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we present a compilation of lego technic parts to provide easy - to - build constructions of basic planar linkages. some technical issues and their possible solutions are discussed. to solve questions on fine details - - - like deciding whether the motion is an exactly straight line or not - - - we refer to the dynamic mathematics software tool geogebra.
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arxiv:1712.00440
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live migration of services is a prerequisite for various use cases that must be fulfilled for the realization of industry 4. 0. in addition, many different types of services need to provide mobility and consequently need to be migrated live. these can be offloaded algorithms from mobile devices, such as unmanned vehicles or robots, security services, communication services or classic control tasks. in particular, the latter place very high demands on determinism and latency. here, it is of utmost importance that the downtime of the service is as low as possible. since existing live migration approaches try to optimize multiple metrics such as downtime, migration time as well as energy consumption, which are equally relevant in the it domain, it is not possible to use any of these approaches without adoptions. therefore, a novel concept is proposed that builds on top of both existing migration approaches as well as virtualization technologies and aims primarily at minimizing service downtime. furthermore, the concept is evaluated using a test environment. the results show that a sub - millisecond downtime can be achieved with the proposed concept. moreover, the total migration time is in the range of several hundred milliseconds for the highest performance setting and two seconds for a non - invasive approach.
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arxiv:2203.12935
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uv and optical surveys are essential to gain insight into the processes driving galaxy formation and evolution. the rest - frame uv emission is key to measure the cosmic sfr. however, uv light is strongly reddened by dust. in starburst galaxies, the uv colour and the attenuation are linked, allowing to correct for dust extinction. unfortunately, evidence has been accumulating that the relation between uv colour and attenuation is different for normal star - forming galaxies when compared to starburst galaxies. it is still not understood why star - forming galaxies deviate from the uv colour - attenuation relation of starburst galaxies. previous work and models hint that the role of the shape of the attenuation curve and the age of stellar populations have an important role. in this paper we aim at understanding the fundamental reasons to explain this deviation. we have used the cigale sed fitting code to model the far uv to the far ir emission of a set of 7 reasonably face - on spiral galaxies from the hrs. we have explored the influence of a wide range of physical parameters to quantify their influence and impact on the accurate determination of the attenuation from the uv colour, and why normal galaxies do not follow the same relation as starburst galaxies. we have found that the deviation can be best explained by intrinsic uv colour differences between different regions in galaxies. variations in the shape of the attenuation curve can also play a secondary role. standard age estimators of the stellar populations prove to be poor predictors of the intrinsic uv colour. these results are also retrieved on a sample of 58 galaxies when considering their integrated fluxes. when correcting the emission of normal star - forming galaxies for the attenuation, it is crucial to take into account possible variations in the intrinsic uv colour as well as variations of the shape of the attenuation curve.
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arxiv:1201.2405
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we investigate the invariant metrics and complex geodesics in the universal teichm \ " { u } ller space and teichm \ " { u } ller space of the punctured disk using milin ' s coefficient inequalities. this technique allows us to establish that all non - expanding invariant metrics in either of these spaces coincide with its intrinsic teichm \ " { u } ller metric. other applications concern the variational theory for univalent functions with quasiconformal extension. it turns out that geometric features caused by the equality of metrics and connection with complex geodesics provide deep distortion results for various classes of such functions and create new phenomena which do not appear in the classical geometric function theory.
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arxiv:1405.4830
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this paper gives an overview of the model of a neutron star with non - zero strangeness constructed within the framework of the nonlinear realization of the chiral $ su ( 3 ) _ { l } \ times su ( 3 ) _ { r } $ symmetry. the emphasis is put on the physical properties of the matter of a neutron star. the obtained solution is particularly aimed at the problem of the construction of a theoretical model of a neutron star matter with hyperons that will give high value of the maximum mass.
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arxiv:1312.3219
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in recent years, the development of diffusion models has led to significant progress in image and video generation tasks, with pre - trained models like the stable diffusion series playing a crucial role. inspired by model pruning which lightens large pre - trained models by removing unimportant parameters, we propose a novel model fine - tuning method to make full use of these ineffective parameters and enable the pre - trained model with new task - specified capabilities. in this work, we first investigate the importance of parameters in pre - trained diffusion models, and discover that the smallest 10 % to 20 % of parameters by absolute values do not contribute to the generation process. based on this observation, we propose a method termed sara that re - utilizes these temporarily ineffective parameters, equating to optimizing a sparse weight matrix to learn the task - specific knowledge. to mitigate overfitting, we propose a nuclear - norm - based low - rank sparse training scheme for efficient fine - tuning. furthermore, we design a new progressive parameter adjustment strategy to make full use of the re - trained / finetuned parameters. finally, we propose a novel unstructural backpropagation strategy, which significantly reduces memory costs during fine - tuning. our method enhances the generative capabilities of pre - trained models in downstream applications and outperforms traditional fine - tuning methods like lora in maintaining model ' s generalization ability. we validate our approach through fine - tuning experiments on sd models, demonstrating significant improvements. sara also offers a practical advantage that requires only a single line of code modification for efficient implementation and is seamlessly compatible with existing methods.
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arxiv:2409.06633
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we study theoretically the josephson effect in d - wave superconductor / diffusive normal metal / insulator / diffusive normal metal / d - wave superconductor ( d / dn / i / dn / d ) junctions. this model is aimed to describe practical junctions in high - $ t _ c $ cuprate superconductors, in which the product of the critical josephson current ( $ i _ c $ ) and the normal state resistance ( $ r $ ) ( the so - called $ i _ { \ rm c } r $ product ) is very small compared to the prediction of the standard theory. we show that the $ i _ { \ rm c } r $ product in d / dn / i / dn / d junctions can be much smaller than that in d - wave superconductor / insulator / d - wave superconductor junctions and formulate the conditions necessary to achieve large $ i _ { \ rm c } r $ product in d / dn / i / dn / d junctions. the proposed theory describes the behavior of $ i _ { \ rm c } r $ products quantitatively in high - $ t _ { \ rm c } $ cuprate junctions.
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arxiv:0704.3126
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we study equilibrium crystal shapes of a topological insulator ( ti ), a topological crystalline insulator ( tci ) protected by mirror symmetry, and a second - order topological insulator ( soti ) protected by inversion symmetry. by adding magnetic fields to the three - dimensional ti, we can realize the mirror - symmetry - protected tci and the inversion - symmetry - protected soti. they each have topological boundary states in different positions : the tci has gapless states on the surfaces that are invariant under the symmetry operation, and the soti has gapless states at the intersections between certain surfaces. in this paper, we discuss how these boundary states affect the surface energies and the equilibrium crystal shapes in terms of the calculations of the simple tight - binding model by using the wulff construction. by comparing the changes in the shapes of the ti to that of the trivial insulator through the process of applying the magnetic fields, we show that the presence / absence of the topological boundary states affects the emergence of the specific facets in a different way from the trivial insulator.
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arxiv:2304.08150
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##egrators institution of mechanical engineers - mechatronics, informatics and control group ( micg ) systems science & control engineering : an open access journal
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https://en.wikipedia.org/wiki/Control_engineering
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the disjointness of a stabilizer code is a quantity used to constrain the level of the logical clifford hierarchy attainable by transversal gates and constant - depth quantum circuits. we show that for any positive integer constant $ c $, the problem of calculating the $ c $ - disjointness, or even approximating it to within a constant multiplicative factor, is np - complete. we provide bounds on the disjointness for various code families, including the css codes, concatenated codes and hypergraph product codes. we also describe numerical methods of finding the disjointness, which can be readily used to rule out the existence of any transversal gate implementing some non - clifford logical operation in small stabilizer codes. our results indicate that finding fault - tolerant logical gates for generic quantum error - correcting codes is a computationally challenging task.
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arxiv:2108.04738
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present experimental datas have shown a 3. 8 $ \ sigma $ level discrepancy with the standard model in $ \ overline { b } \ to d ^ { ( * ) } \ tau \ bar { \ nu } _ { \ tau } $. some new physics models have been considered to explain this discrepancy possibly with new source of the cp violation. in this paper, we construct cp violating observables by using multi - pion decays in $ b \ to d \ tau \ nu _ { \ tau } $, and estimate sensitivity of these observables to generic cp violating operators. we also discuss possibilities of cp violation in leptoquark models and in 2hdm of type - iii.
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arxiv:1403.5892
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in mathematics, a character is ( most commonly ) a special kind of function from a group to a field ( such as the complex numbers ). there are at least two distinct, but overlapping meanings. other uses of the word " character " are almost always qualified. = = multiplicative character = = a multiplicative character ( or linear character, or simply character ) on a group g is a group homomorphism from g to the multiplicative group of a field ( artin 1966 ), usually the field of complex numbers. if g is any group, then the set ch ( g ) of these morphisms forms an abelian group under pointwise multiplication. this group is referred to as the character group of g. sometimes only unitary characters are considered ( thus the image is in the unit circle ) ; other such homomorphisms are then called quasi - characters. dirichlet characters can be seen as a special case of this definition. multiplicative characters are linearly independent, i. e. if Ο 1, Ο 2, β¦, Ο n { \ displaystyle \ chi _ { 1 }, \ chi _ { 2 }, \ ldots, \ chi _ { n } } are different characters on a group g then from a 1 Ο 1 + a 2 Ο 2 + + a n Ο n = 0 { \ displaystyle a _ { 1 } \ chi _ { 1 } + a _ { 2 } \ chi _ { 2 } + \ dots + a _ { n } \ chi _ { n } = 0 } it follows that a 1 = a 2 = = a n = 0 { \ displaystyle a _ { 1 } = a _ { 2 } = \ cdots = a _ { n } = 0 }. = = character of a representation = = the character Ο : g β f { \ displaystyle \ chi : g \ to f } of a representation : g β g l ( v ) { \ displaystyle \ phi \ colon g \ to \ mathrm { gl } ( v ) } of a group g on a finite - dimensional vector space v over a field f is the trace of the representation { \ displaystyle \ phi } ( serre 1977 ), i. e. Ο ( g ) = tr ( ( g ) ) { \ displaystyle \ chi _ { \ phi } ( g ) = \ operatorname { tr } ( \ phi ( g ) ) } for g β g { \ displaystyle
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https://en.wikipedia.org/wiki/Character_(mathematics)
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in recent years, a considerable amount of work has been devoted to generalizing linear discriminant analysis to overcome its incompetence for high - dimensional classification ( witten & tibshirani 2011, cai & liu 2011, mai et al. 2012, fan et al. 2012 ). in this paper, we develop high - dimensional semiparametric sparse discriminant analysis ( hd - sesda ) that generalizes the normal - theory discriminant analysis in two ways : it relaxes the gaussian assumptions and can handle non - polynomial ( np ) dimension classification problems. if the underlying bayes rule is sparse, hd - sesda can estimate the bayes rule and select the true features simultaneously with overwhelming probability, as long as the logarithm of dimension grows slower than the cube root of sample size. simulated and real examples are used to demonstrate the finite sample performance of hd - sesda. at the core of the theory is a new exponential concentration bound for semiparametric gaussian copulas, which is of independent interest.
