text
null | inputs
dict | prediction
null | prediction_agent
null | annotation
list | annotation_agent
null | multi_label
bool 1
class | explanation
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{
"abstract": " This paper investigates the achievable rates of an additive white Gaussian\nnoise (AWGN) energy-harvesting (EH) channel with an infinite battery. The EH\nprocess is characterized by a sequence of blocks of harvested energy, which is\nknown causally at the source. The harvested energy remains constant within a\nblock while the harvested energy across different blocks is characterized by a\nsequence of independent and identically distributed (i.i.d.) random variables.\nThe blocks have length $L$, which can be interpreted as the coherence time of\nthe energy arrival process. If $L$ is a constant or grows sublinearly in the\nblocklength $n$, we fully characterize the first-order term in the asymptotic\nexpansion of the maximum transmission rate subject to a fixed tolerable error\nprobability $\\varepsilon$. The first-order term is known as the\n$\\varepsilon$-capacity. In addition, we obtain lower and upper bounds on the\nsecond-order term in the asymptotic expansion, which reveal that the second\norder term scales as $\\sqrt{\\frac{L}{n}}$ for any $\\varepsilon$ less than\n$1/2$. The lower bound is obtained through analyzing the save-and-transmit\nstrategy. If $L$ grows linearly in $n$, we obtain lower and upper bounds on the\n$\\varepsilon$-capacity, which coincide whenever the cumulative distribution\nfunction (cdf) of the EH random variable is continuous and strictly increasing.\nIn order to achieve the lower bound, we have proposed a novel adaptive\nsave-and-transmit strategy, which chooses different save-and-transmit codes\nacross different blocks according to the energy variation across the blocks.\n",
"title": "On Achievable Rates of AWGN Energy-Harvesting Channels with Block Energy Arrival and Non-Vanishing Error Probabilities"
}
| null | null | null | null | true | null |
15701
| null |
Default
| null | null |
null |
{
"abstract": " We consider the problem of probabilistic projection of the total fertility\nrate (TFR) for subnational regions. We seek a method that is consistent with\nthe UN's recently adopted Bayesian method for probabilistic TFR projections for\nall countries, and works well for all countries. We assess various possible\nmethods using subnational TFR data for 47 countries. We find that the method\nthat performs best in terms of out-of-sample predictive performance and also in\nterms of reproducing the within-country correlation in TFR is a method that\nscales the national trajectory by a region-specific scale factor that is\nallowed to vary slowly over time. This supports the hypothesis of Watkins\n(1990, 1991) that within-country TFR converges over time in response to\ncountry-specific factors, and extends the Watkins hypothesis to the last 50\nyears and to a much wider range of countries around the world.\n",
"title": "Probabilistic Projection of Subnational Total Fertility Rates"
}
| null | null |
[
"Statistics"
] | null | true | null |
15702
| null |
Validated
| null | null |
null |
{
"abstract": " Persistent homology typically studies the evolution of homology groups\n$H_p(X)$ (with coefficients in a field) along a filtration of topological\nspaces. $A_\\infty$-persistence extends this theory by analysing the evolution\nof subspaces such as $V := \\text{Ker}\\, {\\Delta_n}_{| H_p(X)} \\subseteq\nH_p(X)$, where $\\{\\Delta_m\\}_{m\\geq1}$ denotes a structure of\n$A_\\infty$-coalgebra on $H_*(X)$. In this paper we illustrate how\n$A_\\infty$-persistence can be useful beyond persistent homology by discussing\nthe topological meaning of $V$, which is the most basic form of\n$A_\\infty$-persistence group. In addition, we explore how to choose\n$A_\\infty$-coalgebras along a filtration to make the $A_\\infty$-persistence\ngroups carry more faithful information.\n",
"title": "Optimising the topological information of the $A_\\infty$-persistence groups"
}
| null | null | null | null | true | null |
15703
| null |
Default
| null | null |
null |
{
"abstract": " Using focused electron-beam-induced deposition (FEBID), we fabricate\nvertical, platinum-coated cobalt nanowires with a controlled three-dimensional\nstructure. The latter is engineered to feature bends along the height: these\nare used as pinning sites for domain walls, the presence of which we\ninvestigate using X-ray Magnetic Circular Dichroism (XMCD) coupled to\nPhotoEmission Electron Microscopy (PEEM). The vertical geometry of our sample\ncombined with the low incidence of the X-ray beam produce an extended wire\nshadow which we use to recover the wire's magnetic configuration. In this\ntransmission configuration, the whole sample volume is probed, thus\ncircumventing the limitation of PEEM to surfaces. This article reports on the\nfirst study of magnetic nanostructures standing perpendicular to the substrate\nwith XMCD-PEEM. The use of this technique in shadow mode enabled us to confirm\nthe presence of a domain wall (DW) without direct imaging of the nanowire.\n",
"title": "Transmission XMCD-PEEM imaging of an engineered vertical FEBID cobalt nanowire with a domain wall"
}
| null | null | null | null | true | null |
15704
| null |
Default
| null | null |
null |
{
"abstract": " Developing efficient numerical algorithms for the solution of high\ndimensional random Partial Differential Equations (PDEs) has been a challenging\ntask due to the well-known curse of dimensionality. We present a new solution\nframework for these problems based on a deep learning approach. Specifically,\nthe random PDE is approximated by a feed-forward fully-connected deep residual\nnetwork, with either strong or weak enforcement of initial and boundary\nconstraints. The framework is mesh-free, and can handle irregular computational\ndomains. Parameters of the approximating deep neural network are determined\niteratively using variants of the Stochastic Gradient Descent (SGD) algorithm.\nThe satisfactory accuracy of the proposed frameworks is numerically\ndemonstrated on diffusion and heat conduction problems, in comparison with the\nconverged Monte Carlo-based finite element results.\n",
"title": "A Deep Neural Network Surrogate for High-Dimensional Random Partial Differential Equations"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
15705
| null |
Validated
| null | null |
null |
{
"abstract": " We study optical forces acting upon semiconductor quantum dots and the force\ndriven motion of the dots in a colloid. In the spectral range of exciton\ntransitions in uantum dots, when the photon energy is close to the exciton\nenergy, the polarizability of the dots is drastically increased. It leads to a\nresonant increase of both the gradient and the scattering contributions to the\noptical force, which enables the efficient manipulation with the dots. We\nreveal that the optical grating of the colloid leads to the formation of a\nfluid photonic crystal with spatially periodic circulating fluxes and density\nof the dots. Pronounced resonant dielectric response of semiconductor quantum\ndots enables a separation of the quantum dots with different exciton\nfrequencies.\n",
"title": "Fluid photonic crystal from colloidal quantum dots"
}
| null | null |
[
"Physics"
] | null | true | null |
15706
| null |
Validated
| null | null |
null |
{
"abstract": " Inter-subject variability between individuals poses a challenge in\ninter-subject brain signal analysis problems. A new algorithm for\nsubject-selection based on clustering covariance matrices on a Riemannian\nmanifold is proposed. After unsupervised selection of the subsets of relevant\nsubjects, data in a cluster is mapped to a tangent space at the mean point of\ncovariance matrices in that cluster and an SVM classifier on labeled data from\nrelevant subjects is trained. Experiment on an EEG seizure database shows that\nthe proposed method increases the accuracy over state-of-the-art from 86.83% to\n89.84% and specificity from 87.38% to 89.64% while reducing the false positive\nrate/hour from 0.8/hour to 0.77/hour.\n",
"title": "Subject Selection on a Riemannian Manifold for Unsupervised Cross-subject Seizure Detection"
}
| null | null | null | null | true | null |
15707
| null |
Default
| null | null |
null |
{
"abstract": " Bell inequalities are usually derived by assuming locality and realism, and\ntherefore experimental violations of Bell inequalities are usually taken to\nimply violations of either locality or realism, or both. But, after reviewing\nan oversight by Bell, here we derive the Bell-CHSH inequality by assuming only\nthat Bob can measure along the directions b and b' simultaneously while Alice\nmeasures along either a or a', and likewise Alice can measure along the\ndirections a and a' simultaneously while Bob measures along either b or b',\nwithout assuming locality. The observed violations of the Bell-CHSH inequality\ntherefore simply verify the manifest impossibility of measuring along the\ndirections b and b' (or along the directions a and a') simultaneously, in any\nrealizable EPR-Bohm type experiment.\n",
