue and improving water transport compared with plants grafted on Sunki. From a practical point of view, our results highlight that B management in citrus orchards shall take into account rootstock varieties, of which the Swingle rootstock was characterized by its performance on regulating anatomical and ultrastructural damages, improving water transport and limiting negative impacts of B stress conditions on plant growth.
5. Anatomical and Physiological Responses of Citrus Trees to Varying Boron Availability Are Dependent on Rootstock.
Science.gov (United States)
Mesquita, Geisa L; Zambrosi, Fernando C B; Tanaka, Francisco A O; Boaretto, Rodrigo M; Quaggio, José A; Ribeiro, Rafael V; Mattos, Dirceu
2016-01-01
In Citrus, water, nutrient transport and thereby fruit production, are influenced among other factors, by the interaction between rootstock and boron (B) nutrition. This study aimed to investigate how B affects the anatomical structure of roots and leaves as well as leaf gas exchange in sweet orange trees grafted on two contrasting rootstocks in response to B supply. Plants grafted on Swingle citrumelo or Sunki mandarin were grown in a nutrient solution of varying B concentration (deficient, adequate, and excessive). Those grafted on Swingle were more tolerant to both B deficiency and toxicity than those on Sunki, as revealed by higher shoot and root growth. In addition, plants grafted on Sunki exhibited more severe anatomical and physiological damages under B deficiency, showing thickening of xylem cell walls and impairments in whole-plant leaf-specific hydraulic conductance and leaf CO2 assimilation. Our data revealed that trees grafted on Swingle sustain better growth under low B availablitlity in the root medium and still respond positively to increased B levels by combining higher B absorption and root growth as well as better organization of xylem vessels. Taken together, those traits improved water and B transport to the plant canopy. Under B toxicity, Swingle rootstock would also favor plant growth by reducing anatomical and ultrastructural damage to leaf tissue and improving water transport compared with plants grafted on Sunki. From a practical point of view, our results highlight that B management in citrus orchards shall take into account rootstock varieties, of which the Swingle rootstock was characterized by its performance on regulating anatomical and ultrastructural damages, improving water transport and limiting negative impacts of B stress conditions on plant growth.
6. Improved Criteria on Delay-Dependent Stability for Discrete-Time Neural Networks with Interval Time-Varying Delays
Directory of Open Access Journals (Sweden)
O. M. Kwon
2012-01-01
Full Text Available The purpose of this paper is to investigate the delay-dependent stability analysis for discrete-time neural networks with interval time-varying delays. Based on Lyapunov method, improved delay-dependent criteria for the stability of the networks are derived in terms of linear matrix inequalities (LMIs by constructing a suitable Lyapunov-Krasovskii functional and utilizing reciprocally convex approach. Also, a new activation condition which has not been considered in the literature is proposed and utilized for derivation of stability criteria. Two numerical examples are given to illustrate the effectiveness of the proposed method.
7. Delay-Dependent Guaranteed Cost H∞ Control of an Interval System with Interval Time-Varying Delay
Directory of Open Access Journals (Sweden)
Zhongke Shi
2009-01-01
Full Text Available This paper concerns the problem of the delay-dependent robust stability and guaranteed cost H∞ control for an interval system with time-varying delay. The interval system with matrix factorization is provided and leads to less conservative conclusions than solving a square root. The time-varying delay is assumed to belong to an interval and the derivative of the interval time-varying delay is not a restriction, which allows a fast time-varying delay; also its applicability is broad. Based on the Lyapunov-Ktasovskii approach, a delay-dependent criterion for the existence of a state feedback controller, which guarantees the closed-loop system stability, the upper bound of cost function, and disturbance attenuation lever for all admissible uncertainties as well as out perturbation, is proposed in terms of linear matrix inequalities (LMIs. The criterion is derived by free weighting matrices that can reduce the conservatism. The effectiveness has been verified in a number example and the compute results are presented to validate the proposed design method.
8. Controllable deterioration rate for time-dependent demand and time-varying holding cost
Directory of Open Access Journals (Sweden)
Mishra Vinod Kumar
2014-01-01
Full Text Available In this paper, we develop an inventory model for non-instantaneous deteriorating items under the consideration of the facts: deterioration rate can be controlled by using the preservation technology (PT during deteriorating period, and holding cost and demand rate both are linear function of time, which was treated as constant in most of the deteriorating inventory models. So in this paper, we developed a deterministic inventory model for non-instantaneous deteriorating items in which both demand rate and holding cost are a linear function of time, deterioration rate is constant, backlogging rate is variable and depend on the length of the next replenishment, shortages are allowed and partially backlogged. The model is solved analytically by minimizing the total cost of the inventory system. The model can be applied to optimizing the total inventory cost of non-instantaneous deteriorating items inventory for the business enterprises, where the preservation technology is used to control the deterioration rate, and demand & holding cost both are a linear function of time.
9. Delay-Dependent Stability Criteria of Uncertain Periodic Switched Recurrent Neural Networks with Time-Varying Delays
Directory of Open Access Journals (Sweden)
Xing Yin
2011-01-01
uncertain periodic switched recurrent neural networks with time-varying delays. When uncertain discrete-time recurrent neural network is a periodic system, it is expressed as switched neural network for the finite switching state. Based on the switched quadratic Lyapunov functional approach (SQLF and free-weighting matrix approach (FWM, some linear matrix inequality criteria are found to guarantee the delay-dependent asymptotical stability of these systems. Two examples illustrate the exactness of the proposed criteria.
10. Shear bond strength of composite to deep dentin after treatment with two different collagen cross-linking agents at varying time intervals.
Science.gov (United States)
Srinivasulu, S; Vidhya, S; Sujatha, M; Mahalaxmi, S
2012-01-01
This in vitro study evaluated the shear bond strength of composite resin to deep dentin using a total etch adhesive after treatment with two collagen cross-linking agents at varying time intervals. Thirty freshly extracted human maxillary central incisors were sectioned longitudinally into equal mesial and distal halves (n=60). The proximal deep dentin was exposed, maintaining a remaining dentin thickness (RDT) of approximately 1 mm. The specimens were randomly divided into three groups based on the surface treatment of dentin prior to bonding as follows: group I (n=12, control): no prior dentin surface treatment; group II (n=24): dentin surface pretreated with 10% sodium ascorbate; and group III (n=24): dentin surface pretreated with 6.5% proanthocyanidin. Groups II and III were further subdivided into two subgroups of 12 specimens each, based on the pretreatment time of five minutes (subgroup A) and 10 minutes (subgroup B). Shear bond strength of the specimens was tested with a universal testing machine, and the data were statistically analyzed. Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10% sodium ascorbate (group II) and 6.5% proanthocyanidin (group III) compared to the control group (group I). Among the collagen cross-linkers used, specimens treated with proanthocyanidin showed significantly higher shear bond strength values than those treated with sodium ascorbate. No significant difference was observed between the five-minute and 10-minute pretreatment times in groups II and III. It can be concluded that dentin surface pretreatment with both 10% sodium ascorbate and 6.5% proanthocyanidin resulted in significant improvement in bond strength of resin composite to deep dentin.
11. Temperature dependence of the fracture toughness and the cleavage fracture strength of a pressure vessel steel
International Nuclear Information System (INIS)
Kotilainen, H.
1980-01-01
A new model for the temperature dependence of the fracture toughness has been sought. It is based on the yielding processes at the crack tip, which are thought to be competitive with fracture. Using this method a good correlation between measured and calculated values of fracture toughness has been found for a Cr-Mo-V pressure vessel steel as well as for A533B. It has been thought that the application of this method can reduce the number of surveillance specimens in nuclear reactors. A method for the determination of the cleavage fracture strength has been proposed. 28 refs
12. Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis.
Science.gov (United States)
Michaelsen, Stella M; Ovando, Angélica C; Bortolotti, Adriano; Bandini, Bruno
2013-01-01
The extent to which muscle length affects force production in paretic lower limb muscles after stroke in comparison to controls has not been established. To investigate knee flexor strength deficits dependent on hip joint position in adults with hemiparesis and compare with healthy controls. a cross-sectional study with ten subjects with chronic (63±40 months) hemiparesis with mild to moderate lower limb paresis (Fugl-Meyer score 26±3) and 10 neurologically healthy controls. Isometric knee flexion strength with the hip positioned at 90° and 0° of flexion was assessed randomly on the paretic and non-paretic side of hemiparetic subjects and healthy controls. Subjects were asked to perform a maximal isometric contraction sustained for four seconds and measured by a dynamometer. The ratio of knee flexor strength between these two hip positions was calculated: Hip 0°/Hip 90°. Also, locomotor capacity was evaluated by the timed up and go test and by walking velocity over 10 meters. In subjects with hemiparesis, absolute knee flexion torque decreased (phemiparesis when compared to controls. More attention should be given to lower limb muscle strengthening exercises in individuals with stroke, with emphasis on the strengthening exercises in positions in which the muscle is shortened.
13. Effects of Menstrual Phase-Dependent Resistance Training Frequency on Muscular Hypertrophy and Strength.
Science.gov (United States)
Sakamaki-Sunaga, Mikako; Min, Seokki; Kamemoto, Kayoko; Okamoto, Takanobu
2016-06-01
The present study investigated how different training frequencies during menstrual phases affect muscle hypertrophy and strength. Fourteen eumenorrheic women performed 3 sets of arm curls (8-15 repetitions) until failure for 12 weeks. Depending on the menstrual cycle phase, each subject trained each arm separately after either a 3- or a 1-d·wk training protocol during the follicular phase (FP-T) and a 3- or 1-d·wk training protocol during the luteal phase (LP-T). Cross-sectional area (CSA), 1 repetition maximum, and maximum voluntary contraction significantly increased 6.2 ± 4.4, 36.4 ± 11.9, and 16.7 ± 5.6%, respectively (p ≤ 0.05 vs. before training), in the FP-T group and 7.8 ± 4.2, 31.8 ± 14.1, and 14.9 ± 12.7%, respectively (p ≤ 0.05 vs. before training), in the LP-T group. Changes in CSA between the FP-T and the LP-T groups significantly and positively correlated (r = 0.54, p ≤ 0.05). There were no major differences among the different training protocols with regard to muscle hypertrophy and strength. Therefore, we suggest that variations in female hormones induced by the menstrual cycle phases do not significantly contribute to muscle hypertrophy and strength gains during 12 weeks of resistance training.
14. Modeling the time-varying and level-dependent effects of the medial olivocochlear reflex in auditory nerve responses.
Science.gov (United States)
Smalt, Christopher J; Heinz, Michael G; Strickland, Elizabeth A
2014-04-01
The medial olivocochlear reflex (MOCR) has been hypothesized to provide benefit for listening in noisy environments. This advantage can be attributed to a feedback mechanism that suppresses auditory nerve (AN) firing in continuous background noise, resulting in increased sensitivity to a tone or speech. MOC neurons synapse on outer hair cells (OHCs), and their activity effectively reduces cochlear gain. The computational model developed in this study implements the time-varying, characteristic frequency (CF) and level-dependent effects of the MOCR within the framework of a well-established model for normal and hearing-impaired AN responses. A second-order linear system was used to model the time-course of the MOCR using physiological data in humans. The stimulus-level-dependent parameters of the efferent pathway were estimated by fitting AN sensitivity derived from responses in decerebrate cats using a tone-in-noise paradigm. The resulting model uses a binaural, time-varying, CF-dependent, level-dependent OHC gain reduction for both ipsilateral and contralateral stimuli that improves detection of a tone in noise, similarly to recorded AN responses. The MOCR may be important for speech recognition in continuous background noise as well as for protection from acoustic trauma. Further study of this model and its efferent feedback loop may improve our understanding of the effects of sensorineural hearing loss in noisy situations, a condition in which hearing aids currently struggle to restore normal speech perception.
15. Strain rate dependent tensile behavior of advanced high strength steels: Experiment and constitutive modeling
International Nuclear Information System (INIS)
Kim, Ji-Hoon; Kim, Daeyong; Han, Heung Nam; Barlat, F.; Lee, Myoung-Gyu
2013-01-01
High strain rate tensile tests were conducted for three advanced high strength steels: DP780, DP980 and TRIP780. A high strain rate tensile test machine was used for applying the strain rate ranging from 0.1/s to 500/s. Details of the measured stress–strain responses were comparatively analyzed for the DP780 and TRIP780 steels which show similar microstructural feature and ultimate tensile strength, but different strengthening mechanisms. The experimental observations included: usual strain rate dependent plastic flow stress behavior in terms of the yield stress (YS), the ultimate tensile strength (UTS), the uniform elongation (UE) and the total elongation (TE) which were observed for the three materials. But, higher strain hardening rate at early plastic strain under quasi-static condition than that of some increased strain rates was featured for TRIP780 steel, which might result from more active transformation during deformation with lower velocity. The uniform elongation that explains the onset of instability and the total elongation were larger in case of TRIP steel than the DP steel for the whole strain rate range, but interestingly the fracture strain measured by the reduction of area (RA) method showed that the TRIP steel has lower values than DP steel. The fractographs using scanning electron microscopy (SEM) at the fractured surfaces were analyzed to relate measured fracture strain and the microstructural difference of the two materials during the process of fracture under various strain rates. Finally, constitutive modeling for the plastic flow stresses under various strain rates was provided in this study. The proposed constitutive law could represent both Hollomon-like and Voce-like hardening laws and the ratio between the two hardening types was efficiently controlled as a function of strain rate. The new strength model was validated successfully under various strain rates for several grades of steels such as mild steels, DP780, TRIP780, DP980 steels.
16. New Delay-Dependent Stability Criteria for Uncertain Neutral Systems with Mixed Time-Varying Delays and Nonlinear Perturbations
Directory of Open Access Journals (Sweden)
Hamid Reza Karimi
2009-01-01
Full Text Available The problem of stability analysis for a class of neutral systems with mixed time-varying neutral, discrete and distributed delays and nonlinear parameter perturbations is addressed. By introducing a novel Lyapunov-Krasovskii functional and combining the descriptor model transformation, the Leibniz-Newton formula, some free-weighting matrices, and a suitable change of variables, new sufficient conditions are established for the stability of the considered system, which are neutral-delay-dependent, discrete-delay-range-dependent, and distributed-delay-dependent. The conditions are presented in terms of linear matrix inequalities (LMIs and can be efficiently solved using convex programming techniques. Two numerical examples are given to illustrate the efficiency of the proposed method.
17. Glucose-dependent insulinotropic polypeptide (GIP) receptor deletion leads to reduced bone strength and quality.
Science.gov (United States)
Mieczkowska, Aleksandra; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume
2013-10-01
Bone is permanently remodeled by a complex network of local, hormonal and neuronal factors that affect osteoclast and osteoblast biology. In this context, a role for gastro-intestinal hormones has been proposed based on evidence that bone resorption dramatically falls after a meal. Glucose-dependent insulinotropic polypeptide (GIP) is one of the candidate hormones as its receptor, glucose-dependent insulinotropic polypeptide receptor (GIPR), is expressed in bone. In the present study we investigated bone strength and quality by three-point bending, quantitative x-ray microradiography, microCT, qBEI and FTIR in a GIPR knockout (GIPR KO) mouse model and compared with control wild-type (WT) animals. Animals with a deletion of the GIPR presented with a significant reduction in ultimate load (--11%), stiffness (-16%), total absorbed (-28%) and post-yield energies (-27%) as compared with WT animals. Furthermore, despite no change in bone outer diameter, the bone marrow diameter was significantly increased and as a result cortical thickness was significantly decreased by 20% in GIPR deficient animals. Bone resorption at the endosteal surface was significantly increased whilst bone formation was unchanged in GIPR deficient animals. Deficient animals also presented with a pronounced reduction in the degree of mineralization of bone matrix. Furthermore, the amount of mature cross-links of collagen matrix was significantly reduced in GIPR deficient animals and was associated with lowered intrinsic material properties. Taken together, these data support a positive effect of the GIPR on bone strength and quality. © 2013.
18. Temperature and pinning strength dependence of the critical current of a superconductor with a square periodic array of pinning sites
International Nuclear Information System (INIS)
Benkraouda, M.; Obaidat, I.M.; Al Khawaja, U.
2006-01-01
We have conducted extensive series of molecular dynamic simulations on driven vortex lattices interacting with periodic square arrays of pinning sites. In solving the over damped equation of vortex motion we took into account the vortex-vortex repulsion interaction, the attractive vortex-pinning interaction, and the driving Lorentz force at several values of temperature. We have studied the effect of varying the driving Lorentz force and varying the pinning strength on the critical current for several pinning densities, and temperature values. We have found that the pinning strength play an important role in enhancing the critical current over the whole temperature range. At low temperatures, the critical current was found to increase linearly with increasing the pinning strengths for all pinning densities. As the temperature increases, the effect of small pinning strengths diminishes and becomes insignificant at high temperatures
19. New delay-dependent absolute stability criteria for Lur'e systems with time-varying delay
Science.gov (United States)
Chen, Yonggang; Bi, Weiping; Li, Wenlin
2011-07-01
In this article, the absolute stability problem is investigated for Lur'e systems with time-varying delay and sector-bounded nonlinearity. By employing the delay fractioning idea, the new augmented Lyapunov functional is first constructed. Then, by introducing some slack matrices and by reserving the useful term when estimating the upper bound of the derivative of Lyapunov functional, the new delay-dependent absolute stability criteria are derived in terms of linear matrix inequalities. Several numerical examples are presented to show the effectiveness and the less conservativeness of the proposed method.
20. Determination of the second virial coefficient of bovine serum albumin under varying pH and ionic strength by composition-gradient multi-angle static light scattering.
Science.gov (United States)
Ma, Yingfang; Acosta, Diana M; Whitney, Jon R; Podgornik, Rudolf; Steinmetz, Nicole F; French, Roger H; Parsegian, V Adrian
2015-01-01
Composition-gradient multi-angle static light scattering (CG-MALS) is an emerging technique for the determination of intermolecular interactions via the second virial coefficient B22. With CG-MALS, detailed studies of the second virial coefficient can be carried out more accurately and effectively than with traditional methods. In addition, automated mixing, delivery and measurement enable high speed, continuous, fluctuation-free sample delivery and accurate results. Using CG-MALS we measure the second virial coefficient of bovine serum albumin (BSA) in aqueous solutions at various values of pH and ionic strength of a univalent salt (NaCl). The systematic variation of the second virial coefficient as a function of pH and NaCl strength reveals the net charge change and the isoelectric point of BSA under different solution conditions. The magnitude of the second virial coefficient decreases to 1.13 x 10(-5) ml*mol/g(2) near the isoelectric point of pH 4.6 and 25 mM NaCl. These results illuminate the role of fundamental long-range electrostatic and van der Waals forces in protein-protein interactions, specifically their dependence on pH and ionic strength.
1. Dependence on zenith angle of the strength of 3-meter equatorial electrojet irregularities
International Nuclear Information System (INIS)
Ierkic, H.M.; Fejer, B.G.; Farley, D.T.
1980-01-01
Radar measurements in Peru were used to deduce the zenith angle dependence of the scattering cross section of plasma irregularities generated by instabilities in the equatorial electrojet. The irregularities probed by the 50 MHz Jicamarca radar had a wavelength of 3m. The cross section for the type 2 irregularities was isotopic in the plane perpendicular to the magnetic field, while the cross section for the stronger type 1 irregularities varied with zenith angle at a rate of approximately 0.3 dB/degree; the horizontally traveling waves were more than 100 times stronger than those traveling vertically
2. Implementation of a Stress-dependent Strength Material Model in PLAXIS 3D
DEFF Research Database (Denmark)
Knudsen, Bjørn S.; Østergaard, Martin Underlin; Clausen, Johan
To perform tests on bucket foundations, full-scale testing is rarely used since it is rather expensive. Instead small-scale testing is done to examine the static and dynamic behaviour of such structures. In the laboratory at Aalborg University, small-scale testing of offshore support structures can...... be performed in a pressure tank, where a pressure can be applied in order to simulate deep water situations. Since the test set-up is downscaled 15 to 30 times compared to real-life structures, stresses and strains will be downscaled too. For soils, normally a Mohr-Coulomb failure criterion is used......, and in the region of small stresses, a non-linear behaviour is observed - unlike the linear behaviour normally assumed in Mohr-Coulomb. To better model this non-linearity, a stress-dependent model for the strength of the soil material is sought to be implemented in PLAXIS 3D through FORTRAN to improve...
3. Dependence of transmittance and group index on the coupling strength between constituents of a metamaterial
International Nuclear Information System (INIS)
Thuy Vu, Tran Thanh; Lee, Young Pak; Nguyen, Thanh Tung; Rhee, Joo Yull; Vu, Dinh Lam
2011-01-01
Recent studies on the coupling effects between constituent elements of metamaterials have opened up a new gateway to many fascinating electromagnetic properties and functionalities that cannot be explained by the uncoupled point of view. In this work, we numerically investigated, in a THz regime, the coupling between a cut wire and a split-ring resonator, which gives rise to an interesting phenomenon—the so-called electromagnetically induced transparency-like effect. The trade-off between the maximum transmittance of the transmission window and the group index, which depends on the coupling strength between constituent elements, was systematically studied. Furthermore, by characterizing this trade-off by the transmittance-delay product (figure of merit), a criterion for slow-light applications was provided
4. A delay-dependent approach to robust control for neutral uncertain neural networks with mixed interval time-varying delays
International Nuclear Information System (INIS)
Lu, Chien-Yu
2011-01-01
This paper considers the problem of delay-dependent global robust stabilization for discrete, distributed and neutral interval time-varying delayed neural networks described by nonlinear delay differential equations of the neutral type. The parameter uncertainties are norm bounded. The activation functions are assumed to be bounded and globally Lipschitz continuous. Using a Lyapunov functional approach and linear matrix inequality (LMI) techniques, the stability criteria for the uncertain neutral neural networks with interval time-varying delays are established in the form of LMIs, which can be readily verified using the standard numerical software. An important feature of the result reported is that all the stability conditions are dependent on the upper and lower bounds of the delays. Another feature of the results lies in that it involves fewer free weighting matrix strategy, and upper bounds of the inner product between two vectors are not introduced to reduce the conservatism of the criteria. Two illustrative examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method
5. Strength and Anisotropy in Tournemire Shale: Temperature, Pressure and Time Dependences
Science.gov (United States)
Bonnelye, A.; Schubnel, A.; Zhi, G.; David, C.; Dick, P.
2017-12-01
Time and temperature dependent rock deformation has both scientific and socio-economic implications for natural hazards, the oil and gas industry and nuclear waste disposal. During the past decades, most studies on brittle creep have focused on igneous rocks and porous sedimentary rocks. To our knowledge, only few studies have been carried out on the brittle creep behavior of shale. We conducted a series of creep experiments on shale specimens coming from the French Institute for Nuclear Safety (IRSN) underground research laboratory located in Tournemire, France, under two different temperatures (26°C, 75°C) and confining pressures (10 MPa, 80 MPa), for three orientations (σ1along, perpendicular and 45° to bedding). In these long-term experiments (approximately 10 days), stress and strains were recorded continuously, while ultrasonic acoustic velocities were recorded every 1 15 minutes. The brittle creep failure stress of our Tournemire shale samples was systematically observed 50% higher than its short-term peak strength, with larger final axial strain accumulated. During creep, ultrasonic wave velocities first decreased, and then increased gradually. The magnitude of elastic wave velocity variations showed an important orientation and temperature dependence: velocities measured perpendicular to bedding showed increased variation, variation that was enhanced at higher temperature and higher pressure. The case of complete elastic anisotropy reversal was observed for sample deformed perpendicular to bedding, with amount of axial strain needed to reach anisotropy reversal reduced at higher temperature. SEM observations highlight the competition between crack growth, sealing/healing, and possibly mineral rotation, pressure solution or anisotropic compaction during creep defromation. Our study highlights that the short-term peak strength has little meaning in shale material, which can over-consolidate importantly by plastic' flow. In addition, we show that elastic
6. Dependence of frictional strength on compositional variations of Hayward fault rock gouges
Science.gov (United States)
Morrow, Carolyn A.; Moore, Diane E.; Lockner, David A.
2010-01-01
The northern termination of the locked portion of the Hayward Fault near Berkeley, California, is found to coincide with the transition from strong Franciscan metagraywacke to melange on the western side of the fault. Both of these units are juxtaposed with various serpentinite, gabbro and graywacke units to the east, suggesting that the gouges formed within the Hayward Fault zone may vary widely due to the mixing of adjacent rock units and that the mechanical behavior of the fault would be best modeled by determining the frictional properties of mixtures of the principal rock types. To this end, room temperature, water-saturated, triaxial shearing tests were conducted on binary and ternary mixtures of fine-grained gouges prepared from serpentinite and gabbro from the Coast Range Ophiolite, a Great Valley Sequence graywacke, and three different Franciscan Complex metasedimentary rocks. Friction coefficients ranged from 0.36 for the serpentinite to 0.84 for the gabbro, with four of the rock types having coefficients of friction ranging from 0.67-0.84. The friction coefficients of the mixtures can be predicted reliably by a simple weighted average of the end-member dry-weight percentages and strengths for all samples except those containing serpentinite. For the serpentinite mixtures, a linear trend between end-member values slightly overestimates the coefficients of friction in the midcomposition ranges. The range in strength for these rock admixtures suggests that both theoretical and numerical modeling of the fault should attempt to account for variations in rock and gouge properties.
7. Field strength and dose dependence of contrast enhancement by gadolinium-based MR contrast agents
International Nuclear Information System (INIS)
Rinck, P.A.; Muller, R.N.
1999-01-01
The relaxivities r 1 and r 2 of magnetic resonance contrast agents and the T 1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R 1 = 1/T 1 and R 2 = 1/T 2 ) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields. (orig.)
8. Transport methods: general. 2. Monte Carlo Particle Transport in Media with Exponentially Varying Time-Dependent Cross Sections
International Nuclear Information System (INIS)
Brown, Forrest B.; Martin, William R.
2001-01-01
We have investigated Monte Carlo schemes for analyzing particle transport through media with exponentially varying time-dependent cross sections. For such media, the cross sections are represented in the form Σ(t) = Σ 0 e -at (1) or equivalently as Σ(x) = Σ 0 e -bx (2) where b = av and v is the particle speed. For the following discussion, the parameters a and b may be either positive, for exponentially decreasing cross sections, or negative, for exponentially increasing cross sections. For most time-dependent Monte Carlo applications, the time and spatial variations of the cross-section data are handled by means of a stepwise procedure, holding the cross sections constant for each region over a small time interval Δt, performing the Monte Carlo random walk over the interval Δt, updating the cross sections, and then repeating for a series of time intervals. Continuously varying spatial- or time-dependent cross sections can be treated in a rigorous Monte Carlo fashion using delta-tracking, but inefficiencies may arise if the range of cross-section variation is large. In this paper, we present a new method for sampling collision distances directly for cross sections that vary exponentially in space or time. The method is exact and efficient and has direct application to Monte Carlo radiation transport methods. To verify that the probability density function (PDF) is correct and that the random-sampling procedure yields correct results, numerical experiments were performed using a one-dimensional Monte Carlo code. The physical problem consisted of a beam source impinging on a purely absorbing infinite slab, with a slab thickness of 1 cm and Σ 0 = 1 cm -1 . Monte Carlo calculations with 10 000 particles were run for a range of the exponential parameter b from -5 to +20 cm -1 . Two separate Monte Carlo calculations were run for each choice of b, a continuously varying case using the random-sampling procedures described earlier, and a 'conventional' case where the
9. Ecological change points: The strength of density dependence and the loss of history.
Science.gov (United States)
Ponciano, José M; Taper, Mark L; Dennis, Brian
2018-05-01
Change points in the dynamics of animal abundances have extensively been recorded in historical time series records. Little attention has been paid to the theoretical dynamic consequences of such change-points. Here we propose a change-point model of stochastic population dynamics. This investigation embodies a shift of attention from the problem of detecting when a change will occur, to another non-trivial puzzle: using ecological theory to understand and predict the post-breakpoint behavior of the population dynamics. The proposed model and the explicit expressions derived here predict and quantify how density dependence modulates the influence of the pre-breakpoint parameters into the post-breakpoint dynamics. Time series transitioning from one stationary distribution to another contain information about where the process was before the change-point, where is it heading and how long it will take to transition, and here this information is explicitly stated. Importantly, our results provide a direct connection of the strength of density dependence with theoretical properties of dynamic systems, such as the concept of resilience. Finally, we illustrate how to harness such information through maximum likelihood estimation for state-space models, and test the model robustness to widely different forms of compensatory dynamics. The model can be used to estimate important quantities in the theory and practice of population recovery. Copyright © 2018 Elsevier Inc. All rights reserved.
10. Delay-Range-Dependent H∞ Control for Automatic Mooring Positioning System with Time-Varying Input Delay
Directory of Open Access Journals (Sweden)
Xiaoyu Su
2014-01-01
Full Text Available Aiming at the economy and security of the positioning system in semi-submersible platform, the paper presents a new scheme based on the mooring line switching strategy. Considering the input delay in switching process, H∞ control with time-varying input delay is designed to calculate the control forces to resist disturbing forces. In order to reduce the conservativeness, the information of the lower bound of delay is taken into account, and a Lyapunov function which contains the range of delay is constructed. Besides, the input constraint is considered to avoid breakage of mooring lines. The sufficient conditions for delay-range-dependent stabilization are derived in terms of LMI, and the controller is also obtained. The effectiveness of the proposed approach is illustrated by a realistic design example.
11. Magnetic-Field Dependence of Raman Coupling Strength in Ultracold "4"0K Atomic Fermi Gas
International Nuclear Information System (INIS)
Huang Liang-Hui; Wang Peng-Jun; Meng Zeng-Ming; Peng Peng; Chen Liang-Chao; Li Dong-Hao; Zhang Jing
2016-01-01
We experimentally demonstrate the relation of Raman coupling strength with the external bias magnetic field in degenerate Fermi gas of "4"0K atoms. Two Raman lasers couple two Zeeman energy levels, whose energy splitting depends on the external bias magnetic field. The Raman coupling strength is determined by measuring the Rabi oscillation frequency. The characteristics of the Rabi oscillation is to be damped after several periods due to Fermi atoms in different momentum states oscillating with different Rabi frequencies. The experimental results show that the Raman coupling strength will decrease as the external bias magnetic field increases, which is in good agreement with the theoretical prediction. (paper)
12. State-dependent differential Riccati equation to track control of time-varying systems with state and control nonlinearities.
Science.gov (United States)
Korayem, M H; Nekoo, S R
2015-07-01
This work studies an optimal control problem using the state-dependent Riccati equation (SDRE) in differential form to track for time-varying systems with state and control nonlinearities. The trajectory tracking structure provides two nonlinear differential equations: the state-dependent differential Riccati equation (SDDRE) and the feed-forward differential equation. The independence of the governing equations and stability of the controller are proven along the trajectory using the Lyapunov approach. Backward integration (BI) is capable of solving the equations as a numerical solution; however, the forward solution methods require the closed-form solution to fulfill the task. A closed-form solution is introduced for SDDRE, but the feed-forward differential equation has not yet been obtained. Different ways of solving the problem are expressed and analyzed. These include BI, closed-form solution with corrective assumption, approximate solution, and forward integration. Application of the tracking problem is investigated to control robotic manipulators possessing rigid or flexible joints. The intention is to release a general program for automatic implementation of an SDDRE controller for any manipulator that obeys the Denavit-Hartenberg (D-H) principle when only D-H parameters are received as input data. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.
13. Temperature-dependent residual shear strength characteristics of smectite-rich landslide soils
Science.gov (United States)
Shibasaki, Tatsuya; Matsuura, Sumio; Okamoto, Takashi
2015-04-01
behaviors were also recognized during cooling-event tests. Shear stress fluctuations, which were obtained by 1 Hz data sampling, showed that shear behavior characteristically changed in response to temperature conditions. Stick-slip behavior prevailed under room temperature conditions, whereas shear behavior gradually changed into stable sliding behavior as temperature decreased. SEM (Scanning Electric Microscope) observation on shear surfaces indicated that silt- and sand-size asperities in the vicinity of the shear surface influence the occurrence of stick-slip behavior. It is also characteristically noted that rod-shaped smectitic clays, here called "roll", developed on shear surfaces and are arrayed densely perpendicular to the shearing direction in a micrometer scale. We assume that these rolls are probably rotating slowly within shear zone and acting as a lubricant which affects the temperature-dependent frictional properties of the shearing plane. These experimental results show that residual strength characteristics of smectite-rich soils are sensitive to temperature conditions. Our findings imply that if slip surface soils contain a high fraction of smectite, a decrease in ground temperature can lead to lowered shear resistance of the slip surface and triggering of slow landslide movement.
14. Dependence of compressive strength of green compacts on pressure, density and contact area of powder particles
International Nuclear Information System (INIS)
Salam, A.; Akram, M.; Shahid, K.A.; Javed, M.; Zaidi, S.M.
1994-08-01
The relationship between green compressive strength and compacting pressure as well as green density has been investigated for uniaxially pressed aluminium powder compacts in the range 0 - 520 MPa. Two linear relationships occurred between compacting pressure and green compressive strength which corresponded to powder compaction stages II and III respectively, increase in strength being large during stage II and quite small in stage III with increasing pressure. On the basis of both, the experimental results and a previous model on cold compaction of powder particles, relationships between green compressive strength and green density and interparticle contact area of the compacts has been established. (author) 9 figs
15. Is the relationship between increased knee muscle strength and improved physical function following exercise dependent on baseline physical function status?
Science.gov (United States)
Hall, Michelle; Hinman, Rana S; van der Esch, Martin; van der Leeden, Marike; Kasza, Jessica; Wrigley, Tim V; Metcalf, Ben R; Dobson, Fiona; Bennell, Kim L
2017-12-08
Clinical guidelines recommend knee muscle strengthening exercises to improve physical function. However, the amount of knee muscle strength increase needed for clinically relevant improvements in physical function is unclear. Understanding how much increase in knee muscle strength is associated with improved physical function could assist clinicians in providing appropriate strength gain targets for their patients in order to optimise outcomes from exercise. The aim of this study was to investigate whether an increase in knee muscle strength is associated with improved self-reported physical function following exercise; and whether the relationship differs according to physical function status at baseline. Data from 100 participants with medial knee osteoarthritis enrolled in a 12-week randomised controlled trial comparing neuromuscular exercise to quadriceps strengthening exercise were pooled. Participants were categorised as having mild, moderate or severe physical dysfunction at baseline using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Associations between 12-week changes in physical function (dependent variable) and peak isometric knee extensor and flexor strength (independent variables) were evaluated with and without accounting for baseline physical function status and covariates using linear regression models. In covariate-adjusted models without accounting for baseline physical function, every 1-unit (Nm/kg) increase in knee extensor strength was associated with physical function improvement of 17 WOMAC units (95% confidence interval (CI) -29 to -5). When accounting for baseline severity of physical function, every 1-unit increase in knee extensor strength was associated with physical function improvement of 24 WOMAC units (95% CI -42 to -7) in participants with severe physical dysfunction. There were no associations between change in strength and change in physical function in participants with mild or moderate physical
16. An MHD simulation model of time-dependent global solar corona with temporally varying solar-surface magnetic field maps
Science.gov (United States)
Hayashi, K.
2013-11-01
We present a model of a time-dependent three-dimensional magnetohydrodynamics simulation of the sub-Alfvenic solar corona and super-Alfvenic solar wind with temporally varying solar-surface boundary magnetic field data. To (i) accommodate observational data with a somewhat arbitrarily evolving solar photospheric magnetic field as the boundary value and (ii) keep the divergence-free condition, we developed a boundary model, here named Confined Differential Potential Field model, that calculates the horizontal components of the magnetic field, from changes in the vertical component, as a potential field confined in a thin shell. The projected normal characteristic method robustly simulates the solar corona and solar wind, in response to the temporal variation of the boundary Br. We conduct test MHD simulations for two periods, from Carrington Rotation number 2009 to 2010 and from Carrington Rotation 2074 to 2075 at solar maximum and minimum of Cycle 23, respectively. We obtained several coronal features that a fixed boundary condition cannot yield, such as twisted magnetic field lines at the lower corona and the transition from an open-field coronal hole to a closed-field streamer. We also obtained slight improvements of the interplanetary magnetic field, including the latitudinal component, at Earth.
17. Marriage is a dependent risk factor for mortality of colon adenocarcinoma without a time-varying effect.
Science.gov (United States)
Liu, Minling; Li, Lixian; Yu, Wei; Chen, Jie; Xiong, Weibin; Chen, Shuang; Yu, Li
2017-03-21
It has been well recognized that the effects of many prognostic factors could change during long-term follow-up. Although marriage has been proven to be a significant prognostic factor for the survival of colon cancer, whether the effect of marriage is constant with time remain unknown. This study analyzed the impact of marital status on the mortality of colon cancer patients with an extended Cox model that allowed for time-varying effects. We identified 71,955 patients who underwent colectomy between 2004 and 2009 to treat colon adenocarcinoma from the Surveilance, Epidemiology and End Results Database. The multivariate extended Cox model was used to evaluate the effect of marital status on all-cause mortality, while the Fine-Gray competing risks model was used for colon cancer-specific mortality, with death from other causes as the competing risk. The unmarried patients carried a 1.37-fold increased risk of all-cause mortality compared with the married patients (95%CI: 1.33-1.40; pMarriage is a dependent prognosis factor for survival of surgically treated colon adenocarcinoma patients. Psychological interventions are suggested to improve receipt of treatment among unmarried patients, as their poor survival may be due to the inefficient treatment.
18. Solubility product of tetravalent neptunium hydrous oxide and its ionic strength dependence
Energy Technology Data Exchange (ETDEWEB)
Fujiwara, K.; Mori, T. [Japan Nuclear Cycle Development Institute (JNC), 4-33, Muramatsu, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1194 (Japan); Kohara, Y. [Inspection and Development Company, 4-33, Muramatsu, Tokaimura, Naka-gun, Ibaraki-ken, 319-1112 (Japan)
2005-07-01
Full text of publication follows: Solubility products (K{sub sp}) are key parameters in the context of reliable assessment of actinides migration in the repository conditions of high level radioactive waste. Neptunium (Np(IV)) is one of the most important actinide elements in the assessment, because of its inventory and the long half-life. A few previous data for Np(IV) solubility are varied widely due to experimental difficulties related to the extremely low solubility. We carried out batch-type experiments under nitrogen atmosphere using a glovebox. Np(V) was reduced to Np(III) by bubbling 0.5 ppm H{sub 2} / N{sub 2} gas through the solution for 30 days in the presence of platinum black as catalyst. After reducing treatment, the Np(III) converted to Np(IV) by auto-oxidation within approximately three days. The solubilities of the Np(IV) were measured in the pHc ranging from 2 to 4, at room temperature (23 {+-} 2 deg. C), in ionic strength(I) = 0.1, 0.5, 1.0 and 2.0 M NaClO{sub 4}. The equilibrium condition was confirmed by over-saturation and under-saturation method. After the equilibrium, the pH{sub c} and the E{sub h} value of the suspension were measured. The suspension was then filtered using a filter with a NMWL of 3000 (less than 2 nm{phi}). The Np radio activity in the filtrate was determined by alpha spectrometry and absorption spectra of Np(IV). The solubility decreased with increasing pHc and the hydrolysis species are predominantly formed. From the obtained results, the solubility products (K{sub sp}) of Np hydroxide, for the reaction, NpO{sub 2} . xH{sub 2}O {r_reversible} Np{sup 4+} + 4OH{sup -} + (x-2)H{sub 2}O, at I = 0.1, 0.5, 1.0 and 2.0 were determined by using formation constants ({beta}{sub n}(I)), which were determined for the reaction, Np{sup 4+} + nOH{sup -} {r_reversible} Np(OH){sub n}{sup (4-n)+}. By using the specific interaction theory (SIT), the solubility product of tetravalent Np hydrous oxide is calculated to be log K{sub sp}{sup 0
19. Child Mortality, Women's Status, Economic Dependency, and State Strength: A Cross-National Study of Less Developed Countries.
Science.gov (United States)
Shen, Ce; Williamson, John B.
1997-01-01
Data from 86 developing countries suggest that foreign investment and debt dependency have adverse indirect effects on child mortality--effects mediated by variables linked to industrialism theory and gender stratification theory: women's education, health, and reproductive autonomy and rate of economic growth. State strength was related to lower…
20. On Regularly Varying and History-Dependent Convergence Rates of Solutions of a Volterra Equation with Infinite Memory
OpenAIRE
John A. D. Appleby
2010-01-01
We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. ...
1. Ionic strength dependence of the oxidation of SO2 by H2O2 in sodium chloride particles
Science.gov (United States)
Ali, H. M.; Iedema, M.; Yu, X.-Y.; Cowin, J. P.
2014-06-01
The reaction of sulfur dioxide and hydrogen peroxide in the presence of deliquesced (>75% RH) sodium chloride (brine) particles was studied by utilizing a cross flow mini-reactor. The reaction kinetics were followed by observing chloride depletion in particles by computer-controlled scanning electron microscope with energy dispersive X-ray analysis, namely CCSEM/EDX. The reactions take place in concentrated mixed salt brine aerosols, for which no complete kinetic equilibrium data previously existed. We measured the Henry's law solubility of H2O2 in brine solutions to close that gap. We also calculated the reaction rate as the particle transforms continuously from concentrated NaCl brine to, eventually, a mixed NaHSO4 plus H2SO4 brine solution. The reaction rate of the SO2 oxidation by H2O2 was found to be influenced by the change in ionic strength as the particle undergoes compositional transformation, following closely the dependence of the third order rate constant on ionic strength as predicted using established rate equations. This is the first study that has measured the ionic strength dependence of sulfate formation (in non-aqueous media) from oxidation of mixed salt brine aerosols in the presence of H2O2. It also gives the first report of the dependence of the Henry's law constant of H2O2 on ionic strength.
2. Adhesive Strength of dry Adhesive Structures Depending on the Thickness of Metal Coating
Energy Technology Data Exchange (ETDEWEB)
Kim, Gyu Hye; Kwon, Da Som; Kim, Mi Jung; Kim, Su Hee; Yoon, Ji Won; An, Tea Chang; Hwang, Hui Yun [Andong National Univ., Andong (Korea, Republic of)
2016-07-15
Recently, engineering applications have started to adopt solutions inspired by nature. The peculiar adhesive properties of gecko skin are an example, as they allow the animal to move freely on vertical walls and even on ceilings. The high adhesive forces between gecko feet and walls are due to the hierarchical microscopical structure of the skin. In this study, the effect of metal coatings on the adhesive strength of synthetic, hierarchically structured, dry adhesives was investigated. Synthetic dry adhesives were fabricated using PDMS micro-molds prepared by photolithography. Metal coatings on synthetic dry adhesives were formed by plasma sputtering. Adhesive strength was measured by pure shear tests. The highest adhesion strengths were found with coatings composed of 4 nm thick layers of Indium, 8 nm thick layers of Zinc and 6 nm thick layers of Gold, respectively.
3. Adhesive Strength of dry Adhesive Structures Depending on the Thickness of Metal Coating
International Nuclear Information System (INIS)
Kim, Gyu Hye; Kwon, Da Som; Kim, Mi Jung; Kim, Su Hee; Yoon, Ji Won; An, Tea Chang; Hwang, Hui Yun
2016-01-01
Recently, engineering applications have started to adopt solutions inspired by nature. The peculiar adhesive properties of gecko skin are an example, as they allow the animal to move freely on vertical walls and even on ceilings. The high adhesive forces between gecko feet and walls are due to the hierarchical microscopical structure of the skin. In this study, the effect of metal coatings on the adhesive strength of synthetic, hierarchically structured, dry adhesives was investigated. Synthetic dry adhesives were fabricated using PDMS micro-molds prepared by photolithography. Metal coatings on synthetic dry adhesives were formed by plasma sputtering. Adhesive strength was measured by pure shear tests. The highest adhesion strengths were found with coatings composed of 4 nm thick layers of Indium, 8 nm thick layers of Zinc and 6 nm thick layers of Gold, respectively
4. Stereotype Strength and Attentional Bias: Preference for Confirming versus Disconfirming Information Depends on Processing Capacity
Science.gov (United States)
Allen, Thomas J.; Sherman, Jeffrey W.; Conrey, Frederica R.; Stroessner, Steven J.
2009-01-01
In two experiments, we investigated the relationships among stereotype strength, processing capacity, and the allocation of attention to stereotype-consistent versus stereotype-inconsistent information describing a target person. The results of both experiments showed that, with full capacity, greater stereotype strength was associated with increased attention toward stereotype-consistent versus stereotype-inconsistent information. However, when capacity was diminished, greater stereotype strength was associated with increased attention toward inconsistent versus consistent information. Thus, strong stereotypes may act as self-confirming filters when processing capacity is plentiful, but as efficient information gathering devices that maximize the acquisition of novel (disconfirming) information when capacity is depleted. Implications for models of stereotyping and stereotype change are discussed. PMID:20161043
5. On Regularly Varying and History-Dependent Convergence Rates of Solutions of a Volterra Equation with Infinite Memory
Directory of Open Access Journals (Sweden)
2010-01-01
Full Text Available We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. The result is considered both for a linear Volterra integrodifferential equation as well as for the delay logistic equation from population biology.
6. Time-Dependent Stress Rupture Strength Degradation of Hi-Nicalon Fiber-Reinforced Silicon Carbide Composites at Intermediate Temperatures
Science.gov (United States)
Sullivan, Roy M.
2016-01-01
The stress rupture strength of silicon carbide fiber-reinforced silicon carbide composites with a boron nitride fiber coating decreases with time within the intermediate temperature range of 700 to 950 degree Celsius. Various theories have been proposed to explain the cause of the time-dependent stress rupture strength. The objective of this paper is to investigate the relative significance of the various theories for the time-dependent strength of silicon carbide fiber-reinforced silicon carbide composites. This is achieved through the development of a numerically based progressive failure analysis routine and through the application of the routine to simulate the composite stress rupture tests. The progressive failure routine is a time-marching routine with an iterative loop between a probability of fiber survival equation and a force equilibrium equation within each time step. Failure of the composite is assumed to initiate near a matrix crack and the progression of fiber failures occurs by global load sharing. The probability of survival equation is derived from consideration of the strength of ceramic fibers with randomly occurring and slow growing flaws as well as the mechanical interaction between the fibers and matrix near a matrix crack. The force equilibrium equation follows from the global load sharing presumption. The results of progressive failure analyses of the composite tests suggest that the relationship between time and stress-rupture strength is attributed almost entirely to the slow flaw growth within the fibers. Although other mechanisms may be present, they appear to have only a minor influence on the observed time-dependent behavior.
7. Span-Dependent Distributions of the Bending Strength of Spruce Timber
DEFF Research Database (Denmark)
Ditlevsen, Ove; Källsner, Bo
2005-01-01
Tests data of bending strengths of a large number of timber beams of different spans obtained at the Swedish Institute for Wood Technology Research reveal a statistical structure that can be represented in a simple probabilistic model of series system type. A particular feature of the data from one...
8. Target strength of some European fish species and its dependence on fish body parameters
Czech Academy of Sciences Publication Activity Database
Frouzová, Jaroslava; Kubečka, Jan; Balk, H.; Frouz, Jan
2005-01-01
Roč. 75, 1-3 (2005), s. 86-96 ISSN 0165-7836 R&D Projects: GA AV ČR(CZ) IBS6017004 Institutional research plan: CEZ:AV0Z6017912 Keywords : target strength * freshwater fish * acoustics Subject RIV: EH - Ecology, Behaviour Impact factor: 1.160, year: 2005
9. Analysis of Environmental Impact for Concrete Using LCA by Varying the Recycling Components, the Compressive Strength and the Admixture Material Mixing
Directory of Open Access Journals (Sweden)
Taehyoung Kim
2016-04-01
10. Healing of shear strength and its time dependency in a single rock fracture
International Nuclear Information System (INIS)
Kawaguchi, Yuta; Nakashima, Shinichiro; Yasuhara, Hideaki; Kishida, Kiyoshi
2011-01-01
Evolution of the long-term mechanical, hydraulic, and transport characteristics of rock fractures should be, in advance, predicted in considering an issue on entombment of energy byproducts of high level radioactive wastes. Under stressed and temperature conditions, those behaviors of the rock fractures of interest may be evolved in time and space likely due to the change in topographical aperture distributions. This irreversible process may be induced by pure mechanical and/or chemo-mechanical creeps such as water-rock reactions like stress corrosion and pressure solution, and chemical effects including mineral dissolution and reprecipitation in the free-walls of fractures. Specifically, the chemo-mechanical processes active at the contacting asperities within rock fractures may exert a significant influence on the mechanical, hydraulic, and transport behaviors throughout a long period, and thus, should be vigorously examined theoretically and experimentally. This paper presents the slide-hold-slide shear test results for fully saturated, single-jointed mortar specimens so as to investigate the effects of load holding on mechanical properties of rock joints. From the test results, it was confirmed that shear strength increased for mortar specimens in both short and long time holding cases. However, the evolution of shear strength recovery in two cases is different. This is because a dominant factor of shear strength recovery during the short time holding may be attributed to a pure mechanical process like creep deformation at contacting asperities, while the one during long time holding is affected by both mechanical and chemical processes like pressure solution. Moreover, to reproduce the shear strength recovery during short time holding we develop a direct shear model by including temporal variation of dilation during holding. The model predictions are in relatively good agreement with the test measurements. (author)
11. Density-dependent seedling mortality varies with light availability and species abundance in wet and dry Hawaiian forests
Science.gov (United States)
Faith Inman-Narahari; Rebecca Ostertag; Stephen P. Hubbell; Christian P. Giardina; Susan Cordell; Lawren Sack; Andrew MacDougall
2016-01-01
Conspecific density may contribute to patterns of species assembly through negative density dependence (NDD) as predicted by the Janzen-Connell hypothesis, or through facilitation (positive density dependence; PDD). Conspecific density effects are expected to be more negative in darker and wetter environments due to higher pathogen abundance and...
12. Three-dimensional orientation and location-dependent varying rules of radiographic angles of the acetabular cup.
Science.gov (United States)
Zhao, Jing-Xin; Su, Xiu-Yun; Zhao, Zhe; Xiao, Ruo-Xiu; Zhang, Li-Cheng; Tang, Pei-Fu
2018-02-17
The aim of this study is to demonstrate the varying rules of radiographic angles following varying three-dimensional (3D) orientations and locations of cup using an accurate mathematical model. A cone model is established to address the quantitative relationship between the opening circle of cup and its ellipse projection on radiograph. The varying rules of two-dimensional (2D) radiographic anteversion (RA) and inclination (RI) angles can be analyzed. When the centre of cup is located above X-ray source, with proper 3D RI/RA angles, 2D RA angle can be equal to its 3D counterpart, and 2D RI angle is usually greater than its 3D counterpart. Except for the original point on hip-centered anterior-posterior radiograph, there is no area on radiograph where both 2D RA and RI angles are equal to their 3D counterparts simultaneously. This study proposes an innovative model for accurately explaining how 2D RA/RI angles of cup are varying following different 3D RA/RI angles and location of cup. The analysis results provide clinicians an intuitive grasp of knowledge about 2D RA/RI angles greater or smaller than their 3D counterparts post-operatively. The established model may allow determining the effects of pelvic rotations on 2D radiographic angles of cup.
13. The effects of boron supplementation of layer diets varying in calcium and phosphorus concentrations on performance, egg quality, bone strength and mineral constituents of serum, bone and faeces.
Science.gov (United States)
Küçükyilmaz, K; Erkek, R; Bozkurt, M
2014-01-01
1. A 2 × 3 factorial arrangement of treatments was used to investigate the effects of dietary calcium (Ca), phosphorus (P), and supplemental boron (B) (0, 75, and 150 mg/kg) on the performance, egg quality, bone strength, and mineral constituents in bone, serum and faeces. 2. A reduction by 18% in the dietary Ca-P concentration from the recommended levels for the hen strain reduced (P properties did not corroborate the hypothesis that B is a trace element playing an important role in mineral metabolism and bone strength through an interaction with Ca, P and Mg.
14. Delay-Dependent Stability Criterion for Bidirectional Associative Memory Neural Networks with Interval Time-Varying Delays
Science.gov (United States)
Park, Ju H.; Kwon, O. M.
In the letter, the global asymptotic stability of bidirectional associative memory (BAM) neural networks with delays is investigated. The delay is assumed to be time-varying and belongs to a given interval. A novel stability criterion for the stability is presented based on the Lyapunov method. The criterion is represented in terms of linear matrix inequality (LMI), which can be solved easily by various optimization algorithms. Two numerical examples are illustrated to show the effectiveness of our new result.
15. Effect of dislocation pile-up on size-dependent yield strength in finite single-crystal micro-samples
Energy Technology Data Exchange (ETDEWEB)
Pan, Bo; Shibutani, Yoji, E-mail: [email protected] [Department of Mechanical Engineering, Osaka University, Suita 565-0871 (Japan); Zhang, Xu [State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi' an Jiaotong University, Xi' an 710049 (China); School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou 450001 (China); Shang, Fulin [State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi' an Jiaotong University, Xi' an 710049 (China)
2015-07-07
Recent research has explained that the steeply increasing yield strength in metals depends on decreasing sample size. In this work, we derive a statistical physical model of the yield strength of finite single-crystal micro-pillars that depends on single-ended dislocation pile-up inside the micro-pillars. We show that this size effect can be explained almost completely by considering the stochastic lengths of the dislocation source and the dislocation pile-up length in the single-crystal micro-pillars. The Hall–Petch-type relation holds even in a microscale single-crystal, which is characterized by its dislocation source lengths. Our quantitative conclusions suggest that the number of dislocation sources and pile-ups are significant factors for the size effect. They also indicate that starvation of dislocation sources is another reason for the size effect. Moreover, we investigated the explicit relationship between the stacking fault energy and the dislocation “pile-up” effect inside the sample: materials with low stacking fault energy exhibit an obvious dislocation pile-up effect. Our proposed physical model predicts a sample strength that agrees well with experimental data, and our model can give a more precise prediction than the current single arm source model, especially for materials with low stacking fault energy.
16. Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength.
Science.gov (United States)
Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W
2008-02-21
Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems.
17. Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength
International Nuclear Information System (INIS)
Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W
2008-01-01
Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems
18. New Delay-Dependent Robust Exponential Stability Criteria of LPD Neutral Systems with Mixed Time-Varying Delays and Nonlinear Perturbations
Directory of Open Access Journals (Sweden)
2013-01-01
Full Text Available This paper is concerned with the problem of robust exponential stability for linear parameter-dependent (LPD neutral systems with mixed time-varying delays and nonlinear perturbations. Based on a new parameter-dependent Lyapunov-Krasovskii functional, Leibniz-Newton formula, decomposition technique of coefficient matrix, free-weighting matrices, Cauchy’s inequality, modified version of Jensen’s inequality, model transformation, and linear matrix inequality technique, new delay-dependent robust exponential stability criteria are established in terms of linear matrix inequalities (LMIs. Numerical examples are given to show the effectiveness and less conservativeness of the proposed methods.
19. Compressive strength and resistance to chloride ion penetration and carbonation of recycled aggregate concrete with varying amount of fly ash and fine recycled aggregate.
Science.gov (United States)
Sim, Jongsung; Park, Cheolwoo
2011-11-01
Construction and demolition waste has been dramatically increased in the last decade, and social and environmental concerns on the recycling have consequently been increased. Recent technology has greatly improved the recycling process for waste concrete. This study investigates the fundamental characteristics of concrete using recycled concrete aggregate (RCA) for its application to structural concrete members. The specimens used 100% coarse RCA, various replacement levels of natural aggregate with fine RCA, and several levels of fly ash addition. Compressive strength of mortar and concrete which used RCA gradually decreased as the amount of the recycled materials increased. Regardless of curing conditions and fly ash addition, the 28 days strength of the recycled aggregate concrete was greater than the design strength, 40 MPa, with a complete replacement of coarse aggregate and a replacement level of natural fine aggregate by fine RCA up to 60%. The recycled aggregate concrete achieved sufficient resistance to the chloride ion penetration. The measured carbonation depth did not indicate a clear relationship to the fine RCA replacement ratio but the recycled aggregate concrete could also attain adequate carbonation resistance. Based on the results from the experimental investigations, it is believed that the recycled aggregate concrete can be successfully applied to structural concrete members. Copyright © 2011 Elsevier Ltd. All rights reserved.
20. Isotopic dependences of the dielectric strength of gases: new observations, classification, and possible origins
International Nuclear Information System (INIS)
Christophorou, L.G.; Rodrigo, H.; Marode, E.; Bastien, F.
1985-01-01
In this paper we report: (1) the finding that the CH 4 /CD 4 nonuniform field behavior is polarity dependent (i.e., the V/sub s/ of CD 4 is lower than the V/sub s/ of CH 4 for negative polarity which is just the opposite of that observed for positive polarity); (2) discuss the origins of the observed isotope effects and predict new isotopic dependences of V/sub s/; and (3) report results on the V/sub s/ of H 2 S and D 2 S for negative polarity which confirm their predicted isotopic behavior
1. Polarized Line Formation in Arbitrary Strength Magnetic Fields Angle-averaged and Angle-dependent Partial Frequency Redistribution
Energy Technology Data Exchange (ETDEWEB)
Sampoorna, M.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, Bengaluru 560 034 (India); Stenflo, J. O., E-mail: [email protected], E-mail: [email protected], E-mail: [email protected] [Institute of Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland)
2017-08-01
Magnetic fields in the solar atmosphere leave their fingerprints in the polarized spectrum of the Sun via the Hanle and Zeeman effects. While the Hanle and Zeeman effects dominate, respectively, in the weak and strong field regimes, both these effects jointly operate in the intermediate field strength regime. Therefore, it is necessary to solve the polarized line transfer equation, including the combined influence of Hanle and Zeeman effects. Furthermore, it is required to take into account the effects of partial frequency redistribution (PRD) in scattering when dealing with strong chromospheric lines with broad damping wings. In this paper, we present a numerical method to solve the problem of polarized PRD line formation in magnetic fields of arbitrary strength and orientation. This numerical method is based on the concept of operator perturbation. For our studies, we consider a two-level atom model without hyperfine structure and lower-level polarization. We compare the PRD idealization of angle-averaged Hanle–Zeeman redistribution matrices with the full treatment of angle-dependent PRD, to indicate when the idealized treatment is inadequate and what kind of polarization effects are specific to angle-dependent PRD. Because the angle-dependent treatment is presently computationally prohibitive when applied to realistic model atmospheres, we present the computed emergent Stokes profiles for a range of magnetic fields, with the assumption of an isothermal one-dimensional medium.
2. Is inertial flywheel resistance training superior to gravity-dependent resistance training in improving muscle strength?
DEFF Research Database (Denmark)
Vicens-Bordas, J; Esteve, E; Fort-Vanmeerhaeghe, A
2018-01-01
-dependent resistance training in improving other muscular adaptations. DESIGN: A systematic review with meta-analyses of randomised and non-randomised controlled trials. METHODS: We searched MEDLINE, Scopus, SPORTDiscus, Web of Science and Cochrane Central Register of Controlled Trials with no publication date...
3. Dependence of streamer density on electric field strength on positive electrode
Science.gov (United States)
Koki, Nakamura; Takahumi, Okuyama; Wang, Douyan; Takao, N.; Hidenori, Akiyama; Kumamoto University Collaboration
2015-09-01
Pulsed streamer discharge plasma, a type of non-thermal plasma, is known as generation method of reactive radicals and ozone and treatment of exhausted gas. From our previous research, the distance between electrodes has been considered a very important parameter for applications using pulsed streamer discharge. However, how the distance between electrodes affects the pulsed discharge hasn't been clarified. In this research, the propagation process of pulsed streamer discharge in a wire-plate electrode was observed using an ICCD camera for 4 electrodes having different distance between electrodes. The distance between electrodes was changeable at 45 mm, 40 mm, 35 mm, and 30 mm. The results show that, when the distance between electrodes was shortened, applied voltage with a pulse duration of 100 ns decreased from 80 to 60.3 kV. Conversely, discharge current increased from 149 to 190 A. Streamer head velocity became faster. On the other hand, Streamer head density at onset time of streamer head propagation didn't change. This is considered due to the electric field strength of streamer head at that time, in result, it was about 14 kV/mm under each distance between electrodes.
4. Pressure-dependent electron attachment and breakdown strengths of unitary gases, and synergism of binary gas mixtures: a relationship
International Nuclear Information System (INIS)
Hunter, S.R.; Christophorou, L.G.
1984-04-01
The relationship between the pressure-dependent electron attachment rate constants (k/sub a/) which have been observed in 1-C 3 F 6 and in several perfluoroalkanes, and the uniform field breakdown strengths (E/N)/sub lim/ in these gases is discussed. Measurements of the pressure dependence of k/sub a/ of OCS in a buffer gas of Ar are presented and the possible pressure dependence of (E/N)/sub lim/ in OCS is discussed. Uniform field breakdown measurements have been performed in C 3 F 8 , n-C 4 F 10 , and SO 2 over a range of gas pressures (3 less than or equal to P/sub T/ less than or equal to 290 kPa) and are reported. All three molecules have been found to possess pressure-dependent (E/N)/sub lim/ values. The various types of synergistic behavior which have been observed in binary gas dielectric mixtures are summarized and discussed. A new mechanism is outlined which can explain the synergism observed in several gas mixtures where the (E/N)/sub lim/ values of the mixutres are greater than those of the individual gas constituents. Model calculations are presented which support this mechanism, and can be used to explain the pressure-dependent synergistic effects which have been reported in 1-C 3 F 6 /SF 6 gas mixture
5. Microstructural effects on the yield strength and its temperature dependence in a bainitic precipitation hardened Cr-Mo-V steel
International Nuclear Information System (INIS)
Toerroenen, K.; Kotilainen, H.; Nenonen, P.
1980-03-01
The plastic deformation behaviour of a precipitation hardened bainitic Cr-Mo-V steel is analyzed at ambient and low temperatures. The temperature dependent component of the yield strength is composed of the Peierls-Nabarro force and also partly of the strengthening contribution of the lath- and cell boundaries or the solid solution hardening. The temperature dependence below 230 K is in accordance with the models presented by Yanoshevich and Ryvkina as well as Dorn and Rajnak. The temperature independent component can be calculated merely from the dislocation density, which is stabilized by the vanadium-rich carbides. The linear additivity cannot be used for the superposition of the strengthening effects of various strengthening parameters, By using the phenomenological approach starting from the dislocation movement mechanisms upon yielding the laws for the superposition are discussed. (author)
6. Computer-aided model analysis for ionic strength-dependent effective charge of protein in ion-exchange chromatography
DEFF Research Database (Denmark)
Lim, Young-il; Jørgensen, Sten Bay; Kim, In-Ho
2005-01-01
differential algebraic equation (PDAE) system, a fast and accurate numerical method (i.e., conservation element/solution element (CE/SE) method), is proposed. Sensitivity and elasticity of the model parameters (e.g., steric/shape factors, adsorption heat coefficient, effective protein charge, equilibrium...... constant, mass transfer coefficient, axial dispersion coefficient and bed voidage) are analyzed for a BSA-salt system in a low protein concentration range. Within a low concentration range of bovine serum albumin (BSA) where linear adsorption isotherms are shown, the adsorption heat coefficient, shape...... salt concentrations, it is proposed that the effective protein charge could depend upon the salt concentration (or ionic strength). The reason for this dependence may be a steric hindrance of protein binding sites combined with a salt shielding effect neutralizing the surface charges of the protein. (c...
7. Kinetics of the oxidation of hydrogen sulfite by hydrogen peroxide in aqueous solution:. ionic strength effects and temperature dependence
Science.gov (United States)
Maaß, Frank; Elias, Horst; Wannowius, Klaus J.
Conductometry was used to study the kinetics of the oxidation of hydrogen sulfite, HSO -3, by hydrogen peroxide in aqueous non-buffered solution at the low concentration level of 10 -5-10 -6 M, typically found in cloud water. The kinetic data confirm that the rate law reported for the pH range 3-6 at higher concentration levels, rate= kH·[H +]·[HSO -3]·[H 2O 2], is valid at the low concentration level and at low ionic strength Ic. At 298 K and Ic=1.5×10 -4 M, third-order rate constant kH was found to be kH=(9.1±0.5)×10 7 M -2 s -1. The temperature dependence of kH led to an activation energy of Ea=29.7±0.9 kJ mol -1. The effect of the ionic strength (adjusted with NaCl) on rate constant kH was studied in the range Ic=2×10 -4-5.0 M at pH=4.5-5.2 by conductometry and stopped-flow spectrophotometry. The dependence of kH on Ic can be described with a semi-empirical relationship, which is useful for the purpose of comparison and extrapolation. The kinetic data obtained are critically compared with those reported earlier.
8. Plant diversity increases with the strength of negative density dependence at the global scale
Science.gov (United States)
LaManna, Joseph A.; Mangan, Scott A.; Alonso, Alfonso; Bourg, Norman; Brockelman, Warren Y.; Bunyavejchewin, Sarayudh; Chang, Li-Wan; Chiang, Jyh-Min; Chuyong, George B.; Clay, Keith; Condit, Richard; Cordell, Susan; Davies, Stuart J.; Furniss, Tucker J.; Giardina, Christian P.; Gunatilleke, I.A.U. Nimal; Gunatilleke, C.V. Savitri; He, Fangliang; Howe, Robert W.; Hubbell, Stephen P.; Hsieh, Chang-Fu; Inman-Narahari, Faith M.; Janik, David; Johnson, Daniel J.; Kenfack, David; Korte, Lisa; Kral, Kamil; Larson, Andrew J.; Lutz, James A.; McMahon, Sean M.; McShea, William J.; Memiaghe, Herve R.; Nathalang, Anuttara; Novotny, Vojtech; Ong, Perry S.; Orwig, David A.; Ostertag, Rebecca; Parker, Geoffrey G.; Phillips, Richard P.; Sack, Lawren; Sun, I-Fang; Tello, J. Sebastian; Thomas, Duncan W.; Turner, Benjamin L.; Vela Diaz, Dilys M.; Vrska, Tomas; Weiblen, George D.; Wolf, Amy; Yap, Sandra; Myers, Jonathan A.
2017-01-01
Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.
9. Dependence of fluence errors in dynamic IMRT on leaf-positional errors varying with time and leaf number
International Nuclear Information System (INIS)
Zygmanski, Piotr; Kung, Jong H.; Jiang, Steve B.; Chin, Lee
2003-01-01
In d-MLC based IMRT, leaves move along a trajectory that lies within a user-defined tolerance (TOL) about the ideal trajectory specified in a d-MLC sequence file. The MLC controller measures leaf positions multiple times per second and corrects them if they deviate from ideal positions by a value greater than TOL. The magnitude of leaf-positional errors resulting from finite mechanical precision depends on the performance of the MLC motors executing leaf motions and is generally larger if leaves are forced to move at higher speeds. The maximum value of leaf-positional errors can be limited by decreasing TOL. However, due to the inherent time delay in the MLC controller, this may not happen at all times. Furthermore, decreasing the leaf tolerance results in a larger number of beam hold-offs, which, in turn leads, to a longer delivery time and, paradoxically, to higher chances of leaf-positional errors (≤TOL). On the other end, the magnitude of leaf-positional errors depends on the complexity of the fluence map to be delivered. Recently, it has been shown that it is possible to determine the actual distribution of leaf-positional errors either by the imaging of moving MLC apertures with a digital imager or by analysis of a MLC log file saved by a MLC controller. This leads next to an important question: What is the relation between the distribution of leaf-positional errors and fluence errors. In this work, we introduce an analytical method to determine this relation in dynamic IMRT delivery. We model MLC errors as Random-Leaf Positional (RLP) errors described by a truncated normal distribution defined by two characteristic parameters: a standard deviation σ and a cut-off value Δx 0 (Δx 0 ∼TOL). We quantify fluence errors for two cases: (i) Δx 0 >>σ (unrestricted normal distribution) and (ii) Δx 0 0 --limited normal distribution). We show that an average fluence error of an IMRT field is proportional to (i) σ/ALPO and (ii) Δx 0 /ALPO, respectively, where
10. T Cell Subset and Stimulation Strength-Dependent Modulation of T Cell Activation by Kv1.3 Blockers.
Directory of Open Access Journals (Sweden)
Wai-Ping Fung-Leung
Full Text Available Kv1.3 is a voltage-gated potassium channel expressed on T cells that plays an important role in T cell activation. Previous studies have shown that blocking Kv1.3 channels in human T cells during activation results in reduced calcium entry, cytokine production, and proliferation. The aim of the present study was to further explore the effects of Kv1.3 blockers on the response of different human T cell subsets under various stimulation conditions. Our studies show that, unlike the immune suppressor cyclosporine A, the inhibitory effect of Kv1.3 blockers was partial and stimulation strength dependent, with reduced inhibitory efficacy on T cells under strengthened anti-CD3/CD28 stimulations. T cell responses to allergens including house dust mites and ragweed were partially reduced by Kv1.3 blockers. The effect of Kv1.3 inhibition was dependent on T cell subsets, with stronger effects on CCR7- effector memory compared to CCR7+ central memory CD4 T cells. Calcium entry studies also revealed a population of CD4 T cells resistant to Kv1.3 blockade. Activation of CD4 T cells was accompanied with an increase in Kv1.3 currents but Kv1.3 transcripts were found to be reduced, suggesting a posttranscriptional mechanism in the regulation of Kv1.3 activities. In summary, Kv1.3 blockers inhibit T cell activation in a manner that is highly dependent on the T cell identity and stimulation strength, These findings suggest that Kv1.3 blockers inhibit T cells in a unique, conditional manner, further refining our understanding of the therapeutic potential of Kv1.3 blockers.
11. Methanol emissions from maize: Ontogenetic dependence to varying light conditions and guttation as an additional factor constraining the flux
Science.gov (United States)
Mozaffar, A.; Schoon, N.; Digrado, A.; Bachy, A.; Delaplace, P.; du Jardin, P.; Fauconnier, M.-L.; Aubinet, M.; Heinesch, B.; Amelynck, C.
2017-03-01
Because of its high abundance and long lifetime compared to other volatile organic compounds in the atmosphere, methanol (CH3OH) plays an important role in atmospheric chemistry. Even though agricultural crops are believed to be a large source of methanol, emission inventories from those crop ecosystems are still scarce and little information is available concerning the driving mechanisms for methanol production and emission at different developmental stages of the plants/leaves. This study focuses on methanol emissions from Zea mays L. (maize), which is vastly cultivated throughout the world. Flux measurements have been performed on young plants, almost fully grown leaves and fully grown leaves, enclosed in dynamic flow-through enclosures in a temperature and light-controlled environmental chamber. Strong differences in the response of methanol emissions to variations in PPFD (Photosynthetic Photon Flux Density) were noticed between the young plants, almost fully grown and fully grown leaves. Moreover, young maize plants showed strong emission peaks following light/dark transitions, for which guttation can be put forward as a hypothetical pathway. Young plants' average daily methanol fluxes exceeded by a factor of 17 those of almost fully grown and fully grown leaves when expressed per leaf area. Absolute flux values were found to be smaller than those reported in the literature, but in fair agreement with recent ecosystem scale flux measurements above a maize field of the same variety as used in this study. The flux measurements in the current study were used to evaluate the dynamic biogenic volatile organic compound (BVOC) emission model of Niinemets and Reichstein. The modelled and measured fluxes from almost fully grown leaves were found to agree best when a temperature and light dependent methanol production function was applied. However, this production function turned out not to be suitable for modelling the observed emissions from the young plants
12. Design, Synthesis, Structural and Spectroscopic Studies of Push-Pull Two-Photon Absorbing Chromophores with Acceptor Groups of Varying Strength
Science.gov (United States)
Morales, Alma R.; Frazer, Andrew; Woodward, Adam W.; Ahn-White, Hyo-Yang; Fonari, Alexandr; Tongwa, Paul; Timofeeva, Tatiana; Belfield, Kevin D.
2013-01-01
A new series of unsymmetrical diphenylaminofluorene-based chromophores with various strong π-electron acceptors were synthesized and fully characterized. The systematic alteration of the structural design facilitated the investigation of effects such as molecular symmetry and strength of electron-donating and/or withdrawing termini have on optical nonlinearity. In order to determine the electronic and geometrical properties of the novel compounds, a thorough investigation was carried out by a combination of linear and nonlinear spectroscopic techniques, single crystal X-ray diffraction, and quantum chemical calculations. Finally, on the basis of two-photon absorption (2PA) cross sections, the general trend for π -electron accepting ability, i.e., ability to accept charge transfer from diphenylamine was: 2-pyran-4-ylidene malononitrile (pyranone) > dicyanovinyl > bis(dicyanomethylidene)indane > 1-(thiophen-2-yl)propenone > dicyanoethylenyl > 3-(thiophen-2-yl)propenone. An analog with the 2-pyran-4-ylidene malononitrile acceptor group exhibited a nearly three-fold enhancement of the 2PA< δ (1650 GM at 840 nm), relative to other members of the series. PMID:23305555
13. Environmental conditions during breeding modify the strength of mass-dependent carry-over effects in a migratory bird.
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Xavier A Harrison
Full Text Available In many animals, processes occurring in one season carry over to influence reproductive success and survival in future seasons. The strength of such carry-over effects is unlikely to be uniform across years, yet our understanding of the processes that are capable of modifying their strength remains limited. Here we show that female light-bellied Brent geese with higher body mass prior to spring migration successfully reared more offspring during breeding, but only in years where environmental conditions during breeding were favourable. In years of bad weather during breeding, all birds suffered reduced reproductive output irrespective of pre-migration mass. Our results suggest that the magnitude of reproductive benefits gained by maximising body stores to fuel breeding fluctuates markedly among years in concert with conditions during the breeding season, as does the degree to which carry-over effects are capable of driving variance in reproductive success among individuals. Therefore while carry-over effects have considerable power to drive fitness asymmetries among individuals, our ability to interpret these effects in terms of their implications for population dynamics is dependent on knowledge of fitness determinants occurring in subsequent seasons.
