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we derive a thermal effective action for soft fields in the broken phase of the electroweak theory in the limit of a strongly interacting higgs sector. this action is just the proper generalization of the hard thermal loop effective action of a yang - mills theory when there is a higgs mechanism and for a heavy higgs boson. one can obtain from this action the thermal corrections to the masses of the w, z and the photon.
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arxiv:hep-ph/9902444
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audio separation in real - world scenarios, where mixtures contain a variable number of sources, presents significant challenges due to limitations of existing models, such as over - separation, under - separation, and dependence on predefined training sources. we propose opensep, a novel framework that leverages large language models ( llms ) for automated audio separation, eliminating the need for manual intervention and overcoming source limitations. opensep uses textual inversion to generate captions from audio mixtures with off - the - shelf audio captioning models, effectively parsing the sound sources present. it then employs few - shot llm prompting to extract detailed audio properties of each parsed source, facilitating separation in unseen mixtures. additionally, we introduce a multi - level extension of the mix - and - separate training framework to enhance modality alignment by separating single source sounds and mixtures simultaneously. extensive experiments demonstrate opensep ' s superiority in precisely separating new, unseen, and variable sources in challenging mixtures, outperforming sota baseline methods. code is released at https : / / github. com / tanvir - utexas / opensep. git
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arxiv:2409.19270
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we present a field study of snow settling dynamics based on simultaneous measurements of the atmospheric flow field and snow particle trajectories. specifically, a super - large - scale particle image velocimetry ( slpiv ) system using natural snow particles as tracers is deployed to quantify the velocity field and identify vortex structures in a 22 m $ \ times $ 39 m field of view centered 18 m above the ground. simultaneously, we track individual snow particles in a 3 m $ \ times $ 5 m sample area within the slpiv using particle tracking velocimetry ( ptv ). the results reveal the direct linkage among vortex structures in atmospheric turbulence, the spatial distribution of snow particle concentration, and their settling dynamics. in particular, with snow turbulence interaction at near - critical stokes number, the settling velocity enhancement of snow particles is multifold, and larger than what has been observed in previous field studies. slpiv measurements show higher concentration of snow particles preferentially located on the downward side of the vortices identified in the atmospheric flow field. ptv, performed on high resolution images around the reconstructed vortices, confirms the latter trend and provides statistical evidence of the acceleration of snow particles, as they move toward the downward side of vortices. overall, the simultaneous multi - scale particle imaging presented here enables us to directly quantify the salient features of preferential sweeping, supporting it as an underlying mechanism of snow settling enhancement in the atmospheric surface layer.
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arxiv:2109.04662
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controlling the swimming behavior of bacteria is crucial, for example, to prevent contamination of ducts and catheters. we show the bacteria modeled by deformable microswimmers can accumulate in flows through straight microchannels either in their center or on previously unknown attractors near the channel walls. we predict a novel resonance effect for semiflexible microswimmers in flows through wavy microchannels. as a result, microswimmers can be deflected in a controlled manner so that they swim in modulated channels distributed over the channel cross - section rather than localized near the wall or the channel center. thus, depending on the flow amplitude, both upstream orientation of swimmers and their accumulation at the boundaries which can lead to surface rheotaxis are suppressed. our results suggest new strategies for controlling the behavior of live and synthetic swimmers in microchannels.
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arxiv:2203.01240
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we define a ` tree of fusion systems ' and give a sufficient condition for its completion to be saturated. we apply this result to enlarge an arbitrary fusion system by extending the automorphism groups of certain of its subgroups.
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arxiv:1211.6700
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we present results from lattice simulations of a monolayer graphene model at non - zero temperature. at low temperatures for sufficiently strong coupling the model develops an excitonic condensate of particle - hole pairs corresponding to an insulating phase. the berezinskii - kosterlitz - thouless phase transition temperature is associated with the value of the coupling where the critical exponent delta governing the response of the order parameter at criticality to an external source has a value close to 15. the critical coupling on a lattice with temporal extent n _ t = 32 ( t = 1 / ( n _ t a _ t ) where a _ t is the temporal lattice spacing ) and spatial extent n _ s = 64 is very close to infinite coupling. the value of the transition temperature normalized with the zero temperature fermion mass gap delta _ 0 is given by t _ bkt / delta _ 0 = 0. 055 ( 2 ). this value provides an upper bound on the transition temperature, because simulations closer to the continuum limit where the full u ( 4 ) symmetry is restored may result in an even lower value. in addition, we measured the helicity modulus upsilon and the fermion thermal mass delta _ t ( t ), the later providing evidence for a pseudogap phase with delta _ t > 0 extending to arbitrarily high t.
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arxiv:1105.1043
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some theoretical and experimental aspects regarding the direct dark matter field are mentioned. in particular some arguments, which play a relevant role in the evaluation of model dependent interpretations of experimental results and in comparisons, are shortly addressed.
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arxiv:1201.4582
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this paper develops the tools of formal algebraic geometry in the setting of noncommutative manifolds, roughly ringed spaces locally modeled on the free associative algebra. we define a notion of noncommutative coordinate system, which is a principal bundle for an appropriate group of local coordinate changes. these bundles are shown to carry a natural flat connection with properties analogous to the classical gelfand - kazhdan structure. every noncommutative manifold has an underlying smooth variety given by abelianization. a basic question is existence and uniqueness of noncommutative thickenings of a smooth variety, i. e., finding noncommutative manifolds abelianizing to a given smooth variety. we obtain new results in this direction by showing that noncommutative coordinate systems always arise as reductions of structure group of the commutative bundle of coordinate systems on the underlying smooth variety ; this also explains a relationship between $ \ mathcal { d } $ - modules on the commutative variety and sheaves of modules for the noncommutative structure sheaf.
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arxiv:1408.0830
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the metric dimension of a graph $ g $ is the size of a smallest subset $ l \ subseteq v ( g ) $ such that for any $ x, y \ in v ( g ) $ with $ x \ not = y $ there is a $ z \ in l $ such that the graph distance between $ x $ and $ z $ differs from the graph distance between $ y $ and $ z $. even though this notion has been part of the literature for almost 40 years, prior to our work the computational complexity of determining the metric dimension of a graph was still very unclear. in this paper, we show tight complexity boundaries for the metric dimension problem. we achieve this by giving two complementary results. first, we show that the metric dimension problem on planar graphs of maximum degree $ 6 $ is np - complete. then, we give a polynomial - time algorithm for determining the metric dimension of outerplanar graphs.
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arxiv:1107.2256
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amenable category is a variant of the lusternik - schnirelman category, based on covers by amenable open subsets. we study the monotonicity problem for degree - one maps and amenable category and the relation between amenable category and topological complexity.
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arxiv:2012.00612
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we consider the gross - pitaevskii equation describing an attractive bose gas trapped to a quasi 2d layer by means of a purely harmonic potential, and which rotates at a fixed speed of rotation $ \ omega $. first we study the behavior of the ground state when the coupling constant approaches $ a \ _ * $, the critical strength of the cubic nonlinearity for the focusing nonlinear schr { \ " o } dinger equation. we prove that blow - up always happens at the center of the trap, with the blow - up profile given by the gagliardo - nirenberg solution. in particular, the blow - up scenario is independent of $ \ omega $, to leading order. this generalizes results obtained by guo and seiringer ( lett. math. phys., 2014, vol. 104, p. 141 - - 156 ) in the non - rotating case. in a second part we consider the many - particle hamiltonian for $ n $ bosons, interacting with a potential rescaled in the mean - field manner $ - - a \ _ n n ^ { 2 \ beta - - 1 } w ( n ^ { \ beta } x ), with $ w $ a positive function such that $ \ int \ _ { \ mathbb { r } ^ 2 } w ( x ) dx = 1 $. assuming that $ \ beta < 1 / 2 $ and that $ a \ _ n \ to a \ _ * $ sufficiently slowly, we prove that the many - body system is fully condensed on the gross - pitaevskii ground state in the limit $ n \ to \ infty $.
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arxiv:1802.01854
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we consider the processes $ g \ to w { + } \, q ' $ and $ q \ to z { + } \, q $ and derive the respective splitting functions as functions of two kinematic variables : the longitudinal momentum fraction $ z $ and transverse momentum $ p _ t $ of the produced bosons with respect to the parent quark. we take into account kinematic ( phase space ) restrictions connected with nonzero masses of the gauge bosons and with limited initial energy. we separately consider three different polarization states of the bosons.
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arxiv:2404.10832
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quasi two - body decays b ^ 0 ( t ) - > a _ 1 ^ { + - } ( 1260 ) pi ^ { - + } identified by four charged pions determine a phase alpha _ eff, which is equal to the weak phase alpha in the limit of vanishing penguin amplitudes. applying flavor su ( 3 ) to these decays and to b - > a _ 1 k and b - > k _ 1 pi, with k _ 1 an admixture of k _ 1 ( 1270 ) and k _ 1 ( 1400 ), we derive expressions providing bounds on alpha - alpha _ { eff }. higher precision in alpha may be achieved by an overall fit to a complete set of su ( 3 ) related measurements. a method is sketched applying isospin symmetry to time - dependent invariant mass distributions in b - > pi ^ + pi ^ - pi ^ 0 pi ^ 0.
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arxiv:hep-ph/0512148
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we propose a general approach for differentially private synthetic data generation, that consists of three steps : ( 1 ) select a collection of low - dimensional marginals, ( 2 ) measure those marginals with a noise addition mechanism, and ( 3 ) generate synthetic data that preserves the measured marginals well. central to this approach is private - pgm, a post - processing method that is used to estimate a high - dimensional data distribution from noisy measurements of its marginals. we present two mechanisms, nist - mst and mst, that are instances of this general approach. nist - mst was the winning mechanism in the 2018 nist differential privacy synthetic data competition, and mst is a new mechanism that can work in more general settings, while still performing comparably to nist - mst. we believe our general approach should be of broad interest, and can be adopted in future mechanisms for synthetic data generation.
