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Nickel bronze Toxicity Nickel_bronze > Toxicity According to the Merck Manual, prolonged contact of copper alloys with acidic food or beverages (including boiling milk) can leach out the copper and cause toxicity. Long-term, low doses can lead to cirrhosis. It is also the case that many people have allergic reactions to nickel, causing a weeping rash that will not heal as long as the metal is in contact with the skin.
Diagnostic fast Autoimmune hypoglycemia Diagnostic_fast > Causes > Non-diabetics > Autoimmune hypoglycemia In one instance, antibodies bind to insulin following its release associated with a meal, resulting in insulin being non-functional. At a later time, the antibodies fall off insulin, causing insulin to be functional again leading late hypoglycemia after a meal, called late postprandial hypoglycemia. Another mechanism causing hypoglycemia is due to antibodies formed against insulin receptors, called insulin receptor antibodies. The antibodies attach to insulin receptors and prevent insulin breakdown, or degradation, leading to inappropriately high insulin levels and low glucose levels.
Genome editing with engineered nucleases Prospects and limitations Risks_of_genome_editing > Prospects and limitations In the future, a possible method to identify secondary targets would be to capture broken ends from cells expressing the ZFNs and to sequence the flanking DNA using high-throughput sequencing.Because of the ease of use and cost-efficiency of CRISPR, extensive research is currently being done on it. There are now more publications on CRISPR than ZFN and TALEN despite how recent the discovery of CRISPR is. Both CRISPR and TALEN are favored to be the choices to be implemented in large-scale productions due to their precision and efficiency.
Di-haem cytochrome c peroxidase Summary Di-haem_cytochrome_c_peroxidase In molecular biology, the di-haem cytochrome c peroxidase family is a group of distinct cytochrome c peroxidases (CCPs) that contain two haem groups. Similar to other cytochrome c peroxidases, they reduce hydrogen peroxide to water using c-type haem as an oxidizable substrate. However, since they possess two, instead of one, haem prosthetic groups, this family of bacterial CCPs reduce hydrogen peroxide without the need to generate semi-stable free radicals. The two haem groups have significantly different redox potentials.
Probabilistic classifier Generative and conditional training Probabilistic_classification > Generative and conditional training Some models, such as logistic regression, are conditionally trained: they optimize the conditional probability Pr ( Y \| X ) {\displaystyle \Pr(Y\vert X)} directly on a training set (see empirical risk minimization). Other classifiers, such as naive Bayes, are trained generatively: at training time, the class-conditional distribution Pr ( X \| Y ) {\displaystyle \Pr(X\vert Y)} and the class prior Pr ( Y ) {\displaystyle \Pr(Y)} are found, and the conditional distribution Pr ( Y \| X ) {\displaystyle \Pr(Y\vert X)} is derived using Bayes' rule. : 43
NMR line broadening techniques Determining bond rotational energies NMR_line_broadening_techniques > Determining bond rotational energies A basic NMR line broadening experiment is to determine the rotational energy barrier of a certain chemical bond. If the bond rotates slowly enough compared to the NMR time scale (e.g., amide bond), two different species can be detected by the NMR spectrometer. Considering that the time scale of NMR spectroscopy is about a few seconds, this technique can be used to examine the kinetics and/or thermodynamics of chemical exchange reactions on the order of seconds. In general, the energy barrier to rotate a bond is low enough at room temperature, which means that the rotation is fast, making the two different species indistinguishable.
Skew gears Skew gears Helical_gear > Types > Helical > Skew gears For a "crossed" or "skew" configuration, the gears must have the same pressure angle and normal pitch; however, the helix angle and handedness can be different. The relationship between the two shafts is actually defined by the helix angle(s) of the two shafts and the handedness, as defined: E = β 1 + β 2 {\displaystyle E=\beta _{1}+\beta _{2}} for gears of the same handedness, E = β 1 − β 2 {\displaystyle E=\beta _{1}-\beta _{2}} for gears of opposite handedness,where β {\displaystyle \beta } is the helix angle for the gear. The crossed configuration is less mechanically sound because there is only a point contact between the gears, whereas in the parallel configuration there is a line contact.Quite commonly, helical gears are used with the helix angle of one having the negative of the helix angle of the other; such a pair might also be referred to as having a right-handed helix and a left-handed helix of equal angles. The two equal but opposite angles add to zero: the angle between shafts is zero—that is, the shafts are parallel.
Near-infrared light ISO 20473 scheme Infrared_rays > Regions within the infrared > ISO 20473 scheme ISO 20473 specifies the following scheme:
Earthquake rotational loading Summary Earthquake_rotational_loading In a recent study, the combined action of the rotational loading and multi-support excitation on the seismic behavior of short-span bridges was investigated. The numerical results suggested that depending on structure properties and excitation characteristics, rotational components decrease beneficial effects of multi-support excitation on the structure response.
List of measuring instruments Uncategorized, specialized, or generalized application List_of_measuring_instruments > Uncategorized, specialized, or generalized application Actograph measures and records animal activity within an experimental chamber. Densitometer measures light transmission through processed photographic film or transparent material or light reflection from a reflective material. Force platform measures ground reaction force. Gauge (engineering) A highly precise measurement instrument, also usable to calibrate other instruments of the same kind.
Facet theory Complementary topics in partial order spaces Facet_theory > Multiple scaling by POSAC > Complementary topics in partial order spaces Higher order partition lines. The above simple measurement space illustrates partition-lines that are straight or have one bend. More complex measurement spaces result with items whose partition-lines have two or more bends.While partial order spaces are used mainly for analyzing score profiles (based on range facets), under certain conditions, they may be applied to the analysis of content profiles; i.e., those based on content facets.Relating POSAC Measurement Space to the SSA Concept Space.
The Internet of Things Organizations The_Internet_of_Things > Applications > Organizations The term "Enterprise IoT" refers to devices used in business and corporate settings. By 2019, it is estimated that the EIoT will account for 9.1 billion devices.
