text
null | inputs
dict | prediction
null | prediction_agent
null | annotation
list | annotation_agent
null | multi_label
bool 1
class | explanation
null | id
stringlengths 1
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{
"abstract": " In this letter we establish Yangian symmetry of planar N=4 super-Yang-Mills\ntheory. We prove that the classical equations of motion of the model close onto\nthemselves under the action of Yangian generators. Moreover we propose an\noff-shell extension of our statement which is equivalent to the invariance of\nthe action and prove that it is exactly satisfied. We assert that our\nrelationship serves as a criterion for integrability in planar gauge theories\nby explicitly checking that it applies to integrable ABJM theory but not to\nnon-integrable N=1 super-Yang-Mills theory.\n",
"title": "Yangian Symmetry and Integrability of Planar N=4 Super-Yang-Mills Theory"
}
| null | null | null | null | true | null |
3501
| null |
Default
| null | null |
null |
{
"abstract": " Conventional dark matter direct detection experiments set stringent\nconstraints on dark matter by looking for elastic scattering events between\ndark matter particles and nuclei in underground detectors. However these\nconstraints weaken significantly in the sub-GeV mass region, simply because\nlight dark matter does not have enough energy to trigger detectors regardless\nof the dark matter-nucleon scattering cross section. Even if future experiments\nlower their energy thresholds, they will still be blind to parameter space\nwhere dark matter particles interact with nuclei strongly enough that they lose\nenough energy and become unable to cause a signal above the experimental\nthreshold by the time they reach the underground detector. Therefore in case\ndark matter is in the sub-GeV region and strongly interacting, possible\nunderground scatterings of dark matter with terrestrial nuclei must be taken\ninto account because they affect significantly the recoil spectra and event\nrates, regardless of whether the experiment probes DM via DM-nucleus or\nDM-electron interaction. To quantify this effect we present the publicly\navailable Dark Matter Simulation Code for Underground Scatterings (DaMaSCUS), a\nMonte Carlo simulator of DM trajectories through the Earth taking underground\nscatterings into account. Our simulation allows the precise calculation of the\ndensity and velocity distribution of dark matter at any detector of given depth\nand location on Earth. The simulation can also provide the accurate recoil\nspectrum in underground detectors as well as the phase and amplitude of the\ndiurnal modulation caused by this shadowing effect of the Earth, ultimately\nrelating the modulations expected in different detectors, which is important to\ndecisively conclude if a diurnal modulation is due to dark matter or an\nirrelevant background.\n",
"title": "DaMaSCUS: The Impact of Underground Scatterings on Direct Detection of Light Dark Matter"
}
| null | null |
[
"Physics"
] | null | true | null |
3502
| null |
Validated
| null | null |
null |
{
"abstract": " We propose a novel approach to allocating resources for expensive simulations\nof high fidelity models when used in a multifidelity framework. Allocation\ndecisions that distribute computational resources across several simulation\nmodels become extremely important in situations where only a small number of\nexpensive high fidelity simulations can be run. We identify this allocation\ndecision as a problem in optimal subset selection, and subsequently regularize\nthis problem so that solutions can be computed. Our regularized formulation\nyields a type of group lasso problem that has been studied in the literature to\naccomplish subset selection. Our numerical results compare performance of\nalgorithms that solve the group lasso problem for algorithmic allocation\nagainst a variety of other strategies, including those based on classical\nlinear algebraic pivoting routines and those derived from more modern machine\nlearning-based methods. We demonstrate on well known synthetic problems and\nmore difficult real-world simulations that this group lasso solution to the\nrelaxed optimal subset selection problem performs better than the alternatives.\n",
"title": "Allocation strategies for high fidelity models in the multifidelity regime"
}
| null | null |
[
"Computer Science"
] | null | true | null |
3503
| null |
Validated
| null | null |
null |
{
"abstract": " Networks provide a powerful formalism for modeling complex systems by using a\nmodel of pairwise interactions. But much of the structure within these systems\ninvolves interactions that take place among more than two nodes at once; for\nexample, communication within a group rather than person-to person,\ncollaboration among a team rather than a pair of coauthors, or biological\ninteraction between a set of molecules rather than just two. Such higher-order\ninteractions are ubiquitous, but their empirical study has received limited\nattention, and little is known about possible organizational principles of such\nstructures. Here we study the temporal evolution of 19 datasets with explicit\naccounting for higher-order interactions. We show that there is a rich variety\nof structure in our datasets but datasets from the same system types have\nconsistent patterns of higher-order structure. Furthermore, we find that tie\nstrength and edge density are competing positive indicators of higher-order\norganization, and these trends are consistent across interactions involving\ndiffering numbers of nodes. To systematically further the study of theories for\nsuch higher-order structures, we propose higher-order link prediction as a\nbenchmark problem to assess models and algorithms that predict higher-order\nstructure. We find a fundamental differences from traditional pairwise link\nprediction, with a greater role for local rather than long-range information in\npredicting the appearance of new interactions.\n",
"title": "Simplicial Closure and higher-order link prediction"
}
| null | null | null | null | true | null |
3504
| null |
Default
| null | null |
null |
{
"abstract": " A minimal constructed language (conlang) is useful for experiments and\ncomfortable for making tools. The Toki Pona (TP) conlang is minimal both in the\nvocabulary (with only 14 letters and 124 lemmas) and in the (about) 10 syntax\nrules. The language is useful for being a used and somewhat established minimal\nconlang with at least hundreds of fluent speakers. This article exposes current\nconcepts and resources for TP, and makes available Python (and Vim) scripted\nroutines for the analysis of the language, synthesis of texts, syntax\nhighlighting schemes, and the achievement of a preliminary TP Wordnet. Focus is\non the analysis of the basic vocabulary, as corpus analyses were found. The\nsynthesis is based on sentence templates, relates to context by keeping track\nof used words, and renders larger texts by using a fixed number of phonemes\n(e.g. for poems) and number of sentences, words and letters (e.g. for\nparagraphs). Syntax highlighting reflects morphosyntactic classes given in the\nofficial dictionary and different solutions are described and implemented in\nthe well-established Vim text editor. The tentative TP Wordnet is made\navailable in three patterns of relations between synsets and word lemmas. In\nsummary, this text holds potentially novel conceptualizations about, and tools\nand results in analyzing, synthesizing and syntax highlighting the TP language.\n",
"title": "Basic concepts and tools for the Toki Pona minimal and constructed language: description of the language and main issues; analysis of the vocabulary; text synthesis and syntax highlighting; Wordnet synsets"
}
| null | null |
[
"Computer Science"
] | null | true | null |
3505
| null |
Validated
| null | null |
null |
{
"abstract": " Nonparametric models are versatile, albeit computationally expensive, tool\nfor modeling mixture models. In this paper, we introduce spectral methods for\nthe two most popular nonparametric models: the Indian Buffet Process (IBP) and\nthe Hierarchical Dirichlet Process (HDP). We show that using spectral methods\nfor the inference of nonparametric models are computationally and statistically\nefficient. In particular, we derive the lower-order moments of the IBP and the\nHDP, propose spectral algorithms for both models, and provide reconstruction\nguarantees for the algorithms. For the HDP, we further show that applying\nhierarchical models on dataset with hierarchical structure, which can be solved\nwith the generalized spectral HDP, produces better solutions to that of flat\nmodels regarding likelihood performance.\n",
"title": "Spectral Methods for Nonparametric Models"
}
| null | null | null | null | true | null |
3506
| null |
Default
| null | null |
null |
{
"abstract": " Anomaly detection (AD) has garnered ample attention in security research, as\nsuch algorithms complement existing signature-based methods but promise\ndetection of never-before-seen attacks. Cyber operations manage a high volume\nof heterogeneous log data; hence, AD in such operations involves multiple\n(e.g., per IP, per data type) ensembles of detectors modeling heterogeneous\ncharacteristics (e.g., rate, size, type) often with adaptive online models\nproducing alerts in near real time. Because of high data volume, setting the\nthreshold for each detector in such a system is an essential yet underdeveloped\nconfiguration issue that, if slightly mistuned, can leave the system useless,\neither producing a myriad of alerts and flooding downstream systems, or giving\nnone. In this work, we build on the foundations of Ferragut et al. to provide a\nset of rigorous results for understanding the relationship between threshold\nvalues and alert quantities, and we propose an algorithm for setting the\nthreshold in practice. Specifically, we give an algorithm for setting the\nthreshold of multiple, heterogeneous, possibly dynamic detectors completely a\npriori, in principle. Indeed, if the underlying distribution of the incoming\ndata is known (closely estimated), the algorithm provides provably manageable\nthresholds. If the distribution is unknown (e.g., has changed over time) our\nanalysis reveals how the model distribution differs from the actual\ndistribution, indicating a period of model refitting is necessary. We provide\nempirical experiments showing the efficacy of the capability by regulating the\nalert rate of a system with $\\approx$2,500 adaptive detectors scoring over 1.5M\nevents in 5 hours. Further, we demonstrate on the real network data and\ndetection framework of Harshaw et al. the alternative case, showing how the\ninability to regulate alerts indicates the detection model is a bad fit to the\ndata.\n",
"title": "Setting the threshold for high throughput detectors: A mathematical approach for ensembles of dynamic, heterogeneous, probabilistic anomaly detectors"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
3507
| null |
Validated
| null | null |
null |
{
"abstract": " Time reversal is one of the most intriguing yet elusive wave phenomenon of\nmajor interest in different areas of classical and quantum physics. Time\nreversal requires in principle to flip the sign of the Hamiltonian of the\nsystem, leading to a revival of the initial state (Loschmidt echo). Here it is\nshown that Loschmidt echo of photons can be observed in an optical setting\nwithout resorting to reversal of the Hamiltonian. We consider photonic\npropagation in a binary waveguide lattice and show that, by exchanging the two\nsublattices after some propagation distance, a Loschmidt echo can be observed.\nExamples of Loschmidt echoes for single photon and NOON states are given in\none- and two-dimensional waveguide lattices.\n",
"title": "Photonic Loschmidt echo in binary waveguide lattices"
}
| null | null |
[
"Physics"
] | null | true | null |
3508
| null |
Validated
| null | null |
null |
{
"abstract": " We present a series of definitions and theorems demonstrating how to reduce\nthe requirements for proving system refinements ensuring containment of fair\nstuttering runs. A primary result of the work is the ability to reduce the\nrequisite proofs on runs of a system of interacting state machines to a set of\ndefinitions and checks on single steps of a small number of state machines\ncorresponding to the intuitive notions of freedom from starvation and deadlock.\nWe further refine the definitions to afford an efficient explicit-state\nchecking procedure in certain finite state cases. We demonstrate the proof\nreduction on versions of the Bakery Algorithm.\n",
"title": "Proof Reduction of Fair Stuttering Refinement of Asynchronous Systems and Applications"
}
| null | null |
[
"Computer Science"
] | null | true | null |
3509
| null |
Validated
| null | null |
null |
{
"abstract": " We study the global consequences in the halos of spiral galaxies of the\nsteady, axially symmetric, mean field dynamo. We use the classical theory but\nadd the possibility of using the velocity field components as parameters in\naddition to the helicity and diffusivity. The analysis is based on the simplest\nversion of the theory and uses scale-invariant solutions. The velocity field\n(subject to restrictions) is a scale invariant field in a `pattern' frame, in\nplace of a full dynamical theory. The `pattern frame' of reference may either\nbe the systemic frame or some rigidly rotating spiral pattern frame. One type\nof solution for the magnetic field yields off-axis, spirally wound, magnetic\nfield lines. These predict sign changes in the Faraday screen rotation measure\nin every quadrant of the halo of an edge-on galaxy. Such rotation measure\noscillations have been observed in the CHANG-ES survey.\n",
"title": "Steady Galactic Dynamos and Observational Consequences I: Halo Magnetic Fields"
}
| null | null | null | null | true | null |
3510
| null |
Default
| null | null |
null |
{
"abstract": " We propose new methods for Support Vector Machines (SVMs) using tree\narchitecture for multi-class classi- fication. In each node of the tree, we\nselect an appropriate binary classifier using entropy and generalization error\nestimation, then group the examples into positive and negative classes based on\nthe selected classi- fier and train a new classifier for use in the\nclassification phase. The proposed methods can work in time complexity between\nO(log2N) to O(N) where N is the number of classes. We compared the performance\nof our proposed methods to the traditional techniques on the UCI machine\nlearning repository using 10-fold cross-validation. The experimental results\nshow that our proposed methods are very useful for the problems that need fast\nclassification time or problems with a large number of classes as the proposed\nmethods run much faster than the traditional techniques but still provide\ncomparable accuracy.\n",
"title": "Efficient Decision Trees for Multi-class Support Vector Machines Using Entropy and Generalization Error Estimation"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
3511
| null |
Validated
| null | null |
null |
{
