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{
"abstract": " The human brain is capable of diverse feats of intelligence. A particularly\nsalient example is the ability to deduce structure from time-varying auditory\nand visual stimuli, enabling humans to master the rules of language and to\nbuild rich expectations of their physical environment. The broad relevance of\nthis ability for human cognition motivates the need for a first-principles\nmodel explicating putative mechanisms. Here we propose a general framework for\nstructural learning in the brain, composed of an evolving, high-dimensional\ndynamical system driven by external stimuli or internal processes. We\noperationalize the scenario in which humans learn the rules that generate a\nsequence of stimuli, rather than the exemplar stimuli themselves. We model\nexternal stimuli as seemingly disordered chaotic time series generated by\ncomplex dynamical systems; the underlying structure being deduced is then that\nof the corresponding chaotic attractor. This approach allows us to demonstrate\nand theoretically explain the emergence of five distinct phenomena reminiscent\nof cognitive functions: (i) learning the structure of a chaotic system purely\nfrom time series, (ii) generating new streams of stimuli from a chaotic system,\n(iii) switching stream generation among multiple learned chaotic systems,\neither spontaneously or in response to external perturbations, (iv) inferring\nmissing data from sparse observations of the chaotic system, and (v)\ndeciphering superimposed input from different chaotic systems. Numerically, we\nshow that these phenomena emerge naturally from a recurrent neural network of\nErdos-Renyi topology in which the synaptic strengths adapt in a Hebbian-like\nmanner. Broadly, our work blends chaotic theory and artificial neural networks\nto answer the long standing question of how neural systems can learn the\nstructure underlying temporal sequences of stimuli.\n",
"title": "A Parsimonious Dynamical Model for Structural Learning in the Human Brain"
}
| null | null | null | null | true | null |
4601
| null |
Default
| null | null |
null |
{
"abstract": " Yang (1978) considered an empirical estimate of the mean residual life\nfunction on a fixed finite interval. She proved it to be strongly uniformly\nconsistent and (when appropriately standardized) weakly convergent to a\nGaussian process. These results are extended to the whole half line, and the\nvariance of the the limiting process is studied. Also, nonparametric\nsimultaneous confidence bands for the mean residual life function are obtained\nby transforming the limiting process to Brownian motion.\n",
"title": "Estimation of mean residual life"
}
| null | null | null | null | true | null |
4602
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| null | null |
null |
{
"abstract": " We calculate ghost characters for the (5,6)-torus knot, and using them we\nshow that the (5,6)-torus knot gives a counter-example of Ng's conjecture\nconcerned with the relationship between degree 0 abelian knot contact homology\nand the character variety of the 2-fold branched covering of the 3-sphere\nbranched along the knot.\n",
"title": "Trace-free characters and abelian knot contact homology II"
}
| null | null | null | null | true | null |
4603
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null |
{
"abstract": " We aim to clarify the role that absorption plays in nonlinear optical\nprocesses in a variety of metallic nanostructures and show how it relates to\nemission and conversion efficiency. We define a figure of merit that\nestablishes the structure's ability to either favor or impede second harmonic\ngeneration. Our findings suggest that, despite the best efforts embarked upon\nto enhance local fields and light coupling via plasmon excitation, nearly\nalways the absorbed harmonic energy far surpasses the harmonic energy emitted\nin the far field. Qualitative and quantitative understanding of absorption\nprocesses is crucial in the evaluation of practical designs of plasmonic\nnanostructures for the purpose of frequency mixing.\n",
"title": "Surface Plasmon Excitation of Second Harmonic light: Emission and Absorption"
}
| null | null | null | null | true | null |
4604
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null |
{
"abstract": " The data center networks $D_{n,k}$, proposed in 2008, has many desirable\nfeatures such as high network capacity. A kind of generalization of\ndiagnosability for network $G$ is $g$-good-neighbor diagnosability which is\ndenoted by $t_g(G)$. Let $\\kappa^g(G)$ be the $R^g$-connectivity. Lin et. al.\nin [IEEE Trans. on Reliability, 65 (3) (2016) 1248--1262] and Xu et. al in\n[Theor. Comput. Sci. 659 (2017) 53--63] gave the same problem independently\nthat: the relationship between the $R^g$-connectivity $\\kappa^g(G)$ and\n$t_g(G)$ of a general graph $G$ need to be studied in the future. In this\npaper, this open problem is solved for general regular graphs. We firstly\nestablish the relationship of $\\kappa^g(G)$ and $t_g(G)$, and obtain that\n$t_g(G)=\\kappa^g(G)+g$ under some conditions. Secondly, we obtain the\n$g$-good-neighbor diagnosability of $D_{k,n}$ which are\n$t_g(D_{k,n})=(g+1)(k-1)+n+g$ for $1\\leq g\\leq n-1$ under the PMC model and the\nMM model, respectively. Further more, we show that $D_{k,n}$ is tightly super\n$(n+k-1)$-connected for $n\\geq 2$ and $k\\geq 2$ and we also prove that the\nlargest connected component of the survival graph contains almost all of the\nremaining vertices in $D_{k,n}$ when $2k+n-2$ vertices removed.\n",
"title": "Fault diagnosability of data center networks"
}
| null | null | null | null | true | null |
4605
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| null | null |
null |
{
"abstract": " Turbulence is the leading candidate for angular momentum transport in\nprotoplanetary disks and therefore influences disk lifetimes and planet\nformation timescales. However, the turbulent properties of protoplanetary disks\nare poorly constrained observationally. Recent studies have found turbulent\nspeeds smaller than what fully-developed MRI would produce (Flaherty et al.\n2015, 2017). However, existing studies assumed a constant CO/H2 ratio of 0.0001\nin locations where CO is not frozen-out or photo-dissociated. Our previous\nstudies of evolving disk chemistry indicate that CO is depleted by\nincorporation into complex organic molecules well inside the freeze-out radius\nof CO. We consider the effects of this chemical depletion on measurements of\nturbulence. Simon et al. (2015) suggested that the ratio of the peak line flux\nto the flux at line center of the CO J=3-2 transition is a reasonable\ndiagnostic of turbulence, so we focus on that metric, while adding some\nanalysis of the more complex effects on spatial distribution. We simulate the\nemission lines of CO based on chemical evolution models presented in Yu et al.\n(2016), and find that the peak-to-trough ratio changes as a function of time as\nCO is destroyed. Specifically, a CO-depleted disk with high turbulent velocity\nmimics the peak-to-trough ratios of a non-CO-depleted disk with lower turbulent\nvelocity. We suggest that disk observers and modelers take into account the\npossibility of CO depletion when using line peak-to-trough ratios to constrain\nthe degree of turbulence in disks. Assuming that CO/H2 = 0.0001 at all disk\nradii can lead to underestimates of turbulent speeds in the disk by at least\n0.2 km/s.\n",
"title": "The Effects of Protostellar Disk Turbulence on CO Emission Lines: A Comparison Study of Disks with Constant CO Abundance vs. Chemically Evolving Disks"
}
| null | null | null | null | true | null |
4606
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| null | null |
null |
{
"abstract": " This paper proposes a general framework of multi-armed bandit (MAB) processes\nby introducing a type of restrictions on the switches among arms evolving in\ncontinuous time.\nThe Gittins index process is constructed for any single arm subject to the\nrestrictions on switches and then the optimality of the corresponding Gittins\nindex rule is established. The Gittins indices defined in this paper are\nconsistent with the ones for MAB processes in continuous time, integer time,\nsemi-Markovian setting as well as general discrete time setting, so that the\nnew theory covers the classical models as special cases and also applies to\nmany other situations that have not yet been touched in the literature. While\nthe proof of the optimality of Gittins index policies benefits from ideas in\nthe existing theory of MAB processes in continuous time, new techniques are\nintroduced which drastically simplify the proof.\n",
"title": "A General Framework of Multi-Armed Bandit Processes by Arm Switch Restrictions"
}
| null | null | null | null | true | null |
4607
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| null | null |
null |
{
"abstract": " Urban environments offer a challenging scenario for autonomous driving.\nGlobally localizing information, such as a GPS signal, can be unreliable due to\nsignal shadowing and multipath errors. Detailed a priori maps of the\nenvironment with sufficient information for autonomous navigation typically\nrequire driving the area multiple times to collect large amounts of data,\nsubstantial post-processing on that data to obtain the map, and then\nmaintaining updates on the map as the environment changes. This paper addresses\nthe issue of autonomous driving in an urban environment by investigating\nalgorithms and an architecture to enable fully functional autonomous driving\nwith limited information. An algorithm to autonomously navigate urban roadways\nwith little to no reliance on an a priori map or GPS is developed. Localization\nis performed with an extended Kalman filter with odometry, compass, and sparse\nlandmark measurement updates. Navigation is accomplished by a compass-based\nnavigation control law. Key results from Monte Carlo studies show success rates\nof urban navigation under different environmental conditions. Experiments\nvalidate the simulated results and demonstrate that, for given test conditions,\nan expected range can be found for a given success rate.\n",
"title": "Autonomous Urban Localization and Navigation with Limited Information"
}
| null | null | null | null | true | null |
4608
| null |
Default
| null | null |
null |
{
"abstract": " We give improved algorithms for the $\\ell_{p}$-regression problem, $\\min_{x}\n\\|x\\|_{p}$ such that $A x=b,$ for all $p \\in (1,2) \\cup (2,\\infty).$ Our\nalgorithms obtain a high accuracy solution in $\\tilde{O}_{p}(m^{\\frac{|p-2|}{2p\n+ |p-2|}}) \\le \\tilde{O}_{p}(m^{\\frac{1}{3}})$ iterations, where each iteration\nrequires solving an $m \\times m$ linear system, $m$ being the dimension of the\nambient space.\nBy maintaining an approximate inverse of the linear systems that we solve in\neach iteration, we give algorithms for solving $\\ell_{p}$-regression to $1 /\n\\text{poly}(n)$ accuracy that run in time $\\tilde{O}_p(m^{\\max\\{\\omega,\n7/3\\}}),$ where $\\omega$ is the matrix multiplication constant. For the current\nbest value of $\\omega > 2.37$, we can thus solve $\\ell_{p}$ regression as fast\nas $\\ell_{2}$ regression, for all constant $p$ bounded away from $1.$\nOur algorithms can be combined with fast graph Laplacian linear equation\nsolvers to give minimum $\\ell_{p}$-norm flow / voltage solutions to $1 /\n\\text{poly}(n)$ accuracy on an undirected graph with $m$ edges in\n$\\tilde{O}_{p}(m^{1 + \\frac{|p-2|}{2p + |p-2|}}) \\le\n\\tilde{O}_{p}(m^{\\frac{4}{3}})$ time.\nFor sparse graphs and for matrices with similar dimensions, our iteration\ncounts and running times improve on the $p$-norm regression algorithm by\n[Bubeck-Cohen-Lee-Li STOC`18] and general-purpose convex optimization\nalgorithms. At the core of our algorithms is an iterative refinement scheme for\n$\\ell_{p}$-norms, using the smoothed $\\ell_{p}$-norms introduced in the work of\nBubeck et al. Given an initial solution, we construct a problem that seeks to\nminimize a quadratically-smoothed $\\ell_{p}$ norm over a subspace, such that a\ncrude solution to this problem allows us to improve the initial solution by a\nconstant factor, leading to algorithms with fast convergence.\n",
"title": "Iterative Refinement for $\\ell_p$-norm Regression"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
4609
| null |
Validated
| null | null |
null |
{
"abstract": " In this article, we give the explicit minimal free resolution of the\nassociated graded ring of certain affine monomial curves in affine 4-space\nbased on the standard basis theory. As a result, we give the minimal graded\nfree resolution and compute the Hilbert function of the tangent cone of these\nfamilies.\n",
"title": "Minimal free resolution of the associated graded ring of certain monomial curves"
}
| null | null |
[
"Mathematics"
] | null | true | null |
4610
| null |
Validated
| null | null |
null |
{
"abstract": " Current approaches for Knowledge Distillation (KD) either directly use\ntraining data or sample from the training data distribution. In this paper, we\ndemonstrate effectiveness of 'mismatched' unlabeled stimulus to perform KD for\nimage classification networks. For illustration, we consider scenarios where\nthis is a complete absence of training data, or mismatched stimulus has to be\nused for augmenting a small amount of training data. We demonstrate that\nstimulus complexity is a key factor for distillation's good performance. Our\nexamples include use of various datasets for stimulating MNIST and CIFAR\nteachers.\n",
"title": "Knowledge distillation using unlabeled mismatched images"
}
| null | null | null | null | true | null |
4611
| null |
Default
| null | null |
null |
{
"abstract": " This article argues for the importance of forbidden triads - open triads with\nhigh-weight edges - in predicting success in creative fields. Forbidden triads\nhad been treated as a residual category beyond closed and open triads, yet I\nargue that these structures provide opportunities to combine socially evolved\nstyles in new ways. Using data on the entire history of recorded jazz from 1896\nto 2010, I show that observed collaborations have tolerated the openness of\nhigh weight triads more than expected, observed jazz sessions had more\nforbidden triads than expected, and the density of forbidden triads contributed\nto the success of recording sessions, measured by the number of record releases\nof session material. The article also shows that the sessions of Miles Davis\nhad received an especially high boost from forbidden triads.\n",
"title": "Forbidden triads and Creative Success in Jazz: The Miles Davis Factor"
}
| null | null | null | null | true | null |
4612
| null |
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| null | null |
null |
{
"abstract": " Solar system small bodies come in a wide variety of shapes and sizes, which\nare achieved following very individual evolutional paths through billions of\nyears. This paper focuses on the reshaping process of rubble-pile asteroids\ndriven by meteorite impacts. In our study, numerous possible equilibrium\nconfigurations are obtained via Monte Carlo simulation, and the structural\nstability of these configurations is determined via eigen analysis of the\ngeometric constructions. The eigen decomposition reveals a connection between\nthe cluster's reactions and the types of external disturbance. Numerical\nsimulations are performed to verify the analytical results. The gravitational\nN-body code pkdgrav is used to mimic the responses of the cluster under\nintermittent non-dispersive impacts. We statistically confirm that the\nstability index, the total gravitational potential and the volume of inertia\nellipsoid show consistent tendency of variation. A common regime is found in\nwhich the clusters tend towards crystallization under intermittent impacts,\ni.e., only the configurations with high structural stability survive under the\nexternal disturbances. The results suggest the trivial non-disruptive impacts\nmight play an important role in the rearrangement of the constituent blocks,\nwhich may strengthen these rubble piles and help to build a robust structure\nunder impacts of similar magnitude. The final part of this study consists of\nsystematic simulations over two parameters, the projectile momentum and the\nrotational speed of the cluster. The results show a critical value exists for\nthe projectile momentum, as predicted by theory, below which all clusters\nbecome responseless to external disturbances; and the rotation proves to be\nsignificant for it exhibits an \"enhancing\" effect on loose-packed clusters,\nwhich coincides with the observation that several fast-spinning asteroids have\nlow bulk densities.\n",