"title": "On a Surprising Oversight by John S. Bell in the Proof of his Famous Theorem"
}
| null | null | null | null | true | null |
15708
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we find explicit formulas for higher order derivatives of the\ninverse tangent function. More precisely, we study polynomials which are\ninduced from the higher-order derivatives of arctan(x). Successively, we give\ngenerating functions, recurrence relations and some particular properties for\nthese polynomials. Connections to Chebyshev, Fibonacci, Lucas and Matching\npolynomials are established.\n",
"title": "On the higher derivatives of the inverse tangent function"
}
| null | null | null | null | true | null |
15709
| null |
Default
| null | null |
null |
{
"abstract": " e-ASTROGAM (enhanced ASTROGAM) is a breakthrough Observatory space mission,\nwith a detector composed by a Silicon tracker, a calorimeter, and an\nanticoincidence system, dedicated to the study of the non-thermal Universe in\nthe photon energy range from 0.3 MeV to 3 GeV - the lower energy limit can be\npushed to energies as low as 150 keV for the tracker, and to 30 keV for\ncalorimetric detection. The mission is based on an advanced space-proven\ndetector technology, with unprecedented sensitivity, angular and energy\nresolution, combined with polarimetric capability. Thanks to its performance in\nthe MeV-GeV domain, substantially improving its predecessors, e-ASTROGAM will\nopen a new window on the non-thermal Universe, making pioneering observations\nof the most powerful Galactic and extragalactic sources, elucidating the nature\nof their relativistic outflows and their effects on the surroundings. With a\nline sensitivity in the MeV energy range one to two orders of magnitude better\nthan previous generation instruments, e-ASTROGAM will determine the origin of\nkey isotopes fundamental for the understanding of supernova explosion and the\nchemical evolution of our Galaxy. The mission will provide unique data of\nsignificant interest to a broad astronomical community, complementary to\npowerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT,\nLSST, JWST, Athena, CTA, IceCube, KM3NeT, and LISA.\n",
"title": "Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)"
}
| null | null | null | null | true | null |
15710
| null |
Default
| null | null |
null |
{
"abstract": " We report magnetic and thermodynamic properties of a $4d^1$ (Mo$^{5+}$)\nmagnetic insulator MoOPO$_4$ single crystal, which realizes a $J_1$-$J_2$\nHeisenberg spin-$1/2$ model on a stacked square lattice. The specific-heat\nmeasurements show a magnetic transition at 16 K which is also confirmed by\nmagnetic susceptibility, ESR, and neutron diffraction measurements. Magnetic\nentropy deduced from the specific heat corresponds to a two-level degree of\nfreedom per Mo$^{5+}$ ion, and the effective moment from the susceptibility\ncorresponds to the spin-only value. Using {\\it ab initio} quantum chemistry\ncalculations we demonstrate that the Mo$^{5+}$ ion hosts a purely spin-$1/2$\nmagnetic moment, indicating negligible effects of spin-orbit interaction. The\nquenched orbital moments originate from the large displacement of Mo ions\ninside the MoO$_6$ octahedra along the apical direction. The ground state is\nshown by neutron diffraction to support a collinear Néel-type magnetic order,\nand a spin-flop transition is observed around an applied magnetic field of 3.5\nT. The magnetic phase diagram is reproduced by a mean-field calculation\nassuming a small easy-axis anisotropy in the exchange interactions. Our results\nsuggest $4d$ molybdates as an alternative playground to search for model\nquantum magnets.\n",
"title": "$J_1$-$J_2$ square lattice antiferromagnetism in the orbitally quenched insulator MoOPO$_4$"
}
| null | null | null | null | true | null |
15711
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we introduce the concept of Eventness for audio event\ndetection, which can, in part, be thought of as an analogue to Objectness from\ncomputer vision. The key observation behind the eventness concept is that audio\nevents reveal themselves as 2-dimensional time-frequency patterns with specific\ntextures and geometric structures in spectrograms. These time-frequency\npatterns can then be viewed analogously to objects occurring in natural images\n(with the exception that scaling and rotation invariance properties do not\napply). With this key observation in mind, we pose the problem of detecting\nmonophonic or polyphonic audio events as an equivalent visual object(s)\ndetection problem under partial occlusion and clutter in spectrograms. We adapt\na state-of-the-art visual object detection model to evaluate the audio event\ndetection task on publicly available datasets. The proposed network has\ncomparable results with a state-of-the-art baseline and is more robust on\nminority events. Provided large-scale datasets, we hope that our proposed\nconceptual model of eventness will be beneficial to the audio signal processing\ncommunity towards improving performance of audio event detection.\n",
"title": "Eventness: Object Detection on Spectrograms for Temporal Localization of Audio Events"
}
| null | null | null | null | true | null |
15712
| null |
Default
| null | null |
null |
{
"abstract": " This work proposes a new, online algorithm for estimating the local scale\ncorrection to apply to the output of a monocular SLAM system and obtain an as\nfaithful as possible metric reconstruction of the 3D map and of the camera\ntrajectory. Within a Bayesian framework, it integrates observations from a\ndeep-learning based generic object detector and a prior on the evolution of the\nscale drift. For each observation class, a predefined prior on the heights of\nthe class objects is used. This allows to define the observations likelihood.\nDue to the scale drift inherent to monocular SLAM systems, we integrate a rough\nmodel on the dynamics of scale drift. Quantitative evaluations of the system\nare presented on the KITTI dataset, and compared with different approaches. The\nresults show a superior performance of our proposal in terms of relative\ntranslational error when compared to other monocular systems.\n",
"title": "Bayesian Scale Estimation for Monocular SLAM Based on Generic Object Detection for Correcting Scale Drift"
}
| null | null | null | null | true | null |
15713
| null |
Default
| null | null |
null |
{
"abstract": " Given an orthogonal polygon $ P $ with $ n $ vertices, the goal of the\nwatchman route problem is finding a path $ S $ of the minimum length in $ P $\nsuch that every point of the polygon $ P $ is visible from at least one of the\npoint of $ S $. In the other words, in the watchman route problem we must\ncompute a shortest watchman route inside a simple polygon of $ n $ vertices\nsuch that all the points interior to the polygon and on its boundary are\nvisible to at least one point on the route. If route and polygon be orthogonal,\nit is called orthogonal watchman route problem. One of the targets of this\nproblem is finding the orthogonal path with the minimum number of bends as\npossible. We present a linear-time algorithm for the orthogonal watchman route\nproblem, in which the given polygon is monotone. Our algorithm can be used also\nfor the problem on simple orthogonal polygons $ P $ for which the dual graph\ninduced by the vertical decomposition of $ P $ is a path, which is called path\npolygon.\n",
"title": "A Linear-time Algorithm for Orthogonal Watchman Route Problem with Minimum Bends"
}
| null | null | null | null | true | null |
15714
| null |
Default
| null | null |
null |
{
"abstract": " A standard theorem in nonsmooth analysis states that a piecewise affine\nfunction $F:\\mathbb R^n\\rightarrow\\mathbb R^n$ is surjective if it is\ncoherently oriented in that the linear parts of its selection functions all\nhave the same nonzero determinant sign. In this note we prove that surjectivity\nalready follows from coherent orientation of the selection functions which are\nactive on the unbounded sets of a polyhedral subdivision of the domain\ncorresponding to $F$. A side bonus of the argumentation is a short proof of the\nclassical statement that an injective piecewise affine function is coherently\noriented.\n",
"title": "A note on surjectivity of piecewise affine mappings"
}
| null | null | null | null | true | null |
15715
| null |
Default
| null | null |
null |
{
"abstract": " We propose a class of intrinsic Gaussian processes (in-GPs) for\ninterpolation, regression and classification on manifolds with a primary focus\non complex constrained domains or irregular shaped spaces arising as subsets or\nsubmanifolds of R, R2, R3 and beyond. For example, in-GPs can accommodate\nspatial domains arising as complex subsets of Euclidean space. in-GPs respect\nthe potentially complex boundary or interior conditions as well as the\nintrinsic geometry of the spaces. The key novelty of the proposed approach is\nto utilise the relationship between heat kernels and the transition density of\nBrownian motion on manifolds for constructing and approximating valid and\ncomputationally feasible covariance kernels. This enables in-GPs to be\npractically applied in great generality, while existing approaches for\nsmoothing on constrained domains are limited to simple special cases. The broad\nutilities of the in-GP approach is illustrated through simulation studies and\ndata examples.\n",