"abstract": " We show that each limiting semiclassical measure obtained from a sequence of\neigenfunctions of the Laplacian on a compact hyperbolic surface is supported on\nthe entire cosphere bundle. The key new ingredient for the proof is the fractal\nuncertainty principle, first formulated in [arXiv:1504.06589] and proved for\nporous sets in [arXiv:1612.09040].\n",
"title": "Semiclassical measures on hyperbolic surfaces have full support"
}
| null | null | null | null | true | null |
3512
| null |
Default
| null | null |
null |
{
"abstract": " Atmospheric moist available potential energy (MAPE) has been traditionally\ndefined as the potential energy of a moist atmosphere relative to that of the\nadiabatically sorted reference state defining a global potential energy\nminimum. Finding such a reference state was recently shown to be a linear\nassignment problem, and therefore exactly solvable. However, this is\ncomputationally extremely expensive, so there has been much interest in\ndeveloping heuristic methods for computing MAPE in practice. Comparisons of the\naccuracy of such approximate algorithms have so far been limited to a small\nnumber of test cases; this work provides an assessment of the algorithms'\nperformance across a wide range of atmospheric soundings, in two different\nlocations. We determine that the divide-and-conquer algorithm is the best\nsuited to practical application, but suffers from the previously overlooked\nshortcoming that it can produce a reference state with higher potential energy\nthan the actual state, resulting in a negative value of MAPE. Additionally, we\nshow that it is possible to construct an algorithm exploiting a theoretical\nexpression linking MAPE to Convective Available Potential Energy (CAPE)\npreviously derived by Kerry Emanuel. This approach has a similar accuracy to\nexisting approximate sorting algorithms, whilst providing greater insight into\nthe physical source of MAPE. In light of these results, we discuss how to make\nprogress towards constructing a satisfactory moist APE theory for the\natmosphere. We also outline a method for vectorising the adiabatic lifting of\nmoist air parcels, which increases the computational efficiency of algorithms\nfor calculating MAPE, and could be used for other applications such as\nconvection schemes.\n",
"title": "Assessment of algorithms for computing moist available potential energy"
}
| null | null | null | null | true | null |
3513
| null |
Default
| null | null |
null |
{
"abstract": " Many seminal results in Interactive Proofs (IPs) use algebraic techniques\nbased on low-degree polynomials, the study of which is pervasive in theoretical\ncomputer science. Unfortunately, known methods for endowing such proofs with\nzero knowledge guarantees do not retain this rich algebraic structure.\nIn this work, we develop algebraic techniques for obtaining zero knowledge\nvariants of proof protocols in a way that leverages and preserves their\nalgebraic structure. Our constructions achieve unconditional (perfect) zero\nknowledge in the Interactive Probabilistically Checkable Proof (IPCP) model of\nKalai and Raz [KR08] (the prover first sends a PCP oracle, then the prover and\nverifier engage in an Interactive Proof in which the verifier may query the\nPCP).\nOur main result is a zero knowledge variant of the sumcheck protocol [LFKN92]\nin the IPCP model. The sumcheck protocol is a key building block in many IPs,\nincluding the protocol for polynomial-space computation due to Shamir [Sha92],\nand the protocol for parallel computation due to Goldwasser, Kalai, and\nRothblum [GKR15]. A core component of our result is an algebraic commitment\nscheme, whose hiding property is guaranteed by algebraic query complexity lower\nbounds [AW09,JKRS09]. This commitment scheme can then be used to considerably\nstrengthen our previous work [BCFGRS16] that gives a sumcheck protocol with\nmuch weaker zero knowledge guarantees, itself using algebraic techniques based\non algorithms for polynomial identity testing [RS05,BW04].\nWe demonstrate the applicability of our techniques by deriving zero knowledge\nvariants of well-known protocols based on algebraic techniques, including the\nprotocols of Shamir and of Goldwasser, Kalai, and Rothblum, as well as the\nprotocol of Babai, Fortnow, and Lund [BFL91].\n",
"title": "A Zero Knowledge Sumcheck and its Applications"
}
| null | null | null | null | true | null |
3514
| null |
Default
| null | null |
null |
{
"abstract": " Quantum magnetic phases near the magnetic saturation of triangular-lattice\nantiferromagnets with XXZ anisotropy have been attracting renewed interest\nsince it has been suggested that a nontrivial coplanar phase, called the\n$\\pi$-coplanar or $\\Psi$ phase, could be stabilized by quantum effects in a\ncertain range of anisotropy parameter $J/J_z$ besides the well-known 0-coplanar\n(known also as $V$) and umbrella phases. Recently, Sellmann $et$ $al$. [Phys.\nRev. B {\\bf 91}, 081104(R) (2015)] claimed that the $\\pi$-coplanar phase is\nabsent for $S=1/2$ from an exact-diagonalization analysis in the sector of the\nHilbert space with only three down-spins (three magnons). We first reconsider\nand improve this analysis by taking into account several low-lying eigenvalues\nand the associated eigenstates as a function of $J/J_z$ and by sensibly\nincreasing the system sizes (up to 1296 spins). A careful identification\nanalysis shows that the lowest eigenstate is a chirally antisymmetric\ncombination of finite-size umbrella states for $J/J_z\\gtrsim 2.218$ while it\ncorresponds to a coplanar phase for $J/J_z\\lesssim 2.218$. However, we\ndemonstrate that the distinction between 0-coplanar and $\\pi$-coplanar phases\nin the latter region is fundamentally impossible from the symmetry-preserving\nfinite-size calculations with fixed magnon number.} Therefore, we also perform\na cluster mean-field plus scaling analysis for small spins $S\\leq 3/2$. The\nobtained results, together with the previous large-$S$ analysis, indicate that\nthe $\\pi$-coplanar phase exists for any $S$ except for the classical limit\n($S\\rightarrow \\infty$) and the existence range in $J/J_z$ is largest in the\nmost quantum case of $S=1/2$.\n",
"title": "Exact diagonalization and cluster mean-field study of triangular-lattice XXZ antiferromagnets near saturation"
}
| null | null | null | null | true | null |
3515
| null |
Default
| null | null |
null |
{
"abstract": " We consider the problem of finding local minimizers in non-convex and\nnon-smooth optimization. Under the assumption of strict saddle points, positive\nresults have been derived for first-order methods. We present the first known\nresults for the non-smooth case, which requires different analysis and a\ndifferent algorithm.\n",
"title": "Perturbed Proximal Descent to Escape Saddle Points for Non-convex and Non-smooth Objective Functions"
}
| null | null | null | null | true | null |
3516
| null |
Default
| null | null |
null |
{
"abstract": " Syntax errors are generally easy to fix for humans, but not for parsers, in\ngeneral, and LR parsers, in particular. Traditional 'panic mode' error\nrecovery, though easy to implement and applicable to any grammar, often leads\nto a cascading chain of errors that drown out the original. More advanced error\nrecovery techniques suffer less from this problem but have seen little\npractical use because their typical performance was seen as poor, their worst\ncase unbounded, and the repairs they reported arbitrary. In this paper we show\ntwo generic error recovery algorithms that fix all three problems. First, our\nalgorithms are the first to report the complete set of possible repair\nsequences for a given location, allowing programmers to select the one that\nbest fits their intention. Second, on a corpus of 200,000 real-world\nsyntactically invalid Java programs, we show that our best performing algorithm\nis able to repair 98.71% of files within a cut-off of 0.5s. Furthermore, we are\nalso able to use the complete set of repair sequences to reduce the cascading\nerror problem even further than previous approaches. Our best performing\nalgorithm reports 442,252.0 error locations in the corpus to the user, while\nthe panic mode algorithm reports 980,848.0 error locations: in other words, our\nalgorithms reduce the cascading error problem by well over half.\n",
"title": "Don't Panic! Better, Fewer, Syntax Errors for LR Parsers"
}
| null | null | null | null | true | null |
3517
| null |
Default
| null | null |
null |
{
"abstract": " Predicting the popularity of news article is a challenging task. Existing\nliterature mostly focused on article contents and polarity to predict\npopularity. However, existing research has not considered the users' preference\ntowards a particular article. Understanding users' preference is an important\naspect for predicting the popularity of news articles. Hence, we consider the\nsocial media data, from the Twitter platform, to address this research gap. In\nour proposed model, we have considered the users' involvement as well as the\nusers' reaction towards an article to predict the popularity of the article. In\nshort, we are predicting tomorrow's headline by probing today's Twitter\ndiscussion. We have considered 300 political news article from the New York\nPost, and our proposed approach has outperformed other baseline models.\n",
"title": "Predicting Tomorrow's Headline using Today's Twitter Deliberations"
}
| null | null | null | null | true | null |
3518
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we give a negative answer to a problem presented by\nBharanedhar and Ponnusamy (Rocky Mountain J. Math. 44: 753--777, 2014)\nconcerning univalency of a class of harmonic mappings. More precisely, we show\nthat for all values of the involved parameter, this class contains a\nnon-univalent function. Moreover, several results on a new subclass of\nclose-to-convex harmonic mappings, which is motivated by work of Ponnusamy and\nSairam Kaliraj (Mediterr. J. Math. 12: 647--665, 2015), are obtained.\n",
"title": "On a problem of Bharanedhar and Ponnusamy involving planar harmonic mappings"
}
| null | null |
[
"Mathematics"
] | null | true | null |
3519
| null |
Validated
| null | null |
null |
{
"abstract": " Forecasts of mortality provide vital information about future populations,\nwith implications for pension and health-care policy as well as for decisions\nmade by private companies about life insurance and annuity pricing. Stochastic\nmortality forecasts allow the uncertainty in mortality predictions to be taken\ninto consideration when making policy decisions and setting product prices.\nLonger lifespans imply that forecasts of mortality at ages 90 and above will\nbecome more important in such calculations.\nThis paper presents a Bayesian approach to the forecasting of mortality that\njointly estimates a Generalised Additive Model (GAM) for mortality for the\nmajority of the age-range and a parametric model for older ages where the data\nare sparser. The GAM allows smooth components to be estimated for age, cohort\nand age-specific improvement rates, together with a non-smoothed period effect.\nForecasts for the United Kingdom are produced using data from the Human\nMortality Database spanning the period 1961-2013. A metric that approximates\npredictive accuracy under Leave-One-Out cross-validation is used to estimate\nweights for the `stacking' of forecasts with different points of transition\nbetween the GAM and parametric elements.\nMortality for males and females are estimated separately at first, but a\njoint model allows the asymptotic limit of mortality at old ages to be shared\nbetween sexes, and furthermore provides for forecasts accounting for\ncorrelations in period innovations. The joint and single sex model forecasts\nestimated using data from 1961-2003 are compared against observed data from\n2004-2013 to facilitate model assessment.\n",
"title": "Projecting UK Mortality using Bayesian Generalised Additive Models"
}
| null | null | null | null | true | null |
3520
| null |
Default
| null | null |
null |
{
"abstract": " Machine learning is usually defined in behaviourist terms, where external\nvalidation is the primary mechanism of learning. In this paper, I argue for a\nmore holistic interpretation in which finding more probable, efficient and\nabstract representations is as central to learning as performance. In other\nwords, machine learning should be extended with strategies to reason over its\nown learning process, leading to so-called meta-cognitive machine learning. As\nsuch, the de facto definition of machine learning should be reformulated in\nthese intrinsically multi-objective terms, taking into account not only the\ntask performance but also internal learning objectives. To this end, we suggest\na \"model entropy function\" to be defined that quantifies the efficiency of the\ninternal learning processes. It is conjured that the minimization of this model\nentropy leads to concept formation. Besides philosophical aspects, some initial\nillustrations are included to support the claims.\n",
"title": "The Case for Meta-Cognitive Machine Learning: On Model Entropy and Concept Formation in Deep Learning"
}
| null | null | null | null | true | null |
3521
| null |
Default
| null | null |
null |
{
"abstract": " Acoustic wave attenuation due to vibrational and rotational molecular\nrelaxation, under simplifying assumptions of near-thermodynamic equilibrium and\nabsence of molecular dissociations, can be accounted for by specifying a bulk\nviscosity coefficient $\\mu_B$. In this paper, we propose a simple\nfrequency-dependent bulk viscosity model which, under such assumptions,\naccurately captures wave attenuation rates from infrasonic to ultrasonic\nfrequencies in Navier--Stokes and lattice Boltzmann simulations. The proposed\nmodel can be extended to any gas mixture for which molecular relaxation\ntimescales and attenuation measurements are available. The performance of the\nmodel is assessed for air by varying the base temperature, pressure, relative\nhumidity $h_r$, and acoustic frequency. Since the vibrational relaxation\ntimescales of oxygen and nitrogen are a function of humidity, for certain\nfrequencies an intermediate value of $h_r$ can be found which maximizes\n$\\mu_B$. The contribution to bulk viscosity due to rotational relaxation is\nverified to be a function of temperature, confirming recent findings in the\nliterature. While $\\mu_B$ decreases with higher frequencies, its effects on\nwave attenuation become more significant, as shown via a dimensionless\nanalysis. The proposed bulk viscosity model is designed for frequency-domain\nlinear acoustic formulations but is also extensible to time-domain simulations\nof narrow-band frequency content flows.\n",
"title": "Bulk viscosity model for near-equilibrium acoustic wave attenuation"
}
| null | null |
[
"Physics"
] | null | true | null |
3522
| null |
Validated
| null | null |
null |
{