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arxiv:2108.04978
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the control flow graph ( cfg ) representation of a procedure used by virtually all flow - sensitive program analyses, admits a large number of infeasible control flow paths i. e., these paths do not occur in any execution of the program. hence the information reaching along infeasible paths in an analysis is spurious. this affects the precision of the conventional maximum fixed point ( mfp ) solution of the data flow analysis, because it includes the information reaching along all control flow paths. the existing approaches for removing this imprecision are either specific to a data flow problem with no straightforward generalization or involve control flow graph restructuring which may exponentially blow up the size of the cfg. we lift the notion of mfp solution to define the notion of feasible path mfp ( fpmfp ) solutions that exclude the data flowing along known infeasible paths. the notion of fpmfp is generic and does not involve cfg restructuring. instead, it takes externally supplied information about infeasible paths and lifts any data flow analysis to an analysis that maintains the distinctions between different paths where these distinctions are beneficial, and ignores them where they are not. thus it gets the benefit of a path - sensitive analysis where it is useful without performing a conventional path - sensitive analysis. we evaluated the proposed feasible path mfp solutions for reaching definitions analysis and potentially uninitialized variable analysis on 30 benchmarks. the evaluation results indicate that precision improvement in these two analyses respectively reduce the number def - use pairs by up to 13. 6 % ( average 2. 87 %, geometric mean 1. 75 % ), and reduce the potentially uninitialized variable alarms by up to 100 % ( average 18. 5 %, geo. mean 3 % ). we found that the fpmfp computation time was 2. 9x of mfp computation time on average.
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arxiv:2208.12561
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with a wide range of libraries focused on the machine learning market, such as tensorflow, numpy, pandas, keras, and others, python has made a name for itself as one of the main programming languages. in february 2021, jos \ ' e valim and sean moriarity published the first version of the numerical elixir ( nx ) library, a library for tensor operations written in elixir. nx aims to allow the language be a good choice for gpu - intensive operations. this work aims to compare the results of python and elixir on training convolutional neural networks ( cnn ) using mnist and cifar - 10 datasets, concluding that python achieved overall better results, and that elixir is already a viable alternative.
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arxiv:2210.13945
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we propose a sequence labeling framework with a secondary training objective, learning to predict surrounding words for every word in the dataset. this language modeling objective incentivises the system to learn general - purpose patterns of semantic and syntactic composition, which are also useful for improving accuracy on different sequence labeling tasks. the architecture was evaluated on a range of datasets, covering the tasks of error detection in learner texts, named entity recognition, chunking and pos - tagging. the novel language modeling objective provided consistent performance improvements on every benchmark, without requiring any additional annotated or unannotated data.
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arxiv:1704.07156
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we studied the effects of multiband electronic structure on the thermoelectric and electrical transport properties in the normal state of kagome superconductors $ a $ v $ _ 3 $ sb $ _ 5 $ ( $ a $ = k, rb, cs ). in all three members, the multiband nature is manifested by sign changes in the temperature dependence of the seebeck and hall resistivity, together with sublinear response of the isothermal nernst and hall effects to external magnetic fields in the charge ordered state. moreover, ambipolar transport effects appear ubiquitously in all three systems, giving rise to sizable nernst signal. finally, possible origins of the sign reversal in the temperature dependence of the hall effect are discussed.
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arxiv:2209.01089
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this work investigates the task of unsupervised model personalization, adapted to continually evolving, unlabeled local user images. we consider the practical scenario where a high capacity server interacts with a myriad of resource - limited edge devices, imposing strong requirements on scalability and local data privacy. we aim to address this challenge within the continual learning paradigm and provide a novel dual user - adaptation framework ( dua ) to explore the problem. this framework flexibly disentangles user - adaptation into model personalization on the server and local data regularization on the user device, with desirable properties regarding scalability and privacy constraints. first, on the server, we introduce incremental learning of task - specific expert models, subsequently aggregated using a concealed unsupervised user prior. aggregation avoids retraining, whereas the user prior conceals sensitive raw user data, and grants unsupervised adaptation. second, local user - adaptation incorporates a domain adaptation point of view, adapting regularizing batch normalization parameters to the user data. we explore various empirical user configurations with different priors in categories and a tenfold of transforms for mit indoor scene recognition, and classify numbers in a combined mnist and svhn setup. extensive experiments yield promising results for data - driven local adaptation and elicit user priors for server adaptation to depend on the model rather than user data. hence, although user - adaptation remains a challenging open problem, the dua framework formalizes a principled foundation for personalizing both on server and user device, while maintaining privacy and scalability.
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arxiv:2003.13296
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correlated sources are present in communication systems where protocols ensure that there is some predetermined information for sources to transmit. here, two correlated sources across a channel with eavesdroppers are investigated, and conditions for perfect secrecy when some channel information and some source data symbols ( the predetermined information ) have been wiretapped are determined. the adversary in this situation has access to more information than if a link is wiretapped only and can thus determine more about a particular source. this scenario caters for an application where the eavesdropper has access to some preexisting information. we provide bounds for the channel and key rates for this scenario. further, we provide a method to reduce the key lengths required for perfect secrecy.
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arxiv:1410.8805
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adler ' s lattice equation has acquired the status of a master equation among 2d discrete integrable systems. in this paper we derive what we believe are the first explicit solutions of this equation. in particular it turns out necessary to establish a non - trivial seed solution from which soliton solutions can subsequently be constructed using the b \ " acklund transformation. as a corollary we find the corresponding solutions of the krichever - novikov equation which is obtained from adler ' s equation in a continuum limit.
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arxiv:nlin/0609044
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hadronization corrections to the thrust and related event shape distributions in the two - jet kinematical region of e + e - annihilation are summarized by nonperturbative shape functions. the moments of shape functions are given by universal matrix elements in qcd, which describe the energy flow in qcd final states. we show how the nonperturbative structure of these matrix elements may be inferred from resummed perturbation theory and lorentz invariance. this analysis suggests the same functional forms for the shape functions as were found in phenomenological studies, and sheds light on the physical significance of the parameters that characterize these functions.
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arxiv:hep-ph/0106308
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a generalization of the semisimplicity concept for polyadic algebraic structures is proposed. if semisimple structures can be presented in block diagonal matrix form ( resulting in the wedderburn decomposition ), a general form of polyadic structures is given by block - shift matrices. we combine these forms to get a general shape of semisimple nonderived polyadic structures ( " double " decomposition of two kinds ). we then introduce the polyadization concept ( a " polyadic constructor " ) according to which one can construct a nonderived polyadic algebraic structure of any arity from a given binary structure. the polyadization of supersymmetric structures is also discussed. the " deformation " by shifts of operations on the direct power of binary structures is defined and used to obtain a nonderived polyadic multiplication. illustrative concrete examples for the new constructions are given.
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arxiv:2208.04695
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in this paper, we propose an ai based approach to trailer generation in the form of short videos for online educational courses. trailers give an overview of the course to the learners and help them make an informed choice about the courses they want to learn. it also helps to generate curiosity and interest among the learners and encourages them to pursue a course. while it is possible to manually generate the trailers, it requires extensive human efforts and skills over a broad spectrum of design, span selection, video editing, domain knowledge, etc., thus making it time - consuming and expensive, especially in an academic setting. the framework we propose in this work is a template based method for video trailer generation, where most of the textual content of the trailer is auto - generated and the trailer video is automatically generated, by leveraging machine learning and natural language processing techniques. the proposed trailer is in the form of a timeline consisting of various fragments created by selecting, para - phrasing or generating content using various proposed techniques. the fragments are further enhanced by adding voice - over text, subtitles, animations, etc., to create a holistic experience. finally, we perform user evaluation with 63 human evaluators for evaluating the trailers generated by our system and the results obtained were encouraging.
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arxiv:2301.03957
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asteroid exploration is a pertinent challenge due to the varying complexity of their dynamical environments, shape and communication delays due to distance. thus, autonomous navigation methods are continually being developed and improved in current research to enable their safe exploration. these methods often involve using horizon - based optical navigation ( opnav ) to determine the spacecraft ' s location, which is reliant on the visibility of the horizon. it is critical to ensure the reliability of this measurement such that the spacecraft may maintain an accurate state estimate throughout its mission. this paper presents an algorithm that generates control maneuvers for spacecraft to follow trajectories that allow continuously usable optical measurements to maintain system observability for safe navigation. this algorithm improves upon existing asteroid navigation capabilities by allowing the safe and robust autonomous targeting of various trajectories and orbits at a wide range of distances within optical measurement range. it is adaptable to different asteroid scenarios. overall, the approach develops an all - encompassing system that simulates the asteroid dynamics, synthetic image generation, edge detection, horizon - based opnav, filtering and observability - enhancing control.
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arxiv:2501.15806
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we use a frequency - dependent electro - optic technique to measure the hole mobility in small molecule organic semiconductors, such as 6, 13 bis ( triisopropylsilylethynyl ) - pentacene. measurements are made on semiconductor films in bottom gate, bottom contact field - effect transistors ( fets. ) because of the buried metal layer effect the maximum response, due to absorption in the charge layer, will be for a dielectric film ~ 1 / 4 of a wavelength ( in the dielectric ) ( e. g. ~ 1 micron thick in the infrared. ) results are presented for fets prepared with both spin - cast polymer and alumina dielectrics prepared by atomic layer deposition. at low frequencies the results are fit to solutions to a non - linear differential equation describing the spatial dependence of flowing charge in the fet channel, which allows us to study multiple crystals forming across one set of drain - source contacts. fets prepared on alumina dielectrics show interesting deviations from the model at high frequencies, possibly due to increased contact impedance.
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arxiv:1212.4708
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we present the most recent set of world averages for d0 - d0bar mixing and cp violation parameters, as obtained by the heavy flavor averaging group from a global fit to various measurements. the values obtained for the mixing parameters when allowing for cp violation are x = ( 0. 98 + 0. 24 - 0. 26 ) % and y = ( 0. 83 + - 0. 16 ) % ; the significance of mixing is 10. 2 sigma. there is no evidence for cp violation at the current level of sensitivity.
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arxiv:0911.1464
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the cherenkov telescope array ( cta ) is the next generation very - high energy gamma - ray air - shower cherenkov observatory. cta will consist of many segmented - mirror telescopes of three different diameters, placed in two arrays, one in the northern hemisphere and one in the south, thus covering the whole sky. the total number of mirror tiles will be of the order of 10000, corresponding to a reflective area of ~ 10 ^ 4 m ^ 2. the institute for astronomy and astrophysics in t \ " ubingen is developing procedures to coat glass - substrate - based mirror tiles, is participating to the cta mirror prototype testing, and is prototyping active mirror control alignment mechanics, electronics and software. we will present the current status of our work and plans for future developments.
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arxiv:1307.5194
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we present an exact solution for a factorizable brane - world spacetime with two extra dimensions and explicit brane sources. the compactification manifold has the topology of a two - sphere, and is stabilized by a bulk cosmological constant and magnetic flux. the geometry of the sphere is locally round except for conical singularities at the locations of two antipodal branes, deforming the sphere into an american - style football. the bulk magnetic flux needs to be fine - tuned to obtain flat geometry on the branes. once this is done, the brane geometry is insensitive to the brane vacuum energy, which only affects the conical deficit angle of the extra dimensions. solutions of this form provide a new arena in which to explore brane - world phenomenology and the effects of extra dimensions on the cosmological constant problem.