14. Shear-rate-dependent strength control on the dynamics of rainfall-triggered landslides, Tokushima Prefecture, Japan
Science.gov (United States)
Wang, G.; Suemine, A.; Schulz, W.H.
2010-01-01
A typhoon (Typhoon No. 10) attacked Shikoku Island and the Tyugoku area of Japan in 2004. This typhoon produced a new daily precipitation record of 1317 mm on Shikoku Island and triggered hundreds of landslides in Tokushima Prefecture. One catastrophic landslide was triggered in the Shiraishi area of Kisawa village, and destroyed more than 10 houses while also leaving an unstable block high on the slope. The unstable block kept moving after the event, showing accelerating and decelerating movement during and after rainfall and reaching a displacement of several meters before countermeasures were put into place. To examine the mechanism for this landsliding characteristic, samples (weathered serpentinite) were taken from the field, and their shear behaviours examined using ring shear tests. The test results revealed that the residual shear strength of the samples is positively dependent on the shear rate, which may provide an explanation for the continuous acceleratingdecelerating process of the landsliding. The roughness of the shear surface and the microstructure of the shear zone were measured and observed by laser microscope and SEM techniques in an attempt to clarify the mechanism of shear rate effect on the residual shear strength. Copyright ?? 2010 John Wiley & Sons, Ltd.
15. Impact toughness and microstructure relationship in niobium- and vanadium-microalloyed steels processed with varied cooling rates to similar yield strength
Energy Technology Data Exchange (ETDEWEB)
Shanmugam, S. [Center for Structural and Functional Materials and Department of Chemical Engineering, University of Louisiana at Lafayette, LA 70504-4130 (United States); Misra, R.D.K. [Center for Structural and Functional Materials and Department of Chemical Engineering, University of Louisiana at Lafayette, LA 70504-4130 (United States)]. E-mail: [email protected]; Mannering, T. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Panda, D. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Jansto, S.G. [Reference Metals, 1000 Old Pond Road, Bridgeville, PA 15017 (United States)
2006-11-15
We describe here the relationship between microstructure and impact toughness behavior as a function of cooling rate for industrially processed Nb- and V-microalloyed steels of almost similar yield strength ({approx}60 ksi). Both Nb- and V-microalloyed steels exhibited increase in toughness with increase in cooling rates during processing. However, Nb-microalloyed steels were characterized by relatively higher toughness than the V-microalloyed steels under identical processing conditions. The microstructure of Nb- and V-microalloyed steels processed at conventional cooling rate, primarily consisted of polygonal ferrite-pearlite microconstituents, while Nb-microalloyed steels besides polygonal ferrite and pearlite contained significant fraction of degenerated pearlite. The microstructure of Nb- and V-microalloyed steels processed at relatively higher cooling rate contained degenerated pearlite and lath-type (acicular) ferrite in addition to the primary ferrite-pearlite constituents. The fraction of degenerated pearlite was higher in Nb-microalloyed steels than in the V-microalloyed steels. In both Nb- and V-microalloyed steels the precipitation characteristics were similar with precipitation occurring at grain boundaries, dislocations, and in the ferrite matrix. Fine-scale ({approx}5-10 nm) precipitation was observed in the ferrite matrix of both the steels. The selected area diffraction (SAD) pattern analysis revealed that these fine precipitates were MC type of niobium and vanadium carbides in the respective steels and followed Baker-Nutting orientation relationship with the ferrite matrix. The microstructural studies suggest that the increase in toughness of Nb-microalloyed steels is attributed to higher fraction of degenerated pearlite in the steel.
16. Impact toughness and microstructure relationship in niobium- and vanadium-microalloyed steels processed with varied cooling rates to similar yield strength
International Nuclear Information System (INIS)
Shanmugam, S.; Misra, R.D.K.; Mannering, T.; Panda, D.; Jansto, S.G.
2006-01-01
We describe here the relationship between microstructure and impact toughness behavior as a function of cooling rate for industrially processed Nb- and V-microalloyed steels of almost similar yield strength (∼60 ksi). Both Nb- and V-microalloyed steels exhibited increase in toughness with increase in cooling rates during processing. However, Nb-microalloyed steels were characterized by relatively higher toughness than the V-microalloyed steels under identical processing conditions. The microstructure of Nb- and V-microalloyed steels processed at conventional cooling rate, primarily consisted of polygonal ferrite-pearlite microconstituents, while Nb-microalloyed steels besides polygonal ferrite and pearlite contained significant fraction of degenerated pearlite. The microstructure of Nb- and V-microalloyed steels processed at relatively higher cooling rate contained degenerated pearlite and lath-type (acicular) ferrite in addition to the primary ferrite-pearlite constituents. The fraction of degenerated pearlite was higher in Nb-microalloyed steels than in the V-microalloyed steels. In both Nb- and V-microalloyed steels the precipitation characteristics were similar with precipitation occurring at grain boundaries, dislocations, and in the ferrite matrix. Fine-scale (∼5-10 nm) precipitation was observed in the ferrite matrix of both the steels. The selected area diffraction (SAD) pattern analysis revealed that these fine precipitates were MC type of niobium and vanadium carbides in the respective steels and followed Baker-Nutting orientation relationship with the ferrite matrix. The microstructural studies suggest that the increase in toughness of Nb-microalloyed steels is attributed to higher fraction of degenerated pearlite in the steel
17. Role of microstructure in the mean stress dependence of fatigue strength in Ti-6Al-4V alloy
Energy Technology Data Exchange (ETDEWEB)
Ivanova, S.G.; Cohen, F.S.; Biederman, R.R.; Sisson, R.D. Jr.
1999-07-01
The high cycle fatigue properties of Ti-6Al-4V alloy with six different microstructure/texture combinations were investigated. Only materials with lamellar and fine bimodal microstructures exhibited linear Goodman relationship on the constant fatigue life diagram. Materials with coarse bimodal and equiaxed microstructures had anomalous mean stress dependency, with HCF strength at intermediate mean stresses being significantly lower than predicted by Goodman relationship, regardless of whether material was forged or cross-rolled. The role of microstructure in mean stress sensitivity behavior of Ti-6Al-4V is studied. Cyclic strain tests were conducted for all microstructures, and the results of strain-controlled and stress-controlled cyclic tests are compared and discussed.
18. The dependence of potential well formation on the magnetic field strength and electron injection current in a polywell device
International Nuclear Information System (INIS)
Cornish, S.; Gummersall, D.; Carr, M.; Khachan, J.
2014-01-01
A capacitive probe has been used to measure the plasma potential in a polywell device in order to observe the dependence of potential well formation on magnetic field strength, electron injection current, and polywell voltage bias. The effectiveness of the capacitive probe in a high energy electron plasma was determined by measuring the plasma potential of a planar diode with an axial magnetic field. The capacitive probe was translated along the axis of one of the field coils of the polywell, and the spatial profile of the potential well was measured. The confinement time of electrons in the polywell was estimated with a simple analytical model which used the experimentally observed potential well depths, as well as a simulation of the electron trajectories using particle orbit theory
19. A delay-dependent LMI approach to dynamics analysis of discrete-time recurrent neural networks with time-varying delays
International Nuclear Information System (INIS)
Song, Qiankun; Wang, Zidong
2007-01-01
In this Letter, the analysis problem for the existence and stability of periodic solutions is investigated for a class of general discrete-time recurrent neural networks with time-varying delays. For the neural networks under study, a generalized activation function is considered, and the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. By employing the latest free-weighting matrix method, an appropriate Lyapunov-Krasovskii functional is constructed and several sufficient conditions are established to ensure the existence, uniqueness, and globally exponential stability of the periodic solution for the addressed neural network. The conditions are dependent on both the lower bound and upper bound of the time-varying time delays. Furthermore, the conditions are expressed in terms of the linear matrix inequalities (LMIs), which can be checked numerically using the effective LMI toolbox in MATLAB. Two simulation examples are given to show the effectiveness and less conservatism of the proposed criteria
20. Exponential Antisynchronization Control of Stochastic Memristive Neural Networks with Mixed Time-Varying Delays Based on Novel Delay-Dependent or Delay-Independent Adaptive Controller
Directory of Open Access Journals (Sweden)
Minghui Yu
2017-01-01
Full Text Available The global exponential antisynchronization in mean square of memristive neural networks with stochastic perturbation and mixed time-varying delays is studied in this paper. Then, two kinds of novel delay-dependent and delay-independent adaptive controllers are designed. With the ability of adapting to environment changes, the proposed controllers can modify their behaviors to achieve the best performance. In particular, on the basis of the differential inclusions theory, inequality theory, and stochastic analysis techniques, several sufficient conditions are obtained to guarantee the exponential antisynchronization between the drive system and response system. Furthermore, two numerical simulation examples are provided to the validity of the derived criteria.
1. Event-Based $H_\\infty$ State Estimation for Time-Varying Stochastic Dynamical Networks With State- and Disturbance-Dependent Noises.
Science.gov (United States)
2017-10-01
In this paper, the event-based finite-horizon H ∞ state estimation problem is investigated for a class of discrete time-varying stochastic dynamical networks with state- and disturbance-dependent noises [also called (x,v) -dependent noises]. An event-triggered scheme is proposed to decrease the frequency of the data transmission between the sensors and the estimator, where the signal is transmitted only when certain conditions are satisfied. The purpose of the problem addressed is to design a time-varying state estimator in order to estimate the network states through available output measurements. By employing the completing-the-square technique and the stochastic analysis approach, sufficient conditions are established to ensure that the error dynamics of the state estimation satisfies a prescribed H ∞ performance constraint over a finite horizon. The desired estimator parameters can be designed via solving coupled backward recursive Riccati difference equations. Finally, a numerical example is exploited to demonstrate the effectiveness of the developed state estimation scheme.
2. A new perspective on human health risk assessment: Development of a time dependent methodology and the effect of varying exposure durations
International Nuclear Information System (INIS)
Siirila, Erica R.; Maxwell, Reed M.
2012-01-01
We present a new Time Dependent Risk Assessment (TDRA) that stochastically considers how joint uncertainty and inter-individual variability (JUV) associated with human health risk change as a function of time. In contrast to traditional, time independent assessments of risk, this new formulation relays information on when the risk occurs, how long the duration of risk is, and how risk changes with time. Because the true exposure duration (ED) is often uncertain in a risk assessment, we also investigate how varying the magnitude of fixed size durations (ranging between 5 and 70 years) of this parameter affects the distribution of risk in both the time independent and dependent methodologies. To illustrate this new formulation and to investigate these mechanisms for sensitivity, an example of arsenic contaminated groundwater is used in conjunction with two scenarios of different environmental concentration signals resulting from rate dependencies in geochemical reactions. Cancer risk is computed and compared using environmental concentration ensembles modeled with sorption as 1) a linear equilibrium assumption (LEA) and 2) first order kinetics (Kin). Results show that the information attained in the new time dependent methodology reveals how the uncertainty in other time-dependent processes in the risk assessment may influence the uncertainty in risk. We also show that individual susceptibility also affects how risk changes in time, information that would otherwise be lost in the traditional, time independent methodology. These results are especially pertinent for forecasting risk in time, and for risk managers who are assessing the uncertainty of risk. - Highlights: ► A human health, Time Dependent Risk Assessment (TDRA) methodology is presented. ► TDRA relays information on the magnitude, duration, and fluxes of risk in time. ► Kinetic and equilibrium concentration signals show sensitivity in TDRA results. ► In the TDRA results, individual susceptibility
3. Temperature dependent and applied field strength dependent magnetic study of cobalt nickel ferrite nano particles: Synthesized by an environmentally benign method
Science.gov (United States)
Sontu, Uday Bhasker; G, Narsinga Rao; Chou, F. C.; M, V. Ramana Reddy
2018-04-01
Spinel ferrites have come a long way in their versatile applications. The ever growing applications of these materials demand detailed study of material properties and environmental considerations in their synthesis. In this article, we report the effect of temperature and applied magnetic field strength on the magnetic behavior of the cobalt nickel ferrite nano powder samples. Basic structural properties of spinel ferrite nano particles, that are synthesized by an environmentally benign method of auto combustion, are characterized through XRD, TEM, RAMAN spectroscopy. Diffuse Reflectance Spectroscopy (DRS) is done to understand the nickel substitution effect on the optical properties of cobalt ferrite nano particles. Thermo magnetic studies using SQUID in the temperature range 5 K to 400 K and room temperature (300 K) VSM studies are performed on these samples. Fields of 0Oe (no applied field: ZF), 1 kOe (for ZFC and FC curves), 5 kOe (0.5 T), 50 kOe (5T) (for M-H loop study) are used to study the magnetic behavior of these nano particles. The XRD,TEM analysis suggest 40 nm crystallites that show changes in the cation distribution and phase changes in the spinel structure with nickel substitution. Raman micrographs support phase purity changes and cation redistributions with nickel substitution. Diffuse reflectance study on powder samples suggests two band gap values for nickel rich compounds. The Magnetic study of these sample nano particles show varied magnetic properties from that of hard magnetic, positive multi axial anisotropy and single-magnetic-domain structures at 5 K temperature to soft magnetic core shell like structures at 300 K temperature. Nickel substitution effect is non monotonous. Blocking temperature of all the samples is found to be higher than the values suggested in the literature.
4. Relativistic hadrodynamics with field-strength dependent coupling of the scalar fields in Hartree and Hartree-Fock approximation
International Nuclear Information System (INIS)
Lindner, J.
1992-09-01
In this thesis in the framework of our model of the field-strength dependent coupling the properties of infinitely extended, homogeneous, static, spin- and isospin-saturated nuclear matter are studied. Thereby we use the Hartree-Mean-Field and the Hartree-Fock approximation, whereby the influence of the antiparticle states in the Fermi sea is neglected. In chapter 2 the Lagrangian density basing to our model is fixed. Starting from the Walecka model we modify in the Lagrangian density the Linear coupling of the scalar field to the scalar density as follows g S φanti ψψ→g S f(φ) anti ψψ. In chapter 3 we fix three different functions f(φ). For these three cases and for the Walecka model with f(φ)=φ nuclear-matter calculations are performed. In chapter 4 for the Hartree-Fock calculations, but also very especially regarding the molecular-dynamics calculations, the properties of the Dirac spinors in the plane-wave representation are intensively studied. (orig.)
5. Influence of strength training on variables related to elderly autonomy = Influência do treinamento de força sobre variáveis relacionadas à autonomia de idosos
Directory of Open Access Journals (Sweden)
Alessandra Regina Carnelozzi Prati
2012-07-01
Full Text Available The process of aging results in several changes in the organisms, thus, is necessary to search for ways to mitigate the negative effects of this involution process, for this, knowing that the strength improvement represents a greater availability for everyday activities, this study searched at strength training, evidence of possible improvements in variables related to elderly autonomy. Before and after 12 weeks of training, we performed a pre and post-assessment respectively, in which were measured anthropometric variables as body weight, height, body mass index, waist and hip circumference, waist-hip ratio and fat. We also performed a strength test with hand-held and lower-limb dynamometers, besides functional capacity tests as climbing stairs and self-perception performance in activities of daily living. The sample consisted of 12 elderly females without any type of strength training. The results showed a significant improvement in strength and functional capacity, there was also significant reduction of fat, and increase of lean body mass. Concluding, elderly people can enjoy the benefits provided by strength training, especially in autonomy perspective.O processo de envelhecimento traz consigo diversas alterações no organismo de quem o está sofrendo. Desta forma, se faz necessária a busca por maneiras de protelar os efeitos negativos dessa involução, para tanto, sabendo-se que a melhora da força dos sujeitos representa maior disponibilidade destes para as atividades do cotidiano. Este estudo buscou, no treinamento de força, indícios de possíveis melhoras em variáveis relacionadas à autonomia de idosos. Foram realizadas entre 12 semanas de treino, uma pré e uma pós-avaliação, nas quais foram mensuradas variáveis antropométricas como massa corporal, estatura, índice de massa corporal, circunferência de cintura e quadril, relação cintura-quadril e percentual de gordura; também foram realizados testes de força com dinam
6. A new perspective on human health risk assessment: Development of a time dependent methodology and the effect of varying exposure durations
Energy Technology Data Exchange (ETDEWEB)
Siirila, Erica R., E-mail: [email protected] [Hydrologic Science and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Department of Geology and Geological Engineering, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Maxwell, Reed M., E-mail: [email protected] [Hydrologic Science and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Integrated Groundwater Modeling Center (IGWMC), Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Department of Geology and Geological Engineering, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States)
2012-08-01
We present a new Time Dependent Risk Assessment (TDRA) that stochastically considers how joint uncertainty and inter-individual variability (JUV) associated with human health risk change as a function of time. In contrast to traditional, time independent assessments of risk, this new formulation relays information on when the risk occurs, how long the duration of risk is, and how risk changes with time. Because the true exposure duration (ED) is often uncertain in a risk assessment, we also investigate how varying the magnitude of fixed size durations (ranging between 5 and 70 years) of this parameter affects the distribution of risk in both the time independent and dependent methodologies. To illustrate this new formulation and to investigate these mechanisms for sensitivity, an example of arsenic contaminated groundwater is used in conjunction with two scenarios of different environmental concentration signals resulting from rate dependencies in geochemical reactions. Cancer risk is computed and compared using environmental concentration ensembles modeled with sorption as 1) a linear equilibrium assumption (LEA) and 2) first order kinetics (Kin). Results show that the information attained in the new time dependent methodology reveals how the uncertainty in other time-dependent processes in the risk assessment may influence the uncertainty in risk. We also show that individual susceptibility also affects how risk changes in time, information that would otherwise be lost in the traditional, time independent methodology. These results are especially pertinent for forecasting risk in time, and for risk managers who are assessing the uncertainty of risk. - Highlights: Black-Right-Pointing-Pointer A human health, Time Dependent Risk Assessment (TDRA) methodology is presented. Black-Right-Pointing-Pointer TDRA relays information on the magnitude, duration, and fluxes of risk in time. Black-Right-Pointing-Pointer Kinetic and equilibrium concentration signals show
7. The anti-proliferative effect of cation channel blockers in T lymphocytes depends on the strength of mitogenic stimulation.
Science.gov (United States)
Petho, Zoltan; Balajthy, Andras; Bartok, Adam; Bene, Krisztian; Somodi, Sandor; Szilagyi, Orsolya; Rajnavolgyi, Eva; Panyi, Gyorgy; Varga, Zoltan
2016-03-01
Ion channels are crucially important for the activation and proliferation of T lymphocytes, and thus, for the function of the immune system. Previous studies on the effects of channel blockers on T cell proliferation reported variable effectiveness due to differing experimental systems. Therefore our aim was to investigate how the strength of the mitogenic stimulation influences the efficiency of cation channel blockers in inhibiting activation, cytokine secretion and proliferation of T cells under standardized conditions. Human peripheral blood lymphocytes were activated via monoclonal antibodies targeting the TCR-CD3 complex and the co-stimulator CD28. We applied the blockers of Kv1.3 (Anuroctoxin), KCa3.1 (TRAM-34) and CRAC (2-Apb) channels of T cells either alone or in combination with rapamycin, the inhibitor of the mammalian target of rapamycin (mTOR). Five days after the stimulation ELISA and flow cytometric measurements were performed to determine IL-10 and IFN-γ secretion, cellular viability and proliferation. Our results showed that ion channel blockers and rapamycin inhibit IL-10 and IFN-γ secretion and cell division in a dose-dependent manner. Simultaneous application of the blockers for each channel along with rapamycin was the most effective, indicating synergy among the various activation pathways. Upon increasing the extent of mitogenic stimulation the anti-proliferative effect of the ion channel blockers diminished. This phenomenon may be important in understanding the fine-tuning of T cell activation. Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.
8. Are the benefits of autonomy satisfaction and the costs of autonomy frustration dependent on individuals' autonomy strength?
Science.gov (United States)
Van Assche, Jasper; van der Kaap-Deeder, Jolene; Audenaert, Elien; De Schryver, Maarten; Vansteenkiste, Maarten
2018-01-29
From a self-determination theory perspective, individuals are assumed to benefit and suffer from, respectively, the satisfaction and frustration of the psychological need for autonomy, even if they score low on autonomy strength. Yet, previous studies on need strength are scarce, operationalized need strength differently, and produced inconsistent findings. In two studies among 224 South African adults (M age = 24.13, SD = 4.25; 54.0% male) and 156 Belgian prisoners (M age = 38.60, SD = 11.68; 88.5% male), we investigated the moderating role of autonomy valuation and desire in the relations of autonomy satisfaction and frustration with a variety of well-being and ill-being indicators. Study 1 provided some evidence for the moderating role of mostly explicit autonomy desire (rather than explicit autonomy valuation). In Study 2, neither explicit nor implicit autonomy desire played a consistent moderating role. Overall, these findings are congruent with a moderate (albeit not with a strong) interpretation of the universality claim made within self-determination theory, provide initial evidence for a differentiation between deficit-based and growth-oriented interpersonal differences in need strength, and indicate that the potential moderating role of need strength deserves continued attention before any firm conclusions can be drawn. © 2018 Wiley Periodicals, Inc.
9. Microbial community responses to 17 years of altered precipitation are seasonally dependent and coupled to co-varying effects of water content on vegetation and soil C
Science.gov (United States)
Sorensen, Patrick O.; Germino, Matthew J.; Feris, Kevin P.
2013-01-01
Precipitation amount and seasonal timing determine the duration and distribution of water available for plant and microbial activity in the cold desert sagebrush steppe. In this study, we sought to determine if a sustained shift in the amount and timing of precipitation would affect soil microbial diversity, community composition, and soil carbon (C) storage. Field plots were irrigated (+200 mm) during the dormant or growing-season for 17 years. Microbial community responses were assessed over the course of a year at two depths (15–20 cm, 95–100 cm) by terminal restriction fragment length polymorphism (T-RFLP), along with co-occurring changes in plant cover and edaphic properties. Bacterial richness, Shannon Weaver diversity, and composition in shallow soils (15–20 cm) as well as evenness in deep soils (95–100 cm) differed across irrigation treatments during July. Irrigation timing affected fungal community diversity and community composition during the dormant season and most strongly in deep soils (95–100 cm). Dormant-season irrigation increased the ratio of shrubs to forbs and reduced soil C in shallow soils by 16% relative to ambient conditions. It is unclear whether or not soil C will continue to decline with continued treatment application or if microbial adaptation could mitigate sustained soil C losses. Future changes in precipitation timing will affect soil microbes in a seasonally dependent manner and be coupled to co-varying effects of water content on vegetation and soil C.
10. An optimal power-dispatching system using neural networks for the electrochemical process of zinc depending on varying prices of electricity.
Science.gov (United States)
Yang, Chunhua; Deconinck, G; Gui, Weihua; Li, Yonggang
2002-01-01
Depending on varying prices of electricity, an optimal power-dispatching system (OPDS) is developed to minimize the cost of power consumption in the electrochemical process of zinc (EPZ). Due to the complexity of the EPZ, the main factors influencing the power consumption are determined by qualitative analysis, and a series of conditional experiments is conducted to acquire sufficient data, then two backpropagation neural networks are used to describe these relationships quantitatively. An equivalent Hopfield neural network is constructed to solve the optimization problem where a penalty function is introduced into the network energy function so as to meet the equality constraints, and inequality constraints are removed by alteration of the Sigmoid function. This OPDS was put into service in a smeltery in 1998. The cost of power consumption has decreased significantly, the total electrical energy consumption is reduced, and it is also beneficial to balancing the load of the power grid. The actual results show the effectiveness of the OPDS. This paper introduces a successful industrial application and mainly presents how to utilize neural networks to solve particular problems for the real world.
11. Temperature dependence of bending strength for plasma sprayed zirconia coating; Plasuma yosha zirconia himaku no magetsuyosa no ondo izonsei
Energy Technology Data Exchange (ETDEWEB)
Arai, M.; Sakuma, T. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)] Mizutani, T. [Tokyo Inst. of Tech. (Japan)] Kishimoto, K. [Tokyo Inst. of Tech. (Japan). Faculty of Engineering] Saito, M. [Toshiba Corp. (Japan). Heavy Apparatus Engineering Lab.
1998-02-01
Plasma sprayed zirconia applying to the thermal barrier coating in gas turbine has been developing for protecting the hot parts such as blades and nozzles from high-temperature enviroments. In this paper, four point bending tests under various temperature conditions are conducted on plasma sprayed zirconia and its mechanical properties are examined. Results show that the bending strength at room temperature for plasma sprayed zirconia is much lower than that of sintered zirconia and is decreased with the increase in temperature. However, Weibull modulus at each temperature is relatively large and the dispersion of bending strength is very small in comparison with that of sintered zirconia. It is also clarified by the SEM observations of fracture surface that many defects such as debonding and microcrack are responsible for the lower bending strength. 9 refs., 8 figs., 1 tab.
12. Energy dependence of the ratio of isovector effective interaction strengths |JστJτ| from 0° (p,n) cross sections
Science.gov (United States)
Taddeucci, T. N.; Rapaport, J.; Bainum, D. E.; Goodman, C. D.; Foster, C. C.; Gaarde, C.; Larsen, J.; Goulding, C. A.; Horen, D. J.; Masterson, T.; Sugarbaker, E.
1982-02-01
Information concerning the ratio of the isovector effective interaction strengths |JστJτ| may be obtained from the ratio of (p,n) Gamow-Teller and isobaric analog state 0° differential cross sections. We have examined 0° (p,n) data for the energy range 5-200 MeV and find that for energies larger than 50 MeV and for targets with A=7-42 the product of the interaction-strength and distortion-factor ratios |JστJτ|(NστNτ)12 appears to be mass independent and linear as a function of bombarding energy. NUCLEAR REACTIONS 7Li, 13, 14C, 26Mg, 37Cl, 41Ca(p,n), measured σ(θ=0°), GT, IAS transitions, Ep=60-200 MeV. Deduced energy dependence, interaction strength ratio |JστJτ|.
13. Dependence of optical phase modulation on anchoring strength of dielectric shield wall surfaces in small liquid crystal pixels
Science.gov (United States)
Isomae, Yoshitomo; Shibata, Yosei; Ishinabe, Takahiro; Fujikake, Hideo
2018-03-01
We demonstrated that the uniform phase modulation in a pixel can be realized by optimizing the anchoring strength on the walls and the wall width in the dielectric shield wall structure, which is the needed pixel structure for realizing a 1-µm-pitch optical phase modulator. The anchoring force degrades the uniformity of the phase modulation in ON-state pixels, but it also keeps liquid crystals from rotating against the leakage of an electric field. We clarified that the optimal wall width and anchoring strength are 250 nm and less than 10-4 J/m2, respectively.
14. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models Grau de multicolinearidade e variáveis envolvidas na dependência linear em modelos aditivo-dominantes
Directory of Open Access Journals (Sweden)
Juliana Petrini
2012-12-01
15. Impurity strength and impurity domain modulated frequency-dependent linear and second non-linear response properties of doped quantum dots
Energy Technology Data Exchange (ETDEWEB)
Datta, Nirmal Kumar [Department of Physics, Suri Vidyasagar College, Suri, Birbhum 731 101, West Bengal (India); Ghosh, Manas [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India)
2011-08-15
We explore the pattern of frequency-dependent linear and second non-linear optical responses of repulsive impurity doped quantum dots harmonically confined in two dimensions. The dopant impurity potential chosen assumes a Gaussian form and it is doped into an on-center location. The quantum dot is subject to a periodically oscillating external electric field. For some fixed values of transverse magnetic field strength ({omega}{sub c}) and harmonic confinement potential ({omega}{sub 0}), the influence of impurity strength (V{sub 0}) and impurity domain ({xi}) on the diagonal components of the frequency-dependent linear ({alpha}{sub xx} and {alpha}{sub yy}) and second non-linear ({gamma}{sub xxxx} and {gamma}{sub yyyy}) responses of the dot are computed through a linear variational route. The investigations reveal that the optical responses undergo enhancement with increase in both V{sub 0} and {xi} values. However, in the limitingly small dopant strength regime one observes a drop in the optical responses with increase in V{sub 0}. A time-average rate of energy transfer to the system is often invoked to support the findings. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
16. Dependence of adhesion strength between GaN LEDs and sapphire substrate on power density of UV laser irradiation
Energy Technology Data Exchange (ETDEWEB)
Park, Junsu [Department of Nano-Manufacturing Technology, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103 (Korea, Republic of); Sin, Young-Gwan [Department of Nano-Mechatronics, Korea University of Science and Technology (UST), 217 Gajeong-Ro, Yuseong-Gu, Daejeon 34113 (Korea, Republic of); Kim, Jae-Hyun [Department of Nano-Mechanics, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103 (Korea, Republic of); Kim, Jaegu, E-mail: [email protected] [Department of Nano-Manufacturing Technology, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103 (Korea, Republic of)
2016-10-30
17. Detailing magnetic field strength dependence and segmental artifact distribution of myocardial effective transverse relaxation rate at 1.5, 3.0, and 7.0 T.
Science.gov (United States)
Meloni, Antonella; Hezel, Fabian; Positano, Vincenzo; Keilberg, Petra; Pepe, Alessia; Lombardi, Massimo; Niendorf, Thoralf
2014-06-01
Realizing the challenges and opportunities of effective transverse relaxation rate (R2 *) mapping at high and ultrahigh fields, this work examines magnetic field strength (B0 ) dependence and segmental artifact distribution of myocardial R2 * at 1.5, 3.0, and 7.0 T. Healthy subjects were considered. Three short-axis views of the left ventricle were examined. R2 * was calculated for 16 standard myocardial segments. Global and mid-septum R2 * were determined. For each segment, an artifactual factor was estimated as the deviation of segmental from global R2 * value. The global artifactual factor was significantly enlarged at 7.0 T versus 1.5 T (P = 0.010) but not versus 3.0 T. At 7.0 T, the most severe susceptibility artifacts were detected in the inferior lateral wall. The mid-septum showed minor artifactual factors at 7.0 T, similar to those at 1.5 and 3.0 T. Mean R2 * increased linearly with the field strength, with larger changes for global heart R2 * values. At 7.0 T, segmental heart R2 * analysis is challenging due to macroscopic susceptibility artifacts induced by the heart-lung interface and the posterior vein. Myocardial R2 * depends linearly on the magnetic field strength. The increased R2 * sensitivity at 7.0 T might offer means for susceptibility-weighted and oxygenation level-dependent MR imaging of the myocardium. Copyright © 2013 Wiley Periodicals, Inc.
18. Building Strength or Lending an Ear in Legal Conflicts: Dependence and Conflict Asymmetry as Distinct Predictors of Needs for Support
NARCIS (Netherlands)
van Dijk, Maria Anna Jozefa; Giebels, Ellen; Zebel, Sven
2016-01-01
Being aware of psychological aspects of legal conflicts can benefit the efficiency of legal aid. We propose that needs for support may be particularly dependent upon the experience of asymmetry between conflict parties. We distinguish between two types of asymmetry and examine how they relate to
19. Temperature and orientation dependence of the short-term strength characteristics, Young's modulus, and linear expansion coefficient of ZhS6F alloy single crystals
Energy Technology Data Exchange (ETDEWEB)
Svetlov, I L; Sukhanov, N N; Krivko, A I; Roshchina, I N; Khatsinskaia, I M
1987-01-01
Experimental data are presented on the temperature dependence of the short- term strength characteristics, Young's modulus, and linear expansion coefficients of single crystals of a nickel alloy, ZhS6F, with crystallographic orientations along the 001, 111, 011, and 112 lines. It is found that the mechanical properties and Young's modulus of the alloy crystals exibit anisotropy in the temperature range 20-900 C. The linear thermal expansion coefficient is isotropic up to 900 C and equal to that of the equiaxed alloy. 10 references.
20. Grain size-dependent strength of phyllosilicate-rich gouges in the shallow crust: Insights from the SAFOD site
Science.gov (United States)
Phillips, Noah John; White, Joseph Clancy
2017-07-01
The San Andreas Fault Observatory at Depth (SAFOD) drilling project directly sampled a transitional (between creeping and locked) segment of the San Andreas Fault at 2.7 km depth. At the site, changes in strain rate occur between periods of coseismic slip (>10-7 s-1) and interseismic creep (10-10 s-1) over decadal scales ( 30 years). Microstructural observations of core retrieved from the SAFOD site show throughgoing fractures and gouge-rich cores within the fractures, evidence of predominantly brittle deformation mechanisms. Within the gouge-rich cores, strong phases show evidence of deformation by pressure solution once the grain size is reduced to a critical effective grain size. Models of pressure solution-accommodated creep for quartz-phyllosilicate mixtures indicate that viscous weakening of quartz occurs during the interseismic period once a critical effective grain size of 1 μm is achieved, consistent with microstructural observations. This causes pronounced weakening, as the strength of the mixture is then controlled by the frictional properties of the phyllosilicate phases. These results have pronounced implications for the internal deformation of fault zones in the shallow crust, where at low strain rates, deformation is accommodated by both viscous and brittle deformation mechanisms. As strain rates increase, the critical effective grain size for weakening decreases, localizing deformation into the finest-grained gouges until deformation can no longer be accommodated by viscous processes and purely brittle failure occurs.
1. The association between hemispheric specialization for language production and for spatial attention depends on left-hand preference strength.
Science.gov (United States)
Zago, Laure; Petit, Laurent; Mellet, Emmanuel; Jobard, Gaël; Crivello, Fabrice; Joliot, Marc; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie
2016-12-01
Cerebral lateralization for language production and spatial attention and their relationships with manual preference strength (MPS) were assessed in a sample of 293 healthy volunteers, including 151 left-handers, using fMRI during covert sentence production (PROD) and line bisection judgment (LBJ) tasks, as compared to high- and low-level reference tasks. At the group level, we found the expected complementary hemispheric specialization (HS) with leftward asymmetries for PROD within frontal and temporal regions and rightward asymmetries for LBJ within frontal and posterior occipito-parieto-temporal regions. Individual hemispheric (HLI) and regional (frontal and occipital) lateralization indices (LI) were then calculated on the activation maps for PROD and LBJ. We found a correlation between the degree of rightward cerebral asymmetry and the leftward behavioral attentional bias recorded during LBJ task. This correlation was found when LBJ-LI was computed over the hemispheres, in the frontal lobes, but not in the occipital lobes. We then investigated whether language production and spatial attention cerebral lateralization relate to each other, and whether manual preference was a variable that impacted the complementary HS of these functions. No correlation was found between spatial and language LIs in the majority of our sample of participants, including right-handers with a strong right-hand preference (sRH, n=97) and mixed-handers (MH, n=97), indicating that these functions lateralized independently. By contrast, in the group of left-handers with a strong left-hand preference (sLH, n= 99), a negative correlation was found between language and spatial lateralization. This negative correlation was found when LBJ-LI and PROD-LI were computed over the hemispheres, in the frontal lobes and between the occipital lobes for LBJ and the frontal lobes for PROD. These findings underline the importance to include sLH in the study sample to reveal the underlying mechanisms of
2. The time-dependent coupled oscillator model for the motion of a charged particle in the presence of a time-varying magnetic field
International Nuclear Information System (INIS)
Menouar, Salah; Maamache, Mustapha; Choi, Jeong Ryeol
2010-01-01
The dynamics of the time-dependent coupled oscillator model for the motion of a charged particle subjected to a time-dependent external magnetic field is investigated. We use the canonical transformation approach for the classical treatment of the system, whereas the unitary transformation approach is used in managing the system in the framework of quantum mechanics. For both approaches, the original system is transformed into a much more simple system that is the sum of two independent harmonic oscillators with time-dependent frequencies. We therefore easily identify the wavefunctions in the transformed system with the help of an invariant operator of the system. The full wavefunctions in the original system are derived from the inverse unitary transformation of the wavefunctions associated with the transformed system.
3. Q2 Dependence of Quadrupole Strength in the gamma*p-->Delta+(1232) --> p pi0 Transition
International Nuclear Information System (INIS)
Volker Burkert; Kyungseon Joo; Lee Smith; Ralph Minehart
2002-01-01
Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q 2 dependence of the magnetic (M 1+ ), electric (E 1+ ), and scalar (S 1+ ) multipoles in the γ*p → Δ + (1232) → pπ 0 transition. New precision measurements of the ratios E 1+ /M 1+ and S 1+ /M 1+ are reported here over the range Q 2 = 0.4-1.8 GeV 2 . Results are best described by recent unitary models in which the pion cloud plays a dominant role
4. Right- and left-brain hemisphere. Rhythm in reaction time to light signals is task-load-dependent: age, gender, and handgrip strength rhythm comparisons.
Science.gov (United States)
Reinberg, Alain; Bicakova-Rocher, Alena; Mechkouri, Mohamed; Ashkenazi, Israel
2002-11-01
In healthy mature subjects simple reaction time (SRT) to a single light signal (an easy task) is associated with a prominent rhythm with tau = 24 h of dominant (DH) as well as nondominant (NDH) hand performance, while three-choice reaction time (CRT), a complex task, is associated with tau = 24 h of the DH but tau gender on the difference in tau of the NDH and DH, as it relates to the corresponding cortical hemisphere of the brain, in comparison to the rhythm in handgrip strength. Healthy subjects, 9 (5 M and 4 F) adolescents 10-16 yr of age and 15 (8 M and 7 F) adults 18-67 yr of age, active between 08:00 +/- 1 h and 23:00 +/- 1:30 h and free of alcohol, tobacco, and drug consumption volunteered. Data were gathered longitudinally at home and work 4-7 times daily for 11-20 d. At each test time the following variables were assessed: grip strength of both hands (Dynamometer: Colin-Gentile, Paris, France); single reaction time to a yellow signal (SRT); and CRT to randomized yellow, red, or green signal series with varying instruction from test to test (Psycholog-24: Biophyderm, France). Rhythms in the performance in SRT, CRT, and handgrip strength of both DH and NDH were explored. The sleep-wake rhythm was assessed by sleep-logs, and in a subset of 14 subjects it was also assessed by wrist actigraphy (Mini-Motionlogger: AMI, Ardsley NY). Exploration of the prominent period tau of time series was achieved by a special power spectra analysis for unequally spaced data. Cosinor analysis was used to quantify the rhythm amplitude A and rhythm-adjusted mean M of the power spectral analysis determined trial tau. A 24h sleep-wake rhythm was detected in almost all cases. In adults, a prominent tau of 24 h characterized the performance of the easy task by both the DH and NDH. In adults a prominent tau of 24 h was also detected in the complex CRT task performed by the DH, but for the NDH the tau was gender-related but was age-related since it was seldom observed in adolescent
5. Accelerated Strength Testing of Thermoplastic Composites
Science.gov (United States)
Reeder, J. R.; Allen, D. H.; Bradley, W. L.
1998-01-01
Constant ramp strength tests on unidirectional thermoplastic composite specimens oriented in the 90 deg. direction were conducted at constant temperatures ranging from 149 C to 232 C. Ramp rates spanning 5 orders of magnitude were tested so that failures occurred in the range from 0.5 sec. to 24 hrs. (0.5 to 100,000 MPa/sec). Below 204 C, time-temperature superposition held allowing strength at longer times to be estimated from strength tests at shorter times but higher temperatures. The data indicated that a 50% drop in strength might be expected for this material when the test time is increased by 9 orders of magnitude. The shift factors derived from compliance data applied well to the strength results. To explain the link between compliance and strength, a viscoelastic fracture model was investigated. The model, which used compliance as input, was found to fit the strength data only if the critical fracture energy was allowed to vary with temperature reduced stress rate. This variation in the critical parameter severely limits its use in developing a robust time-dependent strength model. The significance of this research is therefore seen as providing both the indication that a more versatile acceleration method for strength can be developed and the evidence that such a method is needed.
6. Tooth movement and changes in periodontal tissue in response to orthodontic force in rats vary depending on the time of day the force is applied.
Science.gov (United States)
Miyoshi, K; Igarashi, K; Saeki, S; Shinoda, H; Mitani, H
2001-08-01
The purpose of this study was to investigate whether there are any differences in tooth movement or in the response of periodontal tissue to orthodontic force when the force is applied at different times of the day. One hundred 6-week-old male Wistar rats were divided into one control group without force application and three experimental groups based on the time of day the force was applied to the upper first molars. Animals in the whole-day group received force continuously throughout the experimental period, while animals in the light- and dark-period groups received force only during the light (07:00-19:00) or dark period (19:00-07:00), respectively. Tooth movement was measured using the occlusal view of a precise plaster model with a profile projector. Periodontal tissues were evaluated histologically. The time course of tooth movement varied among the groups. Tooth movement over 21 days in the whole-day and light-period groups was about twice that as in the dark-period group. The formation of new bone on the tension side in the whole-day and light-period groups was more than twice that as in the dark-period group. On the pressure side, more osteoclasts appeared on the alveolar bone in the whole-day and light-period groups than in the dark-period group. The light-period group showed less extensive hyalinization of the periodontal ligament (PDL) than the whole-day group. The area of root resorption on day 21 also varied among the groups. Interference by masticatory forces did not seem to be a principal cause of the decreased tooth movement in the dark-period group. These results indicate that there are considerable variations in tooth movement and in the response of periodontal tissue to orthodontic force when the force is applied at different times of the day in rats. The results suggest that diurnal rhythms in bone metabolism have important implications in orthodontic treatment.
7. Size-dependent oscillator strength and quantum efficiency of CdSe quantum dots controlled via the local density of states
DEFF Research Database (Denmark)
Leistikow, M.D.; Johansen, Jeppe; Kettelarij, A.J.
2009-01-01
We study experimentally time-resolved emission of colloidal CdSe quantum dots in an environment with a controlled local density of states LDOS. The decay rate is measured versus frequency and as a function of distance to a mirror. We observe a linear relation between the decay rate and the LDOS, ...... with the measured radiative rates. Our results are relevant for applications of CdSe quantum dots in spontaneous emission control and cavity quantum electrodynamics.......We study experimentally time-resolved emission of colloidal CdSe quantum dots in an environment with a controlled local density of states LDOS. The decay rate is measured versus frequency and as a function of distance to a mirror. We observe a linear relation between the decay rate and the LDOS......, allowing us to determine the size-dependent quantum efficiency and oscillator strength. We find that the quantum efficiency decreases with increasing emission energy mostly due to an increase in nonradiative decay. We manage to obtain the oscillator strength of the important class of CdSe quantum dots...
8. The strength of a calcified tissue depends in part on the molecular structure and organization of its constituent mineral crystals in their organic matrix
Science.gov (United States)
Landis, W. J.
1995-01-01
High-voltage electron-microscopic tomographic (3D) studies of the ultrastructural interaction between mineral and organic matrix in a variety of calcified tissues reveal different crystal structural and organizational features in association with their respective organic matrices. In brittle or weak pathologic or ectopic calcifications, including examples of osteogenesis imperfecta, calciphylaxis, calcergy, and dermatomyositis, hydroxyapatite crystals occur in various sizes and shapes and are oriented and aligned with respect to collagen in a manner which is distinct from that found in normal calcified tissues. A model of collagen-mineral interaction is proposed which may account for the observed crystal structures and organization. The results indicate that the ultimate strength, support, and other mechanical properties provided by a calcified tissue are dependent in part upon the molecular structure and arrangement of its constituent mineral crystals within their organic matrix.
9. [Independence in Plastic Surgery - Benefit or Barrier? Analysis of the Publication Performance in Academic Plastic Surgery Depending on Varying Organisational Structures].
Science.gov (United States)
Schubert, C D; Leitsch, S; Haertnagl, F; Haas, E M; Giunta, R E
2015-08-01
Despite its recognition as an independent specialty, at German university hospitals the field of plastic surgery is still underrepresented in terms of independent departments with a dedicated research focus. The aim of this study was to analyse the publication performance within the German academic plastic surgery environment and to compare independent departments and dependent, subordinate organisational structures regarding their publication performance. Organisational structures and number of attending doctors in German university hospitals were examined via a website analysis. A pubmed analysis was applied to assess the publication performance (number of publications, cumulative impact factor, impact factor/publication, number of publications/MD, number of publications/unit) between 2009 and 2013. In a journal analysis the distribution of the cumulative impact factor and number of publications in different journals as well as the development of the impact factor in the top journals were analysed. Out of all 35 university hospitals there exist 12 independent departments for plastic surgery and 8 subordinate organisational structures. In 15 university hospitals there were no designated plastic surgery units. The number of attending doctors differed considerably between independent departments (3.6 attending doctors/unit) and subordinate organisational structures (1.1 attending doctors/unit). The majority of publications (89.0%) and of the cumulative impact factor (91.2%) as well as most of the publications/MD (54 publications/year) and publications/unit (61 publications/year) were created within the independent departments. Only in departments top publications with an impact factor > 5 were published. In general a negative trend regarding the number of publications (- 13.4%) and cumulative impact factor (- 28.9%) was observed. 58.4% of all publications were distributed over the top 10 journals. Within the latter the majority of articles were published in
10. The strength of polyaxial locking interfaces of distal radius plates.
Science.gov (United States)
Hoffmeier, Konrad L; Hofmann, Gunther O; Mückley, Thomas
2009-10-01
11. 股指期货对现货时变相依结构的多尺度研究%Multi-scale Study on Time-varying Dependency Structure between the Stock Index Futures and the Actual
Institute of Scientific and Technical Information of China (English)
彭选华; 傅强
2011-01-01
Copula theory is very popular to model the dependency structure between the price of future and spot market in financial analysis including risk hedge,hedging portfolio and price discovery.This paper considers the innovation asymmetric impact on the price and the time-varying characteristics of the dependency structure,and constructs a time-varying T-Copula-GJR-GARCH model by using a GJR-GARCH model to fit the two returns,respectively.By choosing the DCC equation to depict the dynamic structure of the time-varying coefficient,and based on high frequency price data from 5 to 60 minute of the Hu-Shen 300 index futures and stock market,we establish a time-varying T-Copula-GJR-GARCH（1,1）-T model by time-scale.The results indicate the dependent structure changes over time-scale,which may be explained by the market microstructure and heterogeneity of the investors.Hence,this paper reveals the potential time-varying dependency patterns between China＇s stock index futures and spot market at multi-scale time horizons.%股指期货与现货之间的相依结构是Copula理论在金融分析中套期保值、组合风险对冲及价格发现等应用的热点。考虑到新息对价格的非对称冲击和相依结构的时变特征,利用GJR-GARCH模型对股指期货和现货的收益率序列建模,选用DCC方程刻画二者之间时变相关系数的演化结构,构建时变T-Copula-GJR-GARCH模型。针对沪深300指数现货与期货5～60分钟的高频数据,分尺度拟合时变T-Copula-GJR-GARCH（1,1）-t模型,结果表明相依结构随时间尺度变化而变化,这或许可由市场微观结构差异及投资者的
12. Anisotropic Concrete Compressive Strength
DEFF Research Database (Denmark)
Gustenhoff Hansen, Søren; Jørgensen, Henrik Brøner; Hoang, Linh Cao
2017-01-01
When the load carrying capacity of existing concrete structures is (re-)assessed it is often based on compressive strength of cores drilled out from the structure. Existing studies show that the core compressive strength is anisotropic; i.e. it depends on whether the cores are drilled parallel...
13. The astrophysical r-process and its dependence on properties of nuclei far from stability: Beta strength functions and neutron capture rates
International Nuclear Information System (INIS)
Klapdor, H.V.; Metzinger, J.; Oda, T.; Thielemann, F.K.; Hillebrandt, W.
1981-01-01
The question of the astrophysical site of the rapid neutron capture (r-) process which is believed to be responsible for the production of the heavy elements in the universe has been a problem in astrophysics for more than two decades. The solution of this problem is not only dependent on the development of realistic astrophysical supernova models, i.e. correct treatment of the hydrodynamics of gravitational collapse and supernova explosion and the equation of state of hot and dense matter, but is shown in this paper to be very sensitive also to 'standard' nuclear physics properties of nuclei far from stability such as beta decay properties and neutron capture rates. For both of the latter, strongly oversimplifying assumptions, not applying the development in nuclear physics during the last decade, have been made in almost all r-process calculations performed up to now. A critical discussion of the state of the art of such calculations seems therefore to be indicated. In this paper procedures are described which allow one to obtain: 1) β-decay properties (decay rates, β-delayed neutron emissions and fission rates); 2) neutron capture rates for neutron-rich nuclei considerably improved over what has been used up to now. The beta strength functions are calculated for approx. equal to6000 nuclei between beta stability line and neutron drip line. By hydrodynamical supernova explosion calculations using realistic stellar models it is shown that as a consequence of the improved β-rates explosive He burning is a convincing alternative site to the 'classical' r-process whose existence still is questionable. The new β-rates will be important also for the investigation of further astrophysical sites producing heavy elements such as the r(n)-processes in explosive C or Ne burning. (orig.)
14. Can a soda-lime glass be used to demonstrate how patterns of strength dependence are influenced by pre-cementation and resin-cementation variables?
LENUS (Irish Health Repository)
Hooi, Paul
2013-01-01
To determine how the variability in biaxial flexure strength of a soda-lime glass analogue for a PLV and DBC material was influenced by precementation operative variables and following resin-cement coating.
15. Time-varying Crash Risk
DEFF Research Database (Denmark)
Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae
We estimate a continuous-time model with stochastic volatility and dynamic crash probability for the S&P 500 index and find that market illiquidity dominates other factors in explaining the stock market crash risk. While the crash probability is time-varying, its dynamic depends only weakly on re...
16. Location of the major 2Psub(1/2) strength in 49Sc by forward angle heavy-ion j dependence
International Nuclear Information System (INIS)
Kemper, K.W.; Zeller, A.F.; Ophel, T.R.
1977-12-01
Foward angle 48 Ca( 7 Li, 6 He) data show the 4.49 MeV state in 49 Sc to be 2Psub(1/2) and not 2Psub(3/2) as reported in an earlier 48 Ca( 15 N, 14 C) work. The ( 3 He,d) spectroscopic factor of 0.55 indicates that this state has the major components of the 2psub(1/2) strength in 49 Sc. (Author)
17. Effects of starvation on the transport of Escherichia coli K12 in saturated porous media are dependent on pH and ionic strength
Science.gov (United States)
Xu, S.; Walczak, J. J.; Wang, L.; Bardy, S. L.; Li, J.
2010-12-01
In this research, we investigate the effects of starvation on the transport of E. coli K12 in saturated porous media. Particularly, we examine the relationship between such effects and the pH and ionic strength of the electrolyte solutions that were used to suspend bacterial cells. E. coli K12 (ATCC 10798) cells were cultured using either Luria-Bertani Miller (LB-Miller) broth (10 g trypton, 5 g yeast extract and 10 g NaCl in 1 L of deionized water) or LB-Luria broth (10 g tryptone, 5 g yeast extract and 0.5 g NaCl in 1 L of deionized water). Both broths had similar pH (~7.1) but differed in ionic strength (LB-Miller: ~170 mM, LB-Luria: ~ 8 mM). The bacterial cells were then harvested and suspended using one of the following electrolyte solutions: phosphate buffered saline (PBS) (pH ~7.2; ionic strength ~170 mM), 168 mM NaCl (pH ~5.7), 5% of PBS (pH ~ 7.2; ionic strength ~ 8 mM) and 8 mM NaCl (pH ~ 5.7). Column transport experiments were performed at 0, 21 and 48 hours following cell harvesting to evaluate the change in cell mobility over time under “starvation” conditions. Our results showed that 1) starvation increased the mobility of E. coli K12 cells; 2) the most significant change in mobility occurred when bacterial cells were suspended in an electrolyte solution that had different pH and ionic strength (i.e., LB-Miller culture suspended in 8 mM NaCl and LB-Luria culture suspended in 168 mM Nacl); and 3) the change in cell mobility primarily occurred within the first 21 hours. The size of the bacterial cells was measured and the surface properties (e.g., zeta potential, hydrophobicity, cell-bound protein, LPS sugar content, outer membrane protein profiles) of the bacterial cells were characterized. We found that the measured cell surface properties could not fully explain the observed changes in cell mobility caused by starvation.
18. Organism traits determine the strength of scale-dependent bio-geomorphic feedbacks: a flume study on three intertidal plant species
NARCIS (Netherlands)
Bouma, T.J.; Temmerman, S.; van Duren, L.A.; Martini, E.; Vandenbruwaene, W.; Callaghan, D.P.; Balke, T.; Biermans, G.; Klaassen, P.C.; van Steeg, R.; Dekker, F.; van de Koppel, J.; de Vries, Mindert; Herman, P.M.J.
2013-01-01
There is a growing recognition of the important role of scale-dependent feedback for biogeomorphological landscape formation, where organisms locally improve survival and growth but at the same time negatively affect organisms at larger distance. However, little is known on how scale-dependent
19. Organism traits determine the strength of scale-dependent bio-geomorphic feedbacks: A flume study on three intertidal plant species
NARCIS (Netherlands)
Bouma, T.J.; Temmerman, S.; van Duren, L.A.; Martini, E.; Vandenbruwaene, W.; Callaghan, D.P.; Balke, T.; Biermans, G.; Klaassen, P.C.; van Steeg, R.; Dekker, F.; van de Koppel, J.; Herman, P.M.J.; de Vries, M.B.
2013-01-01
There is a growing recognition of the important role of scale-dependent feedback for biogeomorphological landscape formation, where organisms locally improve survival and growth but at the same time negatively affect organisms at larger distance. However, little is known on how scale-dependent
20. The Effect on Final Bond Strength of Bracket Manipulation Subsequent To Initial Positioning
Science.gov (United States)
Beebe, David A.
The shear bond strength of light activated orthodontic adhesives varies according to the composition of the material, placement protocol, and time prior to light curing. Manipulating brackets after their initial placement on a tooth can disrupt the adhesive's polymerization and compromise final bond strength. No previous research has investigated how a specific degree of manipulation, and the amount of time elapsed prior to curing, under specific lighting conditions, affects the orthodontic adhesives shear bond strength. Victory SeriesRTM, MBT prescription, premolar (3M Unitek, Monrovia, CA) orthodontic brackets were bonded using three different adhesives to sixty (60) bicuspids and varying the time after bracket manipulation before curing. The shear bond strength was calculated for each specimen. The brackets were debonded and the same teeth were rebonded with new, identical brackets, using the same protocol and under the same conditions. The results showed a statistically significant difference between the shear bond strength of Transbond XT and Grengloo, with Transbond XT having the highest strength. There was also a statistically significance difference in bond strength between the group cured 30 seconds after manipulation and the groups manipulated at different intervals prior to curing, with the 30 second group having the highest bond strength. This study confirms that various orthodontic adhesives have different bond strengths depending on manipulation and varying times prior to curing each adhesive.
1. Genome-wide linkage scan for maximum and length-dependent knee muscle strength in young men: significant evidence for linkage at chromosome 14q24.3.
Science.gov (United States)
De Mars, G; Windelinckx, A; Huygens, W; Peeters, M W; Beunen, G P; Aerssens, J; Vlietinck, R; Thomis, M A I
2008-05-01
Maintenance of high muscular fitness is positively related to bone health, functionality in daily life and increasing insulin sensitivity, and negatively related to falls and fractures, morbidity and mortality. Heritability of muscle strength phenotypes ranges between 31% and 95%, but little is known about the identity of the genes underlying this complex trait. As a first attempt, this genome-wide linkage study aimed to identify chromosomal regions linked to muscle and bone cross-sectional area, isometric knee flexion and extension torque, and torque-length relationship for knee flexors and extensors. In total, 283 informative male siblings (17-36 years old), belonging to 105 families, were used to conduct a genome-wide SNP-based multipoint linkage analysis. The strongest evidence for linkage was found for the torque-length relationship of the knee flexors at 14q24.3 (LOD = 4.09; p<10(-5)). Suggestive evidence for linkage was found at 14q32.2 (LOD = 3.00; P = 0.005) for muscle and bone cross-sectional area, at 2p24.2 (LOD = 2.57; p = 0.01) for isometric knee torque at 30 degrees flexion, at 1q21.3, 2p23.3 and 18q11.2 (LOD = 2.33, 2.69 and 2.21; p<10(-4) for all) for the torque-length relationship of the knee extensors and at 18p11.31 (LOD = 2.39; p = 0.0004) for muscle-mass adjusted isometric knee extension torque. We conclude that many small contributing genes rather than a few important genes are involved in causing variation in different underlying phenotypes of muscle strength. Furthermore, some overlap in promising genomic regions were identified among different strength phenotypes.
2. A Critical Analysis of Grain-Size and Yield-Strength Dependence of Near-Threshold Fatigue-Crack Growth in Steels.
Science.gov (United States)
1981-07-15
of high-strength steel ), and a host of microstructural types (ferritic, martensitic, pearlitic, bainitic , austenitic). Accession For NTIS GRA&l DTIC...IN STEELS , : RPRNGO.RPRTNMR 1~A Tw.R CONTRACT OA4A&XMUt8~ G/~ ! R./koderl L.A./Cooleyad T.W./Crooker 2 .{I 9PERFORMING ORGANIZATION NAME AND A10R4SI...growth Steels Microstructure Ferrous alloys Structure-sensitive crack growth 20 ABSTRACT (Con~tinue an r*,er.. side it necesar and Identity by black
3. Statistical considerations of graphite strength for assessing design allowable stresses
International Nuclear Information System (INIS)
Ishihara, M.; Mogi, H.; Ioka, I.; Arai, T.; Oku, T.
1987-01-01
Several aspects of statistics need to be considered to determine design allowable stresses for graphite structures. These include: 1) Statistical variation of graphite material strength. 2) Uncertainty of calculated stress. 3) Reliability (survival probability) required from operational and safety performance of graphite structures. This paper deals with some statistical considerations of structural graphite for assessing design allowable stress. Firstly, probability distribution functions of tensile and compressive strengths are investigated on experimental Very High Temperature candidated graphites. Normal, logarithmic normal and Weibull distribution functions are compared in terms of coefficient of correlation to measured strength data. This leads to the adaptation of normal distribution function. Then, the relation between factor of safety and fracture probability is discussed on the following items: 1) As the graphite strength is more variable than metalic material's strength, the effect of strength variation to the fracture probability is evaluated. 2) Fracture probability depending on survival probability of 99 ∼ 99.9 (%) with confidence level of 90 ∼ 95 (%) is discussed. 3) As the material properties used in the design analysis are usually the mean values of their variation, the additional effect of these variations on the fracture probability is discussed. Finally, the way to assure the minimum ultimate strength with required survival probability with confidence level is discussed in view of statistical treatment of the strength data from varying sample numbers in a material acceptance test. (author)
4. Frictional strength of wet and dry montmorillonite
Science.gov (United States)
Morrow, C. A.; Moore, D. E.; Lockner, D. A.
2017-05-01
Montmorillonite is a common mineral in fault zones, and its low strength relative to other common gouge minerals is important in many models of fault rheology. However, the coefficient of friction, μ, varies with degree of saturation and is not well constrained in the literature due to the difficulty of establishing fully drained or fully dried states in the laboratory. We measured μ of both saturated and oven-dried montmorillonite at normal stresses up to 700 MPa. Care was taken to shear saturated samples slowly enough to avoid pore fluid overpressure. For saturated samples, μ increased from 0.10 to 0.28 with applied effective normal stress, while for dry samples μ decreased from 0.78 to 0.45. The steady state rate dependence of friction, (a - b), was positive, promoting stable sliding. The wide disparity in reported frictional strengths can be attributed to experimental procedures that promote differing degrees of partial saturation or overpressured pore fluid conditions.
5. The astrophysical r-process and its dependence on properties of nuclei far from stability beta strength functions and neutron capture rates
CERN Document Server
Klapdor-Kleingrothaus, H V; Metzinger, J; Oda, T; Thielemann, F K
1981-01-01
It is shown that the astrophysical r-process and the question of its site are very sensitive to 'standard' nuclear physics parameters like the beta decay properties and neutron capture rates. Since for these quantities in almost all r-process calculations up to now, and also in all estimates of the production rates of chronometric pairs, only very rough assumptions have been made, it is attempted to present procedures which put the calculation of these quantities for nuclei far from stability on a reliable physical basis. This is done by a microscopic description of the beta strength function and by using a statistical model based on a 'next to first principles' optical potential including effects of deformation for the neutron capture rates. The beta -decay rates for approximately 6000 nuclei between the beta -stability line and the neutron drip line are calculated. The heavy element synthesis by explosive He burning then is calculated using these beta -rates and using realistic star models treating the supe...
6. On the nature of anomalies in temperature dependence of the OKh18N1OT steel yield strength after thermal cycling in the low temperature range
International Nuclear Information System (INIS)
Medvedev, E.M.; Lavrent'ev, F.F.; Kurmanova, T.N.
1978-01-01
Investigated were structural transformations in 0Kh18N10T steel as a result of heating and cooling and of deformation within the range of temperatures between 300 and 77 K, the quantity relationships between the said transformations and the variation of the yield limit with the temperature. The studies were conducted by metallography and mechanical test methods. It was shown that an increase in the number of heating and cooling cycles correlates with a loss in strength of the steel while deformation at 77 K. This anomaly in the temperature relationship of the yield limit is related to the appearance in the course of deformation of α-martensite with a BCC lattice. Deformation at 300 K increases the amount ea of epsilon-martensite, a decrses the effectve size of grain and, in consequence, increases the yield limit. The relationship between the yield limit and the grain size at the temperature of 300 K is described adequately by the Hall-Petch equation
7. Temperature-dependent tensile strength, surface roughness diagnostics, and magnetic support and positioning of polymer ICF shells. Final report, October 1, 1993--April 30, 1995
International Nuclear Information System (INIS)
Honig, A.
1995-01-01
During the course of this grant, we perfected emissivity and accommodation coefficient measurements on polymer ICF shells in the temperature range 250 to 350 K. Values for polystyrene shells are generally between 10 -2 and 10 -3 , which are very advantageous for ICF at cryogenic temperatures. Preliminary results on Br doped target shells indicate an accommodation coefficient, presumably associated with surface roughness on an atomic scale, about an order of magnitude larger than for ordinary polystyrene target shells. We also constructed apparatus with optical access for low temperature tensile strength and emissivity measurements, and made preliminary tests on this system. Magnetic shells were obtained both from GDP coating and from doping styrene with 10 manometer size ferromagnetic particles. The magnetic properties were measured through electron spin resonance (ESR). These experiments confirm the applicability of the Curie law, and establish the validity of using ESR measurements to determine shell temperature in the low temperature regime from 4K to 250K, thus complementing our presently accessible range. The high electron spin densities (> 10 20 /CM 3 ) suggest magnetic levitation should be feasible at cryogenic temperatures. This work has resulted in two conference presentations, a Technical Report, a paper to be published in Fusion Technology, and a Master's Thesis
8. Dose-dependent ATP depletion and cancer cell death following calcium electroporation, relative effect of calcium concentration and electric field strength
DEFF Research Database (Denmark)
Hansen, Emilie Louise; Sozer, Esin Bengisu; Romeo, Stefania
2015-01-01
death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. METHODS: In three human cell lines--H69 (small-cell lung cancer), SW780 (bladder cancer), and U937 (leukaemia), viability...... was observed with fluorescence confocal microscopy of quinacrine-labelled U937 cells. RESULTS: Both H69 and SW780 cells showed dose-dependent (calcium concentration and electric field) decrease in intracellular ATP (p...-dependently reduced cell survival and intracellular ATP. Increasing extracellular calcium allows the use of a lower electric field. GENERAL SIGNIFICANCE: This study supports the use of calcium electroporation for treatment of cancer and possibly lowering the applied electric field in future trials....
9. Compressive strain-dependent bending strength property of Al2O3-ZrO2 (1.5 mol% Y2O3) composites performance by HIP
International Nuclear Information System (INIS)
Reyes-Rojas, A.; Esparza-Ponce, H.; De la Torre, S.D.; Torres-Moye, E.
2009-01-01
Nanometric powders and sintered ceramics of Al 2 O 3 -ZrO 2 (1.5 mol% Y 2 O 3 ) prepared by hot isostatic pressing HIP have been studied. A detailed crystallographic study has been performed through X-ray diffraction, Williamson-Hall method, Rietveld method and high-resolution electron microscopy HREM analysis. The crystallographic structure data, such as domain size, lattice parameters, wt% phase, and micro-strain direction have been obtained using Rietveld refinement and Williamson-Hall methods. The results revealed that the compressive strain (ε) increased from 0.56 to 1.18 (10 -3 ) as the t-ZrO 2 content increased too. The HREM interface study conducted along the [0 0 0 1]Al 2 O 3 ||[0 0 1]ZrO 2 zone axis revealed a micro-strain lattice distortion accumulated at the grain boundary due to the ZrO 2 martensitic phase transformation on cooling, t-ZrO 2 grains coalescence and to the grain growth of α-Al 2 O 3 which cause elongated tetragonal crystals. Micro-strain lattice distortion is adjusted by the shear displacements of the planes (1 1 0) and (11-bar0) along [1-bar10] and [1-bar1-bar0] crystallographic directions, respectively; these planes are arrested by the (101-bar0) alumina plane. In this case, semi-coherent interfaces were observed along the grain boundary. It is verified that the bending strength increased in connection with the strain accumulation and amount of tetragonal structure
10. Attitude Strength.
Science.gov (United States)
Howe, Lauren C; Krosnick, Jon A
2017-01-03
Attitude strength has been the focus of a huge volume of research in psychology and related sciences for decades. The insights offered by this literature have tremendous value for understanding attitude functioning and structure and for the effective application of the attitude concept in applied settings. This is the first Annual Review of Psychology article on the topic, and it offers a review of theory and evidence regarding one of the most researched strength-related attitude features: attitude importance. Personal importance is attached to an attitude when the attitude is perceived to be relevant to self-interest, social identification with reference groups or reference individuals, and values. Attaching personal importance to an attitude causes crystallizing of attitudes (via enhanced resistance to change), effortful gathering and processing of relevant information, accumulation of a large store of well-organized relevant information in long-term memory, enhanced attitude extremity and accessibility, enhanced attitude impact on the regulation of interpersonal attraction, energizing of emotional reactions, and enhanced impact of attitudes on behavioral intentions and action. Thus, important attitudes are real and consequential psychological forces, and their study offers opportunities for addressing behavioral change.
11. Time-varying BRDFs.
Science.gov (United States)
Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter N; Nayar, Shree K
2007-01-01
The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.
12. Grain-orientation-dependent of γ–ε–α′ transformation and twinning in a super-high-strength, high ductility austenitic Mn-steel
Energy Technology Data Exchange (ETDEWEB)
Eskandari, M., E-mail: [email protected] [Department of Materials Science & Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz (Iran, Islamic Republic of); Zarei-Hanzaki, A. [Hot Deformation & Thermo-mechanical Processing of High Performance Engineering Materials, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Mohtadi-Bonab, M.A. [Department of Mechanical Engineering, University of Bonab, Velayat Highway (Iran, Islamic Republic of); Onuki, Y. [Frontier Research Center for Applied Atomic Sciences, Ibaraki University (Japan); Basu, R. [Department of Mechanical Engineering, ITM University, Gurgaon (India); Asghari, A. [Electrical and Computer Engineering Department, University of Texas at San Antonio, Texas (United States); Szpunar, J.A. [Advanced Materials for Clean Energy, Department of Mechanical Engineering, University of Saskatchewan (Canada)
2016-09-30
A newly developed, austenitic lightweight steel, containing a low-density element, Al, exhibits tensile elongation up to 50% as well as high ultimate-tensile stress (tensile fracture at 1800 MPa) without necking behavior. Electron backscatter diffraction analysis is carried out to investigate the orientation dependence of the martensitic transformation in tensile testing to 30% strain at 323 K (25 °C). A pronounced γ→ε→α′ transformation is observed in <111> and <110>∥TD (TD: tensile direction) γ-grains. The α′-transformation textures is analyzed. Large misorientation spreads is seen in the <100>∥TD γ-grains. Interestingly, twin-assisted martensitic transformation is detected in the <111>∥TD followed by the twin boundary directly moving to a γ/α′ phase boundary. These phenomena are related to a change of Schmid factor for different orientations of grains.
13. Suplementação de creatina e treinamento de força: alterações na resultante de força máxima dinâmica e variáveis antropométricas em universitários submetidos a oito semanas de treinamento de força (hipertrofia Creatine supplementation and strength training: alterations in the resultant of dynamic maximum strength and anthropometric variables in college students submitted to 8 weeks of strength training (hypertrophy
Directory of Open Access Journals (Sweden)
Tácito Pessoa de Souza Júnior
2007-10-01
Full Text Available OBJETIVO: Verificar as alterações promovidas pela suplementação de creatina nas variáveis antropométricas e da resultante de força máxima dinâmica (RFMD em universitários submetidos a oito semanas de treinamento de força. METODOLOGIA: Participaram deste estudo, 18 universitários do sexo masculino, com idade entre 19 e 25 anos. Antes do treinamento foram determinadas a estatura (cm, a massa corporal (kg e testes de ação muscular voluntária máxima dinâmica (1AMVMD, os sujeitos foram assinalados a um dos dois grupos, A (creatina e B (placebo, foi adotado o protocolo duplo-cego. Após oito semanas de treinamento de força, repetiu-se a bateria de testes do pré-treinamento. RESULTADOS: Após oito semanas, verificou-se que tanto no grupo A como no B houve alterações estatisticamente significantes (ES na RFMD em todos os exercícios (p = 0,007 a 0,008. A análise da melhora percentual e do delta da RFMD, nos exercícios de agachamento, desenvolvimento e supino fechado, mostrou que o grupo A teve alterações positivas ES superiores ao grupo B (p = 0,008 a 0,038. A massa magra aumentou ES somente no grupo A (p = 0,038. Contudo, o percentual de gordura corporal não mostrou alterações em nenhum dos grupos. A relação entre a melhora percentual (MP das circunferências (C do braço e antebraço e a MP na RFMD do exercício de desenvolvimento foi ES (r = 0,481 e 0,546, respectivamente, bem como entre a MP na C da coxa e na MP da RFMD do exercício de agachamento (r = 0,619. CONCLUSÃO: Independente do suplemento ingerido o treinamento de força foi capaz de induzir ajustes positivos na RFMD; contudo, a suplementação de creatina mostrou-se mais eficiente que o placebo, induzindo a maior aumento percentual e de delta na força.OBJECTIVE: To verify the alterations promoted by creatine supplementation in the anthropometric variables and the resultant of dynamic maximum strength (RDMS in college students submitted to 8 wk of strength
14. Bond strength of masonry
NARCIS (Netherlands)
Pluijm, van der R.; Vermeltfoort, A.Th.
1992-01-01
Bond strength is not a well defined property of masonry. Normally three types of bond strength can be distinguished: - tensile bond strength, - shear (and torsional) bond strength, - flexural bond strength. In this contribution the behaviour and strength of masonry in deformation controlled uniaxial
15. Varying Constants, Gravitation and Cosmology
Directory of Open Access Journals (Sweden)
Jean-Philippe Uzan
2011-03-01
Full Text Available Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.
16. varying elastic parameters distributions
KAUST Repository
Moussawi, Ali
2014-12-01
The experimental identication of mechanical properties is crucial in mechanics for understanding material behavior and for the development of numerical models. Classical identi cation procedures employ standard shaped specimens, assume that the mechanical elds in the object are homogeneous, and recover global properties. Thus, multiple tests are required for full characterization of a heterogeneous object, leading to a time consuming and costly process. The development of non-contact, full- eld measurement techniques from which complex kinematic elds can be recorded has opened the door to a new way of thinking. From the identi cation point of view, suitable methods can be used to process these complex kinematic elds in order to recover multiple spatially varying parameters through one test or a few tests. The requirement is the development of identi cation techniques that can process these complex experimental data. This thesis introduces a novel identi cation technique called the constitutive compatibility method. The key idea is to de ne stresses as compatible with the observed kinematic eld through the chosen class of constitutive equation, making possible the uncoupling of the identi cation of stress from the identi cation of the material parameters. This uncoupling leads to parametrized solutions in cases where 5 the solution is non-unique (due to unknown traction boundary conditions) as demonstrated on 2D numerical examples. First the theory is outlined and the method is demonstrated in 2D applications. Second, the method is implemented within a domain decomposition framework in order to reduce the cost for processing very large problems. Finally, it is extended to 3D numerical examples. Promising results are shown for 2D and 3D problems.
17. Corium crust strength measurements
Energy Technology Data Exchange (ETDEWEB)
Lomperski, S. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439-4840 (United States)], E-mail: [email protected]; Farmer, M.T. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439-4840 (United States)], E-mail: [email protected]
2009-11-15
Corium strength is of interest in the context of a severe reactor accident in which molten core material melts through the reactor vessel and collects on the containment basemat. Some accident management strategies involve pouring water over the melt to solidify it and halt corium/concrete interactions. The effectiveness of this method could be influenced by the strength of the corium crust at the interface between the melt and coolant. A strong, coherent crust anchored to the containment walls could allow the yet-molten corium to fall away from the crust as it erodes the basemat, thereby thermally decoupling the melt from the coolant and sharply reducing the cooling rate. This paper presents a diverse collection of measurements of the mechanical strength of corium. The data is based on load tests of corium samples in three different contexts: (1) small blocks cut from the debris of the large-scale MACE experiments, (2) 30 cm-diameter, 75 kg ingots produced by SSWICS quench tests, and (3) high temperature crusts loaded during large-scale corium/concrete interaction (CCI) tests. In every case the corium consisted of varying proportions of UO{sub 2}, ZrO{sub 2}, and the constituents of concrete to represent a LWR melt at different stages of a molten core/concrete interaction. The collection of data was used to assess the strength and stability of an anchored, plant-scale crust. The results indicate that such a crust is likely to be too weak to support itself above the melt. It is therefore improbable that an anchored crust configuration could persist and the melt become thermally decoupled from the water layer to restrict cooling and prolong an attack of the reactor cavity concrete.