"title": "Structural analysis of rubble-pile asteroids applied to collisional evolution"
}
| null | null | null | null | true | null |
4613
| null |
Default
| null | null |
null |
{
"abstract": " The Leah-Hamiltonian, $H(x,y)=y^2/2+3x^{4/3}/4$, is introduced as a\nfunctional equation for $x(t)$ and $y(t)$. By means of a nonlinear\ntransformation to new independent variables, we show that this functional\nequation has a special class of periodic solutions which we designate the Imani\nfunctions. The explicit construction of these functions is done such that they\npossess many of the general properties of the standard trigonometric cosine and\nsine functions. We conclude by providing a listing of a number of currently\nunresolved issues relating to the Imani functions.\n",
"title": "The Imani Periodic Functions: Genesis and Preliminary Results"
}
| null | null | null | null | true | null |
4614
| null |
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| null | null |
null |
{
"abstract": " Nuclear magnetic resonance (NMR) spectroscopy is one of the leading\ntechniques for protein studies. The method features a number of properties,\nallowing to explain macromolecular interactions mechanistically and resolve\nstructures with atomic resolution. However, due to laborious data analysis, a\nfull potential of NMR spectroscopy remains unexploited. Here we present an\napproach aiming at automation of two major bottlenecks in the analysis\npipeline, namely, peak picking and chemical shift assignment. Our approach\ncombines deep learning, non-parametric models and combinatorial optimization,\nand is able to detect signals of interest in a multidimensional NMR data with\nhigh accuracy and match them with atoms in medium-length protein sequences,\nwhich is a preliminary step to solve protein spatial structure.\n",
"title": "Towards fully automated protein structure elucidation with NMR spectroscopy"
}
| null | null | null | null | true | null |
4615
| null |
Default
| null | null |
null |
{
"abstract": " For every genus $g\\geq 2$, we construct an infinite family of strongly\nquasipositive fibred knots having the same Seifert form as the torus knot\n$T(2,2g+1)$. In particular, their signatures and four-genera are maximal and\ntheir homological monodromies (hence their Alexander module structures) agree.\nOn the other hand, the geometric stretching factors are pairwise distinct and\nthe knots are pairwise not ribbon concordant.\n",
"title": "On families of fibred knots with equal Seifert forms"
}
| null | null | null | null | true | null |
4616
| null |
Default
| null | null |
null |
{
"abstract": " Objective: Absolute images have important applications in medical Electrical\nImpedance Tomography (EIT) imaging, but the traditional minimization and\nstatistical based computations are very sensitive to modeling errors and noise.\nIn this paper, it is demonstrated that D-bar reconstruction methods for\nabsolute EIT are robust to such errors. Approach: The effects of errors in\ndomain shape and electrode placement on absolute images computed with 2D D-bar\nreconstruction algorithms are studied on experimental data. Main Results: It is\ndemonstrated with tank data from several EIT systems that these methods are\nquite robust to such modeling errors, and furthermore the artefacts arising\nfrom such modeling errors are similar to those occurring in classic\ntime-difference EIT imaging. Significance: This study is promising for clinical\napplications where absolute EIT images are desirable, but previously thought\nimpossible.\n",
"title": "Robust Computation in 2D Absolute EIT (a-EIT) Using D-bar Methods with the `exp' Approximation"
}
| null | null | null | null | true | null |
4617
| null |
Default
| null | null |
null |
{
"abstract": " Epidemic outbreaks are an important healthcare challenge, especially in\ndeveloping countries where they represent one of the major causes of mortality.\nApproaches that can rapidly target subpopulations for surveillance and control\nare critical for enhancing containment processes during epidemics.\nUsing a real-world dataset from Ivory Coast, this work presents an attempt to\nunveil the socio-geographical heterogeneity of disease transmission dynamics.\nBy employing a spatially explicit meta-population epidemic model derived from\nmobile phone Call Detail Records (CDRs), we investigate how the differences in\nmobility patterns may affect the course of a realistic infectious disease\noutbreak. We consider different existing measures of the spatial dimension of\nhuman mobility and interactions, and we analyse their relevance in identifying\nthe highest risk sub-population of individuals, as the best candidates for\nisolation countermeasures. The approaches presented in this paper provide\nfurther evidence that mobile phone data can be effectively exploited to\nfacilitate our understanding of individuals' spatial behaviour and its\nrelationship with the risk of infectious diseases' contagion. In particular, we\nshow that CDRs-based indicators of individuals' spatial activities and\ninteractions hold promise for gaining insight of contagion heterogeneity and\nthus for developing containment strategies to support decision-making during\ncountry-level pandemics.\n",
"title": "A Comparison of Spatial-based Targeted Disease Containment Strategies using Mobile Phone Data"
}
| null | null |
[
"Computer Science",
"Physics"
] | null | true | null |
4618
| null |
Validated
| null | null |
null |
{
"abstract": " We report on the first streaking measurement of water-window attosecond\npulses generated via high harmonic generation, driven by sub-2-cycle,\nCEP-stable, 1850 nm laser pulses. Both the central photon energy and the energy\nbandwidth far exceed what has been demonstrated thus far, warranting the\ninvestigation of the attosecond streaking technique for the soft X-ray regime\nand the limits of the FROGCRAB retrieval algorithm under such conditions. We\nalso discuss the problem of attochirp compensation and issues regarding much\nlower photo-ionization cross sections compared with the XUV in addition to the\nfact that several shells of target gases are accessed simultaneously. Based on\nour investigation, we caution that the vastly different conditions in the soft\nX-ray regime warrant a diligent examination of the fidelity of the measurement\nand the retrieval procedure.\n",
"title": "Attosecond Streaking in the Water Window: A New Regime of Attosecond Pulse Characterization"
}
| null | null | null | null | true | null |
4619
| null |
Default
| null | null |
null |
{
"abstract": " We investigate the intrinsic Baldwin effect (Beff) of the broad H$\\alpha$ and\nH$\\beta$ emission lines for six Type 1 active galactic nuclei (AGNs) with\ndifferent broad line characteristics: two Seyfert 1 (NGC 4151 and NGC 5548),\ntwo AGNs with double-peaked broad line profiles (3C 390.3 and Arp 102B), one\nnarrow line Seyfert 1 (Ark 564), and one high-luminosity quasar with highly red\nasymmetric broad line profiles (E1821+643). We found that a significant\nintrinsic Beff was present in all Type 1 AGNs in our sample. Moreover, we do\nnot see strong difference in intrinsic Beff slopes in different types of AGNs\nwhich probably have different physical properties, such as inclination, broad\nline region geometry, or accretion rate. Additionally, we found that the\nintrinsic Beff was not connected with the global one, which, instead, could not\nbe detected in the broad H$\\alpha$ or H$\\beta$ emission lines. In the case of\nNGC 4151, the detected variation of the Beff slope could be due to the change\nin the site of line formation in the BLR. Finally, the intrinsic Beff might be\ncaused by the additional optical continuum component that is not part of the\nionization continuum.\n",
"title": "The intrinsic Baldwin effect in broad Balmer lines of six long-term monitored AGNs"
}
| null | null | null | null | true | null |
4620
| null |
Default
| null | null |
null |
{
"abstract": " HIV/AIDS spread depends upon complex patterns of interaction among various\nsub-sets emerging at population level. This added complexity makes it difficult\nto study and model AIDS and its dynamics. AIDS is therefore a natural candidate\nto be modeled using agent-based modeling, a paradigm well-known for modeling\nComplex Adaptive Systems (CAS). While agent-based models are also well-known to\neffectively model CAS, often times models can tend to be ambiguous and the use\nof purely text-based specifications (such as ODD) can make models difficult to\nbe replicated. Previous work has shown how formal specification may be used in\nconjunction with agent-based modeling to develop models of various CAS.\nHowever, to the best of our knowledge, no such model has been developed in\nconjunction with AIDS. In this paper, we present a Formal Agent-Based\nSimulation modeling framework (FABS-AIDS) for an AIDS-based CAS. FABS-AIDS\nemploys the use of a formal specification model in conjunction with an\nagent-based model to reduce ambiguity as well as improve clarity in the model\ndefinition. The proposed model demonstrates the effectiveness of using formal\nspecification in conjunction with agent-based simulation for developing models\nof CAS in general and, social network-based agent-based models, in particular.\n",
"title": "A Novel Formal Agent-based Simulation Modeling Framework of an AIDS Complex Adaptive System"
}
| null | null | null | null | true | null |
4621
| null |
Default
| null | null |
null |
{
"abstract": " Biluminescent organic emitters show simultaneous fluorescence and\nphosphorescence at room temperature. So far, the optimization of the room\ntemperature phosphorescence (RTP) in these materials has drawn the attention of\nresearch. However, the continuous wave operation of these emitters will\nconsequently turn them into systems with vastly imbalanced singlet and triplet\npopulations, which is due to the respective excited state lifetimes. This study\nreports on the exciton dynamics of the biluminophore NPB\n(N,N-di(1-naphthyl)-N,N-diphenyl-(1,1-biphenyl)-4,4-diamine). In the extreme\ncase, the singlet and triplet exciton lifetimes stretch from 3 ns to 300 ms,\nrespectively. Through sample engineering and oxygen quenching experiments, the\ntriplet exciton density can be controlled over several orders of magnitude\nallowing to studying exciton interactions between singlet and triplet\nmanifolds. The results show, that singlet-triplet annihilation reduces the\noverall biluminescence efficiency already at moderate excitation levels.\nAdditionally, the presented system represents an illustrative role model to\nstudy excitonic effects in organic materials.\n",
"title": "Interplay of Fluorescence and Phosphorescence in Organic Biluminescent Emitters"
}
| null | null | null | null | true | null |
4622
| null |
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| null | null |
null |
{
"abstract": " An instability of a liquid droplet traversed by an energetic ion is explored.\nThis instability is brought about by the predicted shock wave induced by the\nion. An observation of multifragmentation of small droplets traversed by ions\nwith high linear energy transfer is suggested to demonstrate the existence of\nshock waves. A number of effects are analysed in effort to find the conditions\nfor such an experiment to be signifying. The presence of shock waves crucially\naffects the scenario of radiation damage with ions since the shock waves\nsignificantly contribute to the thermomechanical damage of biomolecules as well\nas the transport of reactive species. While the scenario has been upheld by\nanalyses of biological experiments, the shock waves have not yet been observed\ndirectly, regardless of a number of ideas of experiments to detect them were\nexchanged at conferences.\n",
"title": "Ion-impact-induced multifragmentation of liquid droplets"
}
| null | null | null | null | true | null |
4623
| null |
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| null | null |
null |
{
"abstract": " Navigating in search and rescue environments is challenging, since a variety\nof terrains has to be considered. Hybrid driving-stepping locomotion, as\nprovided by our robot Momaro, is a promising approach. Similar to other\nlocomotion methods, it incorporates many degrees of freedom---offering high\nflexibility but making planning computationally expensive for larger\nenvironments.\nWe propose a navigation planning method, which unifies different levels of\nrepresentation in a single planner. In the vicinity of the robot, it provides\nplans with a fine resolution and a high robot state dimensionality. With\nincreasing distance from the robot, plans become coarser and the robot state\ndimensionality decreases. We compensate this loss of information by enriching\ncoarser representations with additional semantics. Experiments show that the\nproposed planner provides plans for large, challenging scenarios in feasible\ntime.\n",
"title": "Planning Hybrid Driving-Stepping Locomotion on Multiple Levels of Abstraction"
}
| null | null | null | null | true | null |
4624
| null |
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| null | null |
null |
{
"abstract": " We point out that current textbooks of modern physics are a century\nout-of-date in their treatment of blackbody radiation within classical physics.\nRelativistic classical electrodynamics including classical electromagnetic\nzero-point radiation gives the Planck spectrum with zero-point radiation as the\nblackbody radiation spectrum. In contrast, nonrelativistic mechanics cannot\nsupport the idea of zero-point energy; therefore if nonrelativistic classical\nstatistical mechanics or nonrelativistic mechanical scatterers are invoked for\nradiation equilibrium, one arrives at only the low-frequency Rayleigh-Jeans\npart of the spectrum which involves no zero-point energy, and does not include\nthe high-frequency part of the spectrum involving relativistically-invariant\nclassical zero-point radiation. Here we first discuss the correct understanding\nof blackbody radiation within relativistic classical physics, and then we\nreview the historical treatment. Finally, we point out how the presence of\nLorentz-invariant classical zero-point radiation and the use of relativistic\nparticle interactions transform the previous historical arguments so as now to\ngive the Planck spectrum including classical zero-point radiation. Within\nrelativistic classical electromagnetic theory, Planck's constant h appears as\nthe scale of source-free zero-point radiation.\n",
"title": "Blackbody Radiation in Classical Physics: A Historical Perspective"
}
| null | null | null | null | true | null |
4625
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null |
{