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arxiv:1304.4983
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in our recent paper ( hep - ph / 9501348 ) we argued that the bjorken variable $ x $ in deep inelastic scattering cannot be interpreted as the light cone momentum fraction $ \ xi $ even in the bjorken limit and in zero order of the perturbation theory. the purpose of the present paper is to qualitatively explain this fact using only a few simplest kinematical relations.
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arxiv:hep-ph/9502236
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numerical simulations predict a considerable fraction of the missing baryons at redshift z ~ 0 resting in the so called warm - hot intergalactic medium ( whim ). the filaments and sheets of the whim have high temperatures 10 ^ 5 - 10 ^ 7 k ) and a high degree of ionization while having only low to intermediate densities. the particular physical conditions of the whim structures, e. g. density and temperature profiles, velocity fields, are expected to leave their special imprint on spectroscopic observations. in order to get further insight into these conditions, we perform hydrodynamical simulations of the whim. instead of analyzing large simulations of cosmological structure formation, we simulate particular well - defined structures and study the impact of different physical processes as well as of the scale dependencies. we start with the comprehensive study of the one - dimensional collapse ( pancake ) and examine the influence of radiative cooling, heating due to an uv background, and thermal conduction. we investigate the effect of small scale perturbations given according to the initial cosmological power spectrum. if the initial perturbation length scale l exceeds ~ 2 mpc the collapse leads to shock confined structures. as a result of radiative cooling and of heating due to an uv background a relatively cold and dense core forms in the one - dimensional case. the properties of the core ( extension, density, and temperature ) are correlated with l. for larger l the core sizes are more concentrated. thermal conduction enhances this trend and may even result in an evaporation of the core. our estimates predict that a core may start to evaporate for perturbation lengths larger than l ~ 30 mpc. the obtained detailed profiles for density and temperature for prototype whim structures allow for the determination of possible spectral signatures by the whim.
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arxiv:1008.2311
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sim - to - real transfer trains rl agents in the simulated environments and then deploys them in the real world. sim - to - real transfer has been widely used in practice because it is often cheaper, safer and much faster to collect samples in simulation than in the real world. despite the empirical success of the sim - to - real transfer, its theoretical foundation is much less understood. in this paper, we study the sim - to - real transfer in continuous domain with partial observations, where the simulated environments and real - world environments are modeled by linear quadratic gaussian ( lqg ) systems. we show that a popular robust adversarial training algorithm is capable of learning a policy from the simulated environment that is competitive to the optimal policy in the real - world environment. to achieve our results, we design a new algorithm for infinite - horizon average - cost lqgs and establish a regret bound that depends on the intrinsic complexity of the model class. our algorithm crucially relies on a novel history clipping scheme, which might be of independent interest.
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arxiv:2210.15598
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in this paper, we present static and spherically symmetric vacuum solutions to the mass - dimension $ d \ leq 4 $ action of an effective - field theory, choosing the diffeomorphism symmetry to be broken explicitly. by using the reduced - action method with a schwarzschild seed - solution, we find static and spherically symmetric black hole solutions to the field equations to linear order in the symmetry - breaking coefficients, which are consistent solutions to the modified einstein equations at the same order. using several ans \ " atze for the symmetry - breaking coefficient we classify the allowed solutions, and we compute standard consequences and observables, including horizons, thermodynamics, photon geodesics, and perihelion precession. we find that the horizon structure of some of our solutions are similar to the reissner - nordstr \ " om case, and that several of them exhibit physical singularities at $ r = 2m $. we note in particular that introducing more than one non - zero coefficient for spacetime - symmetry breaking coefficient leads to a solution with three horizons ; the aim is to obtain observables that can be confronted to black holes observational data.
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arxiv:2411.18255
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humans can naturally learn to execute a new task by seeing it performed by other individuals once, and then reproduce it in a variety of configurations. endowing robots with this ability of imitating humans from third person is a very immediate and natural way of teaching new tasks. only recently, through meta - learning, there have been successful attempts to one - shot imitation learning from humans ; however, these approaches require a lot of human resources to collect the data in the real world to train the robot. but is there a way to remove the need for real world human demonstrations during training? we show that with task - embedded control networks, we can infer control polices by embedding human demonstrations that can condition a control policy and achieve one - shot imitation learning. importantly, we do not use a real human arm to supply demonstrations during training, but instead leverage domain randomisation in an application that has not been seen before : sim - to - real transfer on humans. upon evaluating our approach on pushing and placing tasks in both simulation and in the real world, we show that in comparison to a system that was trained on real - world data we are able to achieve similar results by utilising only simulation data.
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arxiv:1911.01103
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in this letter we describe an approach to the current algebra based in the path integral formalism. we use this method for abelian and non - abelian quantum field theories in 1 + 1 and 2 + 1 dimensions and the correct expressions are obtained. our results show the independence of the regularization of the current algebras.
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arxiv:hep-th/9806067
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recently, band - off - diagonal superconductivity has been proposed [ nat. commun. 14, 7134 ( 2023 ) ] as a candidate pairing state for twisted graphene systems. based on mean - field theory, it was shown that it not only naturally emerges from both intervalley electron - phonon coupling and fluctuations of the nearby correlated insulator, but also exhibits nodal and gapped regimes as indicated by scanning tunneling microscopy experiments. here we study band - off - diagonal pairing within eliashberg theory. we show that despite the additional frequency dependence, the leading - order description of both intervalley coherent fluctuations or intervalley phonons exhibits a symmetry prohibiting admixture of an intraband component to the interband pairing state. it is found that even - and odd - frequency pairing mix, which originates from the reduced number of flavor degrees of freedom in the normal state. from analytic continuation, we obtain the electronic spectral function showing that, also within eliashberg theory, the interband nature leads to an enhanced spectral weight below the order - parameter energy compared to band - diagonal pairing. finally, we also study the superfluid stiffness of band - off - diagonal pairing, taking into account multi - band and quantum geometry effects. it is shown that for $ s $ - wave and chiral momentum dependencies, conventionally leading to fully gapped phases, an interband structure reduces the temperature scale below which the stiffness saturates. depending on parameters, for the chiral state, this scale can even be suppressed all the way to zero temperature leading to a complex competition of multiple dispersive and geometrical contributions. our results show that interband pairing might also be able to explain more recent stiffness measurements in the superconducting state of twisted multilayer graphene.
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arxiv:2501.12435
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college and university students of government and politics in the united states is pi sigma alpha, while pi alpha alpha is a national honor society specifically designated for public administration. = = see also = = artificial intelligence and elections β use and impact of ai on political elections comparative politics β field in political science history of political science international relations β study of relationships between two or more states political history of the world political identity β type of social identity political philosophy β study of the foundations of politics = = = lists = = = index of politics articles political lists outline of political science β overview of and topical guide to political science = = references = = = = further reading = = = = external links = = ipsaportal : top 300 websites for political science archived 27 february 2015 at the wayback machine observatory of international research ( ooir ) : latest papers and trends in political science prol : political science research online ( prepublished research ) = = = professional organizations = = = european consortium for political research institute for comparative research in human and social sciences ( icr ) in japan international association for political science students international political science association international studies association midwest political science association political studies association of the uk southern political science association = = = library guides = = = library. " political science ". research guides. michigan : university of michigan. archived from the original on 7 july 2014. retrieved 15 february 2014. bodleian libraries. " political science ". libguides. uk : university of oxford. archived from the original on 18 february 2014. retrieved 15 february 2014. library. " politics research guide ". libguides. new jersey : princeton university. archived from the original on 23 july 2014. retrieved 15 february 2014. libraries. " political science ". research guides. new york : syracuse university. archived from the original on 8 july 2014. retrieved 15 february 2014. university libraries. " political science ". research guides. texas : texas a & m university. archived from the original on 21 october 2014. retrieved 15 february 2014.
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https://en.wikipedia.org/wiki/Political_science
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we compute robust lower limits on the spin temperature, $ t _ { \ rm s } $, of the $ z = 8. 4 $ intergalactic medium ( igm ), implied by the upper limits on the 21 - cm power spectrum recently measured by paper - 64. unlike previous studies which used a single epoch of reionization ( eor ) model, our approach samples a large parameter space of eor models : the dominant uncertainty when estimating constraints on $ t _ { \ rm s } $. allowing $ t _ { \ rm s } $ to be a free parameter and marginalizing over eor parameters in our markov chain monte carlo code 21cmmc, we infer $ t _ { \ rm s } \ ge3 { \ rm k } $ ( corresponding approximately to $ 1 \ sigma $ ) for a mean igm neutral fraction of $ \ bar { x } _ { \ rm h { \ scriptsize i } } \ gtrsim0. 1 $. we further improve on these limits by folding - in additional eor constraints based on : ( i ) the dark fraction in qso spectra, which implies a strict upper limit of $ \ bar { x } _ { \ rm h { \ scriptsize i } } [ z = 5. 9 ] \ leq 0. 06 + 0. 05 \, ( 1 \ sigma ) $ ; and ( ii ) the electron scattering optical depth, $ \ tau _ { \ rm e } = 0. 066 \ pm0. 016 \, ( 1 \ sigma ) $ measured by the planck satellite. by restricting the allowed eor models, these additional observations tighten the approximate $ 1 \ sigma $ lower limits on the spin temperature to $ t _ { \ rm s } \ ge 6 $ k. thus, even such preliminary 21 - cm observations begin to rule out extreme scenarios such as ` cold reionization ', implying at least some prior heating of the igm. the analysis framework developed here can be applied to upcoming 21 - cm observations, thereby providing unique insights into the sources which heated and subsequently reionized the very early universe.
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arxiv:1509.02158
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large language models ( llms ) are known to exhibit demographic biases, yet few studies systematically evaluate these biases across multiple datasets or account for confounding factors. in this work, we examine llm alignment with human annotations in five offensive language datasets, comprising approximately 220k annotations. our findings reveal that while demographic traits, particularly race, influence alignment, these effects are inconsistent across datasets and often entangled with other factors. confounders - - such as document difficulty, annotator sensitivity, and within - group agreement - - account for more variation in alignment patterns than demographic traits alone. specifically, alignment increases with higher annotator sensitivity and group agreement, while greater document difficulty corresponds to reduced alignment. our results underscore the importance of multi - dataset analyses and confounder - aware methodologies in developing robust measures of demographic bias in llms.