18. Non-Uniform Compressive Strength of Debonded Sandwich Panels
DEFF Research Database (Denmark)
Nøkkentved, Alexandros; Lundsgaard-Larsen, Christian; Berggreen, Carl Christian
2005-01-01
debonds show a considerable strength reduction with increasing debond diameter, with failure mechanisms varying between fast debond propagation and wrinkling-introduced face compression failure for large and small debonds, respectively. Residual strength predictions are based on intact panel testing...
International Nuclear Information System (INIS)
Rimer, N.; Proffer, W.
1993-01-01
This presentation emphasizes the importance of a detailed description of the nonlinear deviatoric (strength) response of the surrounding rock in the numerical simulation of underground nuclear explosion phenomenology to the late times needed for test ban monitoring applications. We will show how numerical simulations which match ground motion measurements in volcanic tuffs and in granite use the strength values obtained from laboratory measurements on small core samples of these rocks but also require much lower strength values after the ground motion has interacted with the rock. The underlying physical mechanisms for the implied strength reduction are not yet well understood, and in fact may depend on the particular rock type. However, constitutive models for shock damage and/or effective stress have been used successfully at S-Cubed in both the Geophysics Program (primarily for DARPA) and the Containment Support Program (for DNA) to simulate late time ground motions measured at NTS in many different rock types
20. Effect of surface treatments on the bond strengths of facing composite resins to zirconia copings.
Science.gov (United States)
Tsumita, M; Kokubo, Y; Kano, T
2012-09-01
The present study evaluated and compared the bond strength between zirconia and facing composite resin using different surface conditioning methods before and after thermocycling. Four primers, three opaque resins, and two facing composite resins were used, and 10 surface treatment procedures were conducted. The bond strength was measured before and after 4,000 cycles of thermocycling. The mean values of each group were statistically analyzed using one-way analysis of variance (ANOVA). The bond strengths of facing composite resins to zirconia after various treatments varied depending on the primers, opaque resins, body resins, and thermocycling. The application of primers and opaque resins to the zirconia surface after sandblasting is expected to yield strong bond strength of the facing composite resin (Estenia CG&B) even after thermocycling.
1. A comparison of analysis methods to estimate contingency strength.
Science.gov (United States)
Lloyd, Blair P; Staubitz, Johanna L; Tapp, Jon T
2018-05-09
To date, several data analysis methods have been used to estimate contingency strength, yet few studies have compared these methods directly. To compare the relative precision and sensitivity of four analysis methods (i.e., exhaustive event-based, nonexhaustive event-based, concurrent interval, concurrent+lag interval), we applied all methods to a simulated data set in which several response-dependent and response-independent schedules of reinforcement were programmed. We evaluated the degree to which contingency strength estimates produced from each method (a) corresponded with expected values for response-dependent schedules and (b) showed sensitivity to parametric manipulations of response-independent reinforcement. Results indicated both event-based methods produced contingency strength estimates that aligned with expected values for response-dependent schedules, but differed in sensitivity to response-independent reinforcement. The precision of interval-based methods varied by analysis method (concurrent vs. concurrent+lag) and schedule type (continuous vs. partial), and showed similar sensitivities to response-independent reinforcement. Recommendations and considerations for measuring contingencies are identified. © 2018 Society for the Experimental Analysis of Behavior.
2. The Strength Compass
DEFF Research Database (Denmark)
Ledertoug, Mette Marie
In the Ph.D-project ͚Strengths-based Learning - Children͛s character strengths as a means to their learning potential͛ 750 Danish children have assessed ͚The Strength Compass͛ in order to identify their strengths and to create awareness of strengths. This was followed by a strengths......-based intervention program in order to explore the strengths. Finally different methods to apply the strength in everyday life at school were applied. The paper presentation will show the results for strengths display for children aged 6-16 in different categories: Different age groups: Are the same strengths...... present in both small children and youths? Gender: Do the results show differences between the two genders? Danish as a mother- tongue language: Do the results show any differences in the strengths display when considering different language and cultural backgrounds? Children with Special Needs: Do...
3. Computing Conditional VaR using Time-varying CopulasComputing Conditional VaR using Time-varying Copulas
Directory of Open Access Journals (Sweden)
Beatriz Vaz de Melo Mendes
2005-12-01
Full Text Available It is now widespread the use of Value-at-Risk (VaR as a canonical measure at risk. Most accurate VaR measures make use of some volatility model such as GARCH-type models. However, the pattern of volatility dynamic of a portfolio follows from the (univariate behavior of the risk assets, as well as from the type and strength of the associations among them. Moreover, the dependence structure among the components may change conditionally t past observations. Some papers have attempted to model this characteristic by assuming a multivariate GARCH model, or by considering the conditional correlation coefficient, or by incorporating some possibility for switches in regimes. In this paper we address this problem using time-varying copulas. Our modeling strategy allows for the margins to follow some FIGARCH type model while the copula dependence structure changes over time.
4. Nuclear threshold effects and neutron strength function
International Nuclear Information System (INIS)
Hategan, Cornel; Comisel, Horia
2003-01-01
One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)
5. The Importance of Muscular Strength: Training Considerations.
Science.gov (United States)
Suchomel, Timothy J; Nimphius, Sophia; Bellon, Christopher R; Stone, Michael H
2018-04-01
This review covers underlying physiological characteristics and training considerations that may affect muscular strength including improving maximal force expression and time-limited force expression. Strength is underpinned by a combination of morphological and neural factors including muscle cross-sectional area and architecture, musculotendinous stiffness, motor unit recruitment, rate coding, motor unit synchronization, and neuromuscular inhibition. Although single- and multi-targeted block periodization models may produce the greatest strength-power benefits, concepts within each model must be considered within the limitations of the sport, athletes, and schedules. Bilateral training, eccentric training and accentuated eccentric loading, and variable resistance training may produce the greatest comprehensive strength adaptations. Bodyweight exercise, isolation exercises, plyometric exercise, unilateral exercise, and kettlebell training may be limited in their potential to improve maximal strength but are still relevant to strength development by challenging time-limited force expression and differentially challenging motor demands. Training to failure may not be necessary to improve maximum muscular strength and is likely not necessary for maximum gains in strength. Indeed, programming that combines heavy and light loads may improve strength and underpin other strength-power characteristics. Multiple sets appear to produce superior training benefits compared to single sets; however, an athlete's training status and the dose-response relationship must be considered. While 2- to 5-min interset rest intervals may produce the greatest strength-power benefits, rest interval length may vary based an athlete's training age, fiber type, and genetics. Weaker athletes should focus on developing strength before emphasizing power-type training. Stronger athletes may begin to emphasize power-type training while maintaining/improving their strength. Future research should
6. The strength compass
DEFF Research Database (Denmark)
Ledertoug, Mette Marie
of agreement/disagreement. Also the child/teacher is asked whether the actual strength is important and if he or she has the possibilities to apply the strength in the school. In a PhDproject ‘Strengths-based Learning - Children’s Character Strengths as Means to their Learning Potential’ 750 Danish children......Individual paper presentation: The ‘Strength Compass’. The results of a PhDresearch project among schoolchildren (age 6-16) identifying VIAstrengths concerning age, gender, mother-tongue-langue and possible child psychiatric diagnosis. Strengths-based interventions in schools have a theoretical...... Psychological Publishing Company. ‘The Strength Compass’ is a computer/Ipad based qualitative tool to identify the strengths of a child by a self-survey or a teacher’s survey. It is designed as a visual analogue scale with a statement of the strength in which the child/teacher may declare the degree...
7. Impact of Hydrodynamics on Oral Biofilm Strength
NARCIS (Netherlands)
Paramonova, E.; Kalmykowa, O. J.; van der Mei, H. C.; Busscher, H. J.; Sharma, P. K.
2009-01-01
Mechanical removal of oral biofilms is ubiquitously accepted as the best way to prevent caries and periodontal diseases. Removal effectiveness strongly depends on biofilm strength. To investigate the influence of hydrodynamics on oral biofilm strength, we grew single- and multi-species biofilms of
8. Unexpected enhancements and reductions of rf spin resonance strengths
Directory of Open Access Journals (Sweden)
M. A. Leonova
2006-05-01
Full Text Available We recently analyzed all available data on spin-flipping stored beams of polarized protons, electrons, and deuterons. Fitting the modified Froissart-Stora equation to the measured polarization data after crossing an rf-induced spin resonance, we found 10–20-fold deviations from the depolarizing resonance strength equations used for many years. The polarization was typically manipulated by linearly sweeping the frequency of an rf dipole or rf solenoid through an rf-induced spin resonance; spin-flip efficiencies of up to 99.9% were obtained. The Lorentz invariance of an rf dipole’s transverse ∫Bdl and the weak energy dependence of its spin resonance strength E together imply that even a small rf dipole should allow efficient spin flipping in 100 GeV or even TeV storage rings; thus, it is important to understand these large deviations. Therefore, we recently studied the resonance strength deviations experimentally by varying the size and vertical betatron tune of a 2.1 GeV/c polarized proton beam stored in COSY. We found no dependence of E on beam size, but we did find almost 100-fold enhancements when the rf spin resonance was near an intrinsic spin resonance.
9. Strength and life under creeping
International Nuclear Information System (INIS)
Pospishil, B.
1982-01-01
Certain examples of the application of the Lepin modified creep model, which are of interest from technical viewpoint, are presented. Mathematical solution of the dependence of strength limit at elevated temperatures on creep characteristics is obtained. Tensile test at elevated temperatures is a particular case of creep or relaxation and both strength limit and conventional yield strength at elevated temperatures are completely determined by parameters of state equations during creep. The equation of fracture summing during creep is confirmed not only by the experiment data when stresses change sporadically, but also by good reflection of durability curve using the system of equations. The system presented on the basis of parameters of the equations obtained on any part of durability curve, permits to forecast the following parameters of creep: strain, strain rate, life time, strain in the process of fracture. Tensile test at elevated temperature is advisable as an addition when determining creep curves (time-strain curves) [ru
10. Strengths-based Learning
DEFF Research Database (Denmark)
Ledertoug, Mette Marie
-being. The Ph.D.-project in Strength-based learning took place in a Danish school with 750 pupils age 6-16 and a similar school was functioning as a control group. The presentation will focus on both the aware-explore-apply processes and the practical implications for the schools involved, and on measurable......Strength-based learning - Children͛s Character Strengths as Means to their Learning Potential͛ is a Ph.D.-project aiming to create a strength-based mindset in school settings and at the same time introducing strength-based interventions as specific tools to improve both learning and well...
11. Electronic Correlation Strength of Pu
DEFF Research Database (Denmark)
Svane, A.; C. Albers, R.; E. Christensen, N.
2013-01-01
A new electronic quantity, the correlation strength, is defined as a necessary step for understanding the properties and trends in strongly correlated electronic materials. As a test case, this is applied to the different phases of elemental Pu. Within the GW approximation we have surprisingly...... found a "universal" scaling relationship, where the f-electron bandwidth reduction due to correlation effects is shown to depend only upon the local density approximation (LDA) bandwidth and is otherwise independent of crystal structure and lattice constant....
12. Retrospective Attention Interacts with Stimulus Strength to Shape Working Memory Performance.
Science.gov (United States)
Wildegger, Theresa; Humphreys, Glyn; Nobre, Anna C
2016-01-01
Orienting attention retrospectively to selective contents in working memory (WM) influences performance. A separate line of research has shown that stimulus strength shapes perceptual representations. There is little research on how stimulus strength during encoding shapes WM performance, and how effects of retrospective orienting might vary with changes in stimulus strength. We explore these questions in three experiments using a continuous-recall WM task. In Experiment 1 we show that benefits of cueing spatial attention retrospectively during WM maintenance (retrocueing) varies according to stimulus contrast during encoding. Retrocueing effects emerge for supraliminal but not sub-threshold stimuli. However, once stimuli are supraliminal, performance is no longer influenced by stimulus contrast. In Experiments 2 and 3 we used a mixture-model approach to examine how different sources of error in WM are affected by contrast and retrocueing. For high-contrast stimuli (Experiment 2), retrocues increased the precision of successfully remembered items. For low-contrast stimuli (Experiment 3), retrocues decreased the probability of mistaking a target with distracters. These results suggest that the processes by which retrospective attentional orienting shape WM performance are dependent on the quality of WM representations, which in turn depends on stimulus strength during encoding.
13. Retrospective Attention Interacts with Stimulus Strength to Shape Working Memory Performance.
Directory of Open Access Journals (Sweden)
Theresa Wildegger
Full Text Available Orienting attention retrospectively to selective contents in working memory (WM influences performance. A separate line of research has shown that stimulus strength shapes perceptual representations. There is little research on how stimulus strength during encoding shapes WM performance, and how effects of retrospective orienting might vary with changes in stimulus strength. We explore these questions in three experiments using a continuous-recall WM task. In Experiment 1 we show that benefits of cueing spatial attention retrospectively during WM maintenance (retrocueing varies according to stimulus contrast during encoding. Retrocueing effects emerge for supraliminal but not sub-threshold stimuli. However, once stimuli are supraliminal, performance is no longer influenced by stimulus contrast. In Experiments 2 and 3 we used a mixture-model approach to examine how different sources of error in WM are affected by contrast and retrocueing. For high-contrast stimuli (Experiment 2, retrocues increased the precision of successfully remembered items. For low-contrast stimuli (Experiment 3, retrocues decreased the probability of mistaking a target with distracters. These results suggest that the processes by which retrospective attentional orienting shape WM performance are dependent on the quality of WM representations, which in turn depends on stimulus strength during encoding.
14. Reactive Strength Index: A Poor Indicator of Reactive Strength?
Science.gov (United States)
Healy, Robin; Kenny, Ian; Harrison, Drew
2017-11-28
The primary aim was to assess the relationships between reactive strength measures and associated kinematic and kinetic performance variables achieved during drop jumps. A secondary aim was to highlight issues with the use of reactive strength measures as performance indicators. Twenty eight national and international level sprinters, consisting of fourteen men and women, participated in this cross-sectional analysis. Athletes performed drop jumps from a 0.3 m box onto a force platform with dependent variables contact time (CT), landing time (TLand), push-off time (TPush), flight time (FT), jump height (JH), reactive strength index (RSI, calculated as JH / CT), reactive strength ratio (RSR, calculated as FT / CT) and vertical leg spring stiffness (Kvert) recorded. Pearson's correlation test found very high to near perfect relationships between RSI and RSR (r = 0.91 to 0.97), with mixed relationships found between RSI, RSR and the key performance variables, (Men: r = -0.86 to -0.71 between RSI/RSR and CT, r = 0.80 to 0.92 between RSI/RSR and JH; Women: r = -0.85 to -0.56 between RSR and CT, r = 0.71 between RSI and JH). This study demonstrates that the method of assessing reactive strength (RSI versus RSR) may be influenced by the performance strategies adopted i.e. whether an athlete achieves their best reactive strength scores via low CTs, high JHs or a combination. Coaches are advised to limit the variability in performance strategies by implementing upper and / or lower CT thresholds to accurately compare performances between individuals.
15. Plutonium (IV) complexation by nitrate in acid solutions of ionic strengths from 2 to 19 molal
International Nuclear Information System (INIS)
Berg, J.M.; Veirs, D.K.; Vaughn, R.B.; Cisneros, M.A.; Smith, C.A.
1997-01-01
Titrations of Pu(IV) with HNO 3 in a series of aqueous HClO 4 solutions ranging in ionic strength from 2 to 19 molal were followed using absorption spectrophotometry. The Pu 5f-5f spectra in the visible and near IR range change with complex formation. At each ionic strength, a series of spectra were obtained by varying nitrate concentration. Each series was deconvoluted into spectra f Pu 4+ (aq), Pu(NO 3 ) 3+ and Pu(NO 3 ) 2 2+ complexes, and simultaneously their formation constants were determined. When corrected for the incomplete dissociation of nitric acid, the ionic strength dependence of each formation constant can be described by two parameters, β 0 and Δ var-epsilon using the formulae of specific ion interaction theory. The difficulties with extending this analysis to higher nitrate coordination numbers are discussed
16. Fault roughness and strength heterogeneity control earthquake size and stress drop
KAUST Repository
Zielke, Olaf
2017-01-13
An earthquake\\'s stress drop is related to the frictional breakdown during sliding and constitutes a fundamental quantity of the rupture process. High-speed laboratory friction experiments that emulate the rupture process imply stress drop values that greatly exceed those commonly reported for natural earthquakes. We hypothesize that this stress drop discrepancy is due to fault-surface roughness and strength heterogeneity: an earthquake\\'s moment release and its recurrence probability depend not only on stress drop and rupture dimension but also on the geometric roughness of the ruptured fault and the location of failing strength asperities along it. Using large-scale numerical simulations for earthquake ruptures under varying roughness and strength conditions, we verify our hypothesis, showing that smoother faults may generate larger earthquakes than rougher faults under identical tectonic loading conditions. We further discuss the potential impact of fault roughness on earthquake recurrence probability. This finding provides important information, also for seismic hazard analysis.
17. Eestlased Karlovy Varys / J. R.
Index Scriptorium Estoniae
J. R.
2007-01-01
Ilmar Raagi mängufilm "Klass" osaleb 42. Karlovy Vary rahvusvahelise filmifestivali võistlusprogrammis "East of the West" ja Asko Kase lühimängufilm "Zen läbi prügi" on valitud festivali kõrvalprogrammi "Forum of Independents"
18. Esmaklassiline Karlovy Vary / Jaanus Noormets
Index Scriptorium Estoniae
Noormets, Jaanus
2007-01-01
Ilmar Raagi mängufilm "Klass" võitis 42. Karlovy Vary rahvusvahelise filmifestivalil kaks auhinda - ametliku kõrvalvõistlusprogrammi "East of the West" eripreemia "Special mention" ja Euroopa väärtfilmikinode keti Europa Cinemas preemia. Ka Asko Kase lühifilmi "Zen läbi prügi linastumisest ning teistest auhinnasaajatest ning osalejatest
19. Optimistlik Karlovy Vary / Jaan Ruus
Index Scriptorium Estoniae
Ruus, Jaan, 1938-2017
2007-01-01
42. Karlovy Vary rahvusvahelise filmifestivali auhinnatud filmidest (žürii esimees Peter Bart). Kristallgloobuse sai Islandi-Saksamaa "Katseklaasilinn" (režii Baltasar Kormakur), parimaks režissööriks tunnistati norralane Bard Breien ("Negatiivse mõtlemise kunst"). Austraallase Michael James Rowlandi "Hea õnne teekond" sai žürii eripreemia
20. Influence of porosity and groundmass crystallinity on dome rock strength: a case study from Mt. Taranaki, New Zealand
Science.gov (United States)
Zorn, Edgar U.; Rowe, Michael C.; Cronin, Shane J.; Ryan, Amy G.; Kennedy, Lori A.; Russell, James K.
2018-04-01
Lava domes pose a significant hazard to infrastructure, human lives and the environment when they collapse. Their stability is partly dictated by internal mechanical properties. Here, we present a detailed investigation into the lithology and composition of a Rocks with variable porosity and groundmass crystallinity were compared using measured compressive and tensile strength, derived from deformation experiments performed at room temperature and low (3 MPa) confining pressures. Based on data obtained, porosity exerts the main control on rock strength and mode of failure. High porosity (> 23%) rocks show low rock strength (rocks (5-23%) exhibit higher measured rock strengths (up to 278 MPa) and brittle failure. Groundmass crystallinity, porosity and rock strength are intercorrelated. High groundmass crystal content is inversely related to low porosity, implying crystallisation and degassing of a slowly undercooled magma that experienced rheological stiffening under high pressures deeper within the conduit. This is linked to a slow magma ascent rate and results in a lava dome with higher rock strength. Samples with low groundmass crystallinity are associated with higher porosity and lower rock strength, and represent magma that ascended more rapidly, with faster undercooling, and solidification in the upper conduit at low pressures. Our experimental results show that the inherent strength of rocks within a growing dome may vary considerably depending on ascent/emplacement rates, thus significantly affecting dome stability and collapse hazards.
1. Give Me Strength.
Institute of Scientific and Technical Information of China (English)
维拉
1996-01-01
Mort had an absolutely terrible day at the office.Everythingthat could go wrong did go wrong.As he walked home he could beheard muttering strange words to himself:“Oh,give me strength,give me strength.”Mort isn’t asking for the kind of strength thatbuilds strong muscles:he’s asking for the courage or ability to
2. Spall behavior of cast iron with varying microstructures
International Nuclear Information System (INIS)
Plume, Gifford; Rousseau, Carl-Ernst
2014-01-01
The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94–1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.
3. Spall behavior of cast iron with varying microstructures
Energy Technology Data Exchange (ETDEWEB)
Plume, Gifford; Rousseau, Carl-Ernst, E-mail: [email protected] [Mechanical Engineering, University of Rhode Island, 92 Upper College Rd., Kingston, Rhode Island 02881 (United States)
2014-07-21
The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94–1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.
4. Genetic polymorphisms in varied environments.
Science.gov (United States)
Powell, J R
1971-12-03
Thirteen experimenital populationis of Drosophila willistoni were maintained in cages, in some of which the environments were relatively constant and in others varied. After 45 weeks, the populations were assayed by gel electrophoresis for polymorphisms at 22 protein loci. The average heterozygosity per individual and the average unmber of alleles per locus were higher in populations maintained in heterogeneous environments than in populations in more constant enviroments.
5. Inverse problemfor an inhomogeneous elastic beam at a combined strength
Directory of Open Access Journals (Sweden)
2014-01-01
Full Text Available In the article the authors describe a method of optimizing the stress state of an elastic beam, subject to the simultaneous action of the central concentrated force and bending moment. The optimization method is based on solving the inverse problem of the strength of materials, consisting in defining the law of changing in elasticity modulus with beam cross-section altitude. With this changing the stress state will be preset. Most problems of the elasticity theory of inhomogeneous bodies are solved in direct formulation, the essence of which is to determine the stress-strain state of a body at the known dependences of the material elastic characteristics from the coordinates. There are also some solutions of the inverse problems of the elasticity theory, in which the dependences of the mechanical characteristics from the coordinates, at which the stress state of a body is preset, are determined. In the paper the authors solve the problem of finding a dependence modulus of elasticity, where the stresses will be constant over the beam’s cross section. We will solve the problem of combined strength (in the case of the central stretching and bending. We will use an iterative method. As the initial solution, we take the solution for a homogeneous material. As the first approximation, we consider the stress state of a beam, when the modulus of elasticity varies linearly. According to the results, it can be stated that three approximations are sufficient in the considered problem. The obtained results allow us to use them in assessing the strength of a beam and its optimization.
Directory of Open Access Journals (Sweden)
Michal Mathias
2015-01-01
Full Text Available The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw and the Joint Research Centre (JRC in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.
7. High strength ferritic alloy
International Nuclear Information System (INIS)
1977-01-01
A high strength ferritic steel is specified in which the major alloying elements are chromium and molybdenum, with smaller quantities of niobium, vanadium, silicon, manganese and carbon. The maximum swelling is specified for various irradiation conditions. Rupture strength is also specified. (U.K.)
8. Photon strength functions
International Nuclear Information System (INIS)
Bergqvist, I.
1976-01-01
Methods for extracting photon strength functions are briefly discussed. We follow the Brink-Axel approach to relate the strength functions to the giant resonances observed in photonuclear work and summarize the available data on the E1, E2 and M1 resonances. Some experimental and theoretical problems are outlined. (author)
9. Interviewing to Understand Strengths
Science.gov (United States)
Hass, Michael R.
2018-01-01
Interviewing clients about their strengths is an important part of developing a complete understanding of their lives and has several advantages over simply focusing on problems and pathology. Prerequisites for skillfully interviewing for strengths include the communication skills that emerge from a stance of not knowing, developing a vocabulary…
10. Imaging Shear Strength Along Subduction Faults
Science.gov (United States)
Bletery, Quentin; Thomas, Amanda M.; Rempel, Alan W.; Hardebeck, Jeanne L.
2017-11-01
Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.
11. Imaging shear strength along subduction faults
Science.gov (United States)
Bletery, Quentin; Thomas, Amanda M.; Rempel, Alan W.; Hardebeck, Jeanne L.
2017-01-01
Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.
12. New varying speed of light theories
CERN Document Server
Magueijo, J
2003-01-01
We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying $c$, dispelling the myth that the constancy of $c$ is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a color dependent speed of light; varying $c$ induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how doubly special'' relativity has emerged as a VSL effective model of quantum space...
13. Size effects in olivine control strength in low-temperature plasticity regime
Science.gov (United States)
Kumamoto, K. M.; Thom, C.; Wallis, D.; Hansen, L. N.; Armstrong, D. E. J.; Goldsby, D. L.; Warren, J. M.; Wilkinson, A. J.
2017-12-01
The strength of the lithospheric mantle during deformation by low-temperature plasticity controls a range of geological phenomena, including lithospheric-scale strain localization, the evolution of friction on deep seismogenic faults, and the flexure of tectonic plates. However, constraints on the strength of olivine in this deformation regime are difficult to obtain from conventional rock-deformation experiments, and previous results vary considerably. We demonstrate via nanoindentation that the strength of olivine in the low-temperature plasticity regime is dependent on the length-scale of the test, with experiments on smaller volumes of material exhibiting larger yield stresses. This "size effect" has previously been explained in engineering materials as a result of the role of strain gradients and associated geometrically necessary dislocations in modifying plastic behavior. The Hall-Petch effect, in which a material with a small grain size exhibits a higher strength than one with a large grain size, is thought to arise from the same mechanism. The presence of a size effect resolves discrepancies among previous experimental measurements of olivine, which were either conducted using indentation methods or were conducted on polycrystalline samples with small grain sizes. An analysis of different low-temperature plasticity flow laws extrapolated to room temperature reveals a power-law relationship between length-scale (grain size for polycrystalline deformation and contact radius for indentation tests) and yield strength. This suggests that data from samples with large inherent length scales best represent the plastic strength of the coarse-grained lithospheric mantle. Additionally, the plastic deformation of nanometer- to micrometer-sized asperities on fault surfaces may control the evolution of fault roughness due to their size-dependent strength.
14. Strength and structure of nanocrystalline titanium
International Nuclear Information System (INIS)
Noskova, N.I.; Pereturina, I.A.; Elkina, O.A.; Stolyarov, V.V.
2004-01-01
Investigation results on strength and plasticity of nanocrystalline titanium VT-1 are presented. Specific features of plastic deformation on tension of this material specimens in an electron microscope column are studied in situ. It is shown that nanocrystalline titanium strength and plasticity at room temperature are dependent on the structure and nanograin size. It is revealed that deformation processes in nanocrystalline titanium are characterized by activation of deformation rotational modes and microtwinning [ru
15. New varying speed of light theories
International Nuclear Information System (INIS)
Magueijo, Joao
2003-01-01
We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying-c, dispelling the myth that the constancy of c is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a colour-dependent speed of light; varying-c induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how 'doubly special' relativity has emerged as a VSL effective model of quantum space-time, with observational implications for ultra-high energy cosmic rays (UHECRs) and gamma ray bursts. Some recent work on the physics of 'black' holes and other compact objects in VSL theories is also described, highlighting phenomena associated with spatial (as opposed to temporal) variations in c. Finally, we describe the observational status of the theory. The evidence is currently slim-redshift dependence in the atomic fine structure, anomalies with UHECRs, and (to a much lesser extent) the acceleration of the universe and the WMAP data. The constraints (e.g. those arising from nucleosynthesis or geological bounds) are tight but not insurmountable. We conclude with the observational predictions of the theory and the prospects for its refutation or vindication
16. Estimating varying coefficients for partial differential equation models.
Science.gov (United States)
Zhang, Xinyu; Cao, Jiguo; Carroll, Raymond J
2017-09-01
Partial differential equations (PDEs) are used to model complex dynamical systems in multiple dimensions, and their parameters often have important scientific interpretations. In some applications, PDE parameters are not constant but can change depending on the values of covariates, a feature that we call varying coefficients. We propose a parameter cascading method to estimate varying coefficients in PDE models from noisy data. Our estimates of the varying coefficients are shown to be consistent and asymptotically normally distributed. The performance of our method is evaluated by a simulation study and by an empirical study estimating three varying coefficients in a PDE model arising from LIDAR data. © 2017, The International Biometric Society.
17. Measuring Relative Coupling Strength in Circadian Systems.
Science.gov (United States)
Schmal, Christoph; Herzog, Erik D; Herzel, Hanspeter
2018-02-01
Modern imaging techniques allow the monitoring of circadian rhythms of single cells. Coupling between these single cellular circadian oscillators can generate coherent periodic signals on the tissue level that subsequently orchestrate physiological outputs. The strength of coupling in such systems of oscillators is often unclear. In particular, effects on coupling strength by varying cell densities, by knockouts, and by inhibitor applications are debated. In this study, we suggest to quantify the relative coupling strength via analyzing period, phase, and amplitude distributions in ensembles of individual circadian oscillators. Simulations of different oscillator networks show that period and phase distributions become narrower with increasing coupling strength. Moreover, amplitudes can increase due to resonance effects. Variances of periods and phases decay monotonically with coupling strength, and can serve therefore as measures of relative coupling strength. Our theoretical predictions are confirmed by studying recently published experimental data from PERIOD2 expression in slices of the suprachiasmatic nucleus during and after the application of tetrodotoxin (TTX). On analyzing the corresponding period, phase, and amplitude distributions, we can show that treatment with TTX can be associated with a reduced coupling strength in the system of coupled oscillators. Analysis of an oscillator network derived directly from the data confirms our conclusions. We suggest that our approach is also applicable to quantify coupling in fibroblast cultures and hepatocyte networks, and for social synchronization of circadian rhythmicity in rodents, flies, and bees.
18. Investigation of the shear bond strength to dentin of universal adhesives applied with two different techniques
Directory of Open Access Journals (Sweden)
Elif Yaşa
2017-09-01
Full Text Available Objective: The aim of this study was to evaluate the shear bond strength of universal adhesives applied with self-etch and etch&rinse techniques to dentin. Materials and Method: Fourty-eight sound extracted human third molars were used in this study. Occlusal enamel was removed in order to expose the dentinal surface, and the surface was flattened. Specimens were randomly divided into four groups and were sectioned vestibulo-lingually using a diamond disc. The universal adhesives: All Bond Universal (Group 1a and 1b, Gluma Bond Universal (Group 2a and 2b and Single Bond Universal (Group 3a and 3b were applied onto the tooth specimens either with self-etch technique (a or with etch&rinse technique (b according to the manufacturers’ instructions. Clearfil SE Bond (Group 4a; self-etch and Optibond FL (Group 4b; etch&rinse were used as control groups. Then the specimens were restored with a nanohybrid composite resin (Filtek Z550. After thermocycling, shear bond strength test was performed with a universal test machine at a crosshead speed of 0.5 mm/min. Fracture analysis was done under a stereomicroscope (×40 magnification. Data were analyzed using two-way ANOVA and post-hoc Tukey tests. Results: Statistical analysis showed significant differences in shear bond strength values between the universal adhesives (p<0.05. Significantly higher bond strength values were observed in self-etch groups (a in comparison to etch&rinse groups (b (p<0.05. Among all groups, Single Bond Universal showed the greatest shear bond strength values, whereas All Bond Universal showed the lowest shear bond strength values with both application techniques. Conclusion: Dentin bonding strengths of universal adhesives applied with different techniques may vary depending on the adhesive material. For the universal bonding agents tested in this study, the etch&rinse technique negatively affected the bond strength to dentin.
19. Time Varying Market Integration and Expected Rteurns in Emerging Markets
NARCIS (Netherlands)
de Jong, F.C.J.M.; de Roon, F.A.
2001-01-01
We use a simple model in which the expected returns in emerging markets depend on their systematic risk as measured by their beta relative to the world portfolio as well as on the level of integration in that market.The level of integration is a time-varying variable that depends on the market value
20. Weighted approximation with varying weight
CERN Document Server
Totik, Vilmos
1994-01-01
A new construction is given for approximating a logarithmic potential by a discrete one. This yields a new approach to approximation with weighted polynomials of the form w"n"(" "= uppercase)P"n"(" "= uppercase). The new technique settles several open problems, and it leads to a simple proof for the strong asymptotics on some L p(uppercase) extremal problems on the real line with exponential weights, which, for the case p=2, are equivalent to power- type asymptotics for the leading coefficients of the corresponding orthogonal polynomials. The method is also modified toyield (in a sense) uniformly good approximation on the whole support. This allows one to deduce strong asymptotics in some L p(uppercase) extremal problems with varying weights. Applications are given, relating to fast decreasing polynomials, asymptotic behavior of orthogonal polynomials and multipoint Pade approximation. The approach is potential-theoretic, but the text is self-contained.
1. Estrelas variáveis
OpenAIRE
Viana, Sérgio Manuel de Oliveira
2001-01-01
A observação do céu nocturno é uma prática que vem da Antiguidade. Desde então e durante muito tempo pensou-se que as estrelas mantinham o brilho constante. Assim foi até ao século XVI, quando David Fabricius observou uma estrela cujo brilho variava periodicamente. Dois séculos mais tarde, Jonh Goodricke descobriu uma segunda estrela e com o desenvolvimento de instrumentos de observação este conjunto foi muito alargado e hoje inclui o Sol.A variação do brilho das estrelas variáveis permite d...
2. The strength research of the adhesive joints of sheet structures ...
African Journals Online (AJOL)
The research results of stress-strained condition of constructional sheet materials are given in the article. The strength dependence on type, configuration and sizes of adhesive joints is analyzed. The research of the strength dependence was made on the samples from bakelite plywood with the main types of adhesive joints ...
3. Ballistic performance of a Kevlar-29 woven fibre composite under varied temperatures
Science.gov (United States)
Soykasap, O.; Colakoglu, M.
2010-05-01
Armours are usually manufactured from polymer matrix composites and used for both military and non-military purposes in different seasons, climates, and regions. The mechanical properties of the composites depend on temperature, which also affects their ballistic characteristics. The armour is used to absorb the kinetic energy of a projectile without any major injury to a person. Therefore, besides a high strength and lightness, a high damping capacity is required to absorb the impact energy transferred by the projectile. The ballistic properties of a Kevlar 29/polyvinyl butyral composite are investigated under varied temperatures in this study. The elastic modulus of the composite is determined from the natural frequency of composite specimens at different temperatures by using a damping monitoring method. Then, the backside deformation of composite plates is analysed experimentally and numerically employing the finite-element program Abaqus. The experimental and numeric results obtained are in good agreement.
4. Magnetic resonance imaging: effects of magnetic field strength
International Nuclear Information System (INIS)
Crooks, L.E.; Arakawa, M.; Hoenninger, J.; McCarten, B.; Watts, J.; Kaufman, L.
1984-01-01
Magnetic resonance images of the head, abdomen, and pelvis of normal adult men were obtained using varying magnetic field strength, and measurements of T1 and T2 relaxations and of signal-to-noise (SN) ratios were determined. For any one spin echo sequence, gray/white matter contrast decreases and muscle/fat contrast increases with field. SN levels rise rapidly up to 3.0 kgauss and then change more slowly, actually dropping for muscle. The optimum field for magnetic resonance imaging depends on tissue type, body part, and imaging sequence, so that it does not have a unique value. Magnetic resonance systems that operate in the 3.0-5.0 kgauss range achieve most or all of the gains that can be achieved by higher magnetic fields
5. Anistropically varying conductivity in irreversible electroporation simulations.
Science.gov (United States)
Labarbera, Nicholas; Drapaca, Corina
2017-11-01
One recent area of cancer research is irreversible electroporation (IRE). Irreversible electroporation is a minimally invasive procedure where needle electrodes are inserted into the body to ablate tumor cells with electricity. The aim of this paper is to propose a mathematical model that incorporates a tissue's conductivity increasing more in the direction of the electrical field as this has been shown to occur in experiments. It was necessary to mathematically derive a valid form of the conductivity tensor such that it is dependent on the electrical field direction and can be easily implemented into numerical software. The derivation of a conductivity tensor that can take arbitrary functions for the conductivity in the directions tangent and normal to the electrical field is the main contribution of this paper. Numerical simulations were performed for isotropic-varying and anisotropic-varying conductivities to evaluate the importance of including the electrical field's direction in the formulation for conductivity. By starting from previously published experimental results, this paper derived a general formulation for an anistropic-varying tensor for implementation into irreversible electroporation modeling software. The anistropic-varying tensor formulation allows the conductivity to take into consideration both electrical field direction and magnitude, as opposed to previous published works that only took into account electrical field magnitude. The anisotropic formulation predicts roughly a five percent decrease in ablation size for the monopolar simulation and approximately a ten percent decrease in ablation size for the bipolar simulations. This is a positive result as previously reported results found the isotropic formulation to overpredict ablation size for both monopolar and bipolar simulations. Furthermore, it was also reported that the isotropic formulation overpredicts the ablation size more for the bipolar case than the monopolar case. Thus, our
6. Large quantum dots with small oscillator strength
DEFF Research Database (Denmark)
Stobbe, Søren; Schlereth, T.W.; Höfling, S.
2010-01-01
We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots...... is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size assuming a quantum-dot confinement given by a parabolic in-plane potential and a hard-wall vertical potential and predict a very large...... intermixing inside the quantum dots....
7. Development of K-Basin High-Strength Homogeneous Sludge Simulants and Correlations Between Unconfined Compressive Strength and Shear Strength
Energy Technology Data Exchange (ETDEWEB)
Onishi, Yasuo; Baer, Ellen BK; Chun, Jaehun; Yokuda, Satoru T.; Schmidt, Andrew J.; Sande, Susan; Buchmiller, William C.
2011-02-20
potential for erosion, it is important to compare the measured shear strength to penetrometer measurements and to develop a correlation (or correlations) between UCS measured by a pocket penetrometer and direct shear strength measurements for various homogeneous and heterogeneous simulants. This study developed 11 homogeneous simulants, whose shear strengths vary from 4 to 170 kPa. With these simulants, we developed correlations between UCS measured by a Geotest E-280 pocket penetrometer and shear strength values measured by a Geonor H-60 hand-held vane tester and a more sophisticated bench-top unit, the Haake M5 rheometer. This was achieved with side-by-side measurements of the shear strength and UCS of the homogeneous simulants. The homogeneous simulants developed under this study consist of kaolin clay, plaster of Paris, and amorphous alumina CP-5 with water. The simulants also include modeling clay. The shear strength of most of these simulants is sensitive to various factors, including the simulant size, the intensity of mixing, and the curing time, even with given concentrations of simulant components. Table S.1 summarizes these 11 simulants and their shear strengths.
8. Nutritional Supplements for Strength Power Athletes
Science.gov (United States)
Wilborn, Colin
Over the last decade research involving nutritional supplementation and sport performance has increased substantially. Strength and power athletes have specific needs to optimize their performance. Nutritional supplementation cannot be viewed as a replacement for a balanced diet but as an important addition to it. However, diet and supplementation are not mutually exclusive, nor does one depend on the other. Strength and power athletes have four general areas of supplementation needs. First, strength athletes need supplements that have a direct effect on performance. The second group of supplements includes those that promote recovery. The third group comprises the supplements that enhance immune function. The last group of supplements includes those that provide energy or have a direct effect on the workout. This chapter reviews the key supplements needed to optimize the performance and training of the strength athlete.
9. Strength and power of knee extensor muscles
Directory of Open Access Journals (Sweden)
Knežević Olivera
2011-01-01
Full Text Available In the studies of human neuromuscular function, the function of leg muscles has been most often measured, particularly the function of the knee extensors. Therefore, this review will be focused on knee extensors, methods for assessment of its function, the interdependence of strength and power, relations that describe these two abilities and the influence of various factors on their production (resistance training, stretching, movement tasks, age, etc.. Given that it consists of four separate muscles, the variability of their anatomical characteristics affects their participation in strength and power production, depending on the type of movement and motion that is performed. Since KE is active in a variety of activities it must be able to generate great strength in a large and diverse range of muscle lengths and high shortening velocities, in respect to different patterns of strength production, and thus different generation capacities within the muscle (Blazevich et al., 2006. It has been speculated that KE exerts its Pmax at workloads close to subject's own body weight or lower (Rahmani et al., 2001, which is very close to the maximum dynamic output hypothesis (MDI of Jaric and Markovic (2009. Changes under the influence of resistance training or biological age are variously manifested in muscle's morphological, physiological and neural characteristics, and thus in strength and power. Understanding the issues related to strength and power as abilities of great importance for daily activities, is also important for sports and rehabilitation. Performances improvement in sports in which leg muscles strength and power are crucial, as well as recovery after the injuries, are largely dependent on the research results regarding KE function. Also, the appropriate strength balance between knee flexors and extensors is important for the knee joint stability, so that the presence of imbalance between these two muscle groups might be a risk factor for
10. Strength of Fibrous Composites
CERN Document Server
Huang, Zheng-Ming
2012-01-01
"Strength of Fibrous Composites" addresses evaluation of the strength of a fibrous composite by using its constituent material properties and its fiber architecture parameters. Having gone through the book, a reader is able to predict the progressive failure behavior and ultimate strength of a fibrous laminate subjected to an arbitrary load condition in terms of the constituent fiber and matrix properties, as well as fiber geometric parameters. The book is useful to researchers and engineers working on design and analysis for composite materials. Dr. Zheng-Ming Huang is a professor at the School of Aerospace Engineering & Applied Mechanics, Tongji University, China. Mr. Ye-Xin Zhou is a PhD candidate at the Department of Mechanical Engineering, the University of Hong Kong, China.
11. Compressive strain-dependent bending strength property of Al{sub 2}O{sub 3}-ZrO{sub 2} (1.5 mol% Y{sub 2}O{sub 3}) composites performance by HIP
Energy Technology Data Exchange (ETDEWEB)
Reyes-Rojas, A. [Centro de Investigacion en Materiales Avanzados S.C. (CIMAV), Miguel de Cervantes 120, Complejo Industrial Chihuahua, Cd. de Chihuahua, Chihuahua (Mexico)], E-mail: [email protected]; Esparza-Ponce, H. [Centro de Investigacion en Materiales Avanzados S.C. (CIMAV), Miguel de Cervantes 120, Complejo Industrial Chihuahua, Cd. de Chihuahua, Chihuahua (Mexico); De la Torre, S.D. [Centro de Investigacion e Innovacion Tecnologica (CIITEC)-IPN, D.F. Mexico (Mexico); Torres-Moye, E. [Centro de Investigacion en Materiales Avanzados S.C. (CIMAV), Miguel de Cervantes 120, Complejo Industrial Chihuahua, Cd. de Chihuahua, Chihuahua (Mexico)
2009-04-15
Nanometric powders and sintered ceramics of Al{sub 2}O{sub 3}-ZrO{sub 2} (1.5 mol% Y{sub 2}O{sub 3}) prepared by hot isostatic pressing HIP have been studied. A detailed crystallographic study has been performed through X-ray diffraction, Williamson-Hall method, Rietveld method and high-resolution electron microscopy HREM analysis. The crystallographic structure data, such as domain size, lattice parameters, wt% phase, and micro-strain direction have been obtained using Rietveld refinement and Williamson-Hall methods. The results revealed that the compressive strain ({epsilon}) increased from 0.56 to 1.18 (10{sup -3}) as the t-ZrO{sub 2} content increased too. The HREM interface study conducted along the [0 0 0 1]Al{sub 2}O{sub 3}||[0 0 1]ZrO{sub 2} zone axis revealed a micro-strain lattice distortion accumulated at the grain boundary due to the ZrO{sub 2} martensitic phase transformation on cooling, t-ZrO{sub 2} grains coalescence and to the grain growth of {alpha}-Al{sub 2}O{sub 3} which cause elongated tetragonal crystals. Micro-strain lattice distortion is adjusted by the shear displacements of the planes (1 1 0) and (11-bar0) along [1-bar10] and [1-bar1-bar0] crystallographic directions, respectively; these planes are arrested by the (101-bar0) alumina plane. In this case, semi-coherent interfaces were observed along the grain boundary. It is verified that the bending strength increased in connection with the strain accumulation and amount of tetragonal structure.
12. A mechanistic analysis of density dependence in algal population dynamics
Directory of Open Access Journals (Sweden)
2015-04-01
Full Text Available Population density regulation is a fundamental principle in ecology, but the specific process underlying functional expression of density dependence remains to be fully elucidated. One view contends that patterns of density dependence are largely fixed across a species irrespective of environmental conditions, whereas another is that the strength and expression of density dependence are fundamentally variable depending on the nature of exogenous or endogenous constraints acting on the population. We conducted a study investigating the expression of density dependence in Chlamydomonas spp. grown under a gradient from low to high nutrient density. We predicted that the relationship between per capita growth rate (pgr and population density would vary from concave up to concave down as nutrient density became less limiting and populations experienced weaker density regulation. Contrary to prediction, we found that the relationship between pgr and density became increasingly concave-up as nutrient levels increased. We also found that variation in pgr increased, and pgr levels reached higher maxima in nutrient-limited environments. Most likely, these results are attributable to population growth suppression in environments with high intraspecific competition due to limited nutrient resources. Our results suggest that density regulation is strongly variable depending on exogenous and endogenous processes acting on the population, implying that expression of density dependence depends extensively on local conditions. Additional experimental work should reveal the mechanisms influencing how the expression of density dependence varies across populations through space and time.
13. An overview of strength training injuries: acute and chronic.
Science.gov (United States)
Lavallee, Mark E; Balam, Tucker
2010-01-01
This article introduces the history of strength training, explains the many different styles of strength training, and discusses common injuries specific to each style. Strength training is broken down into five disciplines: basic strength or resistance training, bodybuilding, power lifting, style-dependant strength sports (e.g., strongman competitions, Highland games, field events such as shot put, discus, hammer throw, and javelin), and Olympic-style weightlifting. Each style has its own principal injuries, both acute and chronic, related to the individual technique. Acute injuries should be further categorized as emergent or nonemergent. Specific age-related populations (i.e., the very young and the aging athlete) carry additional considerations.
14. The correlation between sports results in swimming and general and special muscle strength
Directory of Open Access Journals (Sweden)
Wioletta Lubkowska
2017-12-01
Full Text Available Introduction. Swimming as a sport encompasses various styles and distances (from 50 up to 1,500 meters. The correlation between sports results and general/special muscle strength seems unquestionable. Aim. The purpose of this paper is to answer the question related to maintaining the proportion between muscle strength development (which depends mainly on land-based trainings and endurance trainings in water. Material and methods. The study covered 14 leading swimmers from MKP Szczecin who specialized mainly in short and medium distances; they were members of the national senior and junior teams in the 2013/14 training year. The general strength tests were conducted at the beginning and at the end of the winter and summer preparatory periods. The following tests were performed: bench-pressing, pull-ups and bar dips. At the end of the main research period, a thrust test was conducted on land (on a swim bench, as well as a thrust test in the water. Results. All participants demonstrated progress in results between the summer season and the winter season. The range of training loads was higher in the summer due to the length of preparation (by about 100%. The individual progress was, however, very varied. Conclusions. The level of sports progress achieved by individual swimmers was greatly diversified. The relatively high level of general and special strength in the tested swimmers was linked to their need to display these motor skills while swimming. Subjects who showed the greatest progress in the general and special strength trials, displayed the biggest improvement in their swimming performance during the competition season. Swimmers with a fairly high level of strength, but a moderate sports level should analyze and improve their swimming technique. Subjects whose progress in general and special strength tests was the least significant, should try and achieve progress by developing other technical and coordination skills.
15. High strength alloys
Science.gov (United States)
Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX
2010-08-31
High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.
16. Hand grip strength
DEFF Research Database (Denmark)
Frederiksen, Henrik; Gaist, David; Petersen, Hans Christian
2002-01-01
in life is a major problem in terms of prevalence, morbidity, functional limitations, and quality of life. It is therefore of interest to find a phenotype reflecting physical functioning which has a relatively high heritability and which can be measured in large samples. Hand grip strength is known......-55%). A powerful design to detect genes associated with a phenotype is obtained using the extreme discordant and concordant sib pairs, of whom 28 and 77 dizygotic twin pairs, respectively, were found in this study. Hence grip strength is a suitable phenotype for identifying genetic variants of importance to mid...
17. Effect of ionic strength on the kinetics of ionic and micellar reactions in aqueous solution
International Nuclear Information System (INIS)
Dung, M.H.; Kozak, J.J.
1982-01-01
The effect of electrostatic forces on the rate of reaction between ions in aqueous solutions of intermediate ionic strength is studied in this paper. We consider the kinetics of reactions involving simple ionic species (1--1 and 2--2 electrolyte systems) as well as kinetic processes mediated by the presence of micellar ions (or other charged organizates). In the regime of ionic strength considered, dielectric saturation of the solvent in the vicinity of the reacting ions must be taken into account and this is done by introducing several models to describe the recovery of the solvent from saturation to its continuum dielectric behavior. To explore the effects of ion size, charge number, and ionic strength on the overall rate constant for the process considered, we couple the traditional theory of ionic reactions in aqueous solution with calculations of the electrostatic potential obtained via solution of the nonlinear Poisson--Boltzmann equation. The great flexibility of the nonlinear Poisson--Boltzmann theory allows us to explore quantitatively the influence of each of these effects, and our simulations show that the short-range properties of the electrostatic potential affect primarily kinetically controlled processes (to varying degrees, depending on the ionic system considered) whereas the down-range properties of the potential play a (somewhat) greater role in influencing diffusion-controlled processes. A detailed examination is made of ionic strength effects over a broad range of ionic concentrations. In the regime of low ionic strength, the limiting slope and intercept of the curve describing the dependence of log k/sub D/ on I/sup 1/2//(1+I/sup 1/2/) may differ considerably from the usual Debye--Hueckel limiting relations, depending on the particular model chosen to describe local saturation effects
18. Relationship between pore structure and compressive strength
Properties of concrete are strongly dependent on its pore structure features, porosity being an important one among them. This study deals with developing an understanding of the pore structure-compressive strength relationship in concrete. Several concrete mixtures with different pore structures are proportioned and ...
19. Phenotypic selection varies with pollination intensity across populations of Sabatia angularis.
Science.gov (United States)
Emel, Sarah L; Franks, Steven J; Spigler, Rachel B
2017-07-01
Pollinators are considered primary selective agents acting on plant traits, and thus variation in the strength of the plant-pollinator interaction might drive variation in the opportunity for selection and selection intensity across plant populations. Here, we examine whether these critical evolutionary parameters covary with pollination intensity across wild populations of the biennial Sabatia angularis. We quantified pollination intensity in each of nine S. angularis populations as mean stigmatic pollen load per population. For female fitness and three components, fruit number, fruit set (proportion of flowers setting fruit) and number of seeds per fruit, we evaluated whether the opportunity for selection varied with pollination intensity. We used phenotypic selection analyses to test for interactions between pollination intensity and selection gradients for five floral traits, including flowering phenology. The opportunity for selection via fruit set and seeds per fruit declined significantly with increasing pollen receipt, as expected. We demonstrated significant directional selection on multiple traits across populations. We also found that selection intensity for all traits depended on pollination intensity. Consistent with general theory about the relationship between biotic interaction strength and the intensity of selection, our study suggests that variation in pollination intensity drives variation in selection across S. angularis populations. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.
20. Probe tests microweld strength
Science.gov (United States)
1965-01-01
Probe is developed to test strength of soldered, brazed or microwelded joints. It consists of a spring which may be adjusted to the desired test pressure by means of a threaded probe head, and an indicator lamp. Device may be used for electronic equipment testing.
1. Improvement of the fatigue strength of AISI 4140 steel by an ion nitriding process
Energy Technology Data Exchange (ETDEWEB)
Celik, A. [Atatuerk Univ., Erzurum (Turkey). Dept. of Mech. Eng.; Karadeniz, S. [Dokuz Eyluel Univ., Izmir (Turkey). Dept. of Mech. Eng.
1995-06-01
The influence of plasma nitriding on the fatigue behaviour of AISI 4140 low-alloy steel was investigated under varying process conditions of temperature (500-600 C), time (1-12 h), heat treatment before ion nitriding (quenched and tempered, normalized) and gas mixture (50% H{sub 2}-50% N{sub 2}). A rotating bending fatigue machine was used to determine the fatigue strength. It was found that the plasma nitriding improves the fatigue strength and increases the fatigue limit depending on the surface hardness of the case depth. The microstructure of surface and diffusion layers was examined by optical microscopy. The fracture surface of specimens and the origin of fatigue cracks were observed by scanning electron microscopy.
2. Time varying, multivariate volume data reduction
Energy Technology Data Exchange (ETDEWEB)
Ahrens, James P [Los Alamos National Laboratory; Fout, Nathaniel [UC DAVIS; Ma, Kwan - Liu [UC DAVIS
2010-01-01
Large-scale supercomputing is revolutionizing the way science is conducted. A growing challenge, however, is understanding the massive quantities of data produced by large-scale simulations. The data, typically time-varying, multivariate, and volumetric, can occupy from hundreds of gigabytes to several terabytes of storage space. Transferring and processing volume data of such sizes is prohibitively expensive and resource intensive. Although it may not be possible to entirely alleviate these problems, data compression should be considered as part of a viable solution, especially when the primary means of data analysis is volume rendering. In this paper we present our study of multivariate compression, which exploits correlations among related variables, for volume rendering. Two configurations for multidimensional compression based on vector quantization are examined. We emphasize quality reconstruction and interactive rendering, which leads us to a solution using graphics hardware to perform on-the-fly decompression during rendering. In this paper we present a solution which addresses the need for data reduction in large supercomputing environments where data resulting from simulations occupies tremendous amounts of storage. Our solution employs a lossy encoding scheme to acrueve data reduction with several options in terms of rate-distortion behavior. We focus on encoding of multiple variables together, with optional compression in space and time. The compressed volumes can be rendered directly with commodity graphics cards at interactive frame rates and rendering quality similar to that of static volume renderers. Compression results using a multivariate time-varying data set indicate that encoding multiple variables results in acceptable performance in the case of spatial and temporal encoding as compared to independent compression of variables. The relative performance of spatial vs. temporal compression is data dependent, although temporal compression has the
3. Strength functions for fragmented doorway states
International Nuclear Information System (INIS)
MacDonald, W.M.
1980-01-01
Coupling a strongly excited ''doorway state'' to weak ''hallway states'' distributes its strength into micro-resonances seen in differential cross sections taken with very good energy resolution. The distribution of strength is shown to be revealed by reduced widths of the K-matrix rather than by the imaginary part of poles of the S-matrix. Different strength functions (SF) constructed by averaging the K-matrix widths are then investigated to determine their dependences on energy and on parameters related to averages of microscopic matrix elements. A new sum rule on the integrated strength of these SF is derived and used to show that different averaging procedures actually distribute the strength differently. Finally, it is shown that the discontinuous summed strength defines spreading parameters for the doorway state only in strong coupling, where it approximates the idefinite integral of the continuous SF of MacDonald-Mekjian-Kerman-De Toledo Piza. A new method of ''parametric continuation'' is used to relate a discontinuous sliding box-average, or a finite sum, of discrete terms to a continous function
4. Determination of giant resonance strengths
International Nuclear Information System (INIS)
Serr, F.E.
1983-01-01
Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)
5. Impact strength on fiber-reinforced hybrid composite
International Nuclear Information System (INIS)
Firdaus, S M; Nurdina; Ariff, M Azmil
2013-01-01
Acrylonitrile-Butadiene-Styrene (ABS) has been well known composite in automotive players to have light weight with high impact strength material compared to sheet metal material which has high impact strength but heavy in weight. In this project, the impact strength properties of fabricated pure ABS were compared to the eight samples of hybrid ABS composite with different weight percentages of short fibers and particle sizes of ground rubber. The objective was to improve the impact strength in addition of short fibers and ground rubber particles. These samples were then characterized using an un-notched Izod impact test. Results show that the increasing of filler percentage yielded an adverse effect on the impact strength of the hybrid composite. The effect of the ground rubber particulate sizes however are deemed to be marginal than the effect of varying filler percentage based on the collected impact strength data from all physically tested hybrid composites
6. Evaluation of Pure Aluminium Inoculated with Varying Grain Sizes of an Agro-waste based Inoculant
Directory of Open Access Journals (Sweden)
2017-04-01
Full Text Available Pure Aluminium and its alloy are widely utilized in Engineering and Industrial applications due to certain significant properties such as softness, ductility, corrosion resistance, and high electrical conductivity which it possesses. Addition of an agro-waste based grain refiner to the melt can alter the characteristics positively or negatively. Therefore, the aim of this paper is to investigate the inoculating capability of an agro-waste based inoculant and the effect of adding varying sizes of its grains on some of the properties of pure aluminium after solidification. The beneficial outcome of this investigation would enhance the economic value of the selected agro-waste and also broaden the applications of aluminium in Engineering. The assessed properties include; microstructure, micro hardness, ductility, and tensile strength. The agro-waste used as the grain refiner is pulverised cocoa bean shells (CBS. Three sets of test samples were produced using dry sand moulding process, with each melt having a specified grain size of the inoculant added to it (150, 225 and 300microns respectively. Ladle inoculation method was adopted. The cast samples after solidification were machined to obtain various shapes/sizes for the different analysis. The microstructural examination showed that the mechanical properties are dependent on the matrix as the aluminium grains became more refined with increasing grain size of the inoculant. I.e. Due to increasing grain size of the inoculant, the micro hardness increased (56, 61, 72HB as the aluminium crystal size became finer. Meanwhile, the tensile strength (284, 251, 223N/mm2 and ductility (1.82, 0.91, 0.45%E decreased as grain size of the inoculant increased. The overall results showed that the used agro-waste based inoculant has the capability of refining the crystal size of pure aluminium as its grain size increases. This will make the resulting aluminium alloy applicable in areas where hardness is of
7. Impact strength of small icy bodies that experienced multiple collisions
Science.gov (United States)
Yasui, Minami; Hayama, Ryo; Arakawa, Masahiko
2014-05-01
Frequent collisions are common for small bodies in the Solar System, and the cumulative damage to these bodies is thought to significantly affect their evolution. It is important to study the effects of multiple impacts such as the number of impacts on the impact strength and the ejection velocity of impact fragments. Here we conducted multiple-impact experiments using a polycrystalline water ice target, varying the number of impacts from 1 to 10 times. An ice cylindrical projectile was impacted at 84-502 m s-1 by using a single-stage gas gun in a cold room between -10 and -15 °C. The impact strength of the ice target that experienced a single impact and multiple impacts is expressed by the total energy density applied to the same target, ΣQ, and this value was observed to be 77.6 J kg-1. The number of fine impact fragments at a fragment mass normalized by an initial target mass, m/Mt0 ∼ 10-6, nm, had a good correlation with the single energy density at each shot, Qj, and the relationship was shown to be nm=10·Qj1.31±0.12. We also estimated the cumulative damage of icy bodies as a total energy density accumulated by past impacts, according to the crater scaling laws proposed by Housen et al. (Housen, K.R., Schmidt, R.M., Holsapple, K.A. [1983]. J. Geophys. Res. 88, 2485-2499) of ice and the crater size distributions observed on Phoebe, a saturnian icy satellite. We found that the cumulative damage of Phoebe depended significantly on the impact speed of the impactor that formed the craters on Phoebe; and the cumulative damage was about one-third of the impact strength ΣQ* at 500 m s-1 whereas it was almost zero at 3.2 km s-1.
8. Statistical Analysis Of Failure Strength Of Material Using Weibull Distribution
International Nuclear Information System (INIS)
Entin Hartini; Mike Susmikanti; Antonius Sitompul
2008-01-01
In evaluation of ceramic and glass materials strength a statistical approach is necessary Strength of ceramic and glass depend on its measure and size distribution of flaws in these material. The distribution of strength for ductile material is narrow and close to a Gaussian distribution while strength of brittle materials as ceramic and glass following Weibull distribution. The Weibull distribution is an indicator of the failure of material strength resulting from a distribution of flaw size. In this paper, cumulative probability of material strength to failure probability, cumulative probability of failure versus fracture stress and cumulative probability of reliability of material were calculated. Statistical criteria calculation supporting strength analysis of Silicon Nitride material were done utilizing MATLAB. (author)
9. Redox Buffer Strength
Science.gov (United States)
de Levie, Robert
1999-04-01
The proper functioning of enzymes in bodily fluids requires that the pH be maintained within rather narrow limits. The first line of defense against large pH fluctuations in such fluids is the passive control provided by the presence of pH buffers. The ability of pH buffers to stabilize the pH is indicated by the buffer value b introduced in 1922 by van Slyke. It is equally important for many enzymes that the redox potential is kept within a narrow range. In that case, stability of the potential is most readily achieved with a redox buffer. In this communication we define the redox buffer strength by analogy with acid-base buffer strength.
10. Strength capability while kneeling.
Science.gov (United States)
Haslegrave, C M; Tracy, M F; Corlett, E N
1997-12-01
Work sometimes has to be carried out kneeling, particularly where jobs are performed in confined spaces as is common for miners, aircraft baggage handlers and maintenance workers. In order to assess the risks in performing forceful tasks under such conditions, data is needed on strength capabilities of kneeling subjects. A study was undertaken to measure isometric strength in single-handed exertions for male subjects and to investigate the effects on this of task layout factors (direction of force exertion, reach distance, height of the workpiece and orientation relative to the subject's sagittal plane). The data has been tabulated to show the degree to which strength may be reduced in different situations and analysis of the task factors showed their influence to be complex with direction of exertion and reach distance having the greatest effect. The results also suggest that exertions are weaker when subjects are kneeling on two knees than when kneeling on one knee, although this needs to be confirmed by direct experimental comparison.
11. Steady shear viscosity of stirred yoghurts with varying ropiness
NARCIS (Netherlands)
van Marle, M.E.; van Marle, M.E.; van den Ende, Henricus T.M.; de Kruif, C.G.; de Kruif, C.G.; Mellema, J.
1999-01-01
Stirred yogurt was viewed as a concentrated dispersion of aggregates consisting of protein particles. The steady-shear behavior of three types of stirred yogurt with varying ropiness was investigated experimentally. To describe the shear-dependent viscosity, a microrheological model was used which
12. A varying-α brane world cosmology
International Nuclear Information System (INIS)
Youm, Donam
2001-08-01
We study the brane world cosmology in the RS2 model where the electric charge varies with time in the manner described by the varying fine-structure constant theory of Bekenstein. We map such varying electric charge cosmology to the dual variable-speed-of-light cosmology by changing system of units. We comment on cosmological implications for such cosmological models. (author)
13. Modelling tourists arrival using time varying parameter
Science.gov (United States)
Suciptawati, P.; Sukarsa, K. G.; Kencana, Eka N.
2017-06-01
The importance of tourism and its related sectors to support economic development and poverty reduction in many countries increase researchers’ attentions to study and model tourists’ arrival. This work is aimed to demonstrate time varying parameter (TVP) technique to model the arrival of Korean’s tourists to Bali. The number of Korean tourists whom visiting Bali for period January 2010 to December 2015 were used to model the number of Korean’s tourists to Bali (KOR) as dependent variable. The predictors are the exchange rate of Won to IDR (WON), the inflation rate in Korea (INFKR), and the inflation rate in Indonesia (INFID). Observing tourists visit to Bali tend to fluctuate by their nationality, then the model was built by applying TVP and its parameters were approximated using Kalman Filter algorithm. The results showed all of predictor variables (WON, INFKR, INFID) significantly affect KOR. For in-sample and out-of-sample forecast with ARIMA’s forecasted values for the predictors, TVP model gave mean absolute percentage error (MAPE) as much as 11.24 percent and 12.86 percent, respectively.
14. Varying coefficients model with measurement error.
Science.gov (United States)
Li, Liang; Greene, Tom
2008-06-01
We propose a semiparametric partially varying coefficient model to study the relationship between serum creatinine concentration and the glomerular filtration rate (GFR) among kidney donors and patients with chronic kidney disease. A regression model is used to relate serum creatinine to GFR and demographic factors in which coefficient of GFR is expressed as a function of age to allow its effect to be age dependent. GFR measurements obtained from the clearance of a radioactively labeled isotope are assumed to be a surrogate for the true GFR, with the relationship between measured and true GFR expressed using an additive error model. We use locally corrected score equations to estimate parameters and coefficient functions, and propose an expected generalized cross-validation (EGCV) method to select the kernel bandwidth. The performance of the proposed methods, which avoid distributional assumptions on the true GFR and residuals, is investigated by simulation. Accounting for measurement error using the proposed model reduced apparent inconsistencies in the relationship between serum creatinine and GFR among different clinical data sets derived from kidney donor and chronic kidney disease source populations.
15. Scaling properties in time-varying networks with memory
Science.gov (United States)
Kim, Hyewon; Ha, Meesoon; Jeong, Hawoong
2015-12-01
The formation of network structure is mainly influenced by an individual node's activity and its memory, where activity can usually be interpreted as the individual inherent property and memory can be represented by the interaction strength between nodes. In our study, we define the activity through the appearance pattern in the time-aggregated network representation, and quantify the memory through the contact pattern of empirical temporal networks. To address the role of activity and memory in epidemics on time-varying networks, we propose temporal-pattern coarsening of activity-driven growing networks with memory. In particular, we focus on the relation between time-scale coarsening and spreading dynamics in the context of dynamic scaling and finite-size scaling. Finally, we discuss the universality issue of spreading dynamics on time-varying networks for various memory-causality tests.
16. Forecasting the compressive strength of soil-concretedepending on ...
African Journals Online (AJOL)
One of the most important physical and mechanical properties of soil-concrete is the compressive strength. To this end we carried out a study of soil-concrete strength depending on its curing conditions and percentage of cement. For our study we used loam soil with the plasticity index of Ip = 12.3, Portland cement of type I, ...
17. Assessment of maximal handgrip strength : How many attempts are needed?
NARCIS (Netherlands)
Reijnierse, Esmee M.; de Jong, Nynke; Trappenburg, Marijke C.; Blauw, Gerard Jan; Butler-Browne, Gillian; Gapeyeva, Helena; Hogrel, Jean Yves; Mcphee, Jamie S.; Narici, Marco V.; Sipilä, Sarianna; Stenroth, Lauri; van Lummel, Rob C.; Pijnappels, Mirjam; Meskers, Carel G M; Maier, Andrea B.
Background: Handgrip strength (HGS) is used to identify individuals with low muscle strength (dynapenia). The influence of the number of attempts on maximal HGS is not yet known and may differ depending on age and health status. This study aimed to assess how many attempts of HGS are required to
18. Harmonic strengths of PEP dipoles and some related effects and lessons
International Nuclear Information System (INIS)
Spencer, J.E.
1981-09-01
The harmonic content of magnets such as the standard PEP bend is (among other things) a function of excitation current, the way the current is set and even the magnetization history. For instance, harmonic strengths generally vary not only with the magnitude of the current but the direction and rate at which the current is approached and set. The field distribution resulting from different procedures can vary markedly depending on both the mechanical and magnetic design and the degree to which eddy current effects are emphasized. Variations among magnets of the same design result from variations in the iron as well as overall magnet fabrication procedures. Because the field distribution may also depend in the previous history of a magnet, all PEP dipoles were subjected to what are called ''magnetization'' and ''standardization'' cycles before measurement---the latter depending on the former and intended to set the initial conditions of the magnet to a reproducible standard. The primary goal of the magnetic measurements was then to determine the dipole strength as a function of current for each magnet based on a practical setting algorithm. The main constraints on the algorithm were reproducibility of the integrated field, speed, power and reduction of higher harmonics. Quadrupole and sextupole strengths were also measured on about one-half of the magnets at one current. This note presents the data and discusses it from the the viewpoint of subsequent measurements with stored beams. The most important conclusion is that inability to fully distribute laminations according to heat number and/or strike number results in ''magnetic personalities'' among the magnets which are quite difficult to deal with afterwards although one can distribute ''non-standard'' magnets to minimize orbit distributions. 26 refs., 8 figs., 3 tabs
19. Strengths only or strengths and relative weaknesses? A preliminary study.
Science.gov (United States)
Rust, Teri; Diessner, Rhett; Reade, Lindsay
2009-10-01
Does working on developing character strengths and relative character weaknesses cause lower life satisfaction than working on developing character strengths only? The present study provides a preliminary answer. After 76 college students completed the Values in Action Inventory of Strengths (C. Peterson & M. E. P. Seligman, 2004), the authors randomly assigned them to work on 2 character strengths or on 1 character strength and 1 relative weakness. Combined, these groups showed significant gains on the Satisfaction With Life Scale (E. Diener, R. A. Emmons, R. J. Larsen, & S. Griffin, 1985), compared with a 32-student no-treatment group. However, there was no significant difference in gain scores between the 2-strengths group and the 1-character-strength-and-1-relative-character-weakness group. The authors discuss how focusing on relative character weaknesses (along with strengths) does not diminish-and may assist in increasing-life satisfaction.
20. The theoretical tensile strength of fcc crystals predicted from shear strength calculations
International Nuclear Information System (INIS)
Cerny, M; Pokluda, J
2009-01-01
This work presents a simple way of estimating uniaxial tensile strength on the basis of theoretical shear strength calculations, taking into account its dependence on a superimposed normal stress. The presented procedure enables us to avoid complicated and time-consuming analyses of elastic stability of crystals under tensile loading. The atomistic simulations of coupled shear and tensile deformations in cubic crystals are performed using first principles computational code based on pseudo-potentials and the plane wave basis set. Six fcc crystals are subjected to shear deformations in convenient slip systems and a special relaxation procedure controls the stress tensor. The obtained dependence of the ideal shear strength on the normal tensile stress seems to be almost linearly decreasing for all investigated crystals. Taking these results into account, the uniaxial tensile strength values in three crystallographic directions were evaluated by assuming a collapse of the weakest shear system. Calculated strengths for and loading were found to be mostly lower than previously calculated stresses related to tensile instability but rather close to those obtained by means of the shear instability analysis. On the other hand, the strengths for loading almost match the stresses related to tensile instability.
1. Creep Strength of Discontinuous Fibre Composites
DEFF Research Database (Denmark)
Pedersen, Ole Bøcker
1974-01-01
relation between stress and strain rate. Expressions for the interface stress, the creep velocity profile adjacent to the fibres and the creep strength of the composite are derived. Previous results for the creep strength, sc = aVfs0 ( \\frac[( Î )\\dot] [( Î )\\dot] 0 )1/nr1 + 1/n c=Vf001n1+1n in which[( Î...... )\\dot] is the composite creep rate,V f is the fibre volume fraction,sgr 0,epsi 0 andn are the constants in the matrix creep law. The creep strength coefficient agr is found to be very weakly dependent onV f and practically independent ofn whenn is greater than about 6....
International Nuclear Information System (INIS)
Linse, D.
1975-01-01
3. A two-locus model of spatially varying stabilizing or directional selection on a quantitative trait.
Science.gov (United States)
Geroldinger, Ludwig; Bürger, Reinhard
2014-06-01
The consequences of spatially varying, stabilizing or directional selection on a quantitative trait in a subdivided population are studied. A deterministic two-locus two-deme model is employed to explore the effects of migration, the degree of divergent selection, and the genetic architecture, i.e., the recombination rate and ratio of locus effects, on the maintenance of genetic variation. The possible equilibrium configurations are determined as functions of the migration rate. They depend crucially on the strength of divergent selection and the genetic architecture. The maximum migration rates are investigated below which a stable fully polymorphic equilibrium or a stable single-locus polymorphism can exist. Under stabilizing selection, but with different optima in the demes, strong recombination may facilitate the maintenance of polymorphism. However usually, and in particular with directional selection in opposite direction, the critical migration rates are maximized by a concentrated genetic architecture, i.e., by a major locus and a tightly linked minor one. Thus, complementing previous work on the evolution of genetic architectures in subdivided populations subject to diversifying selection, it is shown that concentrated architectures may aid the maintenance of polymorphism. Conditions are obtained when this is the case. Finally, the dependence of the phenotypic variance, linkage disequilibrium, and various measures of local adaptation and differentiation on the parameters is elaborated. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
4. Strength Training: For Overall Fitness
Science.gov (United States)
Healthy Lifestyle Fitness Strength training is an important part of an overall fitness program. Here's what strength training can do for ... is a key component of overall health and fitness for everyone. Lean muscle mass naturally diminishes with ...
5. Fatigue strength degradation of metals in corrosive environments
OpenAIRE
Adasooriya, Mudiyan Nirosha Damayanthi; Hemmingsen, Tor; Pavlou, Dimitrios
2017-01-01
Structures exposed to aggressive environmental conditions are often subjected to time-dependent loss of coating and loss of material due to corrosion; this causes reduction in the cross-sectional properties of the members, increased surface roughness, surface irregularities and corrosion pits, and degradation of material strengths. These effects have been identified and simulated in different research studies. However, time and corrosive media dependent fatigue strength curves for materials h...