Multi-agent systems Concept Multi-agent_systems > Concept Agents can be divided into types spanning simple to complex. Categories include: Passive agents or "agent without goals" (such as obstacle, apple or key in any simple simulation) Active agents with simple goals (like birds in flocking, or wolf–sheep in prey-predator model) Cognitive agents (complex calculations)Agent environments can be divided into: Virtual Discrete ContinuousAgent environments can also be organized according to properties such as accessibility (whether it is possible to gather complete information about the environment), determinism (whether an action causes a definite effect), dynamics (how many entities influence the environment in the moment), discreteness (whether the number of possible actions in the environment is finite), episodicity (whether agent actions in certain time periods influence other periods), and dimensionality (whether spatial characteristics are important factors of the environment and the agent considers space in its decision making). Agent actions are typically mediated via an appropriate middleware. This middleware offers a first-class design abstraction for multi-agent systems, providing means to govern resource access and agent coordination.
Mosco convergence Definition Mosco_convergence > Definition Let X be a topological vector space and let X∗ denote the dual space of continuous linear functionals on X. Let Fn: X → be functionals on X for each n = 1, 2, ... The sequence (or, more generally, net) (Fn) is said to Mosco converge to another functional F: X → if the following two conditions hold: lower bound inequality: for each sequence of elements xn ∈ X converging weakly to x ∈ X, lim inf n → ∞ F n ( x n ) ≥ F ( x ) ; {\displaystyle \liminf _{n\to \infty }F_{n}(x_{n})\geq F(x);} upper bound inequality: for every x ∈ X there exists an approximating sequence of elements xn ∈ X, converging strongly to x, such that lim sup n → ∞ F n ( x n ) ≤ F ( x ) . {\displaystyle \limsup _{n\to \infty }F_{n}(x_{n})\leq F(x).} Since lower and upper bound inequalities of this type are used in the definition of Γ-convergence, Mosco convergence is sometimes phrased as “weak Γ-liminf and strong Γ-limsup” convergence. Mosco convergence is sometimes abbreviated to M-convergence and denoted by M-lim n → ∞ ⁡ F n = F or F n → n → ∞ M F . {\displaystyle \mathop {\text{M-lim}} _{n\to \infty }F_{n}=F{\text{ or }}F_{n}{\xrightarrow{\mathrm {M} }}F.}
Matrix (protocol) Adoption Matrix_(communication_protocol) > Adoption Rocket.Chat is based on Matrix since version 4.7.0. It is used in private networks of public governmental offices, private companies and NGOs, across the world. The FOSDEM was held on Matrix in 2021 and 2022. The hosting was provided by Element Matrix Services, which published the technical details for public review soon after the event for 2021 and 2022.
Dataveillance Cons Dataveillance > Benefits and concerns > Cons Much of an individual's data is shared with websites and social networks in order to provide a more customized marketing experience. Many of those social networks may share your information with intelligence agencies and authorities, without a user's knowledge. Since the recent scandal involving Edward Snowden and National Security Agency, it has been revealed that authorities may have access to more data from various devices and platforms.
Prodiscrete topology Q Punctured_plane > Q Note that this does not imply that f is an open function.Quotient space If X is a space, Y is a set, and f: X → Y is any surjective function, then the Quotient topology on Y induced by f is the finest topology for which f is continuous. The space X is a quotient space or identification space. By definition, f is a quotient map. The most common example of this is to consider an equivalence relation on X, with Y the set of equivalence classes and f the natural projection map. This construction is dual to the construction of the subspace topology.
Threaded code Lesser-used threading Threaded_code > Threading models > Lesser-used threading An example is string threading, in which operations are identified by strings, usually looked up by a hash table. This was used in Charles H. Moore's earliest Forth implementations and in the University of Illinois's experimental hardware-interpreted computer language. It is also used in Bashforth.
Fuel control unit Types of fuel control units Fuel_control_unit > Types of fuel control units Hydromechanical: A combination of a flyweight governor and several sensors including compressor discharge pressure, burner can pressure, and exhaust pipe pressure. In some cases the engine's fuel pump is integrated in to the fuel control. Electronic engine control (EEC): An EEC is essentially a hydromechanical fuel control but with added electrical components to prevent overheating or overspeeding the engine. If the electrical part of the control should fail, an EEC will revert to a standard hydromechanical fuel control. Full-authority digital engine control (FADEC): A digital computer which controls a servo-operated fuel valve. In this case the power lever is only electrically connected to the fuel control.
Fortran FORTRAN II Fortran > Evolution > FORTRAN II Early FORTRAN compilers supported no recursion in subroutines. Early computer architectures supported no concept of a stack, and when they did directly support subroutine calls, the return location was often stored in one fixed location adjacent to the subroutine code (e.g. the IBM 1130) or a specific machine register (IBM 360 et seq), which only allows recursion if a stack is maintained by software and the return address is stored on the stack before the call is made and restored after the call returns. Although not specified in FORTRAN 77, many F77 compilers supported recursion as an option, and the Burroughs mainframes, designed with recursion built-in, did so by default. It became a standard in Fortran 90 via the new keyword RECURSIVE.
Nucleophilic acyl substitution Esters Nucleophilic_acyl_substitution > Reactions of acyl derivatives > Esters Unfortunately, because the leaving group is also an alcohol, the forward and reverse reactions will often occur at similar rates. Using a large excess of the reactant alcohol or removing the leaving group alcohol (e.g. via distillation) will drive the forward reaction towards completion, in accordance with Le Chatelier's principle.Acid-catalyzed hydrolysis of esters is also an equilibrium process – essentially the reverse of the Fischer esterification reaction. Because an alcohol (which acts as the leaving group) and water (which acts as the nucleophile) have similar pKa values, the forward and reverse reactions compete with each other.
Economics of information Papers Economics_of_information > Further reading > Papers Chapters 13 and 14 discuss applications of adverse selection and moral hazard models to contract theory. Milgrom, Paul R., 1981. "Good News and Bad News: Representation Theorems and Applications," Bell Journal of Economics, 12(2), pp.