"title": "Intrinsic Gaussian processes on complex constrained domains"
}
| null | null | null | null | true | null |
15716
| null |
Default
| null | null |
null |
{
"abstract": " Most existing approaches to co-existing communication/radar systems assume\nthat the radar and communication systems are coordinated, i.e., they share\ninformation, such as relative position, transmitted waveforms and channel\nstate. In this paper, we consider an un-coordinated scenario where a\ncommunication receiver is to operate in the presence of a number of radars, of\nwhich only a sub-set may be active, which poses the problem of estimating the\nactive waveforms and the relevant parameters thereof, so as to cancel them\nprior to demodulation. Two algorithms are proposed for such a joint waveform\nestimation/data demodulation problem, both exploiting sparsity of a proper\nrepresentation of the interference and of the vector containing the errors of\nthe data block, so as to implement an iterative joint interference removal/data\ndemodulation process. The former algorithm is based on classical on-grid\ncompressed sensing (CS), while the latter forces an atomic norm (AN)\nconstraint: in both cases the radar parameters and the communication\ndemodulation errors can be estimated by solving a convex problem. We also\npropose a way to improve the efficiency of the AN-based algorithm. The\nperformance of these algorithms are demonstrated through extensive simulations,\ntaking into account a variety of conditions concerning both the interferers and\nthe respective channel states.\n",
"title": "Adaptive Interference Removal for Un-coordinated Radar/Communication Co-existence"
}
| null | null | null | null | true | null |
15717
| null |
Default
| null | null |
null |
{
"abstract": " In many settings, it is important that a model be capable of providing\nreasons for its predictions (i.e., the model must be interpretable). However,\nthe model's reasoning may not conform with well-established knowledge. In such\ncases, while interpretable, the model lacks \\textit{credibility}. In this work,\nwe formally define credibility in the linear setting and focus on techniques\nfor learning models that are both accurate and credible. In particular, we\npropose a regularization penalty, expert yielded estimates (EYE), that\nincorporates expert knowledge about well-known relationships among covariates\nand the outcome of interest. We give both theoretical and empirical results\ncomparing our proposed method to several other regularization techniques.\nAcross a range of settings, experiments on both synthetic and real data show\nthat models learned using the EYE penalty are significantly more credible than\nthose learned using other penalties. Applied to a large-scale patient risk\nstratification task, our proposed technique results in a model whose top\nfeatures overlap significantly with known clinical risk factors, while still\nachieving good predictive performance.\n",
"title": "Learning Credible Models"
}
| null | null | null | null | true | null |
15718
| null |
Default
| null | null |
null |
{
"abstract": " In a language corpus, the probability that a word occurs $n$ times is often\nproportional to $1/n^2$. Assigning rank, $s$, to words according to their\nabundance, $\\log s$ vs $\\log n$ typically has a slope of minus one. That simple\nZipf's law pattern also arises in the population sizes of cities, the sizes of\ncorporations, and other patterns of abundance. By contrast, for the abundances\nof different biological species, the probability of a population of size $n$ is\ntypically proportional to $1/n$, declining exponentially for larger $n$, the\nlog series pattern. This article shows that the differing patterns of Zipf's\nlaw and the log series arise as the opposing endpoints of a more general\ntheory. The general theory follows from the generic form of all probability\npatterns as a consequence of conserved average values and the associated\ninvariances of scale. To understand the common patterns of abundance, the\ngeneric form of probability distributions plus the conserved average abundance\nis sufficient. The general theory includes cases that are between the Zipf and\nlog series endpoints, providing a broad framework for analyzing widely observed\nabundance patterns.\n",
"title": "The common patterns of abundance: the log series and Zipf's law"
}
| null | null | null | null | true | null |
15719
| null |
Default
| null | null |
null |
{
"abstract": " Many prediction problems, such as those that arise in the context of\nrobotics, have a simplifying underlying structure that could accelerate\nlearning. In this paper, we present a strategy for learning a set of neural\nnetwork modules that can be combined in different ways. We train different\nmodular structures on a set of related tasks and generalize to new tasks by\ncomposing the learned modules in new ways. We show this improves performance in\ntwo robotics-related problems.\n",
"title": "Modular meta-learning"
}
| null | null | null | null | true | null |
15720
| null |
Default
| null | null |
null |
{
"abstract": " We propose a universal experiment to measure the differential Casimir force\nbetween a Au-coated sphere and two halves of a structured plate covered with a\nP-doped Si overlayer. The concentration of free charge carriers in the\noverlayer is chosen slightly below the critical one, f or which the phase\ntransition from dielectric to metal occurs. One ha f of the structured plate is\ninsulating, while its second half is made of gold. For the former we consider\ntwo different structures, one consisting of bulk high-resistivity Si and the\nother of a layer of silica followed by bulk high-resistivity Si. The\ndifferential Casimir force is computed within the Lifshitz theory using four\napproaches that have been proposed in the literature to account for the role of\nfree charge carriers in metallic and dielectric materials interacting with\nquantum fluctuations. According to these approaches, Au at low frequencies is\ndescribed by either the Drude or the plasma model, whereas the free charge\ncarriers in dielectric materials at room temperature are either taken into\naccount or disregarded. It is shown that the values of differential Casimir\nforces, computed in the micrometer separation range using these four\napproaches, are widely distinct from each other and can be easily discriminated\nexperimentally. It is shown that for all approaches the thermal component of\nthe differential Casimir force is sufficiently large for direct observation.\nThe possible errors and uncertainties in the proposed experiment are estimated\nand its importance for the theory of quantum fluctuations is discussed.\n",
"title": "Universal experimental test for the role of free charge carriers in thermal Casimir effect within a micrometer separation range"
}
| null | null | null | null | true | null |
15721
| null |
Default
| null | null |
null |
{
"abstract": " We derive an explicit formula for the scalar curvature over a two-torus with\na Dirac operator conformally rescaled by a globally diagonalizable matrix. We\nshow that the Gauss-Bonnet theorem holds and extend the result to all Riemann\nsurfaces with Dirac operators modified in the same way.\n",
"title": "Gauss-Bonnet for matrix conformally rescaled Dirac"
}
| null | null |
[
"Mathematics"
] | null | true | null |
15722
| null |
Validated
| null | null |
null |
{
"abstract": " This paper presents a multi-pose face recognition approach using hybrid face\nfeatures descriptors (HFFD). The HFFD is a face descriptor containing of rich\ndiscriminant information that is created by fusing some frequency-based\nfeatures extracted using both wavelet and DCT analysis of several different\nposes of 2D face images. The main aim of this method is to represent the\nmulti-pose face images using a dominant frequency component with still having\nreasonable achievement compared to the recent multi-pose face recognition\nmethods. The HFFD based face recognition tends to achieve better performance\nthan that of the recent 2D-based face recognition method. In addition, the\nHFFD-based face recognition also is sufficiently to handle large face\nvariability due to face pose variations .\n",
"title": "Multi-Pose Face Recognition Using Hybrid Face Features Descriptor"
}
| null | null | null | null | true | null |
15723
| null |
Default
| null | null |
null |
{
