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dict | prediction
null | prediction_agent
null | annotation
list | annotation_agent
null | multi_label
bool 1
class | explanation
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{
"abstract": " We report on the ab initio discovery of a novel putative ground state for\nquasi two-dimensional TiO$_2$ through a structural search using the minima\nhopping method with an artificial neural network potential. The structure is\nbased on a honeycomb lattice and is energetically lower than the experimentally\nreported lepidocrocite sheet by 7~meV/atom, and merely 13~meV/atom higher in\nenergy than the ground state rutile bulk structure. According to our\ncalculations, the hexagonal sheet is stable against mechanical stress, it is\nchemically inert and can be deposited on various substrates without disrupting\nthe structure. Its properties differ significantly from all known TiO$_2$ bulk\nphases with a large gap of 5.05~eV that can be tuned through strain\nengineering.\n",
"title": "A two-dimensional hexagonal sheet of TiO$_2$"
}
| null | null | null | null | true | null |
9001
| null |
Default
| null | null |
null |
{
"abstract": " From basic considerations of the Lie group that preserves a target\nprobability measure, we derive the Barker, Metropolis, and ensemble Markov\nchain Monte Carlo (MCMC) algorithms, as well as two new MCMC algorithms. The\nconvergence properties of these new algorithms successively improve on the\nstate of the art. We illustrate the new algorithms with explicit numerical\ncomputations, and we empirically demonstrate the improved convergence on a spin\nglass.\n",
"title": "Fast Markov Chain Monte Carlo Algorithms via Lie Groups"
}
| null | null | null | null | true | null |
9002
| null |
Default
| null | null |
null |
{
"abstract": " An $(r, \\ell)$-partition of a graph $G$ is a partition of its vertex set into\n$r$ independent sets and $\\ell$ cliques. A graph is $(r, \\ell)$ if it admits an\n$(r, \\ell)$-partition. A graph is well-covered if every maximal independent set\nis also maximum. A graph is $(r,\\ell)$-well-covered if it is both $(r,\\ell)$\nand well-covered. In this paper we consider two different decision problems. In\nthe $(r,\\ell)$-Well-Covered Graph problem ($(r,\\ell)$WCG for short), we are\ngiven a graph $G$, and the question is whether $G$ is an\n$(r,\\ell)$-well-covered graph. In the Well-Covered $(r,\\ell)$-Graph problem\n(WC$(r,\\ell)$G for short), we are given an $(r,\\ell)$-graph $G$ together with\nan $(r,\\ell)$-partition of $V(G)$ into $r$ independent sets and $\\ell$ cliques,\nand the question is whether $G$ is well-covered. We classify most of these\nproblems into P, coNP-complete, NP-complete, NP-hard, or coNP-hard. Only the\ncases WC$(r,0)$G for $r\\geq 3$ remain open. In addition, we consider the\nparameterized complexity of these problems for several choices of parameters,\nsuch as the size $\\alpha$ of a maximum independent set of the input graph, its\nneighborhood diversity, its clique-width, or the number $\\ell$ of cliques in an\n$(r, \\ell)$-partition. In particular, we show that the parameterized problem of\ndeciding whether a general graph is well-covered parameterized by $\\alpha$ can\nbe reduced to the WC$(0,\\ell)$G problem parameterized by $\\ell$. In addition,\nwe prove that both problems are coW[2]-hard but can be solved in XP-time.\n",
"title": "On the (parameterized) complexity of recognizing well-covered (r,l)-graphs"
}
| null | null |
[
"Computer Science"
] | null | true | null |
9003
| null |
Validated
| null | null |
null |
{
"abstract": " In a series of papers, Bartelt and co-workers developed novel snow-avalanche\nmodels in which \\emph{random kinetic energy} $R_K$ (a.k.a.\\ granular\ntemperature) is a key concept. The earliest models were for a single, constant\ndensity layer, using a Voellmy model but with $R_K$-dependent friction\nparameters. This was then extended to variable density, and finally a\nsuspension layer (powder-snow cloud) was added. The physical basis and\nmathematical formulation of these models is critically reviewed here, with the\nfollowing main findings: (i) Key assumptions in the original RKE model differ\nsubstantially from established results on dense granular flows; in particular,\nthe effective friction coefficient decreases to zero with velocity in the RKE\nmodel. (ii) In the variable-density model, non-canonical interpretation of the\nenergy balance leads to a third-order evolution equation for the flow depth or\ndensity, whereas the stated assumptions imply a first-order equation. (iii) The\nmodel for the suspension layer neglects gravity and disregards well established\ntheoretical and experimental results on particulate gravity currents. Some\noptions for improving these aspects are discussed.\n",
"title": "Comments on avalanche flow models based on the concept of random kinetic energy"
}
| null | null | null | null | true | null |
9004
| null |
Default
| null | null |
null |
{
"abstract": " As mobile devices have become indispensable in modern life, mobile security\nis becoming much more important. Traditional password or PIN-like\npoint-of-entry security measures score low on usability and are vulnerable to\nbrute force and other types of attacks. In order to improve mobile security, an\nadaptive neuro-fuzzy inference system(ANFIS)-based implicit authentication\nsystem is proposed in this paper to provide authentication in a continuous and\ntransparent manner.To illustrate the applicability and capability of ANFIS in\nour implicit authentication system, experiments were conducted on behavioural\ndata collected for up to 12 weeks from different Android users. The ability of\nthe ANFIS-based system to detect an adversary is also tested with scenarios\ninvolving an attacker with varying levels of knowledge. The results demonstrate\nthat ANFIS is a feasible and efficient approach for implicit authentication\nwith an average of 95% user recognition rate. Moreover, the use of ANFIS-based\nsystem for implicit authentication significantly reduces manual tuning and\nconfiguration tasks due to its selflearning capability.\n",
"title": "Continuous Implicit Authentication for Mobile Devices based on Adaptive Neuro-Fuzzy Inference System"
}
| null | null | null | null | true | null |
9005
| null |
Default
| null | null |
null |
{
"abstract": " The mass-imbalanced three-body recombination process that forms a shallow\ndimer is shown to possess a rich Efimov-Stückelberg landscape, with\ncorresponding spectra that differ fundamentally from the homonuclear case. A\nsemi-analytical treatment of the three-body recombination predicts an unusual\nspectra with intertwined resonance peaks and minima, and yields in-depth\ninsight into the behavior of the corresponding Efimov spectra. In particular,\nthe patterns of the Efimov-Stückelberg landscape are shown to depend\ninherently on the degree of diabaticity of the three-body collisions, which\nstrongly affects the universality of the heteronuclear Efimov states.\n",
"title": "Ultracold heteronuclear three-body systems: How diabaticity limits the universality of recombination into shallow dimers"
}
| null | null |
[
"Physics"
] | null | true | null |
9006
| null |
Validated
| null | null |
null |
{
"abstract": " Partially observable Markov decision processes (POMDPs) are a powerful\nabstraction for tasks that require decision making under uncertainty, and\ncapture a wide range of real world tasks. Today, effective planning approaches\nexist that generate effective strategies given black-box models of a POMDP\ntask. Yet, an open question is how to acquire accurate models for complex\ndomains. In this paper we propose DELIP, an approach to model learning for\nPOMDPs that utilizes amortized structured variational inference. We empirically\nshow that our model leads to effective control strategies when coupled with\nstate-of-the-art planners. Intuitively, model-based approaches should be\nparticularly beneficial in environments with changing reward structures, or\nwhere rewards are initially unknown. Our experiments confirm that DELIP is\nparticularly effective in this setting.\n",
"title": "Variational Inference for Data-Efficient Model Learning in POMDPs"
}
| null | null | null | null | true | null |
9007
| null |
Default
| null | null |
null |
{
"abstract": " The ANAIS experiment aims at the confirmation of the DAMA/LIBRA signal at the\nCanfranc Underground Laboratory (LSC). Several 12.5 kg NaI(Tl) modules produced\nby Alpha Spectra Inc. have been operated there during the last years in various\nset-ups; an outstanding light collection at the level of 15 photoelectrons per\nkeV, which allows triggering at 1 keV of visible energy, has been measured for\nall of them and a complete characterization of their background has been\nachieved. In the first months of 2017, the full ANAIS-112 set-up consisting of\nnine Alpha Spectra detectors with a total mass of 112.5 kg was commissioned at\nLSC and the first dark matter run started in August, 2017. Here, the latest\nresults on the detectors performance and measured background from the\ncommissioning run will be presented and the sensitivity prospects of the\nANAIS-112 experiment will be discussed.\n",
"title": "The ANAIS-112 experiment at the Canfranc Underground Laboratory"
}
| null | null | null | null | true | null |
9008
| null |
Default
| null | null |
null |
{
"abstract": " The logarithmic strain measures $\\lVert\\log U\\rVert^2$, where $\\log U$ is the\nprincipal matrix logarithm of the stretch tensor $U=\\sqrt{F^TF}$ corresponding\nto the deformation gradient $F$ and $\\lVert\\,.\\,\\rVert$ denotes the Frobenius\nmatrix norm, arises naturally via the geodesic distance of $F$ to the special\northogonal group $\\operatorname{SO}(n)$. This purely geometric characterization\nof this strain measure suggests that a viable constitutive law of nonlinear\nelasticity may be derived from an elastic energy potential which depends solely\non this intrinsic property of the deformation, i.e. that an energy function\n$W\\colon\\operatorname{GL^+}(n)\\to\\mathbb{R}$ of the form \\begin{equation}\nW(F)=\\Psi(\\lVert\\log U\\rVert^2) \\tag{1} \\end{equation} with a suitable\nfunction $\\Psi\\colon[0,\\infty)\\to\\mathbb{R}$ should be used to describe finite\nelastic deformations.\nHowever, while such energy functions enjoy a number of favorable properties,\nwe show that it is not possible to find a strictly monotone function $\\Psi$\nsuch that $W$ of the form (1) is Legendre-Hadamard elliptic.\nSimilarly, we consider the related isochoric strain measure\n$\\lVert\\operatorname{dev}_n\\log U\\rVert^2$, where $\\operatorname{dev}_n \\log U$\nis the deviatoric part of $\\log U$. Although a polyconvex energy function in\nterms of this strain measure has recently been constructed in the planar case\n$n=2$, we show that for $n\\geq3$, no strictly monotone function\n$\\Psi\\colon[0,\\infty)\\to\\mathbb{R}$ exists such that $F\\mapsto\n\\Psi(\\lVert\\operatorname{dev}_n\\log U\\rVert^2)$ is polyconvex or even rank-one\nconvex. Moreover, a volumetric-isochorically decoupled energy of the form\n$F\\mapsto \\Psi(\\lVert\\operatorname{dev}_n\\log U\\rVert^2) +\nW_{\\mathrm{vol}}(\\det F)$ cannot be rank-one convex for any function\n$W_{\\mathrm{vol}}\\colon(0,\\infty)\\to\\mathbb{R}$ if $\\Psi$ is strictly monotone.\n",
"title": "A non-ellipticity result, or the impossible taming of the logarithmic strain measure"
}
| null | null | null | null | true | null |
9009
| null |
Default
| null | null |
null |
{
"abstract": " We present an interpretable neural network for predicting an important\nclinical outcome (1-year mortality) from multi-modal Electronic Health Record\n(EHR) data. Our approach builds on prior multi-modal machine learning models by\nnow enabling visualization of how individual factors contribute to the overall\noutcome risk, assuming other factors remain constant, which was previously\nimpossible.\nWe demonstrate the value of this approach using a large multi-modal clinical\ndataset including both EHR data and 31,278 echocardiographic videos of the\nheart from 26,793 patients. We generated separate models for (i) clinical data\nonly (CD) (e.g. age, sex, diagnoses and laboratory values), (ii) numeric\nvariables derived from the videos, which we call echocardiography-derived\nmeasures (EDM), and (iii) CD+EDM+raw videos (pixel data). The interpretable\nmulti-modal model maintained performance compared to non-interpretable models\n(Random Forest, XGBoost), and also performed significantly better than a model\nusing a single modality (average AUC=0.82). Clinically relevant insights and\nmulti-modal variable importance rankings were also facilitated by the new\nmodel, which have previously been impossible.\n",
"title": "Interpretable Neural Networks for Predicting Mortality Risk using Multi-modal Electronic Health Records"
}
| null | null | null | null | true | null |
9010
| null |
Default
| null | null |
null |
{
"abstract": " This paper presents a new way to design a Fuzzy Terminal Iterative Learning\nControl (TILC) to control the heater temperature setpoints of a thermoforming\nmachine. This fuzzy TILC is based on the inverse of a fuzzy model of this\nmachine, and is built from experimental (or simulation) data with kriging\ninterpolation. The Fuzzy Inference System usually used for a fuzzy model is the\nzero order Takagi Sugeno Kwan system (constant consequents). In this paper, the\n1st order Takagi Sugeno Kwan system is used, with the fuzzy model rules\nexpressed using matrices. This makes the inversion of the fuzzy model much\neasier than the inversion of the fuzzy model based on the TSK of order 0. Based\non simulation results, the proposed fuzzy TILC seems able to give a very good\ninitial guess as to the heater temperature setpoints, making it possible to\nhave almost no wastage of plastic sheets. Simulation results show the\neffectiveness of the fuzzy TILC compared to a crisp TILC, even though the fuzzy\ncontroller is based on a fuzzy model built from noisy data.\n",
"title": "Automatic Temperature Setpoint Tuning of a Thermoforming Machine using Fuzzy Terminal Iterative Learning Control"
}
| null | null | null | null | true | null |
9011
| null |
Default
| null | null |
null |
{
"abstract": " Our purpose in this present paper is to investigate generalized integration\nformulas containing the extended generalized hypergeometric function and\nobtained results are expressed in terms of extended hypergeometric function.\nCertain special cases of the main results presented here are also pointed out\nfor the extended Gauss' hypergeometric and confluent hypergeometric functions.\n",
"title": "A New Class of Integrals Involving Extended Hypergeometric Function"
}
| null | null | null | null | true | null |
9012
| null |
Default
| null | null |
null |
{