"abstract": " A Lagrangian fluctuation-dissipation relation has been derived in a previous\nwork to describe the dissipation rate of advected scalars, both passive and\nactive, in wall-bounded flows. We apply this relation here to develop a\nLagrangian description of thermal dissipation in turbulent Rayleigh-Bénard\nconvection in a right-cylindrical cell of arbitrary cross-section, with either\nimposed temperature difference or imposed heat-flux at the top and bottom\nwalls. We obtain an exact relation between the steady-state thermal dissipation\nrate and the time for passive tracer particles released at the top or bottom\nwall to mix to their final uniform value near those walls. We show that an\n\"ultimate regime\" with the Nusselt-number scaling predicted by Spiegel (1971)\nor, with a log-correction, by Kraichnan (1962) will occur at high Rayleigh\nnumbers, unless this near-wall mixing time is asymptotically much longer than\nthe free-fall time, or almost the large-scale circulation time. We suggest a\nnew criterion for an ultimate regime in terms of transition to turbulence of a\nthermal \"mixing zone\", which is much wider than the standard thermal boundary\nlayer. Kraichnan-Spiegel scaling may, however, not hold if the intensity and\nvolume of thermal plumes decrease sufficiently rapidly with increasing Rayleigh\nnumber. To help resolve this issue, we suggest a program to measure the\nnear-wall mixing time, which we argue is accessible both by laboratory\nexperiment and by numerical simulation.\n",
"title": "A Lagrangian fluctuation-dissipation relation for scalar turbulence, III. Turbulent Rayleigh-Bénard convection"
}
| null | null | null | null | true | null |
3523
| null |
Default
| null | null |
null |
{
"abstract": " This paper examines the limit properties of information criteria (such as\nAIC, BIC, HQIC) for distinguishing between the unit root model and the various\nkinds of explosive models. The explosive models include the local-to-unit-root\nmodel, the mildly explosive model and the regular explosive model. Initial\nconditions with different order of magnitude are considered. Both the OLS\nestimator and the indirect inference estimator are studied. It is found that\nBIC and HQIC, but not AIC, consistently select the unit root model when data\ncome from the unit root model. When data come from the local-to-unit-root\nmodel, both BIC and HQIC select the wrong model with probability approaching 1\nwhile AIC has a positive probability of selecting the right model in the limit.\nWhen data come from the regular explosive model or from the mildly explosive\nmodel in the form of $1+n^{\\alpha }/n$ with $\\alpha \\in (0,1)$, all three\ninformation criteria consistently select the true model. Indirect inference\nestimation can increase or decrease the probability for information criteria to\nselect the right model asymptotically relative to OLS, depending on the\ninformation criteria and the true model. Simulation results confirm our\nasymptotic results in finite sample.\n",
"title": "Model Selection for Explosive Models"
}
| null | null | null | null | true | null |
3524
| null |
Default
| null | null |
null |
{
"abstract": " Density estimation is a fundamental problem in statistical learning. This\nproblem is especially challenging for complex high-dimensional data due to the\ncurse of dimensionality. A promising solution to this problem is given here in\nan inference-free hierarchical framework that is built on score matching. We\nrevisit the Bayesian interpretation of the score function and the Parzen score\nmatching, and construct a multilayer perceptron with a scalable objective for\nlearning the energy (i.e. the unnormalized log-density), which is then\noptimized with stochastic gradient descent. In addition, the resulting deep\nenergy estimator network (DEEN) is designed as products of experts. We present\nthe utility of DEEN in learning the energy, the score function, and in\nsingle-step denoising experiments for synthetic and high-dimensional data. We\nalso diagnose stability problems in the direct estimation of the score function\nthat had been observed for denoising autoencoders.\n",
"title": "Deep Energy Estimator Networks"
}
| null | null |
[
"Statistics"
] | null | true | null |
3525
| null |
Validated
| null | null |
null |
{
"abstract": " Existing strategies for finite-armed stochastic bandits mostly depend on a\nparameter of scale that must be known in advance. Sometimes this is in the form\nof a bound on the payoffs, or the knowledge of a variance or subgaussian\nparameter. The notable exceptions are the analysis of Gaussian bandits with\nunknown mean and variance by Cowan and Katehakis [2015] and of uniform\ndistributions with unknown support [Cowan and Katehakis, 2015]. The results\nderived in these specialised cases are generalised here to the non-parametric\nsetup, where the learner knows only a bound on the kurtosis of the noise, which\nis a scale free measure of the extremity of outliers.\n",
"title": "A Scale Free Algorithm for Stochastic Bandits with Bounded Kurtosis"
}
| null | null | null | null | true | null |
3526
| null |
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| null | null |
null |
{
"abstract": " Asynchronous parallel computing and sparse recovery are two areas that have\nreceived recent interest. Asynchronous algorithms are often studied to solve\noptimization problems where the cost function takes the form $\\sum_{i=1}^M\nf_i(x)$, with a common assumption that each $f_i$ is sparse; that is, each\n$f_i$ acts only on a small number of components of $x\\in\\mathbb{R}^n$. Sparse\nrecovery problems, such as compressed sensing, can be formulated as\noptimization problems, however, the cost functions $f_i$ are dense with respect\nto the components of $x$, and instead the signal $x$ is assumed to be sparse,\nmeaning that it has only $s$ non-zeros where $s\\ll n$. Here we address how one\nmay use an asynchronous parallel architecture when the cost functions $f_i$ are\nnot sparse in $x$, but rather the signal $x$ is sparse. We propose an\nasynchronous parallel approach to sparse recovery via a stochastic greedy\nalgorithm, where multiple processors asynchronously update a vector in shared\nmemory containing information on the estimated signal support. We include\nnumerical simulations that illustrate the potential benefits of our proposed\nasynchronous method.\n",
"title": "An Asynchronous Parallel Approach to Sparse Recovery"
}
| null | null | null | null | true | null |
3527
| null |
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| null | null |
null |
{
"abstract": " State-of-the-art neural networks are vulnerable to adversarial examples; they\ncan easily misclassify inputs that are imperceptibly different than their\ntraining and test data. In this work, we establish that the use of\ncross-entropy loss function and the low-rank features of the training data have\nresponsibility for the existence of these inputs. Based on this observation, we\nsuggest that addressing adversarial examples requires rethinking the use of\ncross-entropy loss function and looking for an alternative that is more suited\nfor minimization with low-rank features. In this direction, we present a\ntraining scheme called differential training, which uses a loss function\ndefined on the differences between the features of points from opposite\nclasses. We show that differential training can ensure a large margin between\nthe decision boundary of the neural network and the points in the training\ndataset. This larger margin increases the amount of perturbation needed to flip\nthe prediction of the classifier and makes it harder to find an adversarial\nexample with small perturbations. We test differential training on a binary\nclassification task with CIFAR-10 dataset and demonstrate that it radically\nreduces the ratio of images for which an adversarial example could be found --\nnot only in the training dataset, but in the test dataset as well.\n",
"title": "Cross-Entropy Loss and Low-Rank Features Have Responsibility for Adversarial Examples"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
3528
| null |
Validated
| null | null |
null |
{
"abstract": " One of the challenges in testing gravity with cosmology is the vast freedom\nopened when extending General Relativity. For linear perturbations, one\nsolution consists in using the Effective Field Theory of Dark Energy (EFT of\nDE). Even then, the theory space is described in terms of a handful of free\nfunctions of time. This needs to be reduced to a finite number of parameters to\nbe practical for cosmological surveys. We explore in this article how well\nsimple parametrizations, with a small number of parameters, can fit observables\ncomputed from complex theories. Imposing the stability of linear perturbations\nappreciably reduces the theory space we explore. We find that observables are\nnot extremely sensitive to short time-scale variations and that simple, smooth\nparametrizations are usually sufficient to describe this theory space. Using\nthe Bayesian Information Criterion, we find that using two parameters for each\nfunction (an amplitude and a power law index) is preferred over complex models\nfor 86% of our theory space.\n",
"title": "Parametrizing modified gravity for cosmological surveys"
}
| null | null |
[
"Physics"
] | null | true | null |
3529
| null |
Validated
| null | null |
null |
{
"abstract": " Let $A$ be a free hyperplane arrangement. In 1989, Ziegler showed that the\nrestriction $A''$ of $A$ to any hyperplane endowed with the natural\nmultiplicity is then a free multiarrangement. We initiate a study of the\nstronger freeness property of inductive freeness for these canonical free\nmultiarrangements and investigate them for the underlying class of reflection\narrangements.\nMore precisely, let $A = A(W)$ be the reflection arrangement of a complex\nreflection group $W$. By work of Terao, each such reflection arrangement is\nfree. Thus so is Ziegler's canonical multiplicity on the restriction $A''$ of\n$A$ to a hyperplane. We show that the latter is inductively free as a\nmultiarrangement if and only if $A''$ itself is inductively free.\n",
"title": "Inductive Freeness of Ziegler's Canonical Multiderivations for Reflection Arrangements"
}
| null | null | null | null | true | null |
3530
| null |
Default
| null | null |
null |
{
"abstract": " The integration of III-V on silicon is still a hot topic as it will open up a\nway to co-integrate Si CMOS logic with photonic vices. To reach this aim,\nseveral hurdles should be solved, and more particularly the generation of\nantiphase boundaries (APBs) at the III-V/Si(001) interface. Density functional\ntheory (DFT) has been used to demonstrate the existence of a double-layer steps\non nominal Si(001) which is formed during annealing under proper hydrogen\nchemical potential. This phenomenon could be explained by the formation of\ndimer vacancy lines which could be responsible for the preferential and\nselective etching of one type of step leading to the double step surface\ncreation. To check this hypothesis, different experiments have been carried in\nan industrial 300 mm MOCVD where the total pressure during the anneal step of\nSi(001) surface has been varied. Under optimized conditions, an APBs-free GaAs\nlayer was grown on a nominal Si(001) surface paving the way for III-V\nintegration on silicon industrial platform.\n",
"title": "Toward III-V/Si co-integration by controlling biatomic steps on hydrogenated Si(001)"
}
| null | null | null | null | true | null |
3531
| null |
Default
| null | null |
null |
{
"abstract": " This volume contains a selection of the papers presented at the XVI Jornadas\nsobre Programación y Lenguajes (PROLE 2016), held at Salamanca, Spain, during\nSeptember 14th-15th, 2016. Previous editions of the workshop were held in\nSantander (2015), Cádiz (2014), Madrid (2013), Almería (2012), A Coruña\n(2011), València (2010), San Sebastián (2009), Gijón (2008), Zaragoza\n(2007), Sitges (2006), Granada (2005), Málaga (2004), Alicante (2003), El\nEscorial (2002), and Almagro (2001). Programming languages provide a conceptual\nframework which is necessary for the development, analysis, optimization and\nunderstanding of programs and programming tasks. The aim of the PROLE series of\nconferences (PROLE stems from PROgramación y LEnguajes) is to serve as a\nmeeting point for Spanish research groups which develop their work in the area\nof programming and programming languages. The organization of this series of\nevents aims at fostering the exchange of ideas, experiences and results among\nthese groups. Promoting further collaboration is also one of its main goals.\n",
"title": "Proceedings XVI Jornadas sobre Programación y Lenguajes"
}
| null | null |
[
"Computer Science"
] | null | true | null |
3532
| null |
Validated
| null | null |
null |
{
"abstract": " We investigate the asymptotic behavior of sequences generated by the proximal\npoint algorithm for convex functions in complete geodesic spaces with curvature\nbounded above. Using the notion of resolvents of such functions, which was\nrecently introduced by the authors, we show the existence of minimizers of\nconvex functions under the boundedness assumptions on such sequences as well as\nthe convergence of such sequences to minimizers of given functions.\n",
"title": "The proximal point algorithm in geodesic spaces with curvature bounded above"
}
| null | null |
[
"Mathematics"
] | null | true | null |
3533
| null |
Validated
| null | null |
null |
{
"abstract": " Canards are special solutions to ordinary differential equations that follow\ninvariant repelling slow manifolds for long time intervals. In realistic\nbiophysical single cell models, canards are responsible for several complex\nneural rhythms observed experimentally, but their existence and role in\nspatially-extended systems is largely unexplored. We describe a novel type of\ncoherent structure in which a spatial pattern displays temporal canard\nbehaviour. Using interfacial dynamics and geometric singular perturbation\ntheory, we classify spatio-temporal canards and give conditions for the\nexistence of folded-saddle and folded-node canards. We find that\nspatio-temporal canards are robust to changes in the synaptic connectivity and\nfiring rate. The theory correctly predicts the existence of spatio-temporal\ncanards with octahedral symmetries in a neural field model posed on the unit\nsphere.\n",
"title": "Spatio-temporal canards in neural field equations"
}
| null | null | null | null | true | null |
3534
| null |
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| null | null |
null |
{
"abstract": " In this paper we study selected argument forms involving counterfactuals and\nindicative conditionals under uncertainty. We selected argument forms to\nexplore whether people with an Eastern cultural background reason differently\nabout conditionals compared to Westerners, because of the differences in the\nlocation of negations. In a 2x2 between-participants design, 63 Japanese\nuniversity students were allocated to four groups, crossing indicative\nconditionals and counterfactuals, and each presented in two random task orders.\nThe data show close agreement between the responses of Easterners and\nWesterners. The modal responses provide strong support for the hypothesis that\nconditional probability is the best predictor for counterfactuals and\nindicative conditionals. Finally, the grand majority of the responses are\nprobabilistically coherent, which endorses the psychological plausibility of\nchoosing coherence-based probability logic as a rationality framework for\npsychological reasoning research.\n",
"title": "Counterfactuals, indicative conditionals, and negation under uncertainty: Are there cross-cultural differences?"