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arxiv:hep-th/0302067
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the adiabatic transport properties of u ( 1 ) invariant systems are determined by the dependence of the ground state energy on the twisted boundary condition. we examine a one - dimensional tight - binding model in the presence of a single defect and find that the ground state energy of the model shows a universal dependence on the twist angle that can be fully characterized by the transmission coefficient of the scattering by the defect. we identify resulting pathological behaviors of drude weights in the large system size limit : ( i ) both the linear and nonlinear drude weights depend on the twist angle and ( ii ) the $ n $ - th order drude weight diverges proportionally to the $ ( n - 1 ) $ - th power of the system size. to clarify the physical implication of the divergence, we simulate the real - time dynamics of the tight - binding model under a static electric field and show that the divergence does not necessarily imply the large current. furthermore, we address the relation between our results and the boundary conformal field theory.
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arxiv:2105.11378
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in the present investigation, the novel two - step electrochemical process of room temperature synthesis of hg - 1212 superconducting films has been developed and reported first time. electrochemical parameters were optimized by studying cyclic voltammetry ( cv ), linear sweep voltammetry ( lsv ) and chronoamperometry ( ca ) for the deposition of hg - ba - ca - cu alloy at room temperature. current time transient showed progressive growth with hemispheriodal granules, which were then revealed by scanning electron microscopy ( sem ). stoichiometric electrocrystallization to get hg1ba2ca1cu2o6 + x ( hg - 1212 ) was completed by electrochemically intercalating oxygen species into hg - ba - ca - cu alloy at room temperature. the oxygen content in the samples was varied by varying the electrochemical oxidation period and the changes in the crystal structure, microstructure, and superconducting transition temperature ( tc ) and critical current density ( jc ) were recorded. the films oxidized for 28 min showed tc = 104. 7 k with jc = 1. 437 x 103 a / cm2. the dependence of superconducting parameters on oxygen content is correlated with structure property relations and reported in this paper.
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arxiv:cond-mat/0304566
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we report a comprehensive study of dc susceptibility, specific heat, neutron diffraction, and inelastic neutron scattering measurements on polycrystalline ba3 ( cr1 - xvx ) 2o8 samples, where x = 0, 0. 06, 0. 15, and 0. 53. a jahn - teller structure transition occurs for x = 0, 0. 06, and 0. 15 samples and the transition temperature is reduced upon vanadium substitution from 70 ( 2 ) k at x = 0 to 60 ( 2 ) k at x = 0. 06 and 0. 15. the structure becomes less distorted as x increases and such transition disappears at x = 0. 53. the observed magnetic excitation spectrum indicates that the singlet ground state remains unaltered and spin gap energy \ delta = 1. 3 ( 1 ) mev is identical within the instrument resolution for all x. in addition, the dispersion bandwidth w decreases with increase of x. at x = 0. 53, w is reduced to 1. 4 ( 1 ) mev from 2. 0 ( 1 ) mev at x = 0.
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arxiv:1304.6069
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the center of the milky way galaxy hosts a $ \ sim $ 4 million solar mass black hole ( sgr a $ ^ * $ ) that is currently very quiescent with a luminosity many orders of magnitude below those of active galactic nuclei. reflection of x - rays from sgr a $ ^ * $ by dense gas in the galactic center region offers a means to study its past flaring activity on times scales of hundreds and thousands of years. the shape of the x - ray continuum and the strong fluorescent iron line observed from giant molecular clouds in the vicinity of sgr a $ ^ * $ are consistent with the reflection scenario. if this interpretation is correct, the reflected continuum emission should be polarized. here we report observations of polarized x - ray emission in the direction of the galactic center molecular clouds using the imaging x - ray polarimetry explorer ( ixpe ). we measure a polarization degree of 31 \ % $ \ pm $ 11 \ %, and a polarization angle of $ - $ 48 $ ^ \ circ $ $ \ pm $ 11 $ ^ \ circ $. the polarization angle is consistent with sgr a $ ^ * $ being the primary source of the emission, while the polarization degree implies that some 200 years ago the x - ray luminosity of sgr a $ ^ * $ was briefly comparable to a seyfert galaxy.
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arxiv:2304.06967
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our goal with this survey is to provide an overview of the state of the art deep learning methods for face generation and editing using stylegan. the survey covers the evolution of stylegan, from pggan to stylegan3, and explores relevant topics such as suitable metrics for training, different latent representations, gan inversion to latent spaces of stylegan, face image editing, cross - domain face stylization, face restoration, and even deepfake applications. we aim to provide an entry point into the field for readers that have basic knowledge about the field of deep learning and are looking for an accessible introduction and overview.
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arxiv:2212.09102
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we investigate the reflection of a gaussian beam impinging upon the surface of an epsilon - near - zero ( enz ) medium. in particular, we discuss the occurrence of goos - h \ " anchen and imbert - fedorov shifts. our calculations reveal that spatial shifts are significantly enhanced owing to the enz nature of the medium, and that their value and angular position can be tuned by tuning the plasma frequency of the medium.
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arxiv:1911.08999
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in this paper we relate notions of nonclassicality in the simplest nontrivial scenario ( a prepare and measure scenario composed of four preparations and two binary - outcome tomographically complete measurements ). specifically, we relate the established method developed in [ pusey, pra 98, 022112 ( 2018 ) ] to witness a violation of preparation noncontextuality, that is not suitable in experiments where the operational equivalences to be tested are specified in advance, with an approach based on the notion of bounded ontological distinctness for preparations, defined in [ chaturvedi and saha, quantum 4, 345 ( 2020 ) ]. in our approach, we test bounded ontological distinctness for two particular preparations that are relevant in certain information processing tasks in that they are associated with the even - and odd - parity of the bits to communicate. when there exists an ontological model where this distance is preserved we talk of parity preservation. our main result provides a noise threshold under which violating parity preservation ( and so bounded ontological distinctness ) agrees with the established method for witnessing preparation contextuality in the simplest nontrivial scenario. this is achieved by first relating the violation of parity preservation to the quantification of contextuality in terms of inaccessible information as developed in [ marvian, arxiv : 2003. 05984 ( 2020 ) ], that we also show, given the way we quantify noise, to be more robust in witnessing contextuality than pusey ' s noncontextuality inequality. as an application of our findings, we treat the case of two - bit parity - oblivious multiplexing in the presence of noise. in particular, we provide a condition for which the result establishing preparation contextuality as a resource for the quantum advantage of the protocol in the noiseless case still holds in the noisy case.
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arxiv:2311.13474
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time - domain astrophysics benefits from extreme - latitude sites, which can combine intrinsically extended nighttime with good sky conditions. one such location is the polar environment atmospheric research laboratory ( pearl ), at 80 degrees north latitude, on the northwestern edge of ellesmere island, canada. experience gained deploying seeing monitors there has been incorporated into an automated system called " ukaliq " after the common arctic hare, which is also very well suited to its local environment. even with modest aperture, high photometric reliability may be achieved using simple adaptive optics together with observing strategies that best fit the unique set of advantages available at pearl : excellent image quality maintained during many clear, calm, dark periods of 100 hours or more. a potential multi - year search for gravitational microlensing of quasars with ukaliq helps illustrate this niche in the era of large wide - field survey facilities.
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arxiv:1411.5004
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the sun is an active source of radio emission which is often associated with the acceleration of electrons arising from processes such as solar flares and coronal mass ejections ( cmes ). at low radio frequencies ( < 100 mhz ), numerous solar s bursts ( where s stands for short ) and storms of type iii radio bursts have been observed, that are not directly relates to flares and cmes. here, we expand our understanding on the spectral characteristic of these two different types of radio bursts based on observations from the low frequency array ( lofar ). on 9 july 2013, over 3000 solar s bursts accompanied by over 800 type iii radio bursts were observed over a time period of ~ 8 hours. the characteristics of type iii radio bursts are consistent to previous studies, while s bursts show narrow bandwidths, durations and drift rates of about 1 / 2 the drift rate of type iii bursts. type iii bursts and solar s bursts occur in a region in the corona where plasma emission is the dominant emission mechanism as determined by data constrained density and magnetic field models.
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arxiv:1802.10460
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we consider short range correlations in excited states of the finite xxz and xxx heisenberg spin chains. we conjecture that the known results for the factorized ground state correlations can be applied to the excited states too, if the so - called physical part of the construction is changed appropriately. for the ground state we derive simple algebraic expressions for the physical part ; the formulas only use the ground state bethe roots as an input. we conjecture that the same formulas can be applied to the excited states as well, if the exact bethe roots of the excited states are used instead. in the xxz chain the results are expected to be valid for all states ( except certain singular cases where regularization is needed ), whereas in the xxx case they only apply to singlet states or group invariant operators. our conjectures are tested against numerical data from exact diagonalization and coordinate bethe ansatz calculations, and perfect agreement is found in all cases. in the xxx case we also derive a new result for the nearest - neighbour correlator $ \ { \ sigma _ 1 ^ z \ sigma _ 2 ^ z \ } $, which is valid for non - singlet states as well. our results build a bridge between the known theory of factorized correlations, and the recently conjectured tba - like description for the building blocks of the construction.
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arxiv:1605.09347
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assuming that the string inspired, universal sum rules for soft supersymmetry - breaking terms, which have been recently found both in a wide class of four - dimensional superstrings and in supersymmertic gauge - yukawa unified gauge models, are satisfied above and at the grand unification scale, we investigate theirlow energy consequences and derive sum rules in the superpartner spectrum of the minimal supersymmetric standard model.
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arxiv:hep-ph/9710453
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we examine a two - dimensional deep - water surface gravity wave packet generated by a pressure disturbance in the lagrangian reference frame. the pressure disturbance has the form of a narrow - banded weakly nonlinear deep - water wave packet. during forcing, the vorticity equation implies that the momentum resides entirely in the near - surface lagrangian - mean flow, which in this context is often called the ` ` stokes drift ' '. after the forcing turns off, the wave packet propagates away from the forcing region, carrying with it most of the energy imparted by the forcing. these waves together with their induced long wave response have no momentum in a depth integrated sense, in agreement with the classical results of longuet - higgins and stewart ( 1962 ) and mcintyre ( 1981 ). the total flow associated with the propagating packet has no net momentum, in agreement with the classical results. in contrast with the finite - depth scenario discussed by mcintyre ( 1981 ), however, momentum imparted to the fluid during forcing resides in a dipolar structure that persists in the forcing region - - rather than being carried away by shallow water waves. we conclude by examining waves propagating from deep to shallow water and show that wave packets, which initially have no momentum, may have non - zero momentum in finite - depth water through reflected and trapped long waves. this explains how deep water waves acquire momentum as they approach shore. the artificial form of the parameterized forcing from the wind facilitates the thought experiments considered in this paper, as opposed to striving to model more realistic wind forcing scenarios.