"abstract": " The twisted equivariant K-theory given by Freed and Moore is a K-theory which\nunifies twisted equivariant complex K-theory, Atiyah's `Real' K-theory, and\ntheir variants. In a general setting, we formulate this K-theory by using\nFredholm operators, and establish basic properties such as the Bott periodicity\nand the Thom isomorphism. We also provide formulations of the K-theory based on\nKaroubi's gradations in both infinite and finite dimensions, clarifying their\nrelationship with the Fredholm formulation.\n",
"title": "Freed-Moore K-theory"
}
| null | null | null | null | true | null |
15724
| null |
Default
| null | null |
null |
{
"abstract": " We report observations of magnetoresistance, quantum oscillations and\nangle-resolved photoemission in RhSb$_3$, a unfilled skutterudite semimetal\nwith low carrier density. The calculated electronic band structure of RhSb$_3$\nentails a $Z_2$ quantum number $\\nu_0=0,\\nu_1=\\nu_2=\\nu_3=1$ in analogy to\nstrong topological insulators, and inverted linear valence/conduction bands\nthat touch at discrete points close to the Fermi level, in agreement with\nangle-resolved photoemission results. Transport experiments reveal an\nunsaturated linear magnetoresistance that approaches a factor of 200 at 60 T\nmagnetic fields, and quantum oscillations observable up to 150~K that are\nconsistent with a large Fermi velocity ($\\sim 1.3\\times 10^6$ ms$^{-1}$), high\ncarrier mobility ($\\sim 14$ $m^2$/Vs), and small three dimensional hole pockets\nwith nontrivial Berry phase. A very small, sample-dependent effective mass that\nfalls as low as $0.015(7)$ bare masses scales with Fermi velocity, suggesting\nRhSb$_3$ is a new class of zero-gap three-dimensional Dirac semimetal.\n",
"title": "Dirac dispersion and non-trivial Berry's phase in three-dimensional semimetal RhSb3"
}
| null | null | null | null | true | null |
15725
| null |
Default
| null | null |
null |
{
"abstract": " Fréchet mean and variance provide a way of obtaining mean and variance for\ngeneral metric space valued random variables and can be used for statistical\nanalysis of data objects that lie in abstract spaces devoid of algebraic\nstructure and operations. Examples of such spaces include covariance matrices,\ngraph Laplacians of networks and univariate probability distribution functions.\nWe derive a central limit theorem for Fréchet variance under mild regularity\nconditions, utilizing empirical process theory, and also provide a consistent\nestimator of the asymptotic variance. These results lead to a test to compare k\npopulations based on Fréchet variance for general metric space valued data\nobjects, with emphasis on comparing means and variances. We examine the finite\nsample performance of this inference procedure through simulation studies for\nseveral special cases that include probability distributions and graph\nLaplacians, which leads to tests to compare populations of networks. The\nproposed methodology has good finite sample performance in simulations for\ndifferent kinds of random objects. We illustrate the proposed methods with data\non mortality profiles of various countries and resting state Functional\nMagnetic Resonance Imaging data.\n",
"title": "Fréchet Analysis Of Variance For Random Objects"
}
| null | null | null | null | true | null |
15726
| null |
Default
| null | null |
null |
{
"abstract": " The \"backward simulation\" of a stochastic process is defined as the\nstochastic dynamics that trace a time-reversed path from the target region to\nthe initial configuration. If the probabilities calculated by the original\nsimulation are easily restored from those obtained by backward dynamics, we can\nuse it as a computational tool. It is shown that the naive approach to backward\nsimulation does not work as expected. As a remedy, the Time Reverse Monte Carlo\nmethod (TRMC) based on the ideas of Sequential Importance Sampling (SIS) and\nSequential Monte Carlo (SMC) is proposed and successfully tested with a\nstochastic typhoon model and the Lorenz 96 model. TRMC with SMC, which contains\nresampling steps, is shown to be more efficient for simulations with a larger\nnumber of time steps. A limitation of TRMC and its relation to the Bayes\nformula are also discussed.\n",
"title": "Backward Simulation of Stochastic Process using a Time Reverse Monte Carlo method"
}
| null | null | null | null | true | null |
15727
| null |
Default
| null | null |
null |
{
"abstract": " We present Spectral Inference Networks, a framework for learning\neigenfunctions of linear operators by stochastic optimization. Spectral\nInference Networks generalize Slow Feature Analysis to generic symmetric\noperators, and are closely related to Variational Monte Carlo methods from\ncomputational physics. As such, they can be a powerful tool for unsupervised\nrepresentation learning from video or pairs of data. We derive a training\nalgorithm for Spectral Inference Networks that addresses the bias in the\ngradients due to finite batch size and allows for online learning of multiple\neigenfunctions. We show results of training Spectral Inference Networks on\nproblems in quantum mechanics and feature learning for videos on synthetic\ndatasets as well as the Arcade Learning Environment. Our results demonstrate\nthat Spectral Inference Networks accurately recover eigenfunctions of linear\noperators, can discover interpretable representations from video and find\nmeaningful subgoals in reinforcement learning environments.\n",
"title": "Spectral Inference Networks: Unifying Spectral Methods With Deep Learning"
}
| null | null | null | null | true | null |
15728
| null |
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| null | null |
null |
{
"abstract": " Appropriate models for spatially autocorrelated data account for the fact\nthat observations are not independent. A popular model in this context is the\nsimultaneous autoregressive (SAR) model that allows to model the spatial\ndependency structure of a response variable and the influence of covariates on\nthis variable. This spatial regression model assumes that the error follows a\nnormal distribution. Since this assumption cannot always be met, it is\nnecessary to extend this model to other error distributions. We propose the\nextension to the $t$-distribution, the tSAR model, which can be used if we\nobserve heavy tails in the fitted residuals of the SAR model. In addition, we\nprovide a variance estimate that considers the spatial structure of a variable\nwhich helps us to specify inputs for our models. An extended simulation study\nshows that the proposed estimators of the tSAR model are performing well and in\nan application to fire danger we see that the tSAR model is a notable\nimprovement compared to the SAR model.\n",
"title": "Heavy tailed spatial autocorrelation models"
}
| null | null | null | null | true | null |
15729
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| null | null |
null |
{
"abstract": " We investigate learning of the differential geometric structure of a data\nmanifold embedded in a high-dimensional Euclidean space. We first analyze\nkernel-based algorithms and show that under the usual regularizations,\nnon-probabilistic methods cannot recover the differential geometric structure,\nbut instead find mostly linear manifolds or spaces equipped with teleports. To\nproperly learn the differential geometric structure, non-probabilistic methods\nmust apply regularizations that enforce large gradients, which go against\ncommon wisdom. We repeat the analysis for probabilistic methods and find that\nunder reasonable priors, the geometric structure can be recovered. Fully\nexploiting the recovered structure, however, requires the development of\nstochastic extensions to classic Riemannian geometry. We take early steps in\nthat regard. Finally, we partly extend the analysis to modern models based on\nneural networks, thereby highlighting geometric and probabilistic shortcomings\nof current deep generative models.\n",
"title": "Only Bayes should learn a manifold (on the estimation of differential geometric structure from data)"
}
| null | null | null | null | true | null |
15730
| null |
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| null | null |
null |
{
"abstract": " To investigate whether training load monitoring data could be used to predict\ninjuries in elite Australian football players, data were collected from elite\nathletes over 3 seasons at an Australian football club. Loads were quantified\nusing GPS devices, accelerometers and player perceived exertion ratings.\nAbsolute and relative training load metrics were calculated for each player\neach day (rolling average, exponentially weighted moving average, acute:chronic\nworkload ratio, monotony and strain). Injury prediction models (regularised\nlogistic regression, generalised estimating equations, random forests and\nsupport vector machines) were built for non-contact, non-contact time-loss and\nhamstring specific injuries using the first two seasons of data. Injury\npredictions were generated for the third season and evaluated using the area\nunder the receiver operator characteristic (AUC). Predictive performance was\nonly marginally better than chance for models of non-contact and non-contact\ntime-loss injuries (AUC$<$0.65). The best performing model was a multivariate\nlogistic regression for hamstring injuries (best AUC=0.76). Learning curves\nsuggested logistic regression was underfitting the load-injury relationship and\nthat using a more complex model or increasing the amount of model building data\nmay lead to future improvements. Injury prediction models built using training\nload data from a single club showed poor ability to predict injuries when\ntested on previously unseen data, suggesting they are limited as a daily\ndecision tool for practitioners. Focusing the modelling approach on specific\ninjury types and increasing the amount of training data may lead to the\ndevelopment of improved predictive models for injury prevention.\n",