"abstract": " In two recent publications ( Int. J. Quant. Chem. 114, 1645 (2014) and Molec.\nPhys. 114, 227 (2016)) it was shown that the Born -Hwang (BH) treatment of a\nmolecular system perturbed by an external field yields a set of decoupled\nvectorial Wave Equations, just like in Electromagnetism. This finding led us to\ndeclare on the existence of a new type of Fields, which were termed Molecular\nFields. The fact that such fields exist implies that at the vicinity of conical\nintersections exist a mechanism that transforms a passing-by electric beam into\na field which differs from the original electric field. This situation is\nreminiscent of what is encountered in astronomy where Black Holes formed by\nmassive stars may affect the nature of a near-by beam of light. Thus if the\nNonAdiabatic-Coupling-Terms (NACT) with their singular points may affect the\nnature of such a beam (see the above two publications) then it would be\ninteresting to know to what extend NACTs (and consequently also the BH\nequation) will be affected by the special theory of relativity as introduced by\nDirac. Indeed while applying the Dirac approach we derived the relativistic\naffected NACTs as well as the corresponding BH equation.\n",
"title": "The Special Theory of Relativity as Applied to the Born-Oppenheimer-Huang Approach"
}
| null | null | null | null | true | null |
9013
| null |
Default
| null | null |
null |
{
"abstract": " Understanding structural controllability of a complex network requires to\nidentify a Minimum Input nodes Set (MIS) of the network. It has been suggested\nthat finding an MIS is equivalent to computing a maximum matching of the\nnetwork, where the unmatched nodes constitute an MIS. However, maximum matching\nof a network is often not unique, and finding all MISs may provide deep\ninsights to the controllability of the network. Finding all possible input\nnodes, which form the union of all MISs, is computationally challenging for\nlarge networks. Here we present an efficient enumerative algorithm for the\nproblem. The main idea is to modify a maximum matching algorithm to make it\nefficient for finding all possible input nodes by computing only one MIS. We\nrigorously proved the correctness of the new algorithm and evaluated its\nperformance on synthetic and large real networks. The experimental results\nshowed that the new algorithm ran several orders of magnitude faster than the\nexisting method on large real networks.\n",
"title": "An efficient algorithm for finding all possible input nodes for controlling complex networks"
}
| null | null |
[
"Computer Science",
"Physics"
] | null | true | null |
9014
| null |
Validated
| null | null |
null |
{
"abstract": " Heat can generally transfer via thermal conduction, thermal radiation, and\nthermal convection. All the existing theories of transformation thermotics and\noptics can treat thermal conduction and thermal radiation, respectively.\nUnfortunately, thermal convection has never been touched in transformation\ntheories due to the lack of a suitable theory, thus limiting applications\nassociated with heat transfer through fluids (liquid or gas). Here, we develop,\nfor the first time, a general theory of transformation thermal convection by\nconsidering the convection-diffusion equation, the Navier-Stokes equation, and\nthe Darcy law. By introducing porous media, we get a set of coupled equations\nkeeping their forms under coordinate transformation. As model applications, the\ntheory helps to show the effects of cloaking, concentrating, and camouflage.\nOur finite element simulations confirm the theoretical findings. This work\noffers a general transformation theory for thermal convection, thus revealing\nsome novel behaviors of thermal convection; it not only provides new hints on\nhow to control heat transfer by combining thermal conduction, thermal\nradiation, and thermal convection, but also benefits the study of mass\ndiffusion and other related fields that contain a set of equations and need to\ntransform velocities at the same time.\n",
"title": "Transformation thermal convection: Cloaking, concentrating, and camouflage"
}
| null | null | null | null | true | null |
9015
| null |
Default
| null | null |
null |
{
"abstract": " We report a highly efficient tunable THz reflector in graphene. By applying a\nsmall gate voltage (up to 3 V), the reflectance of graphene is modulated from a\nminimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures\nat room temperature, and the reflection tuning is uniform within a wide\nspectral range (0.1 - 1.5 THz). Our observation is explained by the Drude\nmodel, which describes the THz wave-induced intraband transition in graphene.\nThis tunable reflectance of graphene may contribute to broadband THz mirrors,\ndeformable THz mirrors, variable THz beam splitters and other optical\ncomponents.\n",
"title": "Tunable terahertz reflection of graphene via ionic liquid gating"
}
| null | null | null | null | true | null |
9016
| null |
Default
| null | null |
null |
{
"abstract": " Kernel online convex optimization (KOCO) is a framework combining the\nexpressiveness of non-parametric kernel models with the regret guarantees of\nonline learning. First-order KOCO methods such as functional gradient descent\nrequire only $\\mathcal{O}(t)$ time and space per iteration, and, when the only\ninformation on the losses is their convexity, achieve a minimax optimal\n$\\mathcal{O}(\\sqrt{T})$ regret. Nonetheless, many common losses in kernel\nproblems, such as squared loss, logistic loss, and squared hinge loss posses\nstronger curvature that can be exploited. In this case, second-order KOCO\nmethods achieve $\\mathcal{O}(\\log(\\text{Det}(\\boldsymbol{K})))$ regret, which\nwe show scales as $\\mathcal{O}(d_{\\text{eff}}\\log T)$, where $d_{\\text{eff}}$\nis the effective dimension of the problem and is usually much smaller than\n$\\mathcal{O}(\\sqrt{T})$. The main drawback of second-order methods is their\nmuch higher $\\mathcal{O}(t^2)$ space and time complexity. In this paper, we\nintroduce kernel online Newton step (KONS), a new second-order KOCO method that\nalso achieves $\\mathcal{O}(d_{\\text{eff}}\\log T)$ regret. To address the\ncomputational complexity of second-order methods, we introduce a new matrix\nsketching algorithm for the kernel matrix $\\boldsymbol{K}_t$, and show that for\na chosen parameter $\\gamma \\leq 1$ our Sketched-KONS reduces the space and time\ncomplexity by a factor of $\\gamma^2$ to $\\mathcal{O}(t^2\\gamma^2)$ space and\ntime per iteration, while incurring only $1/\\gamma$ times more regret.\n",
"title": "Second-Order Kernel Online Convex Optimization with Adaptive Sketching"
}
| null | null | null | null | true | null |
9017
| null |
Default
| null | null |
null |
{
"abstract": " For an endofunctor $H$ on a hyper-extensive category preserving countable\ncoproducts we describe the free corecursive algebra on $Y$ as the coproduct of\nthe final coalgebra for $H$ and the free $H$-algebra on $Y$. As a consequence,\nwe derive that $H$ is a cia functor, i.e., its corecursive algebras are\nprecisely the cias (completely iterative algebras). Also all functors $H(-) +\nY$ are then cia functors. For finitary set functors we prove that, conversely,\nif $H$ is a cia functor, then it has the form $H = W \\times (-) + Y$ for some\nsets $W$ and $Y$.\n",
"title": "On Corecursive Algebras for Functors Preserving Coproducts"
}
| null | null | null | null | true | null |
9018
| null |
Default
| null | null |
null |
{
"abstract": " The article is about the representation theory of an inner form~$G$ of a\ngeneral linear group over a non-archimedean local field. We introduce\nsemisimple characters for~$G$ whose intertwining classes describe conjecturally\nvia Local Langlands correspondence the behavior on wild inertia. These\ncharacters also play a potential role to understand the classification of\nirreducible smooth representations of inner forms of classical groups. We prove\nthe intertwining formula for semisimple characters and an intertwining implies\nconjugacy like theorem. Further we show that endo-parameters for~$G$, i.e.\ninvariants consisting of simple endo-classes and a numerical part, classify the\nintertwining classes of semisimple characters for~$G$. They should be the\ncounter part for restrictions of Langlands-parameters to wild inertia under\nLocal Langlands correspondence.\n",
"title": "Semisimple characters for inner froms I: GL_n(D)"
}
| null | null | null | null | true | null |
9019
| null |
Default
| null | null |
null |
{
"abstract": " We propose a method to build quantum memristors in quantum photonic\nplatforms. We firstly design an effective beam splitter, which is tunable in\nreal-time, by means of a Mach-Zehnder-type array with two equal 50:50 beam\nsplitters and a tunable retarder, which allows us to control its reflectivity.\nThen, we show that this tunable beam splitter, when equipped with weak\nmeasurements and classical feedback, behaves as a quantum memristor. Indeed, in\norder to prove its quantumness, we show how to codify quantum information in\nthe coherent beams. Moreover, we estimate the memory capability of the quantum\nmemristor. Finally, we show the feasibility of the proposed setup in integrated\nquantum photonics.\n",
"title": "Quantum Memristors in Quantum Photonics"
}
| null | null | null | null | true | null |
9020
| null |
Default
| null | null |
null |
{
"abstract": " The exciton spin dynamics are investigated both experimentally and\ntheoretically in two-monolayer-thick GaAs/AlAs quantum wells with an indirect\nband gap and a type-II band alignment. The magnetic-field-induced circular\npolarization of photoluminescence, $P_c$, is studied as function of the\nmagnetic field strength and direction as well as sample temperature. The\nobserved nonmonotonic behaviour of these functions is provided by the interplay\nof bright and dark exciton states contributing to the emission. To interpret\nthe experiment, we have developed a kinetic master equation model which\naccounts for the dynamics of the spin states in this exciton quartet, radiative\nand nonradiative recombination processes, and redistribution of excitons\nbetween these states as result of spin relaxation. The model offers\nquantitative agreement with experiment and allows us to evaluate, for the\nstudied structure, the heavy-hole $g$ factor, $g_{hh}=+3.5$, and the spin\nrelaxation times of electron, $\\tau_{se} = 33~\\mu$s, and hole, $\\tau_{sh} =\n3~\\mu$s, bound in the exciton.\n",
"title": "Spin dynamics and magnetic-field-induced polarization of excitons in ultrathin GaAs/AlAs quantum wells with indirect band gap and type-II band alignment"
}
| null | null | null | null | true | null |
9021
| null |
Default
| null | null |
null |
{
"abstract": " Resonant inelastic x-ray scattering at the N K edge reveals clearly resolved\nharmonics of the anion plane vibrations in the kappa-(BEDT-TTF)2Cu2(CN)3\nspin-liquid insulator. Tuning the incoming light energy at the K edge of two\ndistinct N sites permits to excite different sets of phonon modes. Cyanide CN\nstretching mode is selected at the edge of the ordered N sites which are more\nstrongly connected to the BEDT-TTF molecules, while positionally disordered N\nsites show multi-mode excitation. Combining measurements with calculations on\nan anion plane cluster permits to estimate the sitedependent electron-phonon\ncoupling of the modes related to nitrogen excitation.\n",
"title": "Resonant inelastic x-ray scattering probes the electron-phonon coupling in the spin-liquid kappa-(BEDT-TTF)2Cu2(CN)3"
}
| null | null | null | null | true | null |
9022
| null |
Default
| null | null |
null |
{
"abstract": " We present a dynamic and thermodynamic study of the orientational glass\nformer Freon113 (CCl2F-CClF2) in order to analyze its kinetic and thermodynamic\nfragilities. Freon113 displays internal molecular degrees of freedom which\npromote a complex energy landscape. Experimental specific heat and its\nmicroscopic origin, the vibrational density of states from inelastic neutron\nscattering, together with the orientational dynamics obtained by means of\ndielectric spectroscopy have revealed the highest fragility value, both\nthermodynamic and kinetic, found for this orientational glass former. The\nexcess in both Debye-reduced specific heat and density of states (boson peak)\nevidences the existence of glassy low-energy excitations. We demonstrate that\nearly proposed correlations between the boson peak and the Debye specific heat\nvalue are elusive as revealed by the clear counterexample of the studied case.\n",
"title": "Thermodynamic and kinetic fragility of Freon113: the most fragile plastic crystal"
}
| null | null | null | null | true | null |
9023
| null |
Default
| null | null |
null |
{
"abstract": " Data augmentation is usually used by supervised learning approaches for\noffline writer identification, but such approaches require extra training data\nand potentially lead to overfitting errors. In this study, a semi-supervised\nfeature learning pipeline was proposed to improve the performance of writer\nidentification by training with extra unlabeled data and the original labeled\ndata simultaneously. Specifically, we proposed a weighted label smoothing\nregularization (WLSR) method for data augmentation, which assigned the weighted\nuniform label distribution to the extra unlabeled data. The WLSR method could\nregularize the convolutional neural network (CNN) baseline to allow more\ndiscriminative features to be learned to represent the properties of different\nwriting styles. The experimental results on well-known benchmark datasets\n(ICDAR2013 and CVL) showed that our proposed semi-supervised feature learning\napproach could significantly improve the baseline measurement and perform\ncompetitively with existing writer identification approaches. Our findings\nprovide new insights into offline write identification.\n",
"title": "Semi-supervised Feature Learning For Improving Writer Identification"
}
| null | null | null | null | true | null |
9024
| null |
Default
| null | null |
null |
{
"abstract": " The paper deals with regression problems, in which the nonsmooth target is\nassumed to switch between different operating modes. Specifically, piecewise\nsmooth (PWS) regression considers target functions switching deterministically\nvia a partition of the input space, while switching regression considers\narbitrary switching laws. The paper derives generalization error bounds in\nthese two settings by following the approach based on Rademacher complexities.\nFor PWS regression, our derivation involves a chaining argument and a\ndecomposition of the covering numbers of PWS classes in terms of the ones of\ntheir component functions and the capacity of the classifier partitioning the\ninput space. This yields error bounds with a radical dependency on the number\nof modes. For switching regression, the decomposition can be performed directly\nat the level of the Rademacher complexities, which yields bounds with a linear\ndependency on the number of modes. By using once more chaining and a\ndecomposition at the level of covering numbers, we show how to recover a\nradical dependency. Examples of applications are given in particular for PWS\nand swichting regression with linear and kernel-based component functions.\n",