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arxiv:2407.11206
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incommensurate heterostructures of two - dimensional ( 2d ) materials, despite their attractive electronic behaviour, are challenging to simulate because of the absence of translation symmetry. experimental investigations of these structures often employ scanning tunneling microscopy ( stm ), however there is to date no comprehensive theory to simulate an stm image in such systems. in this paper, we present a geometry - based method to generate stm images in incommensurate van der waals ( vdw ) heterostructures, which we call the moir \ ' e plane wave expansion model ( mpwem ). we generate the stm images using a weighted sum of three image terms : the non - interacting stm images of ( 1 ) the substrate layer, ( 2 ) the adsorbate layer, and ( 3 ) a semi - empirical fourier expansion of the moir \ ' e wavevectors obtained analytically which results from the interaction of ( 1 ) and ( 2 ). we illustrate and benchmark the model using selected vdw 2d systems composed of structurally and electronically distinct crystals, and show that the method reproduces experimental stm images down to angstrom - scale details. the mpwem, thanks to its simplicity, can serve as an initial prediction tool prior to more computationally expensive calculations which are often limited by the number of atoms and the requirement of periodic supercells, and thus offers a promising class of computationally - friendly stm simulations, of high relevance in the growing field of twistronics.
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arxiv:2310.06535
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there is an interesting dichotomy between a space - time metric considered as external field in a flat background and the same considered as an intrinsic part of the geometry of space - time. we shall describe and compare two other external fields which can be absorbed into an appropriate redefinition of the geometry, this time a noncommutative one. we shall also recall some previous incidences of the same phenomena involving bosonic field theories. it is known that some such theories on the commutative geometry of space - time can be re - expressed as abelian - gauge theory in an appropriate noncommutative geometry. the noncommutative structure can be considered as containing extra modes all of whose dynamics are given by the one abelian action.
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arxiv:hep-th/0009230
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let $ \ mathbb k $ be an algebraically closed field of characteristic zero. let $ v $ be a module over the polynomial ring $ \ mathbb k [ x, y ] $. the actions of $ x $ and $ y $ determine linear operators $ p $ and $ q $ on $ v $ as a vector space over $ \ mathbb k $. define the lie algebra $ l _ v = \ mathbb k \ langle p, q \ rangle \ rightthreetimes v $ as the semidirect product of two abelian lie algebras with the natural action of $ \ mathbb k \ langle p, q \ rangle $ on $ v $. we show that if $ \ mathbb k [ x, y ] $ - modules $ v $ and $ w $ are isomorphic or weakly isomorphic, then the corresponding associated lie algebras $ l _ v $ and $ l _ w $ are isomorphic. the converse is not true : we construct two $ \ mathbb k [ x, y ] $ - modules $ v $ and $ w $ of dimension $ 4 $ that are not weakly isomorphic but their associated lie algebras are isomorphic. we characterize such pairs of $ \ mathbb k [ x, y ] $ - modules of arbitrary dimension. we prove that indecomposable modules $ v $ and $ w $ with $ \ dim v = \ dim w \ geq 7 $ are weakly isomorphic if and only if their associated lie algebras $ l _ v $ and $ l _ w $ are isomorphic.
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arxiv:1701.03750
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we present lofar observations at 150 mhz of the borderline fri / frii giant radio galaxy ngc 6251. this paper presents the most sensitive and highest - resolution images of ngc 6251 at these frequencies to date, revealing for the first time a low - surface - brightness extension to the northern lobe, and a possible backflow associated with the southern lobe. the integrated spectra of components of ngc 6251 are consistent with previous measurements at higher frequencies, similar to results from other lofar studies of nearby radio galaxies. we find the outer structures of ngc 6251 to be either at equipartition or slightly electron dominated, similar to those of frii sources rather than fris ; but this conclusion remains tentative because of uncertainties associated with the geometry and the extrapolation of x - ray measurements to determine the external pressure distribution on the scale of the outer lobes. we place lower limits on the ages of the extension of the northern lobe and the backflow of the southern lobe of $ t \ gtrsim 250 $ myr and $ t \ gtrsim 210 $ myr respectively. we present the first detection of polarisation at 150 mhz in ngc 6251. taking advantage of the high faraday resolution of lofar, we place an upper limit on the magnetic field in the group of $ b < 0. 2 ( \ lambda _ b / 10 { \ rm kpc } ) ^ { - 0. 5 } \ mu $ g for a coherence scale of $ \ lambda _ b < 60 { \ rm kpc } $ and $ b < 13 \ mu $ g for $ \ lambda _ b = 240 $ kpc.
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arxiv:2004.11104
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this paper studies multiclass loss systems with two layers of servers, where each server at the first layer is dedicated to a certain customer class, while the servers at the second layer can handle all customer classes. the routing of customers follows an overflow scheme, where arriving customers are preferentially directed to the first layer. stochastic comparison and coupling techniques are developed for studying how the system is affected by packing of customers, altered service rates, and altered server configurations. this analysis leads to easily computable upper and lower bounds for the performance of the system.
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arxiv:0708.1927
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evolutionary game dynamics of two players with two strategies has been studied in great detail. these games have been used to model many biologically relevant scenarios, ranging from social dilemmas in mammals to microbial diversity. some of these games may in fact take place between a number of individuals and not just between two. here, we address one - shot games with multiple players. as long as we have only two strategies, many results from two player games can be generalized to multiple players. for games with multiple players and more than two strategies, we show that statements derived for pairwise interactions do no longer hold. for two player games with any number of strategies there can be at most one isolated internal equilibrium. for any number of players $ \ boldsymbol { d } $ with any number of strategies n, there can be at most ( d - 1 ) ^ ( n - 1 ) isolated internal equilibria. multiplayer games show a great dynamical complexity that cannot be captured based on pairwise interactions. our results hold for any game and can easily be applied for specific cases, e. g. public goods games or multiplayer stag hunts.
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arxiv:1003.5839
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long - duration ( $ > 2 $ s ) $ \ gamma $ - ray bursts that are believed to originate from the death of massive stars are expected to be accompanied by supernovae. grb 060614, that lasted 102 s, lacks a supernova - like emission down to very stringent limits and its physical origin is still debated. here we report the discovery of near - infrared bump that is significantly above the regular decaying afterglow. this red bump is inconsistent with even the weakest known supernova. however, it can arise from a li - paczy \ ' { n } ski macronova $ - $ the radioactive decay of debris following a compact binary merger. if this interpretation is correct grb 060614 arose from a compact binary merger rather than from the death of a massive star and it was a site of a significant production of heavy r - process elements. the significant ejected mass favors a black hole - neutron star merger but a double neutron star merger cannot be ruled out.
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arxiv:1503.07761
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latent traversal is a popular approach to visualize the disentangled latent representations. given a bunch of variations in a single unit of the latent representation, it is expected that there is a change in a single factor of variation of the data while others are fixed. however, this impressive experimental observation is rarely explicitly encoded in the objective function of learning disentangled representations. this paper defines the variation predictability of latent disentangled representations. given image pairs generated by latent codes varying in a single dimension, this varied dimension could be closely correlated with these image pairs if the representation is well disentangled. within an adversarial generation process, we encourage variation predictability by maximizing the mutual information between latent variations and corresponding image pairs. we further develop an evaluation metric that does not rely on the ground - truth generative factors to measure the disentanglement of latent representations. the proposed variation predictability is a general constraint that is applicable to the vae and gan frameworks for boosting disentanglement of latent representations. experiments show that the proposed variation predictability correlates well with existing ground - truth - required metrics and the proposed algorithm is effective for disentanglement learning.
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arxiv:2007.12885
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we present a detailed x - ray spectral study of the quasar pg 1211 + 143 based on chandra high energy transmission grating spectrometer ( hetgs ) observations collected in a multi - wavelength campaign with uv data using the hubble space telescope cosmic origins spectrograph ( hst - cos ) and radio bands using the jansky very large array ( vla ). we constructed a multi - wavelength ionizing spectral energy distribution using these observations and archival infrared data to create xstar photoionization models specific to the pg 1211 + 143 flux behavior during the epoch of our observations. our analysis of the chandra - hetgs spectra yields complex absorption lines from h - like and he - like ions of ne, mg and si which confirm the presence of an ultra - fast outflow ( ufo ) with a velocity ~ $ - $ 17, 300 km s $ ^ { - 1 } $ ( outflow redshift $ z _ { \ rm out } $ ~ $ - $ 0. 0561 ) in the rest frame of pg 1211 + 143. this absorber is well described by an ionization parameter $ \ log \ xi $ ~ 2. 9 erg s $ ^ { - 1 } $ cm and column density $ \ log n _ { \ rm h } $ ~ 21. 5 cm $ ^ { - 2 } $. this corresponds to a stable region of the absorber ' s thermal stability curve, and furthermore its implied neutral hydrogen column is broadly consistent with a broad ly $ \ alpha $ absorption line at a mean outflow velocity of ~ $ - $ 16, 980 km s $ ^ { - 1 } $ detected by our hst - cos observations. our findings represent the first simultaneous detection of a ufo in both x - ray and uv observations. our vla observations provide evidence for an active jet in pg 1211 + 143, which may be connected to the x - ray and uv outflows ; this possibility can be evaluated using very - long - baseline interferometric ( vlbi ) observations.
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arxiv:1712.07118
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dynamical gauge - higgs unification is presented in higher dimensional gauge theory, in which both adjoint and fundamental higgs fields are a part of gauge fields. dynamical gauge symmetry breaking is induced through the hosotani mechanism. gauge theory, including the u ( 3 ) x u ( 3 ) model, is examined on m ^ 4 x ( t ^ 2 / z _ 2 ).
