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multimodal video sentiment analysis aims to integrate multiple modal information to analyze the opinions and attitudes of speakers. most previous work focuses on exploring the semantic interactions of intra - and inter - modality. however, these works ignore the reliability of multimodality, i. e., modalities tend to contain noise, semantic ambiguity, missing modalities, etc. in addition, previous multimodal approaches treat different modalities equally, largely ignoring their different contributions. furthermore, existing multimodal sentiment analysis methods directly regress sentiment scores without considering ordinal relationships within sentiment categories, with limited performance. to address the aforementioned problems, we propose a trustworthy multimodal sentiment ordinal network ( tmson ) to improve performance in sentiment analysis. specifically, we first devise a unimodal feature extractor for each modality to obtain modality - specific features. then, an uncertainty distribution estimation network is customized, which estimates the unimodal uncertainty distributions. next, bayesian fusion is performed on the learned unimodal distributions to obtain multimodal distributions for sentiment prediction. finally, an ordinal - aware sentiment space is constructed, where ordinal regression is used to constrain the multimodal distributions. our proposed tmson outperforms baselines on multimodal sentiment analysis tasks, and empirical results demonstrate that tmson is capable of reducing uncertainty to obtain more robust predictions.
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arxiv:2404.08923
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this paper concerns the problem of classifying finite - dimensional real solvable lie algebras whose derived algebras are of codimension 1 or 2. on the one hand, we present an effective method to classify all $ ( n + 1 ) $ - dimensional real solvable lie algebras having 1 - codimensional derived algebras provided that a full classification of $ n $ - dimensional nilpotent lie algebras is given. on the other hand, the problem of classifying all $ ( n + 2 ) $ - dimensional real solvable lie algebras having 2 - codimensional derived algebras is proved to be wild. in this case, we provide a method to classify a subclass of the considered lie algebras which are extended from their derived algebras by a pair of derivations containing at least one inner derivation.
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arxiv:2003.04652
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we investigate nuclear spin - lattice relaxation data in the normal state of optimally doped ybacuo _ 7 by analyzing the contributions to the relaxation rate of the copper, planar oxygen and yttrium along the directions perpendicular to the applied field. in this new picture there is no contrasting temperature dependence of the copper and oxygen relaxation. we use the model of fluctuating fields to express the rates in terms of hyperfine interaction energies and an effective correlation time tau _ eff characterizing the dynamics of the spin fluid. the former contain the effects of the antiferromagnetic static spin correlations, which cause the hyperfine field constants to be added coherently at low temperature and incoherently at high temperature. the degree of coherency is therefore controlled by the spin - spin correlations. the model is used to determine the temperature - dependent correlation lengths. the temperature - dependent effective correlation time is found to be made up of a linear and a constant contribution that can be related to scattering and spin fluctuations of localized moments respectively. the extrapolation of our calculation at higher temperature fits the data also very well at those temperatures. the underdoped compounds ybacuo _ 6. 63 and ybacuo _ 8 are studied in the limit of the data available with some success by modifying the effective correlation time with a gap parameter. the copper data of the lasrcuo series are then discussed in terms of the interplay between the two contributions to tau _ eff.
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arxiv:cond-mat/0502075
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online continual learning ( ocl ) models continuously adapt to nonstationary data streams, usually without task information. these settings are complex and many traditional cl methods fail, while online methods ( mainly replay - based ) suffer from instabilities after the task shift. to address this issue, we formalize replay - based ocl as a second - order online joint optimization with explicit kl - divergence constraints on replay data. we propose online curvature - aware replay ( ocar ) to solve the problem : a method that leverages second - order information of the loss using a k - fac approximation of the fisher information matrix ( fim ) to precondition the gradient. the fim acts as a stabilizer to prevent forgetting while also accelerating the optimization in non - interfering directions. we show how to adapt the estimation of the fim to a continual setting stabilizing second - order optimization for non - iid data, uncovering the role of the tikhonov regularization in the stability - plasticity tradeoff. empirical results show that ocar outperforms state - of - the - art methods in continual metrics achieving higher average accuracy throughout the training process in three different benchmarks.
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arxiv:2502.01866
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we propose several two higgs doublet models with the addition of an abelian gauge group which free the usual framework from flavor changing neutral interactions and explain neutrino masses through the seesaw mechanism. we discuss the kinetic and mass - mixing gripping phenomenology which encompass several constraints coming from atomic parity violation, the muon anomalous magnetic moment, rare meson decays, higgs physics, lep precision data, neutrino - electron scattering, low energy accelerators and lhc probes.
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arxiv:1705.05388
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materials combining topologically non - trivial behavior and superconductivity offer a potential route for quantum computation. however, the set of available materials intrinsically realizing these properties are scarce. recently, surface superconductivity has been reported in ptbi $ _ 2 $ in its trigonal phase and an inherent weyl semimetal phase has been predicted. here, based on scanning tunneling microscopy experiments, we reveal the signature of topological fermi arcs in the normal state patterns of the quasiparticle interference. we show that the scattering between fermi arcs dominates the interference spectra, providing conclusive evidence for the relevance of weyl fermiology for the surface electronic properties of trigonal ptbi $ _ 2 $.
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arxiv:2407.15790
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random walks on bounded degree expander graphs have numerous applications, both in theoretical and practical computational problems. a key property of these walks is that they converge rapidly to their stationary distribution. in this work we { \ em define high order random walks } : these are generalizations of random walks on graphs to high dimensional simplicial complexes, which are the high dimensional analogues of graphs. a simplicial complex of dimension $ d $ has vertices, edges, triangles, pyramids, up to $ d $ - dimensional cells. for any $ 0 \ leq i < d $, a high order random walk on dimension $ i $ moves between neighboring $ i $ - faces ( e. g., edges ) of the complex, where two $ i $ - faces are considered neighbors if they share a common $ ( i + 1 ) $ - face ( e. g., a triangle ). the case of $ i = 0 $ recovers the well studied random walk on graphs. we provide a { \ em local - to - global criterion } on a complex which implies { \ em rapid convergence of all high order random walks } on it. specifically, we prove that if the $ 1 $ - dimensional skeletons of all the links of a complex are spectral expanders, then for { \ em all } $ 0 \ le i < d $ the high order random walk on dimension $ i $ converges rapidly to its stationary distribution. we derive our result through a new notion of high dimensional combinatorial expansion of complexes which we term { \ em colorful expansion }. this notion is a natural generalization of combinatorial expansion of graphs and is strongly related to the convergence rate of the high order random walks. we further show an explicit family of { \ em bounded degree } complexes which satisfy this criterion. specifically, we show that ramanujan complexes meet this criterion, and thus form an explicit family of bounded degree high dimensional simplicial complexes in which all of the high order random walks converge rapidly to their stationary distribution.
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arxiv:1604.02947
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in recent years, the field of document understanding has progressed a lot. a significant part of this progress has been possible thanks to the use of language models pretrained on large amounts of documents. however, pretraining corpora used in the domain of document understanding are single domain, monolingual, or nonpublic. our goal in this paper is to propose an efficient pipeline for creating a big - scale, diverse, multilingual corpus of pdf files from all over the internet using common crawl, as pdf files are the most canonical types of documents as considered in document understanding. we analysed extensively all of the steps of the pipeline and proposed a solution which is a trade - off between data quality and processing time. we also share a ccpdf corpus in a form or an index of pdf files along with a script for downloading them, which produces a collection useful for language model pretraining. the dataset and tools published with this paper offer researchers the opportunity to develop even better multilingual language models.
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arxiv:2304.14953
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spray cooling a hot target is characterized by strong heat flux density and fast change of the temperature of the wall interface. the heat flux density during spray cooling is determined by the instantaneous substrate temperature, which is illustrated by boiling curves. the variation of the heat flux density is especially notable during different thermodynamic regimes : film, transitional and nucleate boiling. in this study transient boiling curves are obtained by measurement of the local and instantaneous heat flux density produced by sprays of variable mass flux, drop diameter and impact velocity. these spray parameters are accurately characterized using a phase doppler instrument and a patternator. the hydrodynamic phenomena of spray impact during various thermodynamic regimes are observed using a high - speed video system. a theoretical model has been developed for heat conduction in the thin expanding thermal boundary layer in the substrate. the theory is able to predict the evolution of the target temperature in time in the film boiling regime. moreover, a remote asymptotic solution for a heat flux density during the fully developed nucleate boiling regime is developed. the theoretical predictions agree very well with the experimental data for a wide range of impact parameters.
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arxiv:1908.02837
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standard cell - free ( cf ) multiple - input - multiple - output ( mmimo ) systems is a promising technology to cover the demands for higher data rates in fifth - generation ( 5g ) networks and beyond. these systems assume a large number of distributed access points ( aps ) using joint coherent transmission to communicate with the users. however, cf mmimo systems present an increasing computational complexity as the number of users increases. scalable cell - free cf ( scf ) systems have been proposed to face this challenge. given that the cost - efficient deployment of such large networks requires low - cost transceivers, which are prone to unavoidable hardware imperfections, realistic evaluations of scf mmimo systems should take them into account before implementation. hence, in this work, we focus on the impact of hardware impairments ( hwis ) on the scf mmimo systems through a general model accounting for both additive and multiplicative impairments. notably, there is no other work in the literature studying the impact of phase noise ( pn ) in the local oscillators ( los ) of cf mmimo systems or in general the impact of any hwis in scf mmimo systems. in particular, we derive upper and lower bounds on the uplink capacity accounting for hwis. moreover, we obtain the optimal hardware - aware ( ha ) partial minimum mean - squared error ( pmmse ) combiner. especially, the lower bound is derived in closed - form using the theory of deterministic equivalents ( des ). among the interesting findings, we observe that separate los ( slos ) outperform a common lo ( clo ), and the additive transmit distortion degrades more the performance than the additive receive distortion.
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arxiv:2108.12642
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reconfigurable intelligent surfaces ( riss ) hold great potential as one of the key technological enablers for beyond - 5g wireless networks, improving localization and communication performance under line - of - sight ( los ) blockage conditions. however, hardware imperfections might cause ris elements to become faulty, a problem referred to as pixel failures, which can constitute a major showstopper especially for localization. in this paper, we investigate the problem of ris - aided localization of a user equipment ( ue ) under los blockage in the presence of ris pixel failures, considering the challenging single - input single - output ( siso ) scenario. we first explore the impact of such failures on accuracy through misspecified cramer - rao bound ( mcrb ) analysis, which reveals severe performance loss with even a small percentage of pixel failures. to remedy this issue, we develop two strategies for joint localization and failure diagnosis ( jlfd ) to detect failing pixels while simultaneously locating the ue with high accuracy. the first strategy relies on l _ 1 - regularization through exploitation of failure sparsity. the second strategy detects the failures one - by - one by solving a multiple hypothesis testing problem at each iteration, successively enhancing localization and diagnosis accuracy. simulation results show significant performance improvements of the proposed jlfd algorithms over the conventional failure - agnostic benchmark, enabling successful recovery of failure - induced performance degradations.