"title": "Error Bounds for Piecewise Smooth and Switching Regression"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
9025
| null |
Validated
| null | null |
null |
{
"abstract": " Civil Asset Forfeiture (CAF) is a longstanding and controversial legal\nprocess viewed on the one hand as a powerful tool for combating drug crimes and\non the other hand as a violation of the rights of US citizens. Data used to\nsupport both sides of the controversy to date has come from government sources\nrepresenting records of the events at the time of occurrence. Court dockets\nrepresent litigation events initiated following the forfeiture, however, and\ncan thus provide a new perspective on the CAF legal process. This paper will\nshow new evidence supporting existing claims about the growth of the practice\nand bias in its application based on the quantitative analysis of data derived\nfrom these court cases.\n",
"title": "Civil Asset Forfeiture: A Judicial Perspective"
}
| null | null | null | null | true | null |
9026
| null |
Default
| null | null |
null |
{
"abstract": " Modern bio-technologies have produced a vast amount of high-throughput data\nwith the number of predictors far greater than the sample size. In order to\nidentify more novel biomarkers and understand biological mechanisms, it is\nvital to detect signals weakly associated with outcomes among\nultrahigh-dimensional predictors. However, existing screening methods, which\ntypically ignore correlation information, are likely to miss these weak\nsignals. By incorporating the inter-feature dependence, we propose a\ncovariance-insured screening methodology to identify predictors that are\njointly informative but only marginally weakly associated with outcomes. The\nvalidity of the method is examined via extensive simulations and real data\nstudies for selecting potential genetic factors related to the onset of cancer.\n",
"title": "Covariance-Insured Screening"
}
| null | null | null | null | true | null |
9027
| null |
Default
| null | null |
null |
{
"abstract": " We deal with finite dimensional differentiable manifolds. All items are\nconcerned with are differentiable as well. The class of differentiability is\n$C^\\infty$. A metric structure in a vector bundle $E$ is a constant rank\nsymmetric bilinear vector bundle homomorphism of $E\\times E$ in the trivial\nbundle line bundle. We address the question whether a given gauge structure in\n$E$ is metric. That is the main concerns. We use generalized Amari functors of\nthe information geometry for introducing two index functions defined in the\nmoduli space of gauge structures in $E$. Beside we introduce a differential\nequation whose analysis allows to link the new index functions just mentioned\nwith the main concerns. We sketch applications in the differential geometry\ntheory of statistics. Reader interested in a former forum on the question\nwhether a giving connection is metric are referred to appendix.\n",
"title": "Amari Functors and Dynamics in Gauge Structures"
}
| null | null | null | null | true | null |
9028
| null |
Default
| null | null |
null |
{
"abstract": " Nearly all previous work on small-footprint keyword spotting with neural\nnetworks quantify model footprint in terms of the number of parameters and\nmultiply operations for a feedforward inference pass. These values are,\nhowever, proxy measures since empirical performance in actual deployments is\ndetermined by many factors. In this paper, we study the power consumption of a\nfamily of convolutional neural networks for keyword spotting on a Raspberry Pi.\nWe find that both proxies are good predictors of energy usage, although the\nnumber of multiplies is more predictive than the number of model parameters. We\nalso confirm that models with the highest accuracies are, unsurprisingly, the\nmost power hungry.\n",
"title": "An Experimental Analysis of the Power Consumption of Convolutional Neural Networks for Keyword Spotting"
}
| null | null | null | null | true | null |
9029
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we prove a functorial aspect of the formal geometric\nquantization procedure of non-compact spin-c manifolds.\n",
"title": "Formal Geometric Quantization III, Functoriality in the spin-c setting"
}
| null | null | null | null | true | null |
9030
| null |
Default
| null | null |
null |
{
"abstract": " When using risk or dependence measures based on a given underlying model, it\nis essential to be able to quantify the sensitivity or robustness of these\nmeasures with respect to the model parameters. In this paper, we consider an\nunderlying model which is very popular in spatial extremes, the Smith\nmax-stable random field. We study the sensitivity properties of risk or\ndependence measures based on the values of this field at a finite number of\nlocations. Max-stable fields play a key role, e.g., in the modelling of natural\ndisasters. As their multivariate density is generally not available for more\nthan three locations, the Likelihood Ratio Method cannot be used to estimate\nthe derivatives of the risk measures with respect to the model parameters.\nThus, we focus on a pathwise method, the Infinitesimal Perturbation Analysis\n(IPA). We provide a convenient and tractable sufficient condition for\nperforming IPA, which is intricate to obtain because of the very structure of\nmax-stable fields involving pointwise maxima over an infinite number of random\nfunctions. IPA enables the consistent estimation of the considered measures'\nderivatives with respect to the parameters characterizing the spatial\ndependence. We carry out a simulation study which shows that the approach\nperforms well in various configurations.\n",
"title": "Infinitesimal perturbation analysis for risk measures based on the Smith max-stable random field"
}
| null | null | null | null | true | null |
9031
| null |
Default
| null | null |
null |
{
"abstract": " A two-way relay non-orthogonal multiple access (TWR-NOMA) system is\ninvestigated, where two groups of NOMA users exchange messages with the aid of\none half-duplex (HD) decode-and-forward (DF) relay. Since the\nsignal-plus-interference-to-noise ratios (SINRs) of NOMA signals mainly depend\non effective successive interference cancellation (SIC) schemes, imperfect SIC\n(ipSIC) and perfect SIC (pSIC) are taken into account. In order to characterize\nthe performance of TWR-NOMA systems, we first derive closed-form expressions\nfor both exact and asymptotic outage probabilities of NOMA users' signals with\nipSIC/pSIC. Based on the derived results, the diversity order and throughput of\nthe system are examined. Then we study the ergodic rates of users' signals by\nproviding the asymptotic analysis in high SNR regimes. Lastly, numerical\nsimulations are provided to verify the analytical results and show that: 1)\nTWR-NOMA is superior to TWR-OMA in terms of outage probability in low SNR\nregimes; 2) Due to the impact of interference signal (IS) at the relay, error\nfloors and throughput ceilings exist in outage probabilities and ergodic rates\nfor TWR-NOMA, respectively; and 3) In delay-limited transmission mode, TWR-NOMA\nwith ipSIC and pSIC have almost the same energy efficiency. However, in\ndelay-tolerant transmission mode, TWR-NOMA with pSIC is capable of achieving\nlarger energy efficiency compared to TWR-NOMA with ipSIC.\n",
"title": "Modeling and Analysis of Two-Way Relay Non-Orthogonal Multiple Access Systems"
}
| null | null | null | null | true | null |
9032
| null |
Default
| null | null |
null |
{
"abstract": " We show that two involutions on the variety $N_n^+$ of upper triangular\ntotally positive matrices are related, on the one hand, to the tetrahedron\nequation and, on the other hand, to the action of the symmetric group $S_3$ on\nsome subvariety of $N_n^+$ and on the set of certain functions on $N_n^+$.\nUsing these involutions, we obtain a family of dilogarithm identities involving\nminors of totally positive matrices. These identities admit a form manifestly\ninvariant under the action of the symmetric group $S_3$.\n",
"title": "Totally positive matrices and dilogarithm identities"
}
| null | null | null | null | true | null |
9033
| null |
Default
| null | null |
null |
{
"abstract": " Li and Wei (2009) studied the density of zeros of Gaussian harmonic\npolynomials with independent Gaussian coefficients. They derived a formula for\nthe expected number of zeros of random harmonic polynomials as well as\nasymptotics for the case that the polynomials are drawn from the Kostlan\nensemble. In this paper we extend their work to cover the case that the\npolynomials are drawn from the Weyl ensemble by deriving asymptotics for this\nclass of harmonic polynomials.\n",
"title": "On the zeros of random harmonic polynomials: the Weyl model"
}
| null | null | null | null | true | null |
9034
| null |
Default
| null | null |
null |
{
"abstract": " Deforestation detection using satellite images can make an important\ncontribution to forest management. Current approaches can be broadly divided\ninto those that compare two images taken at similar periods of the year and\nthose that monitor changes by using multiple images taken during the growing\nseason. The CMFDA algorithm described in Zhu et al. (2012) is an algorithm that\nbuilds on the latter category by implementing a year-long, continuous,\ntime-series based approach to monitoring images. This algorithm was developed\nfor 30m resolution, 16-day frequency reflectance data from the Landsat\nsatellite. In this work we adapt the algorithm to 1km, 16-day frequency\nreflectance data from the modis sensor aboard the Terra satellite. The CMFDA\nalgorithm is composed of two submodels which are fitted on a pixel-by-pixel\nbasis. The first estimates the amount of surface reflectance as a function of\nthe day of the year. The second estimates the occurrence of a deforestation\nevent by comparing the last few predicted and real reflectance values. For this\ncomparison, the reflectance observations for six different bands are first\ncombined into a forest index. Real and predicted values of the forest index are\nthen compared and high absolute differences for consecutive observation dates\nare flagged as deforestation events. Our adapted algorithm also uses the two\nmodel framework. However, since the modis 13A2 dataset used, includes\nreflectance data for different spectral bands than those included in the\nLandsat dataset, we cannot construct the forest index. Instead we propose two\ncontrasting approaches: a multivariate and an index approach similar to that of\nCMFDA.\n",
"title": "Online deforestation detection"
}
| null | null | null | null | true | null |
9035
| null |
Default
| null | null |
null |
{
"abstract": " Distributed Computation has been a recent trend in engineering research.\nParallel Computation is widely used in different areas of Data Mining, Image\nProcessing, Simulating Models, Aerodynamics and so forth. One of the major\nusage of Parallel Processing is widely implemented for clustering the satellite\nimages of size more than dimension of 1000x1000 in a legacy system. This paper\nmainly focuses on the different approaches of parallel block processing such as\nrow-shaped, column-shaped and square-shaped. These approaches are applied for\nclassification problem. These approaches is applied to the K-Means clustering\nalgorithm as this is widely used for the detection of features for high\nresolution orthoimagery satellite images. The different approaches are\nanalyzed, which lead to reduction in execution time and resulted the influence\nof improvement in performance measurement compared to sequential K-Means\nClustering algorithm.\n",
"title": "Analysis of Different Approaches of Parallel Block Processing for K-Means Clustering Algorithm"
}
| null | null | null | null | true | null |
9036
| null |
Default
| null | null |
null |
{
"abstract": " [Context] The use of defect prediction models, such as classifiers, can\nsupport testing resource allocations by using data of the previous releases of\nthe same project for predicting which software components are likely to be\ndefective. A validation technique, hereinafter technique defines a specific way\nto split available data in training and test sets to measure a classifier\naccuracy. Time-series techniques have the unique ability to preserve the\ntemporal order of data; i.e., preventing the testing set to have data\nantecedent to the training set. [Aim] The aim of this paper is twofold: first\nwe check if there is a difference in the classifiers accuracy measured by\ntime-series versus non-time-series techniques. Afterward, we check for a\npossible reason for this difference, i.e., if defect rates change across\nreleases of a project. [Method] Our method consists of measuring the accuracy,\ni.e., AUC, of 10 classifiers on 13 open and two closed projects by using three\nvalidation techniques, namely cross validation, bootstrap, and walk-forward,\nwhere only the latter is a time-series technique. [Results] We find that the\nAUC of the same classifier used on the same project and measured by 10-fold\nvaries compared to when measured by walk-forward in the range [-0.20, 0.22],\nand it is statistically different in 45% of the cases. Similarly, the AUC\nmeasured by bootstrap varies compared to when measured by walk-forward in the\nrange [-0.17, 0.43], and it is statistically different in 56% of the cases.\n[Conclusions] We recommend choosing the technique to be used by carefully\nconsidering the conclusions to draw, the property of the available datasets,\nand the level of realism with the classifier usage scenario.\n",
"title": "Preserving Order of Data When Validating Defect Prediction Models"
}
| null | null | null | null | true | null |
9037
| null |
Default
| null | null |
null |
{
"abstract": " Graphlets are small connected induced subgraphs of a larger graph $G$.\nGraphlets are now commonly used to quantify local and global topology of\nnetworks in the field. Methods exist to exhaustively enumerate all graphlets\n(and their orbits) in large networks as efficiently as possible using orbit\ncounting equations. However, the number of graphlets in $G$ is exponential in\nboth the number of nodes and edges in $G$. Enumerating them all is already\nunacceptably expensive on existing large networks, and the problem will only\nget worse as networks continue to grow in size and density. Here we introduce\nan efficient method designed to aid statistical sampling of graphlets up to\nsize $k=8$ from a large network. We define graphettes as the generalization of\ngraphlets allowing for disconnected graphlets. Given a particular (undirected)\ngraphette $g$, we introduce the idea of the canonical graphette $\\mathcal K(g)$\nas a representative member of the isomorphism group $Iso(g)$ of $g$. We compute\nthe mapping $\\mathcal K$, in the form of a lookup table, from all\n$2^{k(k-1)/2}$ undirected graphettes $g$ of size $k\\le 8$ to their canonical\nrepresentatives $\\mathcal K(g)$, as well as the permutation that transforms $g$\nto $\\mathcal K(g)$. We also compute all automorphism orbits for each canonical\ngraphette. Thus, given any $k\\le 8$ nodes in a graph $G$, we can in constant\ntime infer which graphette it is, as well as which orbit each of the $k$ nodes\nbelongs to. Sampling a large number $N$ of such $k$-sets of nodes provides an\napproximation of both the distribution of graphlets and orbits across $G$, and\nthe orbit degree vector at each node.\n",