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arxiv:hep-ph/0409154
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we describe a program to identify optical counterparts to radio sources from the vla first survey using the cambridge apm scans of the poss - i plates. we use radio observations covering 4150 square degrees of the north galactic cap to a 20 cm flux density threshold of 1. 0 mjy ; the 382, 892 sources detected all have positional uncertainties of < 1 " ( radius of 90 % confidence ). our description of the apm catalog, derived from the 148 poss - i o and e plates covering this region, includes an assessment of its astrometric and photometric accuracy, a photometric recalibration using the minnesota aps catalog, a discussion of the classification algorithm, and quantitative tests of the catalog ' s reliability and completeness. we go on to show how the use of first sources as astrometric standards allows us to improve the absolute astrometry of the poss plates by nearly an order of magnitude to ~ 0. 15 " rms. matching the radio and optical catalogs yields counterparts for over 70, 000 radio sources ; we include detailed discussions of the reliability and completeness of these identifications as a function of optical and radio morphology, optical magnitude and color, and radio flux density. an analysis of the problem of radio sources with complex morphologies ( e. g., double - lobed radio galaxies ) is included. we conclude with a brief discussion of the source classes represented among the radio sources with identified counterparts.
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arxiv:astro-ph/0110437
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sparsely annotated semantic segmentation ( sass ) aims to train a segmentation network with coarse - grained ( i. e., point -, scribble -, and block - wise ) supervisions, where only a small proportion of pixels are labeled in each image. in this paper, we propose a novel tree energy loss for sass by providing semantic guidance for unlabeled pixels. the tree energy loss represents images as minimum spanning trees to model both low - level and high - level pair - wise affinities. by sequentially applying these affinities to the network prediction, soft pseudo labels for unlabeled pixels are generated in a coarse - to - fine manner, achieving dynamic online self - training. the tree energy loss is effective and easy to be incorporated into existing frameworks by combining it with a traditional segmentation loss. compared with previous sass methods, our method requires no multistage training strategies, alternating optimization procedures, additional supervised data, or time - consuming post - processing while outperforming them in all sass settings. code is available at https : / / github. com / megvii - research / treeenergyloss.
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arxiv:2203.10739
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while the optimization landscape of policy gradient methods has been recently investigated for partially observed linear systems in terms of both static output feedback and dynamical controllers, they only provide convergence guarantees to stationary points. in this paper, we propose a new policy parameterization for partially observed linear systems, using a past input - output trajectory of finite length as feedback. we show that the solution set to the parameterized optimization problem is a matrix space, which is invariant to similarity transformation. by proving a gradient dominance property, we show the global convergence of policy gradient methods. moreover, we observe that the gradient is orthogonal to the solution set, revealing an explicit relation between the resulting solution and the initial policy. finally, we perform simulations to validate our theoretical results.
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arxiv:2211.04051
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we present the relation between the sphaleron energy and the gravitational wave signals from a first order electroweak phase transition. the crucial ingredient is the scaling law between the sphaleron energy at the temperature of the phase transition and that at zero temperature. we estimate the baryon number preservation criterion, and observe that for a sufficiently strong phase transition, it is possible to probe the electroweak sphaleron using measurements of future space - based gravitational wave detectors.
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arxiv:1910.00234
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the topological nature of chern - simons term describing the interaction of a charge with magnetic monopole is manifested in two ways : it changes the plane dynamical geometry of a free particle for the cone dynamical geometry without distorting the free ( geodesic ) character of the motion, and in the limit of zero charge ' s mass it describes a spin system. this observation allows us to interpret the charge - monopole system alternatively as a free particle of fixed spin with translational and spin degrees of freedom interacting via the helicity constraint, or as a symmetric spinning top with dynamical moment of inertia and " isospin " u ( 1 ) gauge symmetry, or as a system with higher derivatives. the last interpretation is used to get the twistor formulation of the system. we show that the reparametrization and scale invariant monopole chern - simons term supplied with the kinetic term of the same invariance gives rise to the alternative description for the spin, which is related to the charge - monopole system in a spherical geometry. the relationship between the charge - monopole system and ( 2 + 1 ) - dimensional anyon is discussed in the light of the obtained results.
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arxiv:hep-th/0004032
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in material modeling, the calculation speed using the empirical potentials is fast compared to the first principle calculations, but the results are not as accurate as of the first principle calculations. first principle calculations are accurate but slow and very expensive to calculate. in this work, first, the h - h binding energy and h $ _ 2 $ - h $ _ 2 $ interaction energy are calculated using the first principle calculations which can be applied to the tersoff empirical potential. second, the h - h parameters are estimated. after fitting h - h parameters, the mechanical properties are obtained. finally, to integrate both the low - fidelity empirical potential data and the data from the high - fidelity first - principle calculations, the multi - fidelity gaussian process regression is employed to predict the h - h binding energy and the h $ _ 2 $ - h $ _ 2 $ interaction energy. numerical results demonstrate the accuracy of the developed empirical potentials.
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arxiv:2005.08638
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we investigate the sharp asymptotic behavior at criticality of the large fluctuations of extensive observables in renewal models of statistical mechanics, such as the poland - scheraga model of dna denaturation, the fisher - felderhof model of fluids, the wako - sait \ ^ o - mu \ ~ noz - eaton model of protein folding, and the tokar - dreyss \ ' e model of strained epitaxy. these models amount to gibbs changes of measure of a classical renewal process and can be identified with a constrained pinning model of polymers. the extensive observables that enter the thermodynamic description turn out to be cumulative rewards corresponding to deterministic rewards that are uniquely determined by the waiting time and grow no faster than it. the probability decay with the system size of their fluctuations switches from exponential to subexponential at criticality, which is a regime corresponding to a discontinuous pinning - depinning phase transition. we describe such decay by proposing a precise large deviation principle under the assumption that the subexponential correction term to the waiting time distribution is regularly varying. this principle is in particular used to characterize the fluctuations of the number of renewals, which measures the dna - bound monomers in the poland - scheraga model, the particles in the fisher - felderhof model and the tokar - dreyss \ ' e model, and the native peptide bonds in the wako - sait \ ^ o - mu \ ~ noz - eaton model.
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arxiv:2006.09298
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the square of a graph g, denoted g ^ 2, is the graph obtained from g by joining by an edge any two nonadjacent vertices which have a common neighbor. a graph g is said to have the f _ k property if for any set of k distinct vertices { x _ 1, x _ 2,..., x _ k } in g, there is a hamiltonian path from x _ 1 to x _ 2 in g ^ 2 containing k - 2 distinct edges of g of the form x _ iz _ i, i = 3,..., k. it was proved many years ago that every 2 - connected graph has the f _ 3 property. in the first part of this work, we extend this result by proving that every 2 - connected dt - graph has the f _ 4 property ( theorem 2 ) and will show in the second part that this generalization holds for arbitrary 2 - connected graphs, and that there exist 2 - connected graphs which do not have the f _ k property for any natural number k > = 5. altogether, this answers a problem raised before in the affirmative.
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arxiv:1706.04414
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motivated by the results of recent photoemission and tunneling studies, we discuss potential many - body sources of a finite gap in the dirac fermion spectrum of graphene. specifically, we focus on the putative peierls - and cooper - like pairing instabilities which can be driven by sufficiently strong coulomb and electron - phonon interactions, respectively. our results compare favorably with the available experimental and monte carlo data.
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arxiv:0807.0676
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this is an exposition of much of sections vi. 3 and xviii. 3 of " proper and improper forcing ", including preservations for " no random reals over v ", " reals of v form a non - meager set ", " every dense open set contains a dense open set in v ", weak bounding, and weak $ \ omega ^ \ omega $ - bounding. the current version of part i covering sections vi. 1 and vi. 2 is available from the author.
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arxiv:1001.0922
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we present two measurements related to jet production in p + p and central au + au collisions at $ \ sqrt { { s } _ { nn } } $ = 200 gev. firstly, a study of semi - inclusive charged recoil jets coincident with high - $ \ rm { p _ { t } } $ direct - photon and neutral pions, and secondly, the hadron correlations with respect to reconstructed di - jet triggers. indication of medium effects is observed by comparing $ \ gamma $ + jet and $ \ pi ^ { 0 } $ + jet measurements. the di - jet + hadron study shows signs that the medium - induced modifications of an imbalanced set of di - jets with " hard cores " primarily affect the recoil jet.
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arxiv:1704.04814
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a didactical exposition of the classical problem of the trajectory determination of a body, subject to the gravity in a resistant medium, is proposed. our revisitation is aimed at showing a derivation of the problem solution which should be as simple as possible from a technical point of view, in order to be grasped even by first - year undergraduates. a central role in our analysis is played by the so - called " chain rule " for derivatives, which is systematically used to remove the temporal variable from newton ' s law to derive the differential equation of the cartesian representation of the trajectory, with a considerable reduction of the overall mathematical complexity. in particular, for a resistant medium exerting a force quadratic with respect to the velocity our approach leads, in an elementary way, to the differential equation of the trajectory, which is subsequently solved by series expansion. a comparison of the polynomial approximants obtained by truncating such series with the solution recently proposed through a homotopy analysis is also presented.
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arxiv:1211.0840
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feature matching is a challenging computer vision task that involves finding correspondences between two images of a 3d scene. in this paper we consider the dense approach instead of the more common sparse paradigm, thus striving to find all correspondences. perhaps counter - intuitively, dense methods have previously shown inferior performance to their sparse and semi - sparse counterparts for estimation of two - view geometry. this changes with our novel dense method, which outperforms both dense and sparse methods on geometry estimation. the novelty is threefold : first, we propose a kernel regression global matcher. secondly, we propose warp refinement through stacked feature maps and depthwise convolution kernels. thirdly, we propose learning dense confidence through consistent depth and a balanced sampling approach for dense confidence maps. through extensive experiments we confirm that our proposed dense method, \ textbf { d } ense \ textbf { k } ernelized feature \ textbf { m } atching, sets a new state - of - the - art on multiple geometry estimation benchmarks. in particular, we achieve an improvement on megadepth - 1500 of + 4. 9 and + 8. 9 auc $ @ 5 ^ { \ circ } $ compared to the best previous sparse method and dense method respectively. our code is provided at https : / / github. com / parskatt / dkm
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arxiv:2202.00667
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using first - principles approaches we investigate local heating and the inelastic contribution to the current for various alkanethiols sandwiched between metal electrodes. in the absence of good heat dissipation into the bulk electrodes, we find that the local temperature of the alkanethiols is relatively insensitive to their length. this is due to the rates of heating and cooling processes scaling similarly with length. on the other hand, when considering heat dissipation into the bulk electrodes, the local temperature of alkanethiols decreases as their length increases. we also find that the inelastic scattering profile displays an odd - even effect with length which compares well with experimental results. this effect is due to the alternating direction of the ch3 group motion with respect to current flow with increasing c atoms in the chain, and is very sensitive to the structure of the carbon - sulfur - gold bond. inelastic scattering profiles can therefore help illuminate the bonding configuration of molecules to metallic surfaces.