Infinite string Analysis Bi-infinite_string > Use in other fields of mathematics > Analysis When talking about such infinite sequences, it is usually sufficient (and does not change much for most considerations) to assume that the members of the sequence are defined at least for all indices large enough, that is, greater than some given N. The most elementary type of sequences are numerical ones, that is, sequences of real or complex numbers. This type can be generalized to sequences of elements of some vector space. In analysis, the vector spaces considered are often function spaces. Even more generally, one can study sequences with elements in some topological space.
Protocol Buffers Summary Protocol_Buffers Protocol Buffers (Protobuf) is a free and open-source cross-platform data format used to serialize structured data. It is useful in developing programs that communicate with each other over a network or for storing data. The method involves an interface description language that describes the structure of some data and a program that generates source code from that description for generating or parsing a stream of bytes that represents the structured data.
Binary variable Mathematical and combinatoric foundations Binary_variable > Mathematical and combinatoric foundations Moreover, Boolean algebra provides a convenient mathematical structure for collection of bits, with a semantic of a collection of propositional variables. Boolean algebra operations are known as "bitwise operations" in computer science. Boolean functions are also well-studied theoretically and easily implementable, either with computer programs or by so-named logic gates in digital electronics. This contributes to the use of bits to represent different data, even those originally not binary.
Industrial water treatment Cooling water treatment Industrial_water_treatment > Processes > Cooling water treatment Water cooling is a method of heat removal from components of machinery and industrial equipment. Water may be a more efficient heat transfer fluid where air cooling is ineffective. In most occupied climates water offers the thermal conductivity advantages of a liquid with unusually high specific heat capacity and the option that of evaporative cooling. Low cost often allows rejection as waste after a single use, but recycling coolant loops may be pressurized to eliminate evaporative loss and offer greater portability and improved cleanliness.
Undeniable signature Summary Undeniable_signature An undeniable signature is a digital signature scheme which allows the signer to be selective to whom they allow to verify signatures. The scheme adds explicit signature repudiation, preventing a signer later refusing to verify a signature by omission; a situation that would devalue the signature in the eyes of the verifier. It was invented by David Chaum and Hans van Antwerpen in 1989.
Optimal Control Theory Examples Optimal_Control_Theory > Examples Having obtained λ ( t ) {\displaystyle \lambda (t)} , the turn-t optimal value for the control can usually be solved as a differential equation conditional on knowledge of λ ( t ) {\displaystyle \lambda (t)} . Again it is infrequent, especially in continuous-time problems, that one obtains the value of the control or the state explicitly. Usually, the strategy is to solve for thresholds and regions that characterize the optimal control and use a numerical solver to isolate the actual choice values in time.
Rainbow option Summary Rainbow_option Rainbow option is a derivative exposed to two or more sources of uncertainty, as opposed to a simple option that is exposed to one source of uncertainty, such as the price of underlying asset. The name of rainbow comes from Rubinstein (1991), who emphasises that this option was based on a combination of various assets like a rainbow is a combination of various colors. More generally, rainbow options are multiasset options, also referred to as correlation options, or basket options.
V-Model (software development) Criticism V-Model_(software_development) > Criticism It implicitly promotes writing test scripts in advance rather than exploratory testing; it encourages testers to look for what they expect to find, rather than discover what is truly there. It also encourages a rigid link between the equivalent levels of either leg (e.g. user acceptance test plans being derived from user requirements documents), rather than encouraging testers to select the most effective and efficient way to plan and execute testing.
Conic section Matrix notation Directrix_of_a_conic_section > Euclidean geometry > General Cartesian form > Matrix notation The above equation can be written in matrix notation as The general equation can also be written as This form is a specialization of the homogeneous form used in the more general setting of projective geometry (see below).
Third man argument Discussion with Aristoteles Third_man_argument > Discussion with Aristoteles It cannot change because it has no parts to change. If it moves position it moves either circularly or linearly. If it spins in place its outer part revolves around its middle but the one has neither.
Technology stack Summary Solution_stack Another version of a software stack is operating system, middleware, database, and applications. Regularly, the components of a software stack are developed by different developers independently from one another. Some components/subsystems of an overall system are chosen together often enough that the particular set is referred to by a name representing the whole, rather than by naming the parts.
Rotary converter plant Summary Rotary_converter_plant At each facility, power from an AC power grid was converted to DC to feed into an overhead line or a third rail of a railway. Rotary converter plants were also used for coupling power grids of different frequencies and operation modes. The former Neuhof Substation was an example of the latter.
History of software engineering Languages History_of_software_engineering > Sub-disciplines > Artificial intelligence > Languages Early symbolic AI inspired Lisp and Prolog, which dominated early AI programming. Modern AI development often uses mainstream languages such as Python or C++, or niche languages such as Wolfram Language.
Jacobian of a curve Computation techniques Jacobian_varieties > References > Computation techniques doi:10.1007/BF02599319. S2CID 122944746. Anderson, Greg W.
Order of magnitude (numbers) 1027 Order_of_magnitude_(numbers) > 1027 (1000000000000000000000000000; 10009; short scale: one octillion; long scale: one thousand quadrillion, or one quadrilliard) ISO: ronna- (R) Biology – Atoms in the human body: the average human body contains roughly 7×1027 atoms. Mathematics – Poker: the number of unique combinations of hands and shared cards in a 10-player game of Texas hold 'em is approximately 2.117×1028.
Burnishing (metal) Failure mode (unintentionally) Burnishing_(metal) > Failure mode (unintentionally) Even the smoothest of surfaces will have imperfections if viewed at a high enough magnification. The imperfections that extend above the general form of a surface are called asperities, and they can plow material on another surface just like the ball dragging along the plate. The combined effect of many of these asperities produce the smeared texture that is associated with burnishing.
Generative model Contrast with discriminative classifiers Generative_model > Contrast with discriminative classifiers On the other hand, it has been proved that some discriminative algorithms give better performance than some generative algorithms in classification tasks.Despite the fact that discriminative models do not need to model the distribution of the observed variables, they cannot generally express complex relationships between the observed and target variables. But in general, they don't necessarily perform better than generative models at classification and regression tasks. The two classes are seen as complementary or as different views of the same procedure.