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arxiv:2302.04436
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we prove that any coadjoint orbit with real eigenvalues of a complex semisimple lie group, equipped with the real part of the canonical holomorphic symplectic form, is symplectomorphic to the cotangent bundle of a ( partial ) flag manifold. moreover, we generalize this result to hyperbolic orbits in a real semisimple lie algebra.
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arxiv:0810.3816
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let $ g $ be a simple graph on $ n $ vertices. let $ h $ be either the complete graph $ k _ m $ or the complete bipartite graph $ k _ { r, s } $ on a subset of the vertices in $ g $. we show that $ g $ contains $ h $ as a subgraph if and only if $ \ beta _ { i, \ alpha } ( h ) \ le \ beta _ { i, \ alpha } ( g ) $ for all $ i \ ge 0 $ and $ \ alpha \ in \ mathbb { z } ^ n $. in fact, it suffices to consider only the first syzygy module. in particular, we prove that $ \ beta _ { 1, \ alpha } ( h ) \ le \ beta _ { 1, \ alpha } ( g ) $ for all $ \ alpha \ in \ mathbb { z } ^ n $ if and only if $ g $ contains a subgraph that is isomorphic to either $ h $ or a multipartite graph $ k _ { 2, \ dots, 2, a, b } $.
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arxiv:1510.04463
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employing a largely unbiased variational exact diagonalization technique, we analyze the consequences of longer - ranged electron hopping and electron - phonon interaction on polaron formation in one dimension. having at our disposal the accurate ground state energy and wavefunction, we calculate and discuss various physical quantities, such as the renormalized band structure, effective mass, wave - function renormalization factor, phonon dressing and drude weight, characterizing the properties of the polaronic quasiparticle. we demonstrate that the electron - phonon coupling affects the relative strength of the nearest - neigbor ( nn ) and next - nearest - neigbor ( nnn ) hopping processes in a dynamic way. most notably we observe that the minimum of the polaron band, occurring at a finite momentum for large negative ratio between nn and nnn transfer, jumps to zero momentum as the electron - phonon coupling exceeds a critical one, thereby causing a rather sharp polaron transition in the one - dimensional extended holstein model. the signatures of this transition are seen in the effective mass and polaron mobility, and therefore should be easily detectable by transport measurements.
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arxiv:2311.12677
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we introduce a class of monotone $ \ sigma $ - complete effect algebras, called representable, which are $ \ sigma $ - homomorphic images of a class of monotone $ \ sigma $ - complete effect algebras of functions taking values in the interval $ [ 0, 1 ] $ and with pointwise defined effect algebra operations. we exhibit different types of compatibilities and show their connection to representability. finally, we study observables and show situations when information of an observable on all intervals of the form $ ( - \ infty, t ) $ gives full information about the observable.
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arxiv:1311.3221
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given a motivic spectrum $ k $ over a smooth proper scheme which is dualizable over an open subscheme, we define its quadratic artin conductor under some assumptions, and prove a formula relating the quadratic euler characteristic of $ k $, the rank of $ k $ and the quadratic artin conductor. as a consequence, we obtain a quadratic refinement of the classical grothendieck - ogg - shafarevich formula.
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arxiv:2211.10985
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we present a novel application of partial convolutional neural networks ( pcnn ) that can inpaint masked images of the cosmic microwave background. the network can reconstruct both the maps and the power spectra to a few percent for circular and irregularly shaped masks covering up to ~ 10 % of the image area. by performing a kolmogorov - smirnov test we show that the reconstructed maps and power spectra are indistinguishable from the input maps and power spectra at the 99. 9 % level. moreover, we show that pcnns can inpaint maps with regular and irregular masks to the same accuracy. this should be particularly beneficial to inpaint irregular masks for the cmb that come from astrophysical sources such as galactic foregrounds. the proof of concept application shown in this paper shows that pcnns can be an important tool in data analysis pipelines in cosmology.
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arxiv:2011.01433
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we introduce the so - called bishop - phelps - bollob \ ' as property for positive functionals, a particular case of the bishop - phelps - bollob \ ' as property for positive operators. first we show a version of the bishop - phelps - bollob \ ' as theorem for positive elements and positive functionals in the dual of any banach lattice. we also characterize the strong bishop - phelps - bollob \ ' as property for positive functionals in a banach lattice. we prove that any finite - dimensional banach lattice has the the bishop - phelps - bollob \ ' as property for positive functionals. a sufficient and a necessary condition to have the bishop - phelps - bollob \ ' as property for positive functionals are also provided. as a consequence of this result, we obtain that the spaces $ l _ p ( \ mu ) $ ( $ 1 \ le p < \ infty $ ), for any positive measure $ \ mu, $ $ c ( k ) $ and $ \ mathcal { m } ( k ) $, for any compact and hausdorff topological space $ k, $ satisfy the bishop - phelps - bollob \ ' as property for positive functionals. we also provide some more clarifying examples.
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arxiv:2106.05935
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in this paper, we consider two - dimensional n = ( 4, 4 ) supersymmetric yang - mills ( sym ) theory and deform it by a mass parameter m with keeping all supercharges. we further add another mass parameter m in a manner to respect two of the eight supercharges and put the deformed theory on a two - dimensional square lattice, on which the two supercharges are exactly preserved. the flat directions of scalar fields are stabilized due to the mass deformations, which gives discrete minima representing fuzzy spheres. we show in the perturbation theory that the lattice continuum limit can be taken without any fine tuning. around the trivial minimum, this lattice theory serves as a non - perturbative definition of two - dimensional n = ( 4, 4 ) sym theory. we also discuss that the same lattice theory realizes four - dimensional n = 2 u ( k ) sym on r ^ 2 x ( fuzzy r ^ 2 ) around the minimum of k - coincident fuzzy spheres.
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arxiv:1109.6807
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bioinformatics encompass storing, analyzing and interpreting the biological data. most of the challenges for machine learning methods like cellular automata is to furnish the functional information with the corresponding biological sequences. in eukaryotes dna is divided into introns and exons. the introns will be removed to make the coding region by a process called splicing. by indentifying a splice site we can easily specify the dna sequence category ( donor / accepter / neither ). splicing sites play an important role in understanding the genes. a class of ca which can handle fuzzy logic is employed with modified clonal algorithm is proposed to identify the splicing site. this classifier is tested with irvine primate splice junction database. it is compared with nnspiice, genio, hspl and spiice view. the reported accuracy and efficiency of prediction is quite promising.
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arxiv:1404.6020
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in this work we take a category theoretic perspective on the relationship between probabilistic modeling and function approximation. we begin by defining two extensions of function composition to stochastic process subordination : one based on the co - kleisli category under the comonad ( omega x - ) and one based on the parameterization of a category with a lawvere theory. we show how these extensions relate to the category stoch and other markov categories. next, we apply the para construction to extend stochastic processes to parameterized statistical models and we define a way to compose the likelihood functions of these models. we conclude with a demonstration of how the maximum likelihood estimation procedure defines an identity - on - objects functor from the category of statistical models to the category of learners. code to accompany this paper can be found at https : / / github. com / dshieble / categorical _ stochastic _ processes _ and _ likelihood
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arxiv:2005.04735
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we consider the most general kaluza - klein ( kk ) compactification on $ s ^ 1 / \ mathbb { z } _ 2 $ of a five dimensional ( $ 5d $ ) graviton - dilaton system, with a non - vanishing dilaton background varying linearly along the fifth dimension. we show that this background produces a higgs mechanism for the kk vector coming from the $ 5d $ metric, which becomes massive by absorbing the string frame radion. the $ \ mathcal { n } = 2 $ minimal supersymmetric extension of this model, recently built as the holographic dual of little string theory, is then re - investigated. an analogous mechanism can be considered for the $ 4d $ vector coming from the ( universal ) $ 5d $ kalb - ramond two - form. packaging the two massive vectors into a spin - $ 3 / 2 $ massive multiplet, it is shown that the massless spectrum arranges into a $ \ mathcal { n } = 1 $, $ d = 4 $ supersymmetric theory. this projection is compatible with an orbifold which preserves half of the original supersymmetries already preserved by the background. the description of the partial breaking $ \ mathcal { n } = 2 \ rightarrow \ mathcal { n } = 1 $ in this framework, with only vector multiplets and no hypermultiplets, remains an interesting open question which deserves further investigation.
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arxiv:2106.15184
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thanks to the advent of sensitive and broad bandwidth instrumentation, complex organic molecules ( coms ) have been found in a wide variety of interstellar environments, not only in our galaxy but also in external galaxies up to a redshift of 0. 89. the detection of coms in cold environments such as starless or prestellar cores has challenged our understanding of com formation and new ideas are being implemented in chemical models and explored in laboratory experiments. at the protostellar stage, the advent of new interferometers such as the atacama large millimeter / submillimeter array ( alma ) has allowed the mapping of the weak emission of coms in the protostellar envelopes and protoplanetary disks around both low - mass and high - mass protostars, pinpointing their location and revealing differentiation between the different families of molecules. in this way, thermal and non - thermal desorption mechanisms can be probed, constraining the efficiency of formation of coms in the gas phase versus on grain surfaces. some degree of continuity in the com composition is found from the early to late stages of star formation, suggesting that a significant fraction of coms are formed at the initial conditions of star formation. for extreme environments such as the galactic center, cosmic rays and low - velocity shocks seem to influence the com composition of low and high - density gas components. the spectral confusion limit will be a major challenge for the detection of new coms in future spectroscopic surveys. however, low - frequency interferometers targeting sources with low - excitation temperatures may help to overcome this limit.