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arxiv:cond-mat/0412511
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we present the sins survey with sinfoni of high redshift galaxies. with 80 objects observed and 63 detected, sins is the largest survey of spatially resolved gas kinematics, morphologies, and physical properties of star - forming galaxies at z ~ 1 - 3. we describe the selection of the targets, the observations, and the data reduction. we then focus on the " sins halpha sample " of 62 rest - uv / optically - selected sources at 1. 3 < z < 2. 6 for which we targeted primarily the halpha and [ nii ] emission lines. only 30 % of this sample had previous near - ir spectroscopic observations. as a whole, the sins halpha sample covers a reasonable representation of massive log ( m * / msun ) > ~ 10 star - forming galaxies at z ~ 1. 5 - 2. 5, with some bias towards bluer systems compared to pure k - selected samples due to the requirement of secure optical redshift. the sample spans two orders of magnitude in stellar mass and in absolute and specific star formation rates, with median values of approximately log ( m * / msun ) = 10. 5, 70 msun / yr, and 3 / gyr. the ionized gas distribution and kinematics are spatially resolved on scales ranging from 1. 5 kpc for adaptive optics assisted observations to typically 4 - 5 kpc for seeing - limited data. the halpha morphologies tend to be irregular and / or clumpy. about one - third are rotation - dominated yet turbulent disks, another third comprises compact and velocity dispersion - dominated objects, and the remaining galaxies are clear interacting / merging systems ; the fraction of rotation - dominated systems increases among the more massive part of the sample. the halpha luminosities and equivalent widths suggest on average roughly twice higher dust attenuation towards the hii regions relative to the bulk of the stars, and comparable current and past - averaged star formation rates. [ abridged ]
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arxiv:0903.1872
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the topological characteristics of bi and its alloys with sb have fueled intense debate since the prediction of three - dimensional topological insulators. however, a definitive resolution has not been reached to date. here, we provide theoretical evidence that surface relaxation conceals the underlying bulk topology of pure bi. using density functional theory calculations for thin bi ( 111 ) films ( up to 17 bilayers ), we first demonstrate a substantial inter - bilayer expansion near the surface. motivated by this finding, we extend our analysis to thick bi ( 111 ) films ( up to 250 bilayers ) incorporating relaxation layers, within the framework of a relativistic empirical tight - binding model. our results reveal that these relaxation layers topologically block the emergence of surface state and significantly suppress the one - particle spectrum of surface states, thereby obscuring the experimental identification of bi ' s topological properties. this phenomenon, which we term " topological blocking ", provides crucial insights into the long - standing difficulty of observing surface states of bi ( 111 ) at the $ \ bar { m } $ point. furthermore, it establishes a framework for understanding and predicting the topological behavior in systems where surface relaxation disrupts the bulk - edge correspondence.
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arxiv:2503.16819
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we have reconstructed the three - dimensional density fluctuation maps to z ~ 1. 5 using the distribution of galaxies observed in the vvds - deep survey. we use this overdensity field to measure the evolution of the probability distribution function and its lower - order moments over the redshift interval 0. 7 < z < 1. 5. we apply a self - consistent reconstruction scheme which includes a complete non - linear description of galaxy biasing and which has been throughly tested on realistic mock samples. we find that the variance and skewness of the galaxy distribution evolve over this redshift interval in a way that is remarkably consistent with predictions of first - and second - order perturbation theory. this finding confirms the standard gravitational instability paradigm over nearly 9 gyrs of cosmic time and demonstrates the importance of accounting for the non - linear component of galaxy biasing to consistently reproduce the higher - order moments of the galaxy distribution and their evolution.
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arxiv:0802.1838
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the use of oxide glasses is pervasive throughout everyday amenities and commodities. such glasses are typically electrical insulators, and endowing them with electrical conductivity without changing their salutary mechanical properties, weight, or thermoformability enables new applications in multifunctional utensils, smart windows, and automotive parts. previous strategies to impart electrical conductivity include modifying the glass composition or forming a solid - in - solid composite of the glass and a conductive phase. here we demonstrate using the latter strategy the highest reported room - temperature electrical conductivity in a bulk oxide glass 1800 s / m corresponding to the theoretical limit for the loading fraction of the conductive phase. this is achieved through glass - sintering of a mixture of carbon nanofibers and oxide flint f2 or soda lime glasses, with the bulk conductivity further enhanced by a polyethylene - block - poly ( ethylene glycol ) additive. a theoretical model provides predictions that are in excellent agreement with the dependence of conductivity of these composites on the carbon - loading fraction. moreover, nanoscale electrical characterization of the composite samples provides evidence for the existence of a connected network of carbon nanofibers throughout the bulk. our results establish a potentially low - cost approach for producing large volumes of highly conductive glass independently of the glass composition.
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arxiv:1911.05273
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we consider variational ( density functional ) models of fluids confined in parallel - plate geometries ( with walls situated in the planes z = 0 and z = l respectively ) and focus on the structure of the pair correlation function g ( r _ 1, r _ 2 ). we show that for local variational models there exist two non - trivial identities relating both the transverse fourier transform g ( z _ \ mu, z _ \ nu ; q ) and the zeroth moment g _ 0 ( z _ \ mu, z _ \ nu ) at different positions z _ 1, z _ 2 and z _ 3. these relations form an algebra which severely restricts the possible form of the function g _ 0 ( z _ \ mu, z _ \ nu ). for the common situations in which the equilibrium one - body ( magnetization / number density ) profile m _ 0 ( z ) exhibits an odd or even reflection symmetry in the z = l / 2 plane the algebra simplifies considerably and is used to relate the correlation function to the finite - size excess free - energy \ gamma ( l ). we rederive non - trivial scaling expressions for the finite - size contribution to the free - energy at bulk criticality and for systems where large scale interfacial fluctuations are present. extensions to non - planar geometries are also considered.
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arxiv:cond-mat/9701092
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evolutionary histories for species that cross with one another or exchange genetic material can be represented by leaf - labelled, directed graphs called phylogenetic networks. a major challenge in the burgeoning area of phylogenetic networks is to develop algorithms for building such networks by amalgamating small networks into a single large network. the level of a phylogenetic network is a measure of its deviation from being a tree ; the higher the level of network, the less treelike it becomes. various algorithms have been developed for building level - 1 networks from small networks. however, level - 1 networks may not be able to capture the complexity of some data sets. in this paper, we present a polynomial - time algorithm for constructing a rooted binary level - 2 phylogenetic network from a collection of 3 - leaf networks or trinets. moreover, we prove that the algorithm will correctly reconstruct such a network if it is given all of the trinets in the network as input. the algorithm runs in time $ o ( t \ cdot n + n ^ 4 ) $ with $ t $ the number of input trinets and $ n $ the number of leaves. we also show that there is a fundamental obstruction to constructing level - 3 networks from trinets, and so new approaches will need to be developed for constructing level - 3 and higher level - networks.
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arxiv:2109.11244
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a generalization of the newton - based matrix splitting iteration method ( gnms ) for solving the generalized absolute value equations ( gaves ) is proposed. under mild conditions, the gnms method converges to the unique solution of the gaves. moreover, we can obtain a few weaker convergence conditions for some existing methods. numerical results verify the effectiveness of the proposed method.
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arxiv:2309.09520
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we consider the nonlinear heat equation $ u _ t = \ delta u + | u | ^ \ alpha u $ with $ \ alpha > 0 $, either on $ { \ mathbb r } ^ n $, $ n \ ge 1 $, or on a bounded domain with dirichlet boundary conditions. we prove that in the sobolev subcritical case $ ( n - 2 ) \ alpha < 4 $, for every $ \ mu \ in { \ mathbb r } $, if the initial value $ u _ 0 $ satisfies $ u _ 0 ( x ) = \ mu | x - x _ 0 | ^ { - \ frac { 2 } { \ alpha } } $ in a neighborhood of some $ x _ 0 \ in \ omega $ and is bounded outside that neighborhood, then there exist infinitely many solutions of the heat equation with the initial condition $ u ( 0 ) = u _ 0 $. the proof uses a fixed - point argument to construct perturbations of self - similar solutions with initial value $ \ mu | x - x _ 0 | ^ { - \ frac { 2 } { \ alpha } } $ on $ { \ mathbb r } ^ n $. moreover, if $ \ mu \ ge \ mu _ 0 $ for a certain $ \ mu _ 0 ( n, \ alpha ) \ ge 0 $, and $ u _ 0 i \ ge 0 $, then there is no nonnegative local solution of the heat equation with the initial condition $ u ( 0 ) = u _ 0 $, but there are infinitely many sign - changing solutions.
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arxiv:1805.04466
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recently, the self - modulation scheme of a weakly pre - bunched electron beam has been proposed [ yan et al., physical review letters 126, 084801 ( 2021 ) ], which is of great promise for high - repetition - rate seeded free - electron lasers ( fels ), such as high - gain harmonic generation ( hghg ). in this paper, the self - modulation scheme is systematically analyzed and optimized, and further experiments in which the self - modulator is resonant at the second harmonic of the seed laser are conducted. the three - dimensional numerical simulations show that the required seed laser intensity in the self - modulation scheme is around three orders of magnitude lower than that of the standard hghg through the optimization of the beam size or the peak current. more importantly, by reasonably setting the initial energy modulation and the resonance of the self - modulator, a more prominent bunching factor and lase at the 30th harmonic of the seed laser can be achieved in a single - stage hghg. moreover, the experiment results confirm that varying the resonance conditions of the self - modulator can still amplify the laser - induced energy modulation, where coherent radiation generated even at the 12th harmonic can be observed. these results indicate that the self - modulation scheme can remarkably reduce the requirements of the seed laser system while improving the harmonic up - conversion efficiency, which paves the way for realizing high - repetition - rate and fully coherent soft x - ray fels.
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arxiv:2206.02195
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a category used by de paiva to model linear logic also occurs in vojtas ' s analysis of cardinal characteristics of the continuum. its morphisms have been used in describing reductions between search problems in complexity theory. we describe this category and how it arises in these various contexts. we also show how these contexts suggest certain new multiplicative connectives for linear logic. perhaps the most interesting of these is a sequential composition suggested by the set - theoretic application.