}
| null | null | null | null | true | null |
3535
| null |
Default
| null | null |
null |
{
"abstract": " We propose a DTCWT ScatterNet Convolutional Neural Network (DTSCNN) formed by\nreplacing the first few layers of a CNN network with a parametric log based\nDTCWT ScatterNet. The ScatterNet extracts edge based invariant representations\nthat are used by the later layers of the CNN to learn high-level features. This\nimproves the training of the network as the later layers can learn more complex\npatterns from the start of learning because the edge representations are\nalready present. The efficient learning of the DTSCNN network is demonstrated\non CIFAR-10 and Caltech-101 datasets. The generic nature of the ScatterNet\nfront-end is shown by an equivalent performance to pre-trained CNN front-ends.\nA comparison with the state-of-the-art on CIFAR-10 and Caltech-101 datasets is\nalso presented.\n",
"title": "Efficient Convolutional Network Learning using Parametric Log based Dual-Tree Wavelet ScatterNet"
}
| null | null | null | null | true | null |
3536
| null |
Default
| null | null |
null |
{
"abstract": " Let $\\tau(n)$ be the number of divisors of $n$. We give an elementary proof\nof the fact that $$ \\sum_{n\\le x} \\tau(n)^r =xC_{r} (\\log x)^{2^r-1}+O(x(\\log\nx)^{2^r-2}), $$ for any integer $r\\ge 2$. Here, $$ C_{r}=\\frac{1}{(2^r-1)!}\n\\prod_{p\\ge 2}\\left( \\left(1-\\frac{1}{p}\\right)^{2^r} \\left(\\sum_{\\alpha\\ge 0}\n\\frac{(\\alpha+1)^r}{p^{\\alpha}}\\right)\\right). $$\n",
"title": "The $r$th moment of the divisor function: an elementary approach"
}
| null | null | null | null | true | null |
3537
| null |
Default
| null | null |
null |
{
"abstract": " In this study, we present the preliminary test, Stein-type and positive part\nLiu estimators in the linear models when the parameter vector\n$\\boldsymbol{\\beta}$ is partitioned into two parts, namely, the main effects\n$\\boldsymbol{\\beta}_1$ and the nuisance effects $\\boldsymbol{\\beta}_2$ such\nthat $\\boldsymbol{\\beta}=\\left(\\boldsymbol{\\beta}_1, \\boldsymbol{\\beta}_2\n\\right)$. We consider the case that a priori known or suspected set of the\nexplanatory variables do not contribute to predict the response so that a\nsub-model may be enough for this purpose. Thus, the main interest is to\nestimate $\\boldsymbol{\\beta}_1$ when $\\boldsymbol{\\beta}_2$ is close to zero.\nTherefore, we conduct a Monte Carlo simulation study to evaluate the relative\nefficiency of the suggested estimators, where we demonstrate the superiority of\nthe proposed estimators.\n",
"title": "Liu-type Shrinkage Estimations in Linear Models"
}
| null | null |
[
"Mathematics",
"Statistics"
] | null | true | null |
3538
| null |
Validated
| null | null |
null |
{
"abstract": " We present an efficient coresets-based neural network compression algorithm\nthat provably sparsifies the parameters of a trained fully-connected neural\nnetwork in a manner that approximately preserves the network's output. Our\napproach is based on an importance sampling scheme that judiciously defines a\nsampling distribution over the neural network parameters, and as a result,\nretains parameters of high importance while discarding redundant ones. We\nleverage a novel, empirical notion of sensitivity and extend traditional\ncoreset constructions to the application of compressing parameters. Our\ntheoretical analysis establishes guarantees on the size and accuracy of the\nresulting compressed neural network and gives rise to new generalization bounds\nthat may provide novel insights on the generalization properties of neural\nnetworks. We demonstrate the practical effectiveness of our algorithm on a\nvariety of neural network configurations and real-world data sets.\n",
"title": "Data-Dependent Coresets for Compressing Neural Networks with Applications to Generalization Bounds"
}
| null | null | null | null | true | null |
3539
| null |
Default
| null | null |
null |
{
"abstract": " Active Galactic Nuclei (AGN) are energetic astrophysical sources powered by\naccretion onto supermassive black holes in galaxies, and present unique\nobservational signatures that cover the full electromagnetic spectrum over more\nthan twenty orders of magnitude in frequency. The rich phenomenology of AGN has\nresulted in a large number of different \"flavours\" in the literature that now\ncomprise a complex and confusing AGN \"zoo\". It is increasingly clear that these\nclassifications are only partially related to intrinsic differences between\nAGN, and primarily reflect variations in a relatively small number of\nastrophysical parameters as well the method by which each class of AGN is\nselected. Taken together, observations in different electromagnetic bands as\nwell as variations over time provide complementary windows on the physics of\ndifferent sub-structures in the AGN. In this review, we present an overview of\nAGN multi-wavelength properties with the aim of painting their \"big picture\"\nthrough observations in each electromagnetic band from radio to gamma-rays as\nwell as AGN variability. We address what we can learn from each observational\nmethod, the impact of selection effects, the physics behind the emission at\neach wavelength, and the potential for future studies. To conclude we use these\nobservations to piece together the basic architecture of AGN, discuss our\ncurrent understanding of unification models, and highlight some open questions\nthat present opportunities for future observational and theoretical progress.\n",
"title": "Active Galactic Nuclei: what's in a name?"
}
| null | null | null | null | true | null |
3540
| null |
Default
| null | null |
null |
{
"abstract": " A recent result characterizes the fully order reversing operators acting on\nthe class of lower semicontinuous proper convex functions in a real Banach\nspace as certain linear deformations of the Legendre-Fenchel transform.\nMotivated by the Hilbert space version of this result and by the well-known\nresult saying that this convex conjugation transform has a unique fixed point\n(namely, the normalized energy function), we investigate the fixed point\nequation in which the involved operator is fully order reversing and acts on\nthe above-mentioned class of functions. It turns out that this nonlinear\nequation is very sensitive to the involved parameters and can have no solution,\na unique solution, or several (possibly infinitely many) ones. Our analysis\nyields a few by-products, such as results related to positive definite\noperators, and to functional equations and inclusions involving monotone\noperators.\n",
"title": "Fixed points of Legendre-Fenchel type transforms"
}
| null | null | null | null | true | null |
3541
| null |
Default
| null | null |
null |
{
"abstract": " The optimization of composition and processing to obtain materials that\nexhibit desirable characteristics has historically relied on a combination of\nscientist intuition, trial and error, and luck. We propose a methodology that\ncan accelerate this process by fitting data-driven models to experimental data\nas it is collected to suggest which experiment should be performed next. This\nmethodology can guide the scientist to test the most promising candidates\nearlier, and can supplement scientific intuition and knowledge with data-driven\ninsights. A key strength of the proposed framework is that it scales to\nhigh-dimensional parameter spaces, as are typical in materials discovery\napplications. Importantly, the data-driven models incorporate uncertainty\nanalysis, so that new experiments are proposed based on a combination of\nexploring high-uncertainty candidates and exploiting high-performing regions of\nparameter space. Over four materials science test cases, our methodology led to\nthe optimal candidate being found with three times fewer required measurements\nthan random guessing on average.\n",
"title": "High-Dimensional Materials and Process Optimization using Data-driven Experimental Design with Well-Calibrated Uncertainty Estimates"
}
| null | null | null | null | true | null |
3542
| null |
Default
| null | null |
null |
{
"abstract": " Consider the noncrossing set partitions of an $n$-element set which either do\nnot contain the block $\\{n-1,n\\}$, or which do not contain the singleton block\n$\\{n\\}$ whenever $1$ and $n-1$ are in the same block. In this article we study\nthe subposet of the noncrossing partition lattice induced by these elements,\nand show that it is a supersolvable lattice, and therefore lexicographically\nshellable. We give a combinatorial model for the NBB bases of this lattice and\nderive an explicit formula for the value of its Möbius function between least\nand greatest element. This work is motivated by a recent article by M. Bruce,\nM. Dougherty, M. Hlavacek, R. Kudo, and I. Nicolas, in which they introduce a\nsubposet of the noncrossing partition lattice that is determined by parking\nfunctions with certain forbidden entries. In particular, they conjecture that\nthe resulting poset always has a contractible order complex. We prove this\nconjecture by embedding their poset into ours, and showing that it inherits the\nlexicographic shellability.\n",
"title": "Two Posets of Noncrossing Partitions Coming From Undesired Parking Spaces"
}
| null | null | null | null | true | null |
3543
| null |
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| null | null |
null |
{
"abstract": " In this paper, we focus on finding clusters in partially categorized data\nsets. We propose a semi-supervised version of Gaussian mixture model, called\nC3L, which retrieves natural subgroups of given categories. In contrast to\nother semi-supervised models, C3L is parametrized by user-defined leakage\nlevel, which controls maximal inconsistency between initial categorization and\nresulting clustering. Our method can be implemented as a module in practical\nexpert systems to detect clusters, which combine expert knowledge with true\ndistribution of data. Moreover, it can be used for improving the results of\nless flexible clustering techniques, such as projection pursuit clustering. The\npaper presents extensive theoretical analysis of the model and fast algorithm\nfor its efficient optimization. Experimental results show that C3L finds high\nquality clustering model, which can be applied in discovering meaningful groups\nin partially classified data.\n",
"title": "Semi-supervised model-based clustering with controlled clusters leakage"
}
| null | null | null | null | true | null |
3544
| null |
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| null | null |
null |
{
"abstract": " Large bundles of myelinated axons, called white matter, anatomically connect\ndisparate brain regions together and compose the structural core of the human\nconnectome. We recently proposed a method of measuring the local integrity\nalong the length of each white matter fascicle, termed the local connectome. If\ncommunication efficiency is fundamentally constrained by the integrity along\nthe entire length of a white matter bundle, then variability in the functional\ndynamics of brain networks should be associated with variability in the local\nconnectome. We test this prediction using two statistical approaches that are\ncapable of handling the high dimensionality of data. First, by performing\nstatistical inference on distance-based correlations, we show that similarity\nin the local connectome between individuals is significantly correlated with\nsimilarity in their patterns of functional connectivity. Second, by employing\nvariable selection using sparse canonical correlation analysis and\ncross-validation, we show that segments of the local connectome are predictive\nof certain patterns of functional brain dynamics. These results are consistent\nwith the hypothesis that structural variability along axon bundles constrains\ncommunication between disparate brain regions.\n",
"title": "Local White Matter Architecture Defines Functional Brain Dynamics"
}
| null | null | null | null | true | null |
3545
| null |
Default
| null | null |
null |
{
"abstract": " We present a strengthening of the lemma on the lower bound of the slice rank\nby Tao (2016) motivated by the Croot-Lev-Pach-Ellenberg-Gijswijt bound on cap\nsets (2017, 2017). The Croot-Lev-Pach-Ellenberg-Gijswijt method and the lemma\nof Tao are based on the fact that the rank of a diagonal matrix is equal to the\nnumber of non-zero diagonal entries. Our lemma is based on the rank of\nupper-triangular matrices. This stronger lemma allows us to prove the following\nextension of the Ellenberg-Gijswijt result (2017). A tricolored ordered\nsum-free set in $\\mathbb F_p^n$ is a collection\n$\\{(a_i,b_i,c_i):i=1,2,\\ldots,m\\}$ of ordered triples in $(\\mathbb F_p^n )^3$\nsuch that $a_i+b_i+c_i=0$ and if $a_i+b_j+c_k=0$, then $i\\le j\\le k$. By using\nthe new lemma, we present an upper bound on the size of a tricolored ordered\nsum-free set in $\\mathbb F_p^n$.\n",
"title": "An upper bound on tricolored ordered sum-free sets"
}
| null | null | null | null | true | null |
3546
| null |
Default
| null | null |
null |
{
"abstract": " Functional Analysis of Variance (FANOVA) from Hilbert-valued correlated data\nwith spatial rectangular or circular supports is analyzed, when Dirichlet\nconditions are assumed on the boundary. Specifically, a Hilbert-valued fixed\neffect model with error term defined from an Autoregressive Hilbertian process\nof order one (ARH(1) process) is considered, extending the formulation given in\nRuiz-Medina (2016). A new statistical test is also derived to contrast the\nsignificance of the functional fixed effect parameters. The Dirichlet\nconditions established at the boundary affect the dependence range of the\ncorrelated error term. While the rate of convergence to zero of the eigenvalues\nof the covariance kernels, characterizing the Gaussian functional error\ncomponents, directly affects the stability of the generalized least-squares\nparameter estimation problem. A simulation study and a real-data application\nrelated to fMRI analysis are undertaken to illustrate the performance of the\nparameter estimator and statistical test derived.\n",
"title": "The effect of the spatial domain in FANOVA models with ARH(1) error term"
}
| null | null | null | null | true | null |
3547
| null |
Default
| null | null |
null |
{
"abstract": " We present a method that gets as input an audio of violin or piano playing,\nand outputs a video of skeleton predictions which are further used to animate\nan avatar. The key idea is to create an animation of an avatar that moves their\nhands similarly to how a pianist or violinist would do, just from audio. Aiming\nfor a fully detailed correct arms and fingers motion is a goal, however, it's\nnot clear if body movement can be predicted from music at all. In this paper,\nwe present the first result that shows that natural body dynamics can be\npredicted at all. We built an LSTM network that is trained on violin and piano\nrecital videos uploaded to the Internet. The predicted points are applied onto\na rigged avatar to create the animation.\n",
"title": "Audio to Body Dynamics"
}
| null | null | null | null | true | null |
3548
| null |
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| null | null |
null |
{