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arxiv:2411.08977
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an integral formulation for acoustic radiation in moving flows is presented. it is based on a potential formulation for acoustic radiation on weakly non - uniform subsonic mean flows. this work is motivated by the absence of suitable kernels for wave propagation on non - uniform flow. the integral solution is formulated using a green ' s function obtained by combining the taylor and lorentz transformations. although most conventional approaches based on either transform solve the helmholtz problem in a transformed domain, the current green ' s function and associated integral equation are derived in the physical space. a dimensional error analysis is developed to identify the limitations of the current formulation. numerical applications are performed to assess the accuracy of the integral solution. it is tested as a means of extrapolating a numerical solution available on the outer boundary of a domain to the far field, and as a means of solving scattering problems by rigid surfaces in non - uniform flows. the results show that the error associated with the physical model deteriorates with increasing frequency and mean flow mach number. however, the error is generated only in the domain where mean flow non - uniformities are significant and is constant in regions where the flow is uniform.
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arxiv:1509.06426
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the phase retrieval problem in the classical setting is to reconstruct real / complex functions from the magnitudes of their fourier / frame measurements. in this paper, we consider a new phase retrieval paradigm in the complex / quaternion / vector - valued setting, and we provide several characterizations to determine complex / quaternion / vector - valued functions $ f $ in a linear space $ s $ of ( in ) finite dimensions, up to a trivial ambiguity, from the magnitudes $ \ | \ phi ( f ) \ | $ of their linear measurements $ \ phi ( f ), \ phi \ in \ phi $. our characterization in the scalar setting implies the well - known equivalence between the complement property for linear measurements $ \ phi $ and the phase retrieval of linear space $ s $. in this paper, we also discuss the affine phase retrieval of vector - valued functions in a linear space and the reconstruction of vector fields on a graph, up to an orthogonal matrix, from their absolute magnitudes at vertices and relative magnitudes between neighboring vertices.
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arxiv:1909.02078
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entanglement ( en ) is a determinative correlation in designation of quantum gates and quantum memories. all quantum operations which are assembled by quantum circuits, are exposed to environment. however, quantum discord ( qd ) as a new key of resource for quantum information theory is in spotlight of research. therefore, the study of en and qd in open quantum systems seems to be important. in this brief report, we derived a formula for specific heat of the principle system as a part of open quantum system ( in special for jaynes - cumming regime ), and we looked for relations between entanglement and specific heat which is important for designing of the quantum memory. we also studied the dynamics of thermal en and qd in jaynes - cumming regime including the non - markovian processes via born - markove approximation and obtained a regions of temperature and coupling constant between parts of systems which the entanglement of formation had a stable behavior. it seems to be useful to design the quantum gates. we observed the negative and divergence specific heat ( in contradiction with third law of thermodynamics ) in low temperature because the state of open system is entangle. according to obtained results, we did not find out any violence oscillation in quantum discord and because entanglement decreases with respect time, fast response to inputs is crucial for assembling quantum circuits and quantum memory.
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arxiv:1704.02811
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face recognition ( fr ) using deep convolutional neural networks ( dcnns ) has seen remarkable success in recent years. one key ingredient of dcnn - based fr is the appropriate design of a loss function that ensures discrimination between various identities. the state - of - the - art ( sota ) solutions utilise normalised softmax loss with additive and / or multiplicative margins. despite being popular, these softmax + margin based losses are not theoretically motivated and the effectiveness of a margin is justified only intuitively. in this work, we utilise an alternative framework that offers a more direct mechanism of achieving discrimination among the features of various identities. we propose a novel loss that is equivalent to a triplet loss with proxies and an implicit mechanism of hard - negative mining. we give theoretical justification that minimising the proposed loss ensures a minimum separability between all identities. the proposed loss is simple to implement and does not require heavy hyper - parameter tuning as in the sota solutions. we give empirical evidence that despite its simplicity, the proposed loss consistently achieves sota performance in various benchmarks for both high - resolution and low - resolution fr tasks.
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arxiv:2103.03503
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using a hybrid of machine learning and epidemiological approaches, we propose a novel data - driven approach in predicting us covid - 19 deaths at a county level. the model gives a more complete description of the daily death distribution, outputting quantile - estimates instead of mean deaths, where the model ' s objective is to minimize the pinball loss on deaths reported by the new york times coronavirus county dataset. the resulting quantile estimates accurately forecast deaths at an individual - county level for a variable - length forecast period, and the approach generalizes well across different forecast period lengths. we won the caltech - run modeling competition out of 50 + teams, and our aggregate is competitive with the best covid - 19 modeling systems ( on root mean squared error ).
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arxiv:2010.04052
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a set of all symmetric banach function spaces defined on [ 0, 1 ] is equipped with the partial order by the relation of continuous inclusion. properties of symmetric spaces, which do not depend of their position in the ordered structure, are studied. with the help of the j. peetre ' s interpolation scheme it is shown that for any pair of symmetric spaces e, f such that f is absolutely continuously included in e there exists an intermediate ( so called, peetre ' s ) space k ( e, f ; w ), where w is a space with an unconditional basis, that is reflexive or, respectively, weakly sequentially complete provided w also is reflexive or, respectively, weakly sequentially complete.
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arxiv:math/0206183
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numerical simulation studies in 2d with the addition of noise are reported for the convection of a supercritical fluid, 3he, in a rayleigh - be ' nard cell where the fluid parameters and cell height l are the same as in published laboratory experiments. the noise addition is to accelerate the instability onset after starting the heat flow across the fluid, so as to bring simulations into better agreement with experimental observations. homogeneous temperature noise and spatial lateral periodic temperature variations in the top plate were programmed into the simulations. a speed - up in the instability onset was obtained, which was most effective through the spatial temperature variations with a period of 2l, close to the wavelength of a pair of convections rolls. for a small amplitude of 0. 5 microk, this perturbation gave a semiquantitative agreement with experimental observations. results for various noise amplitudes are presented and discussed in relation to predictions by el khouri and carle ` s.
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arxiv:physics/0411187
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we construct numerical vortex solutions in a ( 3 + 1 ) dimensional minkowski space - time for the extended version of the skyrme - faddeev model with target space $ cp ^ n $. the solutions are essentially composed of $ n $ - th single vortex which does not belong to the integrable sector. they have finite energy per unit length and contain waves propagating along vortices with the speed of light. in this letter we report on the case n = 2 and show existence of the solutions with the charges $ ( n _ 1, n _ 2 ) = ( 1, 2 ) $.
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arxiv:1210.7523
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time - periodic systems allow engineering new effective hamiltonians from limited physical interactions. for example, the inverted position of the kapitza pendulum emerges as a stable equilibrium with rapid drive of its pivot point. in this work, we propose the $ \ textit { kapitzonium } $ : a floquet qubit that is the superconducting circuit analog of a mechanical kapitza pendulum. under periodic driving, the emerging qubit states are exponentially protected against bit and phase flips caused by dissipation, which is the primary source of decoherence of current qubits. however, we find that dissipation causes leakage out of the floquet qubit subspace. we engineer a passive cooling scheme to stabilize the qubit subspace, which is crucial for high fidelity quantum control under dissipation. furthermore, we introduce a hardware - efficient fluorescence - based method for qubit measurement and discuss the experimental implementation of the floquet qubit. the proposed kapitzonium is one of the simplest floquet qubits that can be realized with current technology - - and it already has many intriguing features and capabilities. our work provides the first steps to develop more complex floquet quantum systems from the ground up to realize large - scale protected engineered dynamics.
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arxiv:2304.05601
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spin - orbit - torque ( sot ) switching using the spin hall effect ( she ) in heavy metals and topological insulators ( tis ) has great potential for ultra - low power magnetoresistive random - access memory ( mram ). to be competitive with conventional spin - transfer - torque ( stt ) switching, a pure spin current source with large spin hall angle ( $ { \ theta } _ { sh } $ > 1 ) and high electrical conductivity ( $ { \ sigma } > 10 ^ 5 { \ omega } ^ { - 1 } m ^ { - 1 } $ ) is required. here, we demonstrate such a pure spin current source : bisb thin films with $ { \ sigma } { \ sim } 2. 5 * 10 ^ 5 { \ omega } ^ { - 1 } m ^ { - 1 } $, $ { \ theta } _ { sh } { \ sim } 52 $, and spin hall conductivity $ { \ sigma } _ { sh } { \ sim } 1. 3 * 10 ^ 7 { \ hbar } / 2e { \ omega } ^ { - 1 } m ^ { - 1 } $ at room temperature. we show that bisb thin films can generate a colossal spin - orbit field of 2770 oe / ( ma / cm $ ^ 2 $ ) and a critical switching current density as low as 1. 5 ma / cm $ ^ 2 $ in bi $ _ { 0. 9 } $ sb $ _ { 0. 1 } $ / mnga bi - layers. bisb is the best candidate for the first industrial application of topological insulators.
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arxiv:1709.07684
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english to indian language machine translation poses the challenge of structural and morphological divergence. this paper describes english to indian language statistical machine translation using pre - ordering and suffix separation. the pre - ordering uses rules to transfer the structure of the source sentences prior to training and translation. this syntactic restructuring helps statistical machine translation to tackle the structural divergence and hence better translation quality. the suffix separation is used to tackle the morphological divergence between english and highly agglutinative indian languages. we demonstrate that the use of pre - ordering and suffix separation helps in improving the quality of english to indian language machine translation.
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arxiv:1708.07950
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currently, open - domain generative dialog systems have attracted considerable attention in academia and industry. despite the success of single - turn dialog generation, multi - turn dialog generation is still a big challenge. so far, there are two kinds of models for open - domain multi - turn dialog generation : hierarchical and non - hierarchical models. recently, some works have shown that the hierarchical models are better than non - hierarchical models under their experimental settings ; meanwhile, some works also demonstrate the opposite conclusion. due to the lack of adequate comparisons, it ' s not clear which kind of models are better in open - domain multi - turn dialog generation. thus, in this paper, we will measure systematically nearly all representative hierarchical and non - hierarchical models over the same experimental settings to check which kind is better. through extensive experiments, we have the following three important conclusions : ( 1 ) nearly all hierarchical models are worse than non - hierarchical models in open - domain multi - turn dialog generation, except for the hran model. through further analysis, the excellent performance of hran mainly depends on its word - level attention mechanism ; ( 2 ) the performance of other hierarchical models will also obtain a great improvement if integrating the word - level attention mechanism into these models. the modified hierarchical models even significantly outperform the non - hierarchical models ; ( 3 ) the reason why the word - level attention mechanism is so powerful for hierarchical models is because it can leverage context information more effectively, especially the fine - grained information. besides, we have implemented all of the models and already released the codes.