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arxiv:math/9309208
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a planar boundary introduced \ ` a la symanzik in the 5d topological bf theory, with the only requirement of locality and power counting, allows to uniquely determine a gauge invariant, non topological 4d lagrangian. the boundary condition on the bulk fields is interpreted as a duality relation for the boundary fields, in analogy with the fermionization duality which holds in the 3d case. this suggests that the 4d degrees of freedom might be fermionic, although starting from a bosonic bulk theory. the method we propose to dimensionally reduce a quantum field theory and to identify the resulting degrees of freedom can be applied to a generic spacetime dimension.
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arxiv:1301.3688
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we investigate the vacuum polarization effects associated with a charged massless spin - 1 / 2 field in a higher - dimensional space - time, induced by a composite topological defect. the defect is constituted by a global monopole living on a three - brane and two - dimensional conical space transverse to the latter. in addition, we assume the presence of an extra magnetic flux along the core of the conical space. the heat kernel and the feynman green function are presented in the form of a sum of two terms. the first one corresponds to the contribution coming from the bulk with global monopole in the absence of conical structure of the orthogonal two - space, and the second one is induced by this structure and the magnetic flux. we explicitly evaluate the part in the vacuum expectation value of the energy - momentum tensor induced by the flux carrying conical structure. as in pure cosmic string geometries, only the fractional part of the ratio of the magnetic flux to flux quantum leads to non - trivial effects. the vacuum energy - momentum tensor is an even function of this parameter. we show that for strong gravitational fields corresponding to large values of the solid angle deficit, the effects induced by the conical structure and flux are exponentially suppressed.
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arxiv:0806.1944
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a series of electronic and structural transitions are predicted in molten lithium from first principles. a new phase with tetrahedral local order characteristic of $ sp ^ 3 $ bonded materials and poor electrical conductivity is found at pressures above 150 gpa and temperatures as high as 1000 k. despite the lack of covalent bonding, weakly bound tetrahedral clusters with finite lifetimes are predicted to exist. the stabilization of this phase in lithium involves a unique mechanism of strong electron localization in interstitial regions and interactions among core electrons. the calculations provide evidence for anomalous melting above 20 gpa, with a melting temperature decreasing below 300 k, and point towards the existence of novel low - symmetry crystalline phases.
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arxiv:0805.2781
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visible light communication ( vlc ) using light emitting diodes ( leds ) has been gaining increasing attention in recent years as it is appealing for a wide range of applications such as indoor positioning. orthogonal frequency division multiplexing ( ofdm ) has been applied to indoor wireless optical communications in order to mitigate the effect of multipath distortion of the optical channel as well as increasing data rate. in this paper, a novel ofdm vlc system is proposed which can be utilized for both communications and indoor positioning. a positioning algorithm based on power attenuation is used to estimate the receiver coordinates. we further calculate the positioning errors in all the locations of a room and compare them with those using single carrier modulation scheme, i. e., on - off keying ( ook ) modulation. we demonstrate that ofdm positioning system outperforms its conventional counterpart. finally, we investigate the impact of different system parameters on the positioning accuracy of the proposed ofdm vlc system.
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arxiv:1506.07571
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we consider the problem of estimating the state transition matrix of a linear time - invariant ( lti ) system, given access to multiple independent trajectories sampled from the system. several recent papers have conducted a non - asymptotic analysis of this problem, relying crucially on the assumption that the process noise is either gaussian or sub - gaussian, i. e., " light - tailed ". in sharp contrast, we work under a significantly weaker noise model, assuming nothing more than the existence of the fourth moment of the noise distribution. for this setting, we provide the first set of results demonstrating that one can obtain sample - complexity bounds for linear system identification that are nearly of the same order as under sub - gaussian noise. to achieve such results, we develop a novel robust system identification algorithm that relies on constructing multiple weakly - concentrated estimators, and then boosting their performance using suitable tools from high - dimensional robust statistics. interestingly, our analysis reveals how the kurtosis of the noise distribution, a measure of heavy - tailedness, affects the number of trajectories needed to achieve desired estimation error bounds. finally, we show that our algorithm and analysis technique can be easily extended to account for scenarios where an adversary can arbitrarily corrupt a small fraction of the collected trajectory data. our work takes the first steps towards building a robust statistical learning theory for control under non - ideal assumptions on the data - generating process.
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arxiv:2501.00421
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maximum hands - off control is a control that has the minimum l0 norm among all feasible controls. it is known that the maximum hands - off ( or l0 - optimal ) control problem is equivalent to the l1 - optimal control under the assumption of normality. in this article, we analyze the maximum hands - off control for linear time - invariant systems without the normality assumption. for this purpose, we introduce the lp - optimal control with 0 < p < 1, which is a natural relaxation of the l0 problem. by using this, we investigate the existence and the bang - off - bang property ( i. e. the control takes values of 1, 0 and - 1 ) of the maximum hands - off control. we then describe a general relation between the maximum hands - off control and the l1 - optimal control. we also prove the continuity and convexity property of the value function, which plays an important role to prove the stability when the ( finite - horizon ) control is extended to model predictive control.
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arxiv:1511.05757
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it is well known that every finite subgroup of automorphism group of polynomial algebra of rank 2 over the field of zero characteristic is conjugated with a subgroup of linear automorphisms. we prove that it is not true for an arbitrary torsion subgroup. we construct an example of abelian $ p $ - group of automorphism of polynomial algebra of rank 2 over the field of complex numbers, which is not conjugated with a subgroup of linear automorphisms.
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arxiv:1501.02626
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we propose a renormalization process of a two phase wkb solution, which is based on an appropriate surgery of local uniform asymptotic approximations of the wigner transform of the wkb solution. we explain in details how this process provides the correct spatial variation and frequency scales of the wave field on the caustics where wkb method fails. the analysis has been thoroughly presented in the case of a fundamental problem, that is the semiclassical airy equation, which arises from the model problem of acoustic propagation in a layer with linear variation of the sound speed.
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arxiv:1706.02958
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the ieee 802. 11mc standard introduces fine time measurement ( wi - fi ftm ), allowing high - precision synchronization between peers and round - trip time calculation ( wi - fi rtt ) for location estimation - typically with a precision of one to two meters. this has considerable advantages over received signal strength ( rss ) - based trilateration, which is prone to errors due to multipath reflections. we examine different commercial radios which support wi - fi rtt and benchmark wi - fi ftm ranging over different spectrums and bandwidths. importantly, we find that while wi - fi ftm supports localization accuracy to within one to two meters in ideal conditions during outdoor line - of - sight experiments, for indoor environments at short ranges similar accuracy was only achievable on chipsets supporting wi - fi ftm on wider ( vht80 ) channel bandwidths rather than narrower ( ht20 ) channel bandwidths. finally, we explore the security implications of wi - fi ftm and use an on - air sniffer to demonstrate that wi - fi ftm messages are unprotected. we consequently propose a threat model with possible mitigations and directions for further research.
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arxiv:2303.03766
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compared to the existing function - based models in deep generative modeling, the recently proposed diffusion models have achieved outstanding performance with a stochastic - process - based approach. but a long sampling time is required for this approach due to many timesteps for discretization. schr \ " odinger bridge ( sb ) - based models attempt to tackle this problem by training bidirectional stochastic processes between distributions. however, they still have a slow sampling speed compared to generative models such as generative adversarial networks. and due to the training of the bidirectional stochastic processes, they require a relatively long training time. therefore, this study tried to reduce the number of timesteps and training time required and proposed regularization terms to the existing sb models to make the bidirectional stochastic processes consistent and stable with a reduced number of timesteps. each regularization term was integrated into a single term to enable more efficient training in computation time and memory usage. applying this regularized stochastic process to various generation tasks, the desired translations between different distributions were obtained, and accordingly, the possibility of generative modeling based on a stochastic process with faster sampling speed could be confirmed. the code is available at https : / / github. com / kiungsong / rsb.
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arxiv:2208.07131
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we classify the irreducible unitary modules in category o for the rational cherednik algebras of type g ( r, 1, n ) and give explicit combinatorial formulas for their graded characters. more precisely, we produce a combinatorial algorithm determining, for each r - partition of n, the closed semi - linear set of parameters for which the contravariant form on the irreducible representation with the given r - partition as lowest weight is positive definite. we use this algorithm to give a closed form answer for the cherednik algebra of the symmetric group ( recovering a result of etingof - stoica and the author ) and the weyl groups of classical type.
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arxiv:1106.5094
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many important sets of normalized states in a multipartite quantum system of finite dimension d, such as the set s of all separable states, are real semialgebraic sets. we compute dimensions of many such sets in several low - dimensional systems. by using dimension arguments, we show that there exist separable states which are not convex combinations of d or less pure product states. for instance, such states exist in bipartite m x n systems when ( m - 1 ) ( n - 1 ) > 1. this solves an open problem proposed in [ j. mod. opt. 47 ( 2000 ), 377 - 385 ]. we prove that there exist a separable state rho and a pure product state, whose mixture has smaller length than that of rho. we show that any real rho in s, which is invariant under all partial transpose operations, is a convex sum of real pure product states. in the case of the 2 x n system, the number r of product states can be taken to be r = rank ( rho ). we also show that the general multipartite separability problem can be reduced to the case of real states. regarding the separability problem, we propose two conjectures describing s as a semialgebraic set, which may eventually lead to an analytic solution in some low - dimensional systems such as 2 x 4, 3 x 3 and 2 x 2 x 2.
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arxiv:1206.3775
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we provide evidence that the approach of [ ilyashenko 1991 ] to the proof of dulac ' s theorem has a gap. although the asymptotics of [ ilyashenko 1991 ] capture far more than the asymptotics of dulac, we prove that the arguments for why the asymptotics in [ ilyashenko 1991 ] are not themselves oscillatory is insufficient. we give an explicit counterexample and we draw confines to which ilyashenko ' s result may be restricted in order to keep the validity.
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arxiv:2402.12506
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we introduce the computational 2d materials database ( c2db ), which organises a variety of structural, thermodynamic, elastic, electronic, magnetic, and optical properties of around 1500 two - dimensional materials distributed over more than 30 different crystal structures. material properties are systematically calculated by state - of - the art density functional theory and many - body perturbation theory ( g $ _ 0 \! $ w $ \! _ 0 $ and the bethe - salpeter equation for $ \ sim $ 200 materials ) following a semi - automated workflow for maximal consistency and transparency. the c2db is fully open and can be browsed online or downloaded in its entirety. in this paper, we describe the workflow behind the database, present an overview of the properties and materials currently available, and explore trends and correlations in the data. moreover, we identify a large number of new potentially synthesisable 2d materials with interesting properties targeting applications within spintronics, ( opto - ) electronics, and plasmonics. the c2db offers a comprehensive and easily accessible overview of the rapidly expanding family of 2d materials and forms an ideal platform for computational modeling and design of new 2d materials and van der waals heterostructures.