"abstract": " The reionization of the Universe is one of the most important topics of\npresent day astrophysical research. The most plausible candidates for the\nreionization process are star-forming galaxies, which according to the\npredictions of the majority of the theoretical and semi-analytical models\nshould dominate the HI ionizing background at z~3. We aim at measuring the\nLyman continuum escape fraction, which is one of the key parameters to compute\nthe contribution of star-forming galaxies to the UV background. We have used\nultra-deep U-band imaging (U=30.2mag at 1sigma) by LBC/LBT in the\nCANDELS/GOODS-North field, as well as deep imaging in COSMOS and EGS fields, in\norder to estimate the Lyman continuum escape fraction of 69 star-forming\ngalaxies with secure spectroscopic redshifts at 3.27<z<3.40 to faint magnitude\nlimits (L=0.2L*, or equivalently M1500~-19). We have measured through stacks a\nstringent upper limit (<1.7% at 1sigma) for the relative escape fraction of HI\nionizing photons from bright galaxies (L>L*), while for the faint population\n(L=0.2L*) the limit to the escape fraction is ~10%. We have computed the\ncontribution of star-forming galaxies to the observed UV background at z~3 and\nwe have found that it is not enough to keep the Universe ionized at these\nredshifts, unless their escape fraction increases significantly (>10%) at low\nluminosities (M1500>-19). We compare our results on the Lyman continuum escape\nfraction of high-z galaxies with recent estimates in the literature and discuss\nfuture prospects to shed light on the end of the Dark Ages. In the future,\nstrong gravitational lensing will be fundamental to measure the Lyman continuum\nescape fraction down to faint magnitudes (M1500~-16) which are inaccessible\nwith the present instrumentation on blank fields.\n",
"title": "The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC"
}
| null | null | null | null | true | null |
4626
| null |
Default
| null | null |
null |
{
"abstract": " We study the effect of different feedback prescriptions on the properties of\nthe low redshift ($z\\leq1.6$) Ly$\\alpha$ forest using a selection of\nhydrodynamical simulations drawn from the Sherwood simulation suite. The\nsimulations incorporate stellar feedback, AGN feedback and a simplified scheme\nfor efficiently modelling the low column density Ly$\\alpha$ forest. We confirm\na discrepancy remains between Cosmic Origins Spectrograph (COS) observations of\nthe Ly$\\alpha$ forest column density distribution function (CDDF) at $z \\simeq\n0.1$ for high column density systems ($N_{\\rm HI}>10^{14}\\rm\\,cm^{-2}$), as\nwell as Ly$\\alpha$ velocity widths that are too narrow compared to the COS\ndata. Stellar or AGN feedback -- as currently implemented in our simulations --\nhave only a small effect on the CDDF and velocity width distribution. We\nconclude that resolving the discrepancy between the COS data and simulations\nrequires an increase in the temperature of overdense gas with $\\Delta=4$--$40$,\neither through additional He$\\,\\rm \\scriptstyle II\\ $ photo-heating at $z>2$ or\nfine-tuned feedback that ejects overdense gas into the IGM at just the right\ntemperature for it to still contribute significantly to the Ly$\\alpha$ forest.\nAlternatively a larger, currently unresolved turbulent component to the line\nwidth could resolve the discrepancy.\n",
"title": "The effect of stellar and AGN feedback on the low redshift Lyman-$α$ forest in the Sherwood simulation suite"
}
| null | null | null | null | true | null |
4627
| null |
Default
| null | null |
null |
{
"abstract": " The first direct detection of the asteroidal YORP effect, a phenomenon that\nchanges the spin states of small bodies due to thermal reemission of sunlight\nfrom their surfaces, was obtained for (54509) YORP 2000 PH5. Such an alteration\ncan slowly increase the rotation rate of asteroids, driving them to reach their\nfission limit and causing their disruption. This process can produce binaries\nand unbound asteroid pairs. Secondary fission opens the door to the eventual\nformation of transient but genetically-related groupings. Here, we show that\nthe small near-Earth asteroid (NEA) 2017 FZ2 was a co-orbital of our planet of\nthe quasi-satellite type prior to their close encounter on 2017 March 23.\nBecause of this flyby with the Earth, 2017 FZ2 has become a non-resonant NEA.\nOur N-body simulations indicate that this object may have experienced\nquasi-satellite engagements with our planet in the past and it may return as a\nco-orbital in the future. We identify a number of NEAs that follow similar\npaths, the largest named being YORP, which is also an Earth's co-orbital. An\napparent excess of NEAs moving in these peculiar orbits is studied within the\nframework of two orbit population models. A possibility that emerges from this\nanalysis is that such an excess, if real, could be the result of mass shedding\nfrom YORP itself or a putative larger object that produced YORP. Future\nspectroscopic observations of 2017 FZ2 during its next visit in 2018 (and of\nrelated objects when feasible) may be able to confirm or reject this\ninterpretation.\n",
"title": "Asteroid 2017 FZ2 et al.: signs of recent mass-shedding from YORP?"
}
| null | null | null | null | true | null |
4628
| null |
Default
| null | null |
null |
{
"abstract": " We study the convergence of the log-linear non-Bayesian social learning\nupdate rule, for a group of agents that collectively seek to identify a\nparameter that best describes a joint sequence of observations. Contrary to\nrecent literature, we focus on the case where agents assign decaying weights to\nits neighbors, and the network is not connected at every time instant but over\nsome finite time intervals. We provide a necessary and sufficient condition for\nthe rate at which agents decrease the weights and still guarantees social\nlearning.\n",
"title": "On Increasing Self-Confidence in Non-Bayesian Social Learning over Time-Varying Directed Graphs"
}
| null | null |
[
"Computer Science"
] | null | true | null |
4629
| null |
Validated
| null | null |
null |
{
"abstract": " Soft gamma repeaters and anomalous X-ray pulsars are thought to be magnetars,\nneutron stars with strong magnetic fields of order $\\mathord{\\sim}\n10^{13}$--$10^{15} \\, \\mathrm{gauss}$. These objects emit intermittent bursts\nof hard X-rays and soft gamma rays. Quasiperiodic oscillations in the X-ray\ntails of giant flares imply the existence of neutron star oscillation modes\nwhich could emit gravitational waves powered by the magnetar's magnetic energy\nreservoir. We describe a method to search for transient gravitational-wave\nsignals associated with magnetar bursts with durations of 10s to 1000s of\nseconds. The sensitivity of this method is estimated by adding simulated\nwaveforms to data from the sixth science run of Laser Interferometer\nGravitational-wave Observatory (LIGO). We find a search sensitivity in terms of\nthe root sum square strain amplitude of $h_{\\mathrm{rss}} = 1.3 \\times 10^{-21}\n\\, \\mathrm{Hz}^{-1/2}$ for a half sine-Gaussian waveform with a central\nfrequency $f_0 = 150 \\, \\mathrm{Hz}$ and a characteristic time $\\tau = 400 \\,\n\\mathrm{s}$. This corresponds to a gravitational wave energy of\n$E_{\\mathrm{GW}} = 4.3 \\times 10^{46} \\, \\mathrm{erg}$, the same order of\nmagnitude as the 2004 giant flare which had an estimated electromagnetic energy\nof $E_{\\mathrm{EM}} = \\mathord{\\sim} 1.7 \\times 10^{46} (d/ 8.7 \\,\n\\mathrm{kpc})^2 \\, \\mathrm{erg}$, where $d$ is the distance to SGR 1806-20. We\npresent an extrapolation of these results to Advanced LIGO, estimating a\nsensitivity to a gravitational wave energy of $E_{\\mathrm{GW}} = 3.2 \\times\n10^{43} \\, \\mathrm{erg}$ for a magnetar at a distance of $1.6 \\, \\mathrm{kpc}$.\nThese results suggest this search method can probe significantly below the\nenergy budgets for magnetar burst emission mechanisms such as crust cracking\nand hydrodynamic deformation.\n",
"title": "Exploring a search for long-duration transient gravitational waves associated with magnetar bursts"
}
| null | null |
[
"Physics"
] | null | true | null |
4630
| null |
Validated
| null | null |
null |
{
"abstract": " We report on the optical and mechanical characterization of arrays of\nparallel micromechanical membranes. Pairs of high-tensile stress, 100 nm-thick\nsilicon nitride membranes are assembled parallel with each other with\nseparations ranging from 8.5 to 200 $\\mu$m. Their optical properties are\naccurately determined using a combination of broadband and monochromatic\nilluminations and the lowest vibrational mode frequencies and mechanical\nquality factors are determined interferometrically. The results and techniques\ndemonstrated are promising for investigations of collective phenomena in\noptomechanical arrays.\n",
"title": "Optomechanical characterization of silicon nitride membrane arrays"
}
| null | null | null | null | true | null |
4631
| null |
Default
| null | null |
null |
{
"abstract": " The Prototypical magnetic memory shape alloy Ni$_2$MnGa undergoes various\nphase transitions as a function of temperature, pressure, and doping. In the\nlow-temperature phases below 260 K, an incommensurate structural modulation\noccurs along the [110] direction which is thought to arise from softening of a\nphonon mode. It is not at present clear how this phenomenon is related, if at\nall, to the magnetic memory effect. Here we report time-resolved measurements\nwhich track both the structural and magnetic components of the phase transition\nfrom the modulated cubic phase as it is brought into the high-symmetry phase.\nThe results suggest that the photoinduced demagnetization modifies the Fermi\nsurface in regions that couple strongly to the periodicity of the structural\nmodulation through the nesting vector. The amplitude of the periodic lattice\ndistortion, however, appears to be less affected by the demagnetizaton.\n",
"title": "Coupling between a charge density wave and magnetism in an Heusler material"
}
| null | null | null | null | true | null |
4632
| null |
Default
| null | null |
null |
{
"abstract": " FPGA-based heterogeneous architectures provide programmers with the ability\nto customize their hardware accelerators for flexible acceleration of many\nworkloads. Nonetheless, such advantages come at the cost of sacrificing\nprogrammability. FPGA vendors and researchers attempt to improve the\nprogrammability through high-level synthesis (HLS) technologies that can\ndirectly generate hardware circuits from high-level language descriptions.\nHowever, reading through recent publications on FPGA designs using HLS, one\noften gets the impression that FPGA programming is still hard in that it leaves\nprogrammers to explore a very large design space with many possible\ncombinations of HLS optimization strategies.\nIn this paper we make two important observations and contributions. First, we\ndemonstrate a rather surprising result: FPGA programming can be made easy by\nfollowing a simple best-effort guideline of five refinement steps using HLS. We\nshow that for a broad class of accelerator benchmarks from MachSuite, the\nproposed best-effort guideline improves the FPGA accelerator performance by\n42-29,030x. Compared to the baseline CPU performance, the FPGA accelerator\nperformance is improved from an average 292.5x slowdown to an average 34.4x\nspeedup. Moreover, we show that the refinement steps in the best-effort\nguideline, consisting of explicit data caching, customized pipelining,\nprocessing element duplication, computation/communication overlapping and\nscratchpad reorganization, correspond well to the best practice guidelines for\nmulticore CPU programming. Although our best-effort guideline may not always\nlead to the optimal solution, it substantially simplifies the FPGA programming\neffort, and will greatly support the wide adoption of FPGA-based acceleration\nby the software programming community.\n",
"title": "Best-Effort FPGA Programming: A Few Steps Can Go a Long Way"
}
| null | null | null | null | true | null |
4633
| null |
Default
| null | null |
null |
{
"abstract": " Penalized least squares estimation is a popular technique in high-dimensional\nstatistics. It includes such methods as the LASSO, the group LASSO, and the\nnuclear norm penalized least squares. The existing theory of these methods is\nnot fully satisfying since it allows one to prove oracle inequalities with\nfixed high probability only for the estimators depending on this probability.\nFurthermore, the control of compatibility factors appearing in the oracle\nbounds is often not explicit. Some very recent developments suggest that the\ntheory of oracle inequalities can be revised in an improved way. In this paper,\nwe provide an overview of ideas and tools leading to such an improved theory.\nWe show that, along with overcoming the disadvantages mentioned above, the\nmethodology extends to the hilbertian framework and it applies to a large class\nof convex penalties. This paper is partly expository. In particular, we provide\nadapted proofs of some results from other recent work.\n",
"title": "Towards the study of least squares estimators with convex penalty"
}
| null | null |
[
"Mathematics",
"Statistics"
] | null | true | null |
4634
| null |
Validated
| null | null |
null |
{
"abstract": " This paper proposes a novel semi-distributed and practical ICIC scheme based\non the Almost Blank SubFrame (ABSF) approach specified by 3GPP. We define two\nmathematical programming problems for the cases of guaranteed and best-effort\ntraffic, and use game theory to study the properties of the derived ICIC\ndistributed schemes, which are compared in detail against unaffordable\ncentralized schemes. Based on the analysis of the proposed models, we define\nDistributed Multi-traffic Scheduling (DMS), a unified distributed framework for\nadaptive interference-aware scheduling of base stations in future cellular\nnetworks which accounts for both guaranteed and best-effort traffic. DMS\nfollows a two-tier approach, consisting of local ABSF schedulers, which perform\nthe resource distribution between guaranteed and best effort traffic, and a\nlightweight local supervisor, which coordinates ABSF local decisions. As a\nresult of such a two-tier design, DMS requires very light signaling to drive\nthe local schedulers to globally efficient operating points. As shown by means\nof numerical results, DMS allows to (i) maximize radio resources reuse, (ii)\nprovide requested quality for guaranteed traffic, (iii) minimize the time\ndedicated to guaranteed traffic to leave room for best-effort traffic, and (iv)\nmaximize resource utilization efficiency for best-effort traffic.\n",
"title": "A Multi-traffic Inter-cell Interference Coordination Scheme in Dense Cellular Networks"
}
| null | null | null | null | true | null |
4635
| null |
Default
| null | null |
null |
{
"abstract": " We propose a framework for adversarial training that relies on a sample\nrather than a single sample point as the fundamental unit of discrimination.\nInspired by discrepancy measures and two-sample tests between probability\ndistributions, we propose two such distributional adversaries that operate and\npredict on samples, and show how they can be easily implemented on top of\nexisting models. Various experimental results show that generators trained with\nour distributional adversaries are much more stable and are remarkably less\nprone to mode collapse than traditional models trained with pointwise\nprediction discriminators. The application of our framework to domain\nadaptation also results in considerable improvement over recent\nstate-of-the-art.\n",
"title": "Distributional Adversarial Networks"
}
| null | null | null | null | true | null |
4636
| null |
Default
| null | null |
null |
{