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arxiv:2503.17104
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we present a tensor network especially suited for multi - orbital anderson impurity models and as an impurity solver for multi - orbital dynamical mean - field theory ( dmft ). the solver works directly on the real - frequency axis and yields very high spectral resolution at all frequencies. we use a large number $ \ left ( \ mathcal { o } ( 100 ) \ right ) $ of bath sites, and therefore achieve an accurate representation of the bath. the solver can treat full rotationally invariant interactions with reasonable numerical effort. we show the efficiency and accuracy of the method by a benchmark for the testbed material srvo $ _ 3 $. there we observe multiplet structures in the high - energy spectrum which are almost impossible to resolve by other multi - orbital methods. the resulting structure of the hubbard bands can be described as a broadened atomic spectrum with rescaled interaction parameters. additional features emerge when $ u $ is increased. the impurity solver offers a new route to the calculation of precise real - frequency spectral functions of correlated materials.
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arxiv:1612.05587
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microwave detectors based on the spin - transfer torque diode effect are among the key emerging spintronic devices. by utilizing the spin of electrons in addition to charge, they have the potential to overcome the theoretical performance limits of their semiconductor ( schottky ) counterparts, which cannot operate at low input power. here, we demonstrate nanoscale microwave detectors exhibiting record - high detection sensitivity of 75400 mv mw $ ^ { - 1 } $ at room temperature, without any external bias fields, for input microwave power down to 10 nw. this sensitivity is 20x and 6x larger than state - of - the - art schottky diode detectors ( 3800 mv mw $ ^ { - 1 } $ ) and existing spintronic diodes with > 1000 oe magnetic bias ( 12000 mv mw $ ^ { - 1 } $ ), respectively. micromagnetic simulations supported by microwave emission measurements reveal the essential role of the injection locking to achieve this sensitivity performance. the results enable dramatic improvements in the design of low input power microwave detectors, with wide - ranging applications in telecommunications, radars, and smart networks.
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arxiv:1410.4958
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this thesis describes the basic framework and applications of a relativistic ray - tracing code for analyzing accretion processes around kerr black holes. we begin in chapter 1 with a brief historical summary of the major advances in black hole astrophysics over the past few decades. in chapter 2 we present a detailed description of the ray - tracing code, which is used to calculate the transfer function between the accretion disk and the detector. in chapter 3, we employ a simple ` ` hot spot ' ' model to explain the frequencies and amplitudes of quasi - periodic oscillations ( qpos ). in chapter 4, we introduce additional features to the hot spot model to explain the broadening of the qpo peaks as well as the damping of higher - frequency harmonics in the power spectrum. in chapter 5 we present a description of the structure of a relativistic alpha - disk around a kerr black hole, and the observed spectrum from such a disk. the features of this modified thermal spectrum may be used to infer the physical properties of the accretion disk and the central black hole. in chapter 6 we develop a monte carlo code to calculate the detailed propagation of photons from a hot spot emitter scattering through a corona surrounding the black hole. the coronal scattering has two major observable effects : the inverse - compton process alters the photon spectrum by adding a high energy power - law tail, and the random scattering of each photon effectively damps out the highest frequency modulations in the x - ray light curve.
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arxiv:astro-ph/0601406
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let f _ { n + m } be the free group of rank n + m, with generators x _ 1,..., x _ { n + m }. an automorphism \ phi of f _ { n + m } is called partially symmetric if for each 1 \ le i \ le m, \ phi ( x _ i ) is conjugate to x _ j or x _ j ^ { - 1 } for some 1 \ le j \ le m. let \ sigma \ aut _ n ^ m be the group of partially symmetric automorphisms. we prove that for any m \ ge 0 the inclusion \ sigma \ aut _ n ^ m \ to \ sigma \ aut _ { n + 1 } ^ m induces an isomorphism in rational homology for dimensions i satisfying n \ ge ( 3 ( i + 1 ) + m ) / 2, with a similar statement for the groups p \ sigma \ aut _ n ^ m of pure partially symmetric automorphisms. we also prove that for any n \ ge 0 the inclusion \ sigma \ aut _ n ^ m \ to \ sigma \ aut _ n ^ { m + 1 } induces an isomorphism in rational homology for dimensions i satisfying m > ( 3i - 1 ) / 2.
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arxiv:1203.4845
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( abridged ) avocado aims at establishing firm conclusions on the formation and evolution of dwarf galaxies by constructing and analysing a homogeneous, multiwavelength dataset for a statistically significant sample of approximately 6500 nearby dwarfs ( m _ i > - 18 mag ). we present the sample selection criteria and describe the suite of analysis tools, some of them developed in the framework of the virtual observatory. we make use of optical spectra and uv - to - nir imaging of the dwarf sample to derive sfrs, stellar masses, ages and metallicities - which are further supplemented with structural parameters that are used to classify them morphologically. this dataset, coupled with a detailed characterisation of each dwarf ' s environment, allows for a fully comprehensive investigation of their origins and to track the potential evolutionary paths between the different dwarf types. we characterise the local environment of all dwarfs in our sample, paying special attention to trends with current star formation activity. we find that virtually all quiescent dwarfs are located in the vicinity ( projected distances < 1. 5 mpc ) of l * companions, consistent with recent results. while star - forming dwarfs are preferentially found at separations of the order of 1 mpc, there appears to be a tail towards low separations ( < 100 kpc ) in the distribution of projected distances. we speculate that, modulo projection effects, this probably represents a genuine population of late - type dwarfs caught upon first infall about their host and before environmental quenching has fully operated. in this context, these results suggest that internal mechanisms - such as gas exhaustion via star formation or feedback effects - are not sufficient to completely cease the star formation activity in dwarf galaxies, and that becoming the satellite of a massive central galaxy appears to be a necessary condition to create a quiescent dwarf.
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arxiv:1301.5320
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we study the dynamical evolution of globular clusters using our h \ ' enon - type monte carlo code for stellar dynamics including all relevant physics such as two - body relaxation, single and binary stellar evolution, galactic tidal stripping, and strong interactions such as physical collisions and binary mediated scattering. we compute a large database of several hundred models starting from broad ranges of initial conditions guided by observations of young and massive star clusters. we show that these initial conditions very naturally lead to present day clusters with properties including the central density, core radius, half - light radius, half - mass relaxation time, and cluster mass, that match well with those of the old galactic globular clusters. in particular, we can naturally reproduce the bimodal distribution in observed core radii separating the " core - collapsed " vs the " non core - collapsed " clusters. we see that the core - collapsed clusters are those that have reached or are about to reach the equilibrium " binary burning " phase. the non core - collapsed clusters are still undergoing gravo - thermal contraction.
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arxiv:1207.3063
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the influence of turbulent effects on a fluid flow through a ( pseudo ) porous media is studied by numerically solving the set of reynolds - averaged navier - stokes equations with the $ \ kappa $ - $ \ epsilon $ model for turbulence. the spatial domains are two - dimensional rectangular grids with different { \ it porosities } obtained by the random placing of rigid obstacles. the objective of the simulations is to access the behavior of the generalized friction factor with varying reynolds number. a good agreement with the forchheimer ' s equation is observed. the flow distribution at both low and high reynolds conditions is also analyzed.
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arxiv:cond-mat/0102238
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correct risk estimation of policyholders is of great significance to auto insurance companies. while the current tools used in this field have been proven in practice to be quite efficient and beneficial, we argue that there is still a lot of room for development and improvement in the auto insurance risk estimation process. to this end, we develop a framework based on a combination of a neural network together with a dimensionality reduction technique t - sne ( t - distributed stochastic neighbour embedding ). this enables us to visually represent the complex structure of the risk as a two - dimensional surface, while still preserving the properties of the local region in the features space. the obtained results, which are based on real insurance data, reveal a clear contrast between the high and the low risk policy holders, and indeed improve upon the actual risk estimation performed by the insurer. due to the visual accessibility of the portfolio in this approach, we argue that this framework could be advantageous to the auto insurer, both as a main risk prediction tool and as an additional validation stage in other approaches.
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arxiv:2212.09385
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the well - known braess paradox in congestion games states that adding an additional road to a transportation network may increase the total travel time, and consequently decrease the overall efficiency. motivated by this, this paper presents a paradox in a similar spirit emerging from another distributed resource allocation game on networks, namely the power allocation game between countries developed in \ cite { allocation }. the paradox is that by having additional friends may actually decrease a country ' s total welfare in equilibrium. conditions for this paradox to occur as well as some price of anarchy results are also derived.
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arxiv:1802.03669
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superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. we describe a demonstration of an array of dc biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. in this design, each individual nanowire is part of a resonant lc circuit where the inductance is dominated by the kinetic inductance of the nanowire. the circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line which carries the signals to a cryogenic low noise amplifier. all of the nanowires are connected via resistors to a single dc bias line that enables the nanowires to be current biased close to their critical current. when a photon hits a nanowire it creates a normal hot spot which produces a voltage pulse across the lc circuit. this pulse rings down at the resonant frequency of the lc circuit over a time period that is fixed by the quality factor. we present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.
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arxiv:1905.06880
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in this paper we derive a hierarchy of differential equations which uniquely determine the coefficients in the asymptotic expansion, for large $ n $, of the logarithm of the partition function of $ n \ times n $ hermitian random matrices. these coefficients are generating functions for graphical enumeration on riemann surfaces. the case that we particularly consider is for an underlying measure that differs from the gaussian weight by a single monomial term of degree $ 2 \ nu $. the coupling parameter for this term plays the role of the independent dynamical variable in the differential equations. from these equations one may deduce functional analytic characterizations of the coefficients in the asymptotic expansion. moreover, this ode system can be solved recursively to explicitly construct these coefficients as functions of the coupling parameter. this analysis of the fine structure of the asymptotic coefficients can be extended to multiple coupling parameters and we present a limited illustration of this for the case of two parameters.
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arxiv:math-ph/0606010
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we investigate the $ t = 0 $ phase diagram of a variant of the one - dimensional extended hubbard model where particles interact via a finite - range soft - shoulder potential. using density matrix renormalization group ( dmrg ) simulations, we evidence the appearance of cluster luttinger liquid ( cll ) phases, similarly to what first predicted in a hard - core bosonic chain [ m. mattioli, m. dalmonte, w. lechner, and g. pupillo, phys. rev. lett. 111, 165302 ]. as the interaction strength parameters change, we find different types of clusters, that encode the order of the ground state in a semi - classical approximation and give rise to different types of clls. interestingly, we find that the conventional tomonaga luttinger liquid ( tll ) is separated by a critical line with a central charge $ c = 5 / 2 $, along which the two ( spin and charge ) bosonic degrees of freedom ( corresponding to $ c = 1 $ each ) combine in a supersymmetric way with an emergent fermionic excitation ( $ c = 1 / 2 $ ). we also demonstrate that there are no significant spin correlations.