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arxiv:2008.02964
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we discuss the properties of a strongly interacting spin - charge separated one dimensional system coupled to ferromagnets and / or superconductors. our results are valid for arbitrary temperatures with respect to the spin energy, but require temperature be small compared to the charge energy. we focus mainly on the spin - incoherent regime where temperature is large compared to the spin energy, but small compared to the charge energy. in the case of a ferromagnet we study spin pumping and the renormalized dynamics of a precessing magnetic order parameter. we find the interaction - dependent temperature dependence of the spin pumping can be qualitatively different in the spin - incoherent regime from the luttinger liquid regime, allowing an identification of the former. likewise, the temperature dependence of the renormlized magnetization dynamics can be used to identify spin - incoherent physics. for the case of a spin - incoherent luttinger liquid coupled to two superconductors, we compute the ac and dc josephson current for a wire geometry in the limit of tunnel coupled superconductors. both the ac and dc response contain " smoking gun " signatures that can be used to identify spin - incoherent behavior. experimental requirements for the observation of these effects are laid out.
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arxiv:0810.1788
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the topological analysis of biological networks has been a prolific topic in network science during the last decade. a persistent problem with this approach is the inherent uncertainty and noisy nature of the data. one of the cases in which this situation is more marked is that of transcriptional regulatory networks ( trns ) in bacteria. the datasets are incomplete because regulatory pathways associated to a relevant fraction of bacterial genes remain unknown. furthermore, direction, strengths and signs of the links are sometimes unknown or simply overlooked. finally, the experimental approaches to infer the regulations are highly heterogeneous, in a way that induces the appearance of systematic experimental - topological correlations. and yet, the quality of the available data increases constantly. in this work we capitalize on these advances to point out the influence of data ( in ) completeness and quality on some classical results on topological analysis of trns, specially regarding modularity at different levels. in doing so, we identify the most relevant factors affecting the validity of previous findings, highlighting important caveats to future prokaryotic trns topological analysis.
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arxiv:1202.3619
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a small investor provides liquidity at the best bid and ask prices of a limit order market. for small spreads and frequent orders of other market participants, we explicitly determine the investor ' s optimal policy and welfare. in doing so, we allow for general dynamics of the mid price, the spread, and the order flow, as well as for arbitrary preferences of the liquidity provider under consideration.
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arxiv:1309.5235
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we use renormalization group summed perturbation theory ( rgspt ) to improve perturbation series in quantum chromodynamics in the determination of some of the standard model parameters.
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arxiv:2311.06577
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the one - dimensional quasi - geostrophic equation is the one - dimensional fourier - space analogue of the famous navier - stokes equations. in their work li and sinai have proposed a renormalization approach to the problem of existence of finite - time blow up solutions of this equation. in this setting, existence of finite time blow ups is a consequence of existence of a fixed point for a certain renormalization operator on an appropriate functional space. they have provided a proof of existence of complex - valued finite time blow up solutions of the quasi - geostrophic equation. in this paper we revisit the renormalization problem for the quasi - geostrophic blow ups, prove existence of a family of renormalization fixed points, and deduce existence of real $ c ^ \ infty ( [ 0, t ), c ^ \ infty ( \ mathbb { r } ) \ cap l ^ 2 ( \ mathbb { r } ) ) $ solutions to the quasi - geostrophic equation whose energy and enstrophy become unbounded in finite time, different from those found in the previous work of li and sinai.
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arxiv:2203.14651
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we study dynamic nuclear polarization ( dnp ) induced by breakdown of the fractional quantum hall ( fqh ) effect. we find that voltage - current characteristics depend on current sweep rates at the quantum hall states of landau level filling factors $ \ nu $ = 1, 2 / 3, and 1 / 3. the sweep rate dependence is attributed to dnp occurring in the breakdown regime of fqh states. results of a pump and probe experiment show that the polarities of the dnp induced in the breakdown regimes of the fqh states is opposite to that of the dnp induced in the breakdown regimes of odd - integer quantum hall states.
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arxiv:0904.2619
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we present a new method for modeling inhomogeneous cosmic reionization on large scales. utilizing high - resolution radiation - hydrodynamic simulations with 2048 ^ 3 dark matter particles, 2048 ^ 3 gas cells, and 17 billion adaptive rays in a l = 100 mpc / h box, we show that the density and reionization - redshift fields are highly correlated on large scales ( > ~ 1 mpc / h ). this correlation can be statistically represented by a scale - dependent linear bias. we construct a parametric function for the bias, which is then used to filter any large - scale density field to derive the corresponding spatially varying reionization - redshift field. the parametric model has three free parameters which can be reduced to one free parameter when we fit the two bias parameters to simulations results. we can differentiate degenerate combinations of the bias parameters by combining results for the global ionization histories and correlation length between ionized regions. unlike previous semi - analytic models, the evolution of the reionization - redshift field in our model is directly compared cell by cell against simulations and preforms well in all tests. our model maps the high - resolution, intermediate - volume radiation - hydrodynamic simulations onto lower - resolution, larger - volume n - body simulations ( > ~ 2 gpc / h ) in order to make mock observations and theoretical predictions.
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arxiv:1211.2821
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deep neural networks have become a primary tool for solving problems in many fields. they are also used for addressing information retrieval problems and show strong performance in several tasks. training these models requires large, representative datasets and for most ir tasks, such data contains sensitive information from users. privacy and confidentiality concerns prevent many data owners from sharing the data, thus today the research community can only benefit from research on large - scale datasets in a limited manner. in this paper, we discuss privacy preserving mimic learning, i. e., using predictions from a privacy preserving trained model instead of labels from the original sensitive training data as a supervision signal. we present the results of preliminary experiments in which we apply the idea of mimic learning and privacy preserving mimic learning for the task of document re - ranking as one of the core ir tasks. this research is a step toward laying the ground for enabling researchers from data - rich environments to share knowledge learned from actual users ' data, which should facilitate research collaborations.
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arxiv:1707.07605
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in this manuscript, we present analytical solution of the klein - gordon equation with the multi - parameter q - deformed woods - saxon type potential energy under the spin symmetric limit in $ ( 1 + 1 ) $ dimension. in the scattering case, we obtain the reflection and transmission probabilities and prove the conservation of the total probability. moreover, we analyze the correlation between the potential parameters with the reflection and transmission probabilities. in the bound state case, we use the continuity conditions and derive a quantization scheme. to confirm our results numerically, in both cases we randomly assign values to the potential parameters and find numerical results by using the newton raphson method.
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arxiv:1808.03448
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we predict the upper bound on the dissociation temperatures of different quarkonium states.
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arxiv:0707.0182
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the need for knowledge and data discovery management systems ( kddms ) that support ad hoc data mining queries has been long recognized. a significant amount of research has gone into building tightly coupled systems that integrate association rule mining with database systems. in this paper, we describe a seamless integration scheme for database queries and association rule discovery using a common query optimizer for both. query trees of expressions in an extended algebra are used for internal representation in the optimizer. the algebraic representation is flexible enough to deal with constrained association rule queries and other variations of association rule specifications. we propose modularization to simplify the query tree for complex tasks in data mining. it paves the way for making use of existing algorithms for constructing query plans in the optimization process. how the integration scheme we present will facilitate greater user control over the data mining process is also discussed. the work described in this paper forms part of a larger project for fully integrating data mining with database management.
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arxiv:cs/0106055
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t - sne remains one of the most popular embedding techniques for visualizing high - dimensional data. most standard packages of t - sne, such as scikit - learn, use the barnes - hut t - sne ( bh t - sne ) algorithm for large datasets. however, existing cpu implementations of this algorithm are inefficient. in this work, we accelerate the bh t - sne on cpus via cache optimizations, simd, parallelizing sequential steps, and improving parallelization of multithreaded steps. our implementation ( acc - t - sne ) is up to 261x and 4x faster than scikit - learn and the state - of - the - art bh t - sne implementation from daal4py, respectively, on a 32 - core intel ( r ) icelake cloud instance.
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arxiv:2212.11506
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reconfigurable intelligent surface ( ris ) has been regarded as a revolutionary and promising technology owing to its powerful feature of adaptively shaping wireless propagation environment. however, as a frequency - selective device, the ris can only effectively provide tunable phase - shifts for signals within a certain frequency band. thus, base - station ( bs ) - ris - user association is an important issue to maximize the efficiency and ability of the ris in cellular networks. in this paper, we consider a ris - aided cellular network and aim to maximize the sum - rate of downlink transmissions by designing bs - ris - user association as well as the active and passive beamforming of bss and ris, respectively. a dynamically successive access algorithm is developed to design the user association. during the dynamical access process, an iterative algorithm is proposed to alternatively obtain the active and passive beamforming. finally, the optimal bs - ris association is obtained by an exhaustive search method. simulation results illustrate the significant performance improvement of the proposed bs - ris - user association and beamforming design algorithm.
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arxiv:2106.14197
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this work investigates the consequences of assuming that the quantum measurement process - - i. e., the physical realization of a measurement through an interaction between the system to be measured with a measuring device - - is thermodynamically closable, and thus amenable to thermodynamic analysis. our results show that this assumption leads to a fundamental tension between the following three statements : ( i ), the measurement process is consistent with the second and third laws of thermodynamics ; ( ii ), the measurement process is decomposed into two independent sub - processes : a bistochastic interaction between system and measuring device, followed by a readout mechanism on the measuring device ; and ( iii ), the measurement on the system is efficient, i. e., characterized by operations that are completely purity - preserving and represented by a single measurement operator, thus including the von neumann - - l \ " uders and the square - root state reduction rules. any two of the above statements necessarily exclude the third. as a consequence, efficient measurements are fundamentally at odds with the laws of thermodynamics, lest we abandon the universal applicability of the unitary interaction - based indirect measurement model.
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arxiv:2502.14136
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width - based search methods have demonstrated state - of - the - art performance in a wide range of testbeds, from classical planning problems to image - based simulators such as atari games. these methods scale independently of the size of the state - space, but exponentially in the problem width. in practice, running the algorithm with a width larger than 1 is computationally intractable, prohibiting iw from solving higher width problems. in this paper, we present a hierarchical algorithm that plans at two levels of abstraction. a high - level planner uses abstract features that are incrementally discovered from low - level pruning decisions. we illustrate this algorithm in classical planning pddl domains as well as in pixel - based simulator domains. in classical planning, we show how iw ( 1 ) at two levels of abstraction can solve problems of width 2. for pixel - based domains, we show how in combination with a learned policy and a learned value function, the proposed hierarchical iw can outperform current flat iw - based planners in atari games with sparse rewards.