"title": "Graphettes: Constant-time determination of graphlet and orbit identity including (possibly disconnected) graphlets up to size 8"
}
| null | null | null | null | true | null |
9038
| null |
Default
| null | null |
null |
{
"abstract": " We review, from a didactic point of view, the definition of a toric section\nand the different shapes it can take. We'll then discuss some properties of\nthis curve, investigate its analogies and differences with the most renowned\nconic section and show how to build its general quartic equation. A curious and\nunexpected result was to find that, with some algebraic manipulation, a toric\nsection can also be obtained as the intersection of a cylinder with a cone.\nFinally we'll show how it is possible to construct and represent toric sections\nin the 3D Graphics view of Geogebra. In the article only elementary algebra is\nused, and the requirements to follow it are just some notion of goniometry and\nof tridimensional analytic geometry.\n",
"title": "The toric sections: a simple introduction"
}
| null | null | null | null | true | null |
9039
| null |
Default
| null | null |
null |
{
"abstract": " We demonstrate how one can see quantization of geometry, and quantum\nalgebraic structure in supersymmetric gauge theory.\n",
"title": "Quantum Field Theory, Quantum Geometry, and Quantum Algebras"
}
| null | null | null | null | true | null |
9040
| null |
Default
| null | null |
null |
{
"abstract": " Embedded, continual learning for autonomous and adaptive behavior is a key\napplication of neuromorphic hardware. However, neuromorphic implementations of\nembedded learning at large scales that are both flexible and efficient have\nbeen hindered by a lack of a suitable algorithmic framework. As a result, the\nmost neuromorphic hardware is trained off-line on large clusters of dedicated\nprocessors or GPUs and transferred post hoc to the device. We address this by\nintroducing the neural and synaptic array transceiver (NSAT), a neuromorphic\ncomputational framework facilitating flexible and efficient embedded learning\nby matching algorithmic requirements and neural and synaptic dynamics. NSAT\nsupports event-driven supervised, unsupervised and reinforcement learning\nalgorithms including deep learning. We demonstrate the NSAT in a wide range of\ntasks, including the simulation of Mihalas-Niebur neuron, dynamic neural\nfields, event-driven random back-propagation for event-based deep learning,\nevent-based contrastive divergence for unsupervised learning, and voltage-based\nlearning rules for sequence learning. We anticipate that this contribution will\nestablish the foundation for a new generation of devices enabling adaptive\nmobile systems, wearable devices, and robots with data-driven autonomy.\n",
"title": "Neural and Synaptic Array Transceiver: A Brain-Inspired Computing Framework for Embedded Learning"
}
| null | null | null | null | true | null |
9041
| null |
Default
| null | null |
null |
{
"abstract": " This paper proposes the application of Discrete Wavelet Transform (DWT) to\ndetect the QRS (ECG is characterized by a recurrent wave sequence of P, QRS and\nT-wave) of an electrocardiogram (ECG) signal. Wavelet Transform provides\nlocalization in both time and frequency. In preprocessing stage, DWT is used to\nremove the baseline wander in the ECG signal. The performance of the algorithm\nof QRS detection is evaluated against the standard MIT BIH (Massachusetts\nInstitute of Technology, Beth Israel Hospital) Arrhythmia database. The average\nQRS complexes detection rate of 98.1 % is achieved.\n",
"title": "Discrete Wavelet Transform Based Algorithm for Recognition of QRS Complexes"
}
| null | null |
[
"Computer Science"
] | null | true | null |
9042
| null |
Validated
| null | null |
null |
{
"abstract": " Context. Upcoming weak lensing surveys such as Euclid will provide an\nunprecedented opportunity to quantify the geometry and topology of the cosmic\nweb, in particular in the vicinity of lensing clusters. Aims. Understanding the\nconnectivity of the cosmic web with unbiased mass tracers, such as weak\nlensing, is of prime importance to probe the underlying cosmology, seek\ndynamical signatures of dark matter, and quantify environmental effects on\ngalaxy formation. Methods. Mock catalogues of galaxy clusters are extracted\nfrom the N-body PLUS simulation. For each cluster, the aperture multipolar\nmoments of the convergence are calculated in two annuli (inside and outside the\nvirial radius). By stacking their modulus, a statistical estimator is built to\ncharacterise the angular mass distribution around clusters. The moments are\ncompared to predictions from perturbation theory and spherical collapse.\nResults. The main weakly chromatic excess of multipolar power on large scales\nis understood as arising from the contraction of the primordial cosmic web\ndriven by the growing potential well of the cluster. Besides this boost, the\nquadrupole prevails in the cluster (ellipsoidal) core, while at the outskirts,\nharmonic distortions are spread on small angular modes, and trace the\nnon-linear sharpening of the filamentary structures. Predictions for the signal\namplitude as a function of the cluster-centric distance, mass, and redshift are\npresented. The prospects of measuring this signal are estimated for current and\nfuture lensing data sets. Conclusions. The Euclid mission should provide all\nthe necessary information for studying the cosmic evolution of the connectivity\nof the cosmic web around lensing clusters using multipolar moments and probing\nunique signatures of, for example, baryons and warm dark matter.\n",
"title": "Multipolar moments of weak lensing signal around clusters. Weighing filaments in harmonic space"
}
| null | null | null | null | true | null |
9043
| null |
Default
| null | null |
null |
{
"abstract": " We study charge and spin transport along grain boundaries in single layer\ngraphene in the presence of a quantizing magnetic field. Transport states in a\ngrain boundary are produced by hybridization of Landau zero modes with\ninterfacial states. In selected energy regimes quantum Hall edge states can be\ndeflected either fully or partially into grain boundary states. The degree of\nedge state deflection is studied in the nonlocal conductance and in the shot\nnoise. We also consider the possibility of grain boundaries as gate-switchable\nspin filters, a functionality enabled by counterpropagating transport channels\nlaterally confined in the grain boundary.\n",
"title": "Charge and spin transport on graphene grain boundaries in a quantizing magnetic field"
}
| null | null | null | null | true | null |
9044
| null |
Default
| null | null |
null |
{
"abstract": " In Lagrangian meshfree methods, the underlying spatial discretization,\nreferred to as a point cloud or a particle cloud, moves with the flow velocity.\nIn this paper, we consider different numerical methods of performing this\nmovement of points or particles. The movement is most commonly done by a first\norder method, which assumes the velocity to be constant within a time step. We\nshow that this method is very inaccurate and that it introduces volume and mass\nconservation errors. We further propose new methods for the same which\nprescribe an additional ODE system that describes the characteristic velocity.\nMovement is then performed along this characteristic velocity. The first new\nway of moving points is an extension of mesh-based streamline tracing ideas to\nmeshfree methods. In the second way, the movement is done based on the\ndifference in approximated streamlines between two time levels, which\napproximates the pathlines in unsteady flow. Numerical comparisons show these\nmethod to be vastly superior to the conventionally used first order method.\n",
"title": "Point Cloud Movement For Fully Lagrangian Meshfree Methods"
}
| null | null | null | null | true | null |
9045
| null |
Default
| null | null |
null |
{
"abstract": " We consider the problem of optimally designing a body wireless sensor\nnetwork, while taking into account the uncertainty of data generation of\nbiosensors. Since the related min-max robustness Integer Linear Programming\n(ILP) problem can be difficult to solve even for state-of-the-art commercial\noptimization solvers, we propose an original heuristic for its solution. The\nheuristic combines deterministic and probabilistic variable fixing strategies,\nguided by the information coming from strengthened linear relaxations of the\nILP robust model, and includes a very large neighborhood search for reparation\nand improvement of generated solutions, formulated as an ILP problem solved\nexactly. Computational tests on realistic instances show that our heuristic\nfinds solutions of much higher quality than a state-of-the-art solver and than\nan effective benchmark heuristic.\n",
"title": "A fast ILP-based Heuristic for the robust design of Body Wireless Sensor Networks"
}
| null | null | null | null | true | null |
9046
| null |
Default
| null | null |
null |
{
"abstract": " The negatively charged nitrogen-vacancy (NV-) center in diamond is a\npromising candidate for many quantum applications. Here, we examine the\nsplitting and broadening of the center's infrared (IR) zero-phonon line (ZPL).\nWe develop a model for these effects that accounts for the strain induced by\nphoto-dependent microscopic distributions of defects. We apply this model to\ninterpret observed variations of the IR ZPL shape with temperature and\nphotoexcitation conditions. We identify an anomalous temperature dependent\nbroadening mechanism and that defects other than the substitutional nitrogen\ncenter significantly contribute to strain broadening. The former conclusion\nsuggests the presence of a strong Jahn-Teller effect in the center's singlet\nlevels and the latter indicates that major sources of broadening are yet to be\nidentified. These conclusions have important implications for the understanding\nof the center and the engineering of diamond quantum devices. Finally, we\npropose that the IR ZPL can be used as a sensitive spectroscopic tool for\nprobing microscopic strain fields and performing defect tomography.\n",
"title": "Strain broadening of the 1042-nm zero-phonon line of the NV- center in diamond: a promising spectroscopic tool for defect tomography"
}
| null | null | null | null | true | null |
9047
| null |
Default
| null | null |
null |
{
"abstract": " Convolution Neural Network (CNN) has gained tremendous success in computer\nvision tasks with its outstanding ability to capture the local latent features.\nRecently, there has been an increasing interest in extending convolution\noperations to the non-Euclidean geometry. Although various types of convolution\noperations have been proposed for graphs or manifolds, their connections with\ntraditional convolution over grid-structured data are not well-understood. In\nthis paper, we show that depthwise separable convolution can be successfully\ngeneralized for the unification of both graph-based and grid-based convolution\nmethods. Based on this insight we propose a novel Depthwise Separable Graph\nConvolution (DSGC) approach which is compatible with the tradition convolution\nnetwork and subsumes existing convolution methods as special cases. It is\nequipped with the combined strengths in model expressiveness, compatibility\n(relatively small number of parameters), modularity and computational\nefficiency in training. Extensive experiments show the outstanding performance\nof DSGC in comparison with strong baselines on multi-domain benchmark datasets.\n",
"title": "Learning Depthwise Separable Graph Convolution from Data Manifold"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
9048
| null |
Validated
| null | null |
null |
{
"abstract": " We present a catalogue of candidate H{\\alpha} emission and absorption line\nsources and blue objects in the Galactic Bulge Survey (GBS) region. We use a\npoint source catalogue of the GBS fields (two strips of (l x b) = (6 x 1)\ndegrees centred at b = 1.5 above and below the Galactic centre), covering the\nmagnitude range 16 < r' < 22.5. We utilize (r'-i', r'-H{\\alpha}) colour-colour\ndiagrams to select H{\\alpha} emission and absorption line candidates, and also\nidentify blue objects (compared to field stars) using the r'-i' colour index.\nWe identify 1337 H{\\alpha} emission line candidates and 336 H{\\alpha}\nabsorption line candidates. These catalogues likely contain a plethora of\nsources, ranging from active (binary) stars, early-type emission line objects,\ncataclysmic variables (CVs) and low-mass X-ray binaries (LMXBs) to background\nactive galactic nuclei (AGN). The 389 blue objects we identify are likely\nsystems containing a compact object, such as CVs, planetary nebulae and LMXBs.\nHot subluminous dwarfs (sdO/B stars) are also expected to be found as blue\noutliers. Crossmatching our outliers with the GBS X-ray catalogue yields\nsixteen sources, including seven (magnetic) CVs and one qLMXB candidate among\nthe emission line candidates, and one background AGN for the absorption line\ncandidates. One of the blue outliers is a high state AM CVn system.\nSpectroscopic observations combined with the multi-wavelength coverage of this\narea, including X-ray, ultraviolet and (time-resolved) optical and infrared\nobservations, can be used to further constrain the nature of individual\nsources.\n",
"title": "Candidate Hα emission and absorption line sources in the Galactic Bulge Survey"
}
| null | null | null | null | true | null |
9049
| null |
Default
| null | null |
null |
{
"abstract": " Using an age of information (AoI) metric, we examine the transmission of\ncoded updates through a binary erasure channel to a monitor/receiver. We start\nby deriving the average status update age of an infinite incremental redundancy\n(IIR) system in which the transmission of a k-symbol update continuesuntil k\nsymbols are received. This system is then compared to a fixed redundancy (FR)\nsystem in which each update is transmitted as an n symbol packet and the packet\nis successfully received if and only if at least k symbols are received. If\nfewer than k symbols are received, the update is discarded. Unlike the IIR\nsystem, the FR system requires no feedback from the receiver. For a single\nmonitor system, we show that tuning the redundancy to the symbol erasure rate\nenables the FR system to perform as well as the IIR system. As the number of\nmonitors is increased, the FR system outperforms the IIR system that guarantees\ndelivery of all updates to all monitors.\n",