"abstract": " Identifying causal relationships from observational time series data is a key\nproblem in disciplines such as climate science or neuroscience, where\nexperiments are often not possible. Data-driven causal inference is challenging\nsince datasets are often high-dimensional and nonlinear with limited sample\nsizes. Here we introduce a novel method that flexibly combines linear or\nnonlinear conditional independence tests with a causal discovery algorithm that\nallows to reconstruct causal networks from large-scale time series datasets. We\nvalidate the method on a well-established climatic teleconnection connecting\nthe tropical Pacific with extra-tropical temperatures and using large-scale\nsynthetic datasets mimicking the typical properties of real data. The\nexperiments demonstrate that our method outperforms alternative techniques in\ndetection power from small to large-scale datasets and opens up entirely new\npossibilities to discover causal networks from time series across a range of\nresearch fields.\n",
"title": "Detecting causal associations in large nonlinear time series datasets"
}
| null | null | null | null | true | null |
3549
| null |
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| null | null |
null |
{
"abstract": " Telepresence is a necessity for present time as we can't reach everywhere and\nalso it is useful in saving human life at dangerous places. A robot, which\ncould be controlled from a distant location, can solve these problems. This\ncould be via communication waves or networking methods. Also controlling should\nbe in real time and smooth so that it can actuate on every minor signal in an\neffective way. This paper discusses a method to control a robot over the\nnetwork from a distant location. The robot was controlled by hand gestures\nwhich were captured by the live camera. A DSP board TMS320DM642EVM was used to\nimplement image pre-processing and fastening the whole system. PCA was used for\ngesture classification and robot actuation was done according to predefined\nprocedures. Classification information was sent over the network in the\nexperiment. This method is robust and could be used to control any kind of\nrobot over distance.\n",
"title": "Controlling a remotely located Robot using Hand Gestures in real time: A DSP implementation"
}
| null | null | null | null | true | null |
3550
| null |
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| null | null |
null |
{
"abstract": " In the industry of video content providers such as VOD and IPTV, predicting\nthe popularity of video contents in advance is critical not only from a\nmarketing perspective but also from a network optimization perspective. By\npredicting whether the content will be successful or not in advance, the\ncontent file, which is large, is efficiently deployed in the proper service\nproviding server, leading to network cost optimization. Many previous studies\nhave done view count prediction research to do this. However, the studies have\nbeen making predictions based on historical view count data from users. In this\ncase, the contents had been published to the users and already deployed on a\nservice server. These approaches make possible to efficiently deploy a content\nalready published but are impossible to use for a content that is not be\npublished. To address the problems, this research proposes a hybrid machine\nlearning approach to the classification model for the popularity prediction of\nnewly video contents which is not published. In this paper, we create a new\nvariable based on the related content of the specific content and divide entire\ndataset by the characteristics of the contents. Next, the prediction is\nperformed using XGBoosting and deep neural net based model according to the\ndata characteristics of the cluster. Our model uses metadata for contents for\nprediction, so we use categorical embedding techniques to solve the sparsity of\ncategorical variables and make them learn efficiently for the deep neural net\nmodel. As well, we use the FTRL-proximal algorithm to solve the problem of the\nview-count volatility of video content. We achieve overall better performance\nthan the previous standalone method with a dataset from one of the top\nstreaming service company.\n",
"title": "Hybrid Machine Learning Approach to Popularity Prediction of Newly Released Contents for Online Video Streaming Service"
}
| null | null | null | null | true | null |
3551
| null |
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| null | null |
null |
{
"abstract": " We prove the following continuous analogue of Vaught's Two-Cardinal Theorem:\nif for some $\\kappa>\\lambda\\geq \\aleph_0$, a continuous theory $T$ has a model\nwith density character $\\kappa$ which has a definable subset of density\ncharacter $\\lambda$, then $T$ has a model with density character $\\aleph_1$\nwhich has a separable definable subset. We also show that if we assume that $T$\nis $\\omega$-stable, then if $T$ has a model of density character $\\aleph_1$\nwith a separable definable set, then for any uncountable $\\kappa$ we can find a\nmodel of $T$ with density character $\\kappa$ which has a separable definable\nsubset. In order to prove this, we develop an approximate notion of\nquasi-minimality for the continuous setting. We apply these results to show a\ncontinuous version of the forward direction of the Baldwin-Lachlan\ncharacterization of uncountable categoricity: if a continuous theory $T$ is\nuncountably categorical, then $T$ is $\\omega$-stable and has no Vaughtian\npairs.\n",
"title": "Vaught's Two-Cardinal Theorem and Quasi-Minimality in Continuous Logic"
}
| null | null | null | null | true | null |
3552
| null |
Default
| null | null |
null |
{
"abstract": " We present a novel method to measure precisely the relative spectral response\nof the fluorescence telescopes of the Pierre Auger Observatory. We used a\nportable light source based on a xenon flasher and a monochromator to measure\nthe relative spectral efficiencies of eight telescopes in steps of 5 nm from\n280 nm to 440 nm. Each point in a scan had approximately 2 nm FWHM out of the\nmonochromator. Different sets of telescopes in the observatory have different\noptical components, and the eight telescopes measured represent two each of the\nfour combinations of components represented in the observatory. We made an\nend-to-end measurement of the response from different combinations of optical\ncomponents, and the monochromator setup allowed for more precise and complete\nmeasurements than our previous multi-wavelength calibrations. We find an\noverall uncertainty in the calibration of the spectral response of most of the\ntelescopes of 1.5% for all wavelengths; the six oldest telescopes have larger\noverall uncertainties of about 2.2%. We also report changes in physics\nmeasureables due to the change in calibration, which are generally small.\n",
"title": "Spectral Calibration of the Fluorescence Telescopes of the Pierre Auger Observatory"
}
| null | null | null | null | true | null |
3553
| null |
Default
| null | null |
null |
{
"abstract": " We show that Müntz spaces, as subspaces of $C[0,1]$, contain\nasymptotically isometric copies of $c_0$ and that their dual spaces are\noctahedral.\n",
"title": "Two properties of Müntz spaces"
}
| null | null | null | null | true | null |
3554
| null |
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| null | null |
null |
{
"abstract": " This article describes a sequence of rational functions which converges\nlocally uniformly to the zeta function. The numerators (and denominators) of\nthese rational functions can be expressed as characteristic polynomials of\nmatrices that are on the face of it very simple. As a consequence, the Riemann\nhypothesis can be restated as what looks like a rather conventional spectral\nproblem but which is related to the one found by Connes in his analysis of the\nzeta function. However the point here is that the rational approximations look\nto be susceptible of quantitative estimation.\n",
"title": "Rational approximations to the zeta function"
}
| null | null | null | null | true | null |
3555
| null |
Default
| null | null |
null |
{
"abstract": " We analyze new far-ultraviolet spectra of 13 quasars from the z~0.2 COS-Halos\nsurvey that cover the HI Lyman limit of 14 circumgalactic medium (CGM) systems.\nThese data yield precise estimates or more constraining limits than previous\nCOS-Halos measurements on the HI column densities NHI. We then apply a\nMonte-Carlo Markov Chain approach on 32 systems from COS-Halos to estimate the\nmetallicity of the cool (T~10^4K) CGM gas that gives rise to low-ionization\nstate metal lines, under the assumption of photoionization equilibrium with the\nextragalactic UV background. The principle results are: (1) the CGM of field L*\ngalaxies exhibits a declining HI surface density with impact parameter Rperp\n(at >99.5%$ confidence), (2) the transmission of ionizing radiation through CGM\ngas alone is 70+/-7%; (3) the metallicity distribution function of the cool CGM\nis unimodal with a median of 1/3 Z_Sun and a 95% interval from ~1/50 Z_Sun to\nover 3x solar. The incidence of metal poor (<1/100 Z_Sun) gas is low, implying\nany such gas discovered along quasar sightlines is typically unrelated to L*\ngalaxies; (4) we find an unexpected increase in gas metallicity with declining\nNHI (at >99.9% confidence) and, therefore, also with increasing Rperp. The high\nmetallicity at large radii implies early enrichment; (5) A non-parametric\nestimate of the cool CGM gas mass is M_CGM_cool = 9.2 +/- 4.3 10^10 Msun, which\ntogether with new mass estimates for the hot CGM may resolve the galactic\nmissing baryons problem. Future analyses of halo gas should focus on the\nunderlying astrophysics governing the CGM, rather than processes that simply\nexpel the medium from the halo.\n",
"title": "The COS-Halos Survey: Metallicities in the Low-Redshift Circumgalactic Medium"
}
| null | null | null | null | true | null |
3556
| null |
Default
| null | null |
null |
{
"abstract": " Quaternionic tori are defined as quotients of the skew field $\\mathbb{H}$ of\nquaternions by rank-4 lattices. Using slice regular functions, these tori are\nendowed with natural structures of quaternionic manifolds (in fact quaternionic\ncurves), and a fundamental region in a $12$-dimensional real subspace is then\nconstructed to classify them up to biregular diffeomorphisms. The points of the\nmoduli space correspond to suitable \\emph{special} bases of rank-4 lattices,\nwhich are studied with respect to the action of the group $GL(4, \\mathbb{Z})$,\nand up to biregular diffeomeorphisms. All tori with a non trivial group of\nbiregular automorphisms - and all possible groups of their biregular\nautomorphisms - are then identified, and recognized to correspond to five\ndifferent subsets of boundary points of the moduli space.\n",
"title": "On Quaternionic Tori and their Moduli Spaces"
}
| null | null | null | null | true | null |
3557
| null |
Default
| null | null |
null |
{
"abstract": " A Danish computer, GIER, from 1961 played a vital role in the development of\na new method for astrometric measurement. This method, photon counting\nastrometry, ultimately led to two satellites with a significant role in the\nmodern revolution of astronomy. A GIER was installed at the Hamburg Observatory\nin 1964 where it was used to implement the entirely new method for the\nmeasurement of stellar positions by means of a meridian circle, then the\nfundamental instrument of astrometry. An expedition to Perth in Western\nAustralia with the instrument and the computer was a success. This method was\nalso implemented in space in the first ever astrometric satellite Hipparcos\nlaunched by ESA in 1989. The Hipparcos results published in 1997 revolutionized\nastrometry with an impact in all branches of astronomy from the solar system\nand stellar structure to cosmic distances and the dynamics of the Milky Way. In\nturn, the results paved the way for a successor, the one million times more\npowerful Gaia astrometry satellite launched by ESA in 2013. Preparations for a\nGaia successor in twenty years are making progress.\n",
"title": "GIER: A Danish computer from 1961 with a role in the modern revolution of astronomy"
}
| null | null | null | null | true | null |
3558
| null |
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| null | null |
null |
{
"abstract": " Several recent papers investigate Active Learning (AL) for mitigating the\ndata dependence of deep learning for natural language processing. However, the\napplicability of AL to real-world problems remains an open question. While in\nsupervised learning, practitioners can try many different methods, evaluating\neach against a validation set before selecting a model, AL affords no such\nluxury. Over the course of one AL run, an agent annotates its dataset\nexhausting its labeling budget. Thus, given a new task, an active learner has\nno opportunity to compare models and acquisition functions. This paper provides\na large scale empirical study of deep active learning, addressing multiple\ntasks and, for each, multiple datasets, multiple models, and a full suite of\nacquisition functions. We find that across all settings, Bayesian active\nlearning by disagreement, using uncertainty estimates provided either by\nDropout or Bayes-by Backprop significantly improves over i.i.d. baselines and\nusually outperforms classic uncertainty sampling.\n",
"title": "Deep Bayesian Active Learning for Natural Language Processing: Results of a Large-Scale Empirical Study"
}
| null | null |
[
"Statistics"
] | null | true | null |
3559
| null |
Validated
| null | null |
null |
{
"abstract": " Here we write in a unified fashion (using \"R(P, Q, D)\") the random coding\nexponents in channel coding and lossy source coding. We derive their explicit\nforms and show, that, for a given random codebook distribution Q, the channel\ndecoding error exponent can be viewed as an encoding success exponent in lossy\nsource coding, and the channel correct-decoding exponent can be viewed as an\nencoding failure exponent in lossy source coding. We then extend the channel\nexponents to arbitrary D, which corresponds for D > 0 to erasure decoding and\nfor D < 0 to list decoding. For comparison, we also derive the exact random\ncoding exponent for Forney's optimum tradeoff decoder.\n",
"title": "Analogy and duality between random channel coding and lossy source coding"
}
| null | null | null | null | true | null |
3560
| null |
Default
| null | null |
null |
{
"abstract": " A rising topic in computational journalism is how to enhance the diversity in\nnews served to subscribers to foster exploration behavior in news reading.\nDespite the success of preference learning in personalized news recommendation,\ntheir over-exploitation causes filter bubble that isolates readers from\nopposing viewpoints and hurts long-term user experiences with lack of\nserendipity. Since news providers can recommend neither opposite nor\ndiversified opinions if unpopularity of these articles is surely predicted,\nthey can only bet on the articles whose forecasts of click-through rate involve\nhigh variability (risks) or high estimation errors (uncertainties). We propose\na novel Bayesian model of uncertainty-aware scoring and ranking for news\narticles. The Bayesian binary classifier models probability of success (defined\nas a news click) as a Beta-distributed random variable conditional on a vector\nof the context (user features, article features, and other contextual\nfeatures). The posterior of the contextual coefficients can be computed\nefficiently using a low-rank version of Laplace's method via thin Singular\nValue Decomposition. Efficiencies in personalized targeting of exceptional\narticles, which are chosen by each subscriber in test period, are evaluated on\nreal-world news datasets. The proposed estimator slightly outperformed existing\ntraining and scoring algorithms, in terms of efficiency in identifying\nsuccessful outliers.\n",