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arxiv:2101.06177
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in the causal set approach to quantum gravity the spacetime continuum arises as an approximation to a fundamentally discrete substructure, the causal set, which is a locally finite partially ordered set. the causal set paradigm was elucidated in a classic paper by bombelli, lee, meyer and sorkin in 1987. while early kinematical results already showed promise, the program received a substantial impetus about a decade ago with the work of rideout and sorkin on a classical stochastic growth dynamics for causal sets. considerable progress has been made ever since in our understanding of causal set theory while leaving undisturbed the basic paradigm. recent highlights include a causal set expression for the einstein - hilbert action and the construction of a scalar field feynman propagator on a fixed causal set. the aim of the present article is to give a broad overview of the results in causal set theory while pointing out directions for future investigations.
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arxiv:1103.6272
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this work aims to investigate some possible emergence of relativistic compact stellar objects in modified $ f ( \ mathcal { g } ) $ gravity using noether symmetry approach. for this purpose, we assume static spherically symmetric spacetime in the presence of isotropic matter distribution. we construct noether symmetry generators along with associated conserved quantities by considering the standard choice of viable $ f ( \ mathcal { g } ) $ gravity model i. e. $ f ( \ mathcal { g } ) = \ alpha \ mathcal { g } ^ { n } $, where $ \ alpha $ is the model parameter. in particular, we use conservation relation acquired from the classical noether approach by imposing some appropriate initial conditions to construct the metric potentials. the obtained conserved quantity play vital role in describing the stellar structure of compact stars. moreover, by considering an appropriate numerical solution, some salient features of compact stellar structures like effective energy density, pressure, energy conditions, stability against equilibrium of the forces and speed of sound are discussed by assigning the suitable values of model parameter involved. our study reveals that the compact objects in $ f ( \ mathcal { g } ) $ gravity from noether symmetry approach depend on the conserved quantity obtained and the model parameter $ \ alpha $. in nutshell, noether symmetries are quite helpful to generate solutions that follow physically accepted phenomena. moreover, we observed that these obtained solutions are consistent with the astrophysical observational data, which depicts the viability of our proposed noether symmetry scheme.
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arxiv:2006.03339
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standard informativeness measures used to evaluate automatic text summarization mostly rely on n - gram overlapping between the automatic summary and the reference summaries. these measures differ from the metric they use ( cosine, rouge, kullback - leibler, logarithm similarity, etc. ) and the bag of terms they consider ( single words, word n - grams, entities, nuggets, etc. ). recent word embedding approaches offer a continuous alternative to discrete approaches based on the presence / absence of a text unit. informativeness measures have been extended to focus information retrieval evaluation involving a user ' s information need represented by short queries. in particular for the task of clef - inex tweet contextualization, tweet contents have been considered as queries. in this paper we define the concept of interestingness as a generalization of informativeness, whereby the information need is diverse and formalized as an unknown set of implicit queries. we then study the ability of state of the art informativeness measures to cope with this generalization. lately we show that with this new framework, standard word embeddings outperforms discrete measures only on uni - grams, however bi - grams seems to be a key point of interestingness evaluation. lastly we prove that the clef - inex tweet contextualization 2012 logarithm similarity measure provides best results.
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arxiv:2004.06747
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we consider the scattering of two - bosons with negative parity and spin 0 or 1. starting from helicity partial - wave scattering amplitudes we derive transformations that eliminate all kinematical constraints. such amplitudes are expected to satisfy partial - wave dispersion relations and therefore provide a suitable basis for data analysis and the construction of effective field theories. our derivation relies on a decomposition of the various scattering amplitudes into suitable sets of invariant functions. a novel algebra was developed that permits the efficient computation of such functions in terms of computer algebra codes.
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arxiv:1111.1838
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we provide a new general setting for scalar interacting fields on the covering of a d + 1 - dimensional ads spacetime. the formalism is used at first to construct a one - paramater family of field theories, each living on a corresponding spacetime submanifold of ads, which is a cylinder $ r \ times s _ { d - 1 } $. we then introduce a limiting procedure which directly produces luescher - mack cft ' s on the covering of the ads asymptotic cone. our ads / cft correspondence is generally valid for interacting fields, and is illustrated by a complete treatment of two - point functions, the case of klein - gordon fields appearing as particularly simple in our context. we also show how the minkowskian representation of these boundary cft ' s can be directly generated by an alternative limiting procedure involving minkowskian theories in horocyclic sections ( nowadays called ( d - 1 ) - branes, 3 - branes for ads _ 5 ). these theories are restrictions to the brane of the ambient ads field theory considered. this provides a more general correspondence between the ads field theory and a poincare ' invariant qft on the brane, satisfying all the wightman axioms. the case of two - point functions is again studied in detail from this viewpoint as well as the cft limit on the boundary.
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arxiv:hep-th/9908140
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a $ k $ - graph system $ \ textbf { h } = \ { h _ i \ } _ { i \ in [ m ] } $ is a family of not necessarily distinct $ k $ - graphs on the same $ n $ - vertex set $ v $ and a $ k $ - graph $ h $ on $ v $ is said to be $ \ textbf { h } $ - transversal provided that there exists an injection $ \ varphi : e ( h ) \ rightarrow [ m ] $ such that $ e \ in e ( h _ { \ varphi ( e ) } ) $ for all $ e \ in e ( h ) $. we show that given $ k \ geq3, \ gamma > 0 $, sufficiently large $ n $ and an $ n $ - vertex $ k $ - graph system $ \ textbf { h } = \ { h _ i \ } _ { i \ in [ n ] } $, if $ \ delta _ { k - 1 } ( h _ i ) \ geq ( 1 / 2 + \ gamma ) n $ for each $ i \ in [ n ] $, then there exists an $ \ textbf { h } $ - transversal tight hamilton cycle. this extends the result of r \ " { o } dl, ruci \ ' { n } ski and szemer \ ' { e } di [ combinatorica, 2008 ] on single $ k $ - graphs.
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arxiv:2111.07079
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unpredictability, or randomness, of the outcomes of measurements made on an entangled state can be certified provided that the statistics violate a bell inequality. in the standard bell scenario where each party performs a single measurement on its share of the system, only a finite amount of randomness, of at most $ 4 log _ 2 d $ bits, can be certified from a pair of entangled particles of dimension $ d $. our work shows that this fundamental limitation can be overcome using sequences of ( nonprojective ) measurements on the same system. more precisely, we prove that one can certify any amount of random bits from a pair of qubits in a pure state as the resource, even if it is arbitrarily weakly entangled. in addition, this certification is achieved by near - maximal violation of a particular bell inequality for each measurement in the sequence.
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arxiv:1510.03394
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of objective research or statistical hypothesis testing. a mathematical model uses mathematical language to describe a system. the process of developing a mathematical model is termed ' mathematical modelling ' ( also modeling ). a mathematical model is " a representation of the essential aspects of an existing system ( or a system to be constructed ) that presents knowledge of that system in usable form ". mathematical models can take many forms, including but not limited to dynamical systems, statistical models, differential equations, or game theoretic models. these and other types of models can overlap, with a given model involving a variety of abstract structures. the system is a set of interacting or interdependent entities, real or abstract, forming an integrated whole. the concept of an integrated whole can also be stated in terms of a system embodying a set of relationships that are differentiated from relationships of the set to other elements, and from relationships between an element of the set and elements not a part of the relational regime. a dynamical system modeled as a mathematical formalization has a fixed " rule " that describes the time dependence of a point ' s position in its ambient space. small changes in the state of the system correspond to small changes in the numbers. the evolution rule of the dynamical system is a fixed rule that describes what future states follow from the current state. the rule is deterministic : for a given time interval only one future state follows from the current state. social scientists often conduct program evaluation, which is a systematic method for collecting, analyzing, and using information to answer questions about projects, policies and programs, particularly about their effectiveness and efficiency. in both the public and private sectors, stakeholders often want to know whether the programs they are funding, implementing, voting for, receiving or objecting to are producing the intended effect. while program evaluation first focuses around this definition, important considerations often include how much the program costs per participant, how the program could be improved, whether the program is worthwhile, whether there are better alternatives, if there are unintended outcomes, and whether the program goals are appropriate and useful. = = = theory = = = some social theorists emphasize the subjective nature of research. these writers espouse social theory perspectives that include various types of the following : critical theory is the examination and critique of society and culture, drawing from knowledge across social sciences and humanities disciplines. dialectical materialism is the philosophy of karl marx, which he formulated by taking the dialectic of hegel and joining it to the materialism of feuerbach. feminist theory
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https://en.wikipedia.org/wiki/Social_science
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the sunspot solar cycle has been usually explained as the result of a dynamo process operating in the sun. this is a classical problem in astrophysics that until the present is not fully solved. here we discuss current problems and limitations with the solar dynamo modeling and their possible solutions using a kinematic dynamo model within the babcock - leighton approximation as a tool. in particular, we discuss the importance of the turbulent magnetic pumping versus the meridional flow circulation in the dynamo operation.
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arxiv:0812.1169
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we show that for every $ 0 < \ epsilon \ leq 1 $ and integer $ k \ geq 1 $, there exists an integer $ n = n ( \ epsilon, k ) $ so that for all primes $ p $, and integers $ 0 \ leq a \ leq p - 1 $, there exist integers $ 1 \ leq x _ 1 <... < x _ n \ leq p ^ \ epsilon $ such that $ a \ equiv x _ 1 ^ { - 1 } +... + x _ n ^ { - 1 } \ pmod { p } $. this extends a result of i. shparlinski.
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arxiv:math/0403360
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we formulate minimal supergeometric quantum field theories ( sg - qfts ) that allow for scalar - fermion field transformations in a manifestly reparameterisation covariant manner. first, we discuss the issue of uniqueness in defining the field - space supermetric of the underlying supermanifold, and clarify the fact that different supermetric definitions can lead to distinct theories in the off - shell kinematic region. by adopting natural choices for the field - space supermetric, we ~ then show that scalar fields alone cannot induce a non - trivial field - space riemannian curvature in the fermionic sector, beyond the one originating from the scalar part of the theory. we ~ present for the first time minimal sg - qft models that feature non - zero fermionic curvature both in two and four spacetime dimensions. physical applications of sg - qfts are discussed.
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arxiv:2307.01126
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we propose a multi - scale approach to understand the physics related to ion - beam cancer therapy. it allows the calculation of the probability of dna damage as a result of irradiation of tissues with energetic ions, up to 430 mev / u. this approach covers different scales, starting from the large scale, defined by the ion stopping, followed by a smaller scale, defined by secondary electrons and radicals, and ending with the shortest scale, defined by interactions of secondaries with the dna. we present calculations of the probabilities of single and double strand breaks of dna, suggest a way to further expand such calculations, and also make some estimates for glial cells exposed to radiation.