6. Strength Training Following Hematopoietic Stem Cell Transplantation
Science.gov (United States)
Hacker, Eileen Danaher; Larson, Janet; Kujath, Amber; Peace, David; Rondelli, Damiano; Gaston, Lisa
2010-01-01
Background Patients receiving high-dose chemotherapy and hematopoietic stem cell transplantation (HSCT) experience considerable reductions in physical activity and deterioration of their health status. Objective The purpose of this pilot study was to test the effects of strength training compared to usual activity on physical activity, muscle strength, fatigue, health status perceptions, and quality of life following HSCT. Interventions/Methods Nineteen subjects were randomized to the exercise or control group. Moderate intensity strength training began following discharge from the hospital. Dependent variables included physical activity, muscle strength, fatigue, health status perceptions and quality of life. Variables were measured prior to admission to the hospital for HSCT, day 8 following HSCT, and six weeks following discharge from the hospital. Results Significant time effects were noted for many variables with anticipated declines in physical activity, muscle strength, fatigue, and health status perceptions immediately after HSCT with subsequent improvements six weeks following hospital discharge. One group effect was noted with subjects in the exercise group reporting less fatigue than subjects in the control group. Although no significant interactions were detected, the trends suggest that the exercise group may be more physically active following the intervention compared to the usual activity group. Conclusions This study demonstrates the potential positive effects of strength training on physical activity, fatigue, and quality of life in people receiving high-dose chemotherapy and HSCT. Implications for Practice Preliminary evidence is provided for using strength training to enhance early recovery following HSCT. Elastic resistance bands are easy to use and relatively inexpensive. PMID:21116175
7. Short-term Periodization Models: Effects on Strength and Speed-strength Performance.
Science.gov (United States)
Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena
2015-10-01
avoided because it does not provide an adequate training stimulus for gains in muscle cross-sectional area and strength performance. High-volume circuit strength training performed over 2 years negatively affected the development of the power output and maximal strength of the upper extremities in professional rugby players. Indeed, meta-analyses and results with weightlifters, American Football players, and throwers confirm the necessity of the habitual use of ≥80% 1 RM: (1) to improve maximal strength during the off-season and in-season in American Football, (2) to reach peak performance in maximal strength and vertical jump power during tapering in track-and-field, and (3) to produce hypertrophy and strength improvements in advanced athletes. The integration and extent of hypertrophy strength training in in-season conditioning depend on the duration of the contest period, the frequency of the contests, and the proportion of the conditioning program. Based on the literature, 72 h between hypertrophy strength training and strength-power training should be provided to allow for adequate regeneration times and therefore maximal stimulus intensities in training. This conclusion is only valid if the muscle is not trained otherwise during this regeneration phase. Thus, rotating hypertrophy and strength-power sessions in a microcycle during the season is a viable option. Comparative studies in competitive athletes who integrated strength training during pre-season conditioning confirm a tendency for gains in explosive strength and statistically significant improvements in medicine ball throw through SPP but not through daily undulating periodization. These findings indicate that to maximize the speed-strength in the short term (peaking), elite athletes should perform strength-power training twice per week. It is possible to perform a single strength-power session with the method of maximum explosive strength actions moving high-weight loads (90% 1 repetition maximum [RM]) at
8. Effect of tack coat application on interlayer shear strength of asphalt pavement: A state-of-the-art review based on application in the United States
Directory of Open Access Journals (Sweden)
Weiguang Zhang
2017-09-01
Full Text Available The effect of tack coat application on pavement interlayer shear strength attracts strong interest during asphalt paving. Given its extensive use, tack coat is known to behave as a bond material to reduce pavement distresses such as slippage crack. The effectiveness of tack coat in increasing shear strength may be affected by multiple factors, such as tack coat material, test condition, pavement surface condition, and moisture. This article is a literature review focus on how the interlayer shear strength varied when relevant influential factors are changing. Review results indicate that the interlayer shear strength increased with the decreased test temperature, increased traffic load (within design limit, and increased test confinement pressure. Additionally, the milled pavement surface always has higher shear strength then the non-milled pavement surface. It is also found that laboratory-prepared specimens resulted in higher interlayer shear strength than field pavement cores. The effect of other factors on tack coat application may follow different trends depending on mix type and existing pavement condition. For instance, optimum tack coat rate that corresponds to peak shear strength is widely reported, while it is also found that tack coat does not greatly affect shear strength on dry, clean and milled pavement surface. Furthermore, shear strength reduced when mixture is designed with high percentage of air voids or coarse aggregate structure, such as porous asphalt and stone mastic asphalt (SMA mixtures. More findings and recommendations can be found in this paper. Keywords: Tack coat, Interlayer shear strength, Asphalt pavement, Temperature, Milling, Mixture type
9. Do galactic potential wells depend on their environment?
Science.gov (United States)
Mo, H. J.; Lahav, O.
1993-01-01
Using galaxies in complete samples as tracers of the galaxy density field and about 1000 galaxies with measured circular velocities as targets, we examine the cross-correlation functions between the targets and tracers as a function of galaxy circular velocities. The correlation strength does not vary with the circular velocities except for elliptical galaxies with the highest velocity dispersions, where the effect may well be due to morphological segregations in clusters of galaxies. This is contrasted with the strong dependence of the correlation functions of dark halos on their circular velocities in some models of galaxy formation.
10. Investigating Time-Varying Drivers of Grid Project Emissions Impacts
Energy Technology Data Exchange (ETDEWEB)
Barrett, Emily L.; Thayer, Brandon L.; Pal, Seemita; Studarus, Karen E.
2017-11-15
The emissions consequences of smart grid technologies depend heavily on their context and vary not only by geographical location, but by time of year. The same technology operated to meet the same objective may increase the emissions associated with energy generation for part of the year and decrease emissions during other times. The Grid Project Impact Quantification (GridPIQ) tool provides the ability to estimate these seasonal variations and garner insight into the time-varying drivers of grid project emissions impacts. This work leverages GridPIQ to examine the emissions implications across years and seasons of adding energy storage technology to reduce daily peak demand in California and New York.
11. Anelasticity and strength in zirconia ceramics
International Nuclear Information System (INIS)
Matsuzawa, M.; Horibe, S.; Sakai, J.
2005-01-01
Non-elastic strain behavior was investigated for several different zirconia ceramics and a possible mechanism for anelasticity was discussed. Anelastic strain was detected in zirconia ceramics irrespective of the crystallographic phase and its productivity depended on the particular kind of dopant additive. It was found that the anelastic properties could be significantly influenced by the level of oxygen vacancy in the matrix, and that the anelastic strain might be produced by a light shift of ionic species. In order to investigate the effect of anelasticity on mechanical properties on zirconia ceramics, the tensile strength was investigated for a wide range of strain rates. The obviously unique strain rate dependence was observed only in the materials having anelastic properties. It was assumed that anelasticity could be efficient at improving the tensile strength. (orig.)
12. Spall Strength Measurements in Transparent Epoxy Polymers
Science.gov (United States)
Pepper, Jonathan; Rahmat, Meysam; Petel, Oren
2017-06-01
Polymer nanocomposites are seeing more frequent use in transparent armour applications. The role of the microstructure on the performance of these materials under dynamic tensile loading conditions is of particular interest. In the present study, a series of plate impact experiments was conducted in order to evaluate the dynamic response of an epoxy (EPON 828) cured with two differed hardeners. The purpose was to compare the role of these hardeners on the dynamic performance of the resulting transparent epoxy. The material response was resolved with a multi-channel photonic Doppler velocimeter. This system was used to determine the shock Hugoniot and dynamic tensile (spall) strength of the materials. The experimental results are presented in reference to spall theory and are evaluated against results predicted by an analytical model of the impacts. While varying the hardener did not change the shock Hugoniot of the epoxy, it did have an effect on the measured spall strengths.
13. Yield strength of attached copper film
International Nuclear Information System (INIS)
Zhang Yan; Zhang Jian-Min
2011-01-01
Variation of stress in attached copper film with an applied strain is measured by X-ray diffraction combined with a four-point bending method. A lower slope of the initial elastic segment of the curve of X-ray measured stress versus applied strain results from incomplete elastic strain transferred from the substrate to the film due to insufficiently strong interface cohesion. So the slope of the initial elastic segment of the X-ray stress (or X-ray strain directly) of the film against the substrate applied strain may be used to measure the film-substrate cohesive strength. The yield strength of the attached copper film is much higher than that of the bulk material and varies linearly with the inverse of the film thickness. (condensed matter: structural, mechanical, and thermal properties)
14. Annotation of selection strengths in viral genomes
DEFF Research Database (Denmark)
McCauley, Stephen; de Groot, Saskia; Mailund, Thomas
2007-01-01
Motivation: Viral genomes tend to code in overlapping reading frames to maximize information content. This may result in atypical codon bias and particular evolutionary constraints. Due to the fast mutation rate of viruses, there is additional strong evidence for varying selection between intra......- and intergenomic regions. The presence of multiple coding regions complicates the concept of Ka/Ks ratio, and thus begs for an alternative approach when investigating selection strengths. Building on the paper by McCauley & Hein (2006), we develop a method for annotating a viral genome coding in overlapping...... may thus achieve an annotation both of coding regions as well as selection strengths, allowing us to investigate different selection patterns and hypotheses. Results: We illustrate our method by applying it to a multiple alignment of four HIV2 sequences, as well as four Hepatitis B sequences. We...
15. Strength training for a child with suspected developmental coordination disorder.
Science.gov (United States)
Menz, Stacy M; Hatten, Kristin; Grant-Beuttler, Marybeth
2013-01-01
Children with developmental coordination disorder (DCD) demonstrate difficulty with feedforward motor control and use varied compensatory strategies. To examine gross motor function changes following strength training in a child with motor control difficulties. A girl aged 6 years 11 months, with apraxia and hypotonia, and demonstrating motor delays consistent with DCD. Twenty-four strength training sessions were completed using a universal exercise unit. Postintervention scores significantly improved on the Bruininks-Oseretsky test of motor proficiency, second edition, and the Canadian occupational performance measure scores and raised the developmental coordination disorder questionnaire, revised 2007, scores above the range where DCD is suspected. Nonsignificant changes in strength were observed. Improved function and significant gains in manual coordination were observed following blocked practice of isolated, simple joint movements during strength training. Improved motor skills may be because of effective use of feedforward control and improved stabilization. Strength training does not rehearse skills using momentum, explaining nonsignificant changes in locomotor or locomotion areas.
16. Dependence of some electromagnetic properties of superconductors on coupling strength
International Nuclear Information System (INIS)
Marsiglio, F.; Carbotte, J.P.; Blezius, J.
1990-01-01
We have calculated select electromagnetic properties for many real superconductors based on tunneling-derived electron-phonon spectral densities. We use this data to fit coefficients in semiphenomenological forms derived through a series of approximations to the exact microscopic expressions. It is found that the derived forms represent well the strong-coupling corrections
17. Ionic Strength Dependent Kinetics of Nanocolloidal Gold Deposition
NARCIS (Netherlands)
Brouwer, E.A.M.; Kooij, Ernst S.; Wormeester, Herbert; Poelsema, Bene
2003-01-01
The deposition kinetics of the irreversible adsorption of citrate-stabilized, nanocolloidal gold particles on Si/SiO2 surfaces, derivatized with (aminopropyl)triethoxysilane, is investigated in situ using single wavelength reflectometry. A well-defined flow of colloids toward the surface is realized
18. textural dependence of shear strength and consolidation of colliery
African Journals Online (AJOL)
eobe
for their use were based on the properties of a wide range of .... Fig. 1 shows the grain size distribution curves of the mine wastes. Each ... wholly above the ground water level while sulphate .... consolidation curve assumes the usual shape.
19. Dependence of electric strength on the ambient temperature
International Nuclear Information System (INIS)
Čaja, Alexander; Nemec, Patrik; Malcho, Milan
2014-01-01
At present, the volume concentration of electronic components in their miniaturization to different types of microchips and increasing their performance raises the problem of cooling such elements due to the increasing density of heat flow of heat loss. Compliance with safe operating temperature of active semiconductor element is very closely related to the reliability and durability not only components, but also the entire device. Often it is also necessary to electrically isolate the unit from the side of the cooler air. Cooling demand by natural convection is typical for applications with high operating reliability. To the reliability of the system for removing heat loss increased, it is necessary to minimize need to use the mechanically or electrically powered elements, such as circulation pumps or fans. Experience to date with applications of heat pipe in specific systems appears to be the most appropriate method of cooling
20. Gaussian discriminating strength
Science.gov (United States)
Rigovacca, L.; Farace, A.; De Pasquale, A.; Giovannetti, V.
2015-10-01
We present a quantifier of nonclassical correlations for bipartite, multimode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in Farace et al., [New J. Phys. 16, 073010 (2014), 10.1088/1367-2630/16/7/073010]. As the latter the new measure exploits the quantum Chernoff bound to gauge the susceptibility of the composite system with respect to local perturbations induced by unitary gates extracted from a suitable set of allowed transformations (the latter being identified by posing some general requirements). Closed expressions are provided for the case of two-mode Gaussian states obtained by squeezing or by linearly mixing via a beam splitter a factorized two-mode thermal state. For these density matrices, we study how nonclassical correlations are related with the entanglement present in the system and with its total photon number.
1. Spacetime-varying couplings and Lorentz violation
International Nuclear Information System (INIS)
Kostelecky, V. Alan; Lehnert, Ralf; Perry, Malcolm J.
2003-01-01
Spacetime-varying coupling constants can be associated with violations of local Lorentz invariance and CPT symmetry. An analytical supergravity cosmology with a time-varying fine-structure constant provides an explicit example. Estimates are made for some experimental constraints
2. Detection of dynamically varying interaural time differences
DEFF Research Database (Denmark)
Kohlrausch, Armin; Le Goff, Nicolas; Breebaart, Jeroen
2010-01-01
of fringes surrounding the probe is equal to the addition of the effects of the individual fringes. In this contribution, we present behavioral data for the same experimental condition, called dynamically varying ITD detection, but for a wider range of probe and fringe durations. Probe durations varied...
3. COMPARATIVE STUDY OF THE EFFECTS OF DETONATION NANODIAMONDS WITH VARIED PROPERTIES ON FUNCTIONAL STATE OF BRAIN NERVE TERMINALS
Directory of Open Access Journals (Sweden)
M. A. Galkin
2016-12-01
Full Text Available The aim of the study was to compare the effects of detonation nanodiamond preparations from different batches cleaned from impurities by diverse methods of chemical treatment on the membrane potential and glutamate transport characteristics of rat brain nerve terminals. The size of nanodiamond particles vary from 10–20 nm to 10 μm. There are carbonyl, hydroxyl and carboxyl functional groups on the surface of the particles. Physical-chemical properties such as a magnetic susceptibility and the amount of incombustible residue in samples of detonation nanodia-mond vary depending on the synthesis regime and the method of chemical cleaning of the product and therefore, the neuroactive properties of nanodiamonds from different batches can be different. It was shown by dynamic light scattering analysis that nanodiamond preparations from different batches treated by diverse technologies of chemical treatment had varied average size of particles and distribution of particles by size. Nanodiamond preparations from different batches changed the plasma membrane potential and caused membrane depolarization of nerve terminals. Analysis of the effects of nanodiamonds on transporter-mediated L-[14C]glutamate uptake by nerve terminals also revealed that all studied nanodiamond preparations decreased abovementioned parameter. Therefore, detonation nanodiamonds from different batches have similar principal effects on functional state of nerve terminals, however variability in their physical and chemical properties is associated with diverse strength of these effects.
4. Sink strength simulations using the Monte Carlo method: Applied to spherical traps
Science.gov (United States)
Ahlgren, T.; Bukonte, L.
2017-12-01
The sink strength is an important parameter for the mean-field rate equations to simulate temporal changes in the micro-structure of materials. However, there are noteworthy discrepancies between sink strengths obtained by the Monte Carlo and analytical methods. In this study, we show the reasons for these differences. We present the equations to estimate the statistical error for sink strength calculations and show the way to determine the sink strengths for multiple traps. We develop a novel, very fast Monte Carlo method to obtain sink strengths. The results show that, in addition to the well-known sink strength dependence of the trap concentration, trap radius and the total sink strength, the sink strength also depends on the defect diffusion jump length and the total trap volume fraction. Taking these factors into account, allows us to obtain a very accurate analytic expression for the sink strength of spherical traps.
5. Stimulus size dependence of hue changes induced by chromatic surrounds.
Science.gov (United States)
Kellner, Christian Johannes; Wachtler, Thomas
2016-03-01
A chromatic surround induces a change in the perceived hue of a stimulus. This shift in hue depends on the chromatic difference between the stimulus and the surround. We investigated how chromatic induction varies with stimulus size and whether the size dependence depends on the surround hue. Subjects performed asymmetric matching of color stimuli with different sizes in surrounds of different chromaticities. Generally, induced hue shifts decreased with increasing stimulus size. This decrease was quantitatively different for different surround hues. However, when size effects were normalized to an overall induction strength, the chromatic specificity was largely reduced. The separability of inducer chromaticity and stimulus size suggests that these effects are mediated by different neural mechanisms.
6. Newtonian cosmology with a time-varying constant of gravitation
International Nuclear Information System (INIS)
McVittie, G.C.
1978-01-01
Newtonian cosmology is based on the Eulerian equations of fluid mechanics combined with Poisson's equation modified by the introduction of a time-varying G. Spherically symmetric model universes are worked out with instantaneously uniform densities. They are indeterminate unless instantaneous uniformity of the pressure is imposed. When G varies as an inverse power of the time, the models can in some cases be shown to depend on the solution of a second-order differential equation which also occurs in the Friedmann models of general relativity. In Section 3, a method for 'passing through' a singularity of this equation is proposed which entails making four arbitrary mathematical assumptions. When G varies as (time) -1 , models with initially cycloidal motion are possible, each cycle becoming longer as time progresses. Finally, gravitation becomes so weak that the model expands to infinity. Kinetic and potential energies for the whole model are derived from the basic equations; their sum is not constant. (author)
7. Microcracking and durability of high strength concretes
International Nuclear Information System (INIS)
Yssorche, M.P.
1995-07-01
Durability of 28 days compressive strength concrete of 20 to 120 MPa has been studied. The ability of concrete to transport aggressive agents has been determined for four properties: the air permeability, the chloride diffusivity, the water absorption and the carbonation. A chloride migration test for high and very high strength concrete (HSC and VHSC) has been built. The relationship between transport properties and the compressive strength after one and 28 days of humid curing has always the same shape: transport decreases when strength increases. However, transport properties often vary in the ordinary concrete field. Beyond, the domain is much more limited. The relationship between transport properties and strength valid for ordinary concrete can not be simply extrapolated for HSC and VHSC. To determine the part of microcracking of HSC and VHSC, concrete behaviour stored in two mediums has been studied: the ones shaming the storing condition of concrete in auto-desiccation, the others reproducing the storing conditions of concrete in desiccation. Auto-desiccation (measuring relative humidity at balance) and desiccation (measuring mass losses) have been showed. Microcracks and shrinkage strains have been measured. It has been showed that auto-desiccation microcracks proving in HSC or VHSC don't question the durability. Microcracks, as for permeability, do not develop between 28 days and one year. On the contrary, desiccation microcracks observed in HSC and VHSC, increase with transport properties between 28 days and 1.5 year. Thus, a bulk concrete is always more durable than a cover concrete. At last, the good influence of increase of curing of 1 to 28 days on the transport of all concretes has been emphasized. (author)
8. Yield and strength properties of the Ti-6-22-22S alloy over a wide strain rate and temperature range
International Nuclear Information System (INIS)
Krueger, L.; Kanel, G.I.; Razorenov, S.V.; Bezrouchko, G.S.; Meyer, L.
2002-01-01
A mechanical behavior of the Ti-6-22-22S alloy was studied under uniaxial strain conditions at shock-wave loading and under uniaxial compressive stress conditions over a strain rate range of 10-4 s-1 to 103 s-1. The test temperature was varied from -175 deg. C to 620 deg. C. The strain-rate and the temperature dependencies of the yield stress obtained from the uniaxial stress tests and from the shock-wave experiments are in a good agreement and demonstrate a significant decrease in the yield strength as the temperature increases. This indicates the thermal activation mechanism of plastic deformation of the alloy is maintained at strain rates up to 106 s-1. Variation of sample thickness from 2.24 to 10 mm results in relatively small variations in the dynamic yield strength and the spall strength over the whole temperature range
9. Compressive and flexural strength of high strength phase change mortar
Science.gov (United States)
Qiao, Qingyao; Fang, Changle
2018-04-01
High-strength cement produces a lot of hydration heat when hydrated, it will usually lead to thermal cracks. Phase change materials (PCM) are very potential thermal storage materials. Utilize PCM can help reduce the hydration heat. Research shows that apply suitable amount of PCM has a significant effect on improving the compressive strength of cement mortar, and can also improve the flexural strength to some extent.
10. Making High-Tensile-Strength Amalgam Components
Science.gov (United States)
Grugel, Richard
2008-01-01
Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams
11. Modeling information diffusion in time-varying community networks
Science.gov (United States)
Cui, Xuelian; Zhao, Narisa
2017-12-01
Social networks are rarely static, and they typically have time-varying network topologies. A great number of studies have modeled temporal networks and explored social contagion processes within these models; however, few of these studies have considered community structure variations. In this paper, we present a study of how the time-varying property of a modular structure influences the information dissemination. First, we propose a continuous-time Markov model of information diffusion where two parameters, mobility rate and community attractiveness, are introduced to address the time-varying nature of the community structure. The basic reproduction number is derived, and the accuracy of this model is evaluated by comparing the simulation and theoretical results. Furthermore, numerical results illustrate that generally both the mobility rate and community attractiveness significantly promote the information diffusion process, especially in the initial outbreak stage. Moreover, the strength of this promotion effect is much stronger when the modularity is higher. Counterintuitively, it is found that when all communities have the same attractiveness, social mobility no longer accelerates the diffusion process. In addition, we show that the local spreading in the advantage group has been greatly enhanced due to the agglomeration effect caused by the social mobility and community attractiveness difference, which thus increases the global spreading.
12. Time Varying Market Integration and Expected Rteurns in Emerging Markets
OpenAIRE
Jong, F.C.J.M. de; Roon, F.A. de
2001-01-01
We use a simple model in which the expected returns in emerging markets depend on their systematic risk as measured by their beta relative to the world portfolio as well as on the level of integration in that market.The level of integration is a time-varying variable that depends on the market value of the assets that can be held by domestic investors only versus the market value of the assets that can be traded freely.Our empirical analysis for 30 emerging markets shows that there are strong...
13. Institutional Strength in Depth
International Nuclear Information System (INIS)
Weightman, M.
2016-01-01
Much work has been undertaken in order to identify, learn and implement the lessons from the TEPCO Fukushima Daiichi nuclear accident. These have mainly targeted on engineering or operational lessons. Less attention has been paid to the institutional lessons, although there have been some measures to improve individual peer reviews, particularly by the World Association of Nuclear Operators, and the authoritative IAEA report published in 2015 brought forward several important lessons for regulators and advocated a system approach. The report noted that one of the contributing factors the accident was the tendency of stakeholders not to challenge. Additionally, it reported deficiencies in the regulatory authority and system. Earlier, the root cause of the accident was identified by a Japanese independent parliamentary report as being cultural and institutional. The sum total of the institutions, the safety system, was ineffective. While it is important to address the many technical and operational lessons these may not necessary address this more fundamental lesson, and may not serve to provide robust defences against human or institutional failings over a wide variety of possible events and combinations. The overall lesson is that we can have rigorous and comprehensive safety standards and other tools in place to deliver high levels of safety, but ultimately what is important is the ability of the nuclear safety system to ensure that the relevant institutions diligently and effectively apply those standards and tools — to be robust and resilient. This has led to the consideration of applying the principles of the strength in depth philosophy to a nuclear safety system as a way of providing a framework for developing, assessing, reviewing and improving the system. At an IAEA conference in October 2013, a model was presented for a robust national nuclear safety system based on strength in depth philosophy. The model highlighted three main layers: industry, the
14. Competing Grain Boundary and Interior Deformation Mechanisms with Varying Sizes
Energy Technology Data Exchange (ETDEWEB)
Zhang, Wei [University of Tennessee (UT); Gao, Yanfei [ORNL; Nieh, T. G. [University of Tennessee, Knoxville (UTK)
2018-01-01
In typical coarse-grained alloys, the dominant plastic deformations are dislocation gliding or climbing, and material strengths can be tuned by dislocation interactions with grain boundaries, precipitates, solid solutions, and other defects. With the reduction of grain size, the increase of material strengths follows the classic Hall-Petch relationship up to nano-grained materials. Even at room temperatures, nano-grained materials exhibit strength softening, or called the inverse Hall-Petch effect, as grain boundary processes take over as the dominant deformation mechanisms. On the other hand, at elevated temperatures, grain boundary processes compete with grain interior deformation mechanisms over a wide range of the applied stress and grain sizes. This book chapter reviews and compares the rate equation model and the microstructure-based finite element simulations. The latter explicitly accounts for the grain boundary sliding, grain boundary diffusion and migration, as well as the grain interior dislocation creep. Therefore the explicit finite element method has clear advantages in problems where microstructural heterogeneities play a critical role, such as in the gradient microstructure in shot peening or weldment. Furthermore, combined with the Hall-Petch effect and its breakdown, the above competing processes help construct deformation mechanism maps by extending from the classic Frost-Ashby type to the ones with the dependence of grain size.
15. Perturbation theory for arbitrary coupling strength?
Science.gov (United States)
2018-03-01
We present a new formulation of perturbation theory for quantum systems, designated here as: “mean field perturbation theory” (MFPT), which is free from power-series-expansion in any physical parameter, including the coupling strength. Its application is thereby extended to deal with interactions of arbitrary strength and to compute system-properties having non-analytic dependence on the coupling, thus overcoming the primary limitations of the “standard formulation of perturbation theory” (SFPT). MFPT is defined by developing perturbation about a chosen input Hamiltonian, which is exactly solvable but which acquires the nonlinearity and the analytic structure (in the coupling strength) of the original interaction through a self-consistent, feedback mechanism. We demonstrate Borel-summability of MFPT for the case of the quartic- and sextic-anharmonic oscillators and the quartic double-well oscillator (QDWO) by obtaining uniformly accurate results for the ground state of the above systems for arbitrary physical values of the coupling strength. The results obtained for the QDWO may be of particular significance since “renormalon”-free, unambiguous results are achieved for its spectrum in contrast to the well-known failure of SFPT in this case.
16. Prediction of shear and tensile strength of the diffusion bonded AA5083 and AA7075 aluminium alloy using ANN
International Nuclear Information System (INIS)
Sagai Francis Britto, A.; Raj, R. Edwin; Mabel, M. Carolin
2017-01-01
Diffusion bonding is a pressure welding technique to establish bonds by inter diffusion of atoms. Bonding characteristics were generated by varying the significant process conditions such as the bonding temperature, the pressing load and the duration of pressure while bonding the aluminium alloys AA5083 and AA7075. Deriving analytical correlation with the process variables to weld strength is quite involved due to the non-linear dependency of the process variables with the mechanical strength of the joints. An arbitrary function approximation mechanism, the artificial neural network (ANN) is therefore employed to develop the models for predicting the mechanical properties of the bonded joints. Back propagation technique, which alters the network weights to minimize the mean square error was used to develop the ANN models. The models were tested, validated and found to be satisfactory with good prediction accuracy.
17. Prediction of shear and tensile strength of the diffusion bonded AA5083 and AA7075 aluminium alloy using ANN
Energy Technology Data Exchange (ETDEWEB)
Sagai Francis Britto, A. [Department of Mechanical Engineering, St.Xavier' s Catholic College of Engineering, Nagercoil 629003,Tamil Nadu (India); Raj, R. Edwin, E-mail: [email protected] [Department of Mechanical Engineering, St.Xavier' s Catholic College of Engineering, Nagercoil 629003,Tamil Nadu (India); Mabel, M. Carolin [Department of Electrical and Electronics Engineering, St.Xavier' s Catholic College of Engineering, Nagercoil 629003,Tamil Nadu (India)
2017-04-24
Diffusion bonding is a pressure welding technique to establish bonds by inter diffusion of atoms. Bonding characteristics were generated by varying the significant process conditions such as the bonding temperature, the pressing load and the duration of pressure while bonding the aluminium alloys AA5083 and AA7075. Deriving analytical correlation with the process variables to weld strength is quite involved due to the non-linear dependency of the process variables with the mechanical strength of the joints. An arbitrary function approximation mechanism, the artificial neural network (ANN) is therefore employed to develop the models for predicting the mechanical properties of the bonded joints. Back propagation technique, which alters the network weights to minimize the mean square error was used to develop the ANN models. The models were tested, validated and found to be satisfactory with good prediction accuracy.
18. Eesti film võistleb Karlovy Varys
Index Scriptorium Estoniae
2008-01-01
8. juulil esilinastub Karlovy Vary filmifestivalil Rene Vilbre noortefilm "Mina olin siin", mille aluseks on Sass Henno romaan "Mina olin siin. Esimene arest", stsenaariumi kirjutas Ilmar Raag. Film võistleb võistlusprogrammis "East of the West"
19. Matching Value Propositions with Varied Customer Needs
DEFF Research Database (Denmark)
Heikka, Eija-Liisa; Frandsen, Thomas; Hsuan, Juliana
2018-01-01
Organizations seek to manage varied customer segments using varied value propositions. The ability of a knowledge-intensive business service (KIBS) provider to formulate value propositions into attractive offerings to varied customers becomes a competitive advantage. In this specific business based...... on often highly abstract service offerings, this requires the provider to have a clear overview of its knowledge and resources and how these can be configured to obtain the desired customization of services. Hence, the purpose of this paper is to investigate how a KIBS provider can match value propositions...... with varied customer needs utilizing service modularity. To accomplish this purpose, a qualitative multiple case study is organized around 5 projects allowing within-case and cross-case comparisons. Our findings describe how through the configuration of knowledge and resources a sustainable competitive...
20. Compilation of Instantaneous Source Functions for Varying ...
African Journals Online (AJOL)
Compilation of Instantaneous Source Functions for Varying Architecture of a Layered Reservoir with Mixed Boundaries and Horizontal Well Completion Part III: B-Shaped Architecture with Vertical Well in the Upper Layer.
1. Compilation of Instantaneous Source Functions for Varying ...
African Journals Online (AJOL)
Compilation of Instantaneous Source Functions for Varying Architecture of a Layered Reservoir with Mixed Boundaries and Horizontal Well Completion Part IV: Normal and Inverted Letter 'h' and 'H' Architecture.
2. Crack formation and fracture energy of normal and high strength ...
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Abstract. The crack path through composite materials such as concrete depends on the mechanical interaction of inclusions with the cement-based matrix. Fracture energy depends on the deviations of a real crack from an idealized crack plane. Fracture energy and strain softening of normal, high strength, and self- ...
3. Strength evaluation of prosthetic check sockets, copolymer sockets, and definitive laminated sockets.
Science.gov (United States)
Gerschutz, Maria J; Haynes, Michael L; Nixon, Derek; Colvin, James M
2012-01-01
A prosthesis encounters loading through forces and torques exerted by the person with amputation. International Organization for Standardization (ISO) standard 10328 was designed to test most lower-limb prosthetic components. However, this standard does not include prosthetic sockets. We measured static failure loads of prosthetic sockets using a modified ISO 10328 and then compared them with the criteria set by this standard for other components. Check socket (CS) strengths were influenced by thickness, material choice, and fabrication method. Copolymer socket (CP) strengths depended on thickness and fabrication methods. A majority of the CSs and all of the CPs failed to pass the ISO 10328 ductile loading criterion. In contrast, the strengths of definitive laminated sockets (DLs) were influenced more by construction material and technique. A majority of the DLs failed to pass the ISO 10328 brittle loading criterion. Analyzing prosthetic sockets from a variety of facilities demonstrated that socket performance varies considerably between and within facilities. The results from this article provide a foundation for understanding the quality of prosthetic sockets, some insight into possible routes for improving the current care delivered to patients, and a comparative basis for future technology.
4. Investigation on interlaminar shear strength properties of disc laser machined consolidated CF-PPS laminates
Directory of Open Access Journals (Sweden)
2011-03-01
Full Text Available In consequence of an increased interest in using endless carbon fibre reinforced thermoplastic composites (TPC, automated and highly productive processing technologies for cutting and trimming steps of consolidated materials are sought. In this paper, the influence on the thermal effect caused by laser cutting with respect to static strength properties of TPC based on a polyphenylene sulfide (PPS matrix is studied. For the cutting experiments, consolidated TPC laminates at varying thicknesses up to s = 3.1 mm and a disc laser emitting at a wavelength of λ = 1030 nm at a maximum output power of PL = 2 kW are used. For the first time, the resulting magnitude of the heat affected zone (HAZ at the cutting edge of the composite material is correlated with interlaminar shear strength tests. The results are compared to specimens prepared by milling and abrasive water jet cutting. Depending on the laminate thickness, the laser treated TPC samples show comparable properties to those of conventionally processed specimens. A reduced load bearing area, as a consequence of damaged fibre-matrix-adhesion due to laser impact, is identified as main factor for the reduction of interlaminar shear strengths for higher laminate thicknesses.
5. Carbonate adsorption onto goethite as a function of pH and ionic strength
International Nuclear Information System (INIS)
Rundberg, R.S.; Albinsson, Y.
1991-01-01
The adsorption of carbonate onto geothite was studied as a function of both pH and ionic strength (NaClO 4 electrolyte) using 14 C tracer. The pH ranged from 2.5 to 11.6. The ionic strength was controlled by varying the NaClO 4 concentration and ranged from 0.01 to 0.1 molar. The results indicate that carbonate is adsorbed on goethite as primarily an inner-sphere complex at pH values above the point of zero charge. This is inferred from the lack of dependence on ionic strength in the adsorption of carbonate. Below the point of zero charge carbonate is adsorbed by an additional outer-sphere mechanism. An adsorption isotherm was measured at pH 7.0 with an electrolyte concentration of 0.01M. Deconvolution of the isotherm proved that at least two sorption mechanisms exist. These mechanisms lead to large distribution coefficients at low pH. Thereby making the complete removal and exclusion of carbonate from an aqueous goethite system difficult, for the purpose of characterizing a ''clean'' goethite surface
6. Abstract Spatial Reasoning as an Autistic Strength
Science.gov (United States)
Stevenson, Jennifer L.; Gernsbacher, Morton Ann
2013-01-01
Autistic individuals typically excel on spatial tests that measure abstract reasoning, such as the Block Design subtest on intelligence test batteries and the Raven’s Progressive Matrices nonverbal test of intelligence. Such well-replicated findings suggest that abstract spatial processing is a relative and perhaps absolute strength of autistic individuals. However, previous studies have not systematically varied reasoning level – concrete vs. abstract – and test domain – spatial vs. numerical vs. verbal, which the current study did. Autistic participants (N = 72) and non-autistic participants (N = 72) completed a battery of 12 tests that varied by reasoning level (concrete vs. abstract) and domain (spatial vs. numerical vs. verbal). Autistic participants outperformed non-autistic participants on abstract spatial tests. Non-autistic participants did not outperform autistic participants on any of the three domains (spatial, numerical, and verbal) or at either of the two reasoning levels (concrete and abstract), suggesting similarity in abilities between autistic and non-autistic individuals, with abstract spatial reasoning as an autistic strength. PMID:23533615
7. Cyanogen strengths of globular cluster post-main-sequence stars
International Nuclear Information System (INIS)
Hesser, J.E.; Hartwick, F.D.A.; McClure, R.D.
1976-01-01
CN strengths in the peculiar clusters ω Cen and M22 and the metal-rich clusters 47 Tuc, M71, and NGC 6352 are found to vary markedly from star to star. The strong variations in CN strength found earlier for ω Cen by Norris and Bessell and by Dickens and Bell are shown to extend to fainter stars, although expected correlations of CN strength with position in the color-magnitude (C-M) diagram are less evident in our sample. Several CN and metal-strong stars were also observed in M22. We conclude that CN, once it appears in globular clusters, can vary much more than it does in equivalent Population I samples, a result we briefly examine in light of current understanding regarding physical processes in the stars themselves and of models of galactic chemical evolution
8. Experimental examination of intraspecific density-dependent competition during the breeding period in monarch butterflies (Danaus plexippus.
Directory of Open Access Journals (Sweden)
D T Tyler Flockhart
Full Text Available A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to measure the strength of density-dependent intraspecific competition on egg laying rate and larval survival and then applied our results to density estimates of wild monarch populations to model the strength of density dependence during the breeding season. Egg laying rates did not change with density but larvae at high densities were smaller, had lower survival, and weighed less as adults compared to lower densities. Using mean larval densities from field surveys resulted in conservative estimates of density-dependent population reduction that varied between breeding regions and different phases of the breeding season. Our results suggest the highest levels of population reduction due to density-dependent intraspecific competition occur early in the breeding season in the southern portion of the breeding range. However, we also found that the strength of density dependence could be almost five times higher depending on how many life-stages were used as part of field estimates. Our study is the first to link experimental results of a density-dependent reduction in vital rates to observed monarch densities in the wild and show that the effects of density dependent competition in monarchs varies across space and time, providing valuable information for developing robust, year-round population models in this migratory organism.
9. Vesicle biomechanics in a time-varying magnetic field.
Science.gov (United States)
Ye, Hui; Curcuru, Austen
2015-01-01
Cells exhibit distortion when exposed to a strong electric field, suggesting that the field imposes control over cellular biomechanics. Closed pure lipid bilayer membranes (vesicles) have been widely used for the experimental and theoretical studies of cellular biomechanics under this electrodeformation. An alternative method used to generate an electric field is by electromagnetic induction with a time-varying magnetic field. References reporting the magnetic control of cellular mechanics have recently emerged. However, theoretical analysis of the cellular mechanics under a time-varying magnetic field is inadequate. We developed an analytical theory to investigate the biomechanics of a modeled vesicle under a time-varying magnetic field. Following previous publications and to simplify the calculation, this model treated the inner and suspending media as lossy dielectrics, the membrane thickness set at zero, and the electric resistance of the membrane assumed to be negligible. This work provided the first analytical solutions for the surface charges, electric field, radial pressure, overall translational forces, and rotational torques introduced on a vesicle by the time-varying magnetic field. Frequency responses of these measures were analyzed, particularly the frequency used clinically by transcranial magnetic stimulation (TMS). The induced surface charges interacted with the electric field to produce a biomechanical impact upon the vesicle. The distribution of the induced surface charges depended on the orientation of the coil and field frequency. The densities of these charges were trivial at low frequency ranges, but significant at high frequency ranges. The direction of the radial force on the vesicle was dependent on the conductivity ratio between the vesicle and the medium. At relatively low frequencies (biomechanics under a time-varying magnetic field. Biological effects of clinical TMS are not likely to occur via alteration of the biomechanics of brain
10. Age-varying associations between nonmarital sexual behavior and depressive symptoms across adolescence and young adulthood.
Science.gov (United States)
Vasilenko, Sara A
2017-02-01
11. Novel boride base cermets with very high strength
International Nuclear Information System (INIS)
Ken-ichi Takagi; Mari Yonetsu; Yuji Yamasaki
2001-01-01
Mo 2 NiB 2 boride base cermets consist of a Mo 2 NiB 2 type complex boride as a hard phase and a Ni base binder. The addition of Cr and V to the cermets changed the boride structure from orthorhombic to tetragonal and resulted in the improvement of mechanical properties and microstructural refinement. The tetragonal Mo 2 NiB 2 was formed through the orthorhombic Mo 2 NiB 2 by the solid state reaction during sintering and not formed directly from the raw material powders. Ni-4.5B-46.9Mo-12.5V-xMn (wt.%) model cermets with five levels of Mn content from 0 to 10 wt.% were prepared to investigate the effects of Mn on the mechanical properties and microstructure Of Mo 2 NiB 2 base cermets. The transverse rupture strength (TRS) of the cermets depended strongly on the microstructure, which varied significantly with Mn content. The maximum TRS obtained at 2.5 wt.%Mn were 3.5 Gpa with hardness of 87 R A . (author)
DEFF Research Database (Denmark)
Sørensen, Herman
1995-01-01
Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength.......Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength....
13. Oscillator strengths for neutral technetium
International Nuclear Information System (INIS)
Garstang, R.H.
1981-01-01
Oscillator strengths have been calculated for most of the spectral lines of TcI which are of interest in the study of stars of spectral type S. Oscillator strengths have been computed for the corresponding transitions in MnI as a partial check of the technetium calculations
14. Relative scale and the strength and deformability of rock masses
Science.gov (United States)
Schultz, Richard A.
1996-09-01
The strength and deformation of rocks depend strongly on the degree of fracturing, which can be assessed in the field and related systematically to these properties. Appropriate Mohr envelopes obtained from the Rock Mass Rating (RMR) classification system and the Hoek-Brown criterion for outcrops and other large-scale exposures of fractured rocks show that rock-mass cohesive strength, tensile strength, and unconfined compressive strength can be reduced by as much as a factor often relative to values for the unfractured material. The rock-mass deformation modulus is also reduced relative to Young's modulus. A "cook-book" example illustrates the use of RMR in field applications. The smaller values of rock-mass strength and deformability imply that there is a particular scale of observation whose identification is critical to applying laboratory measurements and associated failure criteria to geologic structures.
15. Energy flux determines magnetic field strength of planets and stars.
Science.gov (United States)
Christensen, Ulrich R; Holzwarth, Volkmar; Reiners, Ansgar
2009-01-08
The magnetic fields of Earth and Jupiter, along with those of rapidly rotating, low-mass stars, are generated by convection-driven dynamos that may operate similarly (the slowly rotating Sun generates its field through a different dynamo mechanism). The field strengths of planets and stars vary over three orders of magnitude, but the critical factor causing that variation has hitherto been unclear. Here we report an extension of a scaling law derived from geodynamo models to rapidly rotating stars that have strong density stratification. The unifying principle in the scaling law is that the energy flux available for generating the magnetic field sets the field strength. Our scaling law fits the observed field strengths of Earth, Jupiter, young contracting stars and rapidly rotating low-mass stars, despite vast differences in the physical conditions of the objects. We predict that the field strengths of rapidly rotating brown dwarfs and massive extrasolar planets are high enough to make them observable.
16. On generalized scaling laws with continuously varying exponents
International Nuclear Information System (INIS)
Sittler, Lionel; Hinrichsen, Haye
2002-01-01
Many physical systems share the property of scale invariance. Most of them show ordinary power-law scaling, where quantities can be expressed as a leading power law times a scaling function which depends on scaling-invariant ratios of the parameters. However, some systems do not obey power-law scaling, instead there is numerical evidence for a logarithmic scaling form, in which the scaling function depends on ratios of the logarithms of the parameters. Based on previous ideas by Tang we propose that this type of logarithmic scaling can be explained by a concept of local scaling invariance with continuously varying exponents. The functional dependence of the exponents is constrained by a homomorphism which can be expressed as a set of partial differential equations. Solving these equations we obtain logarithmic scaling as a special case. The other solutions lead to scaling forms where logarithmic and power-law scaling are mixed
17. STRENGTH OF NANOMODIFIED HIGH-STRENGTH LIGHTWEIGHT CONCRETES
Directory of Open Access Journals (Sweden)
NOZEMTСEV Alexandr Sergeevich
2013-02-01
Full Text Available The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensinal modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300…1500 kg/m³ and compressive strength is 40…65 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m³ are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production have been justified.
18. Comparison of Thermal Stability of Dry High-strength Concrete and Wet High-strength Concrete
Science.gov (United States)
Musorina, Tatiana; Katcay, Aleksandr; Selezneva, Anna; Kamskov, Victor
2018-03-01
High-strength concrete is a modern material, which occupies its own niche on the construction material market. It is applicable in a large-scale high-rise construction, particularly an underground construction is a frequently used solution for a space saving. Usually underground structure is related to a wet usage environment. Though not all properties of the high-strength concrete are investigated to the full extent. Under adverse climatic conditions of the Russian Federation one of the most important properties for constructional materials is a thermal capacity. Therefore, the main purpose of the paper is to compare a thermal capacity of the high-strength concrete in humid conditions and a thermal capacity of the high-strength concrete in dry operational condition. During the study dependency between thermal capacity and design wall thickness and ambient humidity has to be proven with two experiments. As a result the theoretical relation between thermal capacity characteristic - thermal inertia and wall thickness and ambient humidity was confirmed by the experimental data. The thermal capacity of a building is in direct ratio to the construction thickness. It follows from the experiments and calculations that wet high-strength concrete has less thermal stability.
19. Effects of Mental Imagery on Muscular Strength in Healthy and Patient Participants: A Systematic Review
Science.gov (United States)
Slimani, Maamer; Tod, David; Chaabene, Helmi; Miarka, Bianca; Chamari, Karim
2016-01-01
sensorimotor activation and physiological responses such as blood pressure, heart rate, and respiration rate. Key points Coupling mental imagery with physical training is the best suited intervention for improving strength performance. An examination of potential moderator variables revealed that the effectiveness of mental imagery on strength performance may vary depending on the appropriate matching of muscular groups, the characteristics of mental imagery interventions, training duration, and type of skills. Self-efficacy, motivation, and imagery ability were the mediator variables in the mental imagery-strength performance relationship. Greater effects of internal imagery perspective on strength performance than those of external imagery could be explained in terms of neural adaptations, stronger brain activation, higher muscles excitation, greater somatic and sensorimotor activation, and higher physiological responses such as blood pressure, heart rate, and respiration rate. Mental imagery prevention interventions may provide a valuable tool to improve the functional recovery after short-term muscle immobilization and anterior cruciate ligament in patients. PMID:27803622
20. Varying constants, black holes, and quantum gravity
International Nuclear Information System (INIS)
Carlip, S.
2003-01-01
Tentative observations and theoretical considerations have recently led to renewed interest in models of fundamental physics in which certain 'constants' vary in time. Assuming fixed black hole mass and the standard form of the Bekenstein-Hawking entropy, Davies, Davis and Lineweaver have argued that the laws of black hole thermodynamics disfavor models in which the fundamental electric charge e changes. I show that with these assumptions, similar considerations severely constrain 'varying speed of light' models, unless we are prepared to abandon cherished assumptions about quantum gravity. Relaxation of these assumptions permits sensible theories of quantum gravity with ''varying constants,'' but also eliminates the thermodynamic constraints, though the black hole mass spectrum may still provide some restrictions on the range of allowable models
1. Fracture Resistance, Surface Defects and Structural Strength of Glass
OpenAIRE
Rodichev, Y.M.; Veer, F.A.
2010-01-01
This paper poses the theory that the fracture resistance of basic float glass is dependent on it physicochemical properties and the surface defects fonned under the float glass production, glass processing and handling at the service conditions compose the aggregate basis for structural glass strength assessment. The effect of loading conditions, constructional and technological factors on the engineering strength of glass can be evaluated in certain cases using fracture mechanics with inform...
2. Strength curves for shales and sandstones under hydrostatic confining pressures
International Nuclear Information System (INIS)
Gupta, S.C.; Sikka, S.K.
1978-01-01
The experimental data for the effect of confining pressures on the fracture stress have been analysed for shales and sandstones. The normalized compressive strengths are found to lie in a narrow region so that Ohnaka's equation for crystalline rocks, can be fitted to the data. The fitted parameters are physically reasonable and indicate that the functional dependence of strength on porosity, strain rate and temperature is independent of the confining pressures. (author)
3. Strength of wood versus rate of testing - A theoretical approach
DEFF Research Database (Denmark)
Nielsen, Lauge Fuglsang
2007-01-01
Strength of wood is normally measured in ramp load experiments. Experience shows that strength increases with increasing rate of testing. This feature is considered theoretically in this paper. It is shown that the influence of testing rate is a phenomenon, which depends on the quality...... of the considered wood. Low quality wood shows lesser influence of testing rate. This observation agrees with the well-known statement made by Borg Madsen that weak wood subjected to a constant load, has a longer lifetime than strong wood. In general, the influence of testing rate on strength increases...
4. Computation of radionuclide particulate finite area fugitive source strengths
Energy Technology Data Exchange (ETDEWEB)
Fields, D E
1983-06-01
Atmospheric source strengths quantifying particulate re-suspension from wind and non-wind disturbance-driven processes are computed for sites of small area. These values are useful in computing downwind air concentration values to evaluate risk to exposed populations. The net source strength for the site is the sum of the wind- and disturbance-driven components. A unified source strength approach includes both classes of re-suspension processes. More research is needed to satisfactorily express the time-dependence of re-suspension parameters, especially in non-arid climates where population densities are greater. (JMT)
5. Improved Ultraviolet and Infrared Oscillator Strengths for OH+
Science.gov (United States)
Hodges, James N.; Bittner, Dror M.; Bernath, Peter F.
2018-03-01
Molecular ions are key reaction intermediates in the interstellar medium. OH+ plays a central role in the formation of more complex chemical species and for estimating the cosmic ray ionization rate in astrophysical environments. Here, we use a recent analysis of a laboratory spectrum in conjunction with ab initio methods to calculate infrared and ultraviolet oscillator strengths. These new oscillator strengths include branch dependent intensity corrections, arising from the Herman–Wallis effect, that have not been included before. We estimate 10% total uncertainty in the UV and 6% total uncertainty in the IR for the oscillator strengths.
6. Effect of Hand Mixing on the Compressive Strength of Concrete
Directory of Open Access Journals (Sweden)
James Isiwu AGUWA
2010-12-01
Full Text Available This paper presents the effect of hand mixing on the compressive strength of concrete. Before designing the concrete mix, sieve analysis of sharp sand and chippings was carried out and their fineness moduli were determined. Also the dry weight of chippings and the specific gravities of both sand and chippings were determined. A designed concrete mix of 1:2:4 was used and the number of turnings of the mixture over from one end to another by hand mixing was varying from one time up to and including seven times. The strengths were measured at the curing ages of 7, 14, 21 and 28 days respectively using 150mm concrete cubes cast, cured and crushed. The results revealed that the compressive strengths of concrete cubes appreciably increased with increase in number of turnings from one to four times but remained almost constant beyond four times of turning for all the ages tested. For example, at 1, 2, and 3 times turning; the compressive strengths at 28 days were 4.67, 13.37 and 20.28N/mm2 respectively while at 4, 5 and 6 times turning; the compressive strengths at 28 days were 21.15, 21.34 and 21.69N/mm2. From the data, adequate strengths were not developed at turnings below three times of hand mixing, concluding that a minimum of three times turning is required to produce concrete with satisfactory strength.
7. Strength Development of High-Strength Ductile Concrete Incorporating Metakaolin and PVA Fibers
Directory of Open Access Journals (Sweden)
2014-01-01
Full Text Available The mechanical properties of high-strength ductile concrete (HSDC have been investigated using Metakaolin (MK as the cement replacing material and PVA fibers. Total twenty-seven (27 mixes of concrete have been examined with varying content of MK and PVA fibers. It has been found that the coarser type PVA fibers provide strengths competitive to control or higher than control. Concrete with coarser type PVA fibers has also refined microstructure, but the microstructure has been undergone with the increase in aspect ratio of fibers. The microstructure of concrete with MK has also more refined and packing of material is much better with MK. PVA fibers not only give higher stiffness but also showed the deflection hardening response. Toughness Index of HSDC reflects the improvement in flexural toughness over the plain concrete and the maximum toughness indices have been observed with 10% MK and 2% volume fraction of PVA fibers.
8. Strength development of high-strength ductile concrete incorporating Metakaolin and PVA fibers.
Science.gov (United States)
2014-01-01
The mechanical properties of high-strength ductile concrete (HSDC) have been investigated using Metakaolin (MK) as the cement replacing material and PVA fibers. Total twenty-seven (27) mixes of concrete have been examined with varying content of MK and PVA fibers. It has been found that the coarser type PVA fibers provide strengths competitive to control or higher than control. Concrete with coarser type PVA fibers has also refined microstructure, but the microstructure has been undergone with the increase in aspect ratio of fibers. The microstructure of concrete with MK has also more refined and packing of material is much better with MK. PVA fibers not only give higher stiffness but also showed the deflection hardening response. Toughness Index of HSDC reflects the improvement in flexural toughness over the plain concrete and the maximum toughness indices have been observed with 10% MK and 2% volume fraction of PVA fibers.
9. Path Dependency
OpenAIRE
Mark Setterfield
2015-01-01
Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.
10. Effects of stacking sequence on impact damage resistance and residual strength for quasi-isotropic laminates
Science.gov (United States)
Dost, Ernest F.; Ilcewicz, Larry B.; Avery, William B.; Coxon, Brian R.
1991-01-01
Residual strength of an impacted composite laminate is dependent on details of the damage state. Stacking sequence was varied to judge its effect on damage caused by low-velocity impact. This was done for quasi-isotropic layups of a toughened composite material. Experimental observations on changes in the impact damage state and postimpact compressive performance were presented for seven different laminate stacking sequences. The applicability and limitations of analysis compared to experimental results were also discussed. Postimpact compressive behavior was found to be a strong function of the laminate stacking sequence. This relationship was found to depend on thickness, stacking sequence, size, and location of sublaminates that comprise the impact damage state. The postimpact strength for specimens with a relatively symmetric distribution of damage through the laminate thickness was accurately predicted by models that accounted for sublaminate stability and in-plane stress redistribution. An asymmetric distribution of damage in some laminate stacking sequences tended to alter specimen stability. Geometrically nonlinear finite element analysis was used to predict this behavior.
11. Características imunológicas e virológicas e as variáveis flexibilidade (FLEX e força de resistência abdominal (FRA de crianças e adolescentes portadores de HIV/AIDS em uso de TARV Immunological and virological characteristics and performance in the variables flexibility and abdominal resistence strength of HIV/AIDS adolescents under highly active antirretroviral therapy
Directory of Open Access Journals (Sweden)
Fabiana Ferreira dos Santos
2013-02-01
12. Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback
Science.gov (United States)
Winnick, Matthew J.; Maher, Kate
2018-03-01
Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. We test this theoretical scaling relationship against reactive transport simulations of chemical weathering profiles under open- and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO2 (y = kxn) where n is dependent on reaction stoichiometry and k is dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO2 at low values and approach open-system scaling at high pCO2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence
13. The Statistical Analysis of Relation between Compressive and Tensile/Flexural Strength of High Performance Concrete
Directory of Open Access Journals (Sweden)
Kępniak M.
2016-12-01
Full Text Available This paper addresses the tensile and flexural strength of HPC (high performance concrete. The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.
14. Towards evidence based strength training: a comparison of muscle forces during deadlifts, goodmornings and split squats.
Science.gov (United States)
Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio
2017-01-01
15. "Mina olin siin" esilinastub Karlovy Varys
Index Scriptorium Estoniae
2008-01-01
Karlovy Vary filmifestivalil esilinastub Rene Vilbre noortefilm "Mina olin siin", mille aluseks on Sass Henno romaan "Mina olin siin. Esimene arest", stsenaariumi kirjutas Ilmar Raag. Film võistleb võistlusprogrammis "East of the West". Esitlema sõidavad R. Vilbre, R. Sildos, R. Kaljujärv, T. Tuisk
16. Tracking time-varying coefficient-functions
DEFF Research Database (Denmark)
Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Joensen, Alfred K.
2000-01-01
is a combination of recursive least squares with exponential forgetting and local polynomial regression. It is argued, that it is appropriate to let the forgetting factor vary with the value of the external signal which is the argument of the coefficient functions. Some of the key properties of the modified method...... are studied by simulation...
17. Filmihullu eluvesi voolab Karlovy Varys / Margit Tõnson
Index Scriptorium Estoniae
Tõnson, Margit, 1978-
2010-01-01
Karlovy Vary rahvusvahelisest filmifestivalist. Filmidest "Mr. Nobody" (rež. Jaco Van Dormaeli), "Kasside ema Teresa" (rež. Pawel Sala) ja "The Arbor" (rež. Clio Barnardi). Nimekiri võitnud töödest ja viimastel aastatel festivalil näidatud Eesti mängufilmidest
18. Ellipsometry with randomly varying polarization states
NARCIS (Netherlands)
Liu, F.; Lee, C. J.; Chen, J. Q.; E. Louis,; van der Slot, P. J. M.; Boller, K. J.; F. Bijkerk,
2012-01-01
We show that, under the right conditions, one can make highly accurate polarization-based measurements without knowing the absolute polarization state of the probing light field. It is shown that light, passed through a randomly varying birefringent material has a well-defined orbit on the Poincar
19. Õunpuu Karlovy Varys edukas
Index Scriptorium Estoniae
2010-01-01
45. Karlovy Vary filmifestivali võistlusprogrammis "East of the West" märgiti ära Veiko Õunpuu film "Püha Tõnu kiusamine". Peaauhind läks rumeenlase Cristi Puiu filmile "Aurora". Grand prix´sai Augustĺ Vila film "La mosquitera". Teisi preemiasaajaid
20. The effect of shredding and test apparatus size on compressibility and strength parameters of degraded municipal solid waste.
Science.gov (United States)
Hossain, M S; Gabr, M A; Asce, F
2009-09-01
In many situations, MSW components are processed and shredded before use in laboratory experiments using conventional soil testing apparatus. However, shredding MSW material may affect the target property to be measured. The objective of this study is to contribute to the understanding of the effect of shredding of MSW on the measured compressibility and strength properties. It is hypothesized that measured properties can be correlated to an R-value, the ratio of waste particle size to apparatus size. Results from oedometer tests, conducted on 63.5 mm, 100 mm, 200 mm diameter apparatus, indicated the dependency of the compressibility parameters on R-value. The compressibility parameters are similar for the same R-value even though the apparatus size varies. The results using same apparatus size with variable R-values indicated that shredding of MSW mainly affects initial compression. Creep and biological strain rate of the tested MSW are not significantly affected by R-value. The shear strength is affected by shredding as the light-weight reinforcing materials are shredded into smaller pieces during specimen preparation. For example, the measured friction angles are 32 degrees and 27 degrees for maximum particle sizes of 50 mm and 25 mm, respectively. The larger MSW components in the specimen provide better reinforcing contribution. This conclusion is however dependent on comparing specimen at the same level of degradation since shear strength is also a function of extent of degradation.
1. Performance of Traffic Noise Barriers with Varying Cross-Section
Directory of Open Access Journals (Sweden)
Sanja Grubeša
2011-05-01
Full Text Available The efficiency of noise barriers largely depends on their geometry. In this paper, the performance of noise barriers was simulated using the numerical Boundary Element Method (BEM. Traffic noise was particularly considered with its standardized noise spectrum adapted to human hearing. The cross-section of the barriers was varied with the goal of finding the optimum shape in comparison to classical rectangular barriers. The barrier performance was calculated at different receiver points for a fixed barrier height and source position. The magnitude of the insertion loss parameter was used to evaluate the performance change, both in one-third octave bands and as the broadband mean insertion loss value. The proposed barriers of varying cross-section were also compared with a typical T-shape barrier of the same height.
2. A Fragment-Cloud Model for Breakup of Asteroids with Varied Internal Structures
Science.gov (United States)
Wheeler, Lorien; Mathias, Donovan; Stokan, Ed; Brown, Peter
2016-01-01
As an asteroid descends toward Earth, it deposits energy in the atmosphere through aerodynamic drag and ablation. Asteroid impact risk assessments rely on energy deposition estimates to predict blast overpressures and ground damage that may result from an airburst, such as the one that occurred over Chelyabinsk, Russia in 2013. The rates and altitudes at which energy is deposited along the entry trajectory depend upon how the bolide fragments, which in turn depends upon its internal structure and composition. In this work, we have developed an analytic asteroid fragmentation model to assess the atmospheric energy deposition of asteroids with a range of structures and compositions. The modeling approach combines successive fragmentation of larger independent pieces with aggregate debris clouds released with each fragmentation event. The model can vary the number and masses of fragments produced, the amount of mass released as debris clouds, the size-strength scaling used to increase the robustness of smaller fragments, and other parameters. The initial asteroid body can be seeded with a distribution of independent fragment sizes amid a remaining debris mass to represent loose rubble pile conglomerations, can be given an outer regolith later, or can be defined as a coherent or fractured monolith. This approach enables the model to represent a range of breakup behaviors and reproduce detailed energy deposition features such as multiple flares due to successive burst events, high-altitude regolith blow-off, or initial disruption of rubble piles followed by more energetic breakup of the constituent boulders. These capabilities provide a means to investigate sensitivities of ground damage to potential variations in asteroid structure.
3. Neuromuscular mechanisms and neural strategies in the control of time-varying muscle contractions.
Science.gov (United States)
Erimaki, Sophia; Agapaki, Orsalia M; Christakos, Constantinos N
2013-09-01
The organization of the neural input to motoneurons that underlies time-varying muscle force is assumed to depend on muscle transfer characteristics and neural strategies or control modes utilizing sensory signals. We jointly addressed these interlinked, but previously studied individually and partially, issues for sinusoidal (range 0.5-5.0 Hz) force-tracking contractions of a human finger muscle. Using spectral and correlation analyses of target signal, force signal, and motor unit (MU) discharges, we studied 1) patterns of such discharges, allowing inferences on the motoneuronal input; 2) transformation of MU population activity (EMG) into quasi-sinusoidal force; and 3) relation of force oscillation to target, carrying information on the input's organization. A broad view of force control mechanisms and strategies emerged. Specifically, synchronized MU and EMG modulations, reflecting a frequency-modulated motoneuronal input, accompanied the force variations. Gain and delay drops between EMG modulation and force oscillation, critical for the appropriate organization of this input, occurred with increasing target frequency. According to our analyses, gain compensation was achieved primarily through rhythmical activation/deactivation of higher-threshold MUs and secondarily through the adaptation of the input's strength expected during tracking tasks. However, the input's timing was not adapted to delay behaviors and seemed to depend on the control modes employed. Thus, for low-frequency targets, the force oscillation was highly coherent with, but led, a target, this timing error being compatible with predictive feedforward control partly based on the target's derivatives. In contrast, the force oscillation was weakly coherent, but in phase, with high-frequency targets, suggesting control mainly based on a target's rhythm.
4. Slowly varying dilaton cosmologies and their field theory duals
International Nuclear Information System (INIS)
Awad, Adel; Das, Sumit R.; Ghosh, Archisman; Oh, Jae-Hyuk; Trivedi, Sandip P.
2009-01-01
We consider a deformation of the AdS 5 xS 5 solution of IIB supergravity obtained by taking the boundary value of the dilaton to be time dependent. The time dependence is taken to be slowly varying on the anti-de Sitter (AdS) scale thereby introducing a small parameter ε. The boundary dilaton has a profile which asymptotes to a constant in the far past and future and attains a minimum value at intermediate times. We construct the supergravity (sugra) solution to first nontrivial order in ε, and find that it is smooth, horizon-free, and asymptotically AdS 5 xS 5 in the far future. When the intermediate values of the dilaton becomes small enough the curvature becomes of order the string scale and the sugra approximation breaks down. The resulting dynamics is analyzed in the dual SU(N) gauge theory on S 3 with a time dependent coupling constant which varies slowly. When Nε 5 xS 5 again. When Nε>>1, we formulate a classical adiabatic perturbation theory based on coherent states which arises in the large N limit. For large values of the 't Hooft coupling this reproduces the supergravity results. For small 't Hooft coupling the coherent state calculations become involved and we cannot reach a definite conclusion. We argue that the final state should have a dual description which is mostly smooth AdS 5 space with the possible presence of a small black hole.
5. Effect of agglomerate strength on sintered density for yttria powders containing agglomerates of monosize spheres
International Nuclear Information System (INIS)
Ciftcioglu, M.; Akine, M.; Burkhart, L.
1987-01-01
The effect of agglomerate strength on sintered density was determined for several yttria powders made by intentionally agglomerating 0.1-μm, monodisperse yttriuim hydrocarbonate precursor spheres and calcining separate portions of the precursor at different temperatures to vary the strength of the intraaglomeate bonds. In this way, the effects of differences in particle morphology and other characteristics among the powders were minimized and the effect of agglomerate strength could be seen more clearly
6. Investigation of the bond strength between the photo-sensitive polymer SU-8 and Au
DEFF Research Database (Denmark)
Nordstrom, Maria; Johansson, Alicia; Sanches-Noguerón, E.
2004-01-01
promotors between the SU-8 and Au (ii) the effect of the processing sequence, either keeping SU-8 as bottum layer or Au (iii) varying the UV exposure dosage of the SU-8. For comparison, also the bond strength between SU-8 and other materials was measured. We report on bond strength of 4.8 +/- 1.2 MPa...
7. Isolated electrostatic structures observed throughout the Cluster orbit: relationship to magnetic field strength
Directory of Open Access Journals (Sweden)
J. S. Pickett
2004-07-01
Full Text Available Isolated electrostatic structures are observed throughout much of the 4RE by 19.6RE Cluster orbit. These structures are observed in the Wideband plasma wave instrument's waveform data as bipolar pulses (one positive and one negative peak in the electric field amplitude and tripolar pulses (two positive and one negative peak, or vice versa. These structures are observed at all of the boundary layers, in the solar wind and magnetosheath, and along auroral field lines at 4.5-6.5RE. Using the Wideband waveform data from the various Cluster spacecraft we have carried out a survey of the amplitudes and time durations of these structures and how these quantities vary with the local magnetic field strength. Such a survey has not been carried out before, and it reveals certain characteristics of solitary structures in a finite magnetic field, a topic still inadequately addressed by theories. We find that there is a broad range of electric field amplitudes at any specific magnetic field strength, and there is a general trend for the electric field amplitudes to increase as the strength of the magnetic field increases over a range of 5 to 500nT. We provide a possible explanation for this trend that relates to the structures being Bernstein-Greene-Kruskal mode solitary waves. There is no corresponding dependence of the duration of the structures on the magnetic field strength, although a plot of these two quantities reveals the unexpected result that with the exception of the magnetosheath, all of the time durations for all of the other regions are comparable, whereas the magnetosheath time durations clearly are in a different category of much smaller time duration. We speculate that this implies that the structures are much smaller in size. The distinctly different pulse durations for the magnetosheath pulses indicate the possibility that the pulses are generated by a mechanism which is different from the mechanism operating in other regions.
8. A systematic review of consumer preference for e-cigarette attributes: Flavor, nicotine strength, and type
Science.gov (United States)
Nemati, Mehdi; Zheng, Yuqing
2018-01-01
Objective Systematic review of research examining consumer preference for the main electronic cigarette (e-cigarette) attributes namely flavor, nicotine strength, and type. Method A systematic search of peer-reviewed articles resulted in a pool of 12,933 articles. We included only articles that meet all the selection criteria: (1) peer-reviewed, (2) written in English, and (3) addressed consumer preference for one or more of the e-cigarette attributes including flavor, strength, and type. Results 66 articles met the inclusion criteria for this review. Consumers preferred flavored e-cigarettes, and such preference varied with age groups and smoking status. We also found that several flavors were associated with decreased harm perception while tobacco flavor was associated with increased harm perception. In addition, some flavor chemicals and sweeteners used in e-cigarettes could be of toxicological concern. Finally, consumer preference for nicotine strength and types depended on smoking status, e-cigarette use history, and gender. Conclusion Adolescents could consider flavor the most important factor trying e-cigarettes and were more likely to initiate vaping through flavored e-cigarettes. Young adults overall preferred sweet, menthol, and cherry flavors, while non-smokers in particular preferred coffee and menthol flavors. Adults in general also preferred sweet flavors (though smokers like tobacco flavor the most) and disliked flavors that elicit bitterness or harshness. In terms of whether flavored e-cigarettes assisted quitting smoking, we found inconclusive evidence. E-cigarette users likely initiated use with a cigarette like product and transitioned to an advanced system with more features. Non-smokers and inexperienced e-cigarettes users tended to prefer no nicotine or low nicotine e-cigarettes while smokers and experienced e-cigarettes users preferred medium and high nicotine e-cigarettes. Weak evidence exists regarding a positive interaction between menthol
9. A systematic review of consumer preference for e-cigarette attributes: Flavor, nicotine strength, and type.
Science.gov (United States)
Zare, Samane; Nemati, Mehdi; Zheng, Yuqing
2018-01-01
Systematic review of research examining consumer preference for the main electronic cigarette (e-cigarette) attributes namely flavor, nicotine strength, and type. A systematic search of peer-reviewed articles resulted in a pool of 12,933 articles. We included only articles that meet all the selection criteria: (1) peer-reviewed, (2) written in English, and (3) addressed consumer preference for one or more of the e-cigarette attributes including flavor, strength, and type. 66 articles met the inclusion criteria for this review. Consumers preferred flavored e-cigarettes, and such preference varied with age groups and smoking status. We also found that several flavors were associated with decreased harm perception while tobacco flavor was associated with increased harm perception. In addition, some flavor chemicals and sweeteners used in e-cigarettes could be of toxicological concern. Finally, consumer preference for nicotine strength and types depended on smoking status, e-cigarette use history, and gender. Adolescents could consider flavor the most important factor trying e-cigarettes and were more likely to initiate vaping through flavored e-cigarettes. Young adults overall preferred sweet, menthol, and cherry flavors, while non-smokers in particular preferred coffee and menthol flavors. Adults in general also preferred sweet flavors (though smokers like tobacco flavor the most) and disliked flavors that elicit bitterness or harshness. In terms of whether flavored e-cigarettes assisted quitting smoking, we found inconclusive evidence. E-cigarette users likely initiated use with a cigarette like product and transitioned to an advanced system with more features. Non-smokers and inexperienced e-cigarettes users tended to prefer no nicotine or low nicotine e-cigarettes while smokers and experienced e-cigarettes users preferred medium and high nicotine e-cigarettes. Weak evidence exists regarding a positive interaction between menthol flavor and nicotine strength.
10. Strength Training and Your Child
Science.gov (United States)
... in organized sports or activities such as baseball, soccer, or gymnastics usually can safely to start strength ... as biking and running, adequate hydration, and healthy nutrition. Reviewed by: Mary L. Gavin, MD Date reviewed: ...
11. Diffusion with Varying Drag; the Runaway Problem.
Science.gov (United States)
Rollins, David Kenneth
We study the motion of electrons in an ionized plasma of electrons and ions in an external electric field. A probability distribution function describes the electron motion and is a solution of a Fokker-Planck equation. In zero field, the solution approaches an equilibrium Maxwellian. For arbitrarily small field, electrons overcome the diffusive effects and are freely accelerated by the field. This is the electron runaway phenomenon. We treat the electric field as a small perturbation. We consider various diffusion coefficients for the one dimensional problem and determine the runaway current as a function of the field strength. Diffusion coefficients, non-zero on a finite interval are examined. Some non-trivial cases of these can be solved exactly in terms of known special functions. The more realistic case where the diffusion coefficient decays with velocity are then considered. To determine the runaway current, the equivalent Schrodinger eigenvalue problem is analysed. The smallest eigenvalue is shown to be equal to the runaway current. Using asymptotic matching a solution can be constructed which is then used to evaluate the runaway current. The runaway current is exponentially small as a function of field strength. This method is used to extract results from the three dimensional problem.
12. Diffusion with varying drag; the runaway problem
International Nuclear Information System (INIS)
Rollins, D.K.
1986-01-01
The motion of electrons in an ionized plasma of electrons and ions in an external electric field is studied. A probability distribution function describes the electron motion and is a solution of a Fokker-Planck equation. In zero field, the solution approaches an equilibrium Maxwellian. For arbitrarily small field, electrons overcome the diffusive effects and are freely accelerated by the field. This is the electron-runaway phenomenon. The electric field is treated as a small perturbation. Various diffusion coefficients are considered for the one dimensional problem, and the runaway current is determined as a function of the field strength. Diffusion coefficients, non-zero on a finite interval are examined. Some non-trivial cases of these can be solved exactly in terms of known special functions. The more realistic case where the diffusion coeffient decays with velocity are then considered. To determine the runaway current, the equivalent Schroedinger eigenvalue problem is analyzed. The smallest eigenvalue is shown to be equal to the runaway current. Using asymptotic matching, a solution can be constructed which is then used to evaluate the runaway current. The runaway current is exponentially small as a function of field strength. This method is used to extract results from the three dimensional problem
13. Theoretical predictions for alpha particle spectroscopic strengths
International Nuclear Information System (INIS)
Draayer, J.P.
1975-01-01
Multinucleon transfers induced in heavy-ion reactions of the type ( 6 Li,d) furnish a selective probe with which to study the interplay between rotational and clustering phenomena so characteristic of the structure of the light sd-shell nuclei. For these nuclei, theoretical predictions for inter-band as well as intra-band transfer strengths can be made using recently tabulated results for angular momentum dependent SU 3 inclusion R 3 relative spectroscopic strengths and angular momentum independent SU 6 inclusion SU 3 coefficients of fractional parentage. The pure SU 3 (oscillator)-SU 4 (supermultiplet) symmetry limit agrees well with results obtained using available eigenfunctions determined in large shell model calculations. In particular, the scalar nature of a transferred ''alpha''-cluster insures that the effect of spatial symmetry admixtures in the initial and final states of the target and residual nuclei are minimized. Sum rule quantities provide a measure of the probable effects of symmetry breaking. Strength variations within a band are expected; transfers to core excited states are often favored. Results extracted from exact finite range DWBA analyses of ( 6 Li,d) data on 16 , 18 O, 20 , 21 , 22 Ne, 24 , 25 Mg show some anomalies in our understanding of the structure and/or reaction mechanisms. (18 figures) (U.S.)
14. Characteristics of structural loess strength and preliminary framework for joint strength formula
OpenAIRE
Rong-jian Li; Jun-ding Liu; Rui Yan; Wen Zheng; Sheng-jun Shao
2014-01-01
The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress (Kf line), and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests: the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural lo...
15. Epidemic spreading in time-varying community networks.
Science.gov (United States)
Ren, Guangming; Wang, Xingyuan
2014-06-01
The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q epidemic spreading in complex networks with community structure.
16. Varied line-space gratings and applications
International Nuclear Information System (INIS)
McKinney, W.R.
1991-01-01
This paper presents a straightforward analytical and numerical method for the design of a specific type of varied line-space grating system. The mathematical development will assume plane or nearly-plane spherical gratings which are illuminated by convergent light, which covers many interesting cases for synchrotron radiation. The gratings discussed will have straight grooves whose spacing varies across the principal plane of the grating. Focal relationships and formulae for the optical grating-pole-to-exist-slit distance and grating radius previously presented by other authors will be derived with a symbolic algebra system. It is intended to provide the optical designer with the tools necessary to design such a system properly. Finally, some possible advantages and disadvantages for application to synchrotron to synchrotron radiation beamlines will be discussed
17. The Thermal Collector With Varied Glass Covers
International Nuclear Information System (INIS)
Luminosu, I.; Pop, N.