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arxiv:1909.12168
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shape is one of the main features in content based image retrieval ( cbir ). this paper proposes a new shape signature. in this technique, features of each shape are extracted based on four sides of the rectangle that covers the shape. the proposed technique is fourier based and it is invariant to translation, scaling and rotation. the retrieval performance between some commonly used fourier based signatures and the proposed four sides distance ( fsd ) signature has been tested using mpeg - 7 database. experimental results are shown that the fsd signature has better performance compared with those signatures.
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arxiv:1302.5894
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we perform the first simultaneous global qcd analysis of spin - averaged and spin - dependent parton distribution functions ( pdfs ), including single jet production data from unpolarized and polarized hadron collisions. we critically assess the impact of su ( 3 ) flavor symmetry and pdf positivity assumptions on the quark and gluon helicity pdfs, and find strong bias from these, particularly on the gluon polarization. the simultaneous analysis allows for the first time extraction of individual helicity - aligned and antialigned pdfs with a consistent treatment of uncertainties.
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arxiv:2201.02075
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we study the convergence properties of riemannian gradient method for solving the consensus problem ( for an undirected connected graph ) over the stiefel manifold. the stiefel manifold is a non - convex set and the standard notion of averaging in the euclidean space does not work for this problem. we propose distributed riemannian consensus on stiefel manifold ( drcs ) and prove that it enjoys a local linear convergence rate to global consensus. more importantly, this local rate asymptotically scales with the second largest singular value of the communication matrix, which is on par with the well - known rate in the euclidean space. to the best of our knowledge, this is the first work showing the equality of the two rates. the main technical challenges include ( i ) developing a riemannian restricted secant inequality for convergence analysis, and ( ii ) to identify the conditions ( e. g., suitable step - size and initialization ) under which the algorithm always stays in the local region.
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arxiv:2101.09346
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quintessential inflation unifies inflation and late time acceleration by a single scalar field. such a scenario, with canonical and non - canonical scalar fields, has been discussed. the scalar field behaves as an inflaton field during inflation and as a quintessence field during late time. also the predictions of the models has been compared with the recent planck data.
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arxiv:1801.03272
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we derive constraints on the statistics of the charge transfer between two conductors in the model of arbitrary time - dependent instant scattering of non - interacting fermions at zero temperature. the constraints are formulated in terms of analytic properties of the generating function : its zeroes must lie on the negative real axis. this result generalizes existing studies for scattering by a time - independent scatterer under time - dependent bias voltage.
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arxiv:0709.2898
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na61 / shine ( sps heavy ion and neutrino experiment ) is a multi - purpose experimental facility to study hadron production in hadron - proton, hadron - nucleus and nucleus - nucleus collisions at the cern super proton synchrotron. it recorded the first physics data with hadron beams in 2009 and with ion beams ( secondary 7be beams ) in 2011. na61 / shine has greatly profited from the long development of the cern proton and ion sources and the accelerator chain as well as the h2 beamline of the cern north area. the latter has recently been modified to also serve as a fragment separator as needed to produce the be beams for na61 / shine. numerous components of the na61 / shine set - up were inherited from its predecessors, in particular, the last one, the na49 experiment. important new detectors and upgrades of the legacy equipment were introduced by the na61 / shine collaboration. this paper describes the state of the na61 / shine facility - the beams and the detector system - before the cern long shutdown i, which started in march 2013.
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arxiv:1401.4699
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this paper develops a power management scheme that jointly optimizes the real power consumption of programmable loads and reactive power outputs of photovoltaic ( pv ) inverters in distribution networks. the premise is to determine the optimal demand response schedule that accounts for the stochastic availability of solar power, as well as to control the reactive power generation or consumption of pv inverters adaptively to the real power injections of all pv units. these uncertain real power injections by pv units are modeled as random variables taking values from a finite number of possible scenarios. through the use of second order cone relaxation of the power flow equations, a convex stochastic program is formulated. the objectives are to minimize the negative user utility, cost of power provision, and thermal losses, while constraining voltages to remain within specified levels. to find the global optimum point, a decentralized algorithm is developed via the alternating direction method of multipliers that results in closed - form updates per node and per scenario, rendering it suitable to implement in distribution networks with large number of scenarios. numerical tests and comparisons with an alternative deterministic approach are provided for typical residential distribution networks that confirm the efficiency of the algorithm.
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arxiv:1601.04023
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we prove the existence of approximate correlated equilibrium of support size polylogarithmic in the number of players and the number of actions per player. in particular, using the probabilistic method, we show that there exists a multiset of polylogarithmic size such that the uniform distribution over this multiset forms an approximate correlated equilibrium. along similar lines, we establish the existence of approximate coarse correlated equilibrium with logarithmic support. we complement these results by considering the computational complexity of determining small - support approximate equilibria. we show that random sampling can be used to efficiently determine an approximate coarse correlated equilibrium with logarithmic support. but, such a tight result does not hold for correlated equilibrium, i. e., sampling might generate an approximate correlated equilibrium of support size \ omega ( m ) where m is the number of actions per player. finally, we show that finding an exact correlated equilibrium with smallest possible support is np - hard under cook reductions, even in the case of two - player zero - sum games.
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arxiv:1308.6025
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we discuss a novel sparsity prior for compressive imaging in the context of the theory of compressed sensing with coherent redundant dictionaries, based on the observation that natural images exhibit strong average sparsity over multiple coherent frames. we test our prior and the associated algorithm, based on an analysis reweighted $ \ ell _ 1 $ formulation, through extensive numerical simulations on natural images for spread spectrum and random gaussian acquisition schemes. our results show that average sparsity outperforms state - of - the - art priors that promote sparsity in a single orthonormal basis or redundant frame, or that promote gradient sparsity. code and test data are available at https : / / github. com / basp - group / sopt.
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arxiv:1208.2330
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neurosymbolic ai is an emerging compositional paradigm that fuses neural learning with symbolic reasoning to enhance the transparency, interpretability, and trustworthiness of ai. it also exhibits higher data efficiency making it promising for edge deployments. despite the algorithmic promises and demonstrations, unfortunately executing neurosymbolic workloads on current hardware ( cpu / gpu / tpu ) is challenging due to higher memory intensity, greater compute heterogeneity and access pattern irregularity, leading to severe hardware underutilization. this work proposes cogsys, a characterization and co - design framework dedicated to neurosymbolic ai system acceleration, aiming to win both reasoning efficiency and scalability. on the algorithm side, cogsys proposes an efficient factorization technique to alleviate compute and memory overhead. on the hardware side, cogsys proposes a scalable neurosymbolic architecture with reconfigurable neuro / symbolic processing elements ( nspe ) and bubble streaming ( bs ) dataflow with spatial - temporal ( st ) mapping for highly parallel and efficient neurosymbolic computation. on the system side, cogsys features an adaptive workload - aware scheduler ( adsch ) to orchestrate heterogeneous kernels and enhance resource utilization. evaluated across cognitive workloads, cogsys enables reconfigurable support for neural and symbolic kernels and exhibits > 75x speedup over tpu - like systolic array with only < 5 % area overhead, as benchmarked under the tsmc 28nm technology node. cogsys achieves 4x - 96x speedup compared to desktop and edge gpus. for the first time, cogsys enables real - time abduction reasoning towards human fluid intelligence, requiring only 0. 3 s per reasoning task with 4 mm2 area and 1. 48 w power consumption.
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arxiv:2503.01162
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in this study, the influence of objects is investigated in the scenario of human action recognition with large number of classes. we hypothesize that the objects the humans are interacting will have good say in determining the action being performed. especially, if the objects are non - moving, such as objects appearing in the background, features such as spatio - temporal interest points, dense trajectories may fail to detect them. hence we propose to detect objects using pre - trained object detectors in every frame statically. trained deep network models are used as object detectors. information from different layers in conjunction with different encoding techniques is extensively studied to obtain the richest feature vectors. this technique is observed to yield state - of - the - art performance on hmdb51 and ucf101 datasets.
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arxiv:1512.06498
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the paper presents results from a psychophysical study conducted to optimize vibrotactile stimuli delivered to subject finger tips in order to evoke the somatosensory responses to be utilized next in a haptic brain computer interface ( hbci ) paradigm. we also present the preliminary eeg evoked responses for the chosen stimulating frequency. the obtained results confirm our hypothesis that the hbci paradigm concept is valid and it will allow for rapid stimuli presentation in order to improve information - transfer - rate ( itr ) of the bci.
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arxiv:1210.2942
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this paper provides some applications of the poisson cohomology groups introduced by flato, gerstenhaber and voronov. given an abelian extension of a poisson algebra by a representation, we first investigate the inducibility of a pair of poisson algebra automorphisms and show that the corresponding obstruction lies in the second poisson cohomology group. consequently, we obtain the wells exact sequence connecting various automorphism groups and the second poisson cohomology group. subsequently, we also consider the inducibility for a pair of poisson algebra derivations, obtain the obstruction and construct the corresponding wells - type exact sequence. to get another application, we introduce the notion of a ` deformation map ' in a proto - twilled poisson algebra. a deformation map unifies various well - known operators such as poisson homomorphisms, poisson derivations, crossed homomorphisms, rota - baxter operators of any weight, twisted rota - baxter operators, reynolds operators and modified rota - baxter operators on poisson algebras. we show that a deformation map $ r $ induces a new poisson algebra structure and a suitable representation of it. the corresponding poisson cohomology is defined to be the cohomology of the deformation map $ r $. finally, we study the formal deformations of the operator $ r $ in terms of the cohomology.
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arxiv:2504.06760
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the limitations and possibilities that the concept of quantum interference offers as a tool for testing fundamental physics are explored here. the use of neutron interference as an instrument to confront against measurement readouts some of the principles behind metric theories of gravity will be analyzed, as well as some discrepancies between theory and experiment. the main restrictions that this model embodies for the study of some of the features of the structure of space - - time will be explicitly pointed out. for instance, the conditions imposed by the necessary use of the semiclassical approximation. additionally, the role that photon interference could play as an element in this context is also considered. in this realm we explore the differences between first - order and second - order coherence experiments, and underline the fact that the hanbury - - brown - - twiss effect could open up some interesting experimental possibilities in the analysis of the structure of space - - time. the void, in connection with the description of wave phenomena, implicit in the principles of metric theories is analyzed. the conceptual difficulties, that this void entails, are commented.