"title": "Timely Updates over an Erasure Channel"
}
| null | null |
[
"Computer Science"
] | null | true | null |
9050
| null |
Validated
| null | null |
null |
{
"abstract": " We analyze the optical continuum of star-forming galaxies in SDSS by fitting\nstacked spectra with stellar population synthesis models to investigate the\nrelation between stellar mass, stellar metallicity, dust attenuation and star\nformation rate. We fit models calculated with star formation and chemical\nevolution histories that are derived empirically from multi-epoch observations\nof the stellar mass---star formation rate and the stellar mass---gas-phase\nmetallicity relations, respectively. We also fit linear combinations of single\nburst models with a range of metallicities and ages. Star formation and\nchemical evolution histories are unconstrained for these models. The stellar\nmass---stellar metallicity relations obtained from the two methods agree with\nthe relation measured from individual supergiant stars in nearby galaxies.\nThese relations are also consistent with the relation obtained from emission\nline analysis of gas-phase metallicity after accounting for systematic offsets\nin the gas-phase-metallicity. We measure dust attenuation of the stellar\ncontinuum and show that its dependence on stellar mass and star formation rate\nis consistent with previously reported results derived from nebular emission\nlines. However, stellar continuum attenuation is smaller than nebular emission\nline attenuation. The continuum-to-nebular attenuation ratio depends on stellar\nmass and is smaller in more massive galaxies. Our consistent analysis of\nstellar continuum and nebular emission lines paves the way for a comprehensive\ninvestigation of stellar metallicities of star-forming and quiescent galaxies.\n",
"title": "Stellar Absorption Line Analysis of Local Star-Forming Galaxies: The Relation Between Stellar Mass, Metallicity, Dust Attenuation and Star Formation Rate"
}
| null | null | null | null | true | null |
9051
| null |
Default
| null | null |
null |
{
"abstract": " The Eigenvector Method for Umbrella Sampling (EMUS) belongs to a popular\nclass of methods in statistical mechanics which adapt the principle of\nstratified survey sampling to the computation of free energies. By theoretical\nanalysis and numerical experiments, we demonstrate that EMUS is an efficient\ngeneral method for computing averages with respect to arbitrary target\ndistributions. We show that EMUS can be dramatically more efficient than direct\nMCMC when the target distribution is multimodal or when the goal is to compute\ntail probabilities.\n",
"title": "Stratification as a general variance reduction method for Markov chain Monte Carlo"
}
| null | null | null | null | true | null |
9052
| null |
Default
| null | null |
null |
{
"abstract": " Markov chain Monte Carlo (MCMC) methods are widely used in machine learning.\nOne of the major problems with MCMC is the question of how to design chains\nthat mix fast over the whole space; in particular, how to select the parameters\nof an MCMC algorithm. Here we take a different approach and, similarly to\nparallel MCMC methods, instead of trying to find a single chain to sample from\nthe whole distribution, we combine samples from several chains run in parallel,\neach exploring only a few modes. The chains are prioritized based on the kernel\nStein discrepancy, which provides a good measure of performance locally. The\nsamples from the independent chains are combined using a novel technique for\nestimating the probability of different regions of the sample space.\nExperimental results demonstrate that the resulting algorithm may provide\nsignificant speedups in different sampling problems. Most importantly, when\ncombined with the state-of-the-art NUTS algorithm as the base MCMC sampler, our\nalgorithm remained competitive with the basic version of NUTS on sampling from\nunimodal distributions, while significantly outperformed state-of-the-art\ncompetitors on synthetic multimodal problems as well as on a challenging sensor\nlocalization task.\n",
"title": "Adaptive MCMC via Combining Local Samplers"
}
| null | null | null | null | true | null |
9053
| null |
Default
| null | null |
null |
{
"abstract": " We describe the open-source global fitting package GAMBIT: the Global And\nModular Beyond-the-Standard-Model Inference Tool. GAMBIT combines extensive\ncalculations of observables and likelihoods in particle and astroparticle\nphysics with a hierarchical model database, advanced tools for automatically\nbuilding analyses of essentially any model, a flexible and powerful system for\ninterfacing to external codes, a suite of different statistical methods and\nparameter scanning algorithms, and a host of other utilities designed to make\nscans faster, safer and more easily-extendible than in the past. Here we give a\ndetailed description of the framework, its design and motivation, and the\ncurrent models and other specific components presently implemented in GAMBIT.\nAccompanying papers deal with individual modules and present first GAMBIT\nresults. GAMBIT can be downloaded from gambit.hepforge.org.\n",
"title": "GAMBIT: The Global and Modular Beyond-the-Standard-Model Inference Tool"
}
| null | null | null | null | true | null |
9054
| null |
Default
| null | null |
null |
{
"abstract": " The complexity of testing whether a graph contains an induced odd cycle of\nlength at least five is currently unknown. In this paper we show that this can\nbe done in polynomial time if the input graph has no induced subgraph\nisomorphic to the bull (a triangle with two disjoint pendant edges).\n",
"title": "Odd holes in bull-free graphs"
}
| null | null | null | null | true | null |
9055
| null |
Default
| null | null |
null |
{
"abstract": " It is well known that external magnetic fields and magnetic moments of\nimpurities both suppress superconductivity. Here, we demonstrate that their\ncombined effect enhances the superconductivity of a few atomic layer thick Pb\nfilms grown on a cleaved GaAs(110) surface. A Ce-doped film, where\nsuperconductivity is totally suppressed at zero-field, actually turns\nsuperconducting when an external magnetic field is applied parallel to the\nconducting plane. For films with Mn adatoms, the screening of the magnetic\nmoment by conduction electrons, i.e., the Kondo singlet formation, becomes\nimportant. We found that the degree of screening can be reduced by capping the\nPb film with a Au layer, and observed the positive magnetic field dependence of\nthe superconducting transition temperature.\n",
"title": "Magnetic-Field-Induced Superconductivity in Ultrathin Pb Films with Magnetic Impurities"
}
| null | null |
[
"Physics"
] | null | true | null |
9056
| null |
Validated
| null | null |
null |
{
"abstract": " We completely characterize the unimodal category for functions $f:\\mathbb\nR\\to[0,\\infty)$ using a decomposition theorem obtained by generalizing the\nsweeping algorithm of Baryshnikov and Ghrist. We also give a characterization\nof the unimodal category for functions $f:S^1\\to[0,\\infty)$ and provide an\nalgorithm to compute the unimodal category of such a function in the case of\nfinitely many critical points.\nWe then turn to the monotonicity conjecture of Baryshnikov and Ghrist. We\nshow that this conjecture is true for functions on $\\mathbb R$ and $S^1$ using\nthe above characterizations and that it is false on certain graphs and on the\nEuclidean plane by providing explicit counterexamples. We also show that it\nholds for functions on the Euclidean plane whose Morse-Smale graph is a tree\nusing a result of Hickok, Villatoro and Wang.\n",
"title": "Unimodal Category and the Monotonicity Conjecture"
}
| null | null | null | null | true | null |
9057
| null |
Default
| null | null |
null |
{
"abstract": " Counting formulae for general primary fields in free four dimensional\nconformal field theories of scalars, vectors and matrices are derived. These\nare specialised to count primaries which obey extremality conditions defined in\nterms of the dimensions and left or right spins (i.e. in terms of relations\nbetween the charges under the Cartan subgroup of $SO(4,2)$). The construction\nof primary fields for scalar field theory is mapped to a problem of determining\nmulti-variable polynomials subject to a system of symmetry and differential\nconstraints. For the extremal primaries, we give a construction in terms of\nholomorphic polynomial functions on permutation orbifolds, which are shown to\nbe Calabi-Yau spaces.\n",
"title": "Holomorphic primary fields in free CFT4 and Calabi-Yau orbifolds"
}
| null | null |
[
"Mathematics"
] | null | true | null |
9058
| null |
Validated
| null | null |
null |
{
"abstract": " Paraphrase generation is an important problem in NLP, especially in question\nanswering, information retrieval, information extraction, conversation systems,\nto name a few. In this paper, we address the problem of generating paraphrases\nautomatically. Our proposed method is based on a combination of deep generative\nmodels (VAE) with sequence-to-sequence models (LSTM) to generate paraphrases,\ngiven an input sentence. Traditional VAEs when combined with recurrent neural\nnetworks can generate free text but they are not suitable for paraphrase\ngeneration for a given sentence. We address this problem by conditioning the\nboth, encoder and decoder sides of VAE, on the original sentence, so that it\ncan generate the given sentence's paraphrases. Unlike most existing models, our\nmodel is simple, modular and can generate multiple paraphrases, for a given\nsentence. Quantitative evaluation of the proposed method on a benchmark\nparaphrase dataset demonstrates its efficacy, and its performance improvement\nover the state-of-the-art methods by a significant margin, whereas qualitative\nhuman evaluation indicate that the generated paraphrases are well-formed,\ngrammatically correct, and are relevant to the input sentence. Furthermore, we\nevaluate our method on a newly released question paraphrase dataset, and\nestablish a new baseline for future research.\n",
"title": "A Deep Generative Framework for Paraphrase Generation"
}
| null | null | null | null | true | null |
9059
| null |
Default
| null | null |
null |
{
"abstract": " Collective motion of chemotactic bacteria as E. Coli relies, at the\nindividual level, on a continuous reorientation by runs and tumbles. It has\nbeen established that the length of run is decided by a stiff response to a\ntemporal sensingof chemical cues along the pathway.We describe a novel\nmechanism for pattern formation stemming from the stiffness of chemotactic\nresponse relying on a kinetic chemotaxis model which includes a recently\ndiscovered formalism for the bacterial chemotaxis. We prove instability both\nfor amicroscopic description in the space-velocity space and for the\nmacroscopic equation, a flux-limited Keller-Segel equation, which has attracted\nmuch attention recently.A remarkable property is that the unstable frequencies\nremain bounded, as it is the case in Turing instability. Numerical\nillustrations based on a powerful Monte Carlo method show that the stationary\nhomogeneous state of population density isdestabilized and periodic patterns\nare generated in realistic ranges of parameters. These theoretical developments\nare in accordance with several biological observations.\n",
"title": "Stiff-response-induced instability for chemotactic bacteria and flux-limited Keller-Segel equation"
}
| null | null | null | null | true | null |
9060
| null |
Default
| null | null |
null |
{
"abstract": " Landau level mixing plays an important role in the Pfaffian (or\nanti-Pfaffian) states. In ZnO the Landau level gap is essentially an order of\nmagnitude smaller than that in a GaAs quantum well. We introduce the screened\nCoulomb interaction in a single Landau level to tackle that situation. Here we\nstudy the overlap of the ground state and the Pfaffian (or anti-Pfaffian) state\nat evendenominator fractional quantum Hall (FQH) states present in ZnO. The\noverlap is strongly system size-dependent which suggests a newly proposed\nparticle-hole symmetry Pfaffian ground state in the extreme Landau level mixing\nlimit. When the ratio of Coulomb interaction to the Landau level gap \\k{appa}\nvaries, we find a possible topological phase transition in the range 2 <\n\\k{appa} < 3, which was actually observed in an experiment. We then study how\nthe width of quantum well combined with screening influences the overlap.\n",
"title": "The Pfaffian state in an electron gas with small Landau level gaps"
}
| null | null | null | null | true | null |
9061
| null |
Default
| null | null |
null |
{
"abstract": " Shear dilation based hydraulic stimulations enable exploitation of geothermal\nenergy from reservoirs with inadequate initial permeability. While contributing\nto enhancing the reservoir's permeability, hydraulic stimulation processes may\nlead to undesired seismic activity. Here, we present a three dimensional\nnumerical model aiming to increase understanding of this mechanism and its\nconsequences. The fractured reservoir is modeled as a network of explicitly\nrepresented large scale fractures immersed in a permeable rock matrix. The\nnumerical formulation is constructed by coupling three physical processes:\nfluid flow, fracture deformation, and rock matrix deformation. For flow\nsimulations, the discrete fracture matrix model is used, which allows the fluid\ntransport from high permeable conductive fractures to the rock matrix and vice\nversa. The mechanical behavior of the fractures is modeled using a hyperbolic\nmodel with reversible and irreversible deformations. Linear elasticity is\nassumed for the mechanical deformation and stress alteration of the rock\nmatrix. Fractures are modeled as lower dimensional surfaces embodied in the\ndomain, subjected to specific governing equations for their deformation along\nthe tangential and normal directions. Both the fluid flow and momentum balance\nequations are approximated by finite volume discretizations. The new numerical\nmodel is demonstrated considering a three dimensional fractured formation with\na network of 20 explicitly represented fractures. The effects of fluid exchange\nbetween fractures and rock matrix on the permeability evolution and the\ngenerated seismicity are examined for test cases resembling realistic reservoir\nconditions.\n",
"title": "Three-Dimensional Numerical Modeling of Shear Stimulation of Naturally Fractured Reservoirs"
}
| null | null | null | null | true | null |
9062
| null |
Default
| null | null |
null |
{