"abstract": " The first order magneto-structural transition ($T_t\\simeq95$ K) and\nmagnetocaloric effect in MnNiGe$_{0.9}$Ga$_{0.1}$ are studied via powder x-ray\ndiffraction and magnetization measurements. Temperature dependent x-ray\ndiffraction measurements reveal that the magneto-structural transition remains\nincomplete down to 23 K, resulting in a coexistence of antiferromagnetic and\nferromagnetic phases at low temperatures. The fraction of the high temperature\nNi$_2$In-type hexagonal ferromagnetic and low temperature TiNiSi-type\northorhombic antiferromagnetic phases is estimated to be $\\sim 40\\%$ and $\\sim\n60\\%$, respectively at 23 K. The ferromagnetic phase fraction increases with\nincreasing field which is found to be in non-equilibrium state and gives rise\nto a weak re-entrant transition while warming under field-cooled condition. It\nshows a large inverse magnetocaloric effect across the magneto-structural\ntransition and a conventional magnetocaloric effect across the second order\nparamagnetic to ferromagnetic transition. The relative cooling power which\ncharacterizes the performance of a magnetic refrigerant material is found to be\nreasonably high compared to the other reported magnetocaloric alloys.\n",
"title": "First order magneto-structural transition and magnetocaloric effect in MnNiGe$_{0.9}$Ga$_{0.1}$"
}
| null | null | null | null | true | null |
4637
| null |
Default
| null | null |
null |
{
"abstract": " This work introduces the concept of parametric Gaussian processes (PGPs),\nwhich is built upon the seemingly self-contradictory idea of making Gaussian\nprocesses parametric. Parametric Gaussian processes, by construction, are\ndesigned to operate in \"big data\" regimes where one is interested in\nquantifying the uncertainty associated with noisy data. The proposed\nmethodology circumvents the well-established need for stochastic variational\ninference, a scalable algorithm for approximating posterior distributions. The\neffectiveness of the proposed approach is demonstrated using an illustrative\nexample with simulated data and a benchmark dataset in the airline industry\nwith approximately 6 million records.\n",
"title": "Parametric Gaussian Process Regression for Big Data"
}
| null | null | null | null | true | null |
4638
| null |
Default
| null | null |
null |
{
"abstract": " Discrimination-aware classification is receiving an increasing attention in\ndata science fields. The pre-process methods for constructing a\ndiscrimination-free classifier first remove discrimination from the training\ndata, and then learn the classifier from the cleaned data. However, they lack a\ntheoretical guarantee for the potential discrimination when the classifier is\ndeployed for prediction. In this paper, we fill this gap by mathematically\nbounding the probability of the discrimination in prediction being within a\ngiven interval in terms of the training data and classifier. We adopt the\ncausal model for modeling the data generation mechanism, and formally defining\ndiscrimination in population, in a dataset, and in prediction. We obtain two\nimportant theoretical results: (1) the discrimination in prediction can still\nexist even if the discrimination in the training data is completely removed;\nand (2) not all pre-process methods can ensure non-discrimination in prediction\neven though they can achieve non-discrimination in the modified training data.\nBased on the results, we develop a two-phase framework for constructing a\ndiscrimination-free classifier with a theoretical guarantee. The experiments\ndemonstrate the theoretical results and show the effectiveness of our two-phase\nframework.\n",
"title": "Achieving non-discrimination in prediction"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
4639
| null |
Validated
| null | null |
null |
{
"abstract": " A set of points a 1 ,. .. , a n fixes a planar convex body K if the points\nare on bdK, the boundary of K, and if any small move of K brings some point of\nthe set in intK, the interior of K. The points a 1 ,. .. , a n $\\in$ bdK almost\nfix K if, for any neighbourhoods V i of a i (i = 1,. .. , n), there are pairs\nof points a i , a i $\\in$ V i $\\cap$ bdK such that a 1 , a 1 ,. .. , a n fix K.\nThis note compares several definitions of these notions and gives first order\nconditions for a 1 ,. .. , a n $\\in$ bdK to fix, and to almost fix, K.\n",
"title": "Fixing and almost fixing a planar convex body"
}
| null | null | null | null | true | null |
4640
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we consider prior-based dimension reduction Kalman filter for\nundersampled dynamic X-ray tomography. With this method, the X-ray\nreconstructions are parameterized by a low-dimensional basis. Thus, the\nproposed method is a) computationally very light; and b) extremely robust as\nall the computations can be done explicitly. With real and simulated\nmeasurement data, we show that the method provides accurate reconstructions\neven with very limited number of angular directions.\n",
"title": "Undersampled dynamic X-ray tomography with dimension reduction Kalman filter"
}
| null | null |
[
"Statistics"
] | null | true | null |
4641
| null |
Validated
| null | null |
null |
{
"abstract": " Can we perform an end-to-end sound source separation (SSS) with a variable\nnumber of sources using a deep learning model? This paper presents an extension\nof the Wave-U-Net model which allows end-to-end monaural source separation with\na non-fixed number of sources. Furthermore, we propose multiplicative\nconditioning with instrument labels at the bottleneck of the Wave-U-Net and\nshow its effect on the separation results. This approach can be further\nextended to other types of conditioning such as audio-visual SSS and\nscore-informed SSS.\n",
"title": "End-to-End Sound Source Separation Conditioned On Instrument Labels"
}
| null | null | null | null | true | null |
4642
| null |
Default
| null | null |
null |
{
"abstract": " The complete group classification problem for the class of (1+1)-dimensional\n$r$th order general variable-coefficient Burgers-Korteweg-de Vries equations is\nsolved for arbitrary values of $r$ greater than or equal to two. We find the\nequivalence groupoids of this class and its various subclasses obtained by\ngauging equation coefficients with equivalence transformations. Showing that\nthis class and certain gauged subclasses are normalized in the usual sense, we\nreduce the complete group classification problem for the entire class to that\nfor the selected maximally gauged subclass, and it is the latter problem that\nis solved efficiently using the algebraic method of group classification.\nSimilar studies are carried out for the two subclasses of equations with\ncoefficients depending at most on the time or space variable, respectively.\nApplying an original technique, we classify Lie reductions of equations from\nthe class under consideration with respect to its equivalence group. Studying\nof alternative gauges for equation coefficients with equivalence\ntransformations allows us not only to justify the choice of the most\nappropriate gauge for the group classification but also to construct for the\nfirst time classes of differential equations with nontrivial generalized\nequivalence group such that equivalence-transformation components corresponding\nto equation variables locally depend on nonconstant arbitrary elements of the\nclass. For the subclass of equations with coefficients depending at most on the\ntime variable, which is normalized in the extended generalized sense, we\nexplicitly construct its extended generalized equivalence group in a rigorous\nway. The new notion of effective generalized equivalence group is introduced.\n",
"title": "Group analysis of general Burgers-Korteweg-de Vries equations"
}
| null | null | null | null | true | null |
4643
| null |
Default
| null | null |
null |
{
"abstract": " Generative adversarial networks (GAN) have been effective for learning\ngenerative models for real-world data. However, existing GANs (GAN and its\nvariants) tend to suffer from training problems such as instability and mode\ncollapse. In this paper, we propose a novel GAN framework called evolutionary\ngenerative adversarial networks (E-GAN) for stable GAN training and improved\ngenerative performance. Unlike existing GANs, which employ a pre-defined\nadversarial objective function alternately training a generator and a\ndiscriminator, we utilize different adversarial training objectives as mutation\noperations and evolve a population of generators to adapt to the environment\n(i.e., the discriminator). We also utilize an evaluation mechanism to measure\nthe quality and diversity of generated samples, such that only well-performing\ngenerator(s) are preserved and used for further training. In this way, E-GAN\novercomes the limitations of an individual adversarial training objective and\nalways preserves the best offspring, contributing to progress in and the\nsuccess of GANs. Experiments on several datasets demonstrate that E-GAN\nachieves convincing generative performance and reduces the training problems\ninherent in existing GANs.\n",
"title": "Evolutionary Generative Adversarial Networks"
}
| null | null | null | null | true | null |
4644
| null |
Default
| null | null |
null |
{
"abstract": " Smartphones have ubiquitously integrated into our home and work environments,\nhowever, users normally rely on explicit but inefficient identification\nprocesses in a controlled environment. Therefore, when a device is stolen, a\nthief can have access to the owner's personal information and services against\nthe stored password/s. As a result of this potential scenario, this work\ndemonstrates the possibilities of legitimate user identification in a\nsemi-controlled environment through the built-in smartphones motion dynamics\ncaptured by two different sensors. This is a two-fold process: sub-activity\nrecognition followed by user/impostor identification. Prior to the\nidentification; Extended Sammon Projection (ESP) method is used to reduce the\nredundancy among the features. To validate the proposed system, we first\ncollected data from four users walking with their device freely placed in one\nof their pants pockets. Through extensive experimentation, we demonstrate that\ntogether time and frequency domain features optimized by ESP to train the\nwavelet kernel based extreme learning machine classifier is an effective system\nto identify the legitimate user or an impostor with \\(97\\%\\) accuracy.\n",
"title": "Extended Sammon Projection and Wavelet Kernel Extreme Learning Machine for Gait-Based Legitimate User Identification on Smartphones"
}
| null | null | null | null | true | null |
4645
| null |
Default
| null | null |
null |
{
"abstract": " We consider the distribution of free path lengths, or the distance between\nconsecutive bounces of random particles, in an n-dimensional rectangular box.\nIf each particle travels a distance R, then, as R tends to infinity the free\npath lengths coincides with the distribution of the length of the intersection\nof a random line with the box (for a natural ensemble of random lines) and we\ngive an explicit formula (piecewise real analytic) for the probability density\nfunction in dimension two and three.\nIn dimension two we also consider a closely related model where each particle\nis allowed to bounce N times, as N tends to infinity, and give an explicit\n(again piecewise real analytic) formula for its probability density function.\nFurther, in both models we can recover the side lengths of the box from the\nlocation of the discontinuities of the probability density functions.\n",
"title": "On the free path length distribution for linear motion in an n-dimensional box"
}
| null | null | null | null | true | null |
4646
| null |
Default
| null | null |
null |
{
"abstract": " We present measurements of the spin-orbit misalignments of the hot Jupiters\nHAT-P-41 b and WASP-79 b, and the aligned warm Jupiter Kepler-448 b. We\nobtained these measurements with Doppler tomography, where we spectroscopically\nresolve the line profile perturbation during the transit due to the\nRossiter-McLaughlin effect. We analyze time series spectra obtained during\nportions of five transits of HAT-P-41 b, and find a value of the spin-orbit\nmisalignment of $\\lambda = -22.1_{-6.0}^{+0.8 \\circ}$. We reanalyze the radial\nvelocity Rossiter-McLaughlin data on WASP-79 b obtained by Addison et al.\n(2013) using Doppler tomographic methodology. We measure\n$\\lambda=-99.1_{-3.9}^{+4.1\\circ}$, consistent with but more precise than the\nvalue found by Addison et al. (2013). For Kepler-448 b we perform a joint fit\nto the Kepler light curve, Doppler tomographic data, and a radial velocity\ndataset from Lillo-Box et al. (2015). We find an approximately aligned orbit\n($\\lambda=-7.1^{+4.2 \\circ}_{-2.8}$), in modest disagreement with the value\nfound by Bourrier et al. (2015). Through analysis of the Kepler light curve we\nmeasure a stellar rotation period of $P_{\\mathrm{rot}}=1.27 \\pm 0.11$ days, and\nuse this to argue that the full three-dimensional spin-orbit misalignment is\nsmall, $\\psi\\sim0^{\\circ}$.\n",
"title": "Spin-Orbit Misalignments of Three Jovian Planets via Doppler Tomography"
}
| null | null | null | null | true | null |
4647
| null |
Default
| null | null |
null |
{
"abstract": " This paper introduces a novel parameter estimation method for the probability\ntables of Bayesian network classifiers (BNCs), using hierarchical Dirichlet\nprocesses (HDPs). The main result of this paper is to show that improved\nparameter estimation allows BNCs to outperform leading learning methods such as\nRandom Forest for both 0-1 loss and RMSE, albeit just on categorical datasets.\nAs data assets become larger, entering the hyped world of \"big\", efficient\naccurate classification requires three main elements: (1) classifiers with\nlow-bias that can capture the fine-detail of large datasets (2) out-of-core\nlearners that can learn from data without having to hold it all in main memory\nand (3) models that can classify new data very efficiently.\nThe latest Bayesian network classifiers (BNCs) satisfy these requirements.\nTheir bias can be controlled easily by increasing the number of parents of the\nnodes in the graph. Their structure can be learned out of core with a limited\nnumber of passes over the data. However, as the bias is made lower to\naccurately model classification tasks, so is the accuracy of their parameters'\nestimates, as each parameter is estimated from ever decreasing quantities of\ndata. In this paper, we introduce the use of Hierarchical Dirichlet Processes\nfor accurate BNC parameter estimation.\nWe conduct an extensive set of experiments on 68 standard datasets and\ndemonstrate that our resulting classifiers perform very competitively with\nRandom Forest in terms of prediction, while keeping the out-of-core capability\nand superior classification time.\n",
"title": "Accurate parameter estimation for Bayesian Network Classifiers using Hierarchical Dirichlet Processes"
}
| null | null | null | null | true | null |
4648
| null |
Default
| null | null |
null |
{
"abstract": " This paper applies the multibond graph approach for rigid multibody systems\nto model the dynamics of general spatial mechanisms. The commonly used quick\nreturn mechanism which comprises of revolute as well as prismatic joints has\nbeen chosen as a representative example to demonstrate the application of this\ntechnique and its resulting advantages. In this work, the links of the quick\nreturn mechanism are modeled as rigid bodies. The rigid links are then coupled\nat the joints based on the nature of constraint. This alternative method of\nformulation of system dynamics, using Bond Graphs, offers a rich set of\nfeatures that include pictorial representation of the dynamics of translation\nand rotation for each link of the mechanism in the inertial frame,\nrepresentation and handling of constraints at the joints, depiction of\ncausality, obtaining dynamic reaction forces and moments at various locations\nin the mechanism and so on. Yet another advantage of this approach is that the\ncoding for simulation can be carried out directly from the Bond Graph in an\nalgorithmic manner, without deriving system equations. In this work, the\nprogram code for simulation is written in MATLAB. The vector and tensor\noperations are conveniently represented in MATLAB, resulting in a compact and\noptimized code. The simulation results are plotted and discussed in detail.\n",