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arxiv:0810.1325
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we utilize an isomorphism between the character rings of the odd orthogonal group and the orthosymplectic supergroup to understand equivariant positivity properties of the type b quadric hypersurface ring. our main result establishes a well - behaved functorial construction of schur modules ` ` with respect to ' ' the quadric hypersurface ring, an essential fact used by the authors in previous work to construct pure free resolutions. our techniques combine ideas from commutative algebra, lie theory, and algebraic geometry to understand representations of orthosymplectic supergroups and their corresponding type b counterparts.
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arxiv:2503.18918
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we consider a one - dimensional symmetric levy process that has local time. in the first part, we construct a self - adjoint extension of the generator of the process so that the constructed operator corresponds to the generator with the delta potential. using the constructed operator, we extend the feynman - kac formula to the case of delta function - type potentials and prove a limit theorem for an operator semigroup corresponding to this formula. in the second part, we construct a one - parameter family of distributions that attract the sample paths of the process to a given point. we show that this family weakly converges to the distribution of a feller process and prove a limit theorem for the distribution of a point where an attracted sample path comes.
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arxiv:2501.05522
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we study the nonlinear regime of large scale structure formation considering a dynamical dark energy ( de ) component determined by a steep equation of state parametrization ( seos ) $ w ( z ) = w _ 0 + w _ i \ frac { ( z / z _ t ) ^ q } { 1 + ( z / z _ t ) ^ q } $. in order to perform the model exploration at low computational cost, we modified the public code l - picola. we incorporate the de model by means of the first and second - order matter perturbations in the lagrangian frame and the expansion parameter. we analyze deviations of seos models with respect to $ \ lambda $ cdm in the non - linear matter power spectrum ( $ p _ k $ ), the halo mass function ( hmf ), and the two - point correlation function ( 2pcf ). on quantifying the nature of steep ( seos - i ) and smooth transitions in de field ( cpl - lim ), no signature of steep transition is observed, rather found the overall impact of de behaviors in $ p _ k $ at level of $ \ sim 2 - 3 \ % $ and $ \ sim 3 - 4 \ % $ differences w. r. t $ \ lambda $ cdm at $ z = 0 $ respectively. hmf shows the possibility to distinguish between the models at the high mass ends. the best - fitted model assuming only background and linear perturbations dubbed as seos - ii largely deviates from $ \ lambda $ cdm and current observations on studying the nonlinear growth. this large deviation in seos - ii also quantified the combined effect of the dynamical de and the larger amount of matter contained, $ \ omega _ { m0 } $ and $ h _ { 0 } $ accordingly. 2pcf results are relatively robust with $ \ sim 1 - 2 \ % $ deviation for seos - i and cpl - lim and a significant deviation for seos - ii throughout $ r $ from $ \ lambda $ cdm. finally, we conclude that the search for viable de models ( like the seos ) must include non - linear growth constraints.
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arxiv:1911.02402
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st engineering, is a global technology, defence and engineering group with a diverse portfolio of businesses across the aerospace, smart city, defence and public security segments. headquartered in singapore, the group reported a revenue of over s $ 11 billion in 2024 and ranks among the largest companies listed on the singapore exchange. it is a component stock of msci singapore, ftse straits times index and dow jones best - in - class asia pacific index. the group harnesses technology and innovation to solve real - world problems, enabling a more secure and sustainable world. it leverages synergies across the group and strategic partnerships externally to accelerate innovation, its strategic ai pillars, and its core technological and engineering capabilities. st engineering has more than 27, 000 employees with diverse background and skills, including over 19, 000 engineering and technical talents. = = history = = st engineering ' s history began with its precursor, the chartered industries of singapore, which was established in 1967 by the newly independent singaporean government as an ammunition manufacturer. businesses related to aerospace and shipbuilding were later created and put under the st umbrella. the st group of companies went commercial in 1990, setting up its first commercial airframe manufacturing, repair and overhaul facilities in singapore and the united states. st engineering was created in december 1997 as a merger of four listed companies : st aerospace, st electronics, st automative and st marine. its shares debuted on the singapore exchange on 8 december 1997. since then, st engineering has grown to become one of asia ' s largest defence and engineering groups for commercial and defence organisations across multiple industries. in mar 2007, st engineering was ranked 19th in the aerospace & defence industry and 1, 661th of 2, 000 of the world ' s largest public companies by forbes. in 2018, the group harmonised all brands by using " st engineering " as a masterbrand while in 2020, the group reorganised as commercial and defence & public security clusters, replacing the sector - structure of aerospace, electronics, land systems and marine. = = areas of business = = st engineering has a diverse portfolio of businesses and a global network of subsidiaries and associated companies across asia, europe, the middle east and the u. s. its commercial aerospace arm is the world ’ s largest third - party airframe mro solution provider and a premier mro for cfm leap engines. the businesses support aircraft operations and oem partners with aviation lifecycle solutions or holistic offerings for practically every stage of an aircraft ' s lifecycle. in 2024, its urban solutions
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https://en.wikipedia.org/wiki/ST_Engineering
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recently, level crossings in the energy bands of crystals have been identified as a key signature for topological phase transitions. using realistic models we show that the parameter space controlling the occurrence of level coincidences in energy bands has a much richer structure than anticipated previously. in particular, we identify robust level coincidences that cannot be removed by a small perturbation of the hamiltonian compatible with the crystal symmetry. different topological phases that are insulating in the bulk are then separated by a gapless ( metallic ) phase. we consider hgte / cdte quantum wells as a specific example.
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arxiv:1011.4504
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traffic flow forecasting is a highly challenging task due to the dynamic spatial - temporal road conditions. graph neural networks ( gnn ) has been widely applied in this task. however, most of these gnns ignore the effects of time - varying road conditions due to the fixed range of the convolution receptive field. in this paper, we propose a novel adaptive graph convolution networks ( agc - net ) to address this issue in gnn. the agc - net is constructed by the adaptive graph convolution ( agc ) based on a novel context attention mechanism, which consists of a set of graph wavelets with various learnable scales. the agc transforms the spatial graph representations into time - sensitive features considering the temporal context. moreover, a shifted graph convolution kernel is designed to enhance the agc, which attempts to correct the deviations caused by inaccurate topology. experimental results on two public traffic datasets demonstrate the effectiveness of the agc - net \ footnote { code is available at : https : / / github. com / zhengdaoli / agc - net } which outperforms other baseline models significantly.
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arxiv:2307.05517
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the technique of dispersion integration over the mass of composite particle is used to describe the reaction of the deuteron photodisintegration. the influence of the final state interaction ( fsi ) on the total cross section, calculated with and without inelasticity is investigated. numerical results depend on the choice of the vertex function for the isobar photoproduction.
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arxiv:nucl-th/9510008
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in this work, we first use thompson ' s renormalization group method to treat qcd - vacuum behavior close to the regime of asymptotic freedom. qcd - vacuum behaves effectively like a " paramagnetic system " of a classical theory in the sense that virtual color charges ( gluons ) emerge in it as spin effect of a paramagnetic material when a magnetic field aligns their microscopic magnetic dipoles. making a classical analogy with the paramagnetism of landau ' s theory, we are able to introduce a kind of landau effective action without temperature and phase transition for simply representing qcd - vacuum behavior at higher energies as magnetization of a paramagnetic material in the presence of a magnetic field h. this reasoning allows us to use thompson ' s heuristic approach in order to extract an " effective susceptibility " ( $ \ chi > 0 $ ) of qcd - vacuum. it depends on logarithmic of energy scale u to investigate hadronic matter. consequently, we are able to get an " effective magnetic permeability " ( $ \ mu > 1 $ ) of such a " paramagnetic vacuum ". as qcd - vacuum must obey lorentz invariance, the attainment of $ \ mu > 1 $ must simply require that the " effective electrical permissivity " is $ \ epsilon < 1 $, in such a way that $ \ mu \ epsilon = 1 $ ( c ^ 2 = 1 ). this leads to the antiscreening effect, where the asymptotic freedom takes place. on the other hand, quarks cofinement, a subject which is not treatable by perturbative calculations, is worked by the present approach. we apply the method to study this subject in order to obtain the string constant, which is in agreement with the experiments.
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arxiv:0706.2553
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we prove q - analogues of two ramanujan - type series for $ 1 / \ pi $ from $ q $ - analogues of ordinary wz pairs.
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arxiv:1803.08477
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we fully investigate the symmetry breaking patterns occurring upon creation of composite non - abelian strings : vortex strings in non - abelian theories where different sets of colours have different amounts of flux. after spontaneous symmetry breaking, there remains some internal colour degrees of freedom attached to these objects, which we argue must exist in a flag manifold, a more general kind of projective space than both $ \ mathbb { cp } ( n ) $ and the grassmannian manifold. these strings are expected to be bps, since its constituents are. we demonstrate that this is true and construct a low - energy effective action for the fluctuations of the internal flag moduli, which we then re - write it in two different ways for the dynamics of these degrees of freedom : a gauged linear sigma model with auxiliary fields and a non - linear sigma model with an explicit target space metric for the flag manifolds, both of which $ \ mathcal { n } = ( 2, 2 ) $ supersymmetric. we finish by performing some groundwork analysis of the resulting theory.
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arxiv:1908.08499
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we consider a class of " filtered " schemes for first order time dependent hamilton - jacobi equations and prove a general convergence result for this class of schemes. a typical filtered scheme is obtained mixing a high - order scheme and a monotone scheme according to a filter function $ f $ which decides where the scheme has to switch from one scheme to the other. a crucial role for this switch is played by a parameter $ \ varepsilon = \ varepsilon ( { \ delta t, \ delta x } ) > 0 $ which goes to 0 as the time and space steps $ ( \ delta t, \ delta x ) $ are going to 0 and does not depend on the time $ t _ n $, for each iteration $ n $. the tuning of this parameter in the code is rather delicate and has an influence on the global accuracy of the filtered scheme. here we introduce an adaptive and automatic choice of $ \ varepsilon = \ varepsilon ^ n ( \ delta t, \ delta x ) $ at every iteration modifying the classical set up. the adaptivity is controlled by a smoothness indicator which selects the regions where we modify the regularity threshold $ \ varepsilon ^ n $. a convergence result and some error estimates for the new adaptive filtered scheme are proved, this analysis relies on the properties of the scheme and of the smoothness indicators. finally, we present some numerical tests to compare the adaptive filtered scheme with other methods.