"abstract": " We treat the emerging power systems with direct current (DC) MicroGrids,\ncharacterized with high penetration of power electronic converters. We rely on\nthe power electronics to propose a decentralized solution for autonomous\nlearning of and adaptation to the operating conditions of the DC Mirogrids; the\ngoal is to eliminate the need to rely on an external communication system for\nsuch purpose. The solution works within the primary droop control loops and\nuses only local bus voltage measurements. Each controller is able to estimate\n(i) the generation capacities of power sources, (ii) the load demands, and\n(iii) the conductances of the distribution lines. To define a well-conditioned\nestimation problem, we employ decentralized strategy where the primary droop\ncontrollers temporarily switch between operating points in a coordinated\nmanner, following amplitude-modulated training sequences. We study the use of\nthe estimator in a decentralized solution of the Optimal Economic Dispatch\nproblem. The evaluations confirm the usefulness of the proposed solution for\nautonomous MicroGrid operation.\n",
"title": "Decentralized DC MicroGrid Monitoring and Optimization via Primary Control Perturbations"
}
| null | null | null | null | true | null |
9063
| null |
Default
| null | null |
null |
{
"abstract": " Avian Influenza breakouts cause millions of dollars in damage each year\nglobally, especially in Asian countries such as China and South Korea. The\nimpact magnitude of a breakout directly correlates to time required to fully\nunderstand the influenza virus, particularly the interspecies pathogenicity.\nThe procedure requires laboratory tests that require resources typically\nlacking in a breakout emergency. In this study, we propose new quantitative\nmethods utilizing machine learning and deep learning to correctly classify host\nspecies given raw DNA sequence data of the influenza virus, and provide\nprobabilities for each classification. The best deep learning models achieve\ntop-1 classification accuracy of 47%, and top-3 classification accuracy of 82%,\non a dataset of 11 host species classes.\n",
"title": "AI4AI: Quantitative Methods for Classifying Host Species from Avian Influenza DNA Sequence"
}
| null | null | null | null | true | null |
9064
| null |
Default
| null | null |
null |
{
"abstract": " A new approach to Jiu-Kang Yu's construction of tame supercuspidal\nrepresentations of $p$-adic reductive groups is presented. Connections with the\ntheory of cuspidal Deligne-Lusztig representations of finite groups of Lie type\nare also discussed.\n",
"title": "Constructing tame supercuspidal representations"
}
| null | null | null | null | true | null |
9065
| null |
Default
| null | null |
null |
{
"abstract": " We review some cohomological aspects of complex and hypercomplex manifolds\nand underline the differences between both realms. Furthermore, we try to\nhighlight the similarities between compact complex surfaces on one hand and\ncompact hypercomplex manifolds of real dimension 8 with holonomy of the Obata\nconnection in SL(2,H) on the other hand.\n",
"title": "Cohomologies on hypercomplex manifolds"
}
| null | null | null | null | true | null |
9066
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we study different questions concerning automorphisms of\nquandles. For a conjugation quandle $Q={\\rm Conj}(G)$ of a group $G$ we\ndetermine several subgroups of ${\\rm Aut}(Q)$ and find necessary and sufficient\nconditions when these subgroups coincide with the whole group ${\\rm Aut}(Q)$.\nIn particular, we prove that ${\\rm Aut}({\\rm Conj}(G))={\\rm Z}(G)\\rtimes {\\rm\nAut}(G)$ if and only if either ${\\rm Z}(G)=1$ or $G$ is one of the groups\n$\\mathbb{Z}_2$, $\\mathbb{Z}_2^2$ or $\\mathbb{Z}_3$. For a big list of Takasaki\nquandles $T(G)$ of an abelian group $G$ with $2$-torsion we prove that the\ngroup of inner automorphisms ${\\rm Inn}(T(G))$ is a Coxeter group. We study\nautomorphisms of certain extensions of quandles and determine some interesting\nsubgroups of the automorphism groups of these quandles. Also we classify finite\nquandles $Q$ with $3\\leq k$-transitive action of ${\\rm Aut}(Q)$.\n",
"title": "Automorphism groups of quandles and related groups"
}
| null | null | null | null | true | null |
9067
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we introduce a new form of amortized variational inference by\nusing the forward KL divergence in a joint-contrastive variational loss. The\nresulting forward amortized variational inference is a likelihood-free method\nas its gradient can be sampled without bias and without requiring any\nevaluation of either the model joint distribution or its derivatives. We prove\nthat our new variational loss is optimized by the exact posterior marginals in\nthe fully factorized mean-field approximation, a property that is not shared\nwith the more conventional reverse KL inference. Furthermore, we show that\nforward amortized inference can be easily marginalized over large families of\nlatent variables in order to obtain a marginalized variational posterior. We\nconsider two examples of variational marginalization. In our first example we\ntrain a Bayesian forecaster for predicting a simplified chaotic model of\natmospheric convection. In the second example we train an amortized variational\napproximation of a Bayesian optimal classifier by marginalizing over the model\nspace. The result is a powerful meta-classification network that can solve\narbitrary classification problems without further training.\n",
"title": "Forward Amortized Inference for Likelihood-Free Variational Marginalization"
}
| null | null | null | null | true | null |
9068
| null |
Default
| null | null |
null |
{
"abstract": " The latest results of benchmarking research are presented for a variety of\nbeyond-CMOS charge- and spin-based devices. In addition to improving the\ndevice-level models, several new device proposals and a few majorly modified\ndevices are investigated. Deep pipelining circuits are employed to boost the\nthroughput of low-power devices. Furthermore, the benchmarking methodology is\nextended to interconnect-centric analyses and non-Boolean logic applications.\nIn contrast to Boolean circuits, non-Boolean circuits based on the cellular\nneural network demonstrate that spintronic devices can potentially outperform\nconventional CMOS devices.\n",
"title": "Beyond-CMOS Device Benchmarking for Boolean and Non-Boolean Logic Applications"
}
| null | null | null | null | true | null |
9069
| null |
Default
| null | null |
null |
{
"abstract": " I argue that some important elements of the current cosmological model are\n\"conventionalist\" in the sense defined by Karl Popper. These elements include\ndark matter and dark energy; both are auxiliary hypotheses that were invoked in\nresponse to observations that falsified the standard model as it existed at the\ntime. The use of conventionalist stratagems in response to unexpected\nobservations implies that the field of cosmology is in a state of \"degenerating\nproblemshift\" in the language of Imre Lakatos. I show that the \"concordance\"\nargument, often put forward by cosmologists in support of the current paradigm,\nis weaker than the convergence arguments that were made in the past in support\nof the atomic theory of matter or the quantization of energy.\n",
"title": "Cosmology and Convention"
}
| null | null | null | null | true | null |
9070
| null |
Default
| null | null |
null |
{
"abstract": " Standard clustering algorithms usually find regular-structured clusters such\nas ellipsoidally- or spherically-dispersed groups, but are more challenged with\ngroups lacking formal structure or definition. Syncytial clustering is the name\nthat we introduce for methods that merge groups obtained from standard\nclustering algorithms in order to reveal complex group structure in the data.\nHere, we develop a distribution-free fully-automated syncytial clustering\nalgorithm that can be used with $k$-means and other algorithms. Our approach\ncomputes the cumulative distribution function of the normed residuals from an\nappropriately fit $k$-groups model and calculates the nonparametric overlap\nbetween each pair of groups. Groups with high pairwise overlaps are merged as\nlong as the generalized overlap decreases. Our methodology is always a top\nperformer in identifying groups with regular and irregular structures in\nseveral datasets. The approach is also used to identify the distinct kinds of\ngamma ray bursts in the Burst and Transient Source Experiment 4Br catalog and\nalso the distinct kinds of activation in a functional Magnetic Resonance\nImaging study.\n",
"title": "Kernel-estimated Nonparametric Overlap-Based Syncytial Clustering"
}
| null | null | null | null | true | null |
9071
| null |
Default
| null | null |
null |
{
"abstract": " Exploration is a difficult challenge in reinforcement learning and even\nrecent state-of-the art curiosity-based methods rely on the simple\nepsilon-greedy strategy to generate novelty. We argue that pure random walks do\nnot succeed to properly expand the exploration area in most environments and\npropose to replace single random action choices by random goals selection\nfollowed by several steps in their direction. This approach is compatible with\nany curiosity-based exploration and off-policy reinforcement learning agents\nand generates longer and safer trajectories than individual random actions. To\nillustrate this, we present a task-independent agent that learns to reach\ncoordinates in screen frames and demonstrate its ability to explore with the\ngame Super Mario Bros. improving significantly the score of a baseline DQN\nagent.\n",
"title": "Goal-oriented Trajectories for Efficient Exploration"
}
| null | null | null | null | true | null |
9072
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we propose a stochastic optimization method that adaptively\ncontrols the sample size used in the computation of gradient approximations.\nUnlike other variance reduction techniques that either require additional\nstorage or the regular computation of full gradients, the proposed method\nreduces variance by increasing the sample size as needed. The decision to\nincrease the sample size is governed by an inner product test that ensures that\nsearch directions are descent directions with high probability. We show that\nthe inner product test improves upon the well known norm test, and can be used\nas a basis for an algorithm that is globally convergent on nonconvex functions\nand enjoys a global linear rate of convergence on strongly convex functions.\nNumerical experiments on logistic regression problems illustrate the\nperformance of the algorithm.\n",
"title": "Adaptive Sampling Strategies for Stochastic Optimization"
}
| null | null | null | null | true | null |
9073
| null |
Default
| null | null |
null |
{
"abstract": " There is a large literature on the asymptotic distribution of numbers free of\nlarge prime factors, so-called $\\textit{smooth}$ or $\\textit{friable}$ numbers.\nBut there is very little known about this distribution that is numerically\nexplicit. In this paper we follow the general plan for the saddle point\nargument of Hildebrand and Tenenbaum, giving explicit and fairly tight\nintervals in which the true count lies. We give two numerical examples of our\nmethod, and with the larger one, our interval is so tight we can exclude the\nfamous Dickman-de Bruijn asymptotic estimate as too small and the\nHildebrand-Tenenbaum main term as too large.\n",
"title": "Explicit estimates for the distribution of numbers free of large prime factors"
}
| null | null | null | null | true | null |
9074
| null |
Default
| null | null |
null |
{
"abstract": " We study the effects on $D$ of assuming that the power series ring $D[[X]]$\nis a $v$-domain or a PVMD. We show that a PVMD $D$ is completely integrally\nclosed if and only if $\\bigcap_{n=1}^{\\infty }(I^{n})_{v}=(0)$ for every proper\n$t$-invertible $t$-ideal $I$ of $D$. Using this, we show that if $D$ is an AGCD\ndomain, then $D[[X]]$ is integrally closed if and only if $D$ is a completely\nintegrally closed PVMD with torsion $t$-class group. We also determine several\nclasses of PVMDs for which being Archimedean is equivalent to being completely\nintegrally closed and give some new characterizations of integral domains\nrelated to Krull domains.\n",
"title": "Completely integrally closed Prufer $v$-multiplication domains"
}
| null | null |
[
"Mathematics"
] | null | true | null |
9075
| null |
Validated
| null | null |
null |
{
"abstract": " Autoregressive models are among the best performing neural density\nestimators. We describe an approach for increasing the flexibility of an\nautoregressive model, based on modelling the random numbers that the model uses\ninternally when generating data. By constructing a stack of autoregressive\nmodels, each modelling the random numbers of the next model in the stack, we\nobtain a type of normalizing flow suitable for density estimation, which we\ncall Masked Autoregressive Flow. This type of flow is closely related to\nInverse Autoregressive Flow and is a generalization of Real NVP. Masked\nAutoregressive Flow achieves state-of-the-art performance in a range of\ngeneral-purpose density estimation tasks.\n",
"title": "Masked Autoregressive Flow for Density Estimation"
}
| null | null | null | null | true | null |
9076
| null |
Default
| null | null |
null |
{
"abstract": " Due to their exceptional plasmonic properties, noble metals such as gold and\nsilver have been the materials of choice for the demonstration of various\nplasmonic and nanophotonic phenomena. However, noble metals' softness, lack of\ntailorability and low melting point along with challenges in thin film\nfabrication and device integration have prevented the realization of real-life\nplasmonic devices.In the recent years, titanium nitride (TiN) has emerged as a\npromising plasmonic material with good metallic and refractory (high\ntemperature stable) properties. The refractory nature of TiN could enable\npractical plasmonic devices operating at elevated temperatures for energy\nconversion and harsh-environment industries such as gas and oil. Here we report\non the temperature dependent dielectric functions of TiN thin films of varying\nthicknesses in the technologically relevant visible and near-infrared\nwavelength range from 330 nm to 2000 nm for temperatures up to 900 0C using\nin-situ high temperature ellipsometry. Our findings show that the complex\ndielectric function of TiN at elevated temperatures deviates from the optical\nparameters at room temperature, indicating degradation in plasmonic properties\nboth in the real and imaginary parts of the dielectric constant. However, quite\nstrikingly, the relative changes of the optical properties of TiN are\nsignificantly smaller compared to its noble metal counterparts. Using\nsimulations, we demonstrate that incorporating the temperature-induced\ndeviations into the numerical models leads to significant differences in the\noptical responses of high temperature nanophotonic systems. These studies hold\nthe key for accurate modeling of high temperature TiN based optical elements\nand nanophotonic systems for energy conversion, harsh-environment sensors and\nheat-assisted applications.\n",