2010-01-01
The thermal collector with varied glass covers represents an innovation realized in order to build a collector able to reach the desired temperature by collecting the solar radiation from the smallest surface, with the highest efficiency. In the case of the thermal collector with variable cover glasses, the number of the glass plates covering the absorber increases together with the length of the circulation pipe for the working fluid. The thermal collector with varied glass covers compared to the conventional collector better meet user requirements because: for the same temperature increase, has the collecting area smaller; for the same collection area, realizes the highest temperature increase and has the highest efficiency. This works is addressed to researchers in the solar energy and to engineers responsible with air-conditioning systems design or industrial and agricultural products drying.
18. Compresive Strength for FRC Member using Silica Fume
OpenAIRE
R.M.Damgir,; Y.M.Ghugal
2011-01-01
The compressive strength of concrete was obtained by conducting tests on standard cubes of size 150X 150X150 mm size with fibers 0 to 5% with an increment of 0.5% and Silica Fume of 5%.The compressivestrength was determined by carrying out compressive test by using UTM. Slump loss increases with increase in Fiber Volume Crack Width reduces as percentage Fiber Volume increases and Crack width varying between 0.75 to 1.30 mm for 28 days concrete strength. Toughness of concrete member increases ...
19. Spatially varying dispersion to model breakthrough curves.
Science.gov (United States)
Li, Guangquan
2011-01-01
Often the water flowing in a karst conduit is a combination of contaminated water entering at a sinkhole and cleaner water released from the limestone matrix. Transport processes in the conduit are controlled by advection, mixing (dilution and dispersion), and retention-release. In this article, a karst transport model considering advection, spatially varying dispersion, and dilution (from matrix seepage) is developed. Two approximate Green's functions are obtained using transformation of variables, respectively, for the initial-value problem and for the boundary-value problem. A numerical example illustrates that mixing associated with strong spatially varying conduit dispersion can cause strong skewness and long tailing in spring breakthrough curves. Comparison of the predicted breakthrough curve against that measured from a dye-tracing experiment between Ames Sink and Indian Spring, Northwest Florida, shows that the conduit dispersivity can be as large as 400 m. Such a large number is believed to imply strong solute interaction between the conduit and the matrix and/or multiple flow paths in a conduit network. It is concluded that Taylor dispersion is not dominant in transport in a karst conduit, and the complicated retention-release process between mobile- and immobile waters may be described by strong spatially varying conduit dispersion. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.
20. Kairomonal communication in mice is concentration-dependent with a proportional discrimination threshold [v2; ref status: indexed, http://f1000r.es/2h5
Directory of Open Access Journals (Sweden)
Anand Vasudevan
2013-12-01
Full Text Available Odors of predators are often co-opted by prey species to serve as warning signals. Perceptual properties of such kairomonal communication are under studied despite their common use in many mammals. We demonstrate that the kairomonal response in mice to rat odors varies monotonically with the volume of rat odor. Moreover, the ability of mice to differentiate between two strengths of rat odors is dependent on the ratio of the two concentrations. These results show that mice can compare kairomonal strength over a large range of values, and that kairomonal communication follows Weber’s law.
1. High-strength cellular ceramic composites with 3D microarchitecture.
Science.gov (United States)
Bauer, Jens; Hengsbach, Stefan; Tesari, Iwiza; Schwaiger, Ruth; Kraft, Oliver
2014-02-18
To enhance the strength-to-weight ratio of a material, one may try to either improve the strength or lower the density, or both. The lightest solid materials have a density in the range of 1,000 kg/m(3); only cellular materials, such as technical foams, can reach considerably lower values. However, compared with corresponding bulk materials, their specific strength generally is significantly lower. Cellular topologies may be divided into bending- and stretching-dominated ones. Technical foams are structured randomly and behave in a bending-dominated way, which is less weight efficient, with respect to strength, than stretching-dominated behavior, such as in regular braced frameworks. Cancellous bone and other natural cellular solids have an optimized architecture. Their basic material is structured hierarchically and consists of nanometer-size elements, providing a benefit from size effects in the material strength. Designing cellular materials with a specific microarchitecture would allow one to exploit the structural advantages of stretching-dominated constructions as well as size-dependent strengthening effects. In this paper, we demonstrate that such materials may be fabricated. Applying 3D laser lithography, we produced and characterized micro-truss and -shell structures made from alumina-polymer composite. Size-dependent strengthening of alumina shells has been observed, particularly when applied with a characteristic thickness below 100 nm. The presented artificial cellular materials reach compressive strengths up to 280 MPa with densities well below 1,000 kg/m(3).
2. Strength and lifetime of polymer glasses
Energy Technology Data Exchange (ETDEWEB)
Bartenev, G.M.; Kartasov, E.M.
1981-03-01
A kinetic equation of the time-dependence of strength (complete isotherm of lifetime) of polymer glasses at stress values ranging from the limiting stress of the occurence of separation breaks to the critical stress is derived. The curvature of lifetime plots occuring at low and high periods of time in the experiments are considered. The ranges of noncritical state, breaks caused by a thermofluctuation mechanism, a transition range and athermal breaks are discerned. The limitations of applicability of the basic empirical equation of the kinetic theory of the time-dependence of strength are explained. Theoretical equations are suggested for calculating various characteristics of the brittle break, as limiting stress and critical stress, relative critical craze length and coefficient of stress concentration at the craze tip with respect to various geometrical configurations of the craze and its position in the sample. With polymethylmethacrylate as an example in the brittle and quasi-brittle state, as characterized by the transition from the rupture of sets of chemical bonds to individual chemical bonds, the thermofluctuation processes of break in polymer glasses are discussed. The application of the thermofluctuation theory of solids to the quasi-brittle fracture is considered. The growth kinetics of crazes and the corresponding equation of lifetime were found to be described by identical (corresponding) analytical expressions by which the changes of the coefficients of stress concentration in the range of microplastic deformation in front of the growing is covered within a wide region of temperature including the brittle temperature.
3. Dependent Classes
DEFF Research Database (Denmark)
Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus
2007-01-01
of dependent classes and a machine-checked type soundness proof in Isabelle/HOL [29], the first of this kind for a language with virtual classes and path-dependent types. [29] T.Nipkow, L.C. Poulson, and M. Wenzel. Isabelle/HOL -- A Proof Assistant for Higher-Order Logic, volume 2283 of LNCS, Springer, 2002......Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...
4. Exercise Dependence
Directory of Open Access Journals (Sweden)
Erdal Vardar
2012-06-01
Full Text Available Exercise dependence define a condition in which a person performs excessive exercise resulting in deterioration of his or her physical and mental health wellness. Despite many clinical research studies on exercise dependence, exact diagnostic criteria has not been developed yet. Clinical evidences concerning etiology, epidemiology, underlying mechanisms and treatment of exercise dependence are still not sufficient. Moreover, evaluation of this clinical disorder within dependency perspective is a fairly new concept. Recent studies have shown that exercise dependence has similar features like chemical substance dependence with regards to withdrawal and tolerance symptoms. The aim of this review was to briefly evaluate diagnostic and clinical features of exercise dependence. [Archives Medical Review Journal 2012; 21(3.000: 163-173
5. Strength of tensed and compressed concrete segments in crack spacing under short-term dynamic load
Directory of Open Access Journals (Sweden)
Galyautdinov Zaur
2018-01-01
Full Text Available Formation of model describing dynamic straining of reinforced concrete requires taking into account the basic aspects influencing the stress-strain state of structures. Strength of concrete segments in crack spacing is one of the crucial aspects that affect general strain behavior of reinforced concrete. Experimental results demonstrate significant change in strength of tensed and compressed concrete segments in crack spacing both under static and under dynamic loading. In this case, strength depends on tensile strain level and the slope angle of rebars towards the cracks direction. Existing theoretical and experimental studies estimate strength of concrete segments in crack spacing under static loading. The present work presents results of experimental and theoretical studies of dynamic strength of plates between cracks subjected to compression-tension. Experimental data was analyzed statistically; the dependences were suggested to describe dynamic strength of concrete segments depending on tensile strain level and slope angle of rebars to cracks direction.
6. Evaluation of Compressive Strength and Sorption/Solubility of Four Luting Cements
Directory of Open Access Journals (Sweden)
Tavangar MS
2017-06-01
Full Text Available Abstract: Statement of Problem: Compressive strength (CS and sorption/solubility of the luting cements are two associated factors. Searching a correlation between sorption/solubility and compressive strength of various luting cements is required. Objectives: To measure the water sorption/solubility, and compressive strength of three resin-based and one conventional glass ionomer (CGI luting cement after 1 and 24 h of immersion in distilled water and to determine if there is any correlation between those properties found. Materials and Methods: Four luting cements were investigated. For each material, 10 disc shaped specimens were prepared for measuring the sorption/solubility. The specimens were cured according to the manufacturer’s instructions, and the sorption/solubility were measured in accordance with the ISO 4049’s. For testing the compression strength, for each material 16 cylindrical specimens were prepared by insertion of cements into a stainless steel split mould. The specimens were cured, divided into groups of 8, and then stored in distilled water at (37 ± 1°C for 1 and 24 h. The test was performed using the universal testing machine, the maximum load was recorded and CS was calculated. The data were analysed using SPSS software version 18. One-way ANOVA, post-hoc Tukey’s test and Pearson’s correlation coefficient were performed. Results: G-CEM had the highest mean CS (153.60± 25.15 and CGI luting had the lowest CS (21.36±5.37 (p 0.05. The lowest mean sorption/solubility value was for RelyXTM U200 and Panavia F, and the highest for CGI luting (all p < 0.001. Conclusions: The compressive strength of all cements did not necessarily increase after 24 h and varied depending on the materials. There was a strong reverse correlation between sorption and CS values after both 1 and 24 h immersion. It may be practical for clinician to use those cements with the less sorption / solubility and more stable compression strength over
7. Edge Modeling by Two Blur Parameters in Varying Contrasts.
Science.gov (United States)
Seo, Suyoung
2018-06-01
This paper presents a method of modeling edge profiles with two blur parameters, and estimating and predicting those edge parameters with varying brightness combinations and camera-to-object distances (COD). First, the validity of the edge model is proven mathematically. Then, it is proven experimentally with edges from a set of images captured for specifically designed target sheets and with edges from natural images. Estimation of the two blur parameters for each observed edge profile is performed with a brute-force method to find parameters that produce global minimum errors. Then, using the estimated blur parameters, actual blur parameters of edges with arbitrary brightness combinations are predicted using a surface interpolation method (i.e., kriging). The predicted surfaces show that the two blur parameters of the proposed edge model depend on both dark-side edge brightness and light-side edge brightness following a certain global trend. This is similar across varying CODs. The proposed edge model is compared with a one-blur parameter edge model using experiments of the root mean squared error for fitting the edge models to each observed edge profile. The comparison results suggest that the proposed edge model has superiority over the one-blur parameter edge model in most cases where edges have varying brightness combinations.
8. Lifting strength in two-person teamwork.
Science.gov (United States)
Lee, Tzu-Hsien
2016-01-01
This study examined the effects of lifting range, hand-to-toe distance, and lifting direction on single-person lifting strengths and two-person teamwork lifting strengths. Six healthy males and seven healthy females participated in this study. Two-person teamwork lifting strengths were examined in both strength-matched and strength-unmatched groups. Our results showed that lifting strength significantly decreased with increasing lifting range or hand-to-toe distance. However, lifting strengths were not affected by lifting direction. Teamwork lifting strength did not conform to the law of additivity for both strength-matched and strength-unmatched groups. In general, teamwork lifting strength was dictated by the weaker of the two members, implying that weaker members might be exposed to a higher potential danger in teamwork exertions. To avoid such overexertion in teamwork, members with significantly different strength ability should not be assigned to the same team.
9. 15N NMR spectroscopic investigation of nitrous and nitric acids in sulfuric acid solutions of varying acidities
International Nuclear Information System (INIS)
Prakash, G.K.S.; Heiliger, L.; Olah, G.A.
1990-01-01
Both nitrous and nitric acids were studied in sulfuric acid solutions of varying acid strengths by 15 N NMR spectroscopy. The study gives new insights into the nature of intermediates present at different acid strengths. Furthermore, we have also discovered a novel redox reaction between NO 2 + and NO + ions involving the intermediacy of their respective acids. A mechanism is proposed to explain the observed results. 13 refs., 2 figs., 1 tab
10. Progress on MEVVA source VARIS at GSI
Science.gov (United States)
2018-05-01
For the last few years, the development of the VARIS (vacuum arc ion source) was concentrated on several aspects. One of them was the production of high current ion beams of heavy metals such as Au, Pb, and Bi. The requested ion charge state for these ion species is 4+. This is quite challenging to produce in vacuum arc driven sources for reasonable beam pulse length (>120 µs) due to the physical properties of these elements. However, the situation can be dramatically improved by using the composite materials or alloys with enhanced physical properties of the cathodes. Another aspect is an increase of the beam brilliance for intense U4+ beams by the optimization of the geometry of the extraction system. A new 7-hole triode extraction system allows an increase of the extraction voltage from 30 kV to 40 kV and also reduces the outer aperture of the extracted ion beam. Thus, a record beam brilliance for the U4+ beam in front of the RFQ (Radio-Frequency Quadrupole) has been achieved, exceeding the RFQ space charge limit for an ion current of 15 mA. Several new projectiles in the middle-heavy region have been successfully developed from VARIS to fulfill the requirements of the future FAIR (Facility for Antiproton and Ion Research) programs. An influence of an auxiliary gas on the production performance of certain ion charge states as well as on operation stability has been investigated. The optimization of the ion source parameters for a maximum production efficiency and highest particle current in front of the RFQ has been performed. The next important aspect of the development will be the increase of the operation repetition rate of VARIS for all elements especially for uranium to 2.7 Hz in order to provide the maximum availability of high current ion beams for future FAIR experiments.
11. Penetrator strength effect in long-rod critical ricochet angle
International Nuclear Information System (INIS)
Daneshjou, K.; Shahravi, M.
2008-01-01
3D numerical simulations were performed in order to further investigate the role of penetrator strength in the interaction of long-rods and oblique targets. Three distinctive regimes resulting from oblique impact depending on the obliquity, namely simple ricochet, critical ricochet and target perforation, were investigated in detail. Critical ricochet angles were calculated with a full 3D explicit finite element method for various impact velocities and strength of target plates and projectiles. Numerical predictions were compared with existing two-dimensional analytical models and test results. It was predicted that critical ricochet angle increases with decreasing impact velocity and that higher ricochet angles were expected if higher strength target materials are employed. But there are differences between analytical models and 3D numerical simulation results or test results. The causes for these discrepancies are established by numerical simulations which explore the validity of the penetrator strength parameter in the analytical model as a physical entity. As a matter of fact, in this paper we first investigate the role of penetrator dynamic strength using two-dimensional simulation which resulted in different penetrator strengths out of different impact velocities. Next, by applying these amounts for penetrator strength in Rosenberg analytical model the critical ricochet angle is calculated. Finally, a comparison between the present analytical method with the 3D simulation and test results shows that the new analytical approach leads to modified results with respect to Rosenberg ones
International Nuclear Information System (INIS)
Joshi, K.D.; Rav, Amit S.; Sur, Amit; Kaushik, T.C.; Gupta, Satish C.
2016-04-01
Spall fracture strength and dynamic yield strength of aluminium alloys have been measured at high strain rates generated in plate impact experiments carried out at different impact velocities ranging from 174 m/s to 560 m/s using single stage gas gun facility. In each experiment, the free surface velocity history of the sample plate of aluminium alloy has been derived from time resolved Doppler shift measured employing indigenously developed velocity interferometer system for any reflector (VISAR). The free surface velocity history so determined has been used to evaluate the spall fracture strength and dynamic yield strength of the target material. The two kinds of alloys of aluminium namely Al2014-T4 and Al2024-T4 have been investigated in these experiments. In Al2014-T4 target plates, the spall strength determined from free surface velocity history recorded for impact velocities of 179 m/s, 307 m/s, 398 m/s and 495m/s is 0.90 GPa, 0.96 GPa, 1.0 GPa and 1.1 GPa, respectively. The average strain rates just ahead of spall pulse have been found to vary from ∼ 1.1×10 4 /s to 2.4×10 4 /s. The dynamic yield strength derived from the measured Hugoniot elastic limit ranges from 0.36 GPa to 0.40 GPa. The spall strength for Al2024-T4 samples has been determined to be 1.11 GPa, 1.18 GPa and 1.42 GPa, at impact velocities of 174 m/s, 377 m/s and 560 m/s, respectively. The corresponding average strain rates range from 1.9×104/s to 2.5×104/s. The dynamic yield strength of Al2024-T4 at these impact velocities has been found to vary from 0.37 GPa to 0.43 GPa. The measured spall strengths in all these experiments are higher than the quasi-static value of 0.511 GPa for Al2014-T4 and 0.470 GPa for Al2024. Similarly, the dynamic yield strengths are also larger than the quasi-static value of 0.355 GPa for Al2014-T4 and 0.360 GPa for Al2024-T4. These experimental studies suggest that at high strain rates, both the alloys of aluminium offer higher resistance against the tensile
13. Conceptual Modeling of Time-Varying Information
DEFF Research Database (Denmark)
Gregersen, Heidi; Jensen, Christian S.
2004-01-01
A wide range of database applications manage information that varies over time. Many of the underlying database schemas of these were designed using the Entity-Relationship (ER) model. In the research community as well as in industry, it is common knowledge that the temporal aspects of the mini......-world are important, but difficult to capture using the ER model. Several enhancements to the ER model have been proposed in an attempt to support the modeling of temporal aspects of information. Common to the existing temporally extended ER models, few or no specific requirements to the models were given...
14. A time-varying magnetic flux concentrator
International Nuclear Information System (INIS)
Kibret, B; Premaratne, M; Lewis, P M; Thomson, R; Fitzgerald, P B
2016-01-01
It is known that diverse technological applications require the use of focused magnetic fields. This has driven the quest for controlling the magnetic field. Recently, the principles in transformation optics and metamaterials have allowed the realization of practical static magnetic flux concentrators. Extending such progress, here, we propose a time-varying magnetic flux concentrator cylindrical shell that uses electric conductors and ferromagnetic materials to guide magnetic flux to its center. Its performance is discussed based on finite-element simulation results. Our proposed design has potential applications in magnetic sensors, medical devices, wireless power transfer, and near-field wireless communications. (paper)
15. Linear Parameter Varying Control of Induction Motors
DEFF Research Database (Denmark)
Trangbæk, Klaus
The subject of this thesis is the development of linear parameter varying (LPV) controllers and observers for control of induction motors. The induction motor is one of the most common machines in industrial applications. Being a highly nonlinear system, it poses challenging control problems...... for high performance applications. This thesis demonstrates how LPV control theory provides a systematic way to achieve good performance for these problems. The main contributions of this thesis are the application of the LPV control theory to induction motor control as well as various contributions...
16. IMPACT STRENGTH AND FAILURE ANALYSIS OF WELDED DAMASCUS STEEL
Directory of Open Access Journals (Sweden)
Rastislav Mintách
2012-01-01
Full Text Available The aim of this work was the experimental research of damascus steel from point of view of the structural analyze, impact strength and failure analyzes. The damascus steel was produced by method of forged welding from STN 41 4260 spring steel and STN 41 9312 tool steel. The damascus steel consisted of both 84 and 168 layers. The impact strength was experimentally determined for original steels and damascus steels after heat treatment in dependence on temperature in the range from -60 to 160 °C. It has been found that the impact strength of experimental steels decreased with decreasing temperature behind with correlated change of damage mode. In the case of experimental tests performed at high temperature ductile fracture was revealed and with decreasing temperature proportion of cleavage facets increased. Only the STN 41 9312 steel did not show considerable difference in values of the impact strength with changing temperature.
17. Student throughput variables and properties: Varying cohort sizes
Directory of Open Access Journals (Sweden)
Lucas C.A. Stoop
2017-11-01
Full Text Available A recent research paper described how student throughput variables and properties combine to explain the behaviour of stationary or simplified throughput systems. Such behaviour can be understood in terms of the locus of a point in the triangular admissible region of the H-S plane, where H represents headcounts and S successful credits, each depending on the system properties at that point. The efficiency of the student throughput process is given by the ratio S/H. Simplified throughput systems are characterised by stationary graduation and dropout patterns of students as well as by annual intakes of student cohorts of equal size. The effect of varying the size of the annual intakes of student cohorts is reported on here. The observations made lead to the establishment of a more generalised student throughput theory which includes the simplified theory as a special case. The generalised theory still retains the notion of a triangular admissible region in the H-S plane but with the size and shape of the triangle depending on the size of the student cohorts. The ratio S/H again emerges as the process efficiency measure for throughput systems in general with unchanged roles assigned to important system properties. This theory provides for a more fundamental understanding of student throughput systems encountered in real life. Significance: A generalised stationary student throughput theory through varying cohort sizes allows for a far better understanding of real student throughput systems.
18. Joint route planning under varying market conditions
NARCIS (Netherlands)
Cruijssen, Frans; Bräysy, Olli; Dullaert, Wout; Fleuren, Hein; Salomon, Marc
2007-01-01
Purpose - To provide empirical evidence on the level of savings that can be attained by joint route planning and how these savings depend on specific market characteristics. Design/methodology/approach - Joint route planning is a measure that companies can take to decrease the costs of their
19. Varying prior information in Bayesian inversion
International Nuclear Information System (INIS)
Walker, Matthew; Curtis, Andrew
2014-01-01
Bayes' rule is used to combine likelihood and prior probability distributions. The former represents knowledge derived from new data, the latter represents pre-existing knowledge; the Bayesian combination is the so-called posterior distribution, representing the resultant new state of knowledge. While varying the likelihood due to differing data observations is common, there are also situations where the prior distribution must be changed or replaced repeatedly. For example, in mixture density neural network (MDN) inversion, using current methods the neural network employed for inversion needs to be retrained every time prior information changes. We develop a method of prior replacement to vary the prior without re-training the network. Thus the efficiency of MDN inversions can be increased, typically by orders of magnitude when applied to geophysical problems. We demonstrate this for the inversion of seismic attributes in a synthetic subsurface geological reservoir model. We also present results which suggest that prior replacement can be used to control the statistical properties (such as variance) of the final estimate of the posterior in more general (e.g., Monte Carlo based) inverse problem solutions. (paper)
20. Brown Dwarf Variability: What's Varying and Why?
Science.gov (United States)
Marley, Mark Scott
2014-01-01
Surveys by ground based telescopes, HST, and Spitzer have revealed that brown dwarfs of most spectral classes exhibit variability. The spectral and temporal signatures of the variability are complex and apparently defy simplistic classification which complicates efforts to model the changes. Important questions include understanding if clearings are forming in an otherwise uniform cloud deck or if thermal perturbations, perhaps associated with breaking gravity waves, are responsible. If clouds are responsible how long does it take for the atmospheric thermal profile to relax from a hot cloudy to a cooler cloudless state? If thermal perturbations are responsible then what atmospheric layers are varying? How do the observed variability timescales compare to atmospheric radiative, chemical, and dynamical timescales? I will address such questions by presenting modeling results for time-varying partly cloudy atmospheres and explore the importance of various atmospheric processes over the relevant timescales for brown dwarfs of a range of effective temperatures. Regardless of the origin of the observed variability, the complexity seen in the atmospheres of the field dwarfs hints at the variability that we may encounter in the next few years in directly imaged young Jupiters. Thus understanding the nature of variability in the field dwarfs, including sensitivity to gravity and metallicity, is of particular importance for exoplanet characterization.
1. Size dependence of elastic mechanical properties of nanocrystalline aluminum
Energy Technology Data Exchange (ETDEWEB)
Xu, Wenwu; Dávila, Lilian P., E-mail: [email protected]
2017-04-24
The effect of grain size on the elastic mechanical properties of nanocrystalline pure metal Al is quantified by molecular dynamics simulation method. In this work, the largest nanocrystalline Al sample has a mean grain size of 29.6 nm and contains over 100 millions atoms in the modeling system. The simulation results show that the elastic properties including elastic modulus and ultimate tensile strength of nanocrystalline Al are relatively insensitive to the variation of mean grain size above 13 nm yet they become distinctly grain size dependent below 13 nm. Moreover, at a grain size <13 nm, the elastic modulus decreases monotonically with decreasing grain size while the ultimate tensile strength of nanocrystalline Al initially decreases with the decrease of the grain size down to 9 nm and then increases with further reduction of grain size. The increase of ultimate tensile strength below 9 nm is believed to be a result of an extended elasticity in the ultrafine grain size nanocrystalline Al. This study can facilitate the prediction of varied mechanical properties for similar nanocrystalline materials and even guide testing and fabrication schemes of such materials.
2. Brazilian Soybean Yields and Yield Gaps Vary with Farm Size
Science.gov (United States)
Jeffries, G. R.; Cohn, A.; Griffin, T. S.; Bragança, A.
2017-12-01
Understanding the farm size-specific characteristics of crop yields and yield gaps may help to improve yields by enabling better targeting of technical assistance and agricultural development programs. Linking remote sensing-based yield estimates with property boundaries provides a novel view of the relationship between farm size and yield structure (yield magnitude, gaps, and stability over time). A growing literature documents variations in yield gaps, but largely ignores the role of farm size as a factor shaping yield structure. Research on the inverse farm size-productivity relationship (IR) theory - that small farms are more productive than large ones all else equal - has documented that yield magnitude may vary by farm size, but has not considered other yield structure characteristics. We examined farm size - yield structure relationships for soybeans in Brazil for years 2001-2015. Using out-of-sample soybean yield predictions from a statistical model, we documented 1) gaps between the 95th percentile of attained yields and mean yields within counties and individual fields, and 2) yield stability defined as the standard deviation of time-detrended yields at given locations. We found a direct relationship between soy yields and farm size at the national level, while the strength and the sign of the relationship varied by region. Soybean yield gaps were found to be inversely related to farm size metrics, even when yields were only compared to farms of similar size. The relationship between farm size and yield stability was nonlinear, with mid-sized farms having the most stable yields. The work suggests that farm size is an important factor in understanding yield structure and that opportunities for improving soy yields in Brazil are greatest among smaller farms.
3. Withdrawal Strength and Bending Yield Strength of Stainless Steel Nails
Science.gov (United States)
Douglas R. Rammer; Samuel L. Zelinka
2015-01-01
It has been well established that stainless steel nails have superior corrosion performance compared to carbon steel or galvanized nails in treated wood; however, their mechanical fastening behavior is unknown. In this paper, the performance of stainless steel nails is examined with respect to two important properties used in wood connection design: withdrawal strength...
4. Dependency Parsing
CERN Document Server
Kubler, Sandra; Nivre, Joakim
2009-01-01
Dependency-based methods for syntactic parsing have become increasingly popular in natural language processing in recent years. This book gives a thorough introduction to the methods that are most widely used today. After an introduction to dependency grammar and dependency parsing, followed by a formal characterization of the dependency parsing problem, the book surveys the three major classes of parsing models that are in current use: transition-based, graph-based, and grammar-based models. It continues with a chapter on evaluation and one on the comparison of different methods, and it close
5. Neutron source strength determination for on-line reactivity measurements
Energy Technology Data Exchange (ETDEWEB)
Hoogenboom, J.E.; Sluijs, A.R. van der
1988-01-01
A method is described to determine the effective neutron source strength in a nuclear reactor, which must be known when calculating the time-varying reactivity from inverse reactor kinetics for a reactor at low power. When for an initially subcritical reactor the reactivity is changed and kept constant after the change, the effective source strength can be determined from a linear regression of reactor power to a function proportional to the emission rate of delayed neutrons, which can be calculated from the reactor power history. In view of the relatively strong noise present in the reactor power signal at low power, a grouping method for the regression is preferred over the least-squares method. Experiments with a reactor simulator with known source strength showed good agreement. Application to actual reactor signals gave consistent and satisfactory results.
6. Strength of biodegradable polypropylene tapes filled with a modified starch
Science.gov (United States)
Vinidiktova, N. S.; Ermolovich, O. A.; Goldade, V. A.; Pinchuk, L. S.
2006-05-01
The possibility of creating composite materials with high deformation and strength characteristics based on polypropylene (PP) and a natural polysaccharide in the form of a modified starch (MS) has been studied. The modified starch is shown to interact chemically with functional groups of PP, thereby positively affecting the physicomechanical properties, structure, and water absorption properties of films and oriented flat fibers based on starch-filled PP. The strength characteristics of both oriented and unoriented composites are 1.5-2.0 times as high as those of the initial PP. The water absorption ability of the materials varies symbatically with content of MS, which points to the dominant contribution of interactions at the PP-MS interface. The introduction of MS into synthetic polymers offers a possibility of producing new ecologically safe materials with high strength characteristics.
7. Strength Properties of Aalborg Clay
DEFF Research Database (Denmark)
Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust
glacial time are characterised by the absence of this mussel. These deposits are named Aalborg Clay and Aalborg Sand. In the city of Aalborg, a fill layer superposes Aalborg Clay. This layer is at some places found to be 6m thick. This fill layer does not provide sufficient bearing capacity, which has...... resulted in many damaged buildings in Aalborg. To provide sufficient bearing capacity it is therefore necessary either to remove the fill or to construct the building on piles. Both methods imply that the strength of Aalborg Clay is important for the construction. This paper evaluates the strength...
8. Topological strength of magnetic skyrmions
Energy Technology Data Exchange (ETDEWEB)
Bazeia, D.; Ramos, J.G.G.S.; Rodrigues, E.I.B.
2017-02-01
This work deals with magnetic structures that attain integer and half-integer skyrmion numbers. We model and solve the problem analytically, and show how the solutions appear in materials that engender distinct, very specific physical properties, and use them to describe their topological features. In particular, we found a way to model skyrmion with a large transition region correlated with the presence of a two-peak skyrmion number density. Moreover, we run into the issue concerning the topological strength of a vortex-like structure and suggest an experimental realization, important to decide how to modify and measure the topological strength of the magnetic structure.
9. Modulating influences of memory strength and sensitivity of the retrieval test on the detectability of the sleep consolidation effect.
Science.gov (United States)
Schoch, Sarah F; Cordi, Maren J; Rasch, Björn
2017-11-01
Emotionality can increase recall probability of memories as emotional information is highly relevant for future adaptive behavior. It has been proposed that memory processes acting during sleep selectively promote the consolidation of emotional memories, so that neutral memories no longer profit from sleep consolidation after learning. This appears as a selective effect of sleep for emotional memories. However, other factors contribute to the appearance of a consolidation benefit and influence this interpretation. Here we show that the strength of the memory trace before sleep and the sensitivity of the retrieval test after sleep are critical factors contributing to the detection of the benefit of sleep on memory for emotional and neutral stimuli. 228 subjects learned emotional and neutral pictures and completed a free recall after a 12-h retention interval of either sleep or wakefulness. We manipulated memory strength by including an immediate retrieval test before the retention interval in half of the participants. In addition, we varied the sensitivity of the retrieval test by including an interference learning task before retrieval testing in half of the participants. We show that a "selective" benefit of sleep for emotional memories only occurs in the condition with high memory strength. Furthermore, this "selective" benefit disappeared when we controlled for the memory strength before the retention interval and used a highly sensitive retrieval test. Our results indicate that although sleep benefits are more robust for emotional memories, neutral memories similarly profit from sleep after learning when more sensitive indicators are used. We conclude that whether sleep benefits on memory appear depends on several factors, including emotion, memory strength and sensitivity of the retrieval test. Copyright © 2017 Elsevier Inc. All rights reserved.
10. Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
Directory of Open Access Journals (Sweden)
Kang Jie
2006-12-01
Full Text Available Abstract Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; below recommended levels (BL; 1.0 – 1.4 g·kg-1·day-1; n = 8, recommended levels (RL; 1.6 – 1.8 g·kg-1·day-1; n = 7 and above recommended levels (AL; > 2.0 g·kg-1·day-1; n = 8. Subjects were assessed for strength [one-repetition maximum (1-RM bench press and squat] and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, and insulin-like growth factor. No differences were seen in energy intake (3,171 ± 577 kcal between the groups, and the energy intake for all groups were also below the recommended levels for strength/power athletes. No significant changes were seen in body mass, lean body mass or fat mass in any group. Significant improvements in 1-RM bench press and 1-RM squat were seen in all three groups, however no differences between the groups were observed. Subjects in AL experienced a 22% and 42% greater change in Δ 1-RM squat and Δ 1-RM bench press than subjects in RL, however these differences were not significant. No significant changes were seen in any of the resting hormonal concentrations. The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements, or alterations in resting hormonal concentrations.
11. Time-varying market integration and expected returns in emerging mrkets
NARCIS (Netherlands)
de Jong, F.C.J.M.; de Roon, F.
2001-01-01
We use a simple model in which the expected returns in emerging markets depend on their systematicrisk as measured by their beta relative to the world portfolio as well as on the level ofintegration in that market. The level of integration is a time-varying variable that depends on themarket value
12. Identification of Time-Varying Pilot Control Behavior in Multi-Axis Control Tasks
Science.gov (United States)
Zaal, Peter M. T.; Sweet, Barbara T.
2012-01-01
Recent developments in fly-by-wire control architectures for rotorcraft have introduced new interest in the identification of time-varying pilot control behavior in multi-axis control tasks. In this paper a maximum likelihood estimation method is used to estimate the parameters of a pilot model with time-dependent sigmoid functions to characterize time-varying human control behavior. An experiment was performed by 9 general aviation pilots who had to perform a simultaneous roll and pitch control task with time-varying aircraft dynamics. In 8 different conditions, the axis containing the time-varying dynamics and the growth factor of the dynamics were varied, allowing for an analysis of the performance of the estimation method when estimating time-dependent parameter functions. In addition, a detailed analysis of pilots adaptation to the time-varying aircraft dynamics in both the roll and pitch axes could be performed. Pilot control behavior in both axes was significantly affected by the time-varying aircraft dynamics in roll and pitch, and by the growth factor. The main effect was found in the axis that contained the time-varying dynamics. However, pilot control behavior also changed over time in the axis not containing the time-varying aircraft dynamics. This indicates that some cross coupling exists in the perception and control processes between the roll and pitch axes.
13. Chairside CAD/CAM materials. Part 2: Flexural strength testing.
Science.gov (United States)
Wendler, Michael; Belli, Renan; Petschelt, Anselm; Mevec, Daniel; Harrer, Walter; Lube, Tanja; Danzer, Robert; Lohbauer, Ulrich
2017-01-01
14. Analysis on geometry-aware received signal strength based ...
African Journals Online (AJOL)
These handle different scenarios such as environment, adaptation, hybridization and the choice of context is dependent on user requirements. This paper present geometry-aware received signal strength (RSS) based positioning techniques where the influences of the geometries of the BSs (where location estimation ...
15. Decrease in back strength in asymmetric trunk postures
NARCIS (Netherlands)
Vink, P.; Daanen, H. A M; Meijst, W. J.; Ligteringen, J.
1992-01-01
The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry
16. Time varying behaviour of the loudspeaker suspension
DEFF Research Database (Denmark)
Agerkvist, Finn; Pedersen, Bo Rohde
2009-01-01
The compliance of the loudspeaker suspension is known to depend on the recent excitation level history. Previous investigations have shown that the electrical power as well as displacement and velocity plays a role. In this paper the hypothesis that the changes in compliance are caused mainly...... by how much the suspension has been stretched, i.e., the maximum displacement, is investigated. For this purpose the changes in compliance are measured when exposing the loudspeaker to different levels and types of electrical excitation signals, as well as mechanical excitation only. For sinusoidal...... excitation the change in compliance is shown to depend primarily on maximum displacement. But for square pulse excitation the duration of the excitation also plays an important role....
17. Time-Varying Periodicity in Intraday Volatility
DEFF Research Database (Denmark)
Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor
We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...
18. Flexible time-varying filter banks
Science.gov (United States)
Tuncer, Temel E.; Nguyen, Truong Q.
1993-09-01
Linear phase maximally flat FIR Butterworth filter approximations are discussed and a new filter design method is introduced. This variable cutoff filter design method uses the cosine modulated versions of a prototype filter. The design procedure is simple and different variants of this procedure can be used to obtain close to optimum linear phase filters. Using this method, flexible time-varying filter banks with good reconstruction error are introduced. These types of oversampled filter banks have small magnitude error which can be easily controlled by the appropriate choice of modulation frequency. This error can be further decreased by magnitude equalization without increasing the computational complexity considerably. Two dimensional design examples are also given.
19. Behavior of varying-alpha cosmologies
International Nuclear Information System (INIS)
Barrow, John D.; Sandvik, Haavard Bunes; Magueijo, Joao
2002-01-01
We determine the behavior of a time-varying fine structure 'constant' α(t) during the early and late phases of universes dominated by the kinetic energy of changing α(t), radiation, dust, curvature, and lambda, respectively. We show that after leaving an initial vacuum-dominated phase during which α increases, α remains constant in universes such as our own during the radiation era, and then increases slowly, proportional to a logarithm of cosmic time, during the dust era. If the universe becomes dominated by a negative curvature or a positive cosmological constant then α tends rapidly to a constant value. The effect of an early period of de Sitter or power-law inflation is to drive α to a constant value. Various cosmological consequences of these results are discussed with reference to recent observational studies of the value of α from quasar absorption spectra and to the existence of life in expanding universes
20. Emergence of epidemics in rapidly varying networks
International Nuclear Information System (INIS)
Kohar, Vivek; Sinha, Sudeshna
2013-01-01
We describe a simple model mimicking disease spreading on a network with dynamically varying connections, and investigate the dynamical consequences of switching links in the network. Our central observation is that the disease cycles get more synchronized, indicating the onset of epidemics, as the underlying network changes more rapidly. This behavior is found for periodically switched links, as well as links that switch randomly in time. We find that the influence of changing links is more pronounced in networks where the nodes have lower degree, and the disease cycle has a longer infective stage. Further, when the switching of links is periodic we observe finer dynamical features, such as beating patterns in the emergent oscillations and resonant enhancement of synchronization, arising from the interplay between the time-scales of the connectivity changes and that of the epidemic outbreaks
1. Spatially varying determinants of farmland conversion across Qiantang watershed, China.
Science.gov (United States)
Su, Shiliang; Xiao, Rui
2013-10-01
This paper employed geographically weighted regression (GWR) to characterize the determinants of farmland conversion at administrative scale between 1994 and 2003 across Qiantang watershed, China. Six determinants were identified: total area of forest, distance to highway, distance to second road, distance to river, population, and gross domestic product. Relationships between these identified determinants and farmland conversion showed great spatial non-stationarity, since their character, nature, and strength varied significantly across space. Typically, for cities whose development was heavily relied on road infrastructure development, the impacts of "distance to second road" and "distance to river" was negative. However, in mountainous areas, the restriction of terrain factors led to positive impacts from these two variables. For areas undergoing rapid socio-economic development, farmland conversion was accelerated by population growth and economic development. However, for more urbanized regions, a slow-down rate of farmland conversion would be expected. Our study highlighted that the problem of spatial non-stationarity should be addressed when qualifying the determinants of farmland conversion. Linking our results within the context of farmland protection, we argue that implementing local-specific land management practices, instead of the current one-size-fits-all framework, is the key for the success of farmland protection in China.
2. Time-varying multiplex network: Intralayer and interlayer synchronization
Science.gov (United States)
Rakshit, Sarbendu; Majhi, Soumen; Bera, Bidesh K.; Sinha, Sudeshna; Ghosh, Dibakar
2017-12-01
A large class of engineered and natural systems, ranging from transportation networks to neuronal networks, are best represented by multiplex network architectures, namely a network composed of two or more different layers where the mutual interaction in each layer may differ from other layers. Here we consider a multiplex network where the intralayer coupling interactions are switched stochastically with a characteristic frequency. We explore the intralayer and interlayer synchronization of such a time-varying multiplex network. We find that the analytically derived necessary condition for intralayer and interlayer synchronization, obtained by the master stability function approach, is in excellent agreement with our numerical results. Interestingly, we clearly find that the higher frequency of switching links in the layers enhances both intralayer and interlayer synchrony, yielding larger windows of synchronization. Further, we quantify the resilience of synchronous states against random perturbations, using a global stability measure based on the concept of basin stability, and this reveals that intralayer coupling strength is most crucial for determining both intralayer and interlayer synchrony. Lastly, we investigate the robustness of interlayer synchronization against a progressive demultiplexing of the multiplex structure, and we find that for rapid switching of intralayer links, the interlayer synchronization persists even when a large number of interlayer nodes are disconnected.
3. [Affective dependency].
Science.gov (United States)
Scantamburlo, G; Pitchot, W; Ansseau, M
2013-01-01
Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.
4. Strengths, Weaknesses, Opportunities and Threats
NARCIS (Netherlands)
Bull, J.W.; Jobstvogt, N.; Böhnke-Henrichs, A.; Mascarenhas, A.; Sitas, N.; Baulcomb, C.; Lambini, C.K.; Rawlins, M.; Baral, H.; Zähringer, J.; Carter-Silk, E.; Balzan, M.V.; Kenter, J.O.; Häyhä, T.; Petz, K.; Koss, R.
2016-01-01
The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an
5. Polynomial expansions and transition strengths
International Nuclear Information System (INIS)
Draayer, J.P.
1980-01-01
The subject is statistical spectroscopy applied to determining strengths and strength sums of excitation processes in nuclei. The focus will be on a ds-shell isoscalar E2 study with detailed shell-model results providing the standard for comparison; similar results are available for isovector E2 and M1 and E4 transitions as well as for single-particle transfer and ν +- decay. The present study is intended to serve as a tutorial for applications where shell-model calculations are not feasible. The problem is posed and a schematic theory for strengths and sums is presented. The theory is extended to include the effect of correlations between H, the system Hamiltonian, and theta, the excitation operator. Associated with correlation measures is a geometry that can be used to anticipate the goodness of a symmetry. This is illustrated for pseudo SU(3) in the fp-shell. Some conclusions about fluctuations and collectivity that one can deduce from the statistical results for strengths are presented
6. On strength of porous material
DEFF Research Database (Denmark)
Nielsen, Lauge Fuglsang
1999-01-01
The question of non-destructive testing of porous materials has always been of interest for the engineering profession. A number of empirically based MOE-MOR relations between stiffness (Modulus Of Elasticity) and strength (Modulus OF Rupture) of materials have been established in order to control...
7. Strengths, weaknesses, opportunities and threats
DEFF Research Database (Denmark)
Bull, Joseph William; Jobstvogt, N.; Böhnke-Henrichs, A.
2016-01-01
The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an assess...
8. Comparing strengths of beliefs explicitly
NARCIS (Netherlands)
Ghosh, S.; de Jongh, D.
2013-01-01
Inspired by a similar use in provability logic, formulas p > B q and p ≥ B q are introduced in the existing logical framework for discussing beliefs to express that the strength of belief in p is greater than (or equal to) that in q. Besides its usefulness in studying the properties of the concept
9. Strength training for the warfighter.
Science.gov (United States)
Kraemer, William J; Szivak, Tunde K
2012-07-01
Optimizing strength training for the warfighter is challenged by past training philosophies that no longer serve the modern warfighter facing the "anaerobic battlefield." Training approaches for integration of strength with other needed physical capabilities have been shown to require a periodization model that has the flexibility for changes and is able to adapt to ever-changing circumstances affecting the quality of workouts. Additionally, sequencing of workouts to limit over-reaching and development of overtraining syndromes that end in loss of duty time and injury are paramount to long-term success. Allowing adequate time for rest and recovery and recognizing the negative influences of extreme exercise programs and excessive endurance training will be vital in moving physical training programs into a more modern perspective as used by elite strength-power anaerobic athletes in sports today. Because the warfighter is an elite athlete, it is time that training approaches that are scientifically based are updated within the military to match the functional demands of modern warfare and are given greater credence and value at the command levels. A needs analysis, development of periodized training modules, and individualization of programs are needed to optimize the strength of the modern warfighter. We now have the knowledge, professional coaches and nonprofit organization certifications with continuing education units, and modern training technology to allow this to happen. Ultimately, it only takes command decisions and implementation to make this possible.
10. Modeling of Sylgard Adhesive Strength
Energy Technology Data Exchange (ETDEWEB)
Stevens, Ralph Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-02-03
Sylgard is the name of a silicone elastomeric potting material manufactured by Dow Corning Corporation.1 Although the manufacturer cites its low adhesive strength as a feature of this product, thin layers of Sylgard do in fact have a non-negligible strength, which has been measured in recent tensile and shear debonding tests. The adhesive strength of thin layers of Sylgard potting material can be important in applications in which components having signi cantly di erent thermal expansion properties are potted together, and the potted assembly is subjected to temperature changes. The tensile and shear tractions developed on the potted surfaces of the components can cause signi cant internal stresses, particularly for components made of low-strength materials with a high area-to-volume ratio. This report is organized as follows: recent Sylgard debonding tests are rst brie y summarized, with particular attention to the adhesion between Sylgard and PBX 9501, and also between Sylgard and aluminum. Next, the type of numerical model that will be used to simulate the debonding behavior exhibited in these tests is described. Then the calibration of the debonding model will be illustrated. Finally, the method by which the model parameters are adjusted (scaled) to be applicable to other, non- tested bond thicknesses is summarized, and all parameters of the model (scaled and unscaled) are presented so that other investigators can reproduce all of the simulations described in this report as well as simulations of the application of interest.
11. Creep rupture properties under varying load/temperature conditions on a nickel-base heat-resistant alloy strengthened by boron addition
International Nuclear Information System (INIS)
Tsuji, Hirokazu; Tanabe, Tatsuhiko; Nakajima, Hajime
1994-01-01
A series of constant load and temperature creep rupture tests and varying load and temperature creep rupture tests was carried out on Hastelloy XR whose boron content level is 60 mass ppm at 900 and 1000 C in order to examine the behavior of the alloy under varying load and temperature conditions. The life fraction rule completely fails in the prediction of the creep rupture life under varying load and temperature conditions though the rule shows good applicability for Hastelloy XR whose boron content level is below 10 mass ppm. The modified life fraction rule has been proposed based on the dependence of the creep rupture strength on the boron content level of the alloy. The modified rule successfully predicts the creep rupture life under the test conditions from 1000 to 900 C. The trend observed in the tests from 900 to 1000 C can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900 C plays the role of the protective barrier against the boron dissipation into the environment. (orig.)
12. Creep rupture properties under varying load/temperature conditions on a nickel-base heat-resistant alloy strengthened by boron addition
International Nuclear Information System (INIS)
Tsuji, Hirokazu; Nakajima, Hajime; Tanabe, Tatsuhiko.
1993-09-01
A series of constant load and temperature creep rupture tests and varying load and temperature creep rupture tests was carried out on Hastelloy XR whose boron content level is 60 mass ppm at 900 and 1000degC in order to examine the behavior of the alloy under varying load and temperature conditions. The life fraction rule completely fails in the prediction of the creep rupture life under varying load and temperature conditions though the rule shows good applicability for Hastelloy XR whose boron content level is below 10 mass ppm. The modified life fraction rule has been proposed based on the dependence of the creep rupture strength on the born content level of the alloy. The modified rule successfully predicts the creep rupture life under the test conditions from 1000degC to 900degC. The trend observed in the tests from 900degC to 1000degC can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900degC plays the role of the protective barrier against the boron dissipation into the environment. (author)
13. Velocity distribution of electrons in time-varying low-temperature plasmas: progress in theoretical procedures over the past 70 years
Science.gov (United States)
Makabe, Toshiaki
2018-03-01
A time-varying low-temperature plasma sustained by electrical powers with various kinds of fRequencies has played a key role in the historical development of new technologies, such as gas lasers, ozonizers, micro display panels, dry processing of materials, medical care, and so on, since World War II. Electrons in a time-modulated low-temperature plasma have a proper velocity spectrum, i.e. velocity distribution dependent on the microscopic quantum characteristics of the feed gas molecule and on the external field strength and the frequency. In order to solve and evaluate the time-varying velocity distribution, we have mostly two types of theoretical methods based on the classical and linear Boltzmann equations, namely, the expansion method using the orthogonal function and the procedure of non-expansional temporal evolution. Both methods have been developed discontinuously and progressively in synchronization with those technological developments. In this review, we will explore the historical development of the theoretical procedure to evaluate the electron velocity distribution in a time-varying low-temperature plasma over the past 70 years.
14. Crop yield response to climate change varies with cropping intensity.
Science.gov (United States)
Challinor, Andrew J; Parkes, Ben; Ramirez-Villegas, Julian
2015-04-01
Projections of the response of crop yield to climate change at different spatial scales are known to vary. However, understanding of the causes of systematic differences across scale is limited. Here, we hypothesize that heterogeneous cropping intensity is one source of scale dependency. Analysis of observed global data and regional crop modelling demonstrate that areas of high vs. low cropping intensity can have systematically different yields, in both observations and simulations. Analysis of global crop data suggests that heterogeneity in cropping intensity is a likely source of scale dependency for a number of crops across the globe. Further crop modelling and a meta-analysis of projected tropical maize yields are used to assess the implications for climate change assessments. The results show that scale dependency is a potential source of systematic bias. We conclude that spatially comprehensive assessments of climate impacts based on yield alone, without accounting for cropping intensity, are prone to systematic overestimation of climate impacts. The findings therefore suggest a need for greater attention to crop suitability and land use change when assessing the impacts of climate change. © 2015 John Wiley & Sons Ltd.
15. Effect of steam corrosion on HTGR core support post strength loss. Part II. Consequences of steam generator tube rupture event
International Nuclear Information System (INIS)
Wichner, R.P.
1977-01-01
To perform the assessment, a series of eight tube-rupture events of varying severity and probability were postulated. Case 1 pertains to the situation where the moisture detection, loop isolation, and dump procedures function as planned; the remaining seven cases suppose various defects in the moisture detection system, the core auxiliary coolant system, and the integrity of the prestressed concrete reactor vessel. Core post burnoffs beneath three typical fuel zones were estimated for each postulated event from the determined impurity compositions and core post temperature history. Two separate corrosion rate expressions were assumed, as deemed most appropriate of those published for the high-oxidant level typical in tube rupture events. It was found that the nominal core post beneath the highest power factor fuel zone would lose from 0.02 to 2.5 percent of their strength, depending on an assumed corrosion rate equation and the severity of the event. The effect of hot streaking during cooldown was determined by using preliminary estimates of its magnitude. It was found that localized strength loss beneath the highest power factor zone ranges from 0.23 to 12 percent, assuming reasonably probable hot-streaking circumstances. The combined worst case, hot streaking typical for a load-following transient and most severe accident sequence, yields an estimated strength loss of from 25 to 33 percent for localized regions beneath the highest power factor zones
16. Time Varying Behavior of the Loudspeaker Suspension
DEFF Research Database (Denmark)
Pedersen, Bo Rohde; Agerkvist, Finn T.
2007-01-01
The suspension part of the electrodynamic loudspeaker is often modelled as a simple linear spring with viscous damping, however the dynamic behaviour of the suspension is much more complicated than predicted by such a simple model. At higher levels the compliance becomes non-linear and often chan...... changes during excitation at high levels. This paper investigates how the compliance of the suspension depends on the excitation, i.e. level and frequency content. The measurements are compared with other known measurement methods of the suspension....
17. Response of Aphidius colemani to aphid sex pheromone varies depending on plant synergy and prior experience
OpenAIRE
Fernandez-Grandon, G. Mandela; Poppy, Guy M.
2015-01-01
A critical stage in the success of a parasitoid is the ability to locate a host within its habitat. It is hypothesized that a series of olfactory cues may be involved in altering the parasitoid's movement patterns at this stage of foraging. This paper focuses specifically on host habitat location and host location and the olfactory stimuli necessary to mediate the transition between these stages. Firstly, we confirm the ability of the parasitoid Aphidius colemani to detect the aphid sex phero...
18. Mortality-minimizing sandpipers vary stopover behavior dependent on age and geographic proximity to migrating predators
NARCIS (Netherlands)
Hope, D.D.; Lank, D.B.; Ydenberg, R.C.
2014-01-01
Ecological theory for long-distance avian migration considers time-, energy-, and mortality-minimizing tactics, but predictions about the latter have proven elusive. Migrants must make behavioral decisions that can favor either migratory speed or safety from predators, but often not both. We compare
19. Influence of postnatal glucocorticoids on hippocampal-dependent learning varies with elevation patterns and administration methods
Science.gov (United States)
2017-05-22
et al ., 1988 ; Bender et al ., 1991; Mrakotsky et al ., 2013), and there is evidence that effects can persist (Hitzert et al ., 2014; Lajic et al ...most frequently been observed in adults to correlate with changes in cognitive performance ( Gould et al ., 1999; Leuner et al ., 2006). As described... et al ., 1988 ) and Cavalieri methods (Gundersen et al ., 1988b) with
20. What you find depends on where you look: responses to proximate habitat vary with landscape context
Directory of Open Access Journals (Sweden)
Mary Ann Cunningham
2016-12-01
Full Text Available There is persistent interest in understanding responses of passerine birds to habitat fragmentation, but research findings have been inconsistent and sometimes contradictory in conclusions about how birds respond to characteristics of sites they occupy, such as habitat patch size or edge density. We examined whether these inconsistencies could result from differences in the amount of habitat in the surrounding landscape, e.g., for woodland birds, the amount of tree cover in the surrounding landscape. We compared responses of 22 woodland bird species to proximate-scale tree cover in open landscapes versus wooded landscapes. Our main expectation was that woodland birds would tolerate less suitable sites (less tree cover at the site scale in open environments where they had little choice-where little tree cover was available in the surrounding area. We compared responses using logistic regression coefficients and loess plots in open and wooded landscapes in eastern North Dakota, USA. Responses to proximate-scale tree cover were stronger, not weaker, as expected, in open landscapes. In some cases the sign of the response changed from positive to negative in contrasting landscapes. We draw two conclusions: First, observed responses to proximate habitat measures such as habitat extent or edge density cannot be interpreted reliably unless landscape context is specified. Second, birds appear more selective, not less so, where habitat is sparse. Habitat loss and fragmentation at the landscape scale are likely to reduce the usefulness of local habitat conservation, and regional drivers in land-use change can have important effects for site-scale habitat use.
1. Pleomorphic adenoma cells vary in their susceptibility to SV40 transformation depending on the initial karyotype.
Science.gov (United States)
Kazmierczak, B; Thode, B; Bartnitzke, S; Bullerdiek, J; Schloot, W
1992-07-01
Chromosomal aberrations involving 8q12 or 12q13-15 characterize two cytogenetic subgroups of salivary gland pleomorphic adenomas. As the tumors of the two groups differ in their clinical and histologic characteristics, we decided to determine their susceptibility to SV40 transformation. We transfected cell cultures from 13 adenomas with aberrations involving 8q12 and from seven adenomas with involvement of 12q13-15 using an SV40 plasmid coding for the early region of the viral genome. Whereas all cultures with aberrations of 12q13-15 showed transformed foci, only 4 of the 13 cultures with 8q12 abnormalities showed foci of transformed cells. We also observed a much higher immortalization rate in the first group (3/7 vs. 1/13). All successfully transformed tumor cell cultures showed a relatively stable karyotype in the pre-crisis stage and a high mitotic index, were T-antigen positive, and had an extended life span in vitro.
2. Wireless Concrete Strength Monitoring of Wind Turbine Foundations
Directory of Open Access Journals (Sweden)
Marcus Perry
2017-12-01
Full Text Available Wind turbine foundations are typically cast in place, leaving the concrete to mature under environmental conditions that vary in time and space. As a result, there is uncertainty around the concrete’s initial performance, and this can encourage both costly over-design and inaccurate prognoses of structural health. Here, we demonstrate the field application of a dense, wireless thermocouple network to monitor the strength development of an onshore, reinforced-concrete wind turbine foundation. Up-to-date methods in fly ash concrete strength and maturity modelling are used to estimate the distribution and evolution of foundation strength over 29 days of curing. Strength estimates are verified by core samples, extracted from the foundation base. In addition, an artificial neural network, trained using temperature data, is exploited to demonstrate that distributed concrete strengths can be estimated for foundations using only sparse thermocouple data. Our techniques provide a practical alternative to computational models, and could assist site operators in making more informed decisions about foundation design, construction, operation and maintenance.
3. Wireless Concrete Strength Monitoring of Wind Turbine Foundations.
Science.gov (United States)
Perry, Marcus; Fusiek, Grzegorz; Niewczas, Pawel; Rubert, Tim; McAlorum, Jack
2017-12-16
Wind turbine foundations are typically cast in place, leaving the concrete to mature under environmental conditions that vary in time and space. As a result, there is uncertainty around the concrete's initial performance, and this can encourage both costly over-design and inaccurate prognoses of structural health. Here, we demonstrate the field application of a dense, wireless thermocouple network to monitor the strength development of an onshore, reinforced-concrete wind turbine foundation. Up-to-date methods in fly ash concrete strength and maturity modelling are used to estimate the distribution and evolution of foundation strength over 29 days of curing. Strength estimates are verified by core samples, extracted from the foundation base. In addition, an artificial neural network, trained using temperature data, is exploited to demonstrate that distributed concrete strengths can be estimated for foundations using only sparse thermocouple data. Our techniques provide a practical alternative to computational models, and could assist site operators in making more informed decisions about foundation design, construction, operation and maintenance.
4. [Caffeine dependence].
Science.gov (United States)
Ogawa, Naoshi; Ueki, Hirofumi
2010-08-01
Caffeine is the most widely consumed psychoactive substance in the world and is a legal stimulant that is readily available to children. The potential for dependence on caffeine has been debated. Presently, due to a paucity of clinical evidence on caffeine dependence, no such diagnosis is included in the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision (DSM-IV-TR). Although in recent studies, a subset of the general population was found to demonstrate caffeine dependence. It is valuable for psychiatrists and primary care physicians to recognize caffeine dependence as a clinical syndrome, since some people are distressed by their caffeine use and feel they can not control or stop their problematic use.
5. Strength degradation of oxidized graphite support column in VHTR
International Nuclear Information System (INIS)
Park, Byung Ha; No, Hee Cheon
2010-01-01
Air-ingress events caused by large pipe breaks are important accidents considered in the design of Very High Temperature Gas-Cooled Reactors (VHTRs). A main safety concern for this type of event is the possibility of core collapse following the failure of the graphite support column, which can be oxidized by ingressed air. In this study, the main target is to predict the strength of the oxidized graphite support column. Through compression tests for fresh and oxidized graphite columns, the compressive strength of IG-110 was obtained. The buckling strength of the IG-110 column is expressed using the following empirical straight-line formula: σ cr,buckling =91.34-1.01(L/r). Graphite oxidation in Zone 1 is volume reaction and that in Zone 3 is surface reaction. We notice that the ultimate strength of the graphite column oxidized in Zones 1 and 3 only depends on the slenderness ratio and bulk density. Its strength degradation oxidized in Zone 1 is expressed in the following nondimensional form: σ/σ 0 =exp(-kd), k=0.114. We found that the strength degradation of a graphite column, oxidized in Zone 3, follows the above buckling empirical formula as the slenderness of the column changes. (author)
6. Kinetics of strength gain of biocidal cements
Directory of Open Access Journals (Sweden)
Rodin Aleksandr Ivanovich
Full Text Available Biocorrosion becomes the determinative durability factor of buildings and constructions. Damages of construction materials caused by bacteria, filamentous fungi, actinomycetes constitute a serious danger to the constructions of a building or a structure and to the health of people. Biodeteriorations are typical both in old and new constructions. A great quantity of destruction factors of industrial and residential buildings under the influence of microorganisms was established in practice. Providing products and constructions based on concretes fungicidal and bactericidal properties is an important direction of modern construction material science. The most efficient way to solve this task is creation of biocidal cements. The article presents the results of experimental studies of kinetic dependences of strength gain by biocidal cements by physico-mechanical and physico-chemical analysis methods. The identical velocity character of initial hydration of the developed compositions of biocidal cements is set, as well as a more calm behavior of hardening processes at later terms. It has been established that the compositions of biocidal cements modified by sodium sulfate and sodium fluoride possess the greatest strength.
7. Microsatellites in varied arenas of research
Directory of Open Access Journals (Sweden)
K S Remya
2010-01-01
Full Text Available Microsatellites known as simple-sequence repeats (SSRs or short-tandem repeats (STRs, represent specific sequences of DNA consisting of tandemly repeated units of one to six nucleotides. The repetitive nature of microsatellites makes them particularly prone to grow or shrink in length and these changes can have both good and bad consequences for the organisms that possess them. They are responsible for various neurological diseases and hence the same cause is now utilized for the early detection of various diseases, such as, Schizophrenia and Bipolar Disorder, Congenital generalized Hypertrichosis, Asthma, and Bronchial Hyperresponsiveness. These agents are widely used for forensic identification and relatedness testing, and are predominant genetic markers in this area of application. The application of microsatellites is an extending web and covers the varied scenarios of science, such as, conservation biology, plant genetics, and population studies. At present, researches are progressing round the globe to extend the use of these genetic repeaters to unmask the hidden genetic secrets behind the creation of the world.
8. Stratospheric Impact of Varying Sea Surface Temperatures
Science.gov (United States)
Newman, Paul A.; Nash, Eric R.; Nielsen, Jon E.; Waugh, Darryn; Pawson, Steven
2004-01-01
The Finite-Volume General Circulation Model (FVGCM) has been run in 50 year simulations with the: 1) 1949-1999 Hadley Centre sea surface temperatures (SST), and 2) a fixed annual cycle of SSTs. In this presentation we first show that the 1949-1999 FVGCM simulation produces a very credible stratosphere in comparison to an NCEP/NCAR reanalysis climatology. In particular, the northern hemisphere has numerous major and minor stratospheric warming, while the southern hemisphere has only a few over the 50-year simulation. During the northern hemisphere winter, temperatures are both warmer in the lower stratosphere and the polar vortex is weaker than is found in the mid-winter southern hemisphere. Mean temperature differences in the lower stratosphere are shown to be small (less than 2 K), and planetary wave forcing is found to be very consistent with the climatology. We then will show the differences between our varying SST simulation and the fixed SST simulation in both the dynamics and in two parameterized trace gases (ozone and methane). In general, differences are found to be small, with subtle changes in planetary wave forcing that lead to reduced temperatures in the SH and increased temperatures in the NH.
9. TIME-VARYING DYNAMICAL STAR FORMATION RATE
Energy Technology Data Exchange (ETDEWEB)
Lee, Eve J.; Chang, Philip; Murray, Norman, E-mail: [email protected] [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada)
2015-02-10
We present numerical evidence of dynamic star formation in which the accreted stellar mass grows superlinearly with time, roughly as t {sup 2}. We perform simulations of star formation in self-gravitating hydrodynamic and magnetohydrodynamic turbulence that is continuously driven. By turning the self-gravity of the gas in the simulations on or off, we demonstrate that self-gravity is the dominant physical effect setting the mass accretion rate at early times before feedback effects take over, contrary to theories of turbulence-regulated star formation. We find that gravitational collapse steepens the density profile around stars, generating the power-law tail on what is otherwise a lognormal density probability distribution function. Furthermore, we find turbulent velocity profiles to flatten inside collapsing regions, altering the size-line width relation. This local flattening reflects enhancements of turbulent velocity on small scales, as verified by changes to the velocity power spectra. Our results indicate that gas self-gravity dynamically alters both density and velocity structures in clouds, giving rise to a time-varying star formation rate. We find that a substantial fraction of the gas that forms stars arrives via low-density flows, as opposed to accreting through high-density filaments.
10. А new factor effecting gel strength of pectin polysaccharides
Directory of Open Access Journals (Sweden)
S. E. Kholov
2016-01-01
Full Text Available Pectin polysaccharides obtained from various raw materials have a different component composition and form gels with water, sugar and acid or calcium. In this study, an experimental approach the gelation properties of different pectin samples, varied from different sources, using new methods of hydrolysis and purification. Samples were obtained by hydrolysis of accelerated extraction of pectin and purified by diaultrfiltration, have a high gel strength. The highest gel strength have been found in series of high methoxyl (HM- pectin samples of apple, peach, orange and low methoxyl (LM- pectin samples of commercial citrus pectin and apple pectin obtained by new method. It is shown that in addition to the basic parameters (the content of galacturonic acid, degree of esterification, molecular weight and hidrodinamic radius macromolecule to affect gel strength pectins aggregation of macromolecules, which is determined by the z-average molecular weight. There were observed a clear pattern of the influence of the molecular weight on hydrodynamic parameters for both HM- and LM- pectin samples on the gel strength. It were shown that a high values of molecular weight, intrinsic viscosity, and radius of gyration of pectin samples can significantly increase gel strength, while the value of Mz oppositely influenced the gel strength. As a result, a systematic analysis of this parameter and its relationship to the average molecular weight found that indeed the ratio Mz/Mw for pectin’s is an crucial to assess the quality of pectin at the study of gel strength for pectin polysaccharides.
11. Effects of plyometric training volume and training surface on explosive strength.
Science.gov (United States)
Ramírez-Campillo, Rodrigo; Andrade, David C; Izquierdo, Mikel
2013-10-01
The purpose of this study is to examine the effects of different volume and training surfaces during a short-term plyometric training program on neuromuscular performance. Twenty-nine subjects were randomly assigned to 4 groups: control group (CG, n = 5), moderate volume group (MVG, n = 9, 780 jumps), moderate volume hard surface group (MVGHS, n = 8, 780 jumps), and high volume group (HVG, n = 7, 1,560 jumps). A series of tests were performed by the subjects before and after 7 weeks of plyometric training. These tests were measurement of maximum strength (5 maximum repetitions [5RMs]), drop jumps (DJs) of varying heights (20, 40, and 60 cm), squat and countermovement jumps (SJ and CMJ, respectively), timed 20-m sprint, agility, body weight, and height. The results of the present study suggest that high training volume leads to a significant increase in explosive performance that requires fast stretch-shortening cycle (SSC) actions (such as DJ and sprint) in comparison to what is observed after a moderate training volume regimen. Second, when plyometric training is performed on a hard training surface (high-impact reaction force), a moderate training volume induces optimal stimulus to increase explosive performance requiring fast SSC actions (e.g., DJ), maximal dynamic strength enhancement, and higher training efficiency. Thus, a finding of interest in the study was that after 7 weeks of plyometric training, performance enhancement in maximal strength and in actions requiring fast SSC (such as DJ and sprint) were dependent on the volume of training and the surface on which it was performed. This must be taken into account when using plyometric training on different surfaces.
12. Overview of Effect of Game Means on Dynamics of Strength Development in Junior Girls
Directory of Open Access Journals (Sweden)
Т. Ю. Нікітенкова
2017-03-01
13. Systematics of strength function sum rules
Directory of Open Access Journals (Sweden)
Calvin W. Johnson
2015-11-01
Full Text Available Sum rules provide useful insights into transition strength functions and are often expressed as expectation values of an operator. In this letter I demonstrate that non-energy-weighted transition sum rules have strong secular dependences on the energy of the initial state. Such non-trivial systematics have consequences: the simplification suggested by the generalized Brink–Axel hypothesis, for example, does not hold for most cases, though it weakly holds in at least some cases for electric dipole transitions. Furthermore, I show the systematics can be understood through spectral distribution theory, calculated via traces of operators and of products of operators. Seen through this lens, violation of the generalized Brink–Axel hypothesis is unsurprising: one expects sum rules to evolve with excitation energy. Furthermore, to lowest order the slope of the secular evolution can be traced to a component of the Hamiltonian being positive (repulsive or negative (attractive.
14. Epidemic spreading in time-varying community networks
Energy Technology Data Exchange (ETDEWEB)
Ren, Guangming, E-mail: [email protected], E-mail: [email protected] [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: [email protected], E-mail: [email protected] [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)
2014-06-15
The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q > q{sub c} and die when q < q{sub c}. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.
15. Conditional CAPM: Time-varying Betas in the Brazilian Market
Directory of Open Access Journals (Sweden)
Frances Fischberg Blank
2014-10-01
Full Text Available The conditional CAPM is characterized by time-varying market beta. Based on state-space models approach, beta behavior can be modeled as a stochastic process dependent on conditioning variables related to business cycle and estimated using Kalman filter. This paper studies alternative models for portfolios sorted by size and book-to-market ratio in the Brazilian stock market and compares their adjustment to data. Asset pricing tests based on time-series and cross-sectional approaches are also implemented. A random walk process combined with conditioning variables is the preferred model, reducing pricing errors compared to unconditional CAPM, but the errors are still significant. Cross-sectional test show that book-to-market ratio becomes less relevant, but past returns still capture cross-section variation
16. Superheated emulsions in neutron spectrometry by varying ambient pressure
International Nuclear Information System (INIS)
Das, Mala; Sawamura, Teruko
2005-01-01
The principle of present work lies on the dependence of the threshold neutron energy on the dimensionless quantity ''degree of metastability (ss)'' of superheated liquids. The response of the superheated emulsions consists of the drops of superheated liquid (C 2 Cl 2 F 4 , b.p. 3.77 deg. C) has been measured at different 'ss' by varying ambient pressure at different temperatures, in the presence of neutrons generated in Pb by a (γ,n) reaction from 45 MeV electron LINAC of Hokkaido University. To unfold the neutron energy spectrum, a relationship has been developed between the 'ss' of superheated liquids and the threshold neutron energy. The spectrum at the detector position has been calculated by the MCNP code and a comparison has been made with the experimental spectrum. The utilisation of 'ss' is more flexible as this relation can be applied to both positive and negative ambient pressures as well as at different ambient temperatures
17. Epidemic spreading in time-varying community networks
International Nuclear Information System (INIS)
Ren, Guangming; Wang, Xingyuan
2014-01-01
The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q c . The epidemic will survive when q > q c and die when q c . These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure
18. Influência de variáveis do treinamento contra-resistência sobre a força muscular de idosos: uma revisão sistemática com ênfase nas relações dose-resposta Influencia de las variables de entrenamiento contra-resistencia sobre la fuerza muscular de ancianos: una revisión sistemática con énfasis en las relaciones dosis-respuesta Influence of counter-resistance training variables on elderly muscular strength: a systematic review with emphasis on dose/response relationships
Directory of Open Access Journals (Sweden)
Nádia Lima da Silva
2007-02-01
19. The Effect Of Weave Construction On Tear Strength Of Woven Fabrics
Directory of Open Access Journals (Sweden)
Eryuruk Selin Hanife
2015-09-01
Full Text Available The tear strength of a woven fabric is very important, since it is more closely related to serviceability of the fabric. Tearing strength of the fabrics depend on the mobility of the yarn within the fabric structure. In this study, the tearing strength of four types of fabrics warp rib, weft rib, ripstop and plain weave were analysed, which were produced in different densities and with filament and texturised polyester yarns.
20. Cyclic fatigue of a high-strength corrosion-resistant sheet TRIP steel
Science.gov (United States)
Terent'ev, V. F.; Alekseeva, L. E.; Korableva, S. A.; Prosvirnin, D. V.; Pankova, M. N.; Filippov, G. A.
2014-04-01
The mechanical properties of 0.3- and 0.8-mm-thick high-strength corrosion-resistant TRIP steel having various levels of strength properties are studied during static and cyclic loading in the high-cycle fatigue range. The fatigue fracture surface is analyzed by fractography, and the obtained results demonstrate ductile and quasi-brittle fracture mechanisms of this steel depending on the strength properties of the steel and the content of deformation martensite in it.
1. Tolerable Time-Varying Overflow on Grass-Covered Slopes
Directory of Open Access Journals (Sweden)
Steven A. Hughes
2015-03-01
Full Text Available Engineers require estimates of tolerable overtopping limits for grass-covered levees, dikes, and embankments that might experience steady overflow. Realistic tolerance estimates can be used for both resilient design and risk assessment. A simple framework is developed for estimating tolerable overtopping on grass-covered slopes caused by slowly-varying (in time overtopping discharge (e.g., events like storm surges or river flood waves. The framework adapts the well-known Hewlett curves of tolerable limiting velocity as a function of overflow duration. It has been hypothesized that the form of the Hewlett curves suggests that the grass erosion process is governed by the flow work on the slope above a critical threshold velocity (referred to as excess work, and the tolerable erosional limit is reached when the cumulative excess work exceeds a given value determined from the time-dependent Hewlett curves. The cumulative excess work is expressed in terms of overflow discharge above a critical discharge that slowly varies in time, similar to a discharge hydrograph. The methodology is easily applied using forecast storm surge hydrographs at specific locations where wave action is minimal. For preliminary planning purposes, when storm surge hydrographs are unavailable, hypothetical equations for the water level and overflow discharge hydrographs are proposed in terms of the values at maximum overflow and the total duration of overflow. An example application is given to illustrate use of the methodology.
2. Muscle Strength and Poststroke Hemiplegia
DEFF Research Database (Denmark)
Kristensen, Otto H; Stenager, Egon; Dalgas, Ulrik
2017-01-01
undergone peer review; and (4) were available in English or Danish. DATA EXTRACTION: The psychometric properties of isokinetic dynamometry were reviewed with respect to reliability, validity, and responsiveness. Furthermore, comparisons of strength between paretic, nonparetic, and comparable healthy muscles...... isokinetic dynamometry. DATA SOURCES: A systematic literature search of 7 databases was performed. STUDY SELECTION: Included studies (1) enrolled participants with definite poststroke hemiplegia according to defined criteria; (2) assessed muscle strength or power by criterion isokinetic dynamometry; (3) had...... were reviewed. DATA SYNTHESIS: Twenty studies covering 316 PPSH were included. High intraclass correlation coefficient (ICC) inter- and intrasession reliability was reported for isokinetic dynamometry, which was independent of the tested muscle group, contraction mode, and contraction velocity...