"title": "Predictive modelling of training loads and injury in Australian football"
}
| null | null | null | null | true | null |
15731
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| null | null |
null |
{
"abstract": " We spectroscopically investigate the hyperfine, rotational and Zeeman\nstructure of the vibrational levels $\\text{v}'=0$, $7$, $13$ within the\nelectronically excited $c^3\\Sigma_g^+$ state of $^{87}\\text{Rb}_2$ for magnetic\nfields of up to $1000\\,\\text{G}$. As spectroscopic methods we use short-range\nphotoassociation of ultracold Rb atoms as well as photoexcitation of ultracold\nmolecules which have been previously prepared in several well-defined quantum\nstates of the $a^3\\Sigma_u^+$ potential. As a byproduct, we present optical\ntwo-photon transfer of weakly bound Feshbach molecules into $a^3\\Sigma_u^+$,\n$\\text{v}=0$ levels featuring different nuclear spin quantum numbers. A simple\nmodel reproduces well the molecular level structures of the $c^3\\Sigma_g^+$\nvibrational states and provides a consistent assignment of the measured\nresonance lines. Furthermore, the model can be used to predict the relative\ntransition strengths of the lines. From fits to the data we extract for each\nvibrational level the rotational constant, the effective spin-spin interaction\nconstant, as well as the Fermi contact parameter and (for the first time) the\nanisotropic hyperfine constant. In an alternative approach, we perform\ncoupled-channel calculations where we fit the relevant potential energy curves,\nspin-orbit interactions and hyperfine functions. The calculations reproduce the\nmeasured hyperfine level term frequencies with an average uncertainty of\n$\\pm9\\:$MHz, similar as for the simple model. From these fits we obtain a\nsection of the potential energy curve for the $c^3\\Sigma_g^+$ state which can\nbe used for predicting the level structure for the vibrational manifold\n$\\text{v}'=0$ to $13$ of this electronic state.\n",
"title": "Level structure of deeply bound levels of the $c^3Σ_g^+$ state of $^{87}\\text{Rb}_2$"
}
| null | null | null | null | true | null |
15732
| null |
Default
| null | null |
null |
{
"abstract": " We describe a Hopf ring structure on the direct sum of the cohomology groups\n$\\bigoplus_{n \\geq 0} H^* \\left( B_n; \\mathbb{Z}_2 \\right)$ of the Coxeter\ngroups of type $B_n$, and an almost-Hopf ring structure on the direct sum of\nthe cohomology groups $\\bigoplus_{n \\geq 0} H^* \\left( D_n; \\mathbb{Z}_2\n\\right)$ of the Coxeter groups of type $D_n$, with coefficient in the field\nwith two elements $\\mathbb{Z}_2$. We give presentations with generators and\nrelations, determine additive bases and compute the Steenrod algebra action.\nThe generators are described both in terms of a geometric construction by De\nConcini and Salvetti and in terms of their restriction to elementary abelian\n2-subgroups.\n",
"title": "The mod 2 cohomology of the infinite families of Coxeter groups of type B and D as almost Hopf rings"
}
| null | null | null | null | true | null |
15733
| null |
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| null | null |
null |
{
"abstract": " In one-way quantum computation (1WQC) model, an initial highly entangled\nstate called a graph state is used to perform universal quantum computations by\na sequence of adaptive single-qubit measurements and post-measurement Pauli-X\nand Pauli-Z corrections. The needed computations are organized as measurement\npatterns, or simply patterns, in the 1WQC model. The entanglement operations in\na pattern can be shown by a graph which together with the set of its input and\noutput qubits is called the geometry of the pattern. Since a one-way quantum\ncomputation pattern is based on quantum measurements, which are fundamentally\nnondeterministic evolutions, there must be conditions over geometries to\nguarantee determinism. Causal flow is a sufficient and generalized flow (gflow)\nis a necessary and sufficient condition over geometries to identify a\ndependency structure for the measurement sequences in order to achieve\ndeterminism. Previously, three optimization methods have been proposed to\nsimplify 1WQC patterns which are called standardization, signal shifting and\nPauli simplification. These optimizations can be performed using measurement\ncalculus formalism by rewriting rules. However, maintaining and searching these\nrules in the library can be complicated with respect to implementation.\nMoreover, serial execution of these rules is time consuming due to executing\nmany ineffective commutation rules. To overcome this problem, in this paper, a\nnew scheme is proposed to perform optimization techniques on patterns with flow\nor gflow only based on their geometries instead of using rewriting rules.\nFurthermore, the proposed scheme obtains the maximally delayed gflow order for\ngeometries with flow. It is shown that the time complexity of the proposed\napproach is improved over the previous ones.\n",
"title": "Geometry-Based Optimization of One-Way Quantum Computation Measurement Patterns"
}
| null | null | null | null | true | null |
15734
| null |
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| null | null |
null |
{
"abstract": " In this note, we shall compute the categorical entropy of an autoequivalence\non a generic abelian surface.\n",
"title": "Categorical entropy for Fourier-Mukai transforms on generic abelian surfaces"
}
| null | null | null | null | true | null |
15735
| null |
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| null | null |
null |
{
"abstract": " With the development and widespread use of wireless devices in recent years\n(mobile phones, Internet of Things, Wi-Fi), the electromagnetic spectrum has\nbecome extremely crowded. In order to counter security threats posed by rogue\nor unknown transmitters, it is important to identify RF transmitters not by the\ndata content of the transmissions but based on the intrinsic physical\ncharacteristics of the transmitters. RF waveforms represent a particular\nchallenge because of the extremely high data rates involved and the potentially\nlarge number of transmitters present in a given location. These factors outline\nthe need for rapid fingerprinting and identification methods that go beyond the\ntraditional hand-engineered approaches. In this study, we investigate the use\nof machine learning (ML) strategies to the classification and identification\nproblems, and the use of wavelets to reduce the amount of data required. Four\ndifferent ML strategies are evaluated: deep neural nets (DNN), convolutional\nneural nets (CNN), support vector machines (SVM), and multi-stage training\n(MST) using accelerated Levenberg-Marquardt (A-LM) updates. The A-LM MST method\npreconditioned by wavelets was by far the most accurate, achieving 100%\nclassification accuracy of transmitters, as tested using data originating from\n12 different transmitters. We discuss strategies for extension of MST to a much\nlarger number of transmitters.\n",
"title": "Machine Learning Approach to RF Transmitter Identification"
}
| null | null | null | null | true | null |
15736
| null |
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| null | null |
null |
{
"abstract": " In the study of subdiffusive wave-packet spreading in disordered Klein-Gordon\n(KG) nonlinear lattices, a central open question is whether the motion\ncontinues to be chaotic despite decreasing densities, or tends to become\nquasi-periodic as nonlinear terms become negligible. In a recent study of such\nKG particle chains with quartic (4th order) anharmonicity in the on-site\npotential, it was shown that $q-$Gaussian probability distribution functions of\nsums of position observables with $q > 1$ always approach pure Gaussians\n($q=1$) in the long time limit and hence the motion of the full system is\nultimately \"strongly chaotic\". In the present paper, we show that these results\ncontinue to hold even when a sextic (6th order) term is gradually added to the\npotential and ultimately prevails over the 4th order anharmonicity, despite\nexpectations that the dynamics is more \"regular\", at least in the regime of\nsmall oscillations. Analyzing this system in the subdiffusive energy domain\nusing $q$-statistics, we demonstrate that groups of oscillators centered around\nthe initially excited one (as well as the full chain) possess strongly chaotic\ndynamics and are thus far from any quasi-periodic torus, for times as long as\n$t=10^9$.\n",