"title": "Towards Bursting Filter Bubble via Contextual Risks and Uncertainties"
}
| null | null | null | null | true | null |
3561
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we introduce certain $n$-th order nonlinear Loewy factorizable\nalgebraic ordinary differential equations for the first time and study the\ngrowth of their meromorphic solutions in terms of the Nevanlinna characteristic\nfunction. It is shown that for generic cases all their meromorphic solutions\nare elliptic functions or their degenerations and hence their order of growth\nare at most two. Moreover, for the second order factorizable algebraic ODEs,\nall the meromorphic solutions of them (except for one case) are found\nexplicitly. This allows us to show that a conjecture proposed by Hayman in 1996\nholds for these second order ODEs.\n",
"title": "Nonlinear Loewy Factorizable Algebraic ODEs and Hayman's Conjecture"
}
| null | null | null | null | true | null |
3562
| null |
Default
| null | null |
null |
{
"abstract": " As robots begin to cohabit with humans in semi-structured environments, the\nneed arises to understand instructions involving rich variability---for\ninstance, learning to ground symbols in the physical world. Realistically, this\ntask must cope with small datasets consisting of a particular users' contextual\nassignment of meaning to terms. We present a method for processing a raw stream\nof cross-modal input---i.e., linguistic instructions, visual perception of a\nscene and a concurrent trace of 3D eye tracking fixations---to produce the\nsegmentation of objects with a correspondent association to high-level\nconcepts. To test our framework we present experiments in a table-top object\nmanipulation scenario. Our results show our model learns the user's notion of\ncolour and shape from a small number of physical demonstrations, generalising\nto identifying physical referents for novel combinations of the words.\n",
"title": "Grounding Symbols in Multi-Modal Instructions"
}
| null | null | null | null | true | null |
3563
| null |
Default
| null | null |
null |
{
"abstract": " We pursue a novel morphometric analysis to detect sources in very-high-energy\ngamma-ray counts maps by structural deviations from the background noise.\nBecause the Minkowski functionals from integral geometry quantify the shape of\nthe counts map itself, the morphometric analysis includes unbiased structure\ninformation without prior knowledge about the source. Their distribution\nprovides access to intricate geometric information about the background. We\ncombine techniques from stochastic geometry and statistical physics to\ndetermine the joint distribution of all Minkowski functionals. We achieve an\naccurate characterization of the background structure for large scan windows\n(with up to $15\\times15$ pixels), where the number of microstates varies over\nup to 64 orders of magnitude. Moreover, in a detailed simulation study, we\nconfirm the statistical significance of features in the background noise and\ndiscuss how to correct for trial effects. We also present a local correction of\ndetector effects that can considerably enhance the sensitivity of the analysis.\nIn the third paper of this series, we will use the here derived refined\nstructure characterization for a more sensitive data analysis that can detect\nformerly undetected sources.\n",
"title": "Morphometric analysis in gamma-ray astronomy using Minkowski functionals: II. Joint structure quantification"
}
| null | null | null | null | true | null |
3564
| null |
Default
| null | null |
null |
{
"abstract": " This work develops a tracking system based on an event-based camera. A\nbioinspired filtering algorithm to reduce noise and transmitted data while\nkeeping the main features at the scene is implemented in FPGA which also serves\nas a network node. POWERLINK IEEE 61158 industrial network is used to\ncommunicate the FPGA with a controller connected to a self-developed two axis\nservo-controlled robot. The FPGA includes the network protocol to integrate the\nevent-based camera as any other existing network node. The inverse kinematics\nfor the robot is included in the controller. In addition, another network node\nis used to control pneumatic valves blowing the ball at different speed and\ntrajectories. To complete the system and provide a comparison, a traditional\nframe-based camera is also connected to the controller. The imaging data for\nthe tracking system are obtained either from the event-based or frame-based\ncamera. Results show that the robot can accurately follow the ball using fast\nimage recognition, with the intrinsic advantages of the event-based system\n(size, price, power). This works shows how the development of new equipment and\nalgorithms can be efficiently integrated in an industrial system, merging\ncommercial industrial equipment with the new devices so that new technologies\ncan rapidly enter into the industrial field.\n",
"title": "An Event-based Fast Movement Detection Algorithm for a Positioning Robot Using POWERLINK Communication"
}
| null | null | null | null | true | null |
3565
| null |
Default
| null | null |
null |
{
"abstract": " We present an efficient score statistic, called the $\\textsf{S}^3 \\textsf{T}$\nstatistic, to detect the emergence of a spatially and temporally correlated\nsignal from either fixed-sample or sequential data. The signal may cause a men\nshift and/or a change in the covariance structure. The score statistic can\ncapture both spatial and temporal structures of the change and hence is\nparticularly powerful in detecting weak signals. The score statistic is\ncomputationally efficient and statistically powerful. Our main theoretical\ncontribution are accurate analytical approximations on the false alarm rate of\nthe detection procedures, which can be used to calibrate the threshold\nanalytically. Numerical experiments on simulated and real data demonstrate the\ngood performance of our procedure for solar flame detection and water quality\nmonitoring.\n",
"title": "$\\textsf{S}^3T$: An Efficient Score-Statistic for Spatio-Temporal Surveillance"
}
| null | null | null | null | true | null |
3566
| null |
Default
| null | null |
null |
{
"abstract": " The increase in network connectivity has also resulted in several\nhigh-profile attacks on cyber-physical systems. An attacker that manages to\naccess a local network could remotely affect control performance by tampering\nwith sensor measurements delivered to the controller. Recent results have shown\nthat with network-based attacks, such as Man-in-the-Middle attacks, the\nattacker can introduce an unbounded state estimation error if measurements from\na suitable subset of sensors contain false data when delivered to the\ncontroller. While these attacks can be addressed with the standard\ncryptographic tools that ensure data integrity, their continuous use would\nintroduce significant communication and computation overhead. Consequently, we\nstudy effects of intermittent data integrity guarantees on system performance\nunder stealthy attacks. We consider linear estimators equipped with a general\ntype of residual-based intrusion detectors (including $\\chi^2$ and SPRT\ndetectors), and show that even when integrity of sensor measurements is\nenforced only intermittently, the attack impact is significantly limited;\nspecifically, the state estimation error is bounded or the attacker cannot\nremain stealthy. Furthermore, we present methods to: (1) evaluate the effects\nof any given integrity enforcement policy in terms of reachable\nstate-estimation errors for any type of stealthy attacks, and (2) design an\nenforcement policy that provides the desired estimation error guarantees under\nattack. Finally, on three automotive case studies we show that even with less\nthan 10% of authenticated messages we can ensure satisfiable control\nperformance in the presence of attacks.\n",
"title": "Relaxing Integrity Requirements for Attack-Resilient Cyber-Physical Systems"
}
| null | null | null | null | true | null |
3567
| null |
Default
| null | null |
null |
{
"abstract": " With the increasing popularity of smart devices, rumors with multimedia\ncontent become more and more common on social networks. The multimedia\ninformation usually makes rumors look more convincing. Therefore, finding an\nautomatic approach to verify rumors with multimedia content is a pressing task.\nPrevious rumor verification research only utilizes multimedia as input\nfeatures. We propose not to use the multimedia content but to find external\ninformation in other news platforms pivoting on it. We introduce a new features\nset, cross-lingual cross-platform features that leverage the semantic\nsimilarity between the rumors and the external information. When implemented,\nmachine learning methods utilizing such features achieved the state-of-the-art\nrumor verification results.\n",
"title": "Cross-Lingual Cross-Platform Rumor Verification Pivoting on Multimedia Content"
}
| null | null | null | null | true | null |
3568
| null |
Default
| null | null |
null |
{
"abstract": " The Ricci iteration is a discrete analogue of the Ricci flow. According to\nPerelman, the Ricci flow converges to a Kahler-Einstein metric whenever one\nexists, and it has been conjectured that the Ricci iteration should behave\nsimilarly. This article confirms this conjecture. As a special case, this gives\na new method of uniformization of the Riemann sphere.\n",
"title": "Convergence of the Kähler-Ricci iteration"
}
| null | null | null | null | true | null |
3569
| null |
Default
| null | null |
null |
{
"abstract": " RNA sequencing allows one to study allelic imbalance of gene expression,\nwhich may be due to genetic factors or genomic imprinting. It is desirable to\nmodel both genetic and parent-of-origin effects simultaneously to avoid\nconfounding and to improve the power to detect either effect. In a study of\nexperimental cross, separation of genetic and parent-of-origin effects can be\nachieved by studying reciprocal cross of two inbred strains. In contrast, this\ntask is much more challenging for an outbred population such as human\npopulation. To address this challenge, we propose a new framework to combine\nexperimental strategies and novel statistical methods. Specifically, we propose\nto collect genotype data from family trios as well as RNA-seq data from the\nchildren of family trios. We have developed a new statistical method to\nestimate both genetic and parent-of-origin effects from such data sets. We\ndemonstrated this approach by studying 30 trios of HapMap samples. Our results\nsupport some of previous finding of imprinted genes and also recover new\ncandidate imprinted genes.\n",
"title": "Joint estimation of genetic and parent-of-origin effects using RNA-seq data from human"
}
| null | null |
[
"Statistics"
] | null | true | null |
3570
| null |
Validated
| null | null |
null |
{
"abstract": " Bound-to-Bound Data Collaboration (B2BDC) provides a natural framework for\naddressing both forward and inverse uncertainty quantification problems. In\nthis approach, QOI (quantity of interest) models are constrained by related\nexperimental observations with interval uncertainty. A collection of such\nmodels and observations is termed a dataset and carves out a feasible region in\nthe parameter space. If a dataset has a nonempty feasible set, it is said to be\nconsistent. In real-world applications, it is often the case that collections\nof experiments and observations are inconsistent. Revealing the source of this\ninconsistency, i.e., identifying which models and/or observations are\nproblematic, is essential before a dataset can be used for prediction. To\naddress this issue, we introduce a constraint relaxation-based approach,\nentitled the vector consistency measure, for investigating datasets with\nnumerous sources of inconsistency. The benefits of this vector consistency\nmeasure over a previous method of consistency analysis are demonstrated in two\nrealistic gas combustion examples.\n",
"title": "Consistency Analysis for Massively Inconsistent Datasets in Bound-to-Bound Data Collaboration"
}
| null | null |
[
"Computer Science",
"Mathematics"
] | null | true | null |
3571
| null |
Validated
| null | null |
null |
{
"abstract": " Hydra is a header-only, templated and C++11-compliant framework designed to\nperform the typical bottleneck calculations found in common HEP data analyses\non massively parallel platforms. The framework is implemented on top of the\nC++11 Standard Library and a variadic version of the Thrust library and is\ndesigned to run on Linux systems, using OpenMP, CUDA and TBB enabled devices.\nThis contribution summarizes the main features of Hydra. A basic description of\nthe overall design, functionality and user interface is provided, along with\nsome code examples and measurements of performance.\n",
"title": "Hydra: a C++11 framework for data analysis in massively parallel platforms"
}
| null | null |
[
"Computer Science",
"Physics"
] | null | true | null |
3572
| null |
Validated
| null | null |
null |
{
"abstract": " Deep learning is the state-of-the-art in fields such as visual object\nrecognition and speech recognition. This learning uses a large number of\nlayers, huge number of units, and connections. Therefore, overfitting is a\nserious problem. To avoid this problem, dropout learning is proposed. Dropout\nlearning neglects some inputs and hidden units in the learning process with a\nprobability, p, and then, the neglected inputs and hidden units are combined\nwith the learned network to express the final output. We find that the process\nof combining the neglected hidden units with the learned network can be\nregarded as ensemble learning, so we analyze dropout learning from this point\nof view.\n",
"title": "Analysis of dropout learning regarded as ensemble learning"
}
| null | null | null | null | true | null |
3573
| null |
Default
| null | null |
null |
{
"abstract": " Mounting evidence connects the biomechanical properties of tissues to the\ndevelopment of eye diseases such as keratoconus, a common disease in which the\ncornea thins and bulges into a conical shape. However, measuring biomechanical\nchanges in vivo with sufficient sensitivity for disease detection has proved\nchallenging. Here, we present a first large-scale study (~200 subjects,\nincluding normal and keratoconus patients) using Brillouin light-scattering\nmicroscopy to measure longitudinal modulus in corneal tissues with high\nsensitivity and spatial resolution. Our results in vivo provide evidence of\nbiomechanical inhomogeneity at the onset of keratoconus and suggest that\nbiomechanical asymmetry between the left and right eyes may presage disease\ndevelopment. We additionally measure the stiffening effect of corneal\ncrosslinking treatment in vivo for the first time. Our results demonstrate the\npromise of Brillouin microscopy for diagnosis and treatment of keratoconus, and\npotentially other diseases.\n",
"title": "Spatially-resolved Brillouin spectroscopy reveals biomechanical changes in early ectatic corneal disease and post-crosslinking in vivo"
}
| null | null | null | null | true | null |
3574
| null |
Default
| null | null |
null |
{