3. Electric quadrupole strength in nuclei
International Nuclear Information System (INIS)
Kirson, M.W.
1979-01-01
Isoscalar electric quadrupole strength distributions in nuclei are surveyed, and it is concluded that the strength is shared, in most cases, roughly equally between low-lying transitions and the giant quadrupole state. The same is not true of the isovector case. A simple extension of the schematic model gives a remarkably successul description of the data, and emphasizes the vital importance of the coupling between high-lying and low-lying quadrupole modes. The standadrd simple representation of the giant quadrupole resonance as produced by operating on the nuclear ground state with the quadrupole transition operator is not applicable to the isoscalar case. It is suggested that giant resonances fall into broad classes of similar states, with considerable qualitative differences between the distinct classes. (author)
4. Line strengths in WN stars
International Nuclear Information System (INIS)
Leep, E.M.
1982-01-01
The author has analyzed high-dispersion spectra of over 100 WN stars in the Galaxy and the Large Magellenic Cloud (LMC). Most of the spectra were obtained through 4-m telescopes (Conti, Leep, and Perry 1981). The measured strengths of the WN classification lines N III lambdalambda4634-41, N IV lambda4057, N V lambda4604 (Smith 1968) for stars on WN subtypes 2.5-8 are shown. The assignments of WN subtypes are based on visual estimates of ratios of line strengths according to the scheme of Smith (1968), except that stars appearing to be earlier than WN3 are classified as WN2 or WN2.5 as explained by van der Hucht et al. (1981) and by Conti, Leep and Perry (1981). (Auth.)
5. It's material strength, not a negative Grueneisen gamma
International Nuclear Information System (INIS)
Sinz, K.H.P.H.; Moss, W.C.
1993-01-01
Hydrocode simulations of CORRTEX data (shock position as a function of time) require a model for the material properties of the medium in which the explosion occurs. Prior to the BULLION underground nuclear test, Furnish performed gun experiments on core samples that were taken from a satellite hole near the working point. We have analyzed some of these data and constructed a constitutive model that is consistent with the gun data. The model consists of a Mie-Grueneisen equation of state that is parameterized using a Hugoniot, a Grueneisen gamma that is only volume dependent, and a pressure dependent strength model. Previous analyses of these particular experiments have ignored material strength, because of its lack of influence on numerical simulations of the CORRTEX data. However, if strength is excluded, negative gammas are required to fit Furnish's data, but these negative gammas give an extremely poor fit to the CORRTEX field data. Our simple model, which includes strength, has a positive volume dependent gamma. The model fits Furnish's laboratory data and the measured experimental CORRTEX data. What is remarkable about the model is that all of the parameters in it can be obtained from the gun data, indicating that laboratory experiments of this type (and perhaps others) on core samples are potentially more useful than believed previously
6. It's material strength, not a negative Grueneisen gamma
International Nuclear Information System (INIS)
Sinz, K.H.P.H.; Moss, W.C.
1993-02-01
Hydrocode simulations of CORRTEX data (shock position as a function of time) require a model for the material properties of the medium in which the explosion occurs. Prior to the BULLION underground nuclear test, Furnish performed gun experiments on core samples that were taken from a satellite hole near the working point. The authors have analyzed some of these data and constructed a constitutive model that is consistent with the gun data. The model consists of a Mie-Grueneisen equation of state that is parameterized using the Hugoniot, a Grueneisen gamma that is only volume dependent, and a pressure dependent strength model. Previous analyses of these particular experiments have ignored material strength, because of its lack of influence on numerical simulations of the CORRTEX data. However, if strength is excluded, negative gammas are required to fit Furnish's data, but these negative gammas give an extremely poor fit to the CORRTEX field data. The simple model, which includes strength, has a positive volume dependent gamma. The model fits Furnish's laboratory data and the measured experimental CORRTEX data. What is remarkable about the model is that all of the parameters in it can be obtained from the gun data, indicating that laboratory experiments of this type (and perhaps others) on core samples are potentially more useful than believed previously
7. Fatigue strength degradation of metals in corrosive environments
Science.gov (United States)
Adasooriya, N. D.; Hemmingsen, T.; Pavlou, D.
2017-12-01
Structures exposed to aggressive environmental conditions are often subjected to time-dependent loss of coating and loss of material due to corrosion; this causes reduction in the cross-sectional properties of the members, increased surface roughness, surface irregularities and corrosion pits, and degradation of material strengths. These effects have been identified and simulated in different research studies. However, time and corrosive media dependent fatigue strength curves for materials have not been discussed in the design or assessment guidelines for structures. This paper attempts to review the corrosion degradation process and available approaches/models used to determine the fatigue strength of corroded materials and to interpolate corrosion deterioration data. High cycle fatigue and full range fatigue life formulae for fatigue strength of corroded materials are proposed. The above formulae depend on the endurance limit of corroded material, in addition to the stress-life fatigue curve parameters of the uncorroded material. The endurance limit of corroded material can either be determined by a limited number of tests in the very high-cycle fatigue region or predicted by an analytical approach. Comparison with experimentally measured corrosion fatigue behavior of several materials is provided and discussed.
8. Soil strength and forest operations
OpenAIRE
Beekman, F.
1987-01-01
The use of heavy machinery and transport vehicles is an integral part of modern forest operations. This use often causes damage to the standing trees and to the soil. In this study the effects of vehicle traffic on the soil are analysed and the possible consequences for forest management discussed. The study is largely restricted to sandy and loamy soils because of their importance for Dutch forestry.
Soil strength, defined as the resistance of soil structure against the impa...
9. Strength and Microstructure of Ceramics
Science.gov (United States)
1989-11-01
Forex - one particular alumina ceramic, I our own detailed crack ample, the relatively large values of r, and c* for the VI observations, and those of...particularly toughness indices, 1i71", indicating that there is sonic the c° , T parameters. However, the indentation mcth- kind of trade -o1Tbetwecn...macroscopic and microsnpic odology takes us closer to the strengths of specimens toughness levels, and that this trade -off is cont’olled by with natural
10. Long range supergravity coupling strengths
International Nuclear Information System (INIS)
Kenyon, I.R.
1991-01-01
A limit of 2x10 -13 has recently been deduced for the fractional difference between the gravitational masses of the K 0 and anti K 0 mesons. This limit is applied here to put stringent limits on the strengths of the long range vector-scalar gravitational couplings envisaged in supergravity theories. A weaker limit is inferred from the general relativistic fit to the precession of the orbit of the pulsar PSR1913+16. (orig.)
11. Ultrahigh-strength submicron-sized metallic glass wires
International Nuclear Information System (INIS)
Wang, Y.B.; Lee, C.C.; Yi, J.; An, X.H.; Pan, M.X.; Xie, K.Y.; Liao, X.Z.; Cairney, J.M.; Ringer, S.P.; Wang, W.H.
2014-01-01
In situ deformation experiments were performed in a transmission electron microscope to investigate the mechanical properties of submicron-sized Pd 40 Cu 30 Ni 10 P 20 metallic glass (MG) wires. Results show that the submicron-sized MG wires exhibit intrinsic ultrahigh tensile strength of ∼2.8 GPa, which is nearly twice as high as that in their bulk counterpart, and ∼5% elastic strain approaching the elastic limits. The tensile strength, engineering strain at failure and deformation mode of the submicron-sized MG wires depend on the diameter of the wires
12. Emergence of synchronization and regularity in firing patterns in time-varying neural hypernetworks
Science.gov (United States)
Rakshit, Sarbendu; Bera, Bidesh K.; Ghosh, Dibakar; Sinha, Sudeshna
2018-05-01
We study synchronization of dynamical systems coupled in time-varying network architectures, composed of two or more network topologies, corresponding to different interaction schemes. As a representative example of this class of time-varying hypernetworks, we consider coupled Hindmarsh-Rose neurons, involving two distinct types of networks, mimicking interactions that occur through the electrical gap junctions and the chemical synapses. Specifically, we consider the connections corresponding to the electrical gap junctions to form a small-world network, while the chemical synaptic interactions form a unidirectional random network. Further, all the connections in the hypernetwork are allowed to change in time, modeling a more realistic neurobiological scenario. We model this time variation by rewiring the links stochastically with a characteristic rewiring frequency f . We find that the coupling strength necessary to achieve complete neuronal synchrony is lower when the links are switched rapidly. Further, the average time required to reach the synchronized state decreases as synaptic coupling strength and/or rewiring frequency increases. To quantify the local stability of complete synchronous state we use the Master Stability Function approach, and for global stability we employ the concept of basin stability. The analytically derived necessary condition for synchrony is in excellent agreement with numerical results. Further we investigate the resilience of the synchronous states with respect to increasing network size, and we find that synchrony can be maintained up to larger network sizes by increasing either synaptic strength or rewiring frequency. Last, we find that time-varying links not only promote complete synchronization, but also have the capacity to change the local dynamics of each single neuron. Specifically, in a window of rewiring frequency and synaptic coupling strength, we observe that the spiking behavior becomes more regular.
13. Path Dependence
DEFF Research Database (Denmark)
Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...
14. Achievable Strength-Based Signal Detection in Quantity-Constrained PAM OOK Concentration-Encoded Molecular Communication.
Science.gov (United States)
2016-10-01
In this paper, the expressions of achievable strength-based detection probabilities of concentration-encoded molecular communication (CEMC) system have been derived based on finite pulsewidth (FP) pulse-amplitude modulated (PAM) on-off keying (OOK) modulation scheme and strength threshold. An FP-PAM system is characterized by its duty cycle α that indicates the fraction of the entire symbol duration the transmitter remains on and transmits the signal. Results show that the detection performance of an FP-PAM OOK CEMC system significantly depends on the statistical distribution parameters of diffusion-based propagation noise and intersymbol interference (ISI). Analytical detection performance of an FP-PAM OOK CEMC system under ISI scenario has been explained and compared based on receiver operating characteristics (ROC) for impulse (i.e., spike)-modulated (IM) and FP-PAM CEMC schemes. It is shown that the effects of diffusion noise and ISI on ROC can be explained separately based on their communication range-dependent statistics. With full duty cycle, an FP-PAM scheme provides significantly worse performance than an IM scheme. The paper also analyzes the performance of the system when duty cycle, transmission data rate, and quantity of molecules vary.
15. Creep strength and rupture ductility of creep strength enhanced ferritic steels
Energy Technology Data Exchange (ETDEWEB)
Kushima, Hideaki; Sawada, Kota; Kimura, Kazuhiro [National Inst. for Materials Science, Tsukuba, Ibaraki (Japan)
2010-07-01
Creep strength and rupture ductility of Creep Strength Enhanced Ferritic (CSEF) steels were investigated from a viewpoint of stress dependence in comparison with conventional low alloy ferritic creep resistant steels. Inflection of stress vs. time to rupture curve was observed at 50% of 0.2% offset yield stress for both CSEF and conventional ferritic steels. Creep rupture ductility tends to decrease with increase in creep exposure time, however, those of conventional low alloy steels indicate increase in the long-term. Creep rupture ductility of the ASME Grades 92 and 122 steels indicates drastic decrease with decrease in stress at 50% of 0.2% offset yield stress. Stress dependence of creep rupture ductility of the ASME Grades 92 and 122 steels is well described by stress ratio to 0.2% offset yield stress, regardless of temperature. Drop of creep rupture ductility is caused by inhomogeneous recovery at the vicinity of prior austenite grain boundary, and remarkable drop of creep rupture ductility of CSEF steels should be derived from those stabilized microstructure. (orig.)
16. Modelling suction instabilities in soils at varying degrees of saturation
Directory of Open Access Journals (Sweden)
Buscarnera Giuseppe
2016-01-01
Full Text Available Wetting paths imparted by the natural environment and/or human activities affect the state of soils in the near-surface, promoting transitions across different regimes of saturation. This paper discusses a set of techniques aimed at quantifying the role of hydrologic processes on the hydro-mechanical stability of soil specimens subjected to saturation events. Emphasis is given to the mechanical conditions leading to coupled flow/deformation instabilities. For this purpose, energy balance arguments for three-phase systems are used to derive second-order work expressions applicable to various regimes of saturation. Controllability analyses are then performed to relate such work input with constitutive singularities that reflect the loss of strength under coupled and/or uncoupled hydro-mechanical forcing. A suction-dependent plastic model is finally used to track the evolution of stability conditions in samples subjected to wetting, thus quantifying the growth of the potential for coupled failure modes upon increasing degree of saturation. These findings are eventually linked with the properties of the field equations that govern pore pressure transients, thus disclosing a conceptual link between the onset of coupled hydro-mechanical failures and the evolution of suction with time. Such results point out that mathematical instabilities caused by a non-linear suction dependent behaviour play an important role in the advanced constitutive and/or numerical tools that are commonly used for the analysis of geomechanical problems in the unsaturated zone, and further stress that the relation between suction transients and soil deformations is a key factor for the interpretation of runaway failures caused by intense saturation events.
17. Analysis and design of composite slab by varying different parameters
Science.gov (United States)
Lambe, Kedar; Siddh, Sharda
2018-03-01
Composite deck slabs are in demand because of its faster, lighter and economical construction work. Composite slab consists of cold formed deck profiled sheet and concrete either lightweight or normal. Investigation of shear behaviour of the composite slab is very complex. Shear bond strength depends on the various parameter such as a shape of sheeting, a thickness of the sheet, type of embossment and its frequency of use, shear stiffener or intermediate stiffener, type of load, an arrangement of load, length of shear span, the thickness of concrete and support friction etc. In present study finite element analysis is carried out with ABAQUS 6.13, a simply supported composite slab is considered for the investigation of the shear bond behaviour of the composite slab by considering variation in three different parameters, the shape of a sheet, thickness of sheet and shear span. Different shear spans of two different shape of cold formed deck profiled sheet i.e. with intermediate stiffeners and without intermediate stiffeners are considered with two different thicknesses (0.8 mm and 1.2 mm) for simulation. In present work, simulation of models has done for static loading with 20 mm mesh size is considered.
18. Resistive transition in disordered superconductors with varying intergrain coupling
International Nuclear Information System (INIS)
Ponta, L; Carbone, A; Gilli, M
2011-01-01
The effect of disorder is investigated in granular superconductive materials with strong- and weak-links. The transition is controlled by the interplay of the tunneling g and intragrain g intr conductances, which depend on the strength of the intergrain coupling. For g intr , the transition first involves the grain boundary, while for g ∼ g intr the transition occurs into the whole grain. The different intergrain couplings are considered by modeling the superconducting material as a disordered network of Josephson junctions. Numerical simulations show that on increasing the disorder, the resistive transition occurs for lower temperatures and the curve broadens. These features are enhanced in disordered superconductors with strong-links. The different behavior is further checked by estimating the average network resistance for weak- and strong-links in the framework of the effective medium approximation theory. These results may shed light on long standing puzzles such as: (i) enhancement of the superconducting transition temperature of many metals in the granular states; (ii) suppression of superconductivity in homogeneously disordered films compared to standard granular systems close to the metal-insulator transition; (iii) enhanced degradation of superconductivity by doping and impurities in strongly linked materials, such as magnesium diboride, compared to weakly linked superconductors, such as cuprates.
19. Comparison of creep behavior under varying load/temperature conditions between Hastelloy XR alloys with different boron content levels
International Nuclear Information System (INIS)
Tsuji, Hirokazu; Nakajima, Hajime; Shindo, Masami; Tanabe, Tatsuhiko; Nakasone, Yuji.
1996-01-01
In the design of the high-temperature components, it is often required to predict the creep rupture life under the conditions in which the stress and/or temperature may vary by using the data obtained with the constant load and temperature creep rupture tests. Some conventional creep damage rules have been proposed to meet the above-mentioned requirement. Currently only limited data are available on the behavior of Hastelloy XR, which is a developed alloy as the structural material for high-temperature components of the High-Temperature Engineering Test Reactor (HTTR), under varying stress and/or temperature creep conditions. Hence a series of constant load and temperature creep rupture tests as well as varying load and temperature creep rupture tests was carried out on two kinds of Hastelloy XR alloys whose boron content levels are different, i.e., below 10 and 60 mass ppm. The life fraction rule completely fails in the prediction of the creep rupture life of Hastelloy XR with 60 mass ppm boron under varying load and temperature conditions though the rule shows good applicability for Hastelloy XR with below 10 mass ppm boron. The change of boron content level of the material during the tests is the most probable source of impairing the applicability of the life fraction rule to Hastelloy XR whose boron content level is 60 mass ppm. The modified life fraction rule has been proposed based on the dependence of the creep rupture strength on the boron content level of the alloy. The modified rule successfully predicts the creep rupture life under the two stage creep test conditions from 1000 to 900degC. The trend observed in the two stage creep tests from 900 to 1000degC can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900degC plays the role of the protective barrier against the boron dissipation into the environment. (J.P.N.)
20. Age-varying associations between non-marital sexual behavior and depressive symptoms across adolescence and young adulthood
Science.gov (United States)
Vasilenko, Sara A.
2016-01-01
1. IIW guidelines on weld quality in relationship to fatigue strength
CERN Document Server
Jonsson, Bertil; Hobbacher, A F; Kassner, M; Marquis, G
2016-01-01
This book presents guidelines on quantitative and qualitative measures of the geometric features and imperfections of welds to ensure that it meets the fatigue strength requirements laid out in the recommendations of the IIW (International Institute of Welding). Welds that satisfy these quality criteria can be assessed in accordance with existing IIW recommendations based on nominal stress, structural stress, notch stress or linear fracture mechanics. Further, the book defines more restrictive acceptance criteria based on weld geometry features and imperfections with increased fatigue strength. Fatigue strength for these welds is defined as S-N curves expressed in terms of nominal applied stress or hot spot stress. Where appropriate, reference is made to existing quality systems for welds.In addition to the acceptance criteria and fatigue assessment curves, the book also provides guidance on their inspection and quality control. The successful implementation of these methods depends on adequate training for o...
2. Influence of strength training intensity on subsequent recovery in elderly
DEFF Research Database (Denmark)
da Rosa Orssatto, Lucas Bet; de Moura, Bruno Monteiro; de Souza Bezerra, Ewertton
2018-01-01
Understanding the influence of strength training intensity on subsequent recovery in elderly is important to avoid reductions in physical function during the days following training. Twenty-two elderly were randomized in two groups: G70 (65.9 ± 4.8 years, n = 11) and G95 (66.9 ± 5.1, n = 11...... in elderly depending on the type of physical function and intensity of training. Higher intensity resulted in greater impairment. Exercise prescription in elderly should take this into account, e.g., by gradually increasing intensity during the first months of strength training. These results have relevance...... for elderly who have to be fit for work or other activities in the days following strength training....
3. The relationship between compressive strength and flexural strength of pavement geopolymer grouting material
Science.gov (United States)
Zhang, L.; Han, X. X.; Ge, J.; Wang, C. H.
2018-01-01
To determine the relationship between compressive strength and flexural strength of pavement geopolymer grouting material, 20 groups of geopolymer grouting materials were prepared, the compressive strength and flexural strength were determined by mechanical properties test. On the basis of excluding the abnormal values through boxplot, the results show that, the compressive strength test results were normal, but there were two mild outliers in 7days flexural strength test. The compressive strength and flexural strength were linearly fitted by SPSS, six regression models were obtained by linear fitting of compressive strength and flexural strength. The linear relationship between compressive strength and flexural strength can be better expressed by the cubic curve model, and the correlation coefficient was 0.842.
4. Investigations on the tensile strength of high performance concrete incorporating silica fume
International Nuclear Information System (INIS)
Santanu Bhanja; Bratish Sengupta
2005-01-01
Though the literature is rich in reporting on silica fume concrete the technical data on tensile strength is quite limited. The present paper is directed towards developing a better understanding on the isolated contribution of silica fume on the tensile strengths of High Performance Concrete. Extensive experimentation was carried out over water-binder ratios ranging from 0.26 to 0.42 and silica fume binder ratios from 0.0 to 0.3. For all the mixes compressive, flexural and split tensile strengths were determined at 28 days. The results of the present investigation indicate that silica fume incorporation results in significant improvements in the tensile strengths of concrete. It is also observed that the optimum replacement percentage, which led to maximization of strength, is not a constant one but depends on the water- cementitious material ratio of the mix. Compared to split tensile strengths, flexural strengths have exhibited greater percentage gains in strength. Increase in split tensile strength beyond 15% silica fume replacement is almost insignificant whereas sizeable gains in flexural tensile strength have occurred even up to 25% replacements. For the present investigation transgranular failure of concrete was observed which indicate that silica fume incorporation results in significant improvements in the strength of both paste and transition zone. (authors)
5. Patient safety climate strength: a concept that requires more attention
Science.gov (United States)
Ginsburg, Liane; Gilin Oore, Debra
2016-01-01
Background When patient safety climate (PSC) surveys are used in healthcare, reporting typically focuses on PSC level (mean or per cent positive scores). This paper explores how an additional focus on PSC strength can enhance the utility of PSC survey data. Setting and participants 442 care providers from 24 emergency departments (EDs) across Canada. Methods We use anonymised data from the Can-PSCS PSC instrument collected in 2011 as part of the Qmentum accreditation programme. We examine differences in climate strength across EDs using the Rwg(j) and intraclass correlation coefficients measures of inter-rater agreement. Results Across the six survey dimensions, median Rwg(j) was sufficiently high to support shared climate perceptions (0.64–0.83), but varied widely across the 24 ED units. We provide an illustrative example showing vastly different climate strength (Rwg(j) range=0.17–0.86) for units with an equivalent level of PSC (eg, climate mean score=3). Conclusions Most PSC survey results focus solely on climate level. To facilitate improvement in PSC, we advocate a simple, holistic safety climate profile including three metrics: climate level (using mean or per cent positive climate scores), climate strength (using the Rwg(j), or SD as a proxy) and the shape of the distribution (using histograms to see the distribution of scores within units). In PSC research, we advocate paying attention to climate strength as an important variable in its own right. Focusing on PSC level and strength can further understanding of the extent to which PSC is a key variable in the domain of patient safety. PMID:26453636
6. Strength of mortar containing rubber tire particle
Science.gov (United States)
Jusoh, M. A.; Abdullah, S. R.; Adnan, S. H.
2018-04-01
The main focus in this investigation is to determine the strength consist compressive and tensile strength of mortar containing rubber tire particle. In fact, from the previous study, the strength of mortar containing waste rubber tire in mortar has a slightly decreases compare to normal mortar. In this study, rubber tire particle was replacing on volume of fine aggregate with 6%. 9% and 12%. The sample were indicated M0 (0%), M6 (6%), M9 (9%) and M12 (12%). In this study, two different size of sample used with cube 100mm x 100mm x 100mm for compressive strength and 40mm x 40mm x 160mm for flexural strength. Morphology test was conducted by using Scanning electron microscopic (SEM) were done after testing compressive strength test. The concrete sample were cured for day 3, 7 and 28 before testing. Results compressive strength and flexural strength of rubber mortar shown improved compare to normal mortar.
7. optimizing compressive strength characteristics of hollow building
African Journals Online (AJOL)
eobe
Keywords: hollow building Blocks, granite dust, sand, partial replacement, compressive strength. 1. INTRODUCTION ... exposed to extreme climate. The physical ... Sridharan et al [13] conducted shear strength studies on soil-quarry dust.
8. Elastic buckling strength of corroded steel plates
structural safety assessment of corroded structures, residual strength should be ... Rahbar-Ranji (2001) has proposed a spectrum for random simulation of ... The main aim of the present work is to investigate the buckling strength of simply ...
9. Safety of strength training in premenopausal women: musculoskeletal injuries from a two-year randomized trial.
Science.gov (United States)
Warren, Meghan; Schmitz, Kathryn H
2009-01-01
The health benefits of strength training must be weighed against risks, including injuries. A prior study observed 4.2 injuries that limited usual activities for a day per 1000 strength training sessions among men and women. The analysis herein explores the incidence rates of musculoskeletal injuries from strength training in women. Randomized controlled trial. SETTING; Free-living community. A total of 163 injury-free, overweight, sedentary, premenopausal women aged 25 to 44 years. Two years of strength training (n = 81) or standard care (n = 82). The intervention followed published guidelines (U.S. Department of Health and Human Services) with hypothesized injury prevention strategies. An injury survey was administered at years 1 and 2. Injury was defined as physical activity or strength training associated injuries that limited daily activities for 1 week or more. Denominators for rate calculation were accelerometer-measured physical activity and strength training attendance (strength training only). The between-group probability of injuries was assessed using generalized estimating equations. Injury incidence rates were higher in strength training compared with standard care. In strength training, the injury rates were 3.6 per 1000 strength training sessions (95% confidence interval: 2.5-4.8 per 1000) for physical activity-related injuries, and 2.6 per 1000 (95% confidence interval: 1.5-3.6 per 1000) for strength training-related injuries. Injury rates varied by definition and denominator. Strength training had lower injury rates than previously reported, providing preliminary support for the prevention strategies. The finding of strength training injuries underscores the need for balancing the benefits against the potential risks of this exercise modality.
10. Statistical characterization of tensile strengths for a nuclear-type core graphite
International Nuclear Information System (INIS)
Kennedy, C.R.; Eatherly, W.P.
1986-09-01
A data set of tensile strengths comprising over 1200 experimental points has been analyzed statistically in conformance with the observed phenomenon of background and disparate flaws. The data are consistent with a bimodal normal distribution. If corrections are made for strength dependence on density, the background mode is Weibull. It is proposed the disparate mode can be represented by a combination of binomial and order statistics. The resultant bimodal model would show a strong dependence on stress volume
11. Influence of refraction index strength on the light propagation in dielectrics material with periodic refraction index
International Nuclear Information System (INIS)
Hidayat, Arif; Latifah, Eny; Kurniati, Diana; Wisodo, Hari
2016-01-01
This study investigated the influence of refraction index strength on the light propagation in refraction index-varied dielectric material. This dielectric material served as photonic lattice. The behavior of light propagation influenced by variation of refraction index in photonic lattice was investigated. Modes of the guiding light were determined numerically using squared-operator iteration method. It was found that the greater the strength of refraction index, the smaller the guiding modes.
12. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength
Science.gov (United States)
Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.
13. Microstructural origins of yield-strength changes in AISI 316 during fission or fusion irradiation
International Nuclear Information System (INIS)
Garner, F.A.; Hamilton, M.L.; Panayotou, N.F.; Johnson, G.D.
1981-08-01
The changes in yield strength of AISI 316 irradiated in breeder reactors have been successfully modeled in terms of concurrent changes in microstructural components. Two new insights involving the strength contributions of voids and Frank loops have been incorporated into the hardening models. Both the radiation-induced microstructure and the yield strength exhibit transients which are then followed by saturation at a level dependent on the irradiation temperature. Extrapolation to anticipated fusion behavior based on microstructural comparisons leads to the conclusion that the primary influence of transmutational differences is only to alter the transient behavior and not the saturation level of yield strength
14. Astrocytes regulate heterogeneity of presynaptic strengths in hippocampal networks
Science.gov (United States)
Letellier, Mathieu; Park, Yun Kyung; Chater, Thomas E.; Chipman, Peter H.; Gautam, Sunita Ghimire; Oshima-Takago, Tomoko; Goda, Yukiko
2016-01-01
Dendrites are neuronal structures specialized for receiving and processing information through their many synaptic inputs. How input strengths are modified across dendrites in ways that are crucial for synaptic integration and plasticity remains unclear. We examined in single hippocampal neurons the mechanism of heterosynaptic interactions and the heterogeneity of synaptic strengths of pyramidal cell inputs. Heterosynaptic presynaptic plasticity that counterbalances input strengths requires N-methyl-d-aspartate receptors (NMDARs) and astrocytes. Importantly, this mechanism is shared with the mechanism for maintaining highly heterogeneous basal presynaptic strengths, which requires astrocyte Ca2+ signaling involving NMDAR activation, astrocyte membrane depolarization, and L-type Ca2+ channels. Intracellular infusion of NMDARs or Ca2+-channel blockers into astrocytes, conditionally ablating the GluN1 NMDAR subunit, or optogenetically hyperpolarizing astrocytes with archaerhodopsin promotes homogenization of convergent presynaptic inputs. Our findings support the presence of an astrocyte-dependent cellular mechanism that enhances the heterogeneity of presynaptic strengths of convergent connections, which may help boost the computational power of dendrites. PMID:27118849
Energy Technology Data Exchange (ETDEWEB)
Kim, Donghyun; Kim, Hyochan; Yang, Yongsik; In, Wangkee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Haksung [Hanyang University, Seoul (Korea, Republic of)
2016-10-15
16. Noisy time-dependent spectra
International Nuclear Information System (INIS)
Shore, B.W.; Eberly, J.H.
1983-01-01
The definition of a time-dependent spectrum registered by an idealized spectrometer responding to a time-varying electromagnetic field as proposed by Eberly and Wodkiewicz and subsequently applied to the spectrum of laser-induced fluorescence by Eberly, Kunasz, and Wodkiewicz is here extended to allow a stochastically fluctuating (interruption model) environment: we provide an algorithm for numerical determination of the time-dependent fluorescence spectrum of an atom subject to excitation by an intense noisy laser and interruptive relaxation
17. Temperature and Pressure Dependence of Signal Amplitudes for Electrostriction Laser-Induced Thermal Acoustics
Science.gov (United States)
Herring, Gregory C.
2015-01-01
The relative signal strength of electrostriction-only (no thermal grating) laser-induced thermal acoustics (LITA) in gas-phase air is reported as a function of temperature T and pressure P. Measurements were made in the free stream of a variable Mach number supersonic wind tunnel, where T and P are varied simultaneously as Mach number is varied. Using optical heterodyning, the measured signal amplitude (related to the optical reflectivity of the acoustic grating) was averaged for each of 11 flow conditions and compared to the expected theoretical dependence of a pure-electrostriction LITA process, where the signal is proportional to the square root of [P*P /( T*T*T)].
18. Effect of blasting on the strength of a rock mass
Energy Technology Data Exchange (ETDEWEB)
Muller, L
1964-01-01
Although the fact that blasting concussions tend to loosen a rock mass has always been known, the enormous reduction in strength associated with such loosening is not generally recognized. Recent investigations of the effect of blasting on a rock mass have shown that even slight loosening may markedly reduce the strength. This factor introduces a new slant on modern blasting methods, some of which will have to be considered more critically. The sensitivity of the mass to impacts depends on stress concentrations at the end of joints (Kerbspannungen) and on tensile stresses developed in the immediate vicinity of a joint, even in regions where the field stresses are not tensile. Thus, the sensitivity depends on the shape and orientation of the joints and particularly on the degree of separation of the individual joint families. The orientation of the joint families to the strains produced by blasting is just as important as the reduction in overall strength arising from the drop in friction due to the effects of the ''knocking out'' process (Foppl) on the joint body complex. Concussions may critically increase the degree of separation of the joint network thus reducing the tensile and shear strengths of the rock mass. (19 refs.)
19. Effect of blasting on the strength of a rock mass
Energy Technology Data Exchange (ETDEWEB)
Muller, L.
1964-01-01
Although the fact that blasting concussions tend to loosen a rock mass has always been known, the enormous reduction in strength associated with such loosening is not generally recognized. Recent investigations of the effect of blasting on a rock mass have shown that even slight loosening may markedly reduce the strength. This factor introduces a new slant on modern blasting methods, some of which will have to be considered more critically. The sensitivity of the mass to impacts depends on stress concentrations at the end of joints (Kerbspannungen) and on tensile stresses developed in the immediate vicinity of a joint, even in regions where the field stresses are not tensile. Thus, the sensitivity depends on the shape and orientation of the joints and particularly on the degree of separation of the individual joint families. The orientation of the joint families to the strains produced by blasting is just as important as the reduction in overall strength arising from the drop in friction due to the effects of the ''knocking out'' process (Foppl) on the joint body complex. Concussions may critically increase the degree of separation of the joint network thus reducing the tensile and shear strengths of the rock mass. (19 refs.)
20. Strengths and Satisfaction across the Adult Lifespan
Science.gov (United States)
Isaacowitz, Derek M.; Vaillant, George E.; Seligman, Martin E. P.
2003-01-01
Positive psychology has recently developed a classification of human strengths (Peterson & Seligman, in press). We aimed to evaluate these strengths by investigating the strengths and life satisfaction in three adult samples recruited from the community (young adult, middle-aged, and older adult), as well as in the surviving men of the Grant study…
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https://puzzling.stackexchange.com/questions/110604/an-altered-list
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# An Altered List
The following list of items has been altered. They all use some form of wordplay originating from the item, with some being very literal and straightforward, while others are obscure and challenging. You need not solve all of the items (but congrats if you do!), the answer is the category of the original items. Good luck!
• ">->o"
• A hose
• A test question
• Art
• The NFL (if everyone wore red helmets)
• Dirt on a hand?
• A political TV show filmed at Charles University
• 0.0697564737
• Two "Sonic the Hedgehog" characters
• .- / -... .- -. -..
• Harry, Hermione, & Ron
• A typical LEGO minifigure head
This is a list of:
stories by Arthur Conan Doyle featuring his detective, Sherlock Holmes.
The clues should be interpreted as follows:
">->o"
Possibly The Adventure of the Crooked Man, since the symbols form the shape of a man lying down. (Alternatively, he may be Creeping instead, since the quotation marks might suggest movement lines...)
A hose
The Adventure of the Empty House - since if we 'empty' the word HOUSE by removing its middle letter, we get HOSE!
A test question
The Adventure of the Missing Three-Quarter (sounds like a question in a mathematics test)
Art
Possibly The Adventure of the Retired Colourman, since a 'colourman' is an art supply dealer.
The NFL (if everyone wore red helmets)
The Red-Headed League (the 'L' in NFL stands for 'League')
Dirt on a hand?
The Adventure of the Engineer's Thumb (which would potentially be covered in grease)
(The OP reveals in comments that their intention was actually The Adventure of the Second Stain, which might sound like the second hand of a clock is dirty...)
A political TV show filmed at Charles University
A Scandal in Bohemia (Charles University is found in the historic region of Bohemia in modern-day Czechia)
0.0697564737
The Sign of the Four - this number is $$sin(4)$$ i.e. the 'sine of 4'.
Two "Sonic the Hedgehog" characters
.- / -... .- -. -..
The Adventure of the Speckled Band - the Morse code decoded spells 'A BAND'.
Harry, Hermione, & Ron
The Adventure of the Three Students (Harry Potter, Hermione Granger and Ron Weasley are all students together at Hogwarts in the books by J.K. Rowling)
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https://docs.galpy.org/en/v1.7.2/reference/potentialnfw.html
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# NFW potential¶
class galpy.potential.NFWPotential(amp=1.0, a=1.0, normalize=False, rmax=None, vmax=None, conc=None, mvir=None, vo=None, ro=None, H=70.0, Om=0.3, overdens=200.0, wrtcrit=False)[source]
Class that implements the NFW potential
$\rho(r) = \frac{\mathrm{amp}}{4\,\pi\,a^3}\,\frac{1}{(r/a)\,(1+r/a)^{2}}$
__init__(amp=1.0, a=1.0, normalize=False, rmax=None, vmax=None, conc=None, mvir=None, vo=None, ro=None, H=70.0, Om=0.3, overdens=200.0, wrtcrit=False)[source]
NAME:
__init__
PURPOSE:
Initialize a NFW potential
INPUT:
amp - amplitude to be applied to the potential (default: 1); can be a Quantity with units of mass or Gxmass
a - scale radius (can be Quantity)
normalize - if True, normalize such that vc(1.,0.)=1., or, if given as a number, such that the force is this fraction of the force necessary to make vc(1.,0.)=1.
Alternatively, NFW potentials can be initialized in the following two manners:
1. rmax= radius where the rotation curve peaks (can be a Quantity, otherwise assumed to be in internal units)
vmax= maximum circular velocity (can be a Quantity, otherwise assumed to be in internal units)
2. conc= concentration
mvir= virial mass in 10^12 Msolar
in which case you also need to supply the following keywords
H= (default: 70) Hubble constant in km/s/Mpc
Om= (default: 0.3) Omega matter
overdens= (200) overdensity which defines the virial radius
wrtcrit= (False) if True, the overdensity is wrt the critical density rather than the mean matter density
ro=, vo= distance and velocity scales for translation into internal units (default from configuration file)
OUTPUT:
(none)
HISTORY:
2010-07-09 - Written - Bovy (NYU)
2014-04-03 - Initialization w/ concentration and mass - Bovy (IAS)
2020-04-29 - Initialization w/ rmax and vmax - Bovy (UofT)
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https://quantumcomputing.stackexchange.com/questions/10050/how-can-i-see-without-math-the-action-of-a-gate-in-matrix-form/10055
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# How can I see, without math, the action of a gate in matrix form?
Suppose we have the Fredkin gate with
$$F= \left( {\begin{array}{cc} 1 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 1 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 1 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 1 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 0 & 0 & 1 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 \\ \end{array} } \right)$$
But how is it possible to "see" what its action is without making any matrix multiplication?
In this document, on solving 4.25, they claim that the action of $$F$$ is, in the computational basis, $$F|0,y,z\rangle=|0,y,z\rangle$$ and $$F|1,y,z\rangle=|1,z,y\rangle$$. But how is it possible to know this beforehand? I feel that I am missing this mental "gymnastic" that I feel is crucial for developing algorithms.
Besides the already given answers note that there is indeed some "mental gymnastics" involved here. As soon as you're getting more acquainted with quantum computing, you know some of your usual gates, including the $$\mathsf{SWAP}$$ gate that appears in your question: \begin{align} \mathsf{SWAP} = \begin{bmatrix} 1 &0 &0 &0 \\ 0 &0 &1 &0 \\ 0 &1 &0 &0 \\ 0 &0 &0 &1 \\ \end{bmatrix} \end{align}
Now, how do we see that the Fredkin gate corresponds to a controlled $$\mathsf{SWAP}$$ gate? Looking closer at the Fredkin gate shows us that it has a block structure where the upper left block is an identity matrix and the lower right block is the $$\mathsf{SWAP}$$ gate: \begin{align} \mathsf{Fredkin} = \mathsf{CSWAP} = \begin{bmatrix} \mathbb{I} & 0 \\ 0 & \mathsf{SWAP} \end{bmatrix} \end{align}
And this structure is in fact general! All gates that are controlled on the first qubit have this block structure. Consider for example the well known $$\mathsf{CNOT}$$ gate \begin{align} \mathsf{CNOT} = \begin{bmatrix} 1 &0 &0 &0 \\ 0 &1 &0 &0 \\ 0 &0 &0 &1 \\ 0 &0 &1 &0 \\ \end{bmatrix}= \begin{bmatrix} \mathbb{I} & 0 \\ 0 & X \end{bmatrix} \end{align} which is an identity matrix on the upper left (hence the $$\mathsf{C}$$ in $$\mathsf{CNOT}$$) and a Pauli $$\mathsf{X}$$ gate -- which is the quantum $$\mathsf{NOT}$$ gate -- on the lower right.
So why is this the case? As pointed our by DaftWullie, we assume that the basis vectors in our Hilbert space correspond in ascending order to our basis states, i.e. \begin{align} 000, 001, 010, 011, 100, 101, 110, 111 \end{align} for three qubits. If we want to perform an arbitrary unitary $$\mathsf{U}$$ on the second and third qubit controlled by the first qubit, the corresponding matrix must act trivially (i.e. as identity matrix) on the first 4 basis vectors, just because for them the control bit is $$0$$. On the last 4 basis vectors, the control bit is $$1$$ and the operation $$U$$ is thus performed on these basis vectors. As the control bit must not change under the whole operation, the basis states starting with $$0$$ and the basis states starting with $$1$$ can not mix, yielding the overall matrix structure \begin{align} \mathsf{CU} = \begin{bmatrix} \mathbb{I} & 0 \\ 0 & \mathsf{U} \end{bmatrix} \end{align}
• I think you accidentally wrote a 0 instead of a 1 in the CNOT matrix. – user253751 Mar 2 '20 at 13:39
• Thanks for pointing that out! – Johannes Jakob Meyer Mar 2 '20 at 14:23
For a 0/1 matrix, the sort of protocol that I use is to write out the basis in the standard order. For three qubits, this is: 000,001,010,011,100,101,110,111 (the numbers 0 to 7 written in order in binary). You can list these next to the rows and the columns. Now, a given 1 entry in the matrix has a specific row and column (and there is only one of these for each row and column). The matrix acts to transform the column label into the row label.
So, for example, the first 4 elements $$0xy$$ all transform into themselves (because that part of the matrix is identity). Whereas 110 (penultimate column) transforms into 101, the 6th row.
We care about $$F$$'s action on the basis states, where basis states are represented by
$$$$\begin{pmatrix} 1\\0\\0\\0\\0\\0\\0\\0 \end{pmatrix}, \begin{pmatrix} 0\\1\\0\\0\\0\\0\\0\\0 \end{pmatrix}, \ldots, \begin{pmatrix} 0\\0\\0\\0\\0\\0\\0\\1 \end{pmatrix}$$$$
It should be fairly easy to see that on most basis states, this gate will act as the identity. The only exceptions are $$(0,0,0,0,0,1,0,0)^T$$ and $$(0,0,0,0,0,0,1,0)^T$$, which get swapped.
States of the form $$|0yz\rangle$$ are those with a one in one of the first four rows. Clearly these don't get swapped.
States of form $$|1yz\rangle$$ have a one in one of the last four rows. Look how they get mapped:
\begin{align} |1yz\rangle :=|100\rangle &\mapsto |100\rangle = |1zy\rangle\\ |1yz\rangle :=|101\rangle &\mapsto |110\rangle = |1zy\rangle\\ |1yz\rangle :=|110\rangle &\mapsto |101\rangle = |1zy\rangle\\ |1yz\rangle :=|111\rangle &\mapsto |111\rangle = |1zy\rangle\\ \end{align}
as desired. What might be tripping you up is the fact that mapping $$|100\rangle$$ to $$|100\rangle$$ (and similarly for $$|111\rangle$$) can technically be thought of as swapping the last two bits.
What's the intuition? This gate is very close to being diagonal. It's easy to see the action of a diagonal matrix on a vector (especially a vector with only one nonzero entry, i.e. computational basis states), so my first instinct was to look at that action, and then assess where it deviates from diagonality and try to figure out what that deviation actually does.
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https://sti.bmj.com/highwire/markup/150470/expansion?width=1000&height=500&iframe=true&postprocessors=highwire_tables%2Chighwire_reclass%2Chighwire_figures%2Chighwire_math%2Chighwire_inline_linked_media%2Chighwire_embed
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Table 2
Prediction rule for quantifying the probability of C trachomatis infection
PredictorScore
WomenMen
*Women, (post)coital bleeding previous 4 weeks; men, frequent urination previous 4 weeks.
An estimate of the probability of C trachomatis infection can be calculated using the formula p(Ct) = 1/1+exp (– LPS), where LPS = −7.26+0.47×score.
Age group (years)
15–1911
20–2400
25–2900
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http://mathhelpforum.com/calculus/54508-stationary-points-local-points-extrema.html
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# Math Help - Stationary Points, Local points of Extrema
1. ## Stationary Points, Local points of Extrema
What are some methods I can find roots to these types of function.
By simplifying with parathesis. Or there are easy methods? Advise apprciate
$-32x^3+12x$
2. Originally Posted by skyslimit
What are some methods I can find roots to these types of function.
By simplifying with parathesis. Or there are easy methods? Advise apprciate
$-32x^3+12x$
$-4x(8x^2-3)=0$
$-4x=0$
$8x^2-3=0$
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http://ctessayfnsn.paycheckadvance.us/the-main-structural-difference-between-starch.html
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# The main structural difference between starch
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## The main structural difference between starch
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The main structural difference between starch
Rated 3/5 based on 27 review
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http://www.numdam.org/item/?id=ITA_2011__45_2_235_0
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Normalization of edit sequences for text synchronization
RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 45 (2011) no. 2, pp. 235-248.
It often occurs that local copies of a text are modified by users but that the local modifications are not synchronized (thus allowing the merged text to become the source for later editions) until later when, for instance the network connection is reestablished. Since text editions usually affect a small fraction of the whole content, the history of edit operations provides a compact representation of the modified file. In this paper, we define a normal form for these records which will permit for the comparison of all text files that have been obtained by editing a common source S when the difference between each output file Oi and the source file is given as a sequence Li of edit operations. We show that the normalized sequence is unique for all the equivalent text editions and provide efficient procedures with which to compute this normal form and to obtain the edit sequence LM transforming S into a merged file M which integrates all the local modifications. We also discuss how these normalization can be integrated into the operational transformation paradigm for optimistic replication.
DOI : https://doi.org/10.1051/ita/2011017
Classification : 68U99
Mots clés : edit distance, text synchronization, reconciliation of replicas
@article{ITA_2011__45_2_235_0,
author = {Carrasco, Rafael C. and S\'anchez D\'\i az, Alexander},
title = {Normalization of edit sequences for text synchronization},
journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
pages = {235--248},
publisher = {EDP-Sciences},
volume = {45},
number = {2},
year = {2011},
doi = {10.1051/ita/2011017},
zbl = {1218.68193},
mrnumber = {2811656},
language = {en},
url = {http://www.numdam.org/item/ITA_2011__45_2_235_0/}
}
Carrasco, Rafael C.; Sánchez Díaz, Alexander. Normalization of edit sequences for text synchronization. RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 45 (2011) no. 2, pp. 235-248. doi : 10.1051/ita/2011017. http://www.numdam.org/item/ITA_2011__45_2_235_0/
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https://lucamariot.org/publication/mpjl-gecco-2017/
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# Evolutionary algorithms for the design of orthogonal Latin squares based on cellular automata
### Abstract
We investigate the design of Orthogonal Latin Squares (OLS) by means of Genetic Algorithms (GA) and Genetic Programming (GP). Since we focus on Latin squares generated by Cellular Automata (CA), the problem can be reduced to the search of pairs of Boolean functions that give rise to OLS when used as CA local rules. As it is already known how to design CA-based OLS with linear Boolean functions, we adopt the evolutionary approach to address the nonlinear case, experimenting with different encodings for the candidate solutions. In particular, for GA we consider single bitstring, double bitstring and quaternary string encodings, while for GP we adopt a double tree representation. We test the two metaheuristics on the spaces of local rules pairs with $n = 7$ and $n = 8$ variables, using two fitness functions. The results show that GP is always able to generate OLS, even if the optimal solutions found with the first fitness function are mostly linear. On the other hand, GA achieves a remarkably lower success rate than GP in evolving OLS, but the corresponding Boolean functions are always nonlinear.
Publication
Proceedings of the Genetic and Evolutionary Computation Conference, GECCO 2017, Berlin, Germany, July 15-19, 2017
Date
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|
https://justrocketscience.com/post/r_parallel_jsonl/
|
JSON is becoming more and more widely used in data lakes, especially as a replacement for CSV. In particular, JSONLines where one JSON object is stored per line is to be mentioned here. Although the format has some disadvantages (i.e., overhead, supports only few data types), the advantages mostly outweigh them. For example, the individual lines are easier to read by humans and the format is much more standardized. In addition, each line has its own JSON object that can be processed independently. The overhead caused by the repeating field names can be well managed with compression (e.g., gzip, zstd, brotli).
Some systems split larger exports into smaller parts, so that one is also confronted with multiple JSONLines files. These can be processed in R at the same time and so loading is significantly shortened.
library(furrr)
# my machine has more than 30 cores and a quite fast SSD
# Therefore, we can utilises 20 cores
plan(multisession, workers = 20)
df <- future_map_dfr(
# this returns a list containing all my jsonline files
list.files(path = "../data/panel", pattern="00*", full.names=T),
# each file is parsed separately
function(f) jsonlite::stream_in(file(f))
)
This code selects all files from a folder which match a specific pattern and loads them in parallel. In this example case the data is not compressed, but that would not be a problem either. For example, gzip-compressed files can be processed directly with the gzfile(.) connection (other connection types can be found in the documentation).
|
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|
https://groupcmg.wordpress.com/2010/05/13/math-today-13052010/
|
## Math TOday (13/05/2010) ខែឧសភា 13, 2010
Posted by fidele007 in គណិតវិទ្យា.
Today’s a holiday, but that doesn’t mean it’s not the time for another math challenge! Solve the following integral:
$I=\int\cos2xcos4xcos8x...cos2^{n}x dx$
It seems all problems are always integration, let’s tackle a different one:
Solve the following equation:
$\frac{(1-2sinx)cosx}{(1+2sinx)(1-sinx)}=\sqrt{3}$
Well, have a nice holiday, everybody! 😉
## មតិ»
No comments yet — be the first.
|
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|
https://www.gamedev.net/forums/topic/347033-alpha-blending-issue/
|
Alpha Blending Issue
This topic is 4748 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.
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The subject line makes it sound like a simple problem...well maybe it is, but I certainly can't figure it out. I have had alpha textures working in my engine...still do, but I have some that have just plain stopped working. It's not the texture as I've been able to get the same texture working elsewhere. Anyway the problem is this. I have a sprite being drawn and the alpha is appearing black. I have blending enabled with alpha, but it's like it's not picking up the alpha. The strange part is if I manually pull down the alpha by doing a glColor4f(1.0f, 1.0f, 1.0f, 0.5f); the visible pixel colors are faded by half but the black part remains solid...even behind the color part of the image. It's like there is a black sprite behind the sprite I'm drawing if that makes sense. Here is some sample code...
edgl* dgl = edgl::getInstance();
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glTranslatef(GLfloat(pos.x),GLfloat(pos.y), GLfloat(pos.z));
glScalef(size.X,size.Y,1.0f);
glRotatef(rot,0.0f,0.0f,1.0f);
glBindTexture(GL_TEXTURE_2D, image);
dgl->drawSprite(); //draws two trianges for a quad
glPopMatrix();
Now if I add in... glAlphaFunc(GL_GREATER, 0.5); glEnable(GL_ALPHA_TEST); ...it pulls out the alpha of the texture and shows just the color data, but it tends to be a bit harsh on the edges and not as nicely faded as the blend mode. This code was working, but isn't anymore. I have been trying to track down the cause for days with now luck. I understand that there is probably something else in my engine that is causing this behavior, but I just though I would put this out there to see if anyone knew what it might be. I'm hoping it's something simple I'm just overlooking. Thanks in advance.
Share on other sites
Are you rendering your transparent objects in back-to-front order after all opaque objects are rendered? I have to go soon so can't elaborate right now but I will later if no one else has by then (if this is even the problem).
Share on other sites
Yes I am drawing in the correct order. I'm not sure that is the problem though...for instance I have a tile grid that is using alphas and that works correctly. I draw the sprite on top of that and it is not coming up transparent.
Example...
Share on other sites
and you are certain that texture has an alpha channel?
Share on other sites
Absolutely. If I view the image in my resource editor or in the image viewer in the engine it shows it with the alpha transparent, but for some reason as an entity object it is not showing correctly.
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5. 5
frob
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×
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|
http://www.zentralblatt-math.org/zmath/en/search/?q=an:1234.83001&format=complete
|
Language: Search: Contact
Zentralblatt MATH has released its new interface!
For an improved author identification, see the new author database of ZBMATH.
# Simple Search
Query:
Enter a query and click »Search«...
Format:
Display: entries per page entries
Zbl 1234.83001
Frolov, Valeri P.; Zelnikov, Andrei
Introduction to black hole physics.
(English)
[B] Oxford: Oxford University Press. xvi, 488~p. \sterling~55.00 (2011). ISBN 978-0-19-969229-3/hbk
In general relativity, there are solutions of the field equations (like the Schwarzschild and the Kerr metrics) which represent strong field configurations having the feature that the curvature manifests itself in unusual global properties of space-time. Since the time when J. A. Wheeler and others gave them the name black holes', more and more relativists considered them as astrophysical objects. Black holes were assumed to be possible end stages of the star development and thus became an object of astrophysical considerations. Wheeler and colleagues had still strong criteria to be imposed on possible physical matter, i.e., on its energy-momentum tensor. These limitations and the fact that the known black hole solutions are singular led them to conclude that there is no such solution of the classical (i.e., not quantized) gravitation field equations. In the hope to arrive at regular classical black hole (and cosmological) solutions, at that time many authors tried to modify Einstein's gravitational field equations. Now, the situation has changed: mostly, without having developed a quantized general relativity (Quantum Gravity'), one relies on that a future Quantum Gravity will solve the singularity problem such that one can consider the black hole solutions to Einstein's classical equations as space-times physically interpretable up to the Planck regime. This is also the standpoint of the authors of the present book. They are of the opinion that after 40 years of black hole discussion by relativists and astrophysical discoveries supporting the belief in the existence of black holes (the observation of pulsars is considered to be the beginning of such discoveries), we cannot imagine our world without black holes". \par This is the second comprehensive book by V. P. Frolov on black holes, now co-authored by A. Zelnikov, while its 1998 forerunner was written together with I. D. Novikov [{\it V.P. Frolov} and {\it I.D. Novikov}, Black hole physics. Basic concepts and new developments. Dordrecht: Kluwer Academic Publishers (1998; Zbl 0978.83001)]. The book is based on lectures that Frolov has given at different universities during 30 years. The main part (presented in Chapters 1-8) provides one with material sufficient for a one-term self-consistent course on black holes. After giving a survey over this fast developing area of research, general relativity is prepared by chapters on physics in accelerated reference frames in Minkowski space, Riemannian geometry, and particle motions in curved space-time. Chapter 5 introducing Einstein's equations and discussing gravitational radiation and gravity in higher-dimensions is followed by three chapters devoted to spherically symmetric and rotating black holes. Besides very informative appendices, in Chapters 9 and 10, the book also contains additional material, e.g., concerning classical and quantum fields near black holes, black holes and higher dimensions, wormholes, and `time machines'. \par This book is a very good basis for teaching graduate courses on black holes. Moreover, in view of the diversity of considered topics reaching from mathematics over special and general relativity theory to astrophysics, this book deserves a great readership going beyond readers who are particularly interested in black hole physics.
[Horst-Heino von Borzeszkowski (Berlin)]
MSC 2000:
*83-01 Textbooks (relativity)
83C57 Black holes
83C15 Closed form solutions of equations in general relativity
83F05 Relativistic cosmology
83C35 Gravitational waves
83A05 Special relativity
83C10 Equations of motion
85A40 Nonrelativistic cosmology
83C47 Quantum field theory on curved space-times
83C75 Space-time singularities, etc.
85A15 Galactic and stellar structure
83D05 Relativistic gravitational theories other than Einstein's
Keywords: black holes; general relativity; Schwarzschild metric; Kerr metric; classical and quantum fields in curved spaces
Citations: Zbl 0978.83001
Highlights
Master Server
|
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|
https://questions.examside.com/past-years/jee/question/if-both-the-roots-of-the-quadratic-equation-x2-mx-4-jee-main-mathematics-trigonometric-functions-and-equations-20mnozh6berg7pgn
|
1
### JEE Main 2019 (Online) 9th January Evening Slot
If both the roots of the quadratic equation x2 $-$ mx + 4 = 0 are real and distinct and they lie in the interval [1, 5], then m lies in the interval :
A
($-$5, $-$4)
B
(4, 5)
C
(5, 6)
D
(3, 4)
## Explanation
x2 $-$mx + 4 = 0
Case-I :
D > 0
m2 $-$ 16 > 0
$\Rightarrow$ m $\in$ ($-$ $\infty$, $-$ 4) $\cup$ (4, $\infty$)
Case-II :
$\Rightarrow \,\,1 < {{ - b} \over {2a}} < 5$
$\Rightarrow \,\,1 < {m \over 2} < 5 \Rightarrow \,m \in \left( {2,10} \right)$
Case-III :
f(1) > 0 and f(5) > 0
1 $-$ m + 4 > 0 and 25 $-$ 5m + 4 > 0
m < 5 and m < ${{29} \over 5}$
Case-IV :
Let one root is x = 1
1 $-$ m + 4 = 0
m = 5
Now equation x2 $-$ 5x + 4 = 0
(x $-$ 1) (x $-$ 4) = 0
x = 1 i.e. m = 5 is also included
hence m $\in$ (4, 5]
So given option is (4, 5)
2
### JEE Main 2019 (Online) 9th January Evening Slot
The number of all possible positive integral values of $\alpha$ for which the roots of the quadratic equation, 6x2 $-$ 11x + $\alpha$ = 0 are rational numbers is :
A
3
B
2
C
4
D
5
## Explanation
For rational D must be perfect square
D = 121 $-$ 24$\alpha$
for 121 $-$ 24$\alpha$ to be perfect square a must be 3, 4, 5
So, ans $\alpha$ = 3
3
### JEE Main 2019 (Online) 10th January Morning Slot
Consider the quadratic equation (c – 5)x2 – 2cx + (c – 4) = 0, c $\ne$ 5. Let S be the set of all integral values of c for which one root of the equation lies in the interval (0, 2) and its other root lies in the interval (2, 3). Then the number of elements in S is -
A
12
B
18
C
10
D
11
## Explanation
Let f(x) = (c $-$ 5)x2 $-$ 2cx + c $-$ 4
$\therefore$ f(0)f(2) < 0 . . . . .(1)
& f(2)f(3) < 0 . . . . .(2)
from (1) and (2)
(c $-$ 4)(c $-$ 24) < 0
& (c $-$ 24)(4c $-$ 49) < 0
$\Rightarrow$ ${{49} \over 4}$ < c < 24
$\therefore$ s = {113, 14, 15, . . . . . 23}
Number of elements in set S = 11
4
### JEE Main 2019 (Online) 10th January Evening Slot
The value of $\lambda$ such that sum of the squares of the roots of the quadratic equation, x2 + (3 – $\lambda$)x + 2 = $\lambda$ has the least value is -
A
1
B
2
C
${{15} \over 8}$
D
${4 \over 9}$
## Explanation
$\alpha$ + $\beta$ = $\lambda$ $-$ 3
$\alpha $$\beta = 2 - \lambda \alpha 2 + \beta 2 = (\alpha + \beta )2 - 2\alpha$$\beta$ = ($\lambda$ $-$ 3)2 $-$ 2$\left( {2 - \lambda } \right)$
= $\lambda$2 + 9 $-$ 6$\lambda$ $-$ 4 + 2$\lambda$
= $\lambda$2 $-$ 4$\lambda$ + 5
= ($\lambda$ $-$ 2)2 + 1
$\therefore$ $\lambda$ = 2
|
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|
https://www.vedantu.com/question-answer/given-that-the-principalrs3500-interestrs700-and-class-8-maths-cbse-5ee351bda32ce0560cdac88e
|
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# Given that the principal=Rs.3500, Interest=Rs.700, and rate=5% p.a. Calculate the time period.
Last updated date: 26th Mar 2023
Total views: 307.2k
Views today: 4.85k
Verified
307.2k+ views
Hint: Make use of the formula of simple interest and find out a formula for time period and calculate the time period from the data given.
We know that $SI = \dfrac{{PTR}}{{100}}$
So, we get time period T=$\dfrac{{SI \times 100}}{{P \times R}}$
T=$\dfrac{{700 \times 100}}{{3500 \times 5}}$
T=$\dfrac{{70000}}{{17500}} = 4$
|
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|
https://fermatslibrary.com/s/q-2020-12-24-378
|
The three types of normal sequential effect algebras
Abraham Westerbaan
1
, Bas Westerbaan
1,2
, and John van de Wetering
1
1
2
University College London
A sequential effect algebra (SEA) is an effect algebra equipped with a sequential
product operation modeled after the uders product
(
a, b
)
7→
ab
a on C
-algebras.
A SEA is called normal when it has all suprema of directed sets, and the sequential
product interacts suitably with these suprema. The effects on a Hilbert space and the
unit interval of a von Neumann or JBW algebra are examples of normal SEAs that are
in addition convex, i.e. possess a suitable action of the real unit interval on the algebra.
Complete Boolean algebras form normal SEAs too, which are convex only when
0 = 1
.
We show that any normal SEA E splits as a direct sum E
=
E
b
E
c
E
ac
of a
complete Boolean algebra E
b
, a convex normal SEA E
c
, and a newly identified type of
normal SEA E
ac
we dub purely almost-convex.
Along the way we show, among other things, that a SEA which contains only idem-
potents must be a Boolean algebra; and we establish a spectral theorem using which
we settle for the class of normal SEAs a problem of Gudder regarding the uniqueness of
square roots. After establishing our main result, we propose a simple extra axiom for
normal SEAs that excludes the seemingly pathological a-convex SEAs. We conclude
the paper by a study of SEAs with an associative sequential product. We find that
associativity forces normal SEAs satisfying our new axiom to be commutative, shed-
ding light on the question of why the sequential product in quantum theory should be
non-associative.
1 Introduction
Understanding the properties and foundations of quantum theory requires contrasting it with
hypothetical alternative physical theories and mathematical abstractions. By studying these alter-
natives it becomes clearer which parts of quantum theory are special to it, and which are present
in any reasonable physical theory.
A framework that has been used extensively to study such alternatives is that of generalised
probabilistic theories (GPTs) [6]. GPTs have built into their definition the classical concepts of
probability theory, and so the state and effect spaces of hypothetical physical systems are modelled
by convex sets. While convexity is a useful and powerful property, it precludes the study of physical
theories that have a more exotic notion of probability. For instance, deterministic or possibilistic
‘probabilities’ studied in contextuality [1, 48] or systems where probabilities can vary spatially [12].
To study systems with this broader notion of probability, a more general structure than convex
sets is needed. This paper is about effect algebras, which were introduced in 1994 by Foulis and
Bennett [13].
Effect algebras generalise and abstract the unit interval of effects in a C
-algebra. The study
of effect algebras has become a flourishing field on its own [7, 10, 14, 24, 27, 35, 45] and covers a
variety of topics [34, 36, 47, 51]. An effect algebra that has an action of the real unit interval on it
is called a convex effect algebra [25]. Such effect algebras essentially recover the standard notion
of an effect space in GPTs.
Abraham Westerbaan: [email protected]
Bas Westerbaan: [email protected]
John van de Wetering: [email protected]
Accepted in Quantum 2020-12-22, click title to verify. Published under CC-BY 4.0. 1
arXiv:2004.12749v2 [quant-ph] 22 Dec 2020
Effect algebras, or even just convex effect algebras are very general structures. So, as in
GPTs where additional assumptions are often needed on the physical theory to make interesting
statements, we will impose some additional structure on effect algebras.
The effects of a quantum system, i.e. the positive subunital operators on some Hilbert space or,
more generally, positive subunital elements of a C
-algebra or Jordan algebra, have some interesting
algebraic structure (aside from the effect algebra operations). The one we focus on in this paper
is the sequential product, also known as the L¨uders product
(
a, b
)
7→
ab
a. This product models
the act of first measuring the effect a and then measuring the effect b.
In order to study the sequential product in the abstract, Gudder and Greechie introduced in
2002 [20] the notion of a sequential effect algebra (SEA), that models the sequential product on
an effect algebra as a binary operation satisfying certain properties. SEAs have been studied by
several authors, see e.g. [1618, 21, 22, 28, 38, 39, 49, 52, 53, 55, 58, 61].
Adopting the language of GPTs (and specifically that of reconstructions of quantum theory) we
can view the assumed existence of a sequential product on our effect algebras as a physical postulate
(indeed, such a sequential product has been used for a reconstruction of quantum theory before [55]).
But as is the case for GPTs, we will also need some structural ‘background’ assumption. Indeed,
in most work dealing with GPTs it is assumed that the sets of states and effects are closed in a
suitable topology. This models the operational assumption that when we can arbitrarily closely
approximate an effect, that this effect is indeed a physical effect itself. Such assumptions are
routinely used to, for instance, remove the possibility of infinitesimal effects.
In a (sequential) effect algebra we however have no natural notion of topology and hence no
direct way to require such a closure property. But as an effect algebra is a partially ordered set, we
can require that this order is directed complete, meaning that any upwards directed subset has a
supremum. Indeed, this condition is routinely used in theoretical computer science to give meaning
to algorithms with loops or recursion in a branch called domain theory [2]. In the field of operator
algebras, one possible characterisation of von Neumann algebra’s is that they are C
-algebras that
are bounded directed-complete and have a separating set of normal states [40, 46, 60].
Motivated by the structure of von Neumann algebras, we call a sequential effect algebra normal
when every directed set has a supremum, the sequential product preserves these suprema in the
second argument, and an effect commutes with such a suprema provided it commutes with all
elements in the directed set. The set of effects on a Hilbert space is a convex normal SEA. More
generally, the unit interval of any JBW-algebra (and so in particular that of any von Neumann
algebra) is also a convex normal SEA [56]. As a rather different example, any complete Boolean
algebra is a normal SEA, which is not convex.
A priori, a (normal) SEA is a rather abstract object and there could potentially be rather exotic
examples of them. The main result of this paper is to show that for normal SEAs this is, in a
sense, not the case.
We will show that any normal SEA is isomorphic to a direct sum E
b
E
c
E
ac
, where E
b
is
a complete Boolean algebra, E
c
is a convex normal SEA and E
ac
is a normal SEA that is purely
a-convex, a new type of effect algebra we will define later on. We will show there is no overlap: for
instance, there is no normal SEA that is both purely a-convex and Boolean.
In much the same way as a C
-algebra is the union of its commutative subspaces, we show
that a purely a-convex SEA is a union of convex SEAs. Hence, normal SEAs come essentially in
two main types: Boolean algebras that model classical deterministic logic, and convex SEAs that
fit into the standard GPT framework. Hence, rather than having convex structure as a starting
assumption, we show that it can be derived as a consequence of our other assumptions.
Along the way we will establish several smaller results that might be of independent interest.
We show any SEA where all elements are sharp (i.e. idempotent) is a Boolean algebra, and that
consequently any SEA with a finite number of elements is a Boolean algebra. We introduce a
new axiom for SEAs that exclude the seemingly pathological purely a-convex SEAs. Combining
this with our main result shows that normal SEAs satisfying this additional axiom neatly split up
into a Boolean algebra and a convex normal SEA. Finally, we study SEAs where the sequential
product is associative. We find that associative normal SEAs satisfying our additional axiom must
be commutative, and we are able to completely classify the associative normal purely a-convex
factors, i.e. SEAs with trivial center.
This work relies on recent advances made in the representation theory of directed-complete
Accepted in Quantum 2020-12-22, click title to verify. Published under CC-BY 4.0. 2
effect monoids [59]. An effect monoid is an effect algebra with an additional associative (not
necessarily commutative) multiplication operation that is additive in both arguments. Crucially,
any commutative normal SEA is a directed-complete effect monoid.
Section 2 contains the basic definitions and recalls the necessary results from [59]. Then in
Section 3 we show that a (normal) SEA where every element is idempotent must be a (complete)
Boolean algebra. In Section 4 we prove our main technical results that show that any normal
SEA splits up into a Boolean algebra and an a-convex normal SEA. Then in Section 5 we improve
this result by showing that an a-convex normal SEA splits up into a convex part and a purely
a-convex part, and we introduce a new axiom that excludes the seemingly pathological purely a-
convex normal SEAs. In Section 6 we study the consequences of our representation theorem for the
existence of non-commutative associative sequential products. Finally, in Section 7 we speculate
on possible future avenues and consequences of our results.
2 Preliminaries
Definition 1.
An
effect algebra
(EA) [
13
] is a set
E
with distinguished element 0
E
, partial
binary operation
>
(called
sum
) and (total) unary operation
a 7→ a
(called
complement
),
satisfying the following axioms, writing a b whenever a > b is defined and defining 1 := 0
.
Commutativity: if a b, then b a and a > b = b > a.
Zero: a 0 and a > 0 = a.
Associativity: if
a b
and (
a > b
)
c
, then
b c
,
a
(
b > c
), and (
a > b
)
> c
=
a >
(
b > c
).
The complement a
is the unique element with a > a
= 1.
If a 1, then a = 0.
For
a, b E
we write
a b
whenever there is a
c E
with
a > c
=
b
. This turns
E
into a poset
with minimum 0 and maximum 1. The map
a 7→ a
is an order anti-isomorphism. Furthermore,
a b
if and only if
a b
. If
a b
, then the element
c
with
a > c
=
b
is unique and is denoted
by b a.
Remark 2.
We pronounce
a b
as
a
is summable with
b
. In the literature this is more often
referred to as orthogonality, but we avoid this terminology, as it clashes with the orthogonality for
sequential effect algebras we will see in Definition 15. We use the symbol
>
to denote the effect
algebra sum following for instance [8, 33]. The symbol is also commonly used in the literature.
Example 3.
Let
B
be a Boolean algebra (or more generally, an orthomodular poset [
31
,
43
,
44
].)
Then
B
is an effect algebra with the partial addition defined by
x y x y
= 0 and in that
case
x> y
=
xy
. The complement, ( )
, is given by the complement, ( )
(or the orthocomplement
for an orthomodular lattice.) The lattice order coincides with the effect algebra order (defined
above). See e.g. [61, Prop. 27] or [13, §5].
Example 4.
Let
G
be an ordered abelian group (such as an ordered vector space, for example a
C
-algebra,) and let
u G
be any positive element. Then any interval [0
, u
]
G
=
{a G
; 0
a u}
forms an effect algebra, where the effect algebra sum
a > b
of
a
and
b
from the interval is defined
when
a
+
b u
and in that case coincides with the group addition:
a > b
=
a
+
b
. The complement
is given by a
= u a. The effect algebra order on [0, u]
G
coincides with the regular order on G.
In particular, the set of effects [0
,
1]
C
of a unital C
-algebra
C
forms an effect algebra with
a b a + b 1, and a
= 1 a.
Remark 5.
In GPTs, the set of effects of a system is often modelled by the unit interval of an
ordered vector space. Hence, the above example demonstrates how these effect spaces fit into
the notion of an effect algebra. The corresponding addition of effects in a GPT is often called
coarse-graining.
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Example 6.
If
E
and
F
are effect algebras, then its Cartesian product
E F
with component-wise
operations is again an effect algebra.
1
We will often implicitly use the following basic facts about effect algebras.
Proposition 7. In any effect algebra we have (see e.g. [11] or [62, §175V])
1. (involution) a
⊥⊥
= a;
2. (positivity) if a > b = 0, then a = 0 and b = 0;
3. (cancellation) if a > b = a > c, then b = c;
4. a b iff b
a
and
5. a b iff a b
.
Some effect algebras are more closely related to ordered vector spaces (like the example of a
C
-algebra above or the effect spaces coming from a GPT). We call these effect algebras convex:
Definition 8.
A
convex action
on an effect algebra
E
is a map
·
: [0
,
1]
×E E
, where [0
,
1] is
the regular unit interval, obeying the following axioms for all a, b E and λ, µ [0, 1]:
λ · (µ · a) = (λµ) ·a.
If λ + µ 1, then λ · a µ · a and λ · a > µ · a = (λ + µ) · a.
1 · a = a.
λ · (a > b) = λ · a > λ · b.
A
convex effect algebra
[
25
] is an effect algebra endowed with such a convex action
2
. We will
say that an effect algebra E is convex when there is at least one convex action on E.
Example 9.
Let
V
be an ordered real vector space (such as the space of self-adjoint elements of
a C
-algebra). Then any interval [0
, u
]
V
where
u
0 is a convex effect algebra with the obvious
action of the real unit interval. Conversely, for any convex effect algebra
E
, we can find an ordered
real vector space
V
and
u V
such that
E
is isomorphic as a convex effect algebra to [0
, u
]
V
[
26
].
Remark 10.
Convex effect algebras have been well-studied, see e.g. [
19
,
32
,
36
,
53
,
54
]. In
the literature on effectus theory, convex effect algebras are also called effect modules [
8
,
9
]. In
Definition 45 we introduce a-convex (almost convex) effect algebras, by dropping the last axiom.
Definition 11.
Let
E
be a partially ordered set (such as an effect algebra). A subset
S
of
E
is
called
directed
when it is non-empty, and for any
a, b S
there exists a
c S
such that
a, b c
.
We say that E is directed complete when every directed subset S of E has a supremum,
W
S.
Example 12. Any complete Boolean algebra is a directed-complete effect algebra.
Example 13.
Let
A
be a unital C
-algebra. Then [0
,
1]
A
is a directed-complete effect algebra
if and only if
A
itself is bounded-directed complete, that is: if every bounded set of self-adjoint
elements has a least upper bound. Such C
-algebras are called monotone complete or monotone
closed, [
41
,
§
2], and include all von Neumann algebras. A commutative unital C
-algebra, being
of the form
C
(
X
) for some compact Hausdorff space
X
, is bounded-directed complete if and only
if X is extremally disconnected [15, Sections 1H & 3N.6].
Remark 14.
Because the complement acts as an order anti-isomorphism, a directed-complete
effect algebra also has infima for all
filtered
, i.e. downwards directed, sets. In particular, if we
have a decreasing sequence
a
1
a
2
a
3
···
in a directed-complete effect algebra, then this has
an infimum
V
n
a
n
.
1
This is in fact a categorical product with the obvious projectors and as morphisms maps
f
with:
f
(1) = 1
and a b implies f (a) f(b) and f(a) > f(b) = f(a > b).
2
Usually, a convex effect algebra is defined simply as an effect algebra
E
where for every
a E
and
λ
[0
,
1]
there is an element
λa E
satisfying the axioms above. However, in this paper we face the possibility of an effect
algebra having many inequivalent convex actions. This is why we are explicit in defining a convex effect algebra as
an effect algebra equipped with a convex action.
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2.1 Sequential effect algebras
We now come to the definition of the central object of study of this paper, the sequential effect
algebra. Before we give the formal definition, let us give some motivation for the assumptions we
will require. The sequential product a b of two effects a and b represents the sequential measure-
ment of first a and then b. An important difference between classical and quantum systems is that
in a classical system we can measure without disturbance, and hence the order of measurement is
not important: a b
=
b a for all effects a and b. In a quantum system this is generally not the
case, and the order of measurement is important. However, what is interesting in quantum theory
is that some measurements are compatible, meaning that the order of measurement for those mea-
surements is not important.