"title": "Analyzing Chaos in Higher Order Disordered Quartic-Sextic Klein-Gordon Lattices Using $q$-Statistics"
}
| null | null | null | null | true | null |
15737
| null |
Default
| null | null |
null |
{
"abstract": " The origin of the activity in the solar corona is a long-standing problem in\nsolar physics. Recent satellite observations, such as Hinode, Solar Dynamics\nObservatory (SDO), Interface Region Imaging Spectrograph (IRIS), show the\ndetail characteristics of the solar atmosphere and try to reveal the energy\ntransfer from the photosphere to the corona through the magnetic fields and its\nenergy conversion by various processes. However, quantitative estimation of\nenergy transfer along the magnetic field is not enough. There are mainly two\nreason why it is difficult to observe the energy transfer from photosphere to\ncorona; 1) spatial resolution gap between photosphere (a few 0.1 arcsec) and\ncorona (a few arcsec), 2) lack in temperature coverage. Furthermore, there is\nnot enough observational knowledge of the physical parameters in the energy\ndissipation region. There are mainly three reason why it is difficult to\nobserve in the vicinity of the energy dissipation region; 1) small spatial\nscale, 2) short time scale, 3) low emission. It is generally believed that the\nenergy dissipation occurs in the very small scale and its duration is very\nshort (10 second). Further, the density in the dissipation region might be very\nlow. Therefore, the high spatial and temporal resolution UV/EUV spectroscopic\nobservation with wide temperature coverage is crucial to estimate the energy\ntransport from photosphere to corona quantitatively and diagnose the plasma\ndynamics in the vicinity of the energy dissipation region. Main Science Target\nfor the telescope is quantitative estimation for the energy transfer from the\nphotosphere to the corona, and clarification of the plasma dynamics in the\nvicinity of the energy dissipation region, where is the key region for coronal\nheating, solar wind acceleration, and/or solar flare, by the high spatial and\ntemporal resolution UV/EUV spectroscopy.\n",
"title": "UV/EUV High-Throughput Spectroscopic Telescope: A Next Generation Solar Physics Mission white paper"
}
| null | null |
[
"Physics"
] | null | true | null |
15738
| null |
Validated
| null | null |
null |
{
"abstract": " Online creative communities have been able to develop large, open source\nsoftware (OSS) projects like Linux and Firefox throughout the successful\ncollaborations carried out over the Internet. These communities have also\nexpanded to creative arts domains such as animation, video games, and music.\nDespite their growing popularity, the factors that lead to successful\ncollaborations in these communities are not entirely understood. In the\nfollowing, I describe my PhD research project aimed at improving communication,\ncollaboration, and retention in creative arts communities, starting from the\nexperience gained from the literature about OSS communities.\n",
"title": "Investigating Collaboration Within Online Communities: Software Development Vs. Artistic Creation"
}
| null | null | null | null | true | null |
15739
| null |
Default
| null | null |
null |
{
"abstract": " The mutual-exclusion property of locks stands in the way to scalability of\nparallel programs on many-core architectures. Locks do not allow progress\nguarantees, because a task may fail inside a critical section and keep holding\na lock that blocks other tasks from accessing shared data. With non-blocking\nsynchronization, the drawbacks of locks are avoided by synchronizing access to\nshared data by atomic read-modify-write operations. To incorporate non-blocking\nsynchronization in Ada~202x, programmers must be able to reason about the\nbehavior and performance of tasks in the absence of protected objects and\nrendezvous. We therefore extend Ada's memory model by synchronized types, which\nsupport the expression of memory ordering operations at a sufficient level of\ndetail. To mitigate the complexity associated with non-blocking\nsynchronization, we propose concurrent objects as a novel high-level language\nconstruct. Entities of a concurrent object execute in parallel, due to a\nfine-grained, optimistic synchronization mechanism. Synchronization is framed\nby the semantics of concurrent entry execution. The programmer is only required\nto label shared data accesses in the code of concurrent entries. Labels\nconstitute memory-ordering operations expressed through attributes. To the best\nof our knowledge, this is the first approach to provide a non-blocking\nsynchronization construct as a first-class citizen of a high-level programming\nlanguage. We illustrate the use of concurrent objects by several examples.\n",
"title": "Safe Non-blocking Synchronization in Ada 202x"
}
| null | null | null | null | true | null |
15740
| null |
Default
| null | null |
null |
{
"abstract": " The concepts of unitary evolution matrices and associative memory have\nboosted the field of Recurrent Neural Networks (RNN) to state-of-the-art\nperformance in a variety of sequential tasks. However, RNN still have a limited\ncapacity to manipulate long-term memory. To bypass this weakness the most\nsuccessful applications of RNN use external techniques such as attention\nmechanisms. In this paper we propose a novel RNN model that unifies the\nstate-of-the-art approaches: Rotational Unit of Memory (RUM). The core of RUM\nis its rotational operation, which is, naturally, a unitary matrix, providing\narchitectures with the power to learn long-term dependencies by overcoming the\nvanishing and exploding gradients problem. Moreover, the rotational unit also\nserves as associative memory. We evaluate our model on synthetic memorization,\nquestion answering and language modeling tasks. RUM learns the Copying Memory\ntask completely and improves the state-of-the-art result in the Recall task.\nRUM's performance in the bAbI Question Answering task is comparable to that of\nmodels with attention mechanism. We also improve the state-of-the-art result to\n1.189 bits-per-character (BPC) loss in the Character Level Penn Treebank (PTB)\ntask, which is to signify the applications of RUM to real-world sequential\ndata. The universality of our construction, at the core of RNN, establishes RUM\nas a promising approach to language modeling, speech recognition and machine\ntranslation.\n",
"title": "Rotational Unit of Memory"
}
| null | null | null | null | true | null |
15741
| null |
Default
| null | null |
null |
{
"abstract": " Gene regulatory networks play a crucial role in controlling an organism's\nbiological processes, which is why there is significant interest in developing\ncomputational methods that are able to extract their structure from\nhigh-throughput genetic data. A typical approach consists of a series of\nconditional independence tests on the covariance structure meant to\nprogressively reduce the space of possible causal models. We propose a novel\nefficient Bayesian method for discovering the local causal relationships among\ntriplets of (normally distributed) variables. In our approach, we score the\npatterns in the covariance matrix in one go and we incorporate the available\nbackground knowledge in the form of priors over causal structures. Our method\nis flexible in the sense that it allows for different types of causal\nstructures and assumptions. We apply the approach to the task of inferring gene\nregulatory networks by learning regulatory relationships between gene\nexpression levels. We show that our algorithm produces stable and conservative\nposterior probability estimates over local causal structures that can be used\nto derive an honest ranking of the most meaningful regulatory relationships. We\ndemonstrate the stability and efficacy of our method both on simulated data and\non real-world data from an experiment on yeast.\n",
"title": "A Bayesian Approach for Inferring Local Causal Structure in Gene Regulatory Networks"
}
| null | null |
[
"Statistics",
"Quantitative Biology"
] | null | true | null |
15742
| null |
Validated
| null | null |
null |
{
"abstract": " In this paper, we discuss recent results about generalized metric spaces and\nfixed point theory. We introduce the notion of $\\eta$-cone metric spaces, give\nsome topological properties and prove some fixed point theorems for contractive\ntype maps on these spaces. In particular we show that theses $\\eta$-cone metric\nspaces are natural generalizations of both cone metric spaces and metric type\nspaces.\n",
"title": "$η$-metric structures"
}
| null | null | null | null | true | null |
15743
| null |
Default
| null | null |
null |
{
"abstract": " In the present paper we demonstrate the results of a statistical analysis of\nsome characteristics of precipitation events and propose a kind of a\ntheoretical explanation of the proposed models in terms of mixed Poisson and\nmixed exponential distributions based on the information-theoretical entropy\nreasoning. The proposed models can be also treated as the result of following\nthe popular Bayesian approach.\n",