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arxiv:0811.0988
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motivated by the study of soluble models of quantum field theory, we illustrate a new type of topological effect by comparing the constructions of canonical klein - gordon quantum fields on the two - dimensional de sitter spacetime as opposed to its double covering. we show that the while commutators of the two fields coincide locally, the global topological differences make the theories drastically different. many of the well - known features of de sitter quantum field theory disappear. in particular there is nothing like a bunch - davies vacuum. correspondingly, even though the local horizon structure is the same for the two universes there is no hawking - gibbons thermal state. finally, there is no complementary series of fields.
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arxiv:1901.10874
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deploying federated learning ( fl ) over wireless networks with resource - constrained devices requires balancing between accuracy, energy efficiency, and precision. prior art on fl often requires devices to train deep neural networks ( dnns ) using a 32 - bit precision level for data representation to improve accuracy. however, such algorithms are impractical for resource - constrained devices since dnns could require execution of millions of operations. thus, training dnns with a high precision level incurs a high energy cost for fl. in this paper, a quantized fl framework, that represents data with a finite level of precision in both local training and uplink transmission, is proposed. here, the finite level of precision is captured through the use of quantized neural networks ( qnns ) that quantize weights and activations in fixed - precision format. in the considered fl model, each device trains its qnn and transmits a quantized training result to the base station. energy models for the local training and the transmission with the quantization are rigorously derived. an energy minimization problem is formulated with respect to the level of precision while ensuring convergence. to solve the problem, we first analytically derive the fl convergence rate and use a line search method. simulation results show that our fl framework can reduce energy consumption by up to 53 % compared to a standard fl model. the results also shed light on the tradeoff between precision, energy, and accuracy in fl over wireless networks.
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arxiv:2111.07911
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we present the preliminary results from our analysis of event by event fluctuation in k / pi ratio in au + au collision at \ sqrt s _ { nn } = 200 gev and at 62. 4 gev using star detector at rhic. two different methods have been used to extract the strength of dynamical fluctuation and the centrality dependence of that. the results from the study of energy and centrality dependence of the dynamical fluctuation are presented. from the excitation function it is seen that at two rhic energies the measure of dynamical fluctuation is constant with values very close to that at 12. 3 gev at sps. the dynamical fluctuation is found to be positive and decreasing with increasing centrality at rhic. the results are compared with hijing model calculation with jets. results from hijing are found to be very close to data from central collisions whereas it over predicts the data for peripheral events.
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arxiv:nucl-ex/0503023
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in supervised learning, including regression and classification, conformal methods provide prediction sets for the outcome / label with finite sample coverage for any machine learning predictor. we consider here the case where such prediction sets come after a selection process. the selection process requires that the selected prediction sets be ` informative ' in a well defined sense. we consider both the classification and regression settings where the analyst may consider as informative only the sample with prediction sets small enough, excluding null values, or obeying other appropriate ` monotone ' constraints. we develop a unified framework for building such informative conformal prediction sets while controlling the false coverage rate ( fcr ) on the selected sample. while conformal prediction sets after selection have been the focus of much recent literature in the field, the new introduced procedures, called infosp and infoscop, are to our knowledge the first ones providing fcr control for informative prediction sets. we show the usefulness of our resulting procedures on real and simulated data.
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arxiv:2403.12295
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the transfer of high - precision optical frequency signals over free - space links, particularly between ground stations and satellites, will enable advances in fields ranging from coherent optical communications and satellite doppler ranging to tests of general relativity and fundamental physics. we present results for the actively stabilized coherent phase transfer of a 193 thz continuous wave optical frequency signal over horizontal free - space links 150 m and 600 m in length. over the 600 m link we achieved a fractional frequency stability of 8. 9e - 18 at one second of integration time, improving to 1. 3e - 18 at an integration time of 64 s, suitable for transmission of optical atomic clock signals. the achievable transfer distance is limited by deep - fading of the transmitted signal due to atmospheric turbulence. we also estimate the expected additional degradation in stability performance for frequency transfer to low earth orbit.
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arxiv:1806.00945
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in this work, we present independent determinations of cosmological parameters and new constraints on $ f ( t ) $ cosmologies, employing two new catalogs related to hii galaxy hubble and cmb distance priors, along with the local standard measurements, snia, $ h ( z ) $ measurements, growth rate data ( rsd ), and bao baselines. we found that the marginalised best - fit c. l. $ h _ 0 $ and $ \ sigma _ 8 $ parameters within these cosmologies can relax the current cosmological tensions using hiig data. this produces a larger range of admissible values for the current hubble constant, and when all baselines are considered, the uncertainty bands for $ h _ 0 $ and the matter density parameter reduce significantly.
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arxiv:2405.06633
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one underlying assumption of recent federated learning ( fl ) paradigms is that all local models usually share the same network architecture and size, which becomes impractical for devices with different hardware resources. a scalable federated learning framework should address the heterogeneity that clients have different computing capacities and communication capabilities. to this end, this paper proposes fedhm, a novel heterogeneous federated model compression framework, distributing the heterogeneous low - rank models to clients and then aggregating them into a full - rank model. our solution enables the training of heterogeneous models with varying computational complexities and aggregates them into a single global model. furthermore, fedhm significantly reduces the communication cost by using low - rank models. extensive experimental results demonstrate that fedhm is superior in the performance and robustness of models of different sizes, compared with state - of - the - art heterogeneous fl methods under various fl settings. additionally, the convergence guarantee of fl for heterogeneous devices is first theoretically analyzed.
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arxiv:2111.14655
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recent works combining neutrino oscillation and cosmological data to determine the neutrino hierarchy found a range of odds in favour of the normal hierarchy. these results arise from differing approaches to incorporating prior knowledge about neutrinos. we develop a hierarchy - agnostic prior and show that the hierarchy cannot be conclusively determined with current data. the determination of the hierarchy is limited by the neutrino mass scale $ \ sigma _ { \ nu } $ measurement. we obtain a target precision of $ \ sigma ( \ sigma _ { \ nu } ) = 0. 014 $ ev, necessary for conclusively establishing the normal hierarchy with future data.
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arxiv:1907.04331
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we give a geometric derivation of sle ( $ \ kappa, \ rho $ ) in terms of conformally invariant random growing subsets of polygons. we relate the parameters $ \ rho _ j $ to the exterior angles of the polygons. we also show that sle ( $ \ kappa, \ rho $ ) can be generated by a metric brownian motion, where metric and brownian motion are coupled and the metric ist the pull - back metric of the euclidean metric of an evolving polygon.
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arxiv:math/0506062
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we present the results of a line identification analysis using data from the iram plateau de bure inferferometer, focusing on six massive star - forming hot cores : g31. 41 + 0. 31, g29. 96 - 0. 02, g19. 61 - 0. 23, g10. 62 - 0. 38, g24. 78 + 0. 08a1 and g24. 78 + 0. 08a2. we identify several transitions of vibrationally excited methyl formate ( hcooch $ _ 3 $ ) for the first time in these objects as well as transitions of other complex molecules, including ethyl cyanide ( c $ _ 2 $ h $ _ 5 $ cn ), and isocyanic acid ( hnco ). we also postulate a detection of one transition of glycolaldehyde ( ch $ _ 2 $ ( oh ) cho ) in two new hot cores. we find g29. 96 - 0. 02, g19. 61 - 0. 23, g24. 78 + 0. 08a1 and 24. 78 + 0. 08a2 to be chemically very similar. g31. 41 + 0. 31, however, is chemically different : it manifests a larger chemical inventory and has significantly larger column densities. we suggest that it may represent a different evolutionary stage to the other hot cores in the sample, or it may surround a star with a higher mass. we derive column densities for methyl formate in g31. 41 + 0. 31, using the rotation diagram method, of $ \ times $ 10 $ ^ { 17 } $ cm $ ^ { - 2 } $ and a t $ _ { rot } $ of $ \ sim $ 170 k. for g29. 96 - 0. 02, g24. 78 + 0. 08a1 and g24. 78 + 0. 08a2, glycolaldehyde, methyl formate and methyl cyanide all seem to trace the same material and peak at roughly the same position towards the dust emission peak. for g31. 41 + 0. 31, however, glycolaldehyde shows a different distribution to methyl formate and methyl cyanide and seems to trace the densest, most compact inner part of hot cores.
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arxiv:1407.1661
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in the framework of berthelot ' s theory of arithmetic $ \ mathcal { d } $ - modules, we introduce the notion of arithmetic $ \ mathcal { d } $ - modules having potentially - unipotent monodromy. for example, from kedlaya ' s semistable reduction theorem, overconvergent isocrystals with frobenius structure have potentially unipotent monodromy. we construct some coefficients stable under grothendieck ' s six operation, containing overconvergent isocrystals with frobenius structure and whose object have potentially unipotent monodromy. on the other hand, we introduce the notion of arithmetic $ \ mathcal { d } $ - modules having quasi - unipotent monodromy. these objects are overholonomic, contain the isocrystals having potentially unipotent monodromy and are stable under grothendieck ' s six operations and under base change.
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arxiv:1404.5856
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it has now become recognised that damped lyman alpha systems play an important role in helping us unravel the origin of chemical elements. in this presentation, we describe the main results of a recently completed survey of the most metal - poor dlas, aimed at complementing and extending studies of the oldest stars in the galaxy. the survey has clarified a number of lingering issues concerning the abundances of c, n, o in the low metallicity regime, has revealed the existence of dla analogues to carbon - enhanced metal - poor stars, and is providing some of the most precise measures of the primordial abundance of deuterium.
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arxiv:1209.4783
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we have obtained k - band multi - object spectrograph ( kmos ) near - ir spectroscopy for 14 red supergiant stars ( rsgs ) in the young massive star cluster ngc 2100 in the large magellanic cloud ( lmc ). stellar parameters including metallicity are estimated using the j - band analysis technique, which has been rigorously tested in the local universe. we find an average metallicity for ngc 2100 of [ z ] = $ - $ 0. 43 $ \ pm $ 0. 10 dex, in good agreement with estimates from the literature for the lmc. comparing our results in ngc 2100 with those for a galactic cluster ( at solar - like metallicity ) with a similar mass and age we find no significant difference in the location of rsgs in the hertzsprung - - russell diagram. we combine the observed kmos spectra to form a simulated integrated - light cluster spectrum and show that, by analysing this spectrum as a single rsg, the results are consistent with the average properties of the cluster. radial velocities are estimated for the targets and the dynamical properties are estimated for the first time within this cluster. the data are consistent with a flat velocity dispersion profile, and with an upper limit of 3. 9 km / s, at the 95 % confidence level, for the velocity dispersion of the cluster. however, the intrinsic velocity dispersion is unresolved and could, therefore, be significantly smaller than the upper limit reported here. an upper limit on the dynamical mass of the cluster is derived as $ m _ { dyn } $ $ \ le $ $ 15. 2 \ times10 ^ { 4 } m _ { \ odot } $ assuming virial equilibrium.