Isospin The introduction of quarks Isospin > History > The introduction of quarks The discovery and subsequent analysis of additional particles, both mesons and baryons, made it clear that the concept of isospin symmetry could be broadened to an even larger symmetry group, now called flavor symmetry. Once the kaons and their property of strangeness became better understood, it started to become clear that these, too, seemed to be a part of an enlarged symmetry that contained isospin as a subgroup. The larger symmetry was named the Eightfold Way by Murray Gell-Mann, and was promptly recognized to correspond to the adjoint representation of SU(3).
Dollar sign Programming languages Peso_sign > Use in computer software > Programming languages In an AutoHotkey script, a hotkey declared with $ is not triggered by a 'Send' command elsewhere in the script. In several JavaScript frameworks such as Prototype.js and jQuery, $ is a common utility class, and is often referred to as the buck.
Stationary points Example Stationary_points > Curve sketching > Example For the function f(x) = x4 we have f′(0) = 0 and f″(0) = 0. Even though f″(0) = 0, this point is not a point of inflection. The reason is that the sign of f′(x) changes from negative to positive. For the function f(x) = sin(x) we have f′(0) ≠ 0 and f″(0) = 0.
Nondeterministic finite automata Recognized language Nondeterministic_finite-state_automaton > Formal definition > Recognized language The set of strings M {\displaystyle M} accepts is the language recognized by M {\displaystyle M} and this language is denoted by L ( M ) {\displaystyle L(M)} . : 320: 54 Alternatively, w {\displaystyle w} is accepted if δ ∗ ( q 0 , w ) ∩ F ≠ ∅ {\displaystyle \delta ^{}(q_{0},w)\cap F\not =\emptyset } , where δ ∗: Q × Σ ∗ → P ( Q ) {\displaystyle \delta ^{}:Q\times \Sigma ^{}\rightarrow {\mathcal {P}}(Q)} is defined recursively by: δ ∗ ( r , ϵ ) = { r } {\displaystyle \delta ^{}(r,\epsilon )=\{r\}} where ϵ {\displaystyle \epsilon } is the empty string, and δ ∗ ( r , x a ) = ⋃ r ′ ∈ δ ∗ ( r , x ) δ ( r ′ , a ) {\displaystyle \delta ^{}(r,xa)=\bigcup _{r'\in \delta ^{}(r,x)}\delta (r',a)} for all x ∈ Σ ∗ , a ∈ Σ {\displaystyle x\in \Sigma ^{},a\in \Sigma } .In words, δ ∗ ( r , x ) {\displaystyle \delta ^{}(r,x)} is the set of all states reachable from state r {\displaystyle r} by consuming the string x {\displaystyle x} . The string w {\displaystyle w} is accepted if some accepting state in F {\displaystyle F} can be reached from the start state q 0 {\displaystyle q_{0}} by consuming w {\displaystyle w} . : 21: 59
Crystal field stabilization energy Overview Crystal_field_stabilization_energy > Overview Thus the d-electrons closer to the ligands will have a higher energy than those further away which results in the d-orbitals splitting in energy. This splitting is affected by the following factors: the nature of the metal ion. the metal's oxidation state.
Multiplet Quantum field theory Multiplet > Physics > Quantum field theory For example a scalar field ϕ ( x ) {\displaystyle \phi (x)} , where x {\displaystyle x} is a spacetime point, might have an isospin state taking values in the fundamental representation C 2 {\displaystyle \mathbb {C} ^{2}} of SU ( 2 ) {\displaystyle {\text{SU}}(2)} . Then ϕ ( x ) {\displaystyle \phi (x)} is a vector valued function of spacetime, but is still referred to as a scalar field, as it transforms trivially under Lorentz transformations. In quantum field theory different particles correspond one to one with gauged fields transforming in irreducible representations of the internal and Lorentz group. Thus, a multiplet has also come to describe a collection of subatomic particles described by these representations.
Michelson–Morley experiment Observer resting in the aether Michelson-Morley_experiment > Light path analysis and consequences > Observer resting in the aether At this time, the mirror has traveled the distance v T 1 {\textstyle vT_{1}} . Thus c T 1 = L + v T 1 {\textstyle cT_{1}=L+vT_{1}} and consequently the travel time T 1 = L / ( c − v ) {\textstyle T_{1}=L/(c-v)} . The same consideration applies to the backward journey, with the sign of v {\textstyle v} reversed, resulting in c T 2 = L − v T 2 {\textstyle cT_{2}=L-vT_{2}} and T 2 = L / ( c + v ) {\textstyle T_{2}=L/(c+v)} .
Public choice Modern public choice theory Public_choice > Background and development > Modern public choice theory In a series of papers from 1948, which culminated in The Theory of Committees and Elections (1958), and later, Black outlined a program of unification toward a more general "Theory of Economic and Political Choices" based on common formal methods, developed underlying concepts of what would become median voter theory, and rediscovered earlier works on voting theory. Black's work also included the possibility of entirely random outcomes in a voting structure, where the only governance over the outcome is the where a particular motion falls in the sequence presented.Kenneth J. Arrow's Social Choice and Individual Values (1951) influenced formulation of the theory of public choice and election theory. Building on Black's theory, Arrow concluded that in a non-dictatorial setting, there was no predictable outcome or preference order that can be discerned for a set of possible distributions.
Kepler Interactive Summary Kepler_Interactive Kepler Interactive is a video game publishing company founded in September 2021. Based in both London and Singapore, it is a co-owned by a group of independent game developers. It is most known for publishing games such as Tchia, Scorn, and Sifu.
K virtual machine Summary K_virtual_machine The K virtual machine (KVM) is a virtual machine developed by Sun Microsystems (now owned by Oracle Corporation), derived from the Java virtual machine (JVM) specification. The KVM was written from scratch in the programming language C. It is designed for small devices with 128K to 256K of available computer memory, and minimizes memory use. It supports a subset of the features of the higher end JVM. For example, a KVM may not support floating-point arithmetic and object finalization. The Connected Limited Device Configuration (CLDC) specifies use of the KVM. The 'K' in KVM stands for kilobyte, signifying that the KVM runs in kilobytes of memory in contrast to megabytes.