"title": "Statistical Analysis of Precipitation Events"
}
| null | null | null | null | true | null |
15744
| null |
Default
| null | null |
null |
{
"abstract": " Vision-language navigation (VLN) is the task of navigating an embodied agent\nto carry out natural language instructions inside real 3D environments. In this\npaper, we study how to address three critical challenges for this task: the\ncross-modal grounding, the ill-posed feedback, and the generalization problems.\nFirst, we propose a novel Reinforced Cross-Modal Matching (RCM) approach that\nenforces cross-modal grounding both locally and globally via reinforcement\nlearning (RL). Particularly, a matching critic is used to provide an intrinsic\nreward to encourage global matching between instructions and trajectories, and\na reasoning navigator is employed to perform cross-modal grounding in the local\nvisual scene. Evaluation on a VLN benchmark dataset shows that our RCM model\nsignificantly outperforms existing methods by 10% on SPL and achieves the new\nstate-of-the-art performance. To improve the generalizability of the learned\npolicy, we further introduce a Self-Supervised Imitation Learning (SIL) method\nto explore unseen environments by imitating its own past, good decisions. We\ndemonstrate that SIL can approximate a better and more efficient policy, which\ntremendously minimizes the success rate performance gap between seen and unseen\nenvironments (from 30.7% to 11.7%).\n",
"title": "Reinforced Cross-Modal Matching and Self-Supervised Imitation Learning for Vision-Language Navigation"
}
| null | null | null | null | true | null |
15745
| null |
Default
| null | null |
null |
{
"abstract": " Fermilab is committed to upgrading its accelerator complex towards the\nintensity frontier to pursue HEP research in the neutrino sector and beyond.\nThe upgrade has two steps: 1) the Proton Improvement Plan (PIP), which is\nunderway, has its primary goal to start providing 700 kW beam power on NOvA\ntarget by the end of 2017 and 2) the foreseen PIP-II will replace the existing\nLINAC, a 400 MeV injector to the Booster, by an 800 MeV superconducting LINAC\nby the middle of next decade, with output beam intensity from the Booster\nincreased significantly and the beam power on the NOvA target increased to <1.2\nMW. In any case, the Fermilab Booster is going to play a very significant role\nfor the next two decades. In this context, we have recently developed and\ncommissioned an innovative beam injection scheme for the Booster called \"early\ninjection scheme.\" This scheme is already in operation and has a potential to\nincrease the Booster beam intensity from the PIP design goal by a considerable\namount with a reduced beam emittance and beam loss. In this paper, we will\npresent results from our experience from the new scheme in operation, current\nstatus and future plans.\n",
"title": "Proton Beam Intensity Upgrades for the Neutrino Program at Fermilab"
}
| null | null | null | null | true | null |
15746
| null |
Default
| null | null |
null |
{
"abstract": " For a given cluster-tilted algebra $A$ of tame type, it is proved that\ndifferent indecomposable $\\tau$-rigid $A$-modules have different dimension\nvectors. This is motivated by Fomin-Zelevinsky's denominator conjecture for\ncluster algebras. As an application, we establish a weak version of the\ndenominator conjecture for cluster algebras of tame type. Namely, we show that\ndifferent cluster variables have different denominators with respect to a given\ncluster for a cluster algebra of tame type. Our approach involves\nIyama-Yoshino's construction of subfactors of triangulated categories. In\nparticular,we obtain a description of the subfactors of cluster categories of\ntame type with respect to an indecomposable rigid object, which is of\nindependent interest.\n",
"title": "On indecomposable $τ$-rigid modules over cluster-tilted algebras of tame type"
}
| null | null | null | null | true | null |
15747
| null |
Default
| null | null |
null |
{
"abstract": " This article discusses how the automation of tensor algorithms, based on A\nMathematics of Arrays and Psi Calculus, and a new way to represent numbers,\nUnum Arithmetic, enables mechanically provable, scalable, portable, and more\nnumerically accurate software.\n",
"title": "Tensors Come of Age: Why the AI Revolution will help HPC"
}
| null | null | null | null | true | null |
15748
| null |
Default
| null | null |
null |
{
"abstract": " Conventional methods of estimating latent behaviour generally use attitudinal\nquestions which are subjective and these survey questions may not always be\navailable. We hypothesize that an alternative approach can be used for latent\nvariable estimation through an undirected graphical models. For instance,\nnon-parametric artificial neural networks. In this study, we explore the use of\ngenerative non-parametric modelling methods to estimate latent variables from\nprior choice distribution without the conventional use of measurement\nindicators. A restricted Boltzmann machine is used to represent latent\nbehaviour factors by analyzing the relationship information between the\nobserved choices and explanatory variables. The algorithm is adapted for latent\nbehaviour analysis in discrete choice scenario and we use a graphical approach\nto evaluate and understand the semantic meaning from estimated parameter vector\nvalues. We illustrate our methodology on a financial instrument choice dataset\nand perform statistical analysis on parameter sensitivity and stability. Our\nfindings show that through non-parametric statistical tests, we can extract\nuseful latent information on the behaviour of latent constructs through machine\nlearning methods and present strong and significant influence on the choice\nprocess. Furthermore, our modelling framework shows robustness in input\nvariability through sampling and validation.\n",
"title": "Discriminative conditional restricted Boltzmann machine for discrete choice and latent variable modelling"
}
| null | null | null | null | true | null |
15749
| null |
Default
| null | null |
null |
{
"abstract": " We propose a rescaled LASSO, by premultipying the LASSO with a matrix term,\nnamely linear unified LASSO (LLASSO) for multicollinear situations. Our\nnumerical study has shown that the LLASSO is comparable with other sparse\nmodeling techniques and often outperforms the LASSO and elastic net. Our\nfindings open new visions about using the LASSO still for sparse modeling and\nvariable selection. We conclude our study by pointing that the LLASSO can be\nsolved by the same efficient algorithm for solving the LASSO and suggest to\nfollow the same construction technique for other penalized estimators.\n",
"title": "LLASSO: A linear unified LASSO for multicollinear situations"
}
| null | null |
[
"Statistics"
] | null | true | null |
15750
| null |
Validated
| null | null |
null |
{
"abstract": " We present the results of smoothed particle hydrodynamic simulations\ninvestigating the evolution and fragmentation of filaments that are accreting\nfrom a turbulent medium. We show that the presence of turbulence, and the\nresulting inhomogeneities in the accretion flow, play a significant role in the\nfragmentation process. Filaments which experience a weakly turbulent accretion\nflow fragment in a two-tier hierarchical fashion, similar to the fragmentation\npattern seen in the Orion Integral Shaped Filament. Increasing the energy in\nthe turbulent velocity field results in more sub-structure within the\nfilaments, and one sees a shift from gravity-dominated fragmentation to\nturbulence-dominated fragmentation. The sub-structure formed in the filaments\nis elongated and roughly parallel to the longitudinal axis of the filament,\nsimilar to the fibres seen in observations of Taurus, and suggests that the\nfray and fragment scenario is a possible mechanism for the production of\nfibres. We show that the formation of these fibre-like structures is linked to\nthe vorticity of the velocity field inside the filament and the filament's\naccretion from an inhomogeneous medium. Moreover, we find that accretion is\nable to drive and sustain roughly sonic levels of turbulence inside the\nfilaments, but is not able to prevent radial collapse once the filaments become\nsupercritical. However, the supercritical filaments which contain fibre-like\nstructures do not collapse radially, suggesting that fibrous filaments may not\nnecessarily become radially unstable once they reach the critical line-density.\n",
"title": "Filamentary fragmentation in a turbulent medium"
}
| null | null | null | null | true | null |
15751
| null |
Default
| null | null |
null |
{