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arxiv:1806.03173
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we apply the modern multiloop methods to the calculation of the total cross sections of electron - positron annihilation to 2 and 3 photons exactly in $ s / m ^ 2 $ with the accuracy $ o ( \ alpha ^ 3 ) $. examining the asymptotics of our results, we find agreement with ref. [ andreassi _ et _ al _ 1962 ] and discover mistakes in the results of refs. [ eidelman & kuraev _ 1978, berends & kleiss _ 1981 ]. this mistake is due to the terms, omitted in differential cross section in refs. \ [ eidelman & kuraev _ 1978, berends & kleiss _ 1981 ], which are peaked in the kinematic region with all three photons being quasi - parallel to the collision axis. after restoring these terms, we find an agreement of the corrected result of ref. [ berends & kleiss _ 1981 ] with our result.
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arxiv:2006.11082
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m87 hosts a 3 - 6 billion solar mass black hole with a remarkable relativistic jet that has been regularly monitored in radio to tev bands. however, hard x - ray emission \ gtrsim 10kev, which would be expected to primarily come from the jet or the accretion flow, had never been detected from its unresolved x - ray core. we report nustar detection up to 40 kev from the the central regions of m87. together with simultaneous chandra observations, we have constrained the dominant hard x - ray emission to be from its unresolved x - ray core, presumably in its quiescent state. the core spectrum is well fitted by a power law with photon index gamma = 2. 11 ( + 0. 15 - 0. 11 ). the measured flux density at 40 kev is consistent with a jet origin, although emission from the advection - dominated accretion flow cannot be completely ruled out. the detected hard x - ray emission is significantly lower than that predicted by synchrotron self - compton models introduced to explain emission above a gev.
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arxiv:1710.05031
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acoustic scene classification ( asc ) aims to identify the type of scene ( environment ) in which a given audio signal is recorded. the log - mel feature and convolutional neural network ( cnn ) have recently become the most popular time - frequency ( tf ) feature representation and classifier in asc. an audio signal recorded in a scene may include various sounds overlapping in time and frequency. the previous study suggests that separately considering the long - duration sounds and short - duration sounds in cnn may improve asc accuracy. this study addresses the problem of the generalization ability of acoustic scene classifiers. in practice, acoustic scene signals ' characteristics may be affected by various factors, such as the choice of recording devices and the change of recording locations. when an established asc system predicts scene classes on audios recorded in unseen scenarios, its accuracy may drop significantly. the long - duration sounds not only contain domain - independent acoustic scene information, but also contain channel information determined by the recording conditions, which is prone to over - fitting. for a more robust asc system, we propose a robust feature learning ( rfl ) framework to train the cnn. the rfl framework down - weights cnn learning specifically on long - duration sounds. the proposed method is to train an auxiliary classifier with only long - duration sound information as input. the auxiliary classifier is trained with an auxiliary loss function that assigns less learning weight to poorly classified examples than the standard cross - entropy loss. the experimental results show that the proposed rfl framework can obtain a more robust acoustic scene classifier towards unseen devices and cities.
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arxiv:2108.05008
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it has been recently shown that the observed baryon number may originate at the electroweak phase transition, provided that the higgs boson and the lightest stop are sufficiently light. in this work, we perform a detailed analysis, including all dominant two - loop finite temperature corrections to the higgs effective potential, as well as the non - trivial effects proceeding from the mixing in the stop sector, to define the region of parameter space for which electroweak baryogenesis can happen. the limits on the stop and higgs masses are obtained by taking into account the experimental bounds on these quantities, as well as those coming from the requirement of avoiding dangerous color breaking minima. we find for the higgs mass $ m _ h \ simlt 105 $ gev, while the stop mass may be close to the present experimental bound and must be smaller than, or of order of, the top quark mass. these results provide a very strong motivation for further non - perturbative analysis of the electroweak phase transition, as well as for the search for higgs and stop particles at the lep and tevatron colliders.
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arxiv:hep-ph/9710401
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in this paper, we show that there are eight distinct forms of the greenberger - horne - zeilinger ( ghz ) argument for the four - qubit cluster state $ | \ phi _ 4 > $ and forty eight distinct forms for the five - qubit cluster state $ | \ phi _ 5 > $ in the case of the one - dimensional lattice. the proof is obtained by regarding the pair qubits as a single object and constructing the new pauli - like operators. the method can be easily extended to the case of the n - qubit system and the associated bell inequalities are also discussed. consequently, we present a complete construction of the ghz theorem for the cluster states of n - qubit in the case of the one - dimensional lattice.
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arxiv:0812.4915
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the web of science ( wos ; previously known as web of knowledge ) is a paid - access platform that provides ( typically via the internet ) access to multiple databases that provide reference and citation data from academic journals, conference proceedings, and other documents in various academic disciplines. until 1997, it was originally produced by the institute for scientific information. it is currently owned by clarivate. web of science currently contains 79 million records in the core collection and 171 million records on the platform. = = history = = a citation index is built on the fact that citations in science serve as linkages between similar research items, and lead to matching or related scientific literature, such as journal articles, conference proceedings, abstracts, etc. in addition, literature that shows the greatest impact in a particular field, or more than one discipline, can be located through a citation index. for example, a paper ' s influence can be determined by linking to all the papers that have cited it. in this way, current trends, patterns, and emerging fields of research can be assessed. eugene garfield, the " father of citation indexing of academic literature ", who launched the science citation index, which in turn led to the web of science, wrote : citations are the formal, explicit linkages between papers that have particular points in common. a citation index is built around these linkages. it lists publications that have been cited and identifies the sources of the citations. anyone conducting a literature search can find from one to dozens of additional papers on a subject just by knowing one that has been cited. and every paper that is found provides a list of new citations with which to continue the search. the simplicity of citation indexing is one of its main strengths. = = = search answer = = = web of science " is a unifying research tool which enables the user to acquire, analyze, and disseminate database information in a timely manner ". this is accomplished because of the creation of a common vocabulary, called ontology, for varied search terms and varied data. moreover, search terms generate related information across categories. acceptable content for web of science is determined by an evaluation and selection process based on the following criteria : impact, influence, timeliness, peer review, and geographic representation. web of science employs various search and analysis capabilities. first, citation indexing is employed, which is enhanced by the capability to search for results across disciplines. the influence, impact, history, and methodology of an idea can be followed from its first instance, notice, or referral to the present
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https://en.wikipedia.org/wiki/Web_of_Science
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artificial intelligence ( ai ) is increasingly utilized in synthesizing visuals, texts, and audio. these ai - based works, often derived from neural networks, are entering the mainstream market, as digital paintings, songs, books, and others. we conceptualize both existing and future human - in - the - loop ( hitl ) approaches for creative applications and to develop more expressive, nuanced, and multimodal models. particularly, how can our expertise as curators and collaborators be encoded in ai models in an interactive manner? we examine and speculate on long term implications for models, interfaces, and machine creativity. our selection, creation, and interpretation of ai art inherently contain our emotional responses, cultures, and contexts. therefore, the proposed hitl may help algorithms to learn creative processes that are much harder to codify or quantify. we envision multimodal hitl processes, where texts, visuals, sounds, and other information are coupled together, with automated analysis of humans and environments. overall, these hitl approaches will increase interaction between human and ai, and thus help the future ai systems to better understand our own creative and emotional processes.
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arxiv:2110.03569
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we present a quantitative and statistical analysis of the molecular gas morphology in 73 nearby galaxies using high spatial resolution co ( $ j $ = 2 - 1 ) data obtained from the atacama large millimeter / submillimeter array ( alma ) by the phangs large program. we applied three model - independent parameters : concentration ( $ c $ ), asymmetry ( $ a $ ), and clumpiness ( $ s $ ) which are commonly used to parameterize the optical and infrared morphology of galaxies. we find a clear apparent correlation between $ a $ and $ s $, with a spearman ' s rank correlation coefficient of $ 0. 52 $ with a $ p $ - value of $ 2 \ times10 ^ { - 6 } $. this suggests a higher abundance of molecular clumps ( i. e. giant molecular cloud associations ) in galaxies that display stronger distortion or biased large - scale molecular gas distribution. in addition, the analysis of the $ c $ parameter suggests high central molecular concentration in most barred spiral galaxies investigated in this study. furthermore, we found a positive correlation between the length of the bar structure ( $ r _ \ mathrm { bar } / r _ { 25 } $ ) and the $ c $ parameter, with a spearman ' s rank correlation coefficient of $ 0. 63 $ with a $ p $ - value of $ 3. 8 \ times 10 ^ { - 5 } $, suggesting that larger bar structure can facilitate overall molecular gas transport and yield higher central concentration than galaxies with shorter bars. finally, we offer a possible classification scheme of nearby disk galaxies which is based on the cas parameters of molecular gas.
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arxiv:2404.01427
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new grids of atlas9 models have been calculated using revised convection parameters and updated opacity - distribution functions, for chemical compositions intended to be representative of solar, [ m / h ] = + 0. 3, + 0. 5, large magellanic cloud ( lmc ), and small magellanic cloud ( smc ) abundances. the grids cover t ( eff ) = 3. 5 - 50kk, from log ( g ) = 5. 0 to the effective eddington limit. limb - darkening coefficients and synthetic photometry are presented in the ubvrijhklm, uvby, ugriz, wfcam, hipparcos / tycho, and kepler passbands for these models, and for castelli ' s comparable ` new - odf ' grids. flux distributions are given for the new models. the sensitivity of limb - darkening coefficients to the adopted physics is illustrated.
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arxiv:1011.2631
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##5 $. detailed comparisons with results from similar related works are given.
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arxiv:1802.02995
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in recent work we have shown how an accurate reduced model can be utilized to perform mesh refinement in random space. that work relied on the explicit knowledge of an accurate reduced model which is used to monitor the transfer of activity from the large to the small scales of the solution. since this is not always available, we present in the current work a framework which shares the merits and basic idea of the previous approach but does not require an explicit knowledge of a reduced model. moreover, the current framework can be applied for refinement in both random and physical space. in this manuscript we focus on the application to random space mesh refinement. we study examples of increasing difficulty ( from ordinary to partial differential equations ) which demonstrate the efficiency and versatility of our approach. we also provide some results from the application of the new framework to physical space mesh refinement.
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arxiv:1509.06663
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