SAW filter Terminology Filter_(signal_processing) > Linear continuous-time filters > Terminology All-pass filter – all frequencies are passed, but the phase of the output is modified. Cutoff frequency is the frequency beyond which the filter will not pass signals. It is usually measured at a specific attenuation such as 3 dB.
Other metals Group 14 P-block_metal > Descriptive chemistry > Group 14 It has good corrosion resistance in air on account of forming a thin protective oxide layer. Pure tin has no structural uses. It is used in lead-free solders, and as a hardening agent in alloys of other metals, such as copper, lead, titanium and zinc.Lead is a soft metal (MH 1.5, but hardens close to melting) which, in many cases, is unable to support its own weight.
Symmetry in quantum mechanics Supersymmetry Symmetry_in_quantum_mechanics > Symmetries in quantum field theory and particle physics > Supersymmetry A Lie superalgebra is an algebra in which (suitable) basis elements either have a commutation relation or have an anticommutation relation. Symmetries have been proposed to the effect that all fermionic particles have bosonic analogues, and vice versa. These symmetry have theoretical appeal in that no extra assumptions (such as existence of strings) barring symmetries are made. In addition, by assuming supersymmetry, a number of puzzling issues can be resolved.
Burroughs large systems How programs map to the stack Burroughs_large_systems > Stack architecture > How programs map to the stack The visibility rules of ALGOL, a language designed for single pass compilers, mean that only variables declared before the current position are visible at that part of the code, thus the requirement for forward declarations. All variables declared in enclosing blocks are visible. Another case is that variables of the same name may be declared in inner blocks and these effectively hide the outer variables which become inaccessible.
Artificial Intelligence Classifiers and statistical learning methods Machine_intelligence > Tools > Classifiers and statistical learning methods All the observations combined with their class labels are known as a data set. When a new observation is received, that observation is classified based on previous experience.There are many kinds of classifiers in use. The decision tree is the simplest and most widely used symbolic machine learning algorithm. K-nearest neighbor algorithm was the most widely used analogical AI until the mid-1990s, and Kernel methods such as the support vector machine (SVM) displaced k-nearest neighbor in the 1990s. The naive Bayes classifier is reportedly the "most widely used learner" at Google, due in part to its scalability.Neural networks are also used as classifiers.
NAT traversal with session border controllers Summary NAT_traversal_with_session_border_controllers The callee is supposed to reply back with a SIP message destined to the IP addresses included in the received SIP message. This will obviously not work if the caller is behind a NAT and is using a private IP address. Probably the single biggest mistake in SIP design was ignoring the existence of NATs.
Thermochemical cycle Cycles based on the reversed Deacon process Thermochemical_cycle > Examples > Cycles with more than 3 steps and hybrid cycles > Cycles based on the reversed Deacon process Above 973K, the Deacon reaction is reversed, yielding hydrogen chloride and oxygen from water and chlorine: H2O + Cl2 → 2 HCl + 1/2 O2
Euclidean point Vector space dimension Point_(geometry) > Dimension of a point > Vector space dimension The dimension of a vector space is the maximum size of a linearly independent subset. In a vector space consisting of a single point (which must be the zero vector 0), there is no linearly independent subset. The zero vector is not itself linearly independent, because there is a non-trivial linear combination making it zero: 1 ⋅ 0 = 0 {\displaystyle 1\cdot \mathbf {0} =\mathbf {0} } .
Three-center two-electron bond Transition metal complexes Three-center_two-electron_bond > Transition metal complexes Three-center, two-electron bonding is pervasive in organotransition metal chemistry. A celebrated family of compounds featuring such interactions as called agostic complexes.
Privacy by default History and background Privacy_by_default > History and background The privacy by design framework was developed by Ann Cavoukian, Information and Privacy Commissioner of Ontario, following her joint work with the Dutch Data Protection Authority and the Netherlands Organisation for Applied Scientific Research in 1995. In 2009, the Information and Privacy Commissioner of Ontario co-hosted an event, Privacy by Design: The Definitive Workshop, with the Israeli Law, Information and Technology Authority at the 31st International Conference of Data Protection and Privacy Commissioner (2009).In 2010 the framework achieved international acceptance when the International Assembly of Privacy Commissioners and Data Protection Authorities unanimously passed a resolution on privacy by design recognising it as an international standard at their annual conference. Among other commitments, the commissioners resolved to promote privacy by design as widely as possible and foster the incorporation of the principle into policy and legislation.
Burn rate (chemistry) Measurement Burn_rate_(chemistry) > Measurement One device for measuring burning rate is a V-shaped metal channel about 1–2 feet long wherein a sample is placed, with a cross-sectional dimension of approximately 6 mm or 1/4 in. The sample is ignited on one end and time is measured until the flame front gets to the other end. Burn rate (typically expressed in mm/s, or in/s) is the sample length over time at a given pressure and temperature. For solid fuel propellant, the most common method of measuring burn rate is the Crawford Type Strand Burning Rate Bomb System (also known as the Crawford Burner or Strand Burner), as described in MIL-STD-286C.
Priority queuing Specialized heaps Priority_queuing > Implementation > Specialized heaps These queues are useful for sorting the vertices of a graph by their degree. : 374 A van Emde Boas tree supports the minimum, maximum, insert, delete, search, extract-min, extract-max, predecessor and successor] operations in O(log log C) time, but has a space cost for small queues of about O(2m/2), where m is the number of bits in the priority value. The space can be reduced significantly with hashing.
Project Orion (nuclear propulsion) Theoretical applications Project_Orion_(nuclear_propulsion) > Theoretical applications The dimensions and performance of Dyson's vehicles are given as: Later studies indicate that the top cruise velocity that can theoretically be achieved are a few percent of the speed of light (0.08–0.1c). An atomic (fission) Orion can achieve perhaps 9–11% of the speed of light. A nuclear pulse drive starship powered by fusion-antimatter catalyzed nuclear pulse propulsion units would be similarly in the 10% range and pure Matter-antimatter annihilation rockets would be theoretically capable of obtaining a velocity between 50% and 80% of the speed of light.