3
We will use the symbol a | b to denote that a and b are compatible
effects. For such compatible effects a, b and c we can expect that doing ‘classical operations’ or
‘classical post-processing’ on these effects retains compatibility. For instance, if a | b, and we negate
the outcome of a to get a
, we still expect a
| b, as negation can be done classically without
interacting with the quantum system. Similarly, we would expect a | b > c, as addition of effects
corresponds to classically coarse-graining the measurement outcomes.
Let us now give the formal definition:
Definition 15.
A
sequential effect algebra
(SEA) [
20
]
E
is an effect algebra with an additional
(total) binary operation
, called the
sequential product
, satisfying the axioms listed below,
where a, b, c E. Elements a and b are said to commute, written a | b, whenever a b = b a.
S1. a (b > c) = a b > a c whenever b c.
S2. 1 a = a.
S3. a b = 0 = b a = 0.
S4. If a | b, then a | b
and a (b c) = (a b) c for all c.
S5. If c | a and c | b then also c | a b and if furthermore a b, then c | a > b.
A SEA E is called normal when E is directed complete, and
S6. Given directed S E we have a
W
S =
W
sS
a s, and a |
W
S when a | s for all s S.
We say
E
is
commutative
whenever
a | b
for all
a, b E
. An element
a E
is
central
if it
commutes with every element in
E
. The
center Z
(
E
) of
E
is the set of all central elements. We
call
p E
an
idempotent
whenever
p
2
=
p p
=
p
(or equivalently
p p
= 0). We call
E Boolean
if every element is an idempotent
4
. We say a, b E are orthogonal, provided that a b = 0.
The discussion above Definition 15 should make clear why we have axioms S2, S4 and S5. Axiom
S3 is less operationally motivated, but is a useful property as it makes the notion of orthogonality
well-behaved. Axiom S6 is our way of stating continuity of the product without having access to
an actual topology. Indeed, if E is the unit interval of a von Neumann algebra, then Axiom S6 says
that the product is ultraweakly continuous in the second argument. Axiom S1 can be understood
operationally as follows. Consider an ensemble of systems all prepared in the same state and that
we measure them all with the effect a. We then measure some of the states with b and others with
c. By adding up the probabilities of success of these measurement outcomes we model the effect
a
(
b > c
)
as we have a and then b or c’. Alternatively, we could measure one half of the states
with a b and the other with a c and add up the outcomes to get
(
a b
)
>
(
a c
)
. But looking at
the interactions we have with the system, these two protocols are obviously equivalent, and hence
we should have a
(
b > c
) = (
a b
)
>
(
a c
)
. Note that we do not in general expect this property
to hold in the other argument:
(
a > b
)
c 6
= (
a c
)
>
(
b c
)
. Indeed, the addition is a classical
operation, and there is no way in general to perform the measurement
(
a > b
)
c as it requires the
measurement a or b to be performed on a single system.
The motivating example of a (normal) sequential effect algebra is the unit interval of a C
-algebra:
3
The word ‘compatible’ is used for this purpose when it comes to sequential effect algebras [
20
]. However, in
other parts of the literature ‘compatible’ is used for a different notion, and the term ‘non-disturbing’ might be used
4
We will see that a Boolean SEA is a Boolean algebra, see Proposition 44.
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Example 16.
If
A
is a C
-algebra, then the EA [0
,
1]
A
is a SEA with the sequential product
defined by
a b
:=
ab
a
, see [
20
]. If
A
is furthermore bounded-directed complete (for instance if
it is a von Neumann algebra), then [0
,
1]
A
is a normal SEA with the same sequential product. It is
also possible to define a sequential product using only the Jordan algebra structure. In particular,
any JB-algebra is a convex SEA, while any JBW-algebra is a convex normal SEA. For the details
we refer to [56].
We will use the following properties without further reference in the remainder of the paper.
Proposition 17 (Cf. §3 of [20]). Let E be a SEA with a, b, c, p E with p idempotent.
1. a 0 = 0 a = 0 and a 1 = 1 a = a.
2. a b a.
3. If a b, then c a c b.
4. p a iff p a = p iff a p = p iff a
p = 0 iff p a
= 0.
5. a p iff p a = a iff a p = a iff a p
= 0 iff p
a = 0.
6. p
is idempotent.
7. If p a, then a is idempotent if and only if p > a is idempotent.
Proof.
Concerning 1: Since 0 = 0
>
0 by S1, we have
a
0 =
a
0
> a
0, and so
a
0 = 0, by
cancellativity of the addition in an effect algebra. Then 0
a
= 0 too, by S3. In particular,
a |
0,
and so a | 0
= 1, by S4. With S2, we get a 1 = 1 a = a.
Point 3: when
a b
, we have
b
=
a >
(
b a
), and so
c b
=
c a > c
(
b a
)
c a
, by S1.
Taking b = 1, we get c a c 1 = c, by 1, and so we have 2.
To show pt. 5, we will prove that we have the implications
a p p
a
= 0
a p
=
0
a p
=
a p a
= 0
a p
and thus they are all equivalent. So first suppose that
a p
.
Then
p
a p
p
= 0, by 3, so
p
a
= 0. Now suppose instead that
p
a
= 0, which is
equivalent to
a p
= 0 by S3, which in turn is equivalent to
a
=
a
1 =
a
(
p > p
) =
a p
by S2.
Since then
a | p
, we get
a | p
, by S4, and so
p a
=
a p
=
a
. Since
p a
=
a
on its own entails
that a p, by 2, we are back where we started, and therefore done.
For 4, note that
p a
iff
a
p
iff
a
p
= 0 iff
p a
= 0 by 5. Moreover, since
p a
=
p
is equivalent to
p a
= 0 by S1, and
a p
=
p
entails
p a
by 2, the only thing left to show is
that
p a
implies
a p
=
p
. So suppose that
p a
a
p
= 0 =
p a
= 0
and
p a
=
p
. Since thus
a | p
, and so
a | p
by S4, we get
a p
=
p a
=
p
. We continue with
pt. 6. Note that
a
is idempotent iff
a a
= 0. Thus
p p
= 0 and so
p
p
= 0 by S3. Hence
p
is indeed idempotent.
Finally, we move to point 7. Assume
a
is idempotent. Clearly
p p > a
and so (
p > a
)
p
=
p
by 4. Similarly (
p > a
)
a
=
a
. Thus (
p > a
)
(
p > a
) = ((
p > a
)
p
)
>
((
p > a
)
a
) =
p a
, as desired.
Conversely, assume
p > a
is an idempotent. Note
p
and (
p > a
)
are summable idempotents and so
by the previous point
a
=
p
>
(
p > a
)
is idempotent as well. Thus
a
is indeed idempotent.
The next five lemmas were originally proven in [59] for effect monoids, and we will need them
for our results in the context of SEAs.
Lemma 18.
Let
E
be a SEA with
p, a, b E
and
p
idempotent. If
a, b p
and
a > b
exists,
then a > b p.
Proof.
Because
a p
, we have
p
a
= 0. Since similarly,
p
b
= 0, we have
p
(
a > b
) = 0, and
so a > b p.
Lemma 19. In a SEA, a a
is summable with itself for any element a.
Proof.
Note that since
a | a
, we have
a | a
by S4, or in other words
a a
=
a
a
. Since
1 =
a> a
=
a
(
a> a
)
> a
(
a> a
) =
a a > a a
> a
a > a
a
=
a
2
>
2(
a a
)
>
(
a
)
2
,
we see that a a
is indeed summable with itself.
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Lemma 20.
Let
E
be a directed-complete effect algebra, and let
S E
be some directed non-empty
subset. Let a E be such that a s for all s S. Then a
W
S and a >
W
S =
W
sS
a > s.
Proof.
The map
b 7→ a > b
, giving an order isomorphism from [0
, a
]
E
to [
a,
1]
E
(with inverse
b 7→ b a
,) preserves (and reflects) suprema. In particular,
W
S
, the supremum of
S
in
E
, which is
the supremum of
S
in [0
, a
]
E
too, is mapped to
W
sS
a > s
, the supremum of the
a > s
in
E
, and
in [a, 1]
E
too.
Lemma 21.
The only element
a
of a directed-complete effect algebra
E
for which the
n
-fold
sum na exists for all n is zero.
Proof. We have a >
W
n
na =
W
n
a > na =
W
n
(n + 1)a =
W
n
na, and so a = 0.
Lemma 22. Let E be a normal SEA and suppose a E satisfies a
2
= 0. Then a = 0.
Proof.
Since
a
2
= 0 we have
a
=
a
1 =
a
(
a > a
) =
a a
, and hence (see Lemma 19)
a
is
summable with itself. But furthermore (a > a)
2
= 4a
2
= 0, and so (a > a)
2
= 0.
Continuing in this fashion, we see that 2
n
a
exists for every
n N
and (2
n
a
)
2
= 0. Hence, for
any m N the sum ma exists so that by Lemma 21, we have a = 0.
Proposition 23.
Assume
E
is a SEA with idempotent
p E
. Write
p E
:=
{p a
;
a E}
for
the
left corner
by
p
. The sequential product of
E
restricts to
p E
and in fact, with partial sum
and zero of
E
and complement
a 7→ p a
, the set
p E
is an SEA. If
E
is normal, then
p E
is
normal as well.
Proof.
By Prop. 17 we have
p E
=
{a
;
a E a p}
and so
p E
is an effect algebra. For
a, b
p E
, we have
a b a p
and so
a b p E
. As the sequential product, zero and addition
of
p E
and
E
coincide almost all axioms for an SEA hold trivially. Only the first part of S4
(which involves the orthocomplement) remains. So assume
a, b p E
with
a | b
. We have to show
that
a | pb
. Note
a p
= 0 and so
a | p
. Thus by S5, we have
a | b> p
and as
b> p
= (
pb
)
we have by S4 (for E), a | p b. Thus p E is indeed an SEA.
Now assume
E
is normal. As a principal downset of
E
, the suprema computed within
p E
are the same as computed in
E
and so
p E
is directed complete. As additionally the sequential
product of p E is the restriction of that of E, the axiom S6 holds trivially.
Proposition 24. Let p be a central idempotent in a SEA E. Then E
=
p E p
E.
Proof.
Note that the map
a 7→
(
p a, p
a
) is additive and unital. It is order reflecting, because if
p a p b
and
p
a p
b
then
a
=
a p > a p
=
p a > p
a p b > p
b
=
b
, using
the centrality of
p
(and hence
p
by S4). It is obviously surjective because for
a p E
we have
p a = a, and similarly for b p
E, and hence a > b 7→ (a, b).
To show that it preserves the sequential product we note that
p (a b) = (p a) b = (p (p a)) b = ((p a) p) b = (p a) (p b)
and similarly for p
.
Definition 25.
We call an idempotent
p E Boolean
when
p E
is Boolean, i.e. when all
a p
in E are idempotent.
The following definition and result will be crucial for our arguments, as it relates sequential
effect algebras to commutative effect monoids (see next section).
Definition 26.
Let
S E
be a subset of elements of a SEA
E
. The
commutant of S
is defined
as S
0
:= {a E; a | s for all s S}. The bicommutant of S is defined simply as S
00
:= (S
0
)
0
.
Remark 27.
Let
H
be some Hilbert space, and let
E
= [0
,
1]
B(H )
. For any
a E
, the
bicommutant
{a}
00
is the set of effects of the least commutative von Neumann algebra of
B
(
H
)
containing
a
by the bicommutant theorem. In general this is false, consider for instance
E
= [0
,
1]
2
(with component-wise standard product) and
a
= (0
,
1) then
{a}
00
=
E
, while
{
0
} ×
[0
,
1] is a
smaller commutative subalgebra containing a.
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Proposition 28
(Cf. [
53
], Proposition III.12)
.
Let
S E
be a set of mutually commuting elements
in a normal SEA E, then S
00
is a commutative normal SEA.
Proof.
To start off, assume
S E
an arbitrary subset of
E
. Clearly 0
,
1
S
0
. If
a, b S
0
, then for
any
s S
, we have
a | s
and
b | s
so that
a b | s
and
a
| s
. If
a b
, then
a > b | s
. Thus
S
0
is
closed under partial sum, complement and sequential product. As a direct axiom of a normal SEA,
the set S
0
is also closed under directed suprema. Hence S
0
is a sub-normal-SEA of E.
As
S
was arbitrary, we see that (
S
0
)
0
=
S
00
is a sub-normal-SEA of
E
as well. Assume the
elements of
S
are pairwise commuting. Then
S S
0
so that
S
00
S
0
. By definition
S
00
commutes
with all elements from
S
0
and so in particular with all elements from
S
00
itself. Hence
S
00
is
commutative.
2.2 Effect monoids
Before we can proceed with the theory of (normal) SEAs we must discuss effect monoids. Roughly
speaking, effect monoids are the classical counterparts to SEAs, being endowed with an associative
and biadditive multiplication ·. Note that we do not require an effect monoid to be commutative,
although commutativity often follows automatically, for example, in the (for us relevant) case that
the effect monoid is directed complete.
Definition 29.
An
effect monoid
(EM) is an effect algebra (
M, > ,
0
,
( )
, ·
(total) binary operation ·, such that the following conditions hold for all x, y, z M .
Unit: x · 1 = x = 1 · x.
Distributivity: If
y z
, then
x · y x · z
,
y · x z · x
with
x ·
(
y > z
) = (
x · y
)
>
(
x · z
)
and (y > z) · x = (y · x) > (z ·x). In other words: · is bi-additive.
Associativity: x · (y · z) = (x · y) · z.
We call an effect monoid
M commutative
if
x · y
=
y · x
for all
x, y M
; an element
p
of
M
idempotent
whenever
p
2
=
p · p
=
p
; elements
x
,
y
of
M orthogonal
when
x · y
=
y · x
= 0. An
effect monoid is Boolean if all its elements are idempotents.
Example 30.
Any Boolean algebra (
B,
0
,
1
, , ,
( )
) is an effect algebra by Example 3, and,
moreover, a Boolean commutative effect monoid with multiplication defined by
x · y
=
x y
.
Conversely, any Boolean effect monoid is a Boolean algebra [59, Proposition 47].
Example 31.
The unit interval [0
,
1]
R
of any (partially) ordered unital ring
R
(in which the sum
a + b and product a · b of positive elements a and b are again positive) is an effect monoid.
For example, let
X
be a compact Hausdorff space. The space of continuous complex-valued
functions
C
(
X
) is a commutative unital C
-algebra (and conversely by the Gelfand theorem, any
commutative C
-algebra with unit is of this form) and hence its unit interval [0
,
1]
C(X)
=
{f
:
X
[0, 1]} is a commutative effect monoid.
In [
8
, Ex. 4.3.9] and [
61
, Cor. 51] two different non-commutative effect monoids are constructed.
The latter also provides an example of an effect monoid that is not a SEA (since
e
3
· e
2
= 0, while
e
2
· e
3
= e
5
).
Note that an effect monoid that additionally satisfies the implication a · b
= 0 =
b · a
= 0
is
a SEA.
Example 32.
A commutative SEA is a commutative effect monoid and vice versa. Moreover, a
normal commutative SEA is a directed-complete commutative effect monoid and vice versa
5
.
Remark 33.
In Ref. [
28
], “distributive” sequential effect algebras were introduced. These are the
same thing as effect monoids satisfying the condition a · b = 0 b · a = 0.
Example 34.
Let
M
be an effect monoid and let
p M
be some idempotent. The subset
pM
:=
{p·e
;
e M}
is called the
left corner
by
p
and is an effect monoid with (
p·e
)
:=
p·e
and all other
operations inherited from
M
. The map
e 7→
(
p · e, p
· e
) is an isomorphism
M
=
pM p
M
[
59
,
Corollary 21]. Analogous facts hold for the right corner M p := {e · p; e M}.
5
While the first claim is obvious, the astute reader might notice that the second claim requires showing that the
product in a directed-complete commutative effect monoid is always normal. This is done in [59, Theorem 43].
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2.2.1 Representation theorem for directed-complete effect monoids
We will need the following representation theorem for directed-complete effect monoids from [59].
(In fact, a representation theory for the more general class of ω-directed complete effect monoids
is established there, which we do not need here).
Theorem 35.
[
59
] In every directed-complete effect monoid
M
there is an idempotent
p
such
that
pM
is a convex effect algebra and
p
M
is Boolean. Furthermore, there is an extremally-
disconnected compact Hausdorff space X such that pM
=
[0, 1]
C(X)
.
Corollary 36
(Spectral Theorem for normal SEA)
.
Let
E
be a normal SEA and let
a E
. Then
there is a extremally-disconnected compact Hausdorff space
X
and complete Boolean algebra
B
such that {a}
00
=
[0, 1]
C(X)
B.
Proof. Combine Example 32, Proposition 28 and Theorem 35.
The previous allows us to answer Problem 20 of [18] for the special case of normal SEAs.
Corollary 37. Any element a of a normal SEA E has a unique square root.
Proof.
Note that
a {a}
00
. There is an idempotent
p {a}
00
such that
p ◦{a}
00
contains only
idempotents and
p
◦{a}
00
=
[0
,
1]
C(X)
for some extremally-disconnected compact Hausdorff space
X
.
Write
a
i
:=
p a
and
a
c
:=
p
a
. Then there is a unique
b p
◦{a}
00
with
b
2
=
a
c
(because this
is true in
C
(
X
)). Define
a
:=
a
i
> b
. As
a
i
is idempotent, it is easy to see that
a
2
=
a
and that
in fact
a is the unique such element within {a}
00
.
To prove uniqueness, assume
c
2
=
a
for some
c E
. As
{c}
00
is a sub-algebra of mutually
commuting elements we have
a
=
c
2
{c}
00
and hence
a | c
. As
a {a}
00
, we must then
also have
c |
a
. Consider
B
:=
{
a, a, c}
00
. Reasoning as before,
a
has a unique root in
B
,
hence c =
a.
Note that if a SEA is not normal, it does not need to have unique square roots [50].
2.3 An interesting sequential effect algebra
Before we continue, let us construct a concrete example of a sequential effect algebra that is not
directed complete, in order to serve as a foil of some of the other properties we will prove later.
First, the following is a construction for effect monoids.
Example 38.
Let
V
be an ordered vector space. Let
R
be the space of linear functions
f
:
V V
.
For
f, g R
we set
f g
when
f
(
v
)
g
(
v
) for all
v
0 in
V
. This makes
R
into an ordered vector
space. The set
M
:= [0
, id
]
R
:=
{f R
; 0
f id}
f > g
:=
f
+
g
that is defined when
f id g
is a convex effect algebra [
25
]. Furthermore, defining a product via
composition,
f · g
:=
f g
, makes it an effect monoid. Indeed, this product obviously distributes
over the addition and has id as the identity. That 0 f · g id follows because for all v V
+
we
have 0 f(g(v)) f(v) v = id(v), since 0 g(v), f(v) v = id(v) by assumption.
We can use this construction to construct a specific effect monoid that also happens to be a
non-commutative sequential effect algebra.
Example 39.
Consider
V
:=
R
2
with the positive cone defined by (
a, b
)
>
0 iff
a
+
b >
0. Let
R
and
M
be defined as in Example 38. Of course
R
is just the space of 2
×
2 real matrices. With
some straightforward calculation it can then be verified that
A =
a b
c d
M A = 0 or A = id or 1 > a + c = b + d > 0.
Define a map
τ
:
M
[0
,
1] by
τ
(
a b
c d
) =
a
+
c
=
b
+
d
. Then it is straightforward to check
that
τ
is monotone (
A B
=
τ
(
A
)
τ
(
B
)), multiplicative (
τ
(
A · B
) =
τ
(
A
)
τ
(
B
)), and
A
= 0
iff
τ
(
A
) = 0. As a result
A · B
= 0 iff
A
= 0 or
B
= 0. Hence
M
satisfies
A · B
= 0 iff
B · A
= 0,
making M a SEA.
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This example is interesting because of how close its structure is to that of a SEA coming from
a C
-algebra while still being different in crucial ways. First of all, it is convex and it contains no
non-zero infinitesimal elements: if nA M for all n, then A
= 0
. As far as we are aware, this
is the first example of a non-commutative convex SEA without infinitesimal elements that is not
somehow related to examples from quantum theory. It might hence serve as a counter-example to
reasonable sounding hypotheses or characterisations of (convex) SEAs.
Remark 40.
An effect algebra that does not contain infinitesimal elements is often called
Archimedean. For a convex effect algebra
E
=
[0
,
1]
V
there is however also a stronger notion
that is referred to as being Archimedean. Namely, that for any element of the corresponding vector
space
a V
, if
na
1 for all
n N
then
a
0. We will refer to a convex effect algebra that
has this property as strongly Archimedean. Having no non-zero infinitesimals is equivalent to the
order unit semi-norm
kak
:=
inf{λ R
;
λ
1
a λ
1
}
being a norm, while being strongly
Archimedean also requires the positive cone of V to be closed in this norm.
Coming back to Example 39, let W denote the space spanned by M in R. Then W is a (non-
Archimedean) ordered vector space where its order-unit semi-norm is in fact a norm. This norm
satisfies kAk
:=
inf{λ R
>0
;
λid A λid}
=
|τ
(
A
)
| and as a consequence we see that
the sequential product is continuous in this norm. This is significant because in Ref. [55] it was
shown that a convex finite-dimensional strongly Archimedean SEA where the sequential product
is continuous in the norm must be order-isomorphic to the unit interval of a Euclidean Jordan
algebra, a type of structure closely related to C
-algebras, and hence quantum theory. It was
already noted in [55] that this result does not hold if the SEA contains infinitesimal elements, but
it was left open whether the stronger notion of being Archimedean was necessary, or if having no
non-zero infinitesimals was sufficient. As Example 39 is not order-isomorphic to the unit interval
of a Euclidean Jordan algebra we indeed see that the mere absence of infinitesimal elements does
not suffice for the result.
Example 39 has some further noteworthy properties. Its product is non-commutative, but
unlike the standard sequential product on for instance a C
-algebra, is also associative. Finally, it
is ‘close’ to being directed complete, in the sense that any non-empty directed set S has a minimal
upper bound, but, unless
W
τ
(
S
) = 1
, such upper bounds are not unique, and hence S does not
have a supremum.
3 Boolean sequential effect algebras
Naming sequential effect algebras where every element is idempotent ‘Boolean’ of course suggests
that such an effect algebra must actually be a Boolean algebra. This is indeed the case, and as far
as we know has not been observed before. Let us therefore prove this before we continue on to our
main results. Note that these results are a strict generalization of those in Ref. [52].
Lemma 41.
Let
a
and
b
be elements of a SEA such that
a b
is idempotent. Then
a b b
.
Moreover, if a b
is idempotent too, then a b = b a.
Proof.
Since
a b a
, and
a b
is an idempotent, we have
a b | a
and
a b
= (
a b
)
a
, by point 4
of Proposition 17. Then, using S4, we see that
a b
= (
a b
)
(
a b
) = ((
a b
)
a
)
b
= (
a b
)
b
,
and so a b b, by point 4 of Proposition 17.
Now suppose that
a b
is an idempotent too. Since then
a b
b
, we have
b
(
a b
) = 0,
and so
b
(
a b
) =
b a
. On the other hand,
a b
=
b
(
a b
), because
a b b
, so altogether we
get a b = b (a b) = b a.
Corollary 42. A Boolean idempotent of a SEA is central.
Proof.
Let
E
be a SEA and let
a E
be a Boolean idempotent
a
. Then
a
commutes with
every
b E
by Lemma 41, because
a b
and
a b
are idempotents, on account of being below the
Boolean idempotent a.
Proposition 43.
Let
p
and
q
be idempotents of a SEA
E
. Then
p q
is an idempotent if and only
if p and q commute. Moreover, in that case p q is the infimum of p and q in E.
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Proof. If p and q commute, then it is straightforward to show that (p q)
2
= p q.
Now for the other direction, suppose
p q
is idempotent. Then
p q
is idempotent too, and
so p and q commute, by Lemma 41.
Finally, we must show that
p q
is the infimum of
p
and
q
in
E
. By Lemma 41 we know that
p q
is a lower bound of
p
and
q
. To show that
p q
is the greatest lower bound, let
r p, q
be given.
Since
p
and
q
are idempotents, we have
r p
=
r
=
r q
and
r | p
, so
r
(
p q
) = (
r p
)
q
=
r q
=
r
.
It follows that r p q, and so we conclude that indeed p q = p q.
Recall that a SEA is Boolean when every element is idempotent.
Proposition 44.
Let
E
be a Boolean SEA. Then
E
is a Boolean algebra. Furthermore, for all
a, b E, a b = a b. If E is normal, then E is complete as a Boolean algebra.
Proof.
Let
a, b E
. As
a
,
b
and
a b
are idempotent by assumption, by the previous proposition
they commute and
a b
=
a b
. We conclude that
E
is commutative, and hence it is a (directed-
complete) Boolean effect monoid. Ref. [
59
, Proposition 47] then shows that it is a (complete)
Boolean algebra.
Using our later results it will turn out that any SEA containing only a finite number of elements
must be a Boolean algebra (see Corollary 60).
4 Almost-convex sequential effect algebras
In this section we study what we call almost-convex SEAs (abbreviated to a-convex). We do this
because they naturally arise in a structure theorem for normal SEAs that we prove at the end of
this section.
The content of this section is rather technical, with items 4955 serving as preparation for the
main results: Theorem 57 that characterises convex normal SEAs among a-convex normal SEAs
in several different ways, and Theorems 58 and 59 that together show that any normal SEA splits
up into a direct sum of a Boolean algebra and an a-convex effect algebra.
In the next section we will show that an a-convex normal SEA factors into a convex normal
SEA and a ‘purely a-convex’ normal SEA (Proposition 62).
Definition 45.
An
a-convex action
(almost-convex action) on an effect algebra
E
is a map
·
: [0
,
1]
× E E
, where [0
,
1] is the standard real unit interval, satisfying the following axioms for
all a, b E and λ, µ [0, 1]:
λ · (µ · a) = (λµ) · a.
If λ + µ 1, then λ · a µ · a and λ · a > µ · a = (λ + µ) · a.
1 · a = a.
An
a-convex effect algebra
is an effect algebra
E
endowed with such an a-convex action. When
we say that an effect algebra
E
is a-convex we mean that there’s at least one a-convex action on
E
(but note that in general, there might be more then one a-convex action on a given effect algebra.)
Remark 46.
Recall from Definition 8 that a convex action on an effect algebra is an a-convex
action that in addition satisfies the requirement that for all summable a and b, and λ [0, 1]
λ · (a > b) = λ · a > λ · b.
The definition of a-convexity is strictly weaker then that of convexity. Before we demonstrate
this with an explicit example, we first recall the following method for constructing new (sequential)
effect algebras by taking the ‘disjoint union’ of effect algebras:
Definition 47.
Let
I
be some indexing set, and let
E
α
be an effect algebra for each
α I
. The
horizontal sum
[
13
] of the
E
α
is then defined as
HS
(
E
α
, I
) :=
αI
E
α
/
, the disjoint union
modulo the identification of all the zeros and and all the ones. Explicitly, denoting an element of
αI
E
α
by (
a, α
) where
α I
and
a E
α
we set (
a, α
)
(
b, β
) iff
a
=
b
= 1 or
a
=
b
= 0 or
a
=
b
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and
α
=
β
. We define the complement as (
a, α
)
= (
a
, α
). The summability relation is defined
as follows. For elements (
a, α
) and (
b, β
) we set (
a, α
)
(
b, β
) iff
α
=
β
and
a b
, or if
a
= 0 or
b
= 0. The sum (
a, α
)
>
(
b, β
) for summable elements (
a, α
) and (
b, β
) is defined by case distinction
as follows. If
a
= 0, then (
a, α
)
>
(
b, β
) = (
b, β
). If
b
= 0, then (
a, α
)
>
(
b, β
) = (
a, α
). If
a 6
= 0 and
b 6
= 0 then necessarily
α
=
β
for summable elements and we set (
a, α
)
>
(
b, α
) = (
a > b, α
). This
complement, summability relation, and addition makes the horizontal sum an effect algebra.
This definition might look a bit arbitrary, but note that the horizontal sum of two effect
algebras is in fact the coproduct in the category of effect algebras with unital morphisms [33].
The horizontal sum of two sequential effect algebras does not have to again be a sequential effect
algebra. Necessary and sufficient conditions were found in Ref. [20, Theorem 8.2] for a horizontal
sum of sequential effect algebras to allow a sequential product. Let us give a simple example of
such a SEA coming from a horizontal sum.
Example 48.
Let
H
be the horizontal sum of the unit interval with itself. I.e.
H
is the disjoint
union of the unit interval with itself, that we will call the left [0
,
1]
L
and the right [0
,
1]
R
interval,
where 0
L
= 0
R
and 1
L
= 1
R
are identified. This is an effect algebra where addition is only
defined when elements are both from the left respectively the right interval, and the complement is
λ
L
= (1
λ
)
L
(same for right). It is easy to see that this effect algebra is directed complete (as
each of the unit intervals is). It is also a normal SEA with the product
λ
A
µ
B
= (
λµ
)
A
where
A, B {L, R}
. We can give
H
two different a-convex structures, determined by either setting
λ ·
1 =
λ
L
or
λ ·
1 =
λ
R
. For every other element there is a unique choice given by
λ ·µ
A
= (
λµ
)
A
for
A {L, R}
. It is straightforward to check that either choice for
λ ·
1 gives an a-convex action on
H
.
This however does not make
H
a convex effect algebra, because (supposing without loss of generality
that λ · 1 = λ
L
) we get λ · (
1
2
R
>
1
2
R
) = λ · 1 = λ
L
, while λ ·
1
2
R
> λ ·
1
2
R
= (λ
1
2
)
R
> (λ
1
2
)
R
= λ
R
.
On a normal SEA E an a-convex action yields an additive map ϕ :
[0
,
1]
E given by ϕ
(
λ
) =
λ ·
1
.
We will prove its converse, but that will require some preparation.
Recall that a normal SEA also has infima of decreasing sequences (Remark 14).
Definition 49. Let E be a normal SEA. For a E we define its floor to be bac :=
V
n
a
n
.
Lemma 50.
Let
E
be a normal SEA. For
a E
, we have
bac a
. Furthermore,
bac
is the largest
idempotent below a.
Proof.
To start, since
a
commutes with each
a
n
, we have
a | bac
=
V
n
a
n
, and
baca
=
a ◦bac
=
V
n
a a
n
=
V
n
a
n+1
=
V
n
a
n
=
bac
. Then
baca
n
=
bac
for all
n
, and so
bac
2
=
V
n
baca
n
=
bac
.
Hence bac is an idempotent.
Let
p
be an idempotent below
a
; we must show that
p bac
. Since
p a
, we have
p a
=
a p
=
p
. Note that
p a
2
=
p
(
a a
) = (
p a
)
a
=
p a
=
p
, using here that
a | p
. By a similar
reasoning we get p a
n
= p for all n. Thus p ◦bac =
V
n
p a
n
= p, and so p bac.
Lemma 51.
Given an element
a
of a normal SEA
E
with
bac
= 0 and
n N
>0
, there is a
unique a
0
E with a = na
0
. Moreover, a
0
{a}
00
.
Proof.
Concerning uniqueness, suppose for now that there is an
a
0
{a}
00
with
na
0
=
a
, and
let
b E
with
a
=
nb
be given. Since
b | nb
=
a
, we have
b {a}
0
, and thus
b | a
0
, using here
that
a
0
{a}
00
. It follows that
b
and
a
0
are both part of the commutative normal SEA
{b, a
0
}
00
.
Now, the representation theory for directed-complete effect monoids (cf. Section 2.2.1) gives us that
nb
=
na
0
implies
b
=
a
0
(indeed, this implication holds for commutative
C
-algebras, and trivially
for Boolean algebras). Hence, a
0
is unique.
For the existence of
a
0
{a}
00
we can assume without loss of generality that
E
=
{a}
00
, and,
moreover, that
E
=
B C
for some complete Boolean algebra
B
, and some convex normal effect
monoid
C
, again by the representation theory for directed-complete effect monoids. Then
a
= (
b, c
)
for some
b B
and
c C
. We claim that
b
= 0. For this, note that
b
must be an idempotent
since
B
is Boolean, and so
bbc
=
b
. Since 0 =
bac
=
b
(
b, c
)
c
= (
bbc, bcc
) = (
b, bcc
), we have
b
= 0.
Finally, define a
0
:= (0,
1
n
· c), using here that C is convex, and observe that na
0
= a.
Note that the condition bac
= 0
is necessary in the previous Lemma. Indeed, in Example 48
taking a = 1, we get 2(
1
2
L
) = a = 2(
1
2
R
) while
1
2
L
6=
1
2
R
.
Accepted in Quantum 2020-12-22, click title to verify. Published under CC-BY 4.0. 12
Proposition 52. Let ϕ: [0, 1] E be an additive map into a normal SEA E.
1. ϕ is normal: we have ϕ(
W
D) =
W
λD
ϕ(λ) for every directed subset D of [0, 1].
2. ϕ(λ) | ϕ(µ) for all λ, µ [0, 1].
3. bϕ(λ)c = 0 for any λ [0, 1).
4. If ϕ(λ) = ψ(λ) for some λ (0, 1) and additive ψ : [0, 1] E, then ϕ = ψ.
Proof.
1. Since
W
λD
ϕ
(
λ
)
ϕ
(
W
D
) the difference
ϕ
(
W
D
)
W
λD
ϕ
(
λ
) exists; we must show
that it is zero. Let a natural number n > 0 be given, and pick µ D with
W
D µ
1
n
. Since
ϕ(
W
D)
W
λD
ϕ(λ) ϕ(
W
D) ϕ(µ) = ϕ(
W
D µ) ϕ(
1
n
),
using that
ϕ
(
µ
)
W
λD
ϕ
(
λ
) in the first inequality, we see then that
ϕ
(
W
D
)
W
λD
ϕ
(
λ
) has an
n-fold sum for all n, and hence must therefore be zero by Lemma 21.
2. Let
n, m >
0 be natural numbers. Since
ϕ
(
1
nm
) commutes with itself, it commutes with
(
1
nm
) =
ϕ
(
1
m
) by S5. But then
(
1
nm
) =
ϕ
(
1
n
) commutes with
ϕ
(
1
m
) too, again by S5. Going
on like this we see that
ϕ
(
k
n
)
| ϕ
(
m
) for all natural numbers
k n
and
m
. Whence
ϕ
(
q
)
| ϕ
(
r
)
for all rational
q, r
[0
,
1]. Now let
x, y
[0
,
1] be arbitrary, and pick directed sets
C, D
[0
,
1]
of rational numbers with
W
C
=
x
and
W
D
=
y
. Then
ϕ
(
c
)
| ϕ
(
d
) for all
c C
and
d D
,
and so
ϕ
(
x
) =
W
cC
ϕ
(
c
)
| ϕ
(
d
) for all
d D
, by S6, and the fact that
ϕ
is normal. But
then ϕ(x) |
W
dD
ϕ(d) = ϕ(y) too.
3. Pick a natural number
n >
0 with
λ
1
1
n
. Then
bϕ
(
λ
)
c bϕ
(1
1
n
)
c
and so it suffices to
show that
bϕ
(1
1
n
)
c
= 0. To this end let
p
be an idempotent with
p ϕ
(1
1
n
). We have to show
that
p
= 0. Since
p ϕ
(1
1
n
) =
ϕ
(1)
ϕ
(
1
n
)
1
ϕ
(
1
n
), and so
ϕ
(
1
n
)
p
, we have
ϕ
(1) =
(
1
n
)
p
by Lemma 18, and whence
p ϕ
(1)
. On the other hand
p ϕ
(1
1
n
)
ϕ
(1), so
p
, being below both
ϕ
(1) and
ϕ
(1)
, is summable with itself. Since
p
is an idempotent, we get
p > p p by Lemma 18, and so p = 0, as desired.
4. Since
ϕ
(
λ
) =
ψ
(
λ
), we have
ϕ
(
λ
n
) =
ψ
(
λ
n
) for all natural numbers
n >
0, by Lemma 51, using
here that
bϕ
(
λ
)
c
=
bψ
(
λ
)
c
= 0 by point 3. Since numbers of the form
n
lie dense in [0
,
1], point 1
entails that ϕ = ψ.
Definition 53. Let E be an effect algebra. We call an element h E a half when h > h = 1.
Proposition 54. Let E be a normal SEA. A half is central iff it is unique.
Proof. Given elements h and g of E with h > h = 1 = g > g, and h g = g h, we have
h = h 1 = h (g > g) = h g > h g = g h > g h = g (h > h) = g,
so commuting halves are equal. In particular, a half is unique when it is central.
For the converse, suppose that
h
is the only half in
E
, and let
a
be an element of
E
. We must
show that
a
and
h
commute. To this end, note that
a h > a
h
is a half, and so
h
=
a h > a
h
,
by uniqueness of
h
. Since
a h
commutes with
a h > a h
=
a
, and, similarly,
a
h
commutes
with
a
, and thus with
a
too, we see that
a
commutes with
a h > a
h
=
h
. Whence
h
is
central.
Proposition 55.
Let
E
be a normal SEA. Any unital, additive map
ϕ:
[0
,
1]
E
gives an a-convex
action
·
ϕ
on
E
via
λ ·
ϕ
a
=
a ϕ
(
λ
). Moreover, for an a-convex action
·
, an a-convex action
·
is of
this form iff λ · a = a (λ · 1) for all a E and λ [0, 1].
Proof.
(
·
ϕ
is an a-convex action) Clearly 1
·
ϕ
a
=
a
and (
λ
+
µ
)
·
ϕ
a
=
λ·
ϕ
a> µ·
ϕ
a
for
λ
+
µ
1 and
a
E
. The only difficulty here is in establishing the last remaining condition, that
µ·
ϕ
(
λ·
ϕ
a
) = (
µλ
)
·
ϕ
a
given
µ, λ
[0
,
1] and
a E
. Since for fixed
λ
and
a
both
µ 7→ µ ·
ϕ
(
λ ·
ϕ
a
) and
µ 7→
(
µλ
)
·
ϕ
a
give
,
1]
E
, it suffices by point 4 of Proposition 52 to show that
1
2
·
ϕ
(
λ·
ϕ
a
) = (
1
2
λ
)
·
ϕ
a
.
For
λ
= 1, this is obvious enough, and for
λ <
1 this follows immediately from the fact that
λ ·
ϕ
a
has a unique half by Lemma 51, because
bλ ·
ϕ
ac
= 0 by point 3 of Proposition 52. Note that we
could not prove
1
2
·
ϕ
(
λ ·
ϕ
a
) = (
1
2
λ
)
·
ϕ
a
here by simply applying point 4 of Proposition 52 again as
it’s a priori not clear that λ 7→
1
2
·
ϕ
(λ ·
ϕ
Accepted in Quantum 2020-12-22, click title to verify. Published under CC-BY 4.0. 13
(The condition
λ · a
=
a
(
λ ·
1)) Note that
a
(
λ ·
ϕ
1) =
a
(1
ϕ
(
λ
)) =
a ϕ
(
λ
) =
λ ·
ϕ
a
for
ϕ
. Conversely, for an a-convex action
·
with
λ · a
=
a
(
λ ·
1) for all
λ
[0
,
1]
and a E, we immediately get · = ·
ϕ
where ϕ(λ) = λ · 1.
One might think that the process of constructing an a-convex action from a unital additive map,
and retrieving a unital additive map from an a-convex action are each others inverse, i.e. that we
always have the condition λ · a
=
a
(
λ ·
1)
stated in the proposition above. Example 56 below
shows that this is not the case. For convex actions, however, the equation λ·a
=
a
(
λ·
1)
does hold
(because there is only one a-convex action in the presence of a convex action, see Theorem 57).
Example 56.
Let
H
=
HS
([0
,
1]
,
[0
,
1]) be the horizontal sum of [0
,
1] with itself from Example 48,
equipped with the a-convex action determined by
λ ·
1 =
λ
L
. Now let
E
=
HS
(
H H,
[0
,
1]),
the horizontal sum of
H H
and [0
,
1]. We define a sequential product by case distinction: Let
(
a, b
)
,
(
a
0
, b
0
)
H H
and take
µ, µ
0
[0
,
1]. We set
µ µ
0
=
µµ
0
and
µ
(
a, b
) =
1
2
(
µa
+
µb
), where
we interpret
a
and
b
as elements of [0
,
1]. We set (
a, b
)
(
a
0
, b
0
) = (
a a
0
, b b
0
) and (
a, b
)
µ
=
(a µ
R
, b µ
R
) where we interpret µ as µ
R
in H. So in particular (1, 0) µ = (µ
R
, 0).
Now we equip
E
with an a-convex action. For (
a, b
)
H H
with (
a, b
)
6
= (1
,
1) we set
λ ·
(
a, b
) = (
λ · a, λ · b
), and for
µ
[0
,
1] with
µ 6
= 1 we set
λ · µ
=
λµ
. Finally, for 1
E
we
set
λ ·
1 =
λ
R
, i.e. an element of [0
,
1]. We now see that
λ ·
(1
,
0) = (
λ ·
1
,
0) = (
λ
L
,
0), while
(1, 0) (λ · 1) = (1, 0) λ = (1 λ
R
, 0) = (λ
R
, 0).
Theorem 57. For a normal SEA E the following are equivalent.
1. There is a convex action on E.
2. There is precisely one a-convex action on E.
3. There is a central h E with h > h = 1.
4. There is precisely one h E with h > h = 1.
5. For each a E there is precisely one b E with b > b = a.
6.
There is an a-convex action on
E
, and any such a-convex action
·
can be restricted to
Z
(
E
)
in the sense that λ · a is central for all λ [0, 1] and a Z(E).
7. Z(E) is convex.
Moreover, in that case
λ · a
=
a
(
λ ·
1) for the unique a-convex action
·
on
E
, and all
a E
and λ [0, 1].
Proof.
We begin by proving that 15 are equivalent by producing the loop of implications
143521. Along the way, we establish 24 as it is needed to prove 21.
(1
4) Let
·
be a convex action on
E
. Then 1 has a unique half: if
h > h
= 1 for some
h E
,
then h = (
1
2
>
1
2
) · h =
1
2
· h >
1
2
· h =
1
2
· (h > h) =
1
2
· 1.
(43) Follows immediately from Proposition 54.
(3
5) Let
a E
be given; we must show that
a
has a unique half. Let
h
be a central element
such that
h > h
= 1. Since
b
=
b
(
h > h
) = (
b h
)
>
(
b h
) = (
h b
)
>
(
h b
) =
h
(
b > b
) =
h a
for any b E with a = b > b, we see that a has a unique half.
(5
2) Assume each
a E
has a unique half. For uniqueness, let
·
1
and
·
2
be a-convex actions
on
E
. To prove that
·
1
=
·
2
, we must show that (
·
)
·
1
a
= (
·
)
·
2
a
for given
a E
, and for this it
suffices to show that
1
2
·
1
a
=
1
2
·
2
a
, by Proposition 52.4. But since both
1
2
·
1
a
and
1
2
·
2
a
are halves
of a, this follows by assumption.
It remains to be shown that there is at least one a-convex action on
E
. To this end, let
h
be a
half of 1, and note that
{h}
00
being a directed-complete effect monoid with a half is isomorphic
to [0
,
1]
C(X)
for some extremally-disconnected compact Hausdorff space
X
, via some isomorphism
Φ
:
[0
,
1]
C(X)
{h}
00
. The assignment
λ 7→
Φ(
λ
), where is the function on
X
that is constant one,
ϕ:
[0
,
1]
E
, and so
E
has a a-convex action given by
λ · a
=
a ϕ
(
λ
)
by Proposition 55.
(2
4) Suppose that
E
has a unique a-convex action
·
. Then clearly 1 has a half given by
1
2
·
1.
Concerning uniqueness, let
h E
with
h > h
= 1 be given. Considering the directed-complete
Accepted in Quantum 2020-12-22, click title to verify. Published under CC-BY 4.0. 14
effect monoid
{h}
00
we can find a unital, additive map
ϕ:
[0
,
1]
E
with
ϕ
(
1
2
) =
h
, which yields
an a-convex action
·
ϕ
on
E
given by
λ ·
ϕ
a
=
a ϕ
(
λ
) by Proposition 55. Since there is only one
a-convex action on E, we get · = ·
ϕ
, and thus
1
2
· 1 =
1
2
·
ϕ
1 = ϕ(
1
2
) = h.
(2
1) Let
·
be the unique a-convex action on
E
. Given summable
a, b E
we must show that
λ · a > λ · b
=
λ ·
(
a > b
) for all
λ
[0
,
1]. Note that by Proposition 52.4 it suffices to show that
1
2
·a >
1
2
·b
=
1
2
·
(
a > b
). Since both sides of this equation are clearly halves of
a > b
, we are done if
halves are unique—which indeed they are, since we have already established that 2435.
Whence 1, 2, 3, 4, and 5 are equivalent. We continue by showing that 6 is equivalent to 15.
(6
3) Let
·
be an a-convex action on
E
. Then, clearly,
h
:=
1
2
·
1 is a central element that
obeys h > h = 1.
(15
6) Let
·
be the unique a-convex action on
E
from 2. We must show that
·
can be restricted
to
Z
(
E
). Since
λ ·
0
a
=
a
(
λ · a
) defines an a-convex action
·
0
on
E
, and
·
is unique, we have
·
=
·
0
,
and so
λ
|
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|
https://www.jiskha.com/display.cgi?id=1330560477
|
# chemistry
posted by .
A
What mass of KCl is needed to precipitate the silver ions from 26.0 mL of 0.100 M AgNO3 solution?
• chemistry -
KCl + AgNO3 ==> AgCl + KNO3
mols AgNO3 = M x L = ?
moles KCl = moles AgNO3 from the 1:1 ratio in the equation.
g KCl = moles KCl x molar mass KCl.
• chemistry -
32.2
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|
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|
http://mathhelpforum.com/differential-geometry/195285-riemann-summ-limit-proof-strange-question-me-print.html
|
# Riemann Summ Limit Proof (strange question to me)
Recall the definition of teh Riemann Sum $S(f;\pi ;\xi)$ for a function $f:[0,1]\rightarrow \mathbb{R}$.
Let $f:[0,1]\rightarrow \mathbb{R},\ x\rightarrow \frac{5}{6}x$[/latex] For the partition $\pi_n$ of $[0,1], 0=t_0 and $\xi_j =\ \frac{2}{3}t_j\ +\ \frac{1}{3}t_(j+1)\in [t_j,t_(j+1)]$ find $S(f;\pi_n,\xi)$.
Now Prove $lim(n\rightarrow infinity)\ of\ S(f;\pi_n,\xi)=\frac{5}{12}$
|
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|
http://www.neuralsystemsandcircuits.com/content/2/1/7
|
# A new measure based on degree distribution that links information theory and network graph analysis
Michael W Hadley1, Matt F McGranaghan1, Aaron Willey2, Chun Wai Liew2 and Elaine R Reynolds1*
Author Affiliations
1 Neuroscience Program, Lafayette College, Easton, PA 18042, USA
2 Department of Computer Science, Lafayette College, Easton, PA 18042, USA
For all author emails, please log on.
Neural Systems & Circuits 2012, 2:7 doi:10.1186/2042-1001-2-7
Received: 22 June 2011 Accepted: 28 May 2012 Published: 24 June 2012
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
### Abstract
#### Background
Detailed connection maps of human and nonhuman brains are being generated with new technologies, and graph metrics have been instrumental in understanding the general organizational features of these structures. Neural networks appear to have small world properties: they have clustered regions, while maintaining integrative features such as short average pathlengths.
#### Results
We captured the structural characteristics of clustered networks with short average pathlengths through our own variable, System Difference (SD), which is computationally simple and calculable for larger graph systems. SD is a Jaccardian measure generated by averaging all of the differences in the connection patterns between any two nodes of a system. We calculated SD over large random samples of matrices and found that high SD matrices have a low average pathlength and a larger number of clustered structures. SD is a measure of degree distribution with high SD matrices maximizing entropic properties. Phi (Φ), an information theory metric that assesses a system’s capacity to integrate information, correlated well with SD - with SD explaining over 90% of the variance in systems above 11 nodes (tested for 4 to 13 nodes). However, newer versions of Φ do not correlate well with the SD metric.
#### Conclusions
The new network measure, SD, provides a link between high entropic structures and degree distributions as related to small world properties.
##### Keywords:
Degree distribution; Graph theory; Information integration theory; Neural networks; Degree distribution; Small world properties
### Background
The nervous system is an informational system on the grandest scale: complex both in terms of its number of components and its organization. To understand how information is processed within it, physiologists and modelers have traditionally examined the electrical dynamics that directly convey information across the components of the system (that is, firing patterns of neurons or groups of neurons). With advancements in imaging technology, more recent work has focused on the structural properties of networks of neurons (the physical connections between neurons) that underlie these functional dynamics. Several efforts are underway to understand both structural and functional connections of the brain and how that connectivity influences informational flow and capacity. A group of researchers, now collectively part of the Human Connectome Project, has been creating connectivity maps of model and human nervous systems and developing tools to analyze their informational, structural and functional properties [1-5].
The graph theory metrics used in these analyses are based on the general properties of complex networks (that is, nonrandom, nonlattice networks) [6]. Some measures, such as degree, quantify the number of connections or edges between nodes. More complex measures look at patterns of connections: whether all the nodes of the system are closely connected or integrated (for example, path length - the minimum number of edges between nodes); or whether some parts of the graph might have clustered connections or hubs (for example, clustering coefficient - a measure of how related neighbors are in a graph). These metrics not only provide a way of analyzing networks but also lay the groundwork for understanding them. Based on these models, metrics, and physical data of connectivity in the brain, it has been proposed that neurological networks have small world properties, that is they are a collection of interconnected hubs [7-10]. Small world characteristics are found in many real world networks [11].
A different approach to understanding structure-function relationships of neural networks is to use information theory to provide a theoretical framework for identifying structures that integrate information while allowing for the differentiation necessary for a highly complex information capacity [12]. Tononi and collaborators created a metric called Phi (Φ), a measure of the minimum effective information (EI). EI is a directional measure of the causal influences between subsets of a network, and thus the minimum EI reflects a system’s capacity to integrate information [13,14]. The Φ measure, which was updated in 2008 and in 2011, moved the integrated information theory closer to the goal of formalizing a theory of consciousness based on the ability of a system to integrate and process large amounts of information [15-17]. Graphs that have been optimized for high Φ have been proposed to have small world properties suggesting that the structures found within biological neural networks would also have the ability to integrate information. However, this finding needs to be confirmed with the newer derivations of Φ [13]. Much of the literature in this area of complexity and consciousness focuses on a neural network having properties of integration and differentiation that would be apparent at both the structural and functional levels of analysis [18].
It seems then that some common structural characteristics may underlie complex neural networks: the ability of each node to reach any other node (integration or connectedness), and a high degree of node structure variance (specialization or differentiation). Currently there is no direct measure of these properties. The small world properties of a system of nodes are calculated from the ratio of the graph metrics for clustering (a measure of intermodal connectivity) and pathlength (a measure of the average distance between nodes). The ratio is normalized with corresponding values from a ‘random’ system [11]. This measure for small worldness may or may not reflect the properties of connectedness and specialization seen within real world systems. The goal of our work was to capture the characteristics of connectedness and segregation in a new variable that can be used to bridge the graph theory measures and the information theory metrics for larger nodal systems. Our new metric, System Difference (SD), is a Jaccardian measure of difference across a system that reflects the degree distribution of a network. We discuss this new measure in terms of its mathematical properties and its predictive value for structural properties based on other graph metrics, and we compare our new measure to other measures of complexity. When analyzing a population of randomly generated nodes, high SD is predictive of structures that are connected, but maintain some clustering, much like those structures that have small-world properties.
### Results and discussion
#### Development of new variables
We considered a number of options for generating variables that were computationally simple yet captured the properties of specialization and connectedness. Information theory, which uses entropy as a basic means to understand the information flow within a system, was first developed by Shannon in 1948 [19]. The application of this theory to networks formalizes that idea that a system’s entropy quantifies the number of possible states available to the system. So we were looking for a metric that measured specialization and connectedness, but also took into account that systems with an intermediate density of connections were likely to be the most complex in terms of information states. We generated random networks and examined the graph properties of various metrics. We tested density, variables based on cycles, number of reciprocal connections, and several modularity measures derived from the igraph and other sources [18,19]. Two newly defined measures best captured the features of connectedness and specialization: Average Connectedness (AC) and SD.
In analyzing networks, we can represent the network as a graph with circles representing nodes (or neurons in the case of the nervous system) and arrows representing directed edges or connections (Figure 1A). It is easier to work computationally with a network system represented as a matrix, A, where a nonzero entry indicates a connection and where the columns represent inputs and the rows represent outputs (Figure 1B). Our variable capturing connectedness, (AC), was defined as the ability of a node to communicate information, either directly or through a series of nodes, to any other node in the network (See Figure 1C for a sample calculation). AC is the average reachability of a system. To implement this computationally, we created a matrix, R, of reachabilities (using the transitive definition) where a zero in position Ri,j indicates that node j is not reachable from node i and a one in position Ri,j indicates that node j is reachable from node i. AC is the sum of the elements in the matrix divided by n2[20].
Figure 1 . Calculations of System Difference and Average Connectedness in a graph. A) Representation of a directed, binary system in graph form. (B) The same system's corresponding connection matrix where rows represent outputs and columns represent inputs. A nonzero value in Ai,j indicates the presence of a connection from node i to node j, and a value of zero indicates no connection. (C) Illustration of the concept of reachability. A node is reachable from another node if a path can be found between them. Node 4 can reach node 2 by passing through node 1. Node 2 cannot reach node 4. Average Connectedness is the average node reachability of the graph (that is, the number of pairs of nodes A and B - such that B is reachable from A - divided by the number of nodes). (D) The central calculation of System Difference (SD): non-overlap. When comparing the output structure of node 1 to that of node 3, we must define sets representing each node’s outputs. Those sets can then be compared to find the number of different entries (or non-overlap) between them. SD is the average non-overlap for all combinations of two nodes in the graph.
Our variable capturing specialization, (SD), quantifies the average difference in connection patterns between any two nodes of a network (see Figure 1D for a sample calculation). We represent each node’s inputs and outputs as sets and apply a variant of Jaccardian distance to count the non-overlap in the input and output sets between pairs of nodes. SD is the average non-overlap in input structure plus the average non-overlap in output structure.
Comparisons were made between the new measures, AC and SD, using a small, randomly generated sample of weakly connected, directed matrices of 4 to 13 nodes. In generating these matrices, the probability of a connection was 0.5, and there were no self-loops (Ai,i = 0). Isomorphs and non-weakly connected systems were excluded (see Methods). A weakly connected, directed graph is a graph in which each node can reach all other nodes if you were to treat directed connections as bidirectional or undirected. Based on regression analysis at seven nodes, AC and SD were highly correlated with each other - AC accounted for over 80% of the variance in SD. Given the correlation between these variables, we continued forward with the SD metric.
SD was formulated to measure specialization in particular by quantifying the differences in connection structure between the nodes in an unweighted, directed graph. One might expect that two neurons that perform similar functions are more likely to be connected to similar sets of neurons and likewise, two neurons performing divergent functions are less likely to be connected to similar sets of neurons. A simple way to capture this dissimilarity of sets is through Jaccard Distance. Jaccard Distance (shown in Equation 1) is the percentage of distinct elements that are not shared between two sets [21]:
(1)
The numerator of the Jaccard Distance from Equation 2 calculates the number of distinct elements (the non-overlap) in the sets A and B:
(2)
Since SD is a measure of the average non-overlap between nodes in a system, it can be derived through repeated application of Equation 2 to sets that represent the connections in a graph. These sets can be quantified as:
SD is the average difference (or non-overlap) in the sets and can be formalized as:
(3)
The non-overlap of the sets representing outputs and inputs is obtained by summing the non-overlaps over all distinct pairs of nodes in the graph. In order to obtain an average difference, the number of non-overlap must be divided by the number of distinct comparisons. There are n/2 comparisons where n is the number of nodes which can be simplified to the denominator in Equation 4. By substituting Equation 2 into the numerator of Equation 3, the final SD formula becomes:
(4)
One advantage of SD is that it is computationally simple. We calculated the computation times for SD with increasing number of nodes from benchmark experiments. SD can be calculated for a 15 node matrix in 0.0001 seconds and for a 1000 node matrix in under a minute. The computationally fast measure SD can be used to assess larger networks and therefore may be a good measure for assessing biologically based networks and other complex nodal systems.
#### Comparisons of System Difference with graph theory metrics
Using a large sample of random, directed networks (24,000 networks with 8 to 11 nodes), we looked at the relationship of SD to a number of graph theory measures. Each matrix, A, (of size n) was generated by creating n columns each randomly filled with c connections where c is a random number from 1 to n-1 inclusive (c was the same for each matrix). Self loops were eliminated by inserting zero on the diagonal. This generation procedure produces matrices that are both normalized and binary (see Methods for further explanation). We used the igraph software package to generate the values of the graph metrics for the sample graphs [22]. SD was plotted against the graph theory measures for density, maximum degree, omega, number of motifs (of sizes three and four), and average path length (each of these measures are defined and discussed below). The relationships between SD and each graph metric for 11 nodes were fitted with a polynomial regression, and the second-degree fits are presented along with the individual data points in Figure 2.
Figure 2 . SD Plotted Against Graph Metrics. Each graph is generated by calculating System Difference and a graph metric in 24,000 random, weakly connected, normalized networks (n = 11). We sampled from graphs with degrees ranging from 1 to n-1, in steps of one such that the normalized graphs would only have one weight value (see Methods: System Difference comparisons with graph theory metrics (Figure 2) and 2003 Phi. Comparisons with Graph Variables'). The lines plotted on the graphs are the best fits for the second-degree polynomials of SD. SD is plotted against A) maximum degree, B) density, C) omega, D) average path length, E) motif number (size three) and F) motif number (size four).
Density and degree are fundamental properties of a system; density is the percentage of connections present in a graph, and degree is the number of edges connected to a node. In Figure 2A and B, we graphed SD against the density and maximum degree of the graph (the maximum of the sum of in- and out-degrees over all nodes). For density and degree, SD shows an upside-down U-shaped relationship. This trend suggests that SD shows entropic properties over degree distribution (high and low degrees yield low SD while median degrees yield high SD). As described above, we would expect that a graph with no connections (all nodes are independent) and a fully connected graph (excessive information communication causing every node to carry the same information) would have less complexity than matrices with an intermediate number of connections (a balance of information communication and distribution of information).
A clique is a subset of nodes in a graph that are fully connected if you replace all the directed edges with bidirectional edges. A maximal clique is a clique that is not contained within a larger clique. In order to get a sense of modularity, we plotted SD against omega (the size of the largest maximal clique) as shown in Figure 2C[22,23]. Specialization and connectedness are reflected in a balance between local, modular structures and more global structures. SD appears to capture this trend -showing omegas of approximately six at maximal SD indicating some modular structure.
Average path length is the average geodesic distance between two nodes in a graph (that is, the average number of edges that must be traversed to travel from one node to another) [22]. Looking at Figure 2D, we can see that SD shows a skewed upside-down U-shaped distribution against average path length. High SD appears to be biased towards low average path length. A low average path length indicates that the system has strong global connections and so the distribution of values for average pathlength suggests that SD might be an integrative measure. Hub or modular structures with shorter pathlengths are characteristics of small-world networks typical of biological systems [9].
Lastly, we looked at the presence of certain structural motif metrics. A structural motif is a weakly connected, directed graph of n nodes that serves as a building block within a larger graph. Weak connectedness requires that a motif have at least n-1 connections, and since self-loops are excluded, a motif can have at most n2-n connections. For each size n, there are a fixed number of unique (non-isomorphic) motif classes. A graph can be analyzed to count the number of times each of the motif classes (of size n) occurs; this metric is called motif number [24,25]. In Figure 2E and F, we plotted SD against motif number for motifs of size three and size four respectively. High SD is correlated with higher number of motifs (the curve shifts to the right), which suggests that SD might be indicative of clustering or hub structures within the larger system.
The data presented here suggest that high SD networks are biased towards shorter pathlengths and higher clustering, structural properties associated with small world properties.
#### System Difference and degree
In all the analyses of SD, we observed a strong relationship with the density or degree of the graph. The U-shaped trend that SD shows against density becomes more pronounced as the number of nodes is increased. In exploring SD’s relationship to degree, we discovered that SD could be expressed in terms of degree distribution.
A graph can be represented with a connectivity matrix - a matrix A where Aij represents the connection from node i to node j. In our unweighted graphs, Aij will have a value of one if node i has an output to node j or Aij will have a value zero if no such output exists. The set theory formulation of SD (Equation 4) can be represented as pairwise comparisons within the connection matrix where:
The difference function D(x, y) simply compares x and y and returns a one if x and y have the same value and a zero otherwise. The non-overlap functions from the numerator of Equation 4 can be substituted with the difference function. The non-overlap in outputs between nodes a and b can be calculated by comparing row a and row b of A, and the non-overlap in inputs can be calculated by comparing column a and column b:
(5)
(6)
This substitution can be used in Equation 4 to arrive at a derivation of SD in terms of A:
(7)
The order of summation in the numerator of Equation 7 can be rearranged to show that the non-overlap of the outputs is a computation that can be performed for each column independently:
(8)
For any given t, the right hand side of Equation 8 represents the non-overlap in column t, which amounts to the number of times that Aa,t and Ab,t are not equal for each combination of a and b. This can be found by multiplying the number of inputs in the column by the number of locations where there is no input. The number of inputs in a column t is the in-degree of node t:
(9)
The number of locations where there is no input can be found by subtracting the in-degree from n (the number of nodes). Then the non-overlap in column t becomes:
(10)
A similar rearrangement shows that non-overlap of the inputs can be found from each row independently. The end formula is the same except with out-degree used instead of in-degree, where out-degree is:
(11)
With substitutions for both the non-overlap in the inputs and in the outputs, the SD calculation can be expressed completely in terms of degree:
(12)
#### System Difference and graph substructure
Our understanding of SD in terms of degree suggests that the substructure of a graph should show certain trends with respect to SD. Recall that cliques are subsets of nodes that are fully connected in an undirected version of the graph, a maximal clique is a clique that is not contained within a larger clique and omega is the size of the largest maximal clique within a graph. For these experiments, a new set of random, directed, and weakly connected matrices were generated that sampled uniformly over density. Random density was generated for each matrix by adding connections one at a time until the random density was reached or just exceeded. Again, isomorphs, self-loops and non-weakly connected systems were excluded (see Methods). When SD, with a graph size of 50, is plotted against omega (or average maximal clique size) the trend is U-shaped; thus, structures with low SD either have a very small omega or very large omega (Figure 3B, C). When SD is plotted against the number of maximal cliques, the trend is more complicated (Figure 3D). Larger numbers of maximal clusters bias networks to higher values of SD, but low numbers of maximal cliques span the whole range of SD values. Structures with maximal SD have clique sizes of about 10 to 15. This means that in these high SD structures there are groups of at least 10 nodes that are interconnected. In the lowest SD structures, either all the nodes form one interconnected group or none of the nodes form a connected subset. The combined results from the individual trends in Figure 3B, C, D suggest that high SD networks tend to have multiple large cliques suggestive of a modular structure.
Figure 3 . System Diffence plotted against density and clique graph metrics. Each graph is generated by calculating System Difference (SD) and a graph metric in 1000 random, weakly connected networks (n = 50) sampled uniformly over density. A random density value was generated for each matrix by adding connections one at a time until the random density was reached or just exceeded. (A) SD plotted against density. (B) SD plotted against omega. (C) SD plotted against average maximal clique. (D) SD plotted against number of maximal cliques.
A closer analysis of SD and motifs also gives us a better understanding of graph substructure. Recall that motifs are structural subunits that can be identified within a graph. The distribution of SD plotted against different motif metrics emphasizes that SD is a measure of degree distribution. Four distinct trends among the 13 different motifs classes are observed when comparing the frequency of the motif structures (of size three) to SD, each of which is related to the density of that group. Group 1 (Figure 4A) contains all motif structures that have either two or four connections (densities of 1/3 or 2/3 respectively, which equally deviate from a density of 0.5). Group 2 (Figure 4B) contains all motif structures that have three connections (density of 0.5). Group 3 (Figure 4C) has the motif with five connections (density of 5/6). Finally, group 4 (Figure 4D) has the motif with six connections (density of 1). High SD structures are saturated in groups 1 and 2 while generally lacking in groups 3 and 4. Low SD structures are generally lacking in groups 1 and 2 and either saturated or deficient in groups 3 and 4.
Figure 4 . System Difference plotted against motifs. Each graph is generated by calculating System Difference (SD) and metric in 1,000 random, weakly connected networks (n = 100) sampled uniformly over density. A random density value was generated for each matrix by adding conncetions one at a time until the random density was reached or just exceeded. (A-D) SD plotted against the number of occurences of different motifs of size three. The number convention comes from igraph [22], so network graphs are displayed for clarity. The plots and network graphs are grouped by the trend observed against SD. (E) SD plotted against the motif number for motifs of size three.
The trend that motifs show is that a density of about 0.5 maximizes SD on a local, motif scale. The entropic properties of SD yield the symmetrical properties observed when comparing over-connected and under-connected structures. The local emphasis on density in specific substructures then results in the motif number trend observed (Figure 4E), which is a slightly skewed version of the trend that overall density shows against SD (Figure 3A). These results suggest that maximum SD is obtained when the in-degree and out-degree for each node are as close to n/2 as possible, and minimum SD is obtained when the degrees are as far from n/2as.
The analysis of SD in terms of substructure can be taken to the extreme of examining the contribution by individual nodes. If we temporarily assume that in-degree and out-degree for each node can be set independently from any other node, we can take the analysis of SD in substructure to the extreme of a single node:
(13)
These results lead to a general strategy for hitting a target SD by either moving in-degrees and/or out-degrees away from or towards n/2. This strategy leads to the insights of the nuances of the global trend of SD and density. Random graphs with a density of 0.5 will likely have a high SD value because in- and out-degree will tend towards n/2. In contrast, a graph with a density near 0.5, but with in-degree and out-degree distributions that differ greatly from n/2 will actually yield a low SD.
In terms of the integrative measure of average path length, SD generally follows a skewed upside-down U-shaped trend with the peak at a path length of 1.5 (Figure 5A). The graph shows a long tail as path length increases because graphs are required to be weakly connected. The section of the curve (to the left side of the peak) represents the matrices with densities of 1 to around 0.5. Networks that are fully connected or near fully connected have path lengths near 1, that is, every node is directly linked to nearly every other node.
Figure 5 . System Difference, density and path length. The graphs are generated by calculating System Difference, density and average path length in 1,000 random, weakly connected networks (n = 50) sampled uniformly over density. A random density value was generated for each matrix by adding connections one at a time until the random density was reached or just exceeded. (A) SD plotted against average path length. (B) Density plotted against average path length.
Density and average path length have a relationship with a critical point (Figure 5B). With densities of 0 to 0.3, adding additional edges results in large, decreasing gains in average path length. From 0.3 to 1, adding edges results in much smaller (but constant) decreases in path length. The critical point is around 0.3 density (which corresponds to a path length of around 1.8) when the critical gaps in network connectivity have all been filled in. Although the maximal SD lands off this critical point, structures around this critical point have high SD, representing a balance between density and path length.
The trends seen between SD and substructure/average path length can be combined. The average path length for the nodes within a clique should approach one since the nodes are interconnected. Since high SD matrices with 50 nodes have maximal cliques around 15, at the very least one third of the nodes are weakly connected, which would likely generously decrease the average path length. The path length would be lowered even more if there were multiple maximal cliques that were linked together.
#### System Difference and other complexity measures
Our original inspiration in defining SD was the measure of complexity originally developed by Tononi and collaborators, Φ (here after referred to as 2003 Φ) [12,13]. 2003 Φ is a measure of the dynamic informational properties of a network; high 2003 Φ strikes a balance between the diversity of information states of a network and the causal dependence between the nodes of the network [13]. 2003 Φ is a measure of the integrative capacity of a set of nodes. The causal interactions are captured by partitioning the set into two subsets, and then the entropy of firing is measured in one subset while the other subset is stimulated with maximal entropy of activity. This information flow over a bipartition, the IE, is modified version of mutual information that takes into account the direction of information flow. The 2003 Φ for a subset of system, S, is defined as the bipartition of S such that EI is minimized. (See Methods2003 Phi.) [13,14].
Several recent papers, however, have called into question the calculation by which the 2003 Φ was derived. EI can be obtained from the covariance matrix of the network, which represents all deviations from independence among the nodes. In solving the linear equation representing the system dynamics, Tononi and colleagues made an assumption that was disputed first by Barnett et al. (2009) [26]. Various corrected versions of Φ have been offered most recently by Barrett and Seth in 2011 [16]. The extended version of Φ proposed by Barrett and Seth (referred to here after as Φ Empirical) calculates information based on an empirical, stationary distribution (see MethodsPhi Empirical). The approach of Barrett and Seth is based on taking the stationary firing of a system and calculating information integration of transitions from one state to another that is separated by some time lag, τ. Φ Empirical (given a particular τ) is the amount of information integration generated by the current state about the state τ time-steps in the past. It can be calculated either by observing a sufficient number of firing states or though an analytical formula [16].
We first assessed the relationship between SD and the 2003 Φ proposed by Tononi and collaborators. The matrices used were the same as those used to generate Figure 2 (24,000 random, directed networks with 8 to 11 nodes). In order to calculate 2003 Φ, all matrices must be normalized according the following equation (where A is the connectivity matrix before normalization and C is the normalized connectivity matrix):
(14)
As stated previously, each matrix A (of size n) was generated by creating n columns each randomly filled with c connections where c is a random number from 1 to n-1 inclusive (c was the same for each graph). We chose k to be 0.5, and thus each the connection weight was 0.5/c. This procedure enforces normalization (such that C = A) while keeping each matrix to only one weight value (in addition to the absence of a weight, that is, zero). SD is calculated by treating the matrix as if it is unweighted and hence, normalization does not change the value of SD. After generating these matrices and the values associated with them, we linearly regressed SD against 2003 Φ. The correlation values for the comparisons were 0.667 (n = 8), 0.804 (n = 9), 0.871 (n = 10), and 0.9140 (n = 11). Using various procedures for generating random networks, we consistently find the same level of correlation and the same trend that correlation increases with increasing number of nodes (data not shown). While the pattern of correlation is consistently strong across multiple experiments, the correlation is based on the general trends of 2003 Φ and SD rather than a point-by-point correspondence. Using the same set of matrices described above, we compared the 2003 Φ with the same graph metrics used in our analysis of SD. The 2003 Φ and SD appear to measure similar structural features of networks (trends in graphs of 2003 Φ plotted against the same graph metrics in Figure 2 closely match the trends SD shows in that figure), with one of the most notable shared features being a U-shaped distribution over density (data not shown).
We also generated random matrices to compare SD, 2003 Φ and Φ Empirical using the same procedure for matrix generation and normalization described above that is, generating matrices such that C = A). We looked at correlations between these three measures and density. 2003 Φ and Φ Empirical differ in their trend over density. While 2003 Φ and SD share the entropic U-shaped distribution over density, Φ Empirical shows a less clear trend and does not correlate well with SD (Figure 6B). It appears that the highest Φ Empirical values are found in very low density networks. Consequentially, Φ Empirical does not correlate well with SD (Figure 6A). While it is clear that the calculation of 2003 Φ is flawed, the characteristics of Φ Empirical need to be further examined to assess whether it captures structural features associated with small world properties or the expectations associated with information theory.
Figure 6 . Phi Empirical. The graphs are generated by calculating Φ Empirical, System Difference and density in 5,000 random, weakly connected, normalized networks (n = 9) sampled uniformly over density such that the normalized graphs would only have one weight value (see Methods, System Difference and Phi Empirical). (A) Φ Empirical plotted against SD. (B) Φ Empirical plotted against density. Φ Empirical has a time lag parameter over which to calculate information integration. The results above are typical for all time lags attempted (one to four as well as the sum of the Φs over multiple time lags).
### Conclusions
Degree distribution has always been recognized as an important aspect of structural characteristics of systems. Different defined types of systems (small world, scale free, modular) have distinctive degree distributions characteristics [3,27]. The neural complexity measure from which the original 2003 Φ was derived is heavily dependent on degree [28]. Many papers in the field define degree distributions as a probability function: the distribution is defined as the probability that a selected node has degree k [19,29]. The degree distribution of a system then represents the cumulative degree distribution as the probability over all nodes. The advantage SD offers over this method is that it specifically defines an entropic degree distribution where over-connected and under-connected distributions yield low SD and median connectivity results in high SD. We have not encountered a graph measure that links entropy and degree distribution.
SD then is a measure of entropic degree distribution and could be used to look for these specific features within graphs. It is possible and likely that a major determinant of neural complexity is degree distribution. It may be that a degree distribution that balances a set of constraints to produce a system that is both segregated and connected has a simple solution n/2, the optimal degree for complexity, as can be seen from our analysis of the graph measures in the context of optimum SD degree distribution. This combination of local and network degree optimums pushes local structures towards cliques, hubs or clusters with particular motif patterns and short path lengths. This makes sense from a biological perspective as well. We know from empirical evidence that the brain is modular and that it probably evolved as a series of subunits that were organized into the massively parallel system. Modules that met local degree optimum were hooked together in such a way as to create optimums at a higher level of the network hierarchy. So it makes sense that we would see this degree distribution at multiple levels of structure. As is so often in nature, the solution is elegant.