"abstract": " Message Passing Interface (MPI) is the standard paradigm of programming in\nhigh performance computing. MPI programming takes significant effort, and is\nerror-prone. Thus, effective tools for analyzing MPI programs are much needed.\nOn the other hand, analyzing MPI programs itself is challenging because of\nnon-determinism caused by program inputs and non-deterministic operations.\nExisting approaches for analyzing MPI programs either do not handle inputs or\nfail to support programs with mixed blocking and non-blocking operations.\nThis paper presents MPI symbolic verifier (MPI-SV), the first symbolic\nexecution based tool for verifying MPI programs having both blocking and\nnon-blocking operations. To ensure soundness, we propose a blockingdriven\nmatching algorithm to safely handle non-deterministic operations, and a method\nto soundly and completely model the equivalent behavior of a program execution\npath. The models of MPI program paths are generated on-the-fly during symbolic\nexecution, and verified w.r.t. the expected properties by model checking. To\nimprove scalability, MPI-SV uses the results of model checking to prune\nredundant paths.\nWe have implemented MPI-SV and evaluated it on the verification of deadlock\nfreedom for 108 real-world MPI tasks. The pure symbolic execution based\ntechnique can successfully verify 61 out of the 108 tasks (56%) within one\nhour, while in comparison, MPI-SV can verify 94 tasks (87%), a 31% improvement.\nOn average, MPI-SV also achieves 7.25X speedup on verifying deadlock freedom\nand 2.64X speedup on finding deadlocks. These experimental results are\npromising, and demonstrate MPI-SV's effectiveness and efficiency.\n",
"title": "Combining Symbolic Execution and Model Checking to Verify MPI Programs"
}
| null | null | null | null | true | null |
3575
| null |
Default
| null | null |
null |
{
"abstract": " The modified Cholesky decomposition is commonly used for inverse covariance\nmatrix estimation given a specified order of random variables. However, the\norder of variables is often not available or cannot be pre-determined. Hence,\nwe propose a novel estimator to address the variable order issue in the\nmodified Cholesky decomposition to estimate the sparse inverse covariance\nmatrix. The key idea is to effectively combine a set of estimates obtained from\nmultiple permutations of variable orders, and to efficiently encourage the\nsparse structure for the resultant estimate by the use of thresholding\ntechnique on the combined Cholesky factor matrix. The consistent property of\nthe proposed estimate is established under some weak regularity conditions.\nSimulation studies show the superior performance of the proposed method in\ncomparison with several existing approaches. We also apply the proposed method\ninto the linear discriminant analysis for analyzing real-data examples for\nclassification.\n",
"title": "An Improved Modified Cholesky Decomposition Method for Inverse Covariance Matrix Estimation"
}
| null | null |
[
"Statistics"
] | null | true | null |
3576
| null |
Validated
| null | null |
null |
{
"abstract": " This is a comment on Reinhart's \"Review of Self-Exciting Spatio-Temporal\nPoint Processes and Their Applications\" (arXiv:1708.02647v1). I contribute some\nexperiences from modelling the spread of infectious diseases. Furthermore, I\ntry to complement the review with regard to the availability of software for\nthe described models, which I think is essential in \"paving the way for new\nuses\".\n",
"title": "Self-exciting Point Processes: Infections and Implementations"
}
| null | null | null | null | true | null |
3577
| null |
Default
| null | null |
null |
{
"abstract": " We have compared the magnetic, transport, galvanomagnetic and specific heat\nproperties of CeNiC$_2$, PrNiC$_2$ and NdNiC$_2$ to study the interplay between\ncharge density waves and magnetism in these compounds. The negative\nmagnetoresistance in NdNiC$_2$ is discussed in terms of the partial destruction\nof charge density waves and an irreversible phase transition stabilized by the\nfield induced ferromagnetic transformation is reported. For PrNiC$_2$ we\ndemonstrate that the magnetic field initially weakens the CDW state, due to the\nZeeman splitting of conduction bands. However, the Fermi surface nesting is\nenhanced at a temperature related to the magnetic anomaly.\n",
"title": "Magnetism and charge density waves in RNiC$_2$ (R = Ce, Pr, Nd)"
}
| null | null |
[
"Physics"
] | null | true | null |
3578
| null |
Validated
| null | null |
null |
{
"abstract": " In this paper we present conjoined constraints on several cosmological models\nfrom the expansion history $H(z)$ and cosmic growth $f\\sigma_8(z)$. The models\nwe study include the CPL $w_0w_a$ parametrization, the Holographic Dark Energy\n(HDE) model, the Time varying vacuum ($\\Lambda_t$CDM) model, the Dvali,\nGabadadze and Porrati (DGP) and Finsler-Randers (FRDE) models, a power law\n$f(T)$ model and finally the Hu-Sawicki $f(R)$ model. In all cases we perform a\nsimultaneous fit to the SnIa, CMB, BAO, $H(z)$ and growth data, while also\nfollowing the conjoined visualization of $H(z)$ and $f\\sigma_8(z)$ as in Linder\n(2017). Furthermore, we introduce the Figure of Merit (FoM) in the\n$H(z)-f\\sigma_8(z)$ parameter space as a way to constrain models that jointly\nfit both probes well. We use both the latest $H(z)$ and $f\\sigma_8(z)$ data,\nbut also LSST-like mocks with $1\\%$ measurements and we find that the conjoined\nmethod of constraining the expansion history and cosmic growth simultaneously\nis able not only to place stringent constraints on these parameters but also to\nprovide an easy visual way to discriminate cosmological models. Finally, we\nconfirm the existence of a tension between the growth rate and Planck CMB data\nand we find that the FoM in the conjoined parameter space of\n$H(z)-f\\sigma_8(z)$ can be used to discriminate between the $\\Lambda$CDM model\nand certain classes of modified gravity models, namely the DGP and $f(T)$.\n",
"title": "Conjoined constraints on modified gravity from the expansion history and cosmic growth"
}
| null | null |
[
"Physics"
] | null | true | null |
3579
| null |
Validated
| null | null |
null |
{
"abstract": " The dynamics of a circular thin vortex ring and a sphere moving along the\nsymmetry axis of the ring in an inviscid incompressible fluid is studied on the\nbasis of Euler's equations of motion. The equations of motion for position and\nradius of the vortex ring and those for position and velocity of the sphere are\ncoupled by hydrodynamic interactions. The equations are cast in Hamiltonian\nform, from which it is seen that total energy and momentum are conserved. The\nfour Hamiltonian equations of motion are solved numerically for a variety of\ninitial conditions.\n",
"title": "Coaxial collisions of a vortex ring and a sphere in an inviscid incompressible fluid"
}
| null | null |
[
"Physics"
] | null | true | null |
3580
| null |
Validated
| null | null |
null |
{
"abstract": " Measurements of $\\sigma_8$ from large scale structure observations show a\ndiscordance with the extrapolated $\\sigma_8$ from Planck CMB parameters using\n$\\Lambda$CDM cosmology. Similar discordance is found in the value of $H_0$ and\n$\\Omega_m$. In this paper, we show that the presence of viscosity in cold dark\nmatter, shear or bulk or combination of both, can remove the above mentioned\nconflicts simultaneously. This indicates that the data from Planck CMB\nobservation and different LSS observations prefer small but non-zero amount of\nviscosity in cold dark matter fluid.\n",
"title": "Cosmic viscosity as a remedy for tension between PLANCK and LSS data"
}
| null | null | null | null | true | null |
3581
| null |
Default
| null | null |
null |
{
"abstract": " We invoke a Gaussian mixture model (GMM) to jointly analyse two traditional\nemission-line classification schemes of galaxy ionization sources: the\nBaldwin-Phillips-Terlevich (BPT) and $\\rm W_{H\\alpha}$ vs. [NII]/H$\\alpha$\n(WHAN) diagrams, using spectroscopic data from the Sloan Digital Sky Survey\nData Release 7 and SEAGal/STARLIGHT datasets. We apply a GMM to empirically\ndefine classes of galaxies in a three-dimensional space spanned by the $\\log$\n[OIII]/H$\\beta$, $\\log$ [NII]/H$\\alpha$, and $\\log$ EW(H${\\alpha}$), optical\nparameters. The best-fit GMM based on several statistical criteria suggests a\nsolution around four Gaussian components (GCs), which are capable to explain up\nto 97 per cent of the data variance. Using elements of information theory, we\ncompare each GC to their respective astronomical counterpart. GC1 and GC4 are\nassociated with star-forming galaxies, suggesting the need to define a new\nstarburst subgroup. GC2 is associated with BPT's Active Galaxy Nuclei (AGN)\nclass and WHAN's weak AGN class. GC3 is associated with BPT's composite class\nand WHAN's strong AGN class. Conversely, there is no statistical evidence --\nbased on four GCs -- for the existence of a Seyfert/LINER dichotomy in our\nsample. Notwithstanding, the inclusion of an additional GC5 unravels it. The\nGC5 appears associated to the LINER and Passive galaxies on the BPT and WHAN\ndiagrams respectively. Subtleties aside, we demonstrate the potential of our\nmethodology to recover/unravel different objects inside the wilderness of\nastronomical datasets, without lacking the ability to convey physically\ninterpretable results. The probabilistic classifications from the GMM analysis\nare publicly available within the COINtoolbox\n(this https URL\\_Catalogue/).\n",
"title": "A probabilistic approach to emission-line galaxy classification"
}
| null | null | null | null | true | null |
3582
| null |
Default
| null | null |
null |
{
"abstract": " We present a quantum repeater scheme that is based on individual erbium and\neuropium ions. Erbium ions are attractive because they emit photons at\ntelecommunication wavelength, while europium ions offer exceptional spin\ncoherence for long-term storage. Entanglement between distant erbium ions is\ncreated by photon detection. The photon emission rate of each erbium ion is\nenhanced by a microcavity with high Purcell factor, as has recently been\ndemonstrated. Entanglement is then transferred to nearby europium ions for\nstorage. Gate operations between nearby ions are performed using dynamically\ncontrolled electric-dipole coupling. These gate operations allow entanglement\nswapping to be employed in order to extend the distance over which entanglement\nis distributed. The deterministic character of the gate operations allows\nimproved entanglement distribution rates in comparison to atomic ensemble-based\nprotocols. We also propose an approach that utilizes multiplexing in order to\nenhance the entanglement distribution rate.\n",
"title": "Quantum repeaters with individual rare-earth ions at telecommunication wavelengths"
}
| null | null | null | null | true | null |
3583
| null |
Default
| null | null |
null |
{
"abstract": " In recent years, the logic of questions and dependencies has been\ninvestigated in the closely related frameworks of inquisitive logic and\ndependence logic. These investigations have assumed classical logic as the\nbackground logic of statements, and added formulas expressing questions and\ndependencies to this classical core. In this paper, we broaden the scope of\nthese investigations by studying questions and dependency in the context of\nintuitionistic logic. We propose an intuitionistic team semantics, where teams\nare embedded within intuitionistic Kripke models. The associated logic is a\nconservative extension of intuitionistic logic with questions and dependence\nformulas. We establish a number of results about this logic, including a normal\nform result, a completeness result, and translations to classical inquisitive\nlogic and modal dependence logic.\n",
"title": "Questions and dependency in intuitionistic logic"
}
| null | null | null | null | true | null |
3584
| null |
Default
| null | null |
null |
{
"abstract": " There is a strong demand for precise means for the comparison of logics in\nterms of expressiveness both from theoretical and from application areas. The\naim of this paper is to propose a sufficiently general and reasonable formal\ncriterion for expressiveness, so as to apply not only to model-theoretic\nlogics, but also to Tarskian and proof-theoretic logics. For model-theoretic\nlogics there is a standard framework of relative expressiveness, based on the\ncapacity of characterizing structures, and a straightforward formal criterion\nissuing from it. The problem is that it only allows the comparison of those\nlogics defined within the same class of models. The urge for a broader\nframework of expressiveness is not new. Nevertheless, the enterprise is complex\nand a reasonable model-theoretic formal criterion is still wanting. Recently\nthere appeared two criteria in this wider framework, one from García-Matos &\nVäänänen and other from L. Kuijer. We argue that they are not adequate.\nTheir limitations are analyzed and we propose to move to an even broader\nframework lacking model-theoretic notions, which we call \"translational\nexpressiveness\". There is already a criterion in this later framework by\nMossakowski et al., however it turned out to be too lax. We propose some\nadequacy criteria for expressiveness and a formal criterion of translational\nexpressiveness complying with them is given.\n",
"title": "Translations: generalizing relative expressiveness between logics"
}
| null | null |
[
"Computer Science",
"Mathematics"
] | null | true | null |
3585
| null |
Validated
| null | null |
null |
{
"abstract": " This paper considers utility optimal power control for energy harvesting\nwireless devices with a finite capacity battery. The distribution information\nof the underlying wireless environment and harvestable energy is unknown and\nonly outdated system state information is known at the device controller. This\nscenario shares similarity with Lyapunov opportunistic optimization and online\nlearning but is different from both. By a novel combination of Zinkevich's\nonline gradient learning technique and the drift-plus-penalty technique from\nLyapunov opportunistic optimization, this paper proposes a learning-aided\nalgorithm that achieves utility within $O(\\epsilon)$ of the optimal, for any\ndesired $\\epsilon>0$, by using a battery with an $O(1/\\epsilon)$ capacity. The\nproposed algorithm has low complexity and makes power investment decisions\nbased on system history, without requiring knowledge of the system state or its\nprobability distribution.\n",
"title": "Learning Aided Optimization for Energy Harvesting Devices with Outdated State Information"
}
| null | null | null | null | true | null |
3586
| null |
Default
| null | null |
null |
{
"abstract": " Magnetic frustration and low dimensionality can prevent long range magnetic\norder and lead to exotic correlated ground states. SrDy$_2$O$_4$ consists of\nmagnetic Dy$^{3+}$ ions forming magnetically frustrated zig-zag chains along\nthe c-axis and shows no long range order to temperatures as low as $T=60$ mK.\nWe carried out neutron scattering and AC magnetic susceptibility measurements\nusing powder and single crystals of SrDy$_2$O$_4$. Diffuse neutron scattering\nindicates strong one-dimensional (1D) magnetic correlations along the chain\ndirection that can be qualitatively accounted for by the axial next-nearest\nneighbour Ising (ANNNI) model with nearest-neighbor and next-nearest-neighbor\nexchange $J_1=0.3$ meV and $J_2=0.2$ meV, respectively. Three-dimensional (3D)\ncorrelations become important below $T^*\\approx0.7$ K. At $T=60$ mK, the short\nrange correlations are characterized by a putative propagation vector\n$\\textbf{k}_{1/2}=(0,\\frac{1}{2},\\frac{1}{2})$. We argue that the absence of\nlong range order arises from the presence of slowly decaying 1D domain walls\nthat are trapped due to 3D correlations. This stabilizes a low-temperature\nphase without long range magnetic order, but with well-ordered chain segments\nseparated by slowly-moving domain walls.\n",