Growth hormones Excess Growth_hormones > Clinical significance > Excess Prolonged GH excess thickens the bones of the jaw, fingers and toes, resulting in heaviness of the jaw and increased size of digits, referred to as acromegaly. Accompanying problems can include sweating, pressure on nerves (e.g. carpal tunnel syndrome), muscle weakness, excess sex hormone-binding globulin (SHBG), insulin resistance or even a rare form of type 2 diabetes, and reduced sexual function. GH-secreting tumors are typically recognized in the fifth decade of life.
Laplace filter Example of the operator on a grid Discrete_Laplace_operator > Discrete heat equation > Example of the operator on a grid This section shows an example of a function ϕ {\textstyle \phi } diffusing over time through a graph. The graph in this example is constructed on a 2D discrete grid, with points on the grid connected to their eight neighbors. Three initial points are specified to have a positive value, while the rest of the values in the grid are zero. Over time, the exponential decay acts to distribute the values at these points evenly throughout the entire grid. The complete Matlab source code that was used to generate this animation is provided below. It shows the process of specifying initial conditions, projecting these initial conditions onto the eigenvalues of the Laplacian Matrix, and simulating the exponential decay of these projected initial conditions.
Pathogen transmission Horizontal transmission Pathogen_transmission > Beneficial microorganisms > Horizontal transmission Some beneficial symbionts are acquired horizontally, from the environment or unrelated individuals. This requires that host and symbiont have some method of recognizing each other or each other's products or services. Often, horizontally acquired symbionts are relevant to secondary rather than primary metabolism, for example for use in defense against pathogens, but some primary nutritional symbionts are also horizontally (environmentally) acquired. Additional examples of horizontally transmitted beneficial symbionts include bioluminescent bacteria associated with bobtail squid and nitrogen-fixing bacteria in plants.
E7 (mathematics) Cartan matrix E7_(mathematics) > Algebra > Cartan matrix . {\displaystyle {\begin{bmatrix}2&-1&0&0&0&0&0\\-1&2&-1&0&0&0&0\\0&-1&2&-1&0&0&0\\0&0&-1&2&-1&0&-1\\0&0&0&-1&2&-1&0\\0&0&0&0&-1&2&0\\0&0&0&-1&0&0&2\end{bmatrix}}.}
Conjunctive query Summary Conjunctive_query In database theory, a conjunctive query is a restricted form of first-order queries using the logical conjunction operator. Many first-order queries can be written as conjunctive queries. In particular, a large part of queries issued on relational databases can be expressed in this way. Conjunctive queries also have a number of desirable theoretical properties that larger classes of queries (e.g., the relational algebra queries) do not share.
Lattice confinement fusion Screened fusion Lattice_confinement_fusion > Technique > Screened fusion The energetic deuteron fuses with another deuteron, yielding either a 3helium nucleus and a neutron or a 3hydrogen nucleus and a proton. These fusion products may fuse with other deuterons, creating an alpha particle, or with another 3helium or 3hydrogen nucleus. Each releases energy, continuing the process.
Elliptical motion From initial position and velocity Radial_elliptic_orbit > Equation of motion > From initial position and velocity An orbit equation defines the path of an orbiting body m 2 {\displaystyle m_{2}\,\!} around central body m 1 {\displaystyle m_{1}\,\!} relative to m 1 {\displaystyle m_{1}\,\!}
Applications of artificial intelligence Sensors Applications_of_artificial_intelligence > Manufacturing > Sensors Artificial intelligence has been combined with digital spectrometry by IdeaCuria Inc., enable applications such as at-home water quality monitoring.
N-acetyltransferase 2 Summary N-acetyltransferase_2 N-acetyltransferase 2 (arylamine N-acetyltransferase), also known as NAT2, is an enzyme which in humans is encoded by the NAT2 gene.
Lipogenesis Hormonal regulation Triglyceride_synthesis > Hormonal regulation Insulin is a peptide hormone that is critical for managing the body's metabolism. Insulin is released by the pancreas when blood sugar levels rise, and it has many effects that broadly promote the absorption and storage of sugars, including lipogenesis. Insulin stimulates lipogenesis primarily by activating two enzymatic pathways. Pyruvate dehydrogenase (PDH), converts pyruvate into acetyl-CoA.
Pattern detection Number of important feature variables Pattern_Recognition > Overview > Number of important feature variables Feature selection algorithms attempt to directly prune out redundant or irrelevant features. A general introduction to feature selection which summarizes approaches and challenges, has been given. The complexity of feature-selection is, because of its non-monotonous character, an optimization problem where given a total of n {\displaystyle n} features the powerset consisting of all 2 n − 1 {\displaystyle 2^{n}-1} subsets of features need to be explored. The Branch-and-Bound algorithm does reduce this complexity but is intractable for medium to large values of the number of available features n {\displaystyle n} Techniques to transform the raw feature vectors (feature extraction) are sometimes used prior to application of the pattern-matching algorithm. Feature extraction algorithms attempt to reduce a large-dimensionality feature vector into a smaller-dimensionality vector that is easier to work with and encodes less redundancy, using mathematical techniques such as principal components analysis (PCA). The distinction between feature selection and feature extraction is that the resulting features after feature extraction has taken place are of a different sort than the original features and may not easily be interpretable, while the features left after feature selection are simply a subset of the original features.
Heterogeneous water oxidation Mechanism Heterogeneous_water_oxidation > Mechanism The shift in mechanism between the pH extremes has been attributed to the kinetic facility of oxidizing hydroxide ion relative to water. Using the Tafel equation, one can obtain kinetic information about the kinetics of the electrode material such as the exchange current density and the Tafel slope. OER is presumed to not take place on clean metal surfaces such as platinum, but instead an oxide surface is formed prior to oxygen evolution.