### Methods
#### Matrix generation algorithms and experimental analysis
The generation algorithms for each experiment differed slightly. All experiments used directed, weakly connected graphs with no self-loops.
#### Development of the variables Average Connectedness and System Difference (no figure shown)
For each matrix that was generated, each connection had a 50% chance of being assigned a value of 0.5 and a 50% chance of being assigned a value of zero Self-loops, isomorphs and non-weakly connected systems (defined below in the section "Detection") were excluded. We collected datasets for networks of sizes 4 through 13 with sample size from 215 (n = 4) and 1,000 (n = 13). We performed exponential fits of AC on SD for each n using Microsoft Excel.
#### System Difference comparisons with graph theory metrics (Figure 2) and 2003 Phi
We generated a single set of matrices that could be used to make comparisons between SD, 2003 Φ and a set of graph theory matrices. In order to calculate Φ, matrices must be normalized. However, normalization does not affect the calculation of SD, which only takes into account whether nodes are connected or not. The matrices in these trials were generated according to our normalization procedure described in [13] and in more detail below. For each matrix that was generated, the number of weights per column was a random number between 1 and n-1 inclusive. n columns were created with n-1 elements (consisting of ones and zeros in random order). A main diagonal of zeros was inserted to form an n by n matrix with no self-loops. This procedure ensured that each matrix would only have one weight value (in addition to the absence of a weight, that is, zero). We collected datasets for networks of sizes 8 through 11 with a sample size of 24,000 for each n. For each network size, we calculated SD and 2003 Φ for each matrix as well as a selection of graph theory metrics (from igraph) [22]. We performed linear correlation of 2003 Φ on SD using the R statistics package [29]. We plotted SD and the graph theory metrics with second-degree polynomial model fits (Figure 2), and we also compared 2003 Φ to these same metrics (data not shown). Plots were generated in the R package [30]
#### System Difference time benchmarks
Randomly generated matrices for multiple node sizes were sampled. SD was calculated and the time to calculate was averaged over several sample sizes. These experiments were carried out on a set of identical rack mounted computer systems. Each system had two AMD Dual Core Opteron 275 processors with 8 GB of RAM.
#### System Difference and subgraph analysis (Figures 3, 4 and 5)
The matrices in these trials were generated to sample uniformly over density. A random density was generated for each matrix and connections were added one at a time until the random density was reached or exceeded. No normalization was applied. The graph theory metrics were calculated through igraph [22]. For motif metrics, 100-node networks were generated with a sample size of 1,000. For density, omega, average maximal clique size, number of maximal cliques and path length, 50-node networks were generated using a sample size of 1,000. Plots were generated in the R package [30].
#### System Difference and Phi Empirical (Figure 6)
The same matrix generation procedure was used as in the 2003 Φ comparisons with SD. In this case, 5000 nine-node systems were generated and then Φ Empirical, SD and density were calculated. Time lags of one ,two, three and four were used for Φ Empirical. We also calculated the sum of the Φ Empirical values over those time lags (see Φ Empirical below). The output was plotted using the R package [30].
#### Detection
During generation of networks for any experiment, each newly generated network was checked against all previous networks generated in the experiment using the algorithms below. Networks that faiedl to pass the algorithms were discarded and a new random network was generated.
#### Isomorph detection
Two systems are isomorphic if a relabeling of the vertices of one system yields a copy of the other system. Isomorphs were avoided through igraph’s implementation of the VF2 algorithm for isomorph detection [22].
#### Weakly connected
A weakly connected, directed graph is a graph in which each node has an undirected path to each other node. Weak connectivity was checked using igraph’s connectivity detection implementation [22].
#### Self-loop
A loop (or self-loop) is a connection from a vertex onto itself. Loops were excluded by generating (n-1) by n matrices and then inserting a main diagonal of zero to form n by n matrices.
#### Normalization
In calculating Φ, a normalization procedure was used to separate out the effects of weight magnitude from the effects of structure [13]. Their normalization takes a connection matrix A, and generates C, the normalized connectivity matrix:
(17)
In order to preserve this normalization while keeping each matrix to only one weight value (in addition to the absence of a weight, that is, zero), we had to make the sum of the column j the same value for all j. By holding the number of weights per column, c, to a constant for all columns in a matrix, the resulting matrix is both normalized and binary. Since we chose k to be 0.5 (following the 2003 Φ protocol), each connection weight was 0.5/c. This procedure ensures that C = A. We applied the normalization procedure to all matrices in all experiments in which Φ was calculated.
#### 2003 Phi
2003 Φ is a measure of the information capacity of a system based on the casual interactions within the system [13]. Φ() is the Φ of a subset, , of a stationary system, , whose connection matrix is specified by CON(). A stationary system is one in which mean and variance firing do not change over time. The activity vector, , represents the activity of each of the elements of . The activity is governed by the following dynamics (when is uncorrelated Gaussian noise with zero mean and unit variance and c is a constant):
The casual interactions of are captured by EI, where EI for a bipartition of into and is given by the following equations:
where MI is mutual information, is a system where each element is substituted with independent noise sources of constrained maximum variance, H() is entropy of system , H(,) is the joint entropy of systems and , det(C) is the determinant of matrix C, and cov() is the covariance respectively of system . Φ() system in and such that the is minimized:
where MIB is the minimum information bipartition, is a bipartition of into and , is the maximum entropy available to , and is the minimum. Then the Φ for subset is given as:
(21)
For our analyses, we considered the subset of with the greatest Φ to define the information capacity for .
Tononi et al. derived an analytical solution for finding the covariance of a system under stationary conditions [12]. Barnett et al. show the derivation to be erroneous (see [26] for a full description).
MATLAB code for the 2003 Φ (with the erroneous analytical solutions) is available from http://tononi.psychiatry.wisc.edu/informationintegration/toolbox.html [13]. We used the code as implemented with noise parameters cp = 1 and ci = 0.00001. These two values constitute the magnitude of noise from the first equation. When calculating , cp is the magnitude of the perturbation noise applied to subset while ci is the magnitude of the intrinsic noise applied to subset . Putting this in the context of the first equation (given a system bipartitioned into and
(22)
where ∗ is element-wise multiplication of vectors, and is a column vector of size n (the number of elements in ) such that:
(23)
From the above equations describing the dynamics of the system , the 2003 Φ code uses an erroneous analytical solution to find EI. Thus the code takes noise parameters cp and ci as well as the connection matrix, CON(), and returns a value for 2003 Φ. CON() represents the normalized connection matrix which is alternatively noted in the body of our paper as C. CON() (or C) is thus a matrix representing the strength of the weighted connections between elements of a system . In the context of 2003 Φ, these weights are applied to a system with linear dynamics.
#### Phi Empirical
Given a general stationary Gaussian system, , the generative model is:
where Ai is the generalized connectivity matrix acting at different times and is a stationary, Gaussian noise with zero mean and vanishing auto-covariance . Much like the above 2003 Φ model, Φ Empirical is defined as the EI over the MIB. The EI with any time lag, τ, is given by the following equations (equations 0.33 and 0.34 from [16]):
with a normalization factor K:
where and are bipartitions of ; det(C) is the covariance of a matrix C, and cov() is the covariance of a system . The MIB for a given is defined as:
Then Φ Empirical is defined as the unnormalized EI over the MIB.
Φ Empirical can be calculated analytically for system . MATLAB code is available from http://www.ploscompbiol.org/article/fetchSingleRepresentation.action? uri = info:http://doi/10.1371/journal.pcbi.10011052.s001 [16]. In our experiment, the noise, , was a Gaussian distribution with a mean of zero and a variance of one. P was set to one (for the generative equation) and thus the equation for activity of system at time t is This is the same formula governing the 2003 Φ dynamics, . Hence, the connection matrices from our paper, C, are represented as A1 in Φ Empirical notation (and CON() in 2003 Φ notation).
We calculated Φ(X) for τ = {1,2,3,4}. In addition we also performed an experiment using the value of .
### Competing interests
The authors declare that they have no competing interests.
### Authors’ contributions
MWH generated the SD measure, derived the relationships between SD and set theory, degree and the graph theory metrics, designed the experiments, generated graphs and analyzed data, and wrote and revised the manuscript. MFM was involved in the initial generation of variables to capture specialization and integration, designed the experiments, generated graphs, analyzed data and provided valuable feedback and revision on the manuscript. AW contributed some key observations, CWL contributed to the theoretical foundation and practical aspects of computation, ERR generated the idea behind the project, assisted in deriving the theoretical relationships between measures, designed the experiments, analyzed and interpreted data, and wrote and revised the manuscript. All authors read and approved the final manuscript.
### Acknowledgements
We would like to acknowledge the students and faculty of Lafayette who worked on various aspects of this project or helped in particular ways. We would like to thank Gray Sipe, Justin Bruce and Maddy Gantz for early contributions to understanding the Tononi and Sporns work. We would like to thank Ethan Berkove for help with the mathematics and for reading the manuscript. Funding for this work was provided by NSF IIS-0722211 awarded to CWL and Lafayette College.
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https://cstheory.stackexchange.com/questions/32632/time-complexity-with-irrational-exponent/32633
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# Time complexity with irrational exponent?
Is there any natural problem in P for which the best known running time bound is of the form $O(n^\alpha)$, where $\alpha$ is an irrational constant?
• Neat question! :) Sep 26 '15 at 23:28
• see also golden ratio or $\pi$ in the running time. this could conceivably be a big-list...
– vzn
Sep 27 '15 at 23:56
• Sorting a multiset is around nH+n, so if you could get H (entropy) to converge to some $n^{\alpha-1}$ that would technically qualify. I wouldn't call that "natural" though. However there might be some more natural problem where the input is reduced in this way. Sep 28 '15 at 17:31
This can be seen more clearly in the simple case of Strassen's algorithm, which has running time $O(n^{\log_2 7})$.
And, this is not precisely what you asked, but Ryan Williams has shown that all algorithms that solve SAT in space $n^{o(1)}$ require time $n^{2 \cos(\pi/7) - o(1)}$, which is another interesting and unusual appearance of an irrational constant in TCS.
• Algorithms beyond Strassen's algorithm don't really run in $O(n^\alpha)$ for their stated exponent $\alpha$. Rather, for every $\epsilon > 0$ they run in $O_\epsilon(n^{\alpha+\epsilon})$. This is due to several limits involved in obtaining $\alpha$. Sep 27 '15 at 12:49
• The time complexity of Strassen's algorithm is really an artifact of a Master recurrence $T(n) = a T(n/b) + f(n)$ solving to $\Theta(n^{\log_b a})$. You can come up with many of your favorite irrational numbers by instantiating $a$ and $b$ with different values. Sep 27 '15 at 16:31
• Yes, I agree with both. I figured I was already being loose with the definition of P, and having not actually checked if the matrix multiplication exponents are irrational. Although I would be surprised if they were rational, given how they are derived. Deep down, fast matrix multiplications still echo Strassen's basic divide and conquer method, though it is described in tensor language now. Actually, though it is easy to construct algorithms as you describe with irrational $\log_b a$, I cannot think of any other natural divide and conquer algorithm with such property, besides multiplication. Sep 28 '15 at 7:13
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https://link.springer.com/chapter/10.1007/978-1-4757-1801-0_3
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# Limits and Continuous Functions
• Serge Lang
Part of the Undergraduate Texts in Mathematics book series (UTM)
## Abstract
Let {x n} be a sequence of real numbers. We shall say that the sequence converges if there exists an element aR such that, given ε > 0, there exists a positive integer N such that for all nN we have
$$|a - {x_n}|\; < \varepsilon .$$
## Keywords
Positive Integer Continuous Function Closed Interval Open Interval Cauchy Sequence
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https://667-per-cm.net/2019/06/30/ten-fatal-flaws-in-data-analysis-charlie-kufs/
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## “Ten Fatal Flaws in Data Analysis” (Charles Kufs)
Professor Kufs has a fun book, Stats with Cats, and a blog. He also has a blog post tiled “Ten Fatal Flaws in Data Analysis” which, in general, I like. But the presentation has some shortcomings, too, which I note below.
1. Where’s the Beef? Essentially, there’s no analysis. There’s a data summary.
2. Phantom Populations Samples need to represent the population of interest. There has to be a population of interest. They need to have something specific in common which, if absent, has a good chance of affecting an outcome.
3. Wow, Sham Samples The population is real, but the samples don’t represent it well, or at all. But be careful, here! I don’t think Kufs emphasizes this enough: A sample need not contain observation of population groups in the same proportions with which they occur in the population. Professor Yves Tillé makes this point strongly in his book, Sampling Algorithms.
4. Enough is Enough No confidence and statistical power with too few, and no meaning with too many. I’d add, underscoring something Kufs says, be sure each category has a fair number of observations as well.
5. Indulging Variance Unless variance is assessed and reported, an analysis is not statistical and it’s not scientific. Means mean muck without accompanying reports of variability. There’s a lot to appreciate about variability. Properly assessed, variability can be an important tool, as it is capable of separating out subpopulations which otherwise have common means. Ignoring heteroscedasticity can break many a standard analytical tool. The place to start dealing with variance when studying a population is at the sampling plan. There’s often a tradeoff between low variance and low bias. Merely calculating and reporting a standard deviation at the end of an analysis is almost always insufficient treatment.
6. Madness to the Methods Data inspection, cleaning, correcting, and testing for assumptions of modeling are unglamorous, tedious, and time consuming parts of any statistical analysis or data science project. It is also a portion which is hard to defend, since, in industry, management is sometimes impatient to see results coming from an allocation of expensive people and resources. But these steps are totally necessary. Without the last step, testing, you cannot know if the data are sufficiently cleaned or representative.
7. Torrents of Tests Kufs treatment of the multiple testing problem is old (Bonferroni), whether addressed from a quasi-Frequentist perspective or the more modern Bayesian one. There are now techniques for controlling family-wise error rates when large numbers of tests are conducted. Bayesian methods don’t have a problem with multiple comparisons. That’s one reason why I use them (a lot).
8. Significant Insignificance and Insignificant Significance Ah, significance tests! I could go on and on about these, and often have. The kindest thing to say here is a quote from Jerome Cornfield (1976): “The most general and concise way of saying all this is that $p$-values depend on both the $x$ observed and on the other possible values of $x$ that might have been observed but [were not], i.e., the sample space, while the likelihood ratio depends only on the observed $x$.”
9. Extrapolation Intoxication This is a caution against making the same mistake NASA and its subcontractors did when making the fateful decision to launch the Space Shuttle Challenger after it was exposed to freezing temperatures.
10. Misdirected Models Models are critical for understanding data, whether they are derived from domain knowledge, like physical theory, or not. There are many ways theories or hypotheses upon which models are based can themselves be wrong. The most important criterion a theory or hypothesis needs to have is it must be falsifiable. Extending, then, every model much have diagnostics within it which tell when the model is broken. This can be inherent to the application of the model, or it can be done by comparing its performance with a straw man model which is completely nonsensical but is fit to the same data. However, in this day and age there are such things as non-mechanistic empirical dynamic modeling which have shown success in the absence of underlying theory.
In practice, I witness projects running aground on these sandbars way too often. Kufs’ cautions are good. But Kufs’ advice could use an update.
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http://math.stackexchange.com/questions/296551/what-is-a-minimal-polynomial-of-a-group-element-and-why-would-we-care-if-it-was/310184
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What is a minimal polynomial of a group element, and why would we care if it was quadratic?
EDIT: the $p$-stable definition I give below is incorrect. I have included the correct definition as an answer to this question.
I am trying to understand the definition of a p-stable group. The first part of the definition is
A faithful representation of a finite group $G$ on a vector space over a field of characteristic $p\not= 2$ is called $p$-stable if no $p$-element of $G$ has a quadratic minimal polynomial.
What does it mean for a group element to have a minimal polynomial?
Additionally, any intuition on a meaningful interpretation of this definition would be much appreciated. What is special about elements which have quadratic minimal polynomials? Why would we want to get rid of them? What's wrong with $p=2$?
After this,
1. If $G$ has no nontrivial $p$-subgroups, $G$ is $p$-stable if every faithful characteristic $p$ representation is $p$-stable.
2. If $1<O_p(G)$ and $1=O_{p'}(G)$ then $G$ is $p$-stable if for all normal nontrivial $p$-subgroups $P$, for every $p$-element $x$ such that $[[x,P],x]=1$, the image $\overline{x}$ in $G/C_G(P)$ is contained in a normal $p$-subgroup.
3. If $1<O_p(G)$ and $1<O_{p'}(G)$, then $G$ is $p$-stable if $G/O_{p'}(G)$ is $p$-stable.
What, mainly, is the connection between the $p$-stable representation definition and $\#2$? Are these somehow the same, but in a different light?
(I see that $[[x,P],x]$ are elements of the form $p^{-1}x^{-1}pxx^{-1}x^{-1}p^{-1}xpx=(x^{-1})^p(p^{-1})^xpx$, so if that is equal to $1$ then $px=p^xx^p$. So there's sort of a "double twist" happening, which must be important in some way; but I don't see immediately any connection to minimal polynomials.)
Sorry if these are basic questions on advanced material. I am sure the answer to this part is, to some extent, because this is a technical definition which is made to prove things with, but even the broadest intuition on this would help.
-
I don't have any intuition on the definition. But presumably minimum polynomial of a group element $g \in G$ with respect to a representation $\phi$ refers to the minimum polynomial of $\phi(g)$. – JSchlather Feb 6 '13 at 20:31
I think, from the phrase "satisfying a technical condition introduced by Gorenstein and Walter ... in order to extend Thompson's uniqueness results in the odd order theorem" this definition came backwards - it was defined to be useful based on an existing argument that worked in other cases. I can't be sure of that, but that feels likely. – Thomas Andrews Feb 6 '13 at 20:54
@ThomasAndrews Maybe somebody who knows how these things were used in the classification theorems can help. If it is backwards like that, it would at least be useful to know what they were trying to do with it. – Samuel Handwich Feb 6 '13 at 20:58
That wikipedia page is also somewhat suspect - it has no links to external definitions. (I thought $p$-element would be an element of order $p$, but later definitions would be meaninngless if that was true .) – Thomas Andrews Feb 6 '13 at 21:05
@ThomasAndrews I think a $p$-element is supposed to be an element of $p$-power order. – Samuel Handwich Feb 6 '13 at 21:08
What is special about elements which have quadratic minimal polynomials?
As the action of a $p$-element $x\in G$ on a (finite dimensional) vector space $V$ over a field of characteristic $p$ is nilpotent, defining $V_0 = V, V_{i+1} := [V_i, x]$ you get $V_n = 0$ for some $n\ge 0$. As $x$ acts trivially if $n\le 1$, the minimal nontrivial case is $n=2$, i.e., $x$ acts quadratically.
Why would we want to get rid of them?
An action of $G$ on $V$ is $p$-stable if for all $a \in G$ holds $$[V, a, a] = 1 \implies a\mathrm{C}_G(V) \in \mathrm{O}_p(G/\mathrm{C}_G(V)).$$ The purpose of this condition is to exclude sections of $G/\mathrm{C}_G(V)$ that are isomorphic to $\mathrm{SL}_2(p)$ (and act "naturally" like $\mathrm{SL}_2(p)$, see for example the remark after Theorem 9.1.4 in [KS]). If you have a group $G$ with $\mathrm{C}_G(\mathrm{O}_p(G)) \le \mathrm{O}_p(G)$ and the action of $G$ on the chief factors of $G$ in $\mathrm{O}_p(G)$ is $p$-stable then Glauberman's ZJ-Theorem states that $Z(J(S))$ is normal $G$ for every $p$-Sylow subgroup $S$ of $G$ (see beginning of section 9.4 in [KS]).
What's wrong with p=2?
Every element of order $2$ acting non-trivially on a vector space over a field of characteristic $2$ acts quadratically (according to the remark after 9.4.5 in [KS] you can replace $p$-stability by excluding sections of $G$ isomorphic to $\mathrm{SL}_2(2) = S_3$ directly to get meaningful results for $p=2$).
[KS] Kurzweil, Stellmacher: The Theory of Finite Groups
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I don't study these things so I can't give you any intuition, but here is the definition of the minimal polynomial:
Given a representation $\phi\colon G \to \mathrm{GL}_n(k)$ and an element $g \in G$ the matrix $A = \phi(g)$ is square so given any polynomial
$$f(x) = c_nx^n + c_{n-1}x^{n-1} + \cdots c_1x + c_0$$
it is perfectly well defined to set
$$f(A) = c_nA^n + c_{n-1}A^{n - 1} + \cdots + c_1A + c_0I$$
where $I$ is the $n \times n$ identity matrix. The minimal polynomial of $g$ with respect to $\phi$ is then the monic polynomial $f$ of minimal degree such that $f(A) = 0$ (the $n \times n$ matrix whose entries are all zero).
Also: we can define the ideal $\mathrm{ann}(A)$ of all polynomials $p$ such that $p(A) = 0$. The minimal polynomial $f$ is the monic polynomial that generates this ideal. So if $p(A) = 0$ then you can write $p = fh$ for some other polynomial $h$.
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If there are no $p$-subgroups of $G$, then there are no $p$-elements of $G$, and therefore, by the definition of $p$-stable representation, all faithful representations are $p$-stable, since a representation being $p$-stable is defined only in terms of how it affects $p$-elements, and there are none.
There are lots of indications that this Wikipedia page is not "mature." Specifically, there are no links to external articles defining the terms, and there are cases of mangled grammar.
I would not trust that page. Probably best to go to the primary source.
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I have found a paper in my library which includes the definition, which has some differences. Should I rewrite this question or start a new one? – Samuel Handwich Feb 6 '13 at 21:17
It depends on your intent. I think you have the answer to your "technical" question: What does it mean by the minimal polynomial? The bigger question of "why this definition?" is still open, and it does seem like a separate question. – Thomas Andrews Feb 6 '13 at 21:19
As @ThomasAndrews suggested, the definition given on Wikipedia was not correct. I have located the definition in an article by Glauberman:
1. Let $p$ be an odd prime and $G$ be a finite group with $O_p(G)\not= 1$. Then $G$ is $p$-stable if it satisfies the following condition: Let $P$ be an arbitrary $p$-subgroup of $G$ such that $O_{p'}(G)P$ is a normal subgroup of $G$. Suppose that $x\in N_G(P)$ and $\overline{x}$ is the coset of $C_G(P)$ containing $x$. If $[P,x,x]=1$, then $\overline{x}\in O_n(N_G(P)/C_G(P))$.
2. Define $\mathcal{M}_p(G)$ as the set of all $p$-subgroups of $G$ maximal with respect to the property that $O_p(M)\not= 1$.
3. Let $G$ be a finite group and $p$ an odd prime. Then $G$ is called $p$-stable if every element of $\mathcal{M}_p(G)$ is $p$-stable.
(I am not sure what little $n$ is in (1). I am guessing just any $n\in \mathbb{N}$?)
So I guess that $[P,x,x]$ is a commutator condition that no critical $p$-subgroups are allowed to have when we want $G$ to be $p$-solvable. (Evidently, the case $p\not= 2$ is degenerate with respect to the $[P,x,x]$ condition, which is why it is not included in this.) As a side note, excluding $SL(2,p)$ from a group implies that it is $p$-stable - I suspect because the $[P,x,x]$ relation gives rise to that sort of subgroup.
I am still not sure what to think intuitively about what makes these groups "stable" with respect to $p$. Perhaps I will find and read the papers in the bibliography.
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If you can get the book The Theory of Finite Groups by Kurzweil and Stellmacher, take a look at chapter 9 "Quadratic Action". – j.p. Feb 6 '13 at 21:50
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https://mooseframework.inl.gov/source/vectorpostprocessors/HistogramVectorPostprocessor.html
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HistogramVectorPostprocessor
Short Description
Compute a histogram for each column of a VectorPostprocessor
Description
Used to compute the histogram for all columns of another VectorPostprocessor (VPP). The only inputs are the other VPP (vpp) and the number of bins to use in the histogram (num_bins).
This will actually generate three columns for each column in the original VPP:
• column_name: The histogram data
• column_name_lower: The lower bound for each bin
• column_name_upper: The upper bound for each bin
Plotting
MOOSE comes with built-in plotting capabilities that can help plot the output of a HistogramVectorPostprocessor. These plotting capabilities are part of the Chigger suite of visualization tools located in the moose/python directory. To use them you must add the full path of your moose/python directory to the environment variable called $PYTHONPATH using something like: export PYTHONPATH=/full/path/to/moose/python:$PYTHONPATH
Once that is completed a script such as the following will plot your data:
import matplotlib.pyplot as plt
import mooseutils
# Create Figure and Axes
figure = plt.figure(facecolor='white')
# Grab upper and lower bin bounds
lower = data('value_lower')
upper = data('value_upper')
# Compute the midpoint and width of each bin
mid = (lower + upper) / 2.0
width = upper - lower
# Grab the data to be plotted
y = data('value')
# Plot everything
axes0.bar(mid, y, width=width)
# Show the plot and save it
plt.show()
figure.savefig("output.pdf")
Input Parameters
• vppThe VectorPostprocessor to compute histogram of
C++ Type:VectorPostprocessorName
Options:
Description:The VectorPostprocessor to compute histogram of
• num_binsThe number of bins for the histograms
C++ Type:unsigned int
Options:
Description:The number of bins for the histograms
Required Parameters
• execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.
Default:TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE INITIAL LINEAR NONLINEAR TIMESTEP_END TIMESTEP_BEGIN FINAL CUSTOM
Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.
• contains_complete_historyFalseSet this flag to indicate that the values in all vectors declared by this VPP represent a time history (e.g. with each invocation, new values are added and old values are never removed). This changes the output so that only a single file is output and updated with each invocation
Default:False
C++ Type:bool
Options:
Description:Set this flag to indicate that the values in all vectors declared by this VPP represent a time history (e.g. with each invocation, new values are added and old values are never removed). This changes the output so that only a single file is output and updated with each invocation
Optional Parameters
• enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
Description:Set the enabled status of the MooseObject.
• use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False
C++ Type:bool
Options:
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
• outputsVector of output names were you would like to restrict the output of variables(s) associated with this object
C++ Type:std::vector
Options:
Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object
• control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector
Options:
Description:Adds user-defined labels for accessing object parameters via control logic.
• allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
Default:False
C++ Type:bool
Options:
Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
• force_preauxFalseForces the GeneralUserObject to be executed in PREAUX
Default:False
C++ Type:bool
Options:
Description:Forces the GeneralUserObject to be executed in PREAUX
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https://physics.stackexchange.com/questions/171182/excitation-energy-of-carotene-using-the-particle-in-a-box-model
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# Excitation energy of carotene using the particle in a box model
I'm practicing for an exam and I came across the following question:
The linear, conjugated π-electron system of a carotene molecule comprises 11 atoms and the distance between two atoms is 1.4 Å. Calculate the excitation energy and the wavelength of the radiation for an electron in the described system using the particle in a box model.
My (probably wrong) approach of solving this problem is as follows:
Assume the carotene molecule can be modeled as a particle in a 1 dimensional box of length 15.4 Å. An electron is excited when it goes from the ground state up to the next energy level, so the excitation energy is $\Delta E=E_2 - E_1$ with $E_n=\frac{n^2h^2}{8mL}$.
So calculating the excitation energy with $h=6.626*10^{-34} J*s$, $m=9.109*10^{-31} kg$ and $L=1.54*10^{-9}m$ gives:
$\Delta E =\frac{2^2h^2}{8mL} - \frac{1^2h^2}{8mL} = 3*\frac{h^2}{8mL} = 3*\frac{(6.626*10^{-34})^{2}}{8*9.109*10^{-31}*1.54*10^{-9}}=1.174*10^{-28} J$.
Using the formula $\lambda = \frac{hc}{\Delta E}$ to calculate the wavelength gives:
$\lambda = \frac{hc}{\Delta E} = \frac{6.626*10^{-34} * 2.998*10^{8}}{1.174*10^{-28}} = 1692.1m$.
That's 1692 meters. Quite obviously wrong... Now I don't have the solutions to this problem, so I don't actually know what's supposed to be the right answer, but I know mine is wrong.
So yeah, if someone could point out what I'm doing wrong, I'd be really grateful!
$$E = \frac{n^2h^2}{8mL^2}$$
Your mistake is that you have $L$ not $L^2$ in the denominator so your answer is a factor of $L$ too small.
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https://www.physicsforums.com/threads/simple-proof-for-arbitrary-period.417563/
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# Simple proof for arbitrary period
1. Jul 21, 2010
### zwoodrow
if f(t) has period T then f(kt) has a period T/k. What is a simple proof of this.
2. Jul 21, 2010
### Office_Shredder
Staff Emeritus
Why don't you just see what f(k(t+T/k)) is?
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http://mathhelpforum.com/calculus/203842-word-problem-involving-derivatives-need-answers.html
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# Thread: Word problem involving derivatives. Need answers!
1. ## Word problem involving derivatives. Need answers!
The value of an automobile purchased in 2007 can be aproximated by the function V(t)= 25(0.85)^t,
where t is the time, in years, from the date of purchase, and V(t) is the value, in thousands of dollars.
a.) Evaluate and interpret V(4)
b.) Find an expression for the derivative of V(t), including units.
c.) Evaluate and interpret V'(4)
d.) Use V(t) and V'(t), and any other considerations you think are relevant to write a paragraph in support of or in opposition to the following statement:
"From a monetary point of view, it is best to keep this vehicle as long as possible."
I really want to see feedbacks for question d, so please explain it in details. Thank you!
2. ## Re: Word problem involving derivatives. Need answers!
Hey Mathinik.
We know that if something has a negative derivative it means it's decreasing. What can you say about the derivative for t > 0 and what can you conclude about the value in the long term given this information?
3. ## Re: Word problem involving derivatives. Need answers!
Chiro,
I still don't get it!
4. ## Re: Word problem involving derivatives. Need answers!
If something is continually decreasing (i.e always getting smaller) what does that mean about the value? What does this imply later in the future (if it's decreasing, will it be worth a lot less or a lot more)?
5. ## Re: Word problem involving derivatives. Need answers!
It's getting cheaper each year. It will be worth a lot less. So it is best to not keep this vehicle as long as possible?
6. ## Re: Word problem involving derivatives. Need answers!
Need answers!!!
7. ## Re: Word problem involving derivatives. Need answers!
need help still
8. ## Re: Word problem involving derivatives. Need answers!
You're not going to get answers. You are going to use the guidance given by the members here to come to the answers YOURSELF. Also, I don't see how your original function can possibly have been written correctly. You would expect a car's value to decrease over time, but what you have written is an INCREASING function.
### partial derivatives word problem
Click on a term to search for related topics.
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https://math.stackexchange.com/questions/720578/what-is-the-probability-that-the-smartest-of-them-has-iq-score-above-120
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# What is the probability that the “smartest” of them has IQ score above 120?
Suppose that we model the distribution of IQ scores in the general population as a normal random variable with mean 100 and standard deviation 15. Find the probability that a randomly selected person's IQ score is between 125 and 130.
Suppose that 5 people are chosen independently at random. What is the probability that the “smartest” of them has IQ score above 120?
How do account for the "smartest" of them? Where do I start?
• "the smartest of them has IQ score above 120" is the opposite of "all of them have IQ score below 120" – miracle173 Mar 21 '14 at 1:06
For the second problem: $\Pr(\max_{i \le n \le 5} X_i \le 120) = \Pr(X_i \le 120)^5$. Now use $\Pr(\max_{i \le n \le 5} X_i > 120) = 1 - \Pr(\max_{i \le n \le 5} X_i \le 120)$.
Let $X_i$ be $i$'s IQ. This is a random variable such as $X = 100 + 15G$ where $G\sim N(0,1)$. Now assume that random selected person's IQs are independant:
1. $P(\text{a randomly selected person's IQ score is between 125 and 130})=P_1$ $$P_1 = P(125<100 + 15G<130) = P(5/3 <G<2)$$
2. Assume that "more intelligent" means "with highest IQ" (hum.). $P(\text{the “smartest” of 5 people chosen independently...})=P_2$. $$P_2 = P(\max_{1\le i\le 5} X_i\ge 120) = 1 -P(\max_{1\le i\le 5} X_i<120) \\= 1 -P( X<120)^5 = 1 - P(G < 4/3)^5$$ We use independance in the third equality.
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http://physics.stackexchange.com/questions/44826/proca-equation-question/44827
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# Proca equation question
i'm having trouble understanding the Proca equation
$$(g_{\mu\nu}(\Box+\mu^2)-\partial_{\mu}\partial_{\nu})\varphi^{\nu}=0$$
where $g_{\mu\nu}$ is the metric and $\mu$ is a parameter. Where is the wrong assumption?
$$(g_{\mu\nu}(\partial_{\mu}\partial^{\mu}+\mu^2)-\partial_{\mu}\partial_{\nu})\varphi^{\nu}=0$$ $$((\partial_{\mu}g_{\mu\nu}\partial^{\mu}+g_{\mu\nu}\mu^2)-\partial_{\mu}\partial_{\nu})\varphi^{\nu}=0$$ $$((\partial_{\mu}\partial_{\nu}+g_{\mu\nu}\mu^2)-\partial_{\mu}\partial_{\nu})\varphi^{\nu}=0$$
which implies $$\mu^2=0$$ not the case. The problem is using $\Box =\partial_{\mu}\partial^{\mu}$ instead of other index, say $\alpha$?. In that case how can I show that
$$\partial_{\nu}\varphi^{\nu}=0$$
Any hit will be appreciated.
-Edit- Reference Bjorken et.al Relativistic Quantum Fields page 23
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Hint: Contract with derivative $\partial^{\mu}$ on both sides of your first equation (v1) to deduce that
$$\mu^2 \partial_{\nu}\varphi^{\nu}~=~0.$$
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$$\partial^{\mu}(g_{\mu\nu}(\Box+\mu^2)-\partial_{\mu}\partial_{\nu})\varphi^{\nu}=0$$ $$\partial^{\mu}g_{\mu\nu}\Box\varphi^{\nu}+\partial^{\mu}g_{\mu\nu}\mu^2 \varphi^{\nu}-\partial^{\mu}\partial_{\mu}\partial_{\nu}\varphi^{\nu}=0$$ $$\partial_{\nu}\Box\varphi^{\nu}+\partial_{\nu}\mu^2 \varphi^{\nu}-\Box\partial_{\nu}\varphi^{\nu}=0$$ Given that derivatives commute: $$\Box\partial_{\nu}\varphi^{\nu}+\mu^2\partial_{\nu} \varphi^{\nu}-\Box\partial_{\nu}\varphi^{\nu}=0 \Rightarrow \mu^2\partial_{\nu} \varphi^{\nu}=0$$ – Jorge Nov 22 '12 at 11:24
I still don't have the reputation to comment everywhere so I leave this as an answer although it's a comment.
Be careful when defining the sum indexes. There are two things that you did wrong in your calculation.
1. You said correctly that $\square=\partial_\mu \partial^\mu$ but those are indexes to express the sum so wrinting$$g_{\mu\nu}\square=g_{\mu\nu}\partial_\mu \partial^\mu,$$ is wrong, you should write something like$$g_{\mu\nu}\square=g_{\mu\nu}\partial_\rho \partial^\rho.$$
2. The other thing you should be careful with is in the second step you put the metric between the partial derivatives but then you're are taking the partial derivative of the metric and that is not correct.
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About 1: yes, thanks, this is what I tried to mean with my $\alpha$ index About 2: There is no problem because the metric is constant, but thanks for the hint! – Jorge Nov 22 '12 at 12:06
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https://quuxplusone.github.io/blog/2018/09/10/the-yellowbird-mistake/
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# Homeworlds: The Yellowbird Mistake
This post is about Binary Homeworlds, the “space chess” game invented by John Cooper and popularized by (among others) Andy Looney. You can play Homeworlds online at SuperDuperGames. Sadly a full rules explanation is out of scope for this blog post, but maybe sometime. In this post I just want to talk about a specific tactical error that (sigh) I keep making.
Aficionados of Homeworlds will have heard of the “Bluebird Mistake.” Andy Looney invented the name for this pattern; it’s named for the Bluebird coffeeshop in Amsterdam where Andy fell victim to it. Basically it’s where you look at the board and think, “My homeworld is safe from overpopulation because I have only two pieces of any one color there; three pieces is where it gets dangerous. Also, my opponent only has one piece within striking distance.” And then on the next move, your opponent sacrifices y3 to move two ships into your homeworld (one of those ships moving two hops, which is how it escaped your notice originally), and boom goes the star system.
Today I wrote a quick-and-dirty filter to scan through my archive of 699 games (2005–2009) for cases of the following pattern, which I will call a “Bluebird move”:
• The move consists of a y3 sacrifice, three moves, and a catastrophe.
• The catastrophe is at the defender’s homeworld.
• The defender’s homeworld had only two pieces of the catastrophed color.
• Both of the ships moved are of the catastrophed color, and one of them moves two hops.
Of my archive’s 699 games, 18 of them were won via a Bluebird move. In 5 of those 18 games, prior to the final catastrophe, the losing player actually had more ships on the board than the winner did!
Looking at games where a Bluebird move happened but was not necessarily the winning move, we find 77 instances across 73 unique games. (That is, four games saw this pattern arise repeatedly.)
But I wanted to talk about a different pattern, one that to my knowledge does not have an accepted name yet. Basically this one is where you look at the board and think, “I don’t have to worry about my opponent building material on his turn; he won’t dare sacrifice his sole g3 at home since he’s unable to rebuild it. So the best he can do is get a medium ship somewhere.” And then on the next move, your opponent does sacrifice his g3 to build that ship you were looking at, plus two more ships, one of which is a large of a different color (let’s say, blue) in his home system. So he’s still got a big ship at home after all — it’s just changed colors from green to blue — and now he’s got a monopoly on blue and he’s going to be farming big ships for the rest of the game (which is likely to be nasty, brutal and short).
Here’s the position in my most recent game where I let this happen to me.
ajo (0, y3b2) g3y1-
Felix (1, r1b2) -y1b1g3
Rim (g3) -b1
Alpha (b1) g1y1-
Stash: r1r1r2r2r2r3r3r3y2y2y2y3y3g1g1g2g2g2b2b3b3b3
ajo: build g1 at ajo
Felix: sacrifice g3 at Felix; build b2b3 at Rim; build b3 at Felix (!)
For obvious reasons, I have decided to call this tactical error the “Yellowbird Mistake.”
I wrote a second quick-and-dirty filter to scan through my archive of 699 games for cases of the following pattern, which I will call a “Yellowbird move”:
• The move consists of a sacrifice at home and three builds.
• The sacrificed g3 is both the only green, and the only 3, in the attacker’s home system.
• At the start of the turn, there are no 3s exposed in the stash.
• At the end of the turn, the attacker once again has a 3 at home, and the defender has no way to build any 3 of his own (not even by sacrificing).
Of my archive’s 699 games, we find 49 Yellowbird moves across 42 unique games. (Five games saw this pattern arise repeatedly.) In only one case was the resulting advantage immediately erased by a catastrophe. In 26 of the 49 cases, the result was that the attacker gained a monopoly on the color they’d just built — meaning that the defender had no way to build, swap for, or capture any ship of that color on their next turn. In 14 of those 26 cases, that monopoly was in blue.
(In general this would just be because the stash was void in that color. My analysis doesn’t tell us anything about the imperviousness, or otherwise, of such monopolies.)
The moral of the story, such as it is, is: Watch out for unexpected green sacrifices. One doesn’t need a factory to become a monopolist!
Posted 2018-09-10
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https://www.jacobmartin.org/notes/audio-math.html
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# The Math Behind Audio Equipment
I purchased a USB mic years ago for video conferencing and so forth, but this mic turned out to be insufficient for recording and broadcasting the full voice that I am obtaining with my opera training. A surprising bit of math is regularly involved in rating and judging audio equipment, and I haven’t seen it fully expounded elsewhere, so I attempt to here.
## 1 Sound Pressure Level and the Logarithmic Scale
Sound is an acoustic vibration (mostly) transmitted through the ambient air. It is modeled a adiabatic pressure perturbations, thus we assume that the total mass and temperature of air remains constant when we monitor for sound.1
Sound is most commonly measure by a diaphragm, which oscillates due to sound pressure levels, which are the instantaneous difference in sound pressure in a sound wave relative to the mean pressure of the air “at rest,” as it were. There is quite a difference in order of magnitude between these. Static air pressure is about $$100$$ kPa ($$1 \times 10^5$$ Pa), while the reference threshold for human hearing is about $$20$$ μPa ($$2 \times 10^{-5}$$ Pa) sound pressure-level (SPL).
The power dissipated per unit area by a sound wave is called its sound intensity $$I$$. The sound intensity is proportional to the square of the sound pressure level $$p$$. $I \propto p^2$ I omit the full derivation, but it is basically the same as the derivation of the fact that the power dissipation of a resistor is proportional to the square of the current.
The human ear generally perceives loudness as being proportional to the log of the intensity of the sound, so we measure the loudness of sound in decibels of the square of the sound pressure level, relative to the reference threshold of $$p_r = 20$$ μPa. $L_p = 10 \log_{10} \left( \frac{p^2}{p_r^2} \right) = 20 \log_{10} \frac{p}{p_r}.$ The units of $$L_p$$ are called dB SPL, for decibels, Sound Pressure Level. Thus, every 10 dB SPL increase is an order of magnitude increase in sound intensity and two orders of magnitude increase in raw sound pressure.
### 1.1 Acoustic Impedance and Attenuation
Acoustic intensity obeys an inverse square law. The acoustic intensity at a point beyond the sound source is proportional to the inverse of the square of the distance $$r$$ away from the sound source. Moreover, because air is viscous and thus not totally lossless, the attenuation due to distance is also dependent in part on the frequency (higher frequencies are more quickly attenuated). The equations for this are very complicated in the general case. In general, we can use a few relations to describe this. Let $$f$$ be the frequency of the sound. $I \propto r^{-2 \alpha(f)} \qquad \alpha(f) \propto f \qquad \alpha(f) \geq 1$
Thus, we can say that for every doubling of the distance between the source and the sensor, the SPL is attenuated by $$10 \times \log_{10} ( 1 / 4) \approx -6$$ dB.
### 1.2 The Response of the Human Ear
The human ear cannot differentiate loudness well above about 130 dB SPL. (Thus its dynamic range is about 130 dB.) Furthermore, this is about the level where hearing damage sets in, and hearing damage can set in at much lower SPL over long period of time.
The human ear can reliably differentiate frequencies about from about $$20$$ Hz to about $$20 000$$ Hz ($$20$$ kHz). However, it doesn’t perceive them equally. The ear will perceive a 2kHz sound as being about 10 dB louder than a 200 Hz sound at the same SPL. Thus A-weighting was conceived of as a way of compensating for the non-constant response of the human ear in the frequency domain. Age also significantly affects the ability of the ear to hear higher frequencies, as does damage or hearing loss from other sources.
## 2 The Fourier Transform
Because so many of these responses are frequency-dependent, it is useful to take a signal in the time domain and translate it into the frequency domain. This is done with the fourier transform. Suppose a signal $$s(t)$$ is sampled over a period of $$0 \leq t \leq T$$, then the constituent frequencies of the “averaged” sound is $\hat{s} (f) = \int_0^T s(t) e^{-2\pi i t f} \mathrm{d}t.$ Thus if we restrict the time sample domain to a small period of time where the sound pressure level is relatively periodic (a single tone from a single instrument), it is easy to break it down into its constituent frequencies.
## Footnotes:
1
Of course, the temperature and mass of air does change, but we can easily assume that those changes are orders of magnitude slower than the general frequencies of audible sound. In general, we can assume these changes affect both sides of the diaphragm measuring the sound (the diaphragm in a microphone, or the ear drum as the case may be) at roughly the same time, relative to the fast perturbations of audible sound.
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https://zbmath.org/?q=an%3A0753.60045
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×
## On the Azéma martingales.(English)Zbl 0753.60045
Séminaire de probabilités XXIII, Lect. Notes Math. 1372, 66-87 (1989).
[For the entire collection see Zbl 0722.00030.]
The first part of this paper introduces what is called a structure equation $d[X,X]_ t=dt+\Phi_ tdx_ t, \tag{SE}$ where $$X$$, the solution to the equation for given $$\Phi$$, is a martingale, $$\Phi$$ is a predictable process, and $$\int\Phi dX$$ is a martingale. Properties of solutions $$X$$ to SEs are studied, examples are given, and both existence and uniqueness questions are addressed. The second part of the paper analyzes solutions to a specific class of SEs, $$d[X,X]_ t=dt+(a+bX_{t-})dt$$, where $$a$$ and $$b$$ are constants, $$b\neq 0$$. When $$a=0$$ and $$b=-1$$, a solution is the martingale first obtained by Azéma, $$X_ t=(\text{sign} B_ t)\sqrt{2(t-G_ t)}$$, where $$B_ t$$ is Brownian motion and $$G_ t$$ is the last time up until $$t$$ when $$B_ t=0$$. One major result (Proposition 6) is: a) If $$a=0$$ and $$b\leq 0$$, the solution is unique in law and is a strong Markov process; b) if $$-2\leq b\leq 0$$, the solution has the chaotic representation property.
### MSC:
60G44 Martingales with continuous parameter 60H05 Stochastic integrals
Zbl 0722.00030
Full Text:
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https://matheducators.stackexchange.com/questions/7281/how-to-explain-the-difference-between-the-fraction-a-b-and-the-ratio-a-b/7290
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# How to explain the difference between the fraction a / b and the ratio a : b?
I found it difficult to explain the difference between the fraction a / b and the ratio a : b. This subject is for pupils of grade 5. So is there a real difference between them and how to explain the difference in simple way ?!
• Could you explain the difference to me (Student of Mathematics)? – Jasper Jan 24 '15 at 12:19
• @Jasper If you consider a:b as the number z such that bz=a, then writing it in fraction form gives what you want. I consider a:b as doing fractions without using fractions. This way, it actually generalizes quite nicely in commutative algebra. – Chris C Jan 24 '15 at 13:54
• But is the ratio a:b is a number ? – Abdallah Abusharekh Jan 24 '15 at 18:24
• Suppose there really is a difference between these two alleged concepts. Does having a clear distinction between these concepts make it easier to solve any real-world problems? Especially if you are careful to use units? – Jasper Jan 25 '15 at 21:20
• @AbdallahAbushrekh It can be. I found the wikipedia page to be quite useful: en.wikipedia.org/wiki/Ratio – Chris C Jan 25 '15 at 21:28
This paragraph from Adding It Up is a good overview of the context of this question. Rational numbers are complex because there are multiple interpretations (meanings) as well as multiple forms for expressing a rational number.
As we said at the beginning of the chapter, rational numbers can be expressed in various forms (e.g., common fractions, decimal fractions, percents), and each form has many common uses in daily life (e.g., a part of a region, a part of a set, a quotient, a rate, a ratio). One way of describing this complexity is to observe that, from the student’s point of view, a rational number is not a single entity but has multiple personalities. The scheme that has guided research on rational number over the past two decades identifies the following interpretations for any rational number, say 3/4: (a) a part-whole relation (3 out of 4 equal-sized shares); (b) a quotient (3 divided by 4); (c) a measure (3/4 of the way from the beginning of the unit to the end); (d) a ratio (3 red cars for every 4 green cars); and (e) an operation that enlarges or reduces the size of something (3/4 of 12). The task for students is to recognize these distinctions and, at the same time, to construct relations among them that generate a coherent concept of rational number. Clearly, this process is lengthy and multifaceted.
I think it is important for students to understand the connection as well as the distinction between the fraction and the ratio. They can both be written as 3/4. The point to make to students is that the expression 3/4 can be interpreted in different ways. It has different meanings that are mathematically equivalent. So the students should realize that the ratio 3:4 has the same meaning as the ratio 3/4. A second point to make is that there are different forms for writing rational numbers. Using the colon and the bar are just different ways of writing the ratio. As a ratio it is a correspondence of 3 things to 4 things. The students should also realize that the expression 3/4 can be interpreted as a fraction, 3 out of 4 equal portions of some whole. The fraction is a part-to-whole ratio. There are also part-to-part ratios, like one blue dot to 2 yellow dots. Since there are three dots in total, I can also compare the blue dots to the total, giving 1 to 3 as a ratio, or as a fraction 1/3.
Give lots of examples to make it concrete. Answer their questions to clarify the connection and the difference. Then ask them questions and let them explain their thinking. For example, “There are 12 boys and 14 girls in this class. What fractions and ratios can you make from these numbers?”
• I don't understand this answer, so it's hard for me to imagine how children could understand this approach. – Ben Crowell Apr 30 '16 at 3:09
• This is not correct. A 3 to 4 ratio, as in cooking, means for every 7 cups of stuff used, 4 are of one type, and 3, the other. Each ingredient is then 4/7 or 3/7 of the total. The G/B ratio is 12/14 or 6/7 but there are 12/26 or 6/13 students are girls. The example doesn't make this clear. – JTP - Apologise to Monica May 7 '16 at 10:20
• @JoeTaxpayer "3 to 4 ratio" is not a ratio, it is a proportionality. 4/7 and 3/7 are ratios. – Rusty Core Aug 30 '19 at 18:54
I find this diagram helpful when relating the two:
It comes from a model curriculum unit on Rates and Ratios for 6th graders (you can see them all here after registering), and I have found this particular graphic very helpful with math content professional development with 6th grade math teachers.
• thank you Tamisha for the diagrame .. you have just supported my undrestandind for the whole matter – Abdallah Abusharekh Feb 1 '15 at 18:06
• Glad I could assist. :) – Tamisha Thompson Feb 2 '15 at 0:18
I always get students to colour in dots. 1 red and 2 blue. Here the ratio is 1:2 red to blue. I ask, "What fraction are red?" Hopefully someone says $\frac{1}{2}$ and we can discuss the misconception. In terms of how to relate $\frac{1}{2}$ to the ratio 1:2 I do it after establishing the equivalence of ratio by scaling up both sides. I want to make green from blue and yellow in the ratio 1:2. I have 2 tins of blue how many yellow? Students often say that's easy just double the tins of yellow because you have doubled the blue. Now I ask them if I had 1000 yellow or something like they say 500 but this time because they recognise there are $\frac{1}{2}$ the number of yellow. A subtle change but one that recognise the proportion of blue and yellow is the same for equivalent ratios. Hope this helps.
• Same thing comes up with odds and probability. If the odds are 1 to 2 against you, then the probability of winning is 1/3. – Gerald Edgar Jan 24 '15 at 17:12
• Thank you. But if we have 1 red and 2 blue the fraction will equal 1/3 not 1/2 ! – Abdallah Abusharekh Jan 24 '15 at 18:27
• hence the "misconception" in saying it. – Lucas Virgili Jan 24 '15 at 18:34
I want to build a factory and I go to a bank for a loan, to finance part of the investment cost.
Bankers tend to think in $a:b$: "How many euros we will lend for every euro the compnay will invest". And they tend to have rules of thumb on the matter, say a $3:1$ rule. From the point of view of the company, this could be written $1:3$ and here, confusion may arise more easily, because "$1/3$" should be interpreted as "the compnay will invest one third of what the bank will lend" and not as "one third of the total cost of the factory".
To arrive at this last magnitude the relation is always $a:b \rightarrow \frac {a}{a+b}$
More generally, I think a fraction $a/b$ (which then can be written also as a number, a decimal, etc), is meanigfull only when $a$ and $b$ measure same entities in nature (in my example, money in the same currency). But the concept represented usually by $a:b$ can bring together items that are not alike (say, "$a$ car-accident deaths per $b$ kilometers of highways), in which case there is no meaningful interpretation of $a+b$.
The ratio $$a:b$$ and the fraction $$a/b$$ are generally not synonymous and should not be treated as such, at least without making clear their interpretations. In many contexts, $$a:b$$ corresponds to the fraction $$a/(a+b)$$ or $$b/(a+b)$$.
For example, if one cuts a pizza into $$6$$ slices, one of which has anchovies, the fraction of slices with anchovies is $$1/6$$, while the ratio of slices with anchovies to slices without anchovies is $$1:5$$.
One context, unfortunately familiar to many students, where $$a/b$$ and $$a:b$$ are not synonyms is when speaking of odds in the context of bookmaking. That the odds be given by the ratio $$3:2$$ means roughly that the bookmaker expects the bet upon side to win $$2/5$$ times and the payout in the event of a win will be $$3/5$$ of the sum of the payout and money staked. That is when speaking of odds, the ratio $$a:b$$ corresponds to the fraction $$a/(a+b)$$ or $$b/(a+b)$$ (which form is relevant depends on interpretation/use). So $$9:1$$ odds against means that the horse is not expected to win, so the payout is big if it does, $$900$$ would be paid on a $$100$$ bet, while $$9:1$$ odds in favor (usually quoted as $$1:9$$) means that the horse is expected to win, and the payout is small if it does, approximately $$11 \simeq 100/9$$ would be paid on a $$100$$ bet.
• "In many contexts, 𝑎:𝑏 corresponds to the fraction 𝑎/(𝑎+𝑏) or 𝑏/(𝑎+𝑏)" — just don't call it ratio then. "the ratio of slices with anchovies to slices without anchovies is 1:5" — no, slices with anchovies correspond to slices without anchovies in proportion 1 to 5. People just use "ratio" because it is simpler to say than a "proportional relationship". Likewise, people use "rate" instead of "speed", then they wonder why kids don't understand what rate is. – Rusty Core Aug 30 '19 at 18:58
By itself, the word ratio is indeed rather opaque and should probably be avoided. Here is what "is under the hood and usually goes without saying".
Natural (aka counting) numbers are used to measure a "quantity" (= counting number) of discrete objects such as in: the "quantity" of the set {egg, egg, egg} is 3. What do we do when we want to measure a "quantity" (= real number) of continuous stuff such as length?
In terms of proportion, the ancient Greeks would have said that the "quantity" (length) of a footstick is to the "quantity" (length) of a yardstick the same as the "quantity" (count) of the set {egg}, i.e. 1, is to the "quantity" (count) of {egg, egg, egg}, i.e. 3. In terms of ratios, they would have said that the ratio of footstick to yardstick is equal to the ratio of {egg} to {egg, egg, egg}. When we say that the "quantity" of a footstick equals $\frac{1}{3}$ the "quantity" of a yardstick, we are just writing the proportion another way.
In other words, the idea of proportion was meant to reduce the measure of "quantity" of stuff (which they couldn't do) to the measure of "quantity" of sets (which they could do).
From my (by now very remote) experience with 5 graders, I think that the above distinction, measuring sets versus measuring continuous stuff (which, by the way, requires the introduction of units). is quite within their reach.
Warning: what follows may be a bit off-topic but is tightly related to the question.
The trouble comes when we want to look at a fraction as indicative of a measure the same way as when we look at a natural number as indicative of a measure. For instance, when we look at 3084385 and 47975 we immediately see that the first is larger than the second. Not so immediately with fractions.
So, of course, we look at $\frac{1}{3}$ as code for "divide 3 into 1" but the question now is "where to stop the division?" and that of course depends on the real-world situation. That we have rules for dealing with the code, e.g. $\frac{a}{b}\times\frac{c}{d}=\frac{ac}{bd}$ is nice and fortunate but not really necessary: as engineers are wont to put it, "The real real numbers are the decimal numbers".
See Gowers Mathematics, A Very Short Introduction. While spending a whole chapter (7) on infinite decimals, Gowers never even mentions real numbers. And, appropriately recast, the content of Gowers' Chapter 7 should be accessible to 5 grader.
First of all, I would leave out ratios entirely, if possible. They aren't as expressive as fractions are, and fractions are more widely used.
Why are ratios less expressive?
With (binary) ratios, you can compare only two things: $a:b$ (scores in a game, male-to-female distribution in the class, ...), while with fractions, you can have $a/x$, $b/x$, $c/x$, the fraction of several things from a larger group $x$ (color of hair, election results, ...).
Of course you could also do $a:b:c:...$, but I think that's too complicated?
How to explain the difference?
You could emphasize the difference in operations on both: adding ratios is simple, adding fractions is not. Multiplying fractions, or a fraction with a number makes sense, multiplying ratios doesn't. Another key is proper use of language to make clear what is being compared: The ratio of the number of one thing to another number of things, versus the fraction of a number of things of a total number of things.
• I don't think that $a:b:c$ is too complicated. It nicely points out the fact that ratios written this way aren't technically numbers. – DavidButlerUofA Jan 26 '15 at 0:06
• You can't leave out ratios altogether. For one thing, fractions are ratios. Rational numbers are numbers that can be expressed as ratios. The ratio a:b can be written as a/b. – Burt Furuta Jan 26 '15 at 20:10
Cooking examples work great here.
Rice is made with 1 part rice 2 parts water. The ratio is 1:2 rice:water. Or we can say 1/2 the water is the volume of rice to use. Or, as is often the case, you have an odd amount of rice, use twice that amount of water. I once saw my sister fill a 1 cup measure with rice, throw away the rest, and then add 2 cups of water. I asked why she threw out what looked like another 1/2 cup of rice. It wasn't enough for a "recipe". I don't know if she was a bad cook or bad at math, but she could have just measured 1-1/2 cups rice and double to 3 cups water to use.
We use 2:1 for Margarita's as well. 2 parts Mix to 1 part Tequila. Mix to Tequila is 2:1, and the final drink has 1/3 Tequila, 2/3 Margarita Mix.
It's key to understand that (ratio) 2:1 results in 3 parts of stuff, made up of (fraction) 1/3 one ingredient, 2/3 the other.
• I loved your example using cooking examples! Great job! Going to use it in my lesson. – user7088 Aug 28 '16 at 13:41
• 1 fresh squeeze lime juice : 1 orange liqueur (I prefer Cointreau, but Triple Sec is more traditional) : 2 tequila. On the rocks. Mix is teh debil (yes, "teh"; not "the"). :P – Xander Henderson Jul 25 '19 at 21:33
Ratio is just a single fraction. Whereas proportion is a ratio between 2 fractions.
Example - 5 boys and 3 girls in a class. Ratio of boys is 5/8 Ratio of girls is 3/8 But proportion of boys to girls is 5:3
The basic difference is Ratio is always with respect to some large quantities or superior quantities, whereas proportion is between same kind of quantities.
• I have never seen this distinction made. Out of curiosity, can you link to a source that does this? – Joonas Ilmavirta Apr 28 '16 at 14:01
• A proportion is an equation stating that there are two equal ratios 3:5=6:8. If you google "define proportion mathematically", you will find this definition and the definition on many math sites you used. – Amy B Apr 28 '16 at 14:21
• @AmyB "A proportion is an equation stating that there are two equal ratios 3:5=6:8" — Indeed. The problem is, these two particular ratios are not equal ;-) – Rusty Core Jul 23 '19 at 23:39
• @RustyCore It shouldn't have taken 2 years for someone to notice that! I tried to edit but wasn't able to so I will rephrase: A proportion is an equation stating that there are 2 equal ratios 3:5=6:10. If you google "define proportion mathematically" you will find this definition on many math sites. – Amy B Jul 25 '19 at 5:33
Relation between division and fraction have to be understood to understand the relationship between fraction and ratio: 1. Division: finding how many times of divisor in the dividend, or the value of a part 1/5 means 5 is 0.20 times in 1; value of one part is 0.20. 2. Fraction: It is how many times the denominator in numerator or how many parts of denominator in numerator. It means multiplying the value of one part with numerator: 2/5 = 1/5 X 2 = 0.40 3 Ratio: Ratio is a division finding how many times one entity in to other. And it is a fraction for one in numerator. 4. All are written in fraction form with same value
Division and Fractions have applications in daily life where as ratio being an another form of division and fraction does not find place in daily life applications. Therefore ratio is not an independent entity but a name to refer how many times in a division in context. Probably it is good idea not to teach ratio as an independent entity. Therefore ratio is an application of fractions like percentage, rebate, loss and profit. They all use the properties of equivalent fractions. Proportion too is an equivalent fraction.
There are several possible fractions one could associate with a given ratio.
Say that a recipe for lemonade calls for $$2$$ cups of lemon juice and $$5$$ cups of water. This could be expressed with the ratio $$2:5$$. Here are some different associated fractions:
1. $$2/7$$ of the lemonade is lemon juice.
2. $$5/7$$ of the lemonade is water.
3. $$2/5$$ of a cup of lemon juice is the amount which needs to be added to 1 cup of water.
4. $$5/2$$ of a cup of water is the amount which needs to be added to 1 cup of lemon juice.
I don't think any of these fractions has a right to be called "the fraction" associated with the ratio.
Some additional evidence that ratio and fraction are distinct concepts:
The ratios 0:5 and 5:0 both make sense. For instance, you could have 0 parts lemon juice to 5 parts water.
One can have ratios between more than 2 quantities. The ratio 1:2:5, as in 1 part sugar, 2 parts lemon juice, and 5 parts water makes perfect sense. This ratio would be equivalent to 2:4:10 (since the proportions are the same), but there is no single associated fraction.
For a mathematical definition one could use the following:
An ratio of $$n$$ quantities is an equivalence class of elements of $$\mathbb{R}^n-\{\mathbf{0}\}$$ under the equivalence relation $$\mathbf{v} \sim \mathbf{w}$$ iff there exists a $$c \in \mathbb{R}-\{0\}$$ such that $$\mathbf{v} = c \mathbf{w}$$.
In other words, ratios are just elements of real projective spaces!
I'm not sure how you would translate the following into the language of 10-year-olds, but the teacher should first understand this much:
The variables x and y are respectively in the ratio a:b means only that x/y = a/b (for non-zero values of a, b, x and y).
Similarly, the variables x, y and z are respectively in the ratio of a:b:c means only that x/y = a/b and y/z =b/c (for non-zero values of a, b, c, x, y and z).
Above while representing ratio in a flow diagram above one branch is represented by part/part. There is no such concept as part/part in fraction form. The denominator is always a 'whole'. While comparing two items one of them should be taken as whole and other as part of the whole.
The diagram in the present form violates the fundamental principle of fraction.
• I don't understand why fractions cannot be used to describe part/part relations. For example, in the flow chart, 13 boys and 11 girls is represented by the ratio $13 : 11$. As a fraction, you may regard this as either $$\frac{13}{11} \qquad\text{or}\qquad \frac{13/T}{11/T} = \frac{13/24}{11/24},$$ where $T$ is the total number of students (which is $24$, hence the second expression). – Xander Henderson Jul 25 '19 at 21:37
• @XanderHenderson I do not see the meaning of the fraction $13/11$ in this context. It could mean something like For every 1 girl, there is $13/11$ of a boy'', but that is awkward. – Steven Gubkin Aug 27 '19 at 12:18
• Or... for every 13 boys, there are 11 girls. This seems to be a question of dimensional analysis, which was taught in my high school chemistry and physics classes. For example: there are approximately 3.3 feet per meter, so we can use the conversion factor $$\frac{33 \ \text{feet}}{10\ \text{meters}}$$ to convert from meters to feet. We could also use $3.3\ \text{feet}/\text{meter}$, but working with whole numbers is sometimes easier. – Xander Henderson Aug 27 '19 at 13:25
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https://www.nist.gov/pml/special-publication-811/nist-guide-si-chapter-10-more-printing-and-using-symbols-and-numbers
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# NIST Guide to the SI, Chapter 10: More on Printing and Using Symbols and Numbers in Scientific and Technical Documents
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By following the guidance given in this chapter, NIST authors can prepare manuscripts that are consistent with accepted typesetting practice.
10.1 Kinds of symbols
Letter symbols are of three principal kinds: (a) symbols for quantities, (b) symbols for units, and (c) symbols for descriptive terms. Quantity symbols, which are always printed in italic (that is, sloping) type, are, with few exceptions, single letters of the Latin or Greek alphabets that may have subscripts or superscripts or other identifying signs. Symbols for units, in particular those for acceptable units, have been discussed in detail in earlier portions of this Guide. Symbols for descriptive terms include the symbols for the chemical elements, certain mathematical symbols, and modifying superscripts and subscripts on quantity symbols.
10.1.1 Standardized quantity symbols
The use of words, acronyms, or other ad hoc groups of letters as quantity symbols should be avoided by NIST authors. For example, use the quantity symbol Zm for mechanical impedance, not MI. In fact, there are nationally and internationally accepted symbols for literally hundreds of quantities used in the physical sciences and technology. Many of these are given in Refs. [4] and [5], and it is likely that symbols for the quantities used in most NIST publications can be found in these international standards or can readily be adapted from the symbols and principles given in these standards. Because of their international acceptance, NIST authors are urged to use the symbols of Refs. [4] and [5] to the fullest extent possible.5
Examples:
Ω (solid angle) Zm (mechanical impedance) LP (level of a power quantity) Δr (relative mass excess) p (pressure) σtot (total cross section) κT (isothermal compressibility) Eu (Euler number) E (electric field strength) TN (Néel temperature)
10.1.2 Standardized mathematical signs and symbols
As is the case for quantity symbols, most of the mathematical signs and symbols used in the physical sciences and technology are standardized. They may be found in Ref. [4: ISO 31-11] and should be used by NIST authors to the fullest possible extent.5
Examples:
^ (conjunction sign, p ^ q means p and q) ≠ (a ≠ b, a is not equal to b) ( a b, a is by definition equal to b) ≈ (a ≈ b, a is approximately equal to b) ~ (a ~ b, a is proportionally equal to b) arcsin x (arc sine of x) logax (logarithm to the base a of x) lb x (lb x = log2x) ln x (ln x = logex) lg x (lg x = log10x)
10.2 Typefaces for symbols
Most word processing systems now in use at NIST are capable of producing lightface (that is, regular) or boldface letters of the Latin or Greek alphabets in both roman (upright) and italic (sloping) types. The understandability of NIST typed and typeset scientific and technical publications is facilitated if symbols are in the correct typeface. The typeface in which a symbol appears helps to define what the symbol represents. For example, irrespective of the typeface used in the surrounding text, "A" would be typed or typeset in:
— italic type for the scalar quantity area: A;
— roman type for the unit ampere: A;
— italic boldface for the vector quantity vector potential: A.
More specifically, the three major categories of symbols found in scientific and technical publications should be typed or typeset in either italic or roman type, as follows:
—symbols for quantities and variables: italic;
—symbols for units: roman;
—symbols for descriptive terms: roman.
These rules imply that a subscript or superscript on a quantity symbol is in roman type if it is descriptive (for example, if it is a number or represents the name of a person or a particle); but it is in italic type if it represents a quantity, or is a variable such as x in Ex or an index such as i in ∑ixi that represents a number (see Secs. 10.2.1, 10.2.3, and 10.2.4). An index that represents a number is also called a "running number" [4: ISO 31-0]
Notes:
1. The above rules also imply, for example, that μ, the symbol for the SI prefix micro (10-6), that Ω, the symbol for the SI derived unit ohm, and that F, the symbol for the SI derived unit farad, are in roman type; but they are in italic type if they represent quantities (μ, Ω, and F are the recommended symbols for the quantities magnetic moment of a particle, solid angle, and force, respectively).
2. The typeface for numbers is discussed in Sec. 10.5.1. The following four sections give examples of the proper typefaces for these three major categories.
10.2.1 Quantities and variables — italic
Symbols for quantities are italic, as are symbols for functions in general, for example, f (x):
t = 3s time, s second T = 22 K T temperature, K kelvin r = 11 cm r radius, cm centimeter λ = 633 nm λ wavelength, nm nanometer
Constants are usually physical quantities and thus their symbols are italic; however, in general, symbols used as subscripts and superscripts are roman if descriptive (see Sec. 10.2.3):
NA Avogadro constant, A Avogadro R molar gas constant θD Debye temperature, D Debye Z atomic number e elementary charge me m mass, e electron
Running numbers and symbols for variables in mathematical nist-equations are italic, as are symbols for parameters such as a and b that may be considered constant in a given context:
Symbols for vectors are boldface italic, symbols for tensors are sans-serif bold italic, and symbols for matrices are italic:
A·B = C (vectors) T (tensors)
Symbols used as subscripts and superscripts are italic if they represent quantities or variables:
Cpp pressure qmm mass σΩ Ω solid angle ω zz z coordinate
10.2.2 Units— roman
The symbols for units and SI prefixes are roman:
m meter g gram L liter cm centimeter μg centimeter mL milliliter
10.2.3 Descriptive terms — roman
Symbols representing purely descriptive terms (for example, the chemical elements) are roman, as are symbols representing mathematical constants that never change (for example, π) and symbols representing explicitly defined functions or well defined operators (for example, Γ(x) or div): Chemical elements:
Ar argon B boron C carbon
Mathematical constants, functions, and operators:
e base of natural logarithms Σxi Σ sum of exp x exp exponential of logax loga logarithm to the base a of dx/dt d 1st derivative of sin x sin sine of
Symbols used as subscripts and superscripts are roman if descriptive:
ε0(ir) ir irrational Ek k kinetic V1m m molar, l liquid phase μB B Bohr
10.2.4 Sample nist-equations showing correct type
$$F = \frac{q_1 q_2}{4\pi \varepsilon_0 r^2}$$ F = ma pV = nRT $$\varphi_{\rm B} = x_{\rm B} V_{\rm m,B}^* /\sum x_{\rm A} V_{\rm m,A}^*$$ Ea = RT2 d(ln k)/dT $$c_1 = \lambda^{-5} / [\exp(c_2/\lambda T) - 1]$$ E = mc2 $$\tilde{p}_{\rm B} = \lambda_{\rm B} \lim_{p\rightarrow0} (x_{\rm B} p/\lambda_{\rm B})$$ $$\frac{F}{Q} = - {\bf grad} \, V$$
10.3 Greek alphabet in roman and italic type
Table 13 shows the proper form, in both roman and italic type, of the upper-case and lower-case letters of the Greek alphabet.
### Table 13. Greek alphabet in roman and italic type
Some browsers may not display this table as author intended. If in doubt please use the pdf version.
NameCapital
Roman
Lower Case
Roman
Capital
Italic
Lower Case
Italic
alphaAαAα
betaBβBβ
gammaΓγΓγ
deltaΔδΔδ
epsilonEεEε,ε
zetaZζZζ
etaHηHη
thetaΘ, Ө(a)θ,
(b)
Θ, Ө(a)θ,
(b)
iotaIιIι
kappaKκ, κ(b)Kκ, κ(b)
lambdaΛλΛλ
muMµMµ
nuNνNν
xiΞξΞξ
omicronOoOo
piΠπ,
Ππ,
rhoPρ, ρ(b)Pρ, ρ(b)
sigmaΣσΣσ
tauTτTτ
upsilonΥυΥυ
phiΦφ,φΦφ,φ
chiXχXχ
psiΨψΨψ
omegaΩωΩω
(a) ISO (see Ref. [4: ISO 31-0]) gives only the first of these two letters.
(b) ISO (see Ref. [4: ISO 31-0]) gives these two letters in the reverse order.
10.4 Symbols for the elements
The following two sections give the rules and style conventions for the symbols for the elements.
10.4.1 Typeface and punctuation for element symbols
Symbols for the elements are normally printed in roman type without regard to the type used in the surrounding text (see Sec. 10.2.3). They are not followed by a period unless at the end of a sentence.
10.4.2 Subscripts and superscripts on element symbols
The nucleon number (mass number) of a nuclide is indicated in the left superscript position: 28Si.
The number of atoms in a molecule of a particular nuclide is shown in the right subscript
position: 1H2. The proton number (atomic number) is indicated in the left subscript position: 29Cu.
The state of ionization or excitation is indicated in the right superscript position, some examples of which are as follows:
State of ionization: Ba++
Co(NO2)6--- or Co(NO2 )36- or [Co(NO2)6]3-
Electronic excited state: Ne*, CO*
Nuclear excited state: 15N* or 15Nm
10.5 Printing numbers
The following three sections give rules and style conventions related to the printing of numbers.
10.5.1 Typeface for numbers
Arabic numerals expressing the numerical values of quantities (see Sec. 7.6) are generally printed in lightface (that is, regular) roman type irrespective of the type used for the surrounding text. Arabic numerals other than numerical values of quantities may be printed in lightface or bold italics, or in bold roman type, but lightface roman type is usually preferred.
10.5.2 Decimal sign or marker
The recommended decimal sign or marker for use in the United States is the dot on the line [3, 6]. For numbers less than one, a zero is written before the decimal marker. For example, 0.25 s is the correct form, not .25 s.
10.5.3 Grouping digits
Because the comma is widely used as the decimal marker outside the United States, it should not be used to separate digits into groups of three. Instead, digits should be separated into groups of three, counting from the decimal marker towards the left and right, by the use of a thin, fixed space. However, this practice is not usually followed for numbers having only four digits on either side of the decimal marker except when uniformity in a table is desired.
Examples:
76 483 522 but not: 76,483,522 43 279.168 29 but not: 43,279.168 29 8012 or 8 012 but not: 8,012 0.491 722 3 is highly preferred to: 0.4917223 0.5947 or 0.594 7 but not: 0.59 47 8012.5947 or 8 012.594 7 but not: 8 012.5947 or 8012.594 7
Note: The practice of using a space to group digits is not usually followed in certain specialized applications, such as engineering drawings and financial statements.
10.5.4 Multiplying numbers
When the dot is used as the decimal marker as in the United States, the preferred sign for the multiplication of numbers or values of quantities is a cross (that is, multiplication sign) (×), not a half-high (that is, centered) dot (·).
Examples:
25 × 60.5 but not: 25·60.5 53 m/s × 10.2 s but not: 53 m/s·10.2 s 15 × 72 kg but not: 15·72 kg
Notes:
1. When the comma is used as the decimal marker, the preferred sign for the multiplication of numbers is the half-high dot. However, even when the comma is so used, this Guide prefers the cross for the multiplication of values of quantities.
2. The multiplication of quantity symbols (or numbers in parentheses or values of quantities in parentheses) may be indicated in one of the following ways: ab, a b, a·b, a × b.
Created January 28, 2016, Updated September 7, 2016
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