"title": "Temperature-dependent optical properties of plasmonic titanium nitride thin films"
}
| null | null | null | null | true | null |
9077
| null |
Default
| null | null |
null |
{
"abstract": " We consider the well-studied partial sums problem in succint space where one\nis to maintain an array of n k-bit integers subject to updates such that\npartial sums queries can be efficiently answered. We present two succint\nversions of the Fenwick Tree - which is known for its simplicity and\npracticality. Our results hold in the encoding model where one is allowed to\nreuse the space from the input data. Our main result is the first that only\nrequires nk + o(n) bits of space while still supporting sum/update in O(log_b\nn) / O(b log_b n) time where 2 <= b <= log^O(1) n. The second result shows how\noptimal time for sum/update can be achieved while only slightly increasing the\nspace usage to nk + o(nk) bits. Beyond Fenwick Trees, the results are primarily\nbased on bit-packing and sampling - making them very practical - and they also\nallow for simple optimal parallelization.\n",
"title": "Succinct Partial Sums and Fenwick Trees"
}
| null | null | null | null | true | null |
9078
| null |
Default
| null | null |
null |
{
"abstract": " We propose approaches based on deep learning to localize objects in images\nwhen only a small training dataset is available and the images have low\nquality. That applies to many problems in medical image processing, and in\nparticular to the analysis of fluoroscopic (low-dose) X-ray images, where the\nimages have low contrast. We solve the problem by incorporating high-level\ninformation about the objects, which could be a simple geometrical model, like\na circular outline, or a more complex statistical model. A simple geometrical\nrepresentation can sufficiently describe some objects and only requires minimal\nlabeling. Statistical shape models can be used to represent more complex\nobjects. We propose computationally efficient two-stage approaches, which we\ncall deep morphing, for both representations by fitting the representation to\nthe output of a deep segmentation network.\n",
"title": "Deep Morphing: Detecting bone structures in fluoroscopic X-ray images with prior knowledge"
}
| null | null | null | null | true | null |
9079
| null |
Default
| null | null |
null |
{
"abstract": " In recent years there has been noticeable interest in the study of the \"shape\nof data\". Among the many ways a \"shape\" could be defined, topology is the most\ngeneral one, as it describes an object in terms of its connectivity structure:\nconnected components (topological features of dimension 0), cycles (features of\ndimension 1) and so on. There is a growing number of techniques, generally\ndenoted as Topological Data Analysis, aimed at estimating topological\ninvariants of a fixed object; when we allow this object to change, however,\nlittle has been done to investigate the evolution in its topology. In this work\nwe define the Persistence Flamelets, a multiscale version of one of the most\npopular tool in TDA, the Persistence Landscape. We examine its theoretical\nproperties and we show how it could be used to gain insights on KDEs bandwidth\nparameter.\n",
"title": "Persistence Flamelets: multiscale Persistent Homology for kernel density exploration"
}
| null | null | null | null | true | null |
9080
| null |
Default
| null | null |
null |
{
"abstract": " We propose a new approach to model ground penetrating radar signals that\npropagate through a homogeneous and isotropic medium, and are scattered at thin\nplanar fractures of arbitrary dip, azimuth, thickness and material filling. We\nuse analytical expressions for the Maxwell equations in a homogeneous space to\ndescribe the propagation of the signal in the rock matrix, and account for\nfrequency-dependent dispersion and attenuation through the empirical Jonscher\nformulation. We discretize fractures into elements that are linearly polarized\nby the incoming electric field that arrives from the source to each element,\nlocally, as a plane wave. To model the effective source wavelet we use a\ngeneralized Gamma distribution to define the antenna dipole moment. We combine\nmicroscopic and macroscopic Maxwell's equations to derive an analytic\nexpression for the response of each element, which describes the full electric\ndipole radiation patterns along with effective reflection coefficients of thin\nlayers. Our results compare favorably with finite-difference time-domain\nmodeling in the case of constant electrical parameters of the rock-matrix and\nfracture filling. Compared with traditional finite-difference time-domain\nmodeling, the proposed approach is faster and more flexible in terms of\nfracture orientations. A comparison with published laboratory results suggests\nthat the modeling approach can reproduce the main characteristics of the\nreflected wavelet.\n",
"title": "Effective modeling of ground penetrating radar in fractured media using analytic solutions for propagation, thin-bed interaction and dipolar scattering"
}
| null | null | null | null | true | null |
9081
| null |
Default
| null | null |
null |
{
"abstract": " Glass corrosion is a crucial problem in keeping and conservation of beadworks\nin museums. All kinds of glass beads undergo deterioration but blue-green\nlead-potassium glass beads of the 19th century are subjected to the destruction\nto the greatest extent. Blue-green lead-potassium glass beads of the 19th\ncentury obtained from exhibits kept in Russian museums were studied with the\npurpose to determine the causes of the observed phenomenon. For the comparison,\nyellow lead beads of the 19th century were also explored. Both kinds of beads\ncontain Sb but yellow ones are stable. Using scanning electron microscopy,\nenergy dispersive X-ray microspectrometry, electron backscatter diffraction,\ntransmission electron microscopy and X-ray powder analysis, we have registered\nthe presence of crystallites of orthorhombic KSbOSiO$_4$ and cubic\nPb$_2$Sb$_{1.5}$Fe$_{0.5}$O$_{6.5}$ in glass matrix of blue-green and yellow\nbeads, respectively. Both compounds form at rather high temperatures obviously\nduring glass melting and/or melt cooling. We suppose that the crystallites\ngenerate internal tensile strain in glass during its cooling which causes\nformation of multiple microcracks in inner domains of blue-green beads. We\nsuggest that the deterioration degree depends on quantity of the precipitates,\ntheir sizes and their temperature coefficients of linear expansion. In\nblue-green beads, the crystallites are distributed in their sizes from\n$\\sim\\,$200 nm to several tens of $\\mu$m and tend to gather in large colonies.\nThe sizes of crystallites in yellow beads are several hundreds of nm and their\nclusters contain few crystallites. This explains the difference in corrosion of\nthese kinds of beads containing crystals of Sb compounds.\n",
"title": "Crystallites in Color Glass Beads of the 19th Century and Their Influence on Fatal Deterioration of Glass"
}
| null | null | null | null | true | null |
9082
| null |
Default
| null | null |
null |
{
"abstract": " [Abridged] The infrared ro-vibrational emission lines from organic molecules\nin the inner regions of protoplanetary disks are unique probes of the physical\nand chemical structure of planet forming regions and the processes that shape\nthem. The non-LTE excitation effects of carbon dioxide (CO2) are studied in a\nfull disk model to evaluate: (i) what the emitting regions of the different CO2\nro-vibrational bands are; (ii) how the CO2 abundance can be best traced using\nCO2 ro-vibrational lines using future JWST data and; (iii) what the excitation\nand abundances tell us about the inner disk physics and chemistry. CO2 is a\nmajor ice component and its abundance can potentially test models with\nmigrating icy pebbles across the iceline. A full non-LTE CO2 excitation model\nhas been built. The characteristics of the model are tested using non-LTE slab\nmodels. Subsequently the CO2 line formation has been modelled using a\ntwo-dimensional disk model representative of T-Tauri disks. The CO2 gas that\nemits in the 15 $\\mu$m and 4.5 $\\mu$m regions of the spectrum is not in LTE and\narises in the upper layers of disks, pumped by infrared radiation. The v$_2$ 15\n$\\mu$m feature is dominated by optically thick emission for most of the models\nthat fit the observations and increases linearly with source luminosity. Its\nnarrowness compared with that of other molecules stems from a combination of\nthe low rotational excitation temperature (~250 K) and the inherently narrower\nfeature for CO2. The inferred CO2 abundances derived for observed disks are\nmore than two orders of magnitude lower than those in interstellar ices\n(~10$^5$), similar to earlier LTE disk estimates. Line-to-continuum ratios are\nlow, of order a few %, thus high signal-to-noise (S/N > 300) observations are\nneeded for individual line detections. Prospects of accurate abundance\nretreival with JWST-MIRI and JWST-NIRSpec are discussed.\n",
"title": "CO2 infrared emission as a diagnostic of planet-forming regions of disks"
}
| null | null | null | null | true | null |
9083
| null |
Default
| null | null |
null |
{
"abstract": " Elections seem simple---aren't they just counting? But they have a unique,\nchallenging combination of security and privacy requirements. The stakes are\nhigh; the context is adversarial; the electorate needs to be convinced that the\nresults are correct; and the secrecy of the ballot must be ensured. And they\nhave practical constraints: time is of the essence, and voting systems need to\nbe affordable and maintainable, and usable by voters, election officials, and\npollworkers. It is thus not surprising that voting is a rich research area\nspanning theory, applied cryptography, practical systems analysis, usable\nsecurity, and statistics. Election integrity involves two key concepts:\nconvincing evidence that outcomes are correct and privacy, which amounts to\nconvincing assurance that there is no evidence about how any given person\nvoted. These are obviously in tension. We examine how current systems walk this\ntightrope.\n",
"title": "Public Evidence from Secret Ballots"
}
| null | null | null | null | true | null |
9084
| null |
Default
| null | null |
null |
{
"abstract": " Observations of stars in the the solar vicinity show a clear tendency for old\nstars to have larger velocity dispersions. This relation is called the\nage-velocity dispersion relation (AVR) and it is believed to provide insight\ninto the heating history of the Milky Way galaxy. Here, in order to investigate\nthe origin of the AVR, we performed smoothed particle hydrodynamic simulations\nof the self-gravitating multiphase gas disks in the static disk-halo\npotentials. Star formation from cold and dense gas is taken into account, and\nwe analyze the evolution of these star particles. We find that exponents of\nsimulated AVR and the ratio of the radial to vertical velocity dispersion are\nclose to the observed values. We also find that the simulated AVR is not a\nsimple consequence of dynamical heating. The evolution tracks of stars with\ndifferent epochs evolve gradually in the age-velocity dispersion plane as a\nresult of: (1) the decrease in velocity dispersion in star forming regions, and\n(2) the decrease in the number of cold/dense/gas as scattering sources. These\nresults suggest that the AVR involves not only the heating history of a stellar\ndisk, but also the historical evolution of the ISM in a galaxy.\n",
"title": "Imprints of Zero-Age Velocity Dispersions and Dynamical Heating on the Age-Velocity dispersion Relation"
}
| null | null |
[
"Physics"
] | null | true | null |
9085
| null |
Validated
| null | null |
null |
{
"abstract": " Random column sampling is not guaranteed to yield data sketches that preserve\nthe underlying structures of the data and may not sample sufficiently from\nless-populated data clusters. Also, adaptive sampling can often provide\naccurate low rank approximations, yet may fall short of producing descriptive\ndata sketches, especially when the cluster centers are linearly dependent.\nMotivated by that, this paper introduces a novel randomized column sampling\ntool dubbed Spatial Random Sampling (SRS), in which data points are sampled\nbased on their proximity to randomly sampled points on the unit sphere. The\nmost compelling feature of SRS is that the corresponding probability of\nsampling from a given data cluster is proportional to the surface area the\ncluster occupies on the unit sphere, independently from the size of the cluster\npopulation. Although it is fully randomized, SRS is shown to provide\ndescriptive and balanced data representations. The proposed idea addresses a\npressing need in data science and holds potential to inspire many novel\napproaches for analysis of big data.\n",
"title": "Spatial Random Sampling: A Structure-Preserving Data Sketching Tool"
}
| null | null | null | null | true | null |
9086
| null |
Default
| null | null |
null |
{
"abstract": " Recently, dinitriles (NC(CH2)nCN) and especially adiponitrile (ADN, n=4) have\nattracted the attention as secure electrolyte solvents due to their chemical\nstability, high boiling points, high flash points and low vapor pressure. The\ngood solvating properties of ADN toward lithium salts and its high\nelectrochemical stability (~ 6V vs. Li/Li+) make it suitable for safer Li-ions\ncells without performances loss. In this study, ADN is used as a single\nelectrolyte solvent with lithium bis(trimethylsulfonyl)imide (LiTFSI). This\nelectrolyte allows the use of aluminum collectors as almost no corrosion occurs\nat voltages up to 4.2 V. Physico-chemical properties of ADN-LiTFSI electrolyte\nsuch as salt dissolution, conductivity and viscosity were determined. The\ncycling performances of batteries using Li4Ti5O12 (LTO) as anode and\nLiNi1/3Co1/3Mn1/3O2 (NMC) as cathode were determined. The results indicate that\nLTO/NMC batteries exhibit excellent rate capabilities with a columbic\nefficiency close to 100%. As an example, cells were able to reach a capacity of\n165 mAh.g-1 at 0.1C and a capacity retention of more than 98% after 200 cycles\nat 0.5C. In addition, electrodes analyses by SEM, XPS and electrochemical\nimpedance spectroscopy after cycling confirming minimal surface changes of the\nelectrodes in the studied battery system\n",
"title": "Adiponitrile-LiTFSI solution as alkylcarbonate free electrolyte for LTO/NMC Li-ion batteries"
}
| null | null | null | null | true | null |
9087
| null |
Default
| null | null |
null |
{