Pulmonary embolism Prognosis Pulmonary_embolus > Prognosis Blood flow is restored most rapidly in the first day or two after a PE. Improvement slows thereafter and some deficits may be permanent. There is controversy over whether small subsegmental PEs need treatment at all and some evidence exists that patients with subsegmental PEs may do well without treatment.Once anticoagulation is stopped, the risk of a fatal pulmonary embolism is 0.5% per year.Mortality from untreated PEs was said to be 26%.
Kubelka-Munk theory Treatment of inhomogeneous layers Kubelka–Munk_theory > Treatment of inhomogeneous layers A beam of light of unit intensity reaches the front surface, and by our assumptions, half is remitted and half is transmitted. The portion that is transmitted proceeds to the other surface undiminished. There it is again split where half (1/4 of the original incident intensity) is transmitted and half is remitted.
Cuckoo hashing Practice Cuckoo_hashing > Practice In practice, cuckoo hashing is about 20–30% slower than linear probing, which is the fastest of the common approaches. The reason is that cuckoo hashing often causes two cache misses per search, to check the two locations where a key might be stored, while linear probing usually causes only one cache miss per search. However, because of its worst case guarantees on search time, cuckoo hashing can still be valuable when real-time response rates are required. One advantage of cuckoo hashing is its link-list free property, which fits GPU processing well.
Flow-Based Programming Concepts Flow-Based_Programming > Concepts The following diagram shows the major entities of an FBP diagram (apart from the Information Packets). Such a diagram can be converted directly into a list of connections, which can then be executed by an appropriate engine (software or hardware). A, B and C are processes executing code components. O1, O2, and the two INs are ports connecting the connections M and N to their respective processes.
Logarithmic return Calculation Logarithmic_return > Calculation The return, or the holding period return, can be calculated over a single period. The single period may last any length of time. The overall period may, however, instead be divided into contiguous subperiods. This means that there is more than one time period, each sub-period beginning at the point in time where the previous one ended. In such a case, where there are multiple contiguous subperiods, the return or the holding period return over the overall period can be calculated by combining together the returns within each of the subperiods.
Hypovolemic shock Summary Hypovolemic_shock The "lethal triad" of ways trauma can lead to death is acidosis, hypothermia, and coagulopathy. It is possible for trauma to cause clotting problems even without resuscitation efforts.Damage control resuscitation is based on three principles: permissive hypotension: tries to balance temporary suboptimal perfusion to organs with conditions for halting blood loss by setting a goal of 90 mmHg systolic blood pressure hemostatic resuscitation: restoring blood volume in ways (with whole blood or equivalent) that interfere minimally with the natural process of stopping bleeding. damage control surgery.
Inception score Definition Inception_score > Definition Sample more images x i {\displaystyle x_{i}} from generator, and for each, compute D K L ( p d i s ( ⋅ \| x i ) ‖ p ^ ) {\displaystyle D_{KL}\left(p_{dis}(\cdot \|x_{i})\\|{\hat {p}}\right)} . Average the results, and take its exponential. RETURN the result.
Neuronal lineage marker Neural stem cells markers Neuronal_lineage_marker > Lineage markers > Neural stem cells markers Thus, as with other fields like haematopoiesis, a combination of positive and negative markers will be required to better define the central nervous system stem cell. Nonetheless, changes in the expression levels of specific molecules can be used to indicate the presence of neural stem cells in studies focused on further differentiation toward specific neural lineages. Usual markers used for neural stem cells include Nestin and SOX2.
Discrete time Continuous time Discrete_time > Continuous time In contrast, continuous time views variables as having a particular value only for an infinitesimally short amount of time. Between any two points in time there are an infinite number of other points in time. The variable "time" ranges over the entire real number line, or depending on the context, over some subset of it such as the non-negative reals. Thus time is viewed as a continuous variable.
Maxwell’s equations Faraday's law Maxwells_equations > Conceptual descriptions > Faraday's law The Maxwell–Faraday version of Faraday's law of induction describes how a time-varying magnetic field corresponds to curl of an electric field. In integral form, it states that the work per unit charge required to move a charge around a closed loop equals the rate of change of the magnetic flux through the enclosed surface. The electromagnetic induction is the operating principle behind many electric generators: for example, a rotating bar magnet creates a changing magnetic field and generates an electric field in a nearby wire.
Bilderberg group Organizational structure Bilderberg_group > Organizational structure Meetings are organized by a steering committee with two members from each of approximately 18 nations. Official posts include a chairman and an Honorary Secretary General. The group's rules do not contain a membership category but former participants receive the annual conference reports. The only category that exists is "member of the steering committee".
Toluene Side chain reactions Toluene > Chemical properties > Side chain reactions Typical catalysts include cobalt or manganese naphthenates. Related but laboratory-scale oxidations involve the use of potassium permanganate to yield benzoic acid and chromyl chloride to yield benzaldehyde (Étard reaction). The methyl group in toluene undergoes deprotonation only with very strong bases; its pKa is estimated to be approximately 41.
Genomic Medicine Institute Leadership Genomic_Medicine_Institute > Leadership Charis Eng is the Chair and founding Director of the Genomic Medicine Institute. She holds the Sondra J. and Stephen R. Hardis Endowed Chair of Cancer Genomic Medicine at the Cleveland Clinic and is an American Cancer Society Clinical Research Professor. She is also Professor and Vice Chair of the Department of Genetics at Case Western Reserve University School of Medicine, and a member of the U.S. Department of Health and Human Services Secretary's Advisory Committee on Genetics, Health and Society (SACGHS). She was elected as a member of the National Academy of Science's Institute of Medicine (IOM) in 2010.
Condorcet methods Single-method systems Condorcet_method > Single-method systems Dodgson's method extends the Condorcet method by swapping candidates until a Condorcet winner is found. The winner is the candidate which requires the minimum number of swaps. Ranked pairs breaks each cycle in the pairwise preference graph by dropping the weakest majority in the cycle, thereby yielding a complete ranking of the candidates.