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arxiv:1812.02140
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accurate and fast beam - alignment is essential to cope with the fast - varying environment in millimeter - wave communications. a data - driven approach is a promising solution to reduce the training overhead by leveraging side information and on - the - field measurements. in this work, a two - stage tensor completion algorithm is proposed to predict the received power on a set of possible users ' positions, given received power measurements on a small subset of positions. based on these predictions and on positional side information, a small subset of beams is recommended to reduce the training overhead of beam - alignment. numerical results evaluated with the quadriga channel simulator demonstrate that the proposed algorithm achieves correct alignment with high probability using small training overhead : given power measurement on only 20 % of the possible positions when using a discrete coverage area, our algorithm attains a probability of correct alignment of 80 %, with only 2 % of trained beams, as opposed to a state - of - the - art scheme which achieves 50 % correct alignment in the same configuration. to the best of our knowledge, this is the first work to consider the beam recommendation problem based on measurements collected on a small subset of positions.
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arxiv:1906.07290
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pursuit - evasion games ( in discrete time ) are stochastic games with nonnegative daily payoffs, with the final payoff being the cumulative sum of payoffs during the game. we show that such games admit a value even in the presence of incomplete information and that this value is uniform, i. e. there are epsilon - optimal strategies for both players that are epsilon - optimal in any long enough prefix of the game. we give an example to demonstrate that nonnegativity is essential and expand the results to leavable games.
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arxiv:0708.2556
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the well known douglas lemma says that for operators $ a, b $ on hilbert space that $ aa ^ * - bb ^ * \ succeq 0 $ implies $ b = ac $ for some contraction operator $ c $. the result carries over directly to classical operator - valued toeplitz operators by simply replacing operator by toeplitz operator. free functions generalize the notion of free polynomials and formal power series and trace back to the work of j. taylor in the 1970s. they are of current interest, in part because of their connections with free probability and engineering systems theory. for free functions $ a $ and $ b $ on a free domain $ \ ck $ defined free polynomial inequalities, a sufficient condition on the difference $ aa ^ * - bb ^ * $ to imply the existence a free function $ c $ taking contractive values on $ \ ck $ such that $ a = bc $ is established. the connection to recent work of agler and mccarthy and their free toeplitz corona theorem is exposited.
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arxiv:1411.1965
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in the realm of modern digital communication, cryptography, and signal processing, binary sequences with a low correlation properties play a pivotal role. in the literature, considerable efforts have been dedicated to constructing good binary sequences of various lengths. as a consequence, numerous constructions of good binary sequences have been put forward. however, the majority of known constructions leverage the multiplicative cyclic group structure of finite fields $ \ mathbb { f } _ { p ^ n } $, where $ p $ is a prime and $ n $ is a positive integer. recently, the authors made use of the cyclic group structure of all rational places of the rational function field over the finite field $ \ mathbb { f } _ { p ^ n } $, and firstly constructed good binary sequences of length $ p ^ n + 1 $ via cyclotomic function fields over $ \ mathbb { f } _ { p ^ n } $ for any prime $ p $ \ cite { hjmx24, jmx22 }. this approach has paved a new way for constructing good binary sequences. motivated by the above constructions, we exploit the cyclic group structure on rational points of elliptic curves to design a family of binary sequences of length $ 2 ^ n + 1 + t $ with a low correlation for many given integers $ | t | \ le 2 ^ { ( n + 2 ) / 2 } $. specifically, for any positive integer $ d $ with $ \ gcd ( d, 2 ^ n + 1 + t ) = 1 $, we introduce a novel family of binary sequences of length $ 2 ^ n + 1 + t $, size $ q ^ { d - 1 } - 1 $, correlation bounded by $ ( 2d + 1 ) \ cdot 2 ^ { ( n + 2 ) / 2 } + | t | $, and a large linear complexity via elliptic curves.
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arxiv:2407.18570
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personalized recommendations on the netflix homepage are based on a user ' s viewing habits and the behavior of similar users. these recommendations, organized for efficient browsing, enable users to discover the next great video to watch and enjoy without additional input or an explicit expression of their intents or goals. the netflix search experience, on the other hand, allows users to take active control of discovering new videos by explicitly expressing their entertainment needs via search queries. in this talk, we discuss the importance of producing search results that go beyond traditional keyword - matches to effectively satisfy users ' search needs in the netflix entertainment setting. motivated by users ' various search intents, we highlight the necessity to improve search by applying approaches that have historically powered the homepage. specifically, we discuss our approach to leverage recommendations in the context of search and to effectively organize search results to provide a product experience that meaningfully adds value for our users.
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arxiv:2105.14134
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bestvina, feighn and handel proved that every subgroup of the outer automorphism group, $ \ textrm { out } ( f _ n ) $, of the free group of rank $ n $ is either virtually finitely generated abelian or contains a nonabelian free group. in this note we consider the more general situation of the outer automorphism group $ \ textrm { out } ( g ) $ of a finitely generated free - by - finite group $ g $. we show that $ \ textrm { out } ( g ) $ is translation discrete and that every subgroup of $ \ textrm { out } ( g ) $ is either virtually finitely generated abelian or contains a nonabelian free group.
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arxiv:2112.12183
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the combined dyson - schwinger - - bethe - salpeter equations are employed at non - zero temperature. the truncations refer to a rainbow - ladder approximation augmented with an interaction kernel which facilitates a special temperature dependence. at low temperatures, $ t \ to 0 $, we recover a quark propagator from the dyson - schwinger ( gap ) equation which delivers, e. g. mass functions $ b $, quark renormalization wave function $ a $, and two - quark condensate $ \ la q \ bar q \ ra $ smoothly interpolating to the $ t = 0 $ results, despite the broken o ( 4 ) symmetry in the heat bath and discrete matsubara frequencies. besides the matsubara frequency difference entering the interaction kernel, often a debye screening mass term is introduced when extending the $ t = 0 $ kernel to non - zero temperatures. at larger temperatures, however, we are forced to drop this debye mass in the infra - red part of the longitudinal interaction kernel to keep the melting of the two - quark condensate in a range consistent with lattice qcd results. utilizing that quark propagator for the first few hundred fermion matsubara frequencies we evaluate the bethe - salpeter vertex function in the pseudo - scalar $ q \ bar q $ channel for the lowest boson matsubara frequencies and find a competition of $ q \ bar q $ bound states and quasi - free two - quark states at $ t = { \ cal o } $ ( 100 mev ). this indication of pseudo - scalar meson dissociation below the anticipated qcd deconfinement temperature calls for an improvement of the approach, which is based on an interaction adjusted to the meson spectrum at $ t = 0 $.
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arxiv:1807.10075
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using frequency distributions of daily closing price time series of several financial market indexes, we investigate whether the bias away from an equiprobable sequence distribution found in the data, predicted by algorithmic information theory, may account for some of the deviation of financial markets from log - normal, and if so for how much of said deviation and over what sequence lengths. we do so by comparing the distributions of binary sequences from actual time series of financial markets and series built up from purely algorithmic means. our discussion is a starting point for a further investigation of the market as a rule - based system with an ' algorithmic ' component, despite its apparent randomness, and the use of the theory of algorithmic probability with new tools that can be applied to the study of the market price phenomenon. the main discussion is cast in terms of assumptions common to areas of economics in agreement with an algorithmic view of the market.
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arxiv:1008.1846
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the scheduling of task graphs with communication delays has been extensively studied. recently, new results for the common sub - case of fork - join shaped task graphs were published, including an eptas and polynomial algorithms for special cases. these new results modelled the target architecture to consist of homogeneous processors. however, forms of heterogeneity become more and more common in contemporary parallel systems, such as cpu - - accelerator systems, with their two types of resources. in this work, we study the scheduling of fork - join task graphs with communication delays, which is representative of highly parallel workloads, onto heterogeneous systems of related processors. we present an epas, and some polynomial time algorithms for special cases, such as with equal processing costs or unlimited resources. lastly, we briefly look at the above described case of two resource - types and its implications. it is interesting to note, that all results here also apply to scheduling independent tasks with release times and deadlines.
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arxiv:2305.17556
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searches for neutrino isocurvature usually constrain a specific linear combination of isocurvature perturbations. in this work, we discuss realistic cosmological scenarios giving rise to neutrino isocurvature. we show that in general both, neutrino and matter isocurvature perturbations are generated, whose ratio we parameterize by a newly introduced mixing angle. we obtain the first limits on this new mixing angle from planck data, and discuss novel insights into the early universe that could be provided by future measurements.
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arxiv:2504.17047
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extending previous works on the spectrum of qcd _ 2, we now investigate the 2d analogue of meson - baryon scattering. we use semi - classical methods, perturbing around classical soliton solutions. we start with the abelian case, corresponding to one flavor, and find that in this case the effective potential is reflectionless. we obtain an explicit expression for the forward phase shift. in the non - abelian case of several flavors, the method yields a potential which depends on the momentum of the incoming particle. in this case there is both transmission and reflection. in both cases no resonances appear. as a byproduct, we derive the general conditions for a 2d quantum field theoretical action to yield a reflectionless effective potential when one expands in small fluctuations about the classical solution.