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arxiv:1602.02702
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the natural bmo ( bounded mean oscillation ) conditions suggested by scalar - valued results are known to be insufficient for the boundedness of operator - valued paraproducts. accordingly, the boundedness of operator - valued singular integrals has only been available under versions of the classical ` ` $ t ( 1 ) \ in bmo $ ' ' assumptions that are not easily checkable. recently, hong, liu and mei ( j. funct. anal. 2020 ) observed that the situation improves remarkably for singular integrals with a symmetry assumption, so that a classical $ t ( 1 ) $ criterion still guarantees their $ l ^ 2 $ - boundedness on hilbert space - valued functions. here, these results are extended to general umd ( unconditional martingale differences ) spaces with the same natural bmo condition for symmetrised paraproducts, and requiring in addition only the usual replacement of uniform bounds by $ r $ - bounds in the case of general singular integrals. in particular, under these assumptions, we obtain boundedness results on non - commutative $ l ^ p $ spaces for all $ 1 < p < \ infty $, without the need to replace the domain or the target by a related non - commutative hardy space as in the results of hong et al. for $ p \ neq 2 $.
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arxiv:2008.04143
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in the absence of pharmaceutical interventions to curb the spread of covid - 19, countries relied on a number of nonpharmaceutical interventions to fight the first wave of the pandemic. the most prevalent one has been stay - at - home orders, whose the goal is to limit the physical contact between people, which consequently will reduce the number of secondary infections generated. in this work, we use a detailed set of mobility data to evaluate the impact that these interventions had on alleviating the spread of the virus in the us as measured through the covid - 19 - related deaths. to establish this impact, we use the notion of granger causality between two time - series. we show that there is a unidirectional granger causality, from the median percentage of time spent daily at home to the daily number of covid - 19 - related deaths with a lag of 2 weeks. we further analyze the mobility patterns at the census block level to identify which parts of the population might encounter difficulties in adhering and complying with social distancing measures. this information is important, since it can consequently drive interventions that aim at helping these parts of the population.
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arxiv:2006.12720
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in this work, we study the thermodynamic topology of a static, a charged static and a charged, rotating black hole in $ f ( r ) $ gravity. for charged static black holes, we work in two different ensembles : fixed charge $ ( q ) $ ensemble and fixed potential $ ( \ phi ) $ ensemble. for charged, rotating black hole, four different types of ensembles are considered : fixed $ ( q, j ) $, fixed $ ( \ phi, j ) $, fixed $ ( q, \ omega ) $ and fixed $ ( \ phi, \ omega ) $ ensemble, where $ j $ and $ \ omega $ denotes the angular momentum and the angular frequency respectively. using the generalized off - shell free energy method, where the black holes are treated as topological defects in their thermodynamic spaces, we investigate the local and global topology of these black holes via the computation of winding numbers at these defects. for static black hole we work in three model. we find that the topological charge for a static black hole is always $ - 1 $ regardless of the values of the thermodynamic parameters and the choice of $ f ( r ) $ model. for a charged static black hole, in the fixed charge ensemble, the topological charge is found to be zero. contrastingly, in the fixed $ \ phi $ ensemble, the topological charge is found to be $ - 1. $ for charged static black holes, in both the ensembles, the topological charge is observed to be independent of the thermodynamic parameters. for charged, rotating black hole, in fixed $ ( q, j ) $ ensemble, the topological charge is found to be $ 1. $ in $ ( \ phi, j ) $ ensemble, we find the topological charge to be $ 1. $ in case of fixed $ ( q, \ omega ) $ ensemble, the topological charge is $ 1 $ or $ 0 $ depending on the value of the scalar curvature ( $ r $ ). in fixed $ ( \ omega, \ phi ) $ ensemble, the topological charge is $ - 1, 0 $ or $ 1 $ depending on the values of $ r, \ omega $ and $ \ phi. $
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arxiv:2401.16756
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unsupervised image - to - image translation is an inherently ill - posed problem. recent methods based on deep encoder - decoder architectures have shown impressive results, but we show that they only succeed due to a strong locality bias, and they fail to learn very simple nonlocal transformations ( e. g. mapping upside down faces to upright faces ). when the locality bias is removed, the methods are too powerful and may fail to learn simple local transformations. in this paper we introduce linear encoder - decoder architectures for unsupervised image to image translation. we show that learning is much easier and faster with these architectures and yet the results are surprisingly effective. in particular, we show a number of local problems for which the results of the linear methods are comparable to those of state - of - the - art architectures but with a fraction of the training time, and a number of nonlocal problems for which the state - of - the - art fails while linear methods succeed.
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arxiv:2007.12568
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the fields of experts ( foe ) image prior model, a filter - based higher - order markov random fields ( mrf ) model, has been shown to be effective for many image restoration problems. motivated by the successes of foe - based approaches, in this letter, we propose a novel variational model for multiplicative noise reduction based on the foe image prior model. the resulted model corresponds to a non - convex minimization problem, which can be solved by a recently published non - convex optimization algorithm. experimental results based on synthetic speckle noise and real synthetic aperture radar ( sar ) images suggest that the performance of our proposed method is on par with the best published despeckling algorithm. besides, our proposed model comes along with an additional advantage, that the inference is extremely efficient. { our gpu based implementation takes less than 1s to produce state - of - the - art despeckling performance. }
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arxiv:1404.5344
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we consider solvable matrix models. we generalize harish - chandra - itzykson - zuber and certain other integrals ( gross - witten integral and integrals over complex matrices ) using the notion of tau function of matrix argument. in this case one can reduce the matrix integral to the integral over eigenvalues, which in turn is certain tau function. the resulting tau function may be analyzed either by the method of orthogonal polynomials or by the schur functions expansion method.
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arxiv:math-ph/0210012
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single dopants in semiconductor nanostructures have been studied in great details recently as they are good candidates for quantum bits, provided they are coupled to a detector. here we report coupling of a single as donor atom to a single - electron transistor ( set ) in a silicon nanowire field - effect transistor. both capacitive and tunnel coupling are achieved, the latter resulting in a dramatic increase of the conductance through the set, by up to one order of magnitude. the experimental results are well explained by the rate equations theory developed in parallel with the experiment.
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arxiv:1012.5544
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this article examines the evolution of cryptologic techniques and their implications for public and private security, focusing on the italian and eu legal frameworks. it explores the roles of cryptography, steganography, and quantum technologies in countering cybersecurity threats, emphasising the need for robust legislation to address emerging challenges. special attention is given to italy ' s legislative reforms, including law no. 90 of 2024, which strengthens penalties for cybercrimes and establishes the national cryptography centre within the italian national cybersecurity agency. additionally, the article highlights international initiatives, such as the un ' s draft convention on cybercrime, emphasising the balance between security, privacy, and fundamental human rights in a post - quantum era.
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arxiv:2505.08650
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for each pair $ ( e, \ sigma ) $ of integers satisfying $ 2e + 3 \ sigma \ ge 0 $, $ \ sigma \ leq - 2 $, and $ e + \ sigma \ equiv 0 \ pmod { 4 } $, with four exceptions, we construct a minimal, simply connected symplectic 4 - manifold with euler characteristic $ e $ and signature $ \ sigma $. we also produce simply connected, minimal symplectic 4 - manifolds with signature zero ( resp. signature - 1 ) with euler characteristic $ 4k $ ( resp. $ 4k + 1 $ ) for all $ k \ ge 46 $ ( resp. $ k \ ge 49 $ ).
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arxiv:0705.0778
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inspired by pansiot ' s work on substitutions, we prove a similar theorem for automorphisms of a free group f of finite rank : if a right - infinite word represents an attracting fixed point of an automorphism of f, the subword complexity of x is equivalent to n, n log log n, n log n, or n ^ 2. the proof uses combinatorial arguments analogue to pansiot ' s as well as train tracks. we also define the recurrence complexity of x, and we apply it to laminations. in particular, we show that attracting laminations have complexity equivalent to n, n log log n, n log n, or n ^ 2 ( to n if the automorphism is fully irreducible ).
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arxiv:2208.00676
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all known five dimensional, asymptotically flat, static black rings possess conical singularities. however, there is no fundamental obstruction forbidding the existence of balanced configurations, and we show that the einstein - - klein - gordon equations admit ( numerical ) solutions describing static asymptotically flat black rings, which are regular on and outside the event horizon. the scalar field is ' phantom ', which creates the self - repulsion necessary to balance the black rings. similar solutions are likely to exist in other spacetime dimensions, the basic properties of a line element describing a four dimensional, asymptotically flat black ring geometry being discussed.
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arxiv:1906.06372
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we study a ( relativistic ) wiener process on a complexified ( pseudo - ) riemannian manifold. using nelson ' s stochastic quantization procedure, we derive three equivalent descriptions for this problem. if the process has a purely real quadratic variation, we obtain the one - sided wiener process that is encountered in the theory of brownian motion. in this case, the result coincides with the feyman - kac formula. on the other hand, for a purely imaginary quadratic variation, we obtain the two - sided wiener process that is encountered in stochastic mechanics, which provides a stochastic description of a quantum particle on a curved spacetime.
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arxiv:2109.10710
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this paper presents a model - free data - driven strategy for linear and non - linear finite element computations of open - cell foam. employing sets of material data, the data - driven problem is formulated as the minimization of a distance function subjected to the physical constraints from the kinematics and the balance laws of the mechanical problem. the material data sets of the foam are deduced here from representative microscopic material volumes. these volume elements capture the stochastic characteristics of the open - cell microstructure and the properties of the polyurethane material. their computation provides the required stress - strain data used in the macroscopic finite element computations without postulating a specific constitutive model. the paper shows how to efficiently derive suitable material data sets for the different ( non - ) linear and ( an - ) isotropic material behavior cases. exemplarily, we compare data - driven finite element computations with linearized and finite deformations and show that a linear kinematic is sufficiently accurate to capture the material ' s non - linearity up to 50 % of straining. the numerical example of a rubber sealing illustrates possible areas of application, the expenditure, and the proposed strategy ' s versatility.