"title": "Absence of long range order in the frustrated magnet SrDy$_2$O$_4$ due to trapped defects from a dimensionality crossover"
}
| null | null | null | null | true | null |
3587
| null |
Default
| null | null |
null |
{
"abstract": " Gaussian processes are popular and flexible models for spatial, temporal, and\nfunctional data, but they are computationally infeasible for large datasets. We\ndiscuss Gaussian-process approximations that use basis functions at multiple\nresolutions to achieve fast inference and that can (approximately) represent\nany spatial covariance structure. We consider two special cases of this\nmulti-resolution-approximation framework, a taper version and a\ndomain-partitioning (block) version. We describe theoretical properties and\ninference procedures, and study the computational complexity of the methods.\nNumerical comparisons and an application to satellite data are also provided.\n",
"title": "A class of multi-resolution approximations for large spatial datasets"
}
| null | null |
[
"Statistics"
] | null | true | null |
3588
| null |
Validated
| null | null |
null |
{
"abstract": " As an attempt to further elucidate the operating voltage increase in\nInGaN-based light-emitting diodes (LEDs), the radiative and nonradiative\ncurrent components are separately analyzed in combination with the Shockley\ndiode equation. Through the analyses, we have shown that the increase in\noperating voltage is caused by phase space filling effect in high injection. We\nhave also shown that the classical Shockley diode equation is insufficient to\ncomprehensively explain the I-V curve of the LED devices since the transport\nand recombination characteristics of respective current components are\nbasically different. Hence, we have proposed a modified Shockley equation\nsuitable for modern LED devices. Our analysis gives a new insight on the cause\nof the wall-plug-efficiency drop influenced by such factors as the efficiency\ndroop and the high operating voltage in InGaN LEDs.\n",
"title": "Origin of Operating Voltage Increase in InGaN-based Light-emitting Diodes under High Injection: Phase Space Filling Effect on Forward Voltage Characteristics"
}
| null | null |
[
"Physics"
] | null | true | null |
3589
| null |
Validated
| null | null |
null |
{
"abstract": " Many theories have emerged which investigate how in- variance is generated in\nhierarchical networks through sim- ple schemes such as max and mean pooling.\nThe restriction to max/mean pooling in theoretical and empirical studies has\ndiverted attention away from a more general way of generating invariance to\nnuisance transformations. We con- jecture that hierarchically building\nselective invariance (i.e. carefully choosing the range of the transformation\nto be in- variant to at each layer of a hierarchical network) is im- portant\nfor pattern recognition. We utilize a novel pooling layer called adaptive\npooling to find linear pooling weights within networks. These networks with the\nlearnt pooling weights have performances on object categorization tasks that\nare comparable to max/mean pooling networks. In- terestingly, adaptive pooling\ncan converge to mean pooling (when initialized with random pooling weights),\nfind more general linear pooling schemes or even decide not to pool at all. We\nillustrate the general notion of selective invari- ance through object\ncategorization experiments on large- scale datasets such as SVHN and ILSVRC\n2012.\n",
"title": "Emergence of Selective Invariance in Hierarchical Feed Forward Networks"
}
| null | null | null | null | true | null |
3590
| null |
Default
| null | null |
null |
{
"abstract": " We show that for every finitely generated closed subgroup $K$ of a\nnon-solvable Demushkin group $G$, there exists an open subgroup $U$ of $G$\ncontaining $K$, and a continuous homomorphism $\\tau \\colon U \\to K$ satisfying\n$\\tau(k) = k$ for every $k \\in K$. We prove that the intersection of a pair of\nfinitely generated closed subgroups of a Demushkin group is finitely generated\n(giving an explicit bound on the number of generators). Furthermore, we show\nthat these properties of Demushkin groups are preserved under free pro-$p$\nproducts, and deduce that Howson's theorem holds for the Sylow subgroups of the\nabsolute Galois group of a number field. Finally, we confirm two conjectures of\nRibes, thus classifying the finitely generated pro-$p$ M. Hall groups.\n",
"title": "Virtual retraction and Howson's theorem in pro-$p$ groups"
}
| null | null | null | null | true | null |
3591
| null |
Default
| null | null |
null |
{
"abstract": " Convolutional sparse representations are a form of sparse representation with\na dictionary that has a structure that is equivalent to convolution with a set\nof linear filters. While effective algorithms have recently been developed for\nthe convolutional sparse coding problem, the corresponding dictionary learning\nproblem is substantially more challenging. Furthermore, although a number of\ndifferent approaches have been proposed, the absence of thorough comparisons\nbetween them makes it difficult to determine which of them represents the\ncurrent state of the art. The present work both addresses this deficiency and\nproposes some new approaches that outperform existing ones in certain contexts.\nA thorough set of performance comparisons indicates a very wide range of\nperformance differences among the existing and proposed methods, and clearly\nidentifies those that are the most effective.\n",
"title": "Convolutional Dictionary Learning: A Comparative Review and New Algorithms"
}
| null | null | null | null | true | null |
3592
| null |
Default
| null | null |
null |
{
"abstract": " Suppose some future technology enables the same consciously experienced human\nlife to be repeated, identically or nearly so, N times, in series or in\nparallel. Is this roughly N times as valuable as enabling the same life once,\nbecause each life has value and values are additive? Or is it of roughly equal\nvalue as enabling the life once, because only one life is enabled, albeit in a\nphysically unusual way? Does it matter whether the lives are contemporaneous or\nsuccessive? We argue that these questions highlight a hitherto neglected facet\nof population ethics that may become relevant in the not necessarily far\ndistant future.\n",
"title": "Replication Ethics"
}
| null | null | null | null | true | null |
3593
| null |
Default
| null | null |
null |
{
"abstract": " We present the results of a direct-imaging survey for very large separation\n($>$100 au), companions around 95 nearby young K5-L5 stars and brown dwarfs.\nThey are high-likelihood candidates or confirmed members of the young\n($\\lessapprox$150 Myr) $\\beta$ Pictoris and AB Doradus moving groups (ABDMG)\nand the TW Hya, Tucana-Horologium, Columba, Carina, and Argus associations.\nImages in $i'$ and $z'$ filters were obtained with the Gemini Multi-Object\nSpectrograph (GMOS) on Gemini South to search for companions down to an\napparent magnitude of $z'\\sim$22-24 at separations $\\gtrapprox$20\" from the\ntargets and in the remainder of the wide 5.5' $\\times$ 5.5' GMOS field of view.\nThis allowed us to probe the most distant region where planetary-mass\ncompanions could be gravitationally bound to the targets. This region was left\nlargely unstudied by past high-contrast imaging surveys, which probed much\ncloser-in separations. This survey led to the discovery of a planetary-mass\n(9-13 $\\,M_{\\rm{Jup}}$) companion at 2000 au from the M3V star GU Psc, a highly\nprobable member of ABDMG. No other substellar companions were identified. These\nresults allowed us to constrain the frequency of distant planetary-mass\ncompanions (5-13 $\\,M_{\\rm{Jup}}$) to 0.84$_{-0.66}^{+6.73}$% (95% confidence)\nat semimajor axes between 500 and 5000 au around young K5-L5 stars and brown\ndwarfs. This is consistent with other studies suggesting that gravitationally\nbound planetary-mass companions at wide separations from low-mass stars are\nrelatively rare.\n",
"title": "PSYM-WIDE: a survey for large-separation planetary-mass companions to late spectral type members of young moving groups"
}
| null | null | null | null | true | null |
3594
| null |
Default
| null | null |
null |
{
"abstract": " The dimension is a key measure of complexity of partially ordered sets. Small\ndimension allows succinct encoding. Indeed if $P$ has dimension $d$, then to\nknow whether $x \\leq y$ in $P$ it is enough to check whether $x\\leq y$ in each\nof the $d$ linear extensions of a witnessing realizer. Focusing on the encoding\naspect Nešetřil and Pudlák defined a more expressive version of\ndimension. A poset $P$ has boolean dimension at most $d$ if it is possible to\ndecide whether $x \\leq y$ in $P$ by looking at the relative position of $x$ and\n$y$ in only $d$ permutations of the elements of $P$. We prove that posets with\ncover graphs of bounded tree-width have bounded boolean dimension. This stays\nin contrast with the fact that there are posets with cover graphs of tree-width\nthree and arbitrarily large dimension. This result might be a step towards a\nresolution of the long-standing open problem: Do planar posets have bounded\nboolean dimension?\n",
"title": "Boolean dimension and tree-width"
}
| null | null | null | null | true | null |
3595
| null |
Default
| null | null |
null |
{
"abstract": " We define the \\emph{visual complexity} of a plane graph drawing to be the\nnumber of basic geometric objects needed to represent all its edges. In\nparticular, one object may represent multiple edges (e.g., one needs only one\nline segment to draw a path with an arbitrary number of edges). Let $n$ denote\nthe number of vertices of a graph. We show that trees can be drawn with $3n/4$\nstraight-line segments on a polynomial grid, and with $n/2$ straight-line\nsegments on a quasi-polynomial grid. Further, we present an algorithm for\ndrawing planar 3-trees with $(8n-17)/3$ segments on an $O(n)\\times O(n^2)$\ngrid. This algorithm can also be used with a small modification to draw maximal\nouterplanar graphs with $3n/2$ edges on an $O(n)\\times O(n^2)$ grid. We also\nstudy the problem of drawing maximal planar graphs with circular arcs and\nprovide an algorithm to draw such graphs using only $(5n - 11)/3$ arcs. This is\nsignificantly smaller than the lower bound of $2n$ for line segments for a\nnontrivial graph class.\n",
"title": "Drawing Planar Graphs with Few Geometric Primitives"
}
| null | null | null | null | true | null |
3596
| null |
Default
| null | null |
null |
{
"abstract": " We report new multi-colour photometry and high-resolution spectroscopic\nobservations of the long-period variable V501 Aur, previously considered to be\na weak-lined T-Tauri star belonging to the Taurus-Auriga star-forming region.\nThe spectroscopic observations reveal that V501 Aur is a single-lined\nspectroscopic binary system with a 68.8-day orbital period, a slightly\neccentric orbit (e ~ 0.03), and a systemic velocity discrepant from the mean of\nTaurus-Auriga. The photometry shows quasi-periodic variations on a different,\n~55-day timescale that we attribute to rotational modulation by spots. No\neclipses are seen. The visible object is a rapidly rotating (vsini ~ 25 km/s)\nearly K star, which along with the rotation period implies it must be large (R\n> 26.3 Rsun), as suggested also by spectroscopic estimates indicating a low\nsurface gravity. The parallax from the Gaia mission and other independent\nestimates imply a distance much greater than the Taurus-Auriga region,\nconsistent with the giant interpretation. Taken together, this evidence\ntogether with a re-evaluation of the LiI~$\\lambda$6707 and H$\\alpha$ lines\nshows that V501 Aur is not a T-Tauri star, but is instead a field binary with a\ngiant primary far behind the Taurus-Auriga star-forming region. The large mass\nfunction from the spectroscopic orbit and a comparison with stellar evolution\nmodels suggest the secondary may be an early-type main-sequence star.\n",
"title": "On the nature of the candidate T-Tauri star V501 Aurigae"
}
| null | null | null | null | true | null |
3597
| null |
Default
| null | null |
null |
{
"abstract": " The success of various applications including robotics, digital content\ncreation, and visualization demand a structured and abstract representation of\nthe 3D world from limited sensor data. Inspired by the nature of human\nperception of 3D shapes as a collection of simple parts, we explore such an\nabstract shape representation based on primitives. Given a single depth image\nof an object, we present 3D-PRNN, a generative recurrent neural network that\nsynthesizes multiple plausible shapes composed of a set of primitives. Our\ngenerative model encodes symmetry characteristics of common man-made objects,\npreserves long-range structural coherence, and describes objects of varying\ncomplexity with a compact representation. We also propose a method based on\nGaussian Fields to generate a large scale dataset of primitive-based shape\nrepresentations to train our network. We evaluate our approach on a wide range\nof examples and show that it outperforms nearest-neighbor based shape retrieval\nmethods and is on-par with voxel-based generative models while using a\nsignificantly reduced parameter space.\n",
"title": "3D-PRNN: Generating Shape Primitives with Recurrent Neural Networks"
}
| null | null | null | null | true | null |
3598
| null |
Default
| null | null |
null |
{
"abstract": " The defect of valued field extensions is a major obstacle in open problems in\nresolution of singularities and in the model theory of valued fields, whenever\npositive characteristic is involved. We continue the detailed study of defect\nextensions through the tool of distances, which measure how well an element in\nan immediate extension can be approximated by elements from the base field. We\nshow that in several situations the number of essentially distinct distances in\nfixed extensions, or even just over a fixed base field, is finite, and we\ncompute upper bounds. We apply this to the special case of valued functions\nfields over perfect base fields. This provides important information used in\nforthcoming research on relative resolution problems.\n",
"title": "Counting the number of distinct distances of elements in valued field extensions"
}
| null | null | null | null | true | null |
3599
| null |
Default
| null | null |
null |
{
"abstract": " Neural networks are known to be vulnerable to adversarial examples. In this\nnote, we evaluate the two white-box defenses that appeared at CVPR 2018 and\nfind they are ineffective: when applying existing techniques, we can reduce the\naccuracy of the defended models to 0%.\n",
"title": "On the Robustness of the CVPR 2018 White-Box Adversarial Example Defenses"
}
| null | null | null | null | true | null |
3600
| null |
Default
| null | null |
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