"abstract": " Practical solutions to bootstrap security in today's information and\ncommunication systems critically depend on centralized services for\nauthentication as well as key and trust management. This is particularly true\nfor mobile users. Identity providers such as Google or Facebook have active\nuser bases of two billion each, and the subscriber number of mobile operators\nexceeds five billion unique users as of early 2018. If these centralized\nservices go completely `dark' due to natural or man made disasters, large scale\nblackouts, or country-wide censorship, the users are left without practical\nsolutions to bootstrap security on their mobile devices. Existing distributed\nsolutions, for instance, the so-called web-of-trust are not sufficiently\nlightweight. Furthermore, they support neither cross-application on mobile\ndevices nor strong protection of key material using hardware security modules.\nWe propose Sea of Lights(SoL), a practical lightweight scheme for bootstrapping\ndevice-to-device security wirelessly, thus, enabling secure distributed\nself-organized networks. It is tailored to operate `in the dark' and provides\nstrong protection of key material as well as an intuitive means to build a\nlightweight web-of-trust. SoL is particularly well suited for local or urban\noperation in scenarios such as the coordination of emergency response, where it\nhelps containing/limiting the spreading of misinformation. As a proof of\nconcept, we implement SoL in the Android platform and hence test its\nfeasibility on real mobile devices. We further evaluate its key performance\naspects using simulation.\n",
"title": "Sea of Lights: Practical Device-to-Device Security Bootstrapping in the Dark"
}
| null | null | null | null | true | null |
9088
| null |
Default
| null | null |
null |
{
"abstract": " Proposed the computerized method for calculating the relative level of order\ncomposites. Correlation between a level of structure order and properties of\nsolids is shown. Discussed the possibility of clarifying the terminology used\nin describing the structure.\n",
"title": "On the correlation between a level of structure order and properties of composites. In Memory of Yu.L. Klimontovich"
}
| null | null | null | null | true | null |
9089
| null |
Default
| null | null |
null |
{
"abstract": " It was discovered that there is a formal analogy between Nevanlinna theory\nand Diophantine approximation. Via Vojta's dictionary, the Second Main Theorem\nin Nevanlinna theory corresponds to Schmidt's Subspace Theorem in Diophantine\napproximation. Recently, Cherry, Dethloff, and Tan (arXiv:1503.08801v2\n[math.CV]) obtained a Second Main Theorem for moving hypersurfaces intersecting\nprojective varieites. In this paper, we shall give the counterpart of their\nSecond Main Theorem in Diophantine approximation.\n",
"title": "Schmidt's subspace theorem for moving hypersurface targets"
}
| null | null | null | null | true | null |
9090
| null |
Default
| null | null |
null |
{
"abstract": " Unlike the conventional first-order network (FoN), the higher-order network\n(HoN) provides a more accurate description of transitions by creating\nadditional nodes to encode higher-order dependencies. However, there exists no\nvisualization and exploration tool for the HoN. For applications such as the\ndevelopment of strategies to control species invasion through global shipping\nwhich is known to exhibit higher-order dependencies, the existing FoN\nvisualization tools are limited. In this paper, we present HoNVis, a novel\nvisual analytics framework for exploring higher-order dependencies of the\nglobal ocean shipping network. Our framework leverages coordinated multiple\nviews to reveal the network structure at three levels of detail (i.e., the\nglobal, local, and individual port levels). Users can quickly identify ports of\ninterest at the global level and specify a port to investigate its higher-order\nnodes at the individual port level. Investigating a larger-scale impact is\nenabled through the exploration of HoN at the local level. Using the global\nocean shipping network data, we demonstrate the effectiveness of our approach\nwith a real-world use case conducted by domain experts specializing in species\ninvasion. Finally, we discuss the generalizability of this framework to other\nreal-world applications such as information diffusion in social networks and\nepidemic spreading through air transportation.\n",
"title": "HoNVis: Visualizing and Exploring Higher-Order Networks"
}
| null | null | null | null | true | null |
9091
| null |
Default
| null | null |
null |
{
"abstract": " The dissolution of porous media in a geologic formation induced by the\ninjection of massive amounts of CO2 can undermine the mechanical stability of\nthe formation structure before carbon mineralization takes place. The\ngeomechanical impact of geologic carbon storage is therefore closely related to\nthe structural sustainability of the chosen reservoir as well as the\nprobability of buoyancy driven CO2 leakage through caprocks. Here we show, with\na combination of ex situ nanotomography and in situ microtomography, that the\npresence of dissolved CO2 in water produces a homogeneous dissolution pattern\nin natural chalk microstructure. This pattern stems from a greater apparent\nsolubility of chalk and therefore a greater reactive subvolume in a sample.\nWhen a porous medium dissolves homogeneously in an imposed flow field, three\ngeomechanical effects were observed: material compaction, fracturing and grain\nrelocation. These phenomena demonstrated distinct feedbacks to the migration of\nthe dissolution front and severely complicated the infiltration instability\nproblem. We conclude that the presence of dissolved CO2 makes the dissolution\nfront less susceptible to spatial and temporal perturbations in the strongly\ncoupled geochemical and geomechanical processes.\n",
"title": "Direct observation of coupled geochemical and geomechanical impacts on chalk microstructural evolution under elevated CO2 pressure. Part I"
}
| null | null |
[
"Physics"
] | null | true | null |
9092
| null |
Validated
| null | null |
null |
{
"abstract": " In this paper, we study the algebraic symplectic geometry of the singular\nmoduli spaces of Higgs bundles of degree $0$ and rank $n$ on a compact Riemann\nsurface $X$ of genus $g$. In particular, we prove that such moduli spaces are\nsymplectic singularities, in the sense of Beauville [Bea00], and admit a\nprojective symplectic resolution if and only if $g=1$ or $(g, n)=(2,2)$. These\nresults are an application of a recent paper by Bellamy and Schedler [BS16] via\nthe so-called Isosingularity Theorem.\n",
"title": "Symplectic resolutions for Higgs moduli spaces"
}
| null | null | null | null | true | null |
9093
| null |
Default
| null | null |
null |
{
"abstract": " Some properties of defect modes of cholesteric liquid crystals (CLC) are\npresented. It is shown that when the CLC layer is thin the density of states\nand emission intensity are maximum for the defect mode, whereas when the CLC\nlayer is thick, these peaks are observed at the edges of the photonic band gap.\nSimilarly, when the gain is low, the density of states and emission intensity\nare maximum for the defect mode, whereas at high gains these peaks are also\nobserved at the edges of the photonic band gap. The possibilities of\nlow-threshold lasing and obtaining high-Q microcavities have been investigated.\n",
"title": "Investigation of Defect Modes of Chiral Photonic Crystals"
}
| null | null | null | null | true | null |
9094
| null |
Default
| null | null |
null |
{
"abstract": " It is reported on growth of mm-sized single-crystals of the low-dimensional S\n= 1/2 spin compound Cu6(Ge,Si)6O18.6H2O by a diffusion technique in aqueous\nsolution. A route to form Si-rich crystals down to possibly dioptase, the pure\nsilicate, is discussed. Further, the assignment of dd excitations from UV-VIS\nspectra of the hexahydrate and the fully dehydrated compound is proposed in\ncomparison to dioptase and selected Cu(II) oxo-compounds using bond strength\nconsiderations. Non-doped cuprates as layer compounds show higher excitation\nenergies than the title compound. However, when the antiferromagnetic\ninteraction energy as Jzln(2) is taken into account for cuprates, a single\nlinear relationship between the Dqe excitation energy and equatorial Cu(II)-O\nbond strength is confirmed for all compounds. A linear representation is also\nconfirmed between 2A1g energies and a function of axial and equatorial Cu-O\nbond distances, when auxiliary axial bonds are used for four-coordinated\ncompounds. The quotient Dt/Ds of experimental orbital energies deviating from\nthe general trend to smaller values indicates the existence of H2O respectively\nCl1- axial ligands in comparison to oxo-ligands, whereas larger Dt/Dqe values\nindicate missing axial bonds. The quotient of the excitation energy 2A1g by\n2x2Eg-2B2g allows to check for correctness of the assignment and to distinguish\nbetween axial oxo-ligands and others like H2O or Cl1-. Some assignments\npreviously reported were corrected.\n",
"title": "Crystal Growth of Cu6(Ge,Si)6O18.6H2O and Assignment of UV-VIS Spectra in Comparison to Dehydrated Dioptase and Selected Cu(II) Oxo-Compounds Including Cuprates"
}
| null | null | null | null | true | null |
9095
| null |
Default
| null | null |
null |
{
"abstract": " Controlling and confining light by exciting plasmons in resonant metallic\nnanostructures is an essential aspect of many new emerging optical\ntechnologies. Here we explore the possibility of controllably reconfiguring the\nintrinsic optical properties of semi-continuous gold films, by inducing\npermanent morphological changes with a femtosecond (fs)-pulsed laser above a\ncritical power. Optical transmission spectroscopy measurements show a\ncorrelation between the spectra of the morphologically modified films and the\nwavelength, polarization, and the intensity of the laser used for alteration.\nIn order to understand the modifications induced by the laser writing, we\nexplore the near-field properties of these films with electron energy-loss\nspectroscopy (EELS). A comparison between our experimental data and full-wave\nsimulations on the exact film morphologies hints toward a restructuring of the\nintrinsic plasmonic eigenmodes of the metallic film by photothermal effects. We\nexplain these optical changes with a simple model and demonstrate\nexperimentally that laser writing can be used to controllably modify the\noptical properties of these semi-continuous films. These metal films offer an\neasy-to-fabricate and scalable platform for technological applications such as\nmolecular sensing and ultra-dense data storage.\n",
"title": "Optical reconfiguration and polarization control in semi-continuous gold films close to the percolation threshold"
}
| null | null | null | null | true | null |
9096
| null |
Default
| null | null |
null |
{
"abstract": " Codes over Galois rings have been studied extensively during the last three\ndecades. Negacyclic codes over $GR(2^a,m)$ of length $2^s$ have been\ncharacterized: the ring $\\mathcal{R}_2(a,m,-1)= \\frac{GR(2^a,m)[x]}{\\langle\nx^{2^s}+1\\rangle}$ is a chain ring. Furthermore, these results have been\ngeneralized to $\\lambda$-constacyclic codes for any unit $\\lambda$ of the form\n$4z-1$, $z\\in GR(2^a, m)$. In this paper, we study more general cases and\ninvestigate all cases where $\\mathcal{R}_p(a,m,\\gamma)=\n\\frac{GR(p^a,m)[x]}{\\langle x^{p^s}-\\gamma \\rangle}$ is a chain ring. In\nparticular, necessary and sufficient conditions for the ring\n$\\mathcal{R}_p(a,m,\\gamma)$ to be a chain ring are obtained. In addition, by\nusing this structure we investigate all $\\gamma$-constacyclic codes over\n$GR(p^a,m)$ when $\\mathcal{R}_p(a,m,\\gamma)$ is a chain ring. Necessary and\nsufficient conditions for the existence of self-orthogonal and self-dual\n$\\gamma$-constacyclic codes are also provided. Among others, for any prime $p$,\nthe structure of $\\mathcal{R}_p(a,m,\\gamma)=\\frac{GR(p^a,m)[x]}{\\langle\nx^{p^s}-\\gamma\\rangle}$ is used to establish the Hamming and homogeneous\ndistances of $\\gamma$-constacyclic codes.\n",
"title": "Some Repeated-Root Constacyclic Codes over Galois Rings"
}
| null | null | null | null | true | null |
9097
| null |
Default
| null | null |
null |
{
"abstract": " We prove a version of Onsager's conjecture on the conservation of energy for\nthe incompressible Euler equations in the context of statistical solutions, as\nintroduced recently by Fjordholm et al. As a byproduct, we also obtain a new\nproof for the conservative direction of Onsager's conjecture for weak\nsolutions. Dedicated to Edriss S. Titi on the occasion of his 60th birthday.\n",
"title": "Statistical solutions and Onsager's conjecture"
}
| null | null | null | null | true | null |
9098
| null |
Default
| null | null |
null |
{
"abstract": " Geometric Brownian motion (GBM) is a key model for representing\nself-reproducing entities. Self-reproduction may be considered the definition\nof life [5], and the dynamics it induces are of interest to those concerned\nwith living systems from biology to economics. Trajectories of GBM are\ndistributed according to the well-known log-normal density, broadening with\ntime. However, in many applications, what's of interest is not a single\ntrajectory but the sum, or average, of several trajectories. The distribution\nof these objects is more complicated. Here we show two different ways of\nfinding their typical trajectories. We make use of an intriguing connection to\nspin glasses: the expected free energy of the random energy model is an average\nof log-normal variates. We make the mapping to GBM explicit and find that the\nfree energy result gives qualitatively correct behavior for GBM trajectories.\nWe then also compute the typical sum of lognormal variates using Ito calculus.\nThis alternative route is in close quantitative agreement with numerical work.\n",
"title": "The sum of log-normal variates in geometric Brownian motion"
}
| null | null | null | null | true | null |
9099
| null |
Default
| null | null |
null |
{
"abstract": " To identify emerging microscopic structures in low temperature spin glasses,\nwe study self-sustained clusters (SSC) in spin models defined on sparse random\ngraphs. A message-passing algorithm is developed to determine the probability\nof individual spins to belong to SSC. Results for specific instances, which\ncompare the predicted SSC associations with the dynamical properties of spins\nobtained from numerical simulations, show that SSC association identifies\nindividual slow-evolving spins. This insight gives rise to a powerful approach\nfor predicting individual spin dynamics from a single snapshot of an\nequilibrium spin configuration, namely from limited static information, which\ncan be used to devise generic prediction tools applicable to a wide range of\nareas.\n",
"title": "Slow Spin Dynamics and Self-Sustained Clusters in Sparsely Connected Systems"
}
| null | null | null | null | true | null |
9100
| null |
Default
| null | null |
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