"title": "Modeling and Simulation of the Dynamics of the Quick Return Mechanism: A Bond Graph Approach"
}
| null | null | null | null | true | null |
4649
| null |
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| null | null |
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{
"abstract": " Nauticle is a general-purpose simulation tool for the flexible and highly\nconfigurable application of particle-based methods of either discrete or\ncontinuum phenomena. It is presented that Nauticle has three distinct layers\nfor users and developers, then the top two layers are discussed in detail. The\npaper introduces the Symbolic Form Language (SFL) of Nauticle, which\nfacilitates the formulation of user-defined numerical models at the top level\nin text-based configuration files and provides simple application examples of\nuse. On the other hand, at the intermediate level, it is shown that the SFL can\nbe intuitively extended with new particle methods without tedious recoding or\neven the knowledge of the bottom level. Finally, the efficiency of the code is\nalso tested through a performance benchmark.\n",
"title": "Nauticle: a general-purpose particle-based simulation tool"
}
| null | null | null | null | true | null |
4650
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| null | null |
null |
{
"abstract": " Below the phase transition temperature $Tc \\simeq 10^{-3}$K He-3B has a\nmixture of normal and superfluid components. Turbulence in this material is\ncarried predominantly by the superfluid component. We explore the statistical\nproperties of this quantum turbulence, stressing the differences from the\nbetter known classical counterpart. To this aim we study the time-honored\nHall-Vinen-Bekarevich-Khalatnikov coarse-grained equations of superfluid\nturbulence. We combine pseudo-spectral direct numerical simulations with\nanalytic considerations based on an integral closure for the energy flux. We\navoid the assumption of locality of the energy transfer which was used\npreviously in both analytic and numerical studies of the superfluid He-3B\nturbulence. For T<0.37 Tc, with relatively weak mutual friction, we confirm the\npreviously found \"subcritical\" energy spectrum E(k), given by a superposition\nof two power laws that can be approximated as $E(k)~ k^{-x}$ with an apparent\nscaling exponent 5/3 <x(k)< 3. For T>0.37 Tc and with strong mutual friction,\nwe observed numerically and confirmed analytically the scale-invariant spectrum\n$E(k)~ k^{-x}$ with a (k-independent) exponent x > 3 that gradually increases\nwith the temperature and reaches a value $x\\simeq 9$ for $T\\approx 0.72 Tc$. In\nthe near-critical regimes we discover a strong enhancement of intermittency\nwhich exceeds by an order of magnitude the corresponding level in classical\nhydrodynamic turbulence.\n",
"title": "Local and non-local energy spectra of superfluid $^3$He turbulence"
}
| null | null | null | null | true | null |
4651
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| null | null |
null |
{
"abstract": " Key performance characteristics are demonstrated for the microwave SQUID\nmultiplexer ($\\mu$MUX) coupled to transition edge sensor (TES) bolometers that\nhave been optimized for cosmic microwave background (CMB) observations. In a\n64-channel demonstration, we show that the $\\mu$MUX produces a white, input\nreferred current noise level of 29~pA$/\\sqrt{\\mathrm{Hz}}$ at -77~dB microwave\nprobe tone power, which is well below expected fundamental detector and photon\nnoise sources for a ground-based CMB-optimized bolometer. Operated with\nnegligible photon loading, we measure 98~pA$/\\sqrt{\\mathrm{Hz}}$ in the\nTES-coupled channels biased at 65% of the sensor normal resistance. This noise\nlevel is consistent with that predicted from bolometer thermal fluctuation\n(i.e., phonon) noise. Furthermore, the power spectral density exhibits a white\nspectrum at low frequencies ($\\sim$~100~mHz), which enables CMB mapping on\nlarge angular scales that constrain the physics of inflation. Additionally, we\nreport cross-talk measurements that indicate a level below 0.3%, which is less\nthan the level of cross-talk from multiplexed readout systems in deployed CMB\nimagers. These measurements demonstrate the $\\mu$MUX as a viable readout\ntechnique for future CMB imaging instruments.\n",
"title": "Microwave SQUID Multiplexer demonstration for Cosmic Microwave Background Imagers"
}
| null | null | null | null | true | null |
4652
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| null | null |
null |
{
"abstract": " Privacy is crucial in many applications of machine learning. Legal, ethical\nand societal issues restrict the sharing of sensitive data making it difficult\nto learn from datasets that are partitioned between many parties. One important\ninstance of such a distributed setting arises when information about each\nrecord in the dataset is held by different data owners (the design matrix is\n\"vertically-partitioned\").\nIn this setting few approaches exist for private data sharing for the\npurposes of statistical estimation and the classical setup of differential\nprivacy with a \"trusted curator\" preparing the data does not apply. We work\nwith the notion of $(\\epsilon,\\delta)$-distributed differential privacy which\nextends single-party differential privacy to the distributed,\nvertically-partitioned case. We propose PriDE, a scalable framework for\ndistributed estimation where each party communicates perturbed random\nprojections of their locally held features ensuring\n$(\\epsilon,\\delta)$-distributed differential privacy is preserved. For\n$\\ell_2$-penalized supervised learning problems PriDE has bounded estimation\nerror compared with the optimal estimates obtained without privacy constraints\nin the non-distributed setting. We confirm this empirically on real world and\nsynthetic datasets.\n",
"title": "Preserving Differential Privacy Between Features in Distributed Estimation"
}
| null | null | null | null | true | null |
4653
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| null | null |
null |
{
"abstract": " This research presents a model of a complex dynamic object running on a\nmulti-core system. Discretization and numerical integration for multibody\nmodels of vehicle rail elements in the vertical longitudinal plane fluctuations\nis considered. The implemented model and solution of the motion differential\nequations allow estimating the basic processes occurring in the system with\nvarious external influences. Hence the developed programming model can be used\nfor performing analysis and comparing new vehicle designs.\nKeywords-dynamic model; multi-core system; SMP system; rolling stock.\n",
"title": "Parallel implementation of a vehicle rail dynamical model for multi-core systems"
}
| null | null | null | null | true | null |
4654
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| null | null |
null |
{
"abstract": " In this paper, we present Neural Phrase-based Machine Translation (NPMT). Our\nmethod explicitly models the phrase structures in output sequences using\nSleep-WAke Networks (SWAN), a recently proposed segmentation-based sequence\nmodeling method. To mitigate the monotonic alignment requirement of SWAN, we\nintroduce a new layer to perform (soft) local reordering of input sequences.\nDifferent from existing neural machine translation (NMT) approaches, NPMT does\nnot use attention-based decoding mechanisms. Instead, it directly outputs\nphrases in a sequential order and can decode in linear time. Our experiments\nshow that NPMT achieves superior performances on IWSLT 2014\nGerman-English/English-German and IWSLT 2015 English-Vietnamese machine\ntranslation tasks compared with strong NMT baselines. We also observe that our\nmethod produces meaningful phrases in output languages.\n",
"title": "Towards Neural Phrase-based Machine Translation"
}
| null | null | null | null | true | null |
4655
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| null | null |
null |
{
"abstract": " We propose a method for multi-person detection and 2-D pose estimation that\nachieves state-of-art results on the challenging COCO keypoints task. It is a\nsimple, yet powerful, top-down approach consisting of two stages.\nIn the first stage, we predict the location and scale of boxes which are\nlikely to contain people; for this we use the Faster RCNN detector. In the\nsecond stage, we estimate the keypoints of the person potentially contained in\neach proposed bounding box. For each keypoint type we predict dense heatmaps\nand offsets using a fully convolutional ResNet. To combine these outputs we\nintroduce a novel aggregation procedure to obtain highly localized keypoint\npredictions. We also use a novel form of keypoint-based Non-Maximum-Suppression\n(NMS), instead of the cruder box-level NMS, and a novel form of keypoint-based\nconfidence score estimation, instead of box-level scoring.\nTrained on COCO data alone, our final system achieves average precision of\n0.649 on the COCO test-dev set and the 0.643 test-standard sets, outperforming\nthe winner of the 2016 COCO keypoints challenge and other recent state-of-art.\nFurther, by using additional in-house labeled data we obtain an even higher\naverage precision of 0.685 on the test-dev set and 0.673 on the test-standard\nset, more than 5% absolute improvement compared to the previous best performing\nmethod on the same dataset.\n",
"title": "Towards Accurate Multi-person Pose Estimation in the Wild"
}
| null | null | null | null | true | null |
4656
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| null | null |
null |
{
"abstract": " We combine space group representation theory together with scanning of closed\nsubdomains of the Brillouin zone with Wilson loops to algebraically determine\nglobal band structure topology. Considering space group #19 as a case study, we\nshow that the energy ordering of the irreducible representations at the\nhigh-symmetry points $\\{\\Gamma,S,T,U\\}$ fully determines the global band\ntopology, with all topological classes characterized through their simple and\ndouble Dirac-points.\n",
"title": "Global band topology of simple and double Dirac-point (semi-)metals"
}
| null | null | null | null | true | null |
4657
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| null | null |
null |
{
"abstract": " In statistics cumulants are defined to be functions that measure the linear\nindependence of random variables. In the non-communicative case the Boolean\ncumulants can be described as functions that measure deviation of a map between\nalgebras from being an algebra morphism. In Algebraic topology maps that are\nhomotopic to being algebra morphisms are studied using the theory of $A_\\infty$\nalgebras. In this paper we will explore the link between these two points of\nviews on maps between algebras that are not algebra maps.\n",
"title": "Topological Perspectives on Statistical Quantities I"
}
| null | null | null | null | true | null |
4658
| null |
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| null | null |
null |
{
"abstract": " A freely available Python code for modelling SNR evolution has been created.\nThis software is intended for two purposes: to understand SNR evolution; and to\nuse in modelling observations of SNR for obtaining good estimates of SNR\nproperties. It includes all phases for the standard path of evolution for\nspherically symmetric SNRs. In addition, alternate evolutionary models are\navailable, including evolution in a cloudy ISM, the fractional energy loss\nmodel, and evolution in a hot low-density ISM. The graphical interface takes in\nvarious parameters and produces outputs such as shock radius and velocity vs.\ntime, SNR surface brightness profile and spectrum. Some interesting properties\nof SNR evolution are demonstrated using the program.\n",
"title": "A Python Calculator for Supernova Remnant Evolution"
}
| null | null | null | null | true | null |
4659
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| null | null |
null |
{
"abstract": " In this work, we examine two approaches to interprocedural data-flow analysis\nof Sharir and Pnueli in terms of precision: the functional and the call-string\napproach. In doing so, not only the theoretical best, but all solutions are\nregarded which occur when using abstract interpretation or widening\nadditionally. It turns out that the solutions of both approaches coincide. This\nproperty is preserved when using abstract interpretation; in the case of\nwidening, a comparison of the results is not always possible.\n",
"title": "Über die Präzision interprozeduraler Analysen"
}
| null | null | null | null | true | null |
4660
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| null | null |
null |
{
"abstract": " Gee-Haw Whammy Diddle is a seemingly simple mechanical toy consisting of a\nwooden stick and a second stick that is made up of a series of notches with a\npropeller at its end. When the wooden stick is pulled over the notches, the\npropeller starts to rotate. In spite of its simplicity, physical principles\ngoverning the motion of the stick and the propeller are rather complicated and\ninteresting. Here we provide a thorough analysis of the system and parameters\ninfluencing the motion. We show that contrary to the results published on this\ntopic so far, neither elliptic motion of the stick nor frequency\nsynchronization is needed for starting the motion of the propeller.\n",
"title": "Gee-Haw Whammy Diddle"
}
| null | null | null | null | true | null |
4661
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| null | null |
null |
{
"abstract": " The cancellation theorem for Grothendieck-Witt-correspondences and\nWitt-correspondences between smooth varieties over an infinite prefect field\n$k$, $char k \\neq 2$, is proved, the isomorphism\n$$Hom_{\\mathbf{DM}^\\mathrm{GW}_\\mathrm{eff}}(A^\\bullet,B^\\bullet) \\simeq\nHom_{\\mathbf{DM}^\\mathrm{GW}_\\mathrm{eff}}(A^\\bullet(1),B^\\bullet(1)),$$ for\n$A^\\bullet,B^\\bullet\\in \\mathbf{DM}^\\mathrm{GW}_\\mathrm{eff}(k)$ in the\ncategory of effective Grothendieck-Witt-motives constructed in\n\\cite{AD_DMGWeff} is obtained (and similarly for Witt-motives).\nThis implies that the canonical functor $\\Sigma_{\\mathbb G_m^{\\wedge\n1}}^\\infty\\colon \\mathbf{DM}^\\mathrm{GW}_\\mathrm{eff}(k)\\to\n\\mathbf{DM}^\\mathrm{GW}(k)$ is fully faithful, where\n$\\mathbf{DM}^\\mathrm{GW}(k)$ is the category of non-effective GW-motives\n(defined by stabilization of $\\mathbf{DM}^\\mathrm{GW}_\\mathrm{eff}(k)$ along\n$\\mathbb G_m^{\\wedge 1}$) and yields the main property of motives of smooth\nvarieties in the category $\\mathbf{DM}^\\mathrm{GW}(k)$: $$\nHom_{\\mathbf{DM}^\\mathrm{GW}(k)}(M^{GW}(X), \\Sigma_{\\mathbb G_m^{\\wedge\n1}}^\\infty\\mathcal F[i]) \\simeq H^i_{Nis}(X,\\mathcal F) ,$$ for any smooth\nvariety $X$ and homotopy invariant sheave with GW-transfers $\\mathcal F$ (and\nsimilarly for $\\mathbf{DM}^\\mathrm{W}(k)$).\n",
"title": "Cancellation theorem for Grothendieck-Witt-correspondences and Witt-correspondences"
}
| null | null | null | null | true | null |
4662
| null |
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| null | null |
null |
{