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arxiv:hep-ph/0206001
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we analyze rest - frame optical morphologies and gas - phase kinematics as traced by rest - frame far - uv and optical spectra for a sample of 204 star forming galaxies in the redshift range z ~ 2 - 3 drawn from the keck baryonic structure survey ( kbss ). we find that spectroscopic properties and gas - phase kinematics are closely linked to morphology : compact galaxies with semi - major axis radii r < ~ 2 kpc are substantially more likely than their larger counterparts to exhibit lya in emission. although lya emission strength varies widely within galaxies of a given morphological type, all but one of 19 galaxies with lya equivalent width w _ lya > 20 angstroms have compact and / or multiple - component morphologies with r < = 2. 5 kpc. the velocity structure of absorption lines in the galactic continuum spectra also varies as a function of morphology. galaxies of all morphological types drive similarly strong outflows ( as traced by the blue wing of interstellar absorption line features ), but the outflows of larger galaxies are less highly ionized and exhibit larger optical depth at the systemic redshift that may correspond to a decreasing efficiency of feedback in evacuating gas from the galaxy. this v ~ 0 km / s gas is responsible both for shifting the mean absorption line redshift and attenuating w _ lya ( via a longer resonant scattering path ) in galaxies with larger rest - optical half light radii. in contrast to galaxies at lower redshifts, there is no evidence for a correlation between outflow velocity and inclination, suggesting that outflows from these puffy and irregular systems may be poorly collimated. ( abbrev. )
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arxiv:1206.6889
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let $ k $ be an algebraically closed field of characteristic $ p > 0 $. let $ d $ be a $ p $ - divisible group over $ k $. let $ n _ d $ be the smallest non - negative integer for which the following statement holds : if $ c $ is a $ p $ - divisible group over $ k $ of the same codimension and dimension as $ d $ and such that $ c [ p ^ { n _ d } ] $ is isomorphic to $ d [ p ^ { n _ d } ] $, then $ c $ is isomorphic to $ d $. to the dieudonn \ ' e module of $ d $ we associate a non - negative integer $ \ ell _ d $ which is a computable upper bound of $ n _ d $. if $ d $ is a product $ \ prod _ { i \ in i } d _ i $ of isoclinic $ p $ - divisible groups, we show that $ n _ d = \ ell _ d $ ; if the set $ i $ has at least two elements we also show that $ n _ d \ le \ max \ { 1, n _ { d _ i }, n _ { d _ i } + n _ { d _ j } - 1 | i, j \ in i, j \ neq i \ } $. we show that we have $ n _ d \ le 1 $ if and only if $ \ ell _ d \ le 1 $ ; this recovers the classification of minimal $ p $ - divisible groups obtained by oort. if $ d $ is quasi - special, we prove the traverso truncation conjecture for $ d $. if $ d $ is $ f $ - cyclic, we compute explicitly $ n _ d $. many results are proved in the general context of latticed $ f $ - isocrystals with a ( certain ) group over $ k $.
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arxiv:math/0607268
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deep hiding, concealing secret information using deep neural networks ( dnns ), can significantly increase the embedding rate and improve the efficiency of secret sharing. existing works mainly force on designing dnns with higher embedding rates or fancy functionalities. in this paper, we want to answer some fundamental questions : how to increase and what determines the embedding rate of deep hiding. to this end, we first propose a novel local deep hiding ( ldh ) scheme that significantly increases the embedding rate by hiding large secret images into small local regions of cover images. our scheme consists of three dnns : hiding, locating, and revealing. we use the hiding network to convert a secret image in a small imperceptible compact secret code that is embedded into a random local region of a cover image. the locating network assists the revealing process by identifying the position of secret codes in the stego image, while the revealing network recovers all full - size secret images from these identified local regions. our ldh achieves an extremely high embedding rate, i. e., $ 16 \ times24 $ bpp and exhibits superior robustness to common image distortions. we also conduct comprehensive experiments to evaluate our scheme under various system settings. we further quantitatively analyze the trade - off between the embedding rate and image quality with different image restoration algorithms.
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arxiv:2302.11918
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the aim of this article is to extend the results of asadi m. b, b. v. r. bhat, g. ramesh, k. sumesh about completely positive maps on hilbert c * - modules. we prove a stinespring type theorem for a finite family of completely positive maps on hilbert c * - modules. we also show that any two minimal stinespring representations are unitarily equivalent.
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arxiv:1210.5716
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experiments have shown that the conductance of conical channels, filled with an aqueous electrolyte, can strongly depend on the history of the applied voltage. these channels hence have a memory and are promising elements in brain - inspired ( iontronic ) circuits. we show here that the memory of such channels stems from transient concentration polarization over the ionic diffusion time. we derive an analytic approximation for these dynamics which shows good agreement with full finite - element calculations. using our analytic approximation, we propose an experimentally realisable hodgkin - huxley iontronic circuit where micrometer cones take on the role of sodium and potassium channels. our proposed circuit exhibits key features of neuronal communication such as all - or - none action potentials upon a pulse stimulus and a spike train upon a sustained stimulus.
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arxiv:2301.06158
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recent research using reinforcement learning ( rl ) to learn autonomous control for spacecraft operations has shown great success. however, a recent study showed their performance could be improved by changing the action space, i. e. control outputs, used in the learning environment. this has opened the door for finding more improvements through further changes to the environment. the work in this paper focuses on how changes to the environment ' s observation space can impact the training and performance of rl agents learning the spacecraft inspection task. the studies are split into two groups. the first looks at the impact of sensors that were designed to help agents learn the task. the second looks at the impact of reference frames, reorienting the agent to see the world from a different perspective. the results show the sensors are not necessary, but most of them help agents learn more optimal behavior, and that the reference frame does not have a large impact, but is best kept consistent.
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arxiv:2501.06016
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the delphi and aleph experiments have released new results of the fermi - dirac correlations for pp ( \ bar { p } \ bar { p } ) and bose - einstein correlations for k ^ 0 _ s k ^ 0 _ s. both experiments measure very small source radius for protons r \ sim 0. 1 fm. the source dimension for k ^ 0 _ s k ^ 0 _ s is in agreement with the previous measurements for k ^ + k ^ -, k ^ 0 _ s k ^ 0 _ s. these results, together with earlier lep measurements, establish the dependence of the correlation radius on the hadron mass. this paper discusses some of the attempts to describe this phenomenon.
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arxiv:hep-ex/0405057
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we present the first measurement of the galaxy luminosity function at 1500a between 0. 2 < z < 1. 2 based on galex - vvds observations ( 1000 spectroscopic redshifts for galaxies with nuv < 24. 5 ) and at higher z using existing datasets. our main results are summarized as follows : ( i ) luminosity evolution is observed with delta ( mstar ) = - 2. 0 mag between z = 0 and z = 1 and delta ( mstar ) = - 1. 0mag between z = 1 and z = 3. this confirms that the star formation activity was significantly higher in the past. ( ii ) the lf slopes vary between - 1. 2 < alpha < - 1. 65, with a marginally significant hint of increase at higher z. ( iii ) we split the sample in three restframe ( b - i ) intervals providing an approximate spectral type classification : sb - sd, sd - irr and unobscured starbursts. we find that the bluest class evolves less strongly in luminosity than the two other classes. on the other hand their number density increases sharply with z ( 15 % in the local universe to 55 % at z = 1 ) while that of the reddest classes decreases.
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arxiv:astro-ph/0411391
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we provide an effective method to compute multiplier ideals of meromorphic functions in dimension two. we also prove that meromorphic functions only have integer jumping numbers after reaching some threshold.
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arxiv:2405.04745
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this work presents an investigation on different methods for the calculation of the angle of attack and the underlying induced velocity on wind turbine blades using data obtained from three - dimensional computational fluid dynamics ( cfd ). several methods are examined and their advantages, as well as shortcomings, are presented. the investigations are performed for two 10mw reference wind turbines under axial inflow conditions, namely the turbines designed in the eu avatar and innwind. eu projects. the results show that the evaluated methods are in good agreement with each other at the mid - span, though some deviations are observed at the root and tip regions of the blades. this indicates that cfd results can be used for the calibration of induction modeling for blade element momentum ( bem ) tools. moreover, using any of the proposed methods, it is possible to obtain airfoil characteristics for lift and drag coefficients as a function of the angle of attack.
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arxiv:1709.04298
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autoformalization is the process of automatically translating from natural language mathematics to formal specifications and proofs. a successful autoformalization system could advance the fields of formal verification, program synthesis, and artificial intelligence. while the long - term goal of autoformalization seemed elusive for a long time, we show large language models provide new prospects towards this goal. we make the surprising observation that llms can correctly translate a significant portion ( $ 25. 3 \ % $ ) of mathematical competition problems perfectly to formal specifications in isabelle / hol. we demonstrate the usefulness of this process by improving a previously introduced neural theorem prover via training on these autoformalized theorems. our methodology results in a new state - of - the - art result on the minif2f theorem proving benchmark, improving the proof rate from $ 29. 6 \ % $ to $ 35. 2 \ % $.
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arxiv:2205.12615
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the relation between the r - and p - matrix approaches and the harmonic oscillator representation of the quantum scattering theory ( j - matrix method ) is discussed. we construct a discrete analogue of the p - matrix that is shown to be equivalent to the usual p - matrix in the quasiclassical limit. a definition of the natural channel radius is introduced. as a result, it is shown to be possible to use well - developed technique of r - and p - matrix theory for calculation of resonant states characteristics, scattering phase shifts, etc., in the approaches based on harmonic oscillator expansions, e. g., in nuclear shell - model calculations. p - matrix is used also for formulation of the method of treating coulomb asymptotics in the scattering theory in oscillator representation.
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arxiv:math-ph/9910007
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let $ v _ \ gamma $ be a lattice periodic potential and $ a $ and $ \ phi $ external electromagnetic potentials which vary slowly on the scale set by the lattice spacing. it is shown that the wigner function of a solution of the schroedinger equation with hamiltonian operator $ h = { 1 / 2 } ( - \ i \ nabla _ x - a ( \ epsilon x ) ) ^ 2 + v _ \ gamma ( x ) + \ phi ( \ epsilon x ) $ propagates along the flow of the semiclassical model of solid states physics up an error of order $ \ epsilon $. if $ \ epsilon $ - dependent corrections to the flow are taken into account, the error is improved to order $ \ epsilon ^ 2 $. we also discuss the propagation of the wigner measure. the results are obtained as corollaries of an egorov type theorem proved in a previous paper ( math - ph / 0212041 ).
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arxiv:math-ph/0403037
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we develop a perturbative expansion which allows the construction of non - abelian self - dual su ( 2 ) yang - mills field configurations on the four - dimensional torus with topological charge 1 / 2. the expansion is performed around the constant field strength abelian solutions found by ' t hooft. next to leading order calculations are compared with numerical results obtained with lattice gauge theory techniques.
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arxiv:hep-th/0007113
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using a fully ab - initio methodology, we demonstrate how the lattice vibrations couple with neutral excitons in monolayer wse2 and contribute to the non - radiative excitonic lifetime. we show that only by treating the electron - electron and electron - phonon interactions at the same time it is possible to obtain an unprecedented agreement of the zero and finite - temperature optical gaps and absorption spectra with the experimental results. the bare energies were calculated by solving the kohn - sham equations, whereas g $ _ { 0 } $ w $ _ { 0 } $ many body perturbation theory was used to extract the excited state energies. a coupled electron - hole bethe - salpeter equation was solved incorporating the polaronic energies to show that it is the in - plane torsional acoustic phonon branch that contributes mostly to the a and b exciton build - up. we find that the three a, b and c excitonic peaks exhibit different behaviour with temperature, displaying different non - radiative linewidths. there is no considerable transition in the strength of the excitons with temperature but a - exciton exhibits darker nature in comparison to c - exciton. further, all the excitonic peaks redshifts as temperature rises. renormalization of the bare electronic energies by phonon interactions and the anharmonic lattice thermal expansion causes a decreasing band - gap with increasing temperature. the zero point energy renormalization ( 31 mev ) is found to be entirely due to the polaronic interaction with negligible contribution from lattice anharmonicites. these findings may find a profound impact on electronic and optoelectronic device technologies based on these monolayers.