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arxiv:2110.11129
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bilinear pooling ( blp ) refers to a family of operations recently developed for fusing features from different modalities predominantly developed for vqa models. a bilinear ( outer - product ) expansion is thought to encourage models to learn interactions between two feature spaces and has experimentally outperformed ` simpler ' vector operations ( concatenation and element - wise - addition / multiplication ) on vqa benchmarks. successive blp techniques have yielded higher performance with lower computational expense and are often implemented alongside attention mechanisms. however, despite significant progress in vqa, blp methods have not been widely applied to more recently explored video question answering ( video - qa ) tasks. in this paper, we begin to bridge this research gap by applying blp techniques to various video - qa benchmarks, namely : tvqa, tgif - qa, ego - vqa and msvd - qa. we share our results on the tvqa baseline model, and the recently proposed heterogeneous - memory - enchanced multimodal attention ( hme ) model. our experiments include both simply replacing feature concatenation in the existing models with blp, and a modified version of the tvqa baseline to accommodate blp we name the ` dual - stream ' model. we find that our relatively simple integration of blp does not increase, and mostly harms, performance on these video - qa benchmarks. using recently proposed theoretical multimodal fusion taxonomies, we offer insight into why blp - driven performance gain for video - qa benchmarks may be more difficult to achieve than in earlier vqa models. we suggest a few additional ` best - practices ' to consider when applying blp to video - qa. we stress that video - qa models should carefully consider where the complex representational potential from blp is actually needed to avoid computational expense on ` redundant ' fusion.
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arxiv:2012.10285
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the literature dealing with g \ " { o } del ' s legacy is largely preoccupied with challenging his philosophical views, regarding them as outdated. we believe that such an approach prevents us from seeing g \ " { o } del ' s views in the right light and understanding their rationale. in this article, his views are discussed in the philosophical realm in which he himself understood them. we explore the consequences of g \ " { o } del ' s incompleteness theorems for the question of the objectivity of mathematics and its epistemology. taking set theory as the paradigm of formal mathematical theories, we examine the relationship between its incompleteness and extensionality. we argue, based on his philosophical views, that g \ " { o } del believed incompleteness can be overcome only by some intensional considerations about concepts from the basis of mathematical theories. these considerations should eventually lead to founding the so - called logic of concepts.
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arxiv:2406.05442
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we study the geometric structure of poncelet $ n $ - gons from a projective point of view. in particular we present explicit constructions of poncelet $ n $ - gons for certain $ n $ and derive algebraic characterisations in terms of bracket polynomials. via the connections of poncelet polygons and $ ( n _ 4 ) $ - configurations, the results of this article can be used to construct a large class of specific movable $ ( n _ 4 ) $ - configurations, the trivial celestial 4 - configurations, which up to this point were all thought to be rigid and to require regular polygons for their construction.
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arxiv:2408.09225
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we investigate single - particle properties of a one - component fermi gas with a tunable p - wave interaction. including pairing fluctuations associated with this anisotropic interaction within a $ t $ - matrix theory, we calculate the single - particle density of states, as well as the spectral weight, above the superfluid transition temperature $ t _ { \ rm c } $. starting from the weak - coupling regime, we show that the so - called pseudogap first develops in these quantities with increasing the interaction strength. however, when the interaction becomes strong to some extent, the pseudogap becomes obscure to eventually disappear in the strong - coupling regime. this non - monotonic interaction dependence is quite different from the case of an s - wave interaction, where the pseudogap simply develops with increasing the interaction strength. the difference between the two cases is shown to originate from the momentum dependence of the p - wave interaction, which vanishes in the low momentum limit. we also identify the pseudogap regime in the phase diagram with respect to the temperature and the p - wave interaction strength. since the pseudogap is a precursor phenomenon of the superfluid phase transition, our results would be useful for the research toward the realization of p - wave superfluid fermi gases.
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arxiv:1202.5353
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this paper investigates a stochastic linear - quadratic ( slq, for short ) control problem regulated by a time - invariant markov chain in infinite horizon. under the $ l ^ 2 $ - stability framework, we study a class of linear backward stochastic differential equations ( bsde, for short ) in infinite horizon and discuss the open - loop and closed - loop solvabilities of the slq problem. the open - loop solvability is characterized by the solvability of a system of coupled forward - backward stochastic differential equations ( fbsdes, for short ) in infinite horizon and the convexity of the cost functional, and the closed - loop solvability is shown to be equivalent to the open - loop solvability, which in turn is equivalent to the existence of a static stabilizing solution to the associated constrained coupled algebra riccati equations ( cares, for short ). under the uniform convexity assumption, we obtain the unique solvability of associated cares and construct the corresponding closed - loop optimal strategy. finally, we also solve a class of discounted slq problems and give two concrete examples to illustrate the results developed in the earlier sections.
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arxiv:2403.00288
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constant is called the coefficient of proportionality or proportionality constant. if one quantity is always the product of the other and a constant, the two are said to be directly proportional. x and y are directly proportional if the ratio y x { \ displaystyle { \ tfrac { y } { x } } } is constant. if the product of the two quantities is always equal to a constant, the two are said to be inversely proportional. x and y are inversely proportional if the product x y { \ displaystyle xy } is constant. = = = analytic geometry = = = analytic geometry is the study of geometry using a coordinate system. this contrasts with synthetic geometry. usually the cartesian coordinate system is applied to manipulate equations for planes, straight lines, and squares, often in two and sometimes in three dimensions. geometrically, one studies the euclidean plane ( 2 dimensions ) and euclidean space ( 3 dimensions ). as taught in school books, analytic geometry can be explained more simply : it is concerned with defining and representing geometrical shapes in a numerical way and extracting numerical information from shapes ' numerical definitions and representations. transformations are ways of shifting and scaling functions using different algebraic formulas. = = = negative numbers = = = a negative number is a real number that is less than zero. such numbers are often used to represent the amount of a loss or absence. for example, a debt that is owed may be thought of as a negative asset, or a decrease in some quantity may be thought of as a negative increase. negative numbers are used to describe values on a scale that goes below zero, such as the celsius and fahrenheit scales for temperature. = = = exponents and radicals = = = exponentiation is a mathematical operation, written as bn, involving two numbers, the base b and the exponent ( or power ) n. when n is a natural number ( i. e., a positive integer ), exponentiation corresponds to repeated multiplication of the base : that is, bn is the product of multiplying n bases : b n = b Γ Γ b n { \ displaystyle b ^ { n } = \ underbrace { b \ times \ cdots \ times b } _ { n } } roots are the opposite of exponents. the nth root of a number x ( written x n { \ displaystyle { \ sqrt [ { n } ] { x } } } ) is a number r which when raised to the power
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https://en.wikipedia.org/wiki/Elementary_mathematics
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for high energy cosmic neutrinos athar, jezabek, and yasuda ( ajy ) have recently shown that the existing data on neutrino oscillations suggests that cosmic neutrino flux at the agn / grb source, f ( nu _ e ) : f ( nu _ mu ) : f ( nu _ tau ) approx 1 : 2 : 0, oscillates to f ( nu _ e ) : f ( nu _ mu ) : f ( nu _ tau ) approx 1 : 1 : 1. these results can be confirmed at amanda, baikal, antares and nestor, and other neutrino detectors with a good flavor resolution. here, we re - derive the ajy result from quasi bi - maximal mixing, and show that observation of f ( nu _ e ) : f ( nu _ \ mu ) : f ( nu _ tau ) approx 1 : 1 : 1 does not necessarily establish cosmic neutrino flux at the agn / grb source to be f ( nu _ e ) : f ( nu _ mu ) : f ( nu _ tau ) approx 1 : 2 : 0.
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arxiv:hep-ph/0006092
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we present the observational results of our search for emission - line galaxies ( elg ) towards nearby voids. in order to find elg, we started a survey using the iiia - j objective prism plates from the hamburg qso survey. the plates are digitized and an automatic procedure was applied to select the candidates. digitized direct plates were used to determine coordinates and to reject overlaps between spectra. a total area of 1248 square degrees was scanned, distributed in four different regions. all the selected objects were observed with follow - up spectroscopy. we have obtained a final sample of 203 objects, of which 196 are emission - line galaxies, four are galaxies with absorption lines and three are qsos. almost half of our objects are newly discovered ones and three quarters of the given redshifts are new. our sample contains mainly high ionization galaxies and is less sensitive in the detection of low - ionization objects. the apparent magnitudes, as derived from the objective prism plates, range between 15. 0 < b < 19. 5. the sample is dominated by nearby galaxies, with a peak in the redshift distribution at cz = 4500 \, km / s.
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arxiv:astro-ph/9510127
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f $, and $ \ bar f \ to \ bar f $ in some non - tangential sense $ \ mathcal h ^ s | _ { \ partial \ omega } $ - almost everywhere. if, in addition, the boundary function is lipschitz with compact support, then both $ f $ and $ \ bar f $ can be constructed so that they are also lipschitz on $ \ bar \ omega $ and converge to the boundary data continuously. the latter results hold without the additional assumption of the pointwise john condition. finally, we give some applications of the constructed extensions in the connection between poisson problems and bvps.
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arxiv:2303.10717
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we have performed finite temperature quantum monte carlo simulations on the t - jz model on the square lattice. an on - site potential, representing the effect of external mechanisms, is used to stabilize a state of straight site - centered stripes. we show in the first place that various results of our simulations can be related to features observed in high - tc superconductors giving validity to our model. in particular, it is shown that only below a certain temperature the spin regions between stripes are in anti - phase corresponding to an " incommensurate " magnetic order. then, we examine the hole - hole correlations concluding that in the presence of this kind of stripes no sign of attraction of holes is seen at the lowest temperatures we can reach. the consequences for several theories regarding the relationship between stripes and superconductivity are discussed.
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arxiv:cond-mat/0108543
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effect of high and low reynolds number is studied on low frequency vibrational modes of a spherical virus embedded in the aqueous medium. we have used an analytical approach based on fluid dynamic and classical lamb theory to calculate the vibrational modes of a virus with material parameters of lysozyme crystal in water. the obvious size effect on the vibrational modes is observed. the estimated damping time which is of the order of picosecond varies with reynolds number and shows a high value for a critical reynolds number. the stationary eigenfrequency regions are observed for every quantum number l and n suggesting the most probable re ranges for acoustic treatment of viruses in order to detect or annihilate the virus using corresponding viruswater configuration.
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arxiv:1712.02126
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in land surveying, the generation of maps was greatly simplified with the introduction of orthophotos and at a later stage with airborne lidar laser scanning systems. while the original purpose of lidar systems was to determine the altitude of ground elevations, newer full wave systems provide additional information that can be used on classifying the type of ground cover and the generation of maps. the lidar resulting point clouds are huge, multidimensional data sets that need to be grouped in classes of ground cover. we propose a genetic algorithm that aids in classifying these data sets and thus make them usable for map generation. a key feature are tailor - made genetic operators and fitness functions for the subject. the algorithm is compared to a traditional k - means clustering.
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arxiv:1401.4848
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