"abstract": " Motivation: The rapid growth of diverse biological data allows us to consider\ninteractions between a variety of objects, such as genes, chemicals, molecular\nsignatures, diseases, pathways and environmental exposures. Often, any pair of\nobjects--such as a gene and a disease--can be related in different ways, for\nexample, directly via gene-disease associations or indirectly via functional\nannotations, chemicals and pathways. Different ways of relating these objects\ncarry different semantic meanings. However, traditional methods disregard these\nsemantics and thus cannot fully exploit their value in data modeling.\nResults: We present Medusa, an approach to detect size-k modules of objects\nthat, taken together, appear most significant to another set of objects. Medusa\noperates on large-scale collections of heterogeneous data sets and explicitly\ndistinguishes between diverse data semantics. It advances research along two\ndimensions: it builds on collective matrix factorization to derive different\nsemantics, and it formulates the growing of the modules as a submodular\noptimization program. Medusa is flexible in choosing or combining semantic\nmeanings and provides theoretical guarantees about detection quality. In a\nsystematic study on 310 complex diseases, we show the effectiveness of Medusa\nin associating genes with diseases and detecting disease modules. We\ndemonstrate that in predicting gene-disease associations Medusa compares\nfavorably to methods that ignore diverse semantic meanings. We find that the\nutility of different semantics depends on disease categories and that, overall,\nMedusa recovers disease modules more accurately when combining different\nsemantics.\n",
"title": "Jumping across biomedical contexts using compressive data fusion"
}
| null | null | null | null | true | null |
4663
| null |
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| null | null |
null |
{
"abstract": " While I was dealing with a brain injury and finding it difficult to work, two\nfriends (Derek Westen, a friend of the KITP, and Steve Shenker, with whom I was\nrecently collaborating), suggested that a new direction might be good. Steve in\nparticular regarded me as a good writer and suggested that I try that. I\nquickly took to Steve's suggestion. Having only two bodies of knowledge, myself\nand physics, I decided to write an autobiography about my development as a\ntheoretical physicist.\nThis is not written for any particular audience, but just to give myself a\ngoal. It will probably have too much physics for a nontechnical reader, and too\nlittle for a physicist, but perhaps there with be different things for each.\nParts may be tedious. But it is somewhat unique, I think, a blow-by-blow\nhistory of where I started and where I got to.\nProbably the target audience is theoretical physicists, especially young\nones, who may enjoy comparing my struggles with their own. Some disclaimers:\nThis is based on my own memories, jogged by the arXiv and Inspire. There will\nsurely be errors and omissions. And note the title: this is about my memories,\nwhich will be different for other people. Also, it would not be possible for me\nto mention all the authors whose work might intersect mine, so this should not\nbe treated as a reference work.\n",
"title": "Memories of a Theoretical Physicist"
}
| null | null | null | null | true | null |
4664
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| null | null |
null |
{
"abstract": " Rapid changes in extracellular osmolarity are one of many insults microbial\ncells face on a daily basis. To protect against such shocks, Escherichia coli\nand other microbes express several types of transmembrane channels which open\nand close in response to changes in membrane tension. In E. coli, one of the\nmost abundant channels is the mechanosensitive channel of large conductance\n(MscL). While this channel has been heavily characterized through structural\nmethods, electrophysiology, and theoretical modeling, our understanding of its\nphysiological role in preventing cell death by alleviating high membrane\ntension remains tenuous. In this work, we examine the contribution of MscL\nalone to cell survival after osmotic shock at single cell resolution using\nquantitative fluorescence microscopy. We conduct these experiments in an E.\ncoli strain which is lacking all mechanosensitive channel genes save for MscL\nwhose expression is tuned across three orders of magnitude through\nmodifications of the Shine-Dalgarno sequence. While theoretical models suggest\nthat only a few MscL channels would be needed to alleviate even large changes\nin osmotic pressure, we find that between 500 and 700 channels per cell are\nneeded to convey upwards of 80% survival. This number agrees with the average\nMscL copy number measured in wild-type E. coli cells through proteomic studies\nand quantitative Western blotting. Furthermore, we observe zero survival events\nin cells with less than 100 channels per cell. This work opens new questions\nconcerning the contribution of other mechanosensitive channels to survival as\nwell as regulation of their activity.\n",
"title": "Connecting the dots between mechanosensitive channel abundance, osmotic shock, and survival at single-cell resolution"
}
| null | null | null | null | true | null |
4665
| null |
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| null | null |
null |
{
"abstract": " We present an optical mapping near-eye (OMNI) three-dimensional display\nmethod for wearable devices. By dividing a display screen into different\nsub-panels and optically mapping them to various depths, we create a multiplane\nvolumetric image with correct focus cues for depth perception. The resultant\nsystem can drive the eye's accommodation to the distance that is consistent\nwith binocular stereopsis, thereby alleviating the vergence-accommodation\nconflict, the primary cause for eye fatigue and discomfort. Compared with the\nprevious methods, the OMNI display offers prominent advantages in adaptability,\nimage dynamic range, and refresh rate.\n",
"title": "Optical Mapping Near-eye Three-dimensional Display with Correct Focus Cues"
}
| null | null | null | null | true | null |
4666
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| null | null |
null |
{
"abstract": " Topological phases typically encode topology at the level of the single\nparticle band structure. But a remarkable class of models shows that quantum\nanomalous Hall effects can be driven exclusively by interactions, while the\nparent non-interacting band structure is topologically trivial. Unfortunately,\nthese models have so far relied on interactions that do not spatially decay and\nare therefore unphysical. We study a model of spinless fermions on a decorated\nhoneycomb lattice. Using complementary methods, mean-field theory and exact\ndiagonalization, we find a robust quantum anomalous Hall phase arising from\nspatially decaying interactions. Our finding paves the way for observing the\nquantum anomalous Hall effect driven entirely by interactions.\n",
"title": "Quantum anomalous Hall state from spatially decaying interactions on the decorated honeycomb lattice"
}
| null | null |
[
"Physics"
] | null | true | null |
4667
| null |
Validated
| null | null |
null |
{
"abstract": " We introduce a new dynamical system for sequentially observed multivariate\ncount data. This model is based on the gamma--Poisson construction---a natural\nchoice for count data---and relies on a novel Bayesian nonparametric prior that\nties and shrinks the model parameters, thus avoiding overfitting. We present an\nefficient MCMC inference algorithm that advances recent work on augmentation\nschemes for inference in negative binomial models. Finally, we demonstrate the\nmodel's inductive bias using a variety of real-world data sets, showing that it\nexhibits superior predictive performance over other models and infers highly\ninterpretable latent structure.\n",
"title": "Poisson--Gamma Dynamical Systems"
}
| null | null | null | null | true | null |
4668
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| null | null |
null |
{
"abstract": " Incremental methods for structure learning of pairwise Markov random fields\n(MRFs), such as grafting, improve scalability by avoiding inference over the\nentire feature space in each optimization step. Instead, inference is performed\nover an incrementally grown active set of features. In this paper, we address\nkey computational bottlenecks that current incremental techniques still suffer\nby introducing best-choice edge grafting, an incremental, structured method\nthat activates edges as groups of features in a streaming setting. The method\nuses a reservoir of edges that satisfy an activation condition, approximating\nthe search for the optimal edge to activate. It also reorganizes the search\nspace using search-history and structure heuristics. Experiments show a\nsignificant speedup for structure learning and a controllable trade-off between\nthe speed and quality of learning.\n",
"title": "Best-Choice Edge Grafting for Efficient Structure Learning of Markov Random Fields"
}
| null | null | null | null | true | null |
4669
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{
"abstract": " We theoretically investigate charge transport through electronic bands of a\nmesoscopic one-dimensional system, where inter-band transitions are coupled to\na confined cavity mode, initially prepared close to its vacuum. This coupling\nleads to light-matter hybridization where the dressed fermionic bands interact\nvia absorption and emission of dressed cavity-photons. Using a self-consistent\nnon-equilibrium Green's function method, we compute electronic transmissions\nand cavity photon spectra and demonstrate how light-matter coupling can lead to\nan enhancement of charge conductivity in the steady-state. We find that\ndepending on cavity loss rate, electronic bandwidth, and coupling strength, the\ndynamics involves either an individual or a collective response of Bloch\nstates, and explain how this affects the current enhancement. We show that the\ncharge conductivity enhancement can reach orders of magnitudes under\nexperimentally relevant conditions.\n",
"title": "Cavity-enhanced transport of charge"
}
| null | null | null | null | true | null |
4670
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{
"abstract": " In this paper, I study the isoparametric hypersurfaces in a Randers sphere\n$(S^n,F)$ of constant flag curvature, with the navigation datum $(h,W)$. I\nprove that an isoparametric hypersurface $M$ for the standard round sphere\n$(S^n,h)$ which is tangent to $W$ remains isoparametric for $(S^n,F)$ after the\nnavigation process. This observation provides a special class of isoparametric\nhypersurfaces in $(S^n,F)$, which can be equivalently described as the regular\nlevel sets of isoparametric functions $f$ satisfying $-f$ is transnormal. I\nprovide a classification for these special isoparametric hypersurfaces $M$,\ntogether with their ambient metric $F$ on $S^n$, except the case that $M$ is of\nthe OT-FKM type with the multiplicities $(m_1,m_2)=(8,7)$. I also give a\ncomplete classificatoin for all homogeneous hypersurfaces in $(S^n,F)$. They\nall belong to these special isoparametric hypersurfaces. Because of the extra\n$W$, the number of distinct principal curvature can only be 1,2 or 4, i.e.\nthere are less homogeneous hypersurfaces for $(S^n,F)$ than those for\n$(S^n,h)$.\n",
"title": "Isoparameteric hypersurfaces in a Randers sphere of constant flag curvature"
}
| null | null | null | null | true | null |
4671
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| null | null |
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{
"abstract": " Formation of a bright-field microscopic image of a transparent phase object\nis described in terms of elementary geometrical optics. Our approach is based\non the premise that image replicates the intensity distribution (real or\nvirtual) at the front focal plane of the objective. The task is therefore\nreduced to finding the change in intensity at the focal plane caused by the\nobject. This can be done by ray tracing complemented with the requirement of\nconservation of the number of rays. Despite major simplifications involved in\nsuch an analysis, it reproduces some results from the paraxial wave theory.\nAdditionally, our analysis suggests two ways of extracting quantitative phase\ninformation from bright-field images: by vertically shifting the focal plane\n(the approach used in the transport-of-intensity analysis) or by varying the\nangle of illumination. In principle, information thus obtained should allow\nreconstruction of the object morphology.\n",
"title": "Bright-field microscopy of transparent objects: a ray tracing approach"
}
| null | null |
[
"Physics"
] | null | true | null |
4672
| null |
Validated
| null | null |
null |
{
"abstract": " The actin cytoskeleton is an active semi-flexible polymer network whose\nnon-equilibrium properties coordinate both stable and contractile behaviors to\nmaintain or change cell shape. While myosin motors drive the actin cytoskeleton\nout-of-equilibrium, the role of myosin-driven active stresses in the\naccumulation and dissipation of mechanical energy is unclear. To investigate\nthis, we synthesize an actomyosin material in vitro whose active stress content\ncan tune the network from stable to contractile. Each increment in activity\ndetermines a characteristic spectrum of actin filament fluctuations which is\nused to calculate the total mechanical work and the production of entropy in\nthe material. We find that the balance of work and entropy does not increase\nmonotonically and, surprisingly, the entropy production rate is maximized in\nthe non-contractile, stable state. Our study provides evidence that the origins\nof system entropy production and activity-dependent dissipation arise from\ndisorder in the molecular interactions between actin and myosin\n",
"title": "Entropy Production Rate is Maximized in Non-Contractile Actomyosin"
}
| null | null | null | null | true | null |
4673
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| null | null |
null |
{
"abstract": " We introduce a method for using Fizeau interferometry to measure the\nintrinsic resolving power of a diffraction grating. This method is more\naccurate than traditional techniques based on a long-trace profiler (LTP),\nsince it is sensitive to long-distance phase errors not revealed by a d-spacing\nmap. We demonstrate 50,400 resolving power for a mechanically ruled XUV grating\nfrom Inprentus, Inc.\n",
"title": "Intrinsic resolving power of XUV diffraction gratings measured with Fizeau interferometry"
}
| null | null | null | null | true | null |
4674
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| null | null |
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{
"abstract": " Determining the relative importance of environmental factors, biotic\ninteractions and stochasticity in assembling and maintaining species-rich\ncommunities remains a major challenge in ecology. In plant communities,\ninteractions between individuals of different species are expected to leave a\nspatial signature in the form of positive or negative spatial correlations over\ndistances relating to the spatial scale of interaction. Most studies using\nspatial point process tools have found relatively little evidence for\ninteractions between pairs of species. More interactions tend to be detected in\ncommunities with fewer species. However, there is currently no understanding of\nhow the power to detect spatial interactions may change with sample size, or\nthe scale and intensity of interactions.\nWe use a simple 2-species model where the scale and intensity of interactions\nare controlled to simulate point pattern data. In combination with an\napproximation to the variance of the spatial summary statistics that we sample,\nwe investigate the power of current spatial point pattern methods to correctly\nreject the null model of bivariate species independence.\nWe show that the power to detect interactions is positively related to the\nabundances of the species tested, and the intensity and scale of interactions.\nIncreasing imbalance in abundances has a negative effect on the power to detect\ninteractions. At population sizes typically found in currently available\ndatasets for species-rich plant communities we find only a very low power to\ndetect interactions. Differences in power may explain the increased frequency\nof interactions in communities with fewer species. Furthermore, the\ncommunity-wide frequency of detected interactions is very sensitive to a\nminimum abundance criterion for including species in the analyses.\n",
"title": "When do we have the power to detect biological interactions in spatial point patterns?"