Galileo's finger Physics Galileo_Galilei > Scientific contributions > Physics Galileo's theoretical and experimental work on the motions of bodies, along with the largely independent work of Kepler and René Descartes, was a precursor of the classical mechanics developed by Sir Isaac Newton.
Mesocorticolimbic projection Cortico-basal ganglia-thalamo-cortical loop Mesocorticolimbic_projection > Function > Cortico-basal ganglia-thalamo-cortical loop However, the second model proposes that the actions do not originate in the basal ganglia, and instead originate in the cortex and are selected by the basal ganglia. This model proposes that the direct pathway controls appropriate behavior and the indirect suppresses actions not suitable for the situation. This model proposes that tonic dopaminergic firing increases the activity of the direct pathway, causing a bias towards executing actions faster.These models of the basal ganglia are thought to be relevant to the study of OCD, ADHD, Tourette syndrome, Parkinson's disease, schizophrenia, and addiction. For example, Parkinson's disease is hypothesized to be a result of excessive inhibitory pathway activity, which explains the slow movement and cognitive deficits, while Tourettes is proposed to be a result of excessive excitatory activity resulting in the tics characteristic of Tourettes.
Glossary of gene expression terms G Glossary_of_genetics_(0–L) > G In any given organism, a single reproductive cycle, or the phase between two consecutive reproductive events, i.e. between an individual organism's reproduction and that of the progeny of that reproduction; or the actual or average length of time required to complete a single reproductive cycle, either for a particular lineage or for a population or species as a whole. 2.
Intelligent Speed Adaptation (ISA) Optical recognition systems Intelligent_Speed_Adaptation_(ISA) > Speed and location determination and verification > Optical recognition systems Optical recognition technology has focused on recognizing speed signs, road markings and roadside objects such as "cat's eyes". This system requires the vehicle to pass a speed sign or similar indicator and for data about the sign or indicator to be registered by a scanner or a camera system. As the system recognizes a sign, the speed limit data is obtained and compared to the vehicle's speed. The system uses that speed limit until it detects a speed sign with a different limit. It is also possible to use computer vision to determine the assured clear distance ahead.
Public Suffix List List Public_Suffix_List > List Security issues like a same-site attack can arise if the Public Suffix List is incorrect, or if browsers or sites are not properly configured.Some uses for the list are: Avoiding "supercookies", HTTP cookies set by related-domain attackers for high-level domain name suffixes. In other words, a page at foo.example.co.uk might normally have access to cookies at bar.example2.co.uk, but example.co.uk should be walled off from cookies at example2.co.uk, to prevent a same-site attack, since the latter two domains could be registered by different owners.
Bunker experiment Background Bunker_experiment > Background Aschoff was the first test subject, with Rütger Wever observing. The experiment began in 1966 and continued until the early 1980s. As of 2013, the bunker was still in existence, although quite dilapidated.
Glide wax Glide wax Ski_wax > Glide wax Glide wax can be applied to alpine skis, snowboards, skate skis, classic skis, back-country skis, and touring skis. Traditional waxes comprise solid hydrocarbons. High-performance "fluorocarbon" waxes also contain fluorine, which substitutes some fraction of the hydrogen atoms in the hydrocarbons with fluorine atoms to achieve lower coefficients of friction and higher water repellency than the pure hydrocarbon wax can achieve. Wax is adjusted for hardness to minimize sliding friction as a function of snow properties, which include the effects of: Age: Reflects the metamorphism of snow crystals that are sharp and well-defined, when new, but with aging become broken or truncated with wind action or rounded into ice granules with freeze-thaw, all of which affects a ski's coefficient of friction. Moisture content: The percentage of mass that is liquid water and may create suction friction with the base of the ski as it slides. Temperature: Affects the ease with which sliding friction can melt snow crystals at the interface between ski and snow.
Symmetries in quantum mechanics Continuous symmetries Symmetry_in_quantum_mechanics > Symmetry transformations on the wavefunction in non-relativistic quantum mechanics > Continuous symmetries Generally, the correspondence between continuous symmetries and conservation laws is given by Noether's theorem. The form of the fundamental quantum operators, for example energy as a partial time derivative and momentum as a spatial gradient, becomes clear when one considers the initial state, then changes one parameter of it slightly. This can be done for displacements (lengths), durations (time), and angles (rotations). Additionally, the invariance of certain quantities can be seen by making such changes in lengths and angles, illustrating conservation of these quantities.
Dynamical billiards Magnetic billiards Dynamical_billiards > Notable billiards and billiard classes > Magnetic billiards Magnetic billiards represent billiards where a charged particle is propagating under the presence of a perpendicular magnetic field. As a result, the particle trajectory changes from a straight line into an arc of a circle. The radius of this circle is inversely proportional to the magnetic field strength. Such billiards have been useful in real world applications of billiards, typically modelling nanodevices (see Applications).
Prime-counting function Summary Prime-counting_function In mathematics, the prime-counting function is the function counting the number of prime numbers less than or equal to some real number x. It is denoted by π(x) (unrelated to the number π).
Wallpaper pattern Symmetry groups Wallpaper_groups > Symmetry groups These depend, apart from the wallpaper group, on a number of parameters for the translation vectors, the orientation and position of the reflection axes and rotation centers. The numbers of degrees of freedom are: 6 for p2 5 for pmm, pmg, pgg, and cmm 4 for the rest.However, within each wallpaper group, all symmetry groups are algebraically isomorphic. Some symmetry group isomorphisms: p1: Z2 pm: Z × D∞ pmm: D∞ × D∞.
Kernel streaming Kernel Streaming Audio_Compression_Manager > Kernel Streaming Kernel Streaming or Direct Kernel streaming (Direct KS) is a technique that supports kernel-mode processing of streamed data. It enables efficient real-time streaming for multimedia devices such as sound cards and TV tuner cards. Kernel streaming allows a device driver to create DirectShow-like filters and pins in kernel mode, providing access to hardware, lower latency communication and still be used within a DirectShow filter graph. Kernel streaming was introduced in Windows 98.

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