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arxiv:1805.01794
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ultraluminous x - ray sources ( ulxs ) are mainly powered by accretion in neutron stars or stellar - mass black holes. accreting at rates exceeding the eddington limit by factors of a few up to hundreds, radiation pressure is expected to inflate the accretion disc, and drive fast winds that have in fact been observed at significant fractions of the speed of light. given the super - eddington luminosity, the accretion disc will be thicker than in sub - eddington accretors such as common active galactic nuclei and x - ray binaries, leading to a different spectral energy distribution and, possibly, a different thermal status of the wind. here we show the first attempt to calculate the photoionization balance of the winds driven by strong radiation pressure in thick discs with a focus on ulxs hosting black holes or non - magnetic neutron stars. we find that the winds are generally in thermally stable equilibrium, but long - term variations in the accretion rate and the inclination due to precession may have significant effects on the wind appearance and stability. our model trends can explain the observed correlation between the spectral residuals around 1 kev and the ulx spectral state. we also find a possible correlation between the spectral hardness of the ulx, the wind velocity and the ionization parameter in support of the general scenario.
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arxiv:1903.06174
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following openai ' s introduction of gpts, a surge in gpt apps has led to the launch of dedicated llm app stores. nevertheless, given its debut, there is a lack of sufficient understanding of this new ecosystem. to fill this gap, this paper presents a first comprehensive longitudinal ( 5 - month ) study of the evolution, landscape, and vulnerability of the emerging llm app ecosystem, focusing on two gpt app stores : \ textit { gptstore. ai } and the official \ textit { openai gpt store }. specifically, we develop two automated tools and a trilevel configuration extraction strategy to efficiently gather metadata ( \ ie names, creators, descriptions, \ etc ) and user feedback for all gpt apps across these two stores, as well as configurations ( \ ie system prompts, knowledge files, and apis ) for the top 10, 000 popular apps. our extensive analysis reveals : ( 1 ) the user enthusiasm for gpt apps consistently rises, whereas creator interest plateaus within three months of gpts ' launch ; ( 2 ) nearly 90 \ % system prompts can be easily accessed due to widespread failure to secure gpt app configurations, leading to considerable plagiarism and duplication among apps. our findings highlight the necessity of enhancing the llm app ecosystem by the app stores, creators, and users.
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arxiv:2402.15105
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in recent years, it has become easy to obtain location information quite precisely. however, the acquisition of such information has risks such as individual identification and leakage of sensitive information, so it is necessary to protect the privacy of location information. for this purpose, people should know their location privacy preferences, that is, whether or not he / she can release location information at each place and time. however, it is not easy for each user to make such decisions and it is troublesome to set the privacy preference at each time. therefore, we propose a method to recommend location privacy preferences for decision making. comparing to existing method, our method can improve the accuracy of recommendation by using matrix factorization and preserve privacy strictly by local differential privacy, whereas the existing method does not achieve formal privacy guarantee. in addition, we found the best granularity of a location privacy preference, that is, how to express the information in location privacy protection. to evaluate and verify the utility of our method, we have integrated two existing datasets to create a rich information in term of user number. from the results of the evaluation using this dataset, we confirmed that our method can predict location privacy preferences accurately and that it provides a suitable method to define the location privacy preference.
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arxiv:1904.10578
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we review and provide simplified proofs related to the magnus expansion, and improve convergence estimates. observations and improvements concerning the baker - - campbell - - hausdorff expansion are also made. in this part i, we consider the general banach algebraic setting. we show that the ( cumulative ) convergence radius of the magnus expansion is $ 2 $ ; and of the baker - - campbell - - hausdorff series is $ \ mathrm c _ 2 = 2. 89847930 \ ldots $. more generally, the resolvent method is developed in the analytic setting.
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arxiv:1709.01791
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we define an annular version of odd khovanov homology and prove that it carries an action of the lie superalgebra $ \ mathfrak { gl } ( 1 | 1 ) $ which is preserved under annular reidemeister moves.
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arxiv:1806.05718
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recently, an end - to - end two - dimensional sound source localization algorithm with ad - hoc microphone arrays formulates the sound source localization problem as a classification problem. the algorithm divides the target indoor space into a set of local areas, and predicts the local area where the speaker locates. however, the local areas are encoded by one - hot code, which may lose the connections between the local areas due to quantization errors. in this paper, we propose a new soft label coding method, named label smoothing, for the classification - based two - dimensional sound source location with ad - hoc microphone arrays. the core idea is to take the geometric connection between the classes into the label coding process. the first one is named static soft label coding ( sslc ), which modifies the one - hot codes into soft codes based on the distances between the local areas. because sslc is handcrafted which may not be optimal, the second one, named dynamic soft label coding ( dslc ), further rectifies sslc, by learning the soft codes according to the statistics of the predictions produced by the classification - based localization model in the training stage. experimental results show that the proposed methods can effectively improve the localization accuracy.
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arxiv:2304.07512
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we study the problem of low - rank matrix completion for symmetric matrices. the minimum rank of a completion of a generic partially specified symmetric matrix depends only on the location of the specified entries, and not their values, if complex entries are allowed. when the entries are required to be real, this is no longer the case and the possible minimum ranks are called typical ranks. we give a combinatorial description of the patterns of specified entires of $ n \ times n $ symmetric matrices that have $ n $ as a typical rank. moreover, we describe exactly when such a generic partial matrix is minimally completable to rank $ n $. we also characterize the typical ranks for patterns of entries with low maximal typical rank.
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arxiv:1909.06593
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we establish a stochastic maximum principle ( smp ) for control problems of partially observed diffusions of mean - field type with risk - sensitive performance functionals.
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arxiv:1411.7231
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a trial application of the method of feynman - kleinert approximants is made to perturbation series arising in connection with the lattice schwinger model. in extrapolating the lattice strong - coupling series to the weak - coupling continuum limit, the approximants do not converge well. in interpolating between the continuum perturbation series at large fermion mass and small fermion mass, however, the approximants do give good results. in the course of the calculations, we picked up and rectified an error in an earlier derivation of the continuum series coefficients.
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arxiv:hep-lat/0303007
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dual - comb spectroscopy is a rapidly developing technique enabling ultraprecise broadband optical diagnostics of atoms and molecules. this powerful tool typically requires two phase - locked femtosecond lasers, yet it has been shown that it can be realized without any stabilization if the combs are generated from a single laser cavity. still, unavoidable intrinsic relative phase - fluctuations always set a limit on the precision of any spectroscopic measurements, hitherto limiting the applicability of bulk dual - comb lasers for mode - resolved studies. here, we demonstrate a versatile concept for low - noise dual - comb generation from a single - cavity femtosecond solid - state laser based on intrinsic polarization - multiplexing inside an optically anisotropic gain crystal. due to intracavity spatial separation of the orthogonally - polarized beams, two sub - 100 fs pulse trains are simultaneously generated from a 1. 05 $ \ mu $ m yb : cngs oscillator with a repetition rate difference of 4. 7 khz. the laser exhibits the lowest relative noise ever demonstrated for a bulk dual - comb source, supporting free - running mode - resolved spectroscopic measurements over a second. moreover, the developed dual - comb generation technique can be applied to any solid - state laser exploiting a birefringent active crystal, paving the way towards a new class of highly - coherent, single - cavity, dual - comb laser sources operating in various spectral regions.
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arxiv:2009.05454
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agol recently introduced the concept of a veering taut triangulation, which is a taut triangulation with some extra combinatorial structure. we define the weaker notion of a " veering triangulation " and use it to show that all veering triangulations admit strict angle structures. we also answer a question of agol, giving an example of a veering taut triangulation that is not layered.
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arxiv:1011.3695
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the audio - video based multimodal emotion recognition has attracted a lot of attention due to its robust performance. most of the existing methods focus on proposing different cross - modal fusion strategies. however, these strategies introduce redundancy in the features of different modalities without fully considering the complementary properties between modal information, and these approaches do not guarantee the non - loss of original semantic information during intra - and inter - modal interactions. in this paper, we propose a novel cross - modal fusion network based on self - attention and residual structure ( cfn - sr ) for multimodal emotion recognition. firstly, we perform representation learning for audio and video modalities to obtain the semantic features of the two modalities by efficient resnext and 1d cnn, respectively. secondly, we feed the features of the two modalities into the cross - modal blocks separately to ensure efficient complementarity and completeness of information through the self - attention mechanism and residual structure. finally, we obtain the output of emotions by splicing the obtained fused representation with the original representation. to verify the effectiveness of the proposed method, we conduct experiments on the ravdess dataset. the experimental results show that the proposed cfn - sr achieves the state - of - the - art and obtains 75. 76 % accuracy with 26. 30m parameters. our code is available at https : / / github. com / skeletonnn / cfn - sr.
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arxiv:2111.02172
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the one dimensional spin - 1 / 2 heisenberg antiferromagnet in a weak magnetic field h is studied using the bosonization method. we derive a set of renormalization group equations. the fixed point is reached when the field is scaled to the value at which the system is quarter - filled. as the magnetic field varies, a continuum line of fixed points is formed. we compute the uniform longitudinal susceptibility $ \ chi _ z ( h ) $. the singular behavior of $ \ chi _ z ( h ) $ as $ h \ to 0 $ is found to be contained in $ 1 / \ ln ( h _ o / h ) $ with $ h _ o $ a non - universal constant. the spin - spin correlations in the magnetic field are calculated.
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arxiv:cond-mat/0002104
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as constructing multi - d wavelets remains a challenging problem, we propose a new method called prime coset sum to construct multi - d wavelets. our method provides a systematic way to construct multi - d non - separable wavelet filter banks from two 1 - d lowpass filters, with one of whom being interpolatory. our method has many important features including the following : 1 ) it works for any spatial dimension, and any prime scalar dilation, 2 ) the vanishing moments of the multi - d wavelet filter banks are guaranteed by certain properties of the initial 1 - d lowpass filters, and furthermore, 3 ) the resulting multi - d wavelet filter banks are associated with fast algorithms that are faster than the existing fast tensor product algorithms.
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arxiv:1407.5513
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