}
| null | null | null | null | true | null |
4675
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| null | null |
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{
"abstract": " Classifiers and rating scores are prone to implicitly codifying biases, which\nmay be present in the training data, against protected classes (i.e., age,\ngender, or race). So it is important to understand how to design classifiers\nand scores that prevent discrimination in predictions. This paper develops\ncomputationally tractable algorithms for designing accurate but fair support\nvector machines (SVM's). Our approach imposes a constraint on the covariance\nmatrices conditioned on each protected class, which leads to a nonconvex\nquadratic constraint in the SVM formulation. We develop iterative algorithms to\ncompute fair linear and kernel SVM's, which solve a sequence of relaxations\nconstructed using a spectral decomposition of the nonconvex constraint. Its\neffectiveness in achieving high prediction accuracy while ensuring fairness is\nshown through numerical experiments on several data sets.\n",
"title": "Spectral Algorithms for Computing Fair Support Vector Machines"
}
| null | null | null | null | true | null |
4676
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| null | null |
null |
{
"abstract": " In this paper, we revisit the portfolio optimization problems of the\nminimization/maximization of investment risk under constraints of budget and\ninvestment concentration (primal problem) and the maximization/minimization of\ninvestment concentration under constraints of budget and investment risk (dual\nproblem) for the case that the variances of the return rates of the assets are\nidentical. We analyze both optimization problems by using the Lagrange\nmultiplier method and the random matrix approach. Thereafter, we compare the\nresults obtained from our proposed approach with the results obtained in\nprevious work. Moreover, we use numerical experiments to validate the results\nobtained from the replica approach and the random matrix approach as methods\nfor analyzing both the primal and dual portfolio optimization problems.\n",
"title": "Random matrix approach for primal-dual portfolio optimization problems"
}
| null | null | null | null | true | null |
4677
| null |
Default
| null | null |
null |
{
"abstract": " A method for constructing the Lax pairs for nonlinear integrable models is\nsuggested. First we look for a nonlinear invariant manifold to the\nlinearization of the given equation. Examples show that such invariant manifold\ndoes exist and can effectively be found. Actually it is defined by a quadratic\nform. As a result we get a nonlinear Lax pair consisting of the linearized\nequation and the invariant manifold. Our second step consists of finding an\nappropriate change of the variables to linearize the found nonlinear Lax pair.\nThe desired change of the variables is again defined by a quadratic form. The\nmethod is illustrated by the well-known KdV equation and the modified Volterra\nchain. New Lax pairs are found. The formal asymptotic expansions for their\neigenfunctions are constructed around the singular values of the spectral\nparameter. By applying the method of the formal diagonalization to these Lax\npairs the infinite series of the local conservation laws are obtained for the\ncorresponding nonlinear models.\n",
"title": "On a method for constructing the Lax pairs for integrable models via quadratic ansatz"
}
| null | null |
[
"Physics"
] | null | true | null |
4678
| null |
Validated
| null | null |
null |
{
"abstract": " Motivated by the need to detect an underground cavity within the procedure of\nan On-Site-Inspection (OSI), of the Comprehensive Nuclear Test Ban Treaty\nOrganization, the aim of this paper is to present results on the comparison of\nour numerical simulations with an analytic solution. The accurate numerical\nmodeling can facilitate the development of proper analysis techniques to detect\nthe remnants of an underground nuclear test. The larger goal is to help set a\nrigorous scientific base of OSI and to contribute to bringing the Treaty into\nforce. For our 3D numerical simulations, we use the discontinuous Galerkin\nSpectral Element Code SPEED jointly developed at MOX (The Laboratory for\nModeling and Scientific Computing, Department of Mathematics) and at DICA\n(Department of Civil and Environmental Engineering) of the Politecnico di\nMilano.\n",
"title": "Insight into the modeling of seismic waves for detection of underground cavities"
}
| null | null | null | null | true | null |
4679
| null |
Default
| null | null |
null |
{
"abstract": " The most distant AGN, within the allowed GZK cut-off radius, have been\nrecently candidate by many authors as the best location for observed UHECR\norigination. Indeed, the apparent homogeneity and isotropy of recent UHECR\nsignals seems to require a far cosmic isotropic and homogeneous scenario\ninvolving a proton UHECR courier: our galaxy or nearest local group or super\ngalactic plane (ruled by Virgo cluster) are too much near and apparently too\nmuch anisotropic in disagreement with PAO and TA almost homogeneous sample\ndata. However, the few and mild observed UHECR clustering, the North and South\nHot Spots, are smeared in wide solid angles. Their consequent random walk\nflight from most far GZK UHECR sources, nearly at 100 Mpc, must be delayed\n(with respect to a straight AGN photon gamma flaring arrival trajectory) at\nleast by a million years. During this time, the AGN jet blazing signal, its\nprobable axis deflection (such as the helical jet in Mrk501), its miss\nalignment or even its almost certain exhaust activity may lead to a complete\nmisleading correlation between present UHECR events and a much earlier active\nAGN ejection. UHECR maps maybe anyway related to galactic or nearest (Cen A,\nM82) AGN extragalactic UHECR sources shining in twin Hot Spot. Therefore we\ndefend our (quite different) scenarios where UHECR are mostly made by lightest\nUHECR nuclei originated by nearby AGN sources, or few galactic sources, whose\ndelayed signals reach us within few thousand years in the observed smeared sky\nareas.\n",
"title": "Uncorrelated far AGN flaring with their delayed UHECRs events"
}
| null | null |
[
"Physics"
] | null | true | null |
4680
| null |
Validated
| null | null |
null |
{
"abstract": " We show that quandle coverings in the sense of Eisermann form a (regular\nepi)-reflective subcategory of the category of surjective quandle\nhomomorphisms, both by using arguments coming from categorical Galois theory\nand by constructing concretely a centralization congruence. Moreover, we show\nthat a similar result holds for normal quandle extensions.\n",
"title": "How to centralize and normalize quandle extensions"
}
| null | null | null | null | true | null |
4681
| null |
Default
| null | null |
null |
{
"abstract": " We derive an extended fluctuation theorem for a geometric pumping in a\nspin-boson system under a periodic control of environmental temperatures by\nusing a Markovian quantum master equation. We perform the Monte-Carlo\nsimulation and obtain the current distribution, the average current and the\nfluctuation. Using the extended fluctuation theorem we try to explain the\nresults of our simulation. The fluctuation theorem leads to the fluctuation\ndissipation relations but the absence of the conventional reciprocal relation.\n",
"title": "Geometric Fluctuation Theorem"
}
| null | null | null | null | true | null |
4682
| null |
Default
| null | null |
null |
{
"abstract": " Ranking algorithms are the information gatekeepers of the Internet era. We\ndevelop a stylized model to study the effects of ranking algorithms on opinion\ndynamics. We consider a search engine that uses an algorithm based on\npopularity and on personalization. We find that popularity-based rankings\ngenerate an advantage of the fewer effect: fewer websites reporting a given\nsignal attract relatively more traffic overall. This highlights a novel,\nranking-driven channel that explains the diffusion of misinformation, as\nwebsites reporting incorrect information may attract an amplified amount of\ntraffic precisely because they are few. Furthermore, when individuals provide\nsufficiently positive feedback to the ranking algorithm, popularity-based\nrankings tend to aggregate information while personalization acts in the\nopposite direction.\n",
"title": "Opinion Dynamics via Search Engines (and other Algorithmic Gatekeepers)"
}
| null | null | null | null | true | null |
4683
| null |
Default
| null | null |
null |
{
"abstract": " In order for autonomous robots to be able to support people's well-being in\nhomes and everyday environments, new interactive capabilities will be required,\nas exemplified by the soft design used for Disney's recent robot character\nBaymax in popular fiction. Home robots will be required to be easy to interact\nwith and intelligent--adaptive, fun, unobtrusive and involving little effort to\npower and maintain--and capable of carrying out useful tasks both on an\neveryday level and during emergencies. The current article adopts an\nexploratory medium fidelity prototyping approach for testing some new robotic\ncapabilities in regard to recognizing people's activities and intentions and\nbehaving in a way which is transparent to people. Results are discussed with\nthe aim of informing next designs.\n",
"title": "Exploring home robot capabilities by medium fidelity prototyping"
}
| null | null | null | null | true | null |
4684
| null |
Default
| null | null |
null |
{
"abstract": " Unsupervised domain adaptation is the problem setting where data generating\ndistributions in the source and target domains are different, and labels in the\ntarget domain are unavailable. One important question in unsupervised domain\nadaptation is how to measure the difference between the source and target\ndomains. A previously proposed discrepancy that does not use the source domain\nlabels requires high computational cost to estimate and may lead to a loose\ngeneralization error bound in the target domain. To mitigate these problems, we\npropose a novel discrepancy called source-guided discrepancy (S-disc), which\nexploits labels in the source domain. As a consequence, S-disc can be computed\nefficiently with a finite sample convergence guarantee. In addition, we show\nthat S-disc can provide a tighter generalization error bound than the one based\non an existing discrepancy. Finally, we report experimental results that\ndemonstrate the advantages of S-disc over the existing discrepancies.\n",
"title": "Unsupervised Domain Adaptation Based on Source-guided Discrepancy"
}
| null | null | null | null | true | null |
4685
| null |
Default
| null | null |
null |
{
"abstract": " Given a distribution of defects on a structured surface, such as those\nrepresented by 2-dimensional crystalline materials, liquid crystalline\nsurfaces, and thin sandwiched shells, what is the resulting stress field and\nthe deformed shape? Motivated by this concern, we first classify, and quantify,\nthe translational, rotational, and metrical defects allowable over a broad\nclass of structured surfaces. With an appropriate notion of strain, the defect\ndensities are then shown to appear as sources of strain incompatibility. The\nstrain incompatibility relations, with appropriate kinematical assumptions on\nthe decomposition of strain into elastic and plastic parts, and the stress\nequilibrium relations, with a suitable choice of material response, provide the\nnecessary equations for determining both the internal stress field and the\ndeformed shape. We demonstrate this by applying our theory to Kirchhoff-Love\nshells with a kinematics which allows for small in-surface strains but\nmoderately large rotations.\n",
"title": "On structured surfaces with defects: geometry, strain incompatibility, internal stress, and natural shapes"
}
| null | null | null | null | true | null |
4686
| null |
Default
| null | null |
null |
{
"abstract": " A new management system for the SND detector experiments (at VEPP-2000\ncollider in Novosibirsk) is developed. We describe here the interaction between\na user and the SND databases. These databases contain experiment configuration,\nconditions and metadata. The new system is designed in client-server\narchitecture. It has several logical layers corresponding to the users roles. A\nnew template engine is created. A web application is implemented using Node.js\nframework. At the time the application provides: showing and editing\nconfiguration; showing experiment metadata and experiment conditions data\nindex; showing SND log (prototype).\n",
"title": "Management system for the SND experiments"
}
| null | null | null | null | true | null |
4687
| null |
Default
| null | null |
null |
{
"abstract": " Spiking neural networks (SNNs) could play a key role in unsupervised machine\nlearning applications, by virtue of strengths related to learning from the fine\ntemporal structure of event-based signals. However, some spike-timing-related\nstrengths of SNNs are hindered by the sensitivity of spike-timing-dependent\nplasticity (STDP) rules to input spike rates, as fine temporal correlations may\nbe obstructed by coarser correlations between firing rates. In this article, we\npropose a spike-timing-dependent learning rule that allows a neuron to learn\nfrom the temporally-coded information despite the presence of rate codes. Our\nlong-term plasticity rule makes use of short-term synaptic fatigue dynamics. We\nshow analytically that, in contrast to conventional STDP rules, our fatiguing\nSTDP (FSTDP) helps learn the temporal code, and we derive the necessary\nconditions to optimize the learning process. We showcase the effectiveness of\nFSTDP in learning spike-timing correlations among processes of different rates\nin synthetic data. Finally, we use FSTDP to detect correlations in real-world\nweather data from the United States in an experimental realization of the\nalgorithm that uses a neuromorphic hardware platform comprising phase-change\nmemristive devices. Taken together, our analyses and demonstrations suggest\nthat FSTDP paves the way for the exploitation of the spike-based strengths of\nSNNs in real-world applications.\n",
"title": "Fatiguing STDP: Learning from Spike-Timing Codes in the Presence of Rate Codes"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
4688
| null |
Validated
| null | null |
null |
{
"abstract": " Distribution grids are currently challenged by frequent voltage excursions\ninduced by intermittent solar generation. Smart inverters have been advocated\nas a fast-responding means to regulate voltage and minimize ohmic losses. Since\noptimal inverter coordination may be computationally challenging and preset\nlocal control rules are subpar, the approach of customized control rules\ndesigned in a quasi-static fashion features as a golden middle. Departing from\naffine control rules, this work puts forth non-linear inverter control\npolicies. Drawing analogies to multi-task learning, reactive control is posed\nas a kernel-based regression task. Leveraging a linearized grid model and given\nanticipated data scenarios, inverter rules are jointly designed at the feeder\nlevel to minimize a convex combination of voltage deviations and ohmic losses\nvia a linearly-constrained quadratic program. Numerical tests using real-world\ndata on a benchmark feeder demonstrate that nonlinear control rules driven also\nby a few non-local readings can attain near-optimal performance.\n",
"title": "Kernel-Based Learning for Smart Inverter Control"
}
| null | null | null | null | true | null |
4689
| null |
Default
| null | null |
null |
{
"abstract": " There is an ongoing debate in the literature about whether the present global\nwarming is increasing local and global temperature variability. The central\nmethodological issues of this debate relate to the proper treatment of\nnormalised temperature anomalies and trends in the studied time series which\nmay be difficult to separate from time-evolving fluctuations. Some argue that\ntemperature variability is indeed increasing globally, whereas others conclude\nit is decreasing or remains practically unchanged. Meanwhile, a consensus\nappears to emerge that local variability in certain regions (e.g. Western\nEurope and North America) has indeed been increasing in the past 40 years. Here\nwe investigate the nature of connections between external forcing and climate\nvariability conceptually by using a laboratory-scale minimal model of\nmid-latitude atmospheric thermal convection subject to continuously decreasing\n`equator-to-pole' temperature contrast, mimicking climate change. The analysis\nof temperature records from an ensemble of experimental runs (`realisations')\nall driven by identical time-dependent external forcing reveals that the\ncollective variability of the ensemble and that of individual realisations may\nbe markedly different -- a property to be considered when interpreting climate\nrecords.\n",
"title": "Temperature fluctuations in a changing climate: an ensemble-based experimental approach"
}
| null | null | null | null | true | null |
4690
| null |
Default
| null | null |
null |
{
"abstract": " We introduce twisted matrix factorizations for quantum complete intersections\nof codimension two. For such an algebra, we show that in a given dimension,\nalmost all the indecomposable modules with bounded minimal projective\nresolutions correspond to such matrix factorizations.\n",
"title": "Matrix factorizations for quantum complete intersections"
}
| null | null | null | null | true | null |
4691
| null |
Default
| null | null |
null |
{
"abstract": " We provide a deterministic data summarization algorithm that approximates the\nmean $\\bar{p}=\\frac{1}{n}\\sum_{p\\in P} p$ of a set $P$ of $n$ vectors in\n$\\REAL^d$, by a weighted mean $\\tilde{p}$ of a \\emph{subset} of $O(1/\\eps)$\nvectors, i.e., independent of both $n$ and $d$. We prove that the squared\nEuclidean distance between $\\bar{p}$ and $\\tilde{p}$ is at most $\\eps$\nmultiplied by the variance of $P$. We use this algorithm to maintain an\napproximated sum of vectors from an unbounded stream, using memory that is\nindependent of $d$, and logarithmic in the $n$ vectors seen so far. Our main\napplication is to extract and represent in a compact way friend groups and\nactivity summaries of users from underlying data exchanges. For example, in the\ncase of mobile networks, we can use GPS traces to identify meetings, in the\ncase of social networks, we can use information exchange to identify friend\ngroups. Our algorithm provably identifies the {\\it Heavy Hitter} entries in a\nproximity (adjacency) matrix. The Heavy Hitters can be used to extract and\nrepresent in a compact way friend groups and activity summaries of users from\nunderlying data exchanges. We evaluate the algorithm on several large data\nsets.\n",
"title": "Coresets for Vector Summarization with Applications to Network Graphs"
}
| null | null | null | null | true | null |
4692
| null |
Default
| null | null |
null |
{
"abstract": " The nonlinear lattice---a new and nonlinear class of periodic\npotentials---was recently introduced to generate various nonlinear localized\nmodes. Several attempts failed to stabilize two-dimensional (2D) solitons\nagainst their intrinsic critical collapse in Kerr media. Here, we provide a\npossibility for supporting 2D matter-wave solitons and vortices in an extended\nsetting---the cubic and quintic model---by introducing another nonlinear\nlattice whose period is controllable and can be different from its cubic\ncounterpart, to its quintic nonlinearity, therefore making a fully `nonlinear\nquasi-crystal'.\nA variational approximation based on Gaussian ansatz is developed for the\nfundamental solitons and in particular, their stability exactly follows the\ninverted \\textit{Vakhitov-Kolokolov} stability criterion, whereas the vortex\nsolitons are only studied by means of numerical methods. Stability regions for\ntwo types of localized mode---the fundamental and vortex solitons---are\nprovided. A noteworthy feature of the localized solutions is that the vortex\nsolitons are stable only when the period of the quintic nonlinear lattice is\nthe same as the cubic one or when the quintic nonlinearity is constant, while\nthe stable fundamental solitons can be created under looser conditions. Our\nphysical setting (cubic-quintic model) is in the framework of the\nGross-Pitaevskii equation (GPE) or nonlinear Schrödinger equation, the\npredicted localized modes thus may be implemented in Bose-Einstein condensates\nand nonlinear optical media with tunable cubic and quintic nonlinearities.\n",
"title": "Two-dimensional matter-wave solitons and vortices in competing cubic-quintic nonlinear lattices"
}
| null | null | null | null | true | null |
4693
| null |
Default
| null | null |
null |
{
"abstract": " Improvements of entity-relationship (E-R) search techniques have been\nhampered by a lack of test collections, particularly for complex queries\ninvolving multiple entities and relationships. In this paper we describe a\nmethod for generating E-R test queries to support comprehensive E-R search\nexperiments. Queries and relevance judgments are created from content that\nexists in a tabular form where columns represent entity types and the table\nstructure implies one or more relationships among the entities. Editorial work\ninvolves creating natural language queries based on relationships represented\nby the entries in the table. We have publicly released the RELink test\ncollection comprising 600 queries and relevance judgments obtained from a\nsample of Wikipedia List-of-lists-of-lists tables. The latter comprise tuples\nof entities that are extracted from columns and labelled by corresponding\nentity types and relationships they represent. In order to facilitate research\nin complex E-R retrieval, we have created and released as open source the\nRELink Framework that includes Apache Lucene indexing and search specifically\ntailored to E-R retrieval. RELink includes entity and relationship indexing\nbased on the ClueWeb-09-B Web collection with FACC1 text span annotations\nlinked to Wikipedia entities. With ready to use search resources and a\ncomprehensive test collection, we support community in pursuing E-R research at\nscale.\n",
"title": "RELink: A Research Framework and Test Collection for Entity-Relationship Retrieval"
}
| null | null | null | null | true | null |
4694
| null |
Default
| null | null |
null |
{
"abstract": " Humanoid robotics research depends on capable robot platforms, but recently\ndeveloped advanced platforms are often not available to other research groups,\nexpensive, dangerous to operate, or closed-source. The lack of available\nplatforms forces researchers to work with smaller robots, which have less\nstrict dynamic constraints or with simulations, which lack many real-world\neffects. We developed NimbRo-OP2X to address this need. At a height of 135 cm\nour robot is large enough to interact in a human environment. Its low weight of\nonly 19 kg makes the operation of the robot safe and easy, as no special\noperational equipment is necessary. Our robot is equipped with a fast onboard\ncomputer and a GPU to accelerate parallel computations. We extend our already\nopen-source software by a deep-learning based vision system and gait parameter\noptimisation. The NimbRo-OP2X was evaluated during RoboCup 2018 in Montréal,\nCanada, where it won all possible awards in the Humanoid AdultSize class.\n",
"title": "NimbRo-OP2X: Adult-sized Open-source 3D Printed Humanoid Robot"
}
| null | null | null | null | true | null |
4695
| null |
Default
| null | null |
null |
{
"abstract": " Silicon nitride is awell-established material for photonic devices and\nintegrated circuits. It displays a broad transparency window spanning from the\nvisible to the mid-IR and waveguides can be manufactured with low losses. An\nabsence of nonlinear multi-photon absorption in the erbium lightwave\ncommunications band has enabled various nonlinear optic applications in the\npast decade. Silicon nitride is a dielectric material whose optical and\nmechanical properties strongly depend on the deposition conditions. In\nparticular, the optical bandgap can be modified with the gas flow ratio during\nlow-pressure chemical vapor deposition (LPCVD). Here we show that this\nparameter can be controlled in a highly reproducible manner, providing an\napproach to synthesize the nonlinear Kerr coefficient of the material. This\nholistic empirical study provides relevant guidelines to optimize the\nproperties of LPCVD silicon nitride waveguides for nonlinear optics\napplications that rely on the Kerr effect.\n",
"title": "Optical bandgap engineering in nonlinear silicon nitride waveguides"
}
| null | null |
[
"Physics"
] | null | true | null |
4696
| null |
Validated
| null | null |
null |
{
"abstract": " We propose a new selection rule for the coordinate selection in coordinate\ndescent methods for huge-scale optimization. The efficiency of this novel\nscheme is provably better than the efficiency of uniformly random selection,\nand can reach the efficiency of steepest coordinate descent (SCD), enabling an\nacceleration of a factor of up to $n$, the number of coordinates. In many\npractical applications, our scheme can be implemented at no extra cost and\ncomputational efficiency very close to the faster uniform selection. Numerical\nexperiments with Lasso and Ridge regression show promising improvements, in\nline with our theoretical guarantees.\n",
"title": "Approximate Steepest Coordinate Descent"
}
| null | null | null | null | true | null |
4697
| null |
Default
| null | null |
null |
{
"abstract": " Convolutional and Recurrent, deep neural networks have been successful in\nmachine learning systems for computer vision, reinforcement learning, and other\nallied fields. However, the robustness of such neural networks is seldom\napprised, especially after high classification accuracy has been attained. In\nthis paper, we evaluate the robustness of three recurrent neural networks to\ntiny perturbations, on three widely used datasets, to argue that high accuracy\ndoes not always mean a stable and a robust (to bounded perturbations,\nadversarial attacks, etc.) system. Especially, normalizing the spectrum of the\ndiscrete recurrent network to bound the spectrum (using power method, Rayleigh\nquotient, etc.) on a unit disk produces stable, albeit highly non-robust neural\nnetworks. Furthermore, using the $\\epsilon$-pseudo-spectrum, we show that\ntraining of recurrent networks, say using gradient-based methods, often result\nin non-normal matrices that may or may not be diagonalizable. Therefore, the\nopen problem lies in constructing methods that optimize not only for accuracy\nbut also for the stability and the robustness of the underlying neural network,\na criterion that is distinct from the other.\n",
"title": "How Robust are Deep Neural Networks?"
}
| null | null | null | null | true | null |
4698
| null |
Default
| null | null |
null |
{
"abstract": " An ability to model a generative process and learn a latent representation\nfor speech in an unsupervised fashion will be crucial to process vast\nquantities of unlabelled speech data. Recently, deep probabilistic generative\nmodels such as Variational Autoencoders (VAEs) have achieved tremendous success\nin modeling natural images. In this paper, we apply a convolutional VAE to\nmodel the generative process of natural speech. We derive latent space\narithmetic operations to disentangle learned latent representations. We\ndemonstrate the capability of our model to modify the phonetic content or the\nspeaker identity for speech segments using the derived operations, without the\nneed for parallel supervisory data.\n",
"title": "Learning Latent Representations for Speech Generation and Transformation"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
4699
| null |
Validated
| null | null |
null |
{
"abstract": " We propose an efficient algorithm for approximate computation of the profile\nmaximum likelihood (PML), a variant of maximum likelihood maximizing the\nprobability of observing a sufficient statistic rather than the empirical\nsample. The PML has appealing theoretical properties, but is difficult to\ncompute exactly. Inspired by observations gleaned from exactly solvable cases,\nwe look for an approximate PML solution, which, intuitively, clumps comparably\nfrequent symbols into one symbol. This amounts to lower-bounding a certain\nmatrix permanent by summing over a subgroup of the symmetric group rather than\nthe whole group during the computation. We extensively experiment with the\napproximate solution, and find the empirical performance of our approach is\ncompetitive and sometimes significantly better than state-of-the-art\nperformance for various estimation problems.\n",
"title": "Approximate Profile Maximum Likelihood"
}
| null | null | null | null | true | null |
4700
| null |
Default
| null | null |
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