"abstract": " Redox flow batteries (RFBs) are potential solutions for grid-scale energy\nstorage, and deeper understanding of the effect of flow rate on RFB performance\nis needed to develop efficient, low-cost designs. In this study we highlight\nthe importance of modeling tanks, which can limit the charge/discharge capacity\nof redox-active polymer (RAP) based RFBs. The losses due to tank mixing\ndominate over the polarization-induced capacity losses that arise due to\nresistive processes in the reactor. A porous electrode model is used to\nseparate these effects by predicting the time variation of active species\nconcentration in electrodes and tanks. A simple transient model based on\nspecies conservation laws developed in this study reveals that charge\nutilization and polarization are affected by two dimensionless numbers\nquantifying (1) flow rate relative to stoichiometric flow and (2) size of flow\nbattery tanks relative to the reactor. The RFB's utilization is shown to\nincrease monotonically with flow rate, reaching 90% of the theoretical value\nonly when flow rate exceeds twenty-fold of the stoichiometric value. We also\nidentify polarization due to irreversibilities inherent to RFB architecture as\na result of tank mixing and current distribution internal to the reactor, and\nthis polarization dominates over that resulting from ohmic resistances\nparticularly when cycling RFBs at low flow rates and currents. These findings\nare summarized in a map of utilization and polarization that can be used to\nselect adequate flow rate for a given tank size.\n",
"title": "Uncovering the role of flow rate in redox-active polymer flow batteries: simulation of reaction distributions with simultaneous mixing in tanks"
}
| null | null |
[
"Physics"
] | null | true | null |
15752
| null |
Validated
| null | null |
null |
{
"abstract": " In this work we have analyzed the magnetocaloric effect (MCE) from the\nTsallis thermostatistics formalism (TTF) point of view. The problem discussed\nhere is a two level system MCE. We have calculated, both analytically and\nnumerically, the entropy of this system as a function of the Tsallis' parameter\n(the well known q-parameter) which value depends on the extensivity (q<1) or\nnon-extensivity (q>1) of the system. Since we consider this MCE not depending\non the initial conditions, which classify our system as a non-extensive one, we\nused several greater than one q-parameters to understand the effect of the\nnonextensive formalism in the entropy as well as the magnetocaloric potential,\n$\\Delta S$. We have plotted several curves that shows precisely the behavior of\nthis effect when dealt with non-extensive statistics.\n",
"title": "The magnetocaloric effect from the point of view of Tsallis non-extensive thermostatistics"
}
| null | null | null | null | true | null |
15753
| null |
Default
| null | null |
null |
{
"abstract": " In the framework of MSSM inflation, matter and gravitino production are here\ninvestigated through the decay of the fields which are coupled to the udd\ninflaton, a gauge invariant combination of squarks. After the end of inflation,\nthe flat direction oscillates about the minimum of its potential, losing at\neach oscillation about 56% of its energy into bursts of gauge/gaugino and\nscalar quanta when crossing the origin. These particles then acquire a large\ninflaton VEV-induced mass and decay perturbatively into the MSSM quanta and\ngravitinos, transferring the inflaton energy very efficiently via instant\npreheating. Regarding thermalization, we show that the MSSM degrees of freedom\nthermalize very quickly, yet not immediately by virtue of the large vacuum\nexpectation value of the inflaton, which breaks the $SU(3)_C\\times U(1)_Y$\nsymmetry into a residual $U(1)$. The energy transfer to the MSSM quanta is very\nefficient, since full thermalization is achieved after only $\\mathcal{O}(40)$\ncomplete oscillations. The udd inflaton thus provides an extremely efficient\nreheating of the Universe, with a temperature\n$T_{reh}=\\mathcal{O}(10^8\\mathrm{GeV})$ that allows for instance several\nmechanisms of baryogenesis. We also compute the gravitino number density from\nthe perturbative decay of the flat direction and of the SUSY multiplet. We find\nthat the gravitinos are produced in negligible amount and satisfy cosmological\nbounds such as the Big Bang Nucleosynthesis (BBN) and Dark Matter (DM)\nconstraints.\n",
"title": "Reheating, thermalization and non-thermal gravitino production in MSSM inflation"
}
| null | null |
[
"Physics"
] | null | true | null |
15754
| null |
Validated
| null | null |
null |
{
"abstract": " Blind spots are one of the causes of road accidents in the hilly and flat\nareas. These blind spot accidents can be decreased by establishing an Internet\nof Vehicles (IoV) using Vehicle-2-Vehicle (V2V) and Vehicle-2-Infrastrtructure\n(V2I) communication systems. But the problem with these IoV is that most of\nthem are using DSRC or single Radio Access Technology (RAT) as a wireless\ntechnology, which has been proven to be failed for efficient communication\nbetween vehicles. Recently, Cognitive Radio (CR) based IoV have to be proven\nbest wireless communication systems for vehicular networks. However, the\nspectrum mobility is a challenging task to keep CR based vehicular networks\ninteroperable and has not been addressed sufficiently in existing research. In\nour previous research work, the Cognitive Radio Site (CR-Site) has been\nproposed as in-vehicle CR-device, which can be utilized to establish efficient\nIoV systems. H In this paper, we have introduced the Emotions Inspired\nCognitive Agent (EIC_Agent) based spectrum mobility mechanism in CR-Site and\nproposed a novel emotions controlled spectrum mobility scheme for efficient\nsyntactic interoperability between vehicles. For this purpose, a probabilistic\ndeterministic finite automaton using fear factor is proposed to perform\nefficient spectrum mobility using fuzzy logic. In addition, the quantitative\ncomputation of different fear intensity levels has been performed with the help\nof fuzzy logic. The system has been tested using active data from different GSM\nservice providers on Mangla-Mirpur road. This is supplemented by extensive\nsimulation experiments which validate the proposed scheme for CR based\nhigh-speed vehicular networks. The qualitative comparison with the\nexisting-state-of the-art has proven the superiority of the proposed emotions\ncontrolled syntactic interoperable spectrum mobility scheme within cognitive\nradio based IoV systems.\n",
"title": "Emotion Controlled Spectrum Mobility Scheme for Efficient Syntactic Interoperability In Cognitive Radio Based Internet of Vehicles"
}
| null | null | null | null | true | null |
15755
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we study Rota-Baxter modules with emphasis on the role played\nby the Rota-Baxter operators and resulting difference between Rota-Baxter\nmodules and the usual modules over an algebra. We introduce the concepts of\nfree, projective, injective and flat Rota-Baxter modules. We give the\nconstruction of free modules and show that there are enough projective,\ninjective and flat Rota-Baxter modules to provide the corresponding resolutions\nfor derived functor.\n",
"title": "Rota-Baxter modules toward derived functors"
}
| null | null | null | null | true | null |
15756
| null |
Default
| null | null |
null |
{
"abstract": " Viral videos can reach global penetration traveling through international\nchannels of communication similarly to real diseases starting from a\nwell-localized source. In past centuries, disease fronts propagated in a\nconcentric spatial fashion from the the source of the outbreak via the short\nrange human contact network. The emergence of long-distance air-travel changed\nthese ancient patterns. However, recently, Brockmann and Helbing have shown\nthat concentric propagation waves can be reinstated if propagation time and\ndistance is measured in the flight-time and travel volume weighted underlying\nair-travel network. Here, we adopt this method for the analysis of viral meme\npropagation in Twitter messages, and define a similar weighted network distance\nin the communication network connecting countries and states of the World. We\nrecover a wave-like behavior on average and assess the randomizing effect of\nnon-locality of spreading. We show that similar result can be recovered from\nGoogle Trends data as well.\n",
"title": "Video Pandemics: Worldwide Viral Spreading of Psy's Gangnam Style Video"
}
| null | null |
[
"Computer Science"
] | null | true | null |
15757
| null |
Validated
| null | null |
null |
{
"abstract": " In this work, we find an equation that relates the Ricci curvature of a\nriemannian manifold $M$ and the second fundamental forms of two orthogonal\nfoliations of complementary dimensions, $\\mathcal{F}$ and $\\mathcal{F}^{\\bot}$,\ndefined on $M$. Using this equation, we show a sufficient condition for the\nmanifold M to be locally a riemannian product of the leaves of $\\mathcal{F}$\nand $\\mathcal{F}^{\\bot}$, if one of the foliations is totally umbilical. We\nalso prove an integral formula for such foliations.\n",
"title": "Orthogonal foliations on riemannian manifolds"
}
| null | null | null | null | true | null |
15758
| null |
Default
| null | null |
null |
{
"abstract": " The Logic Programming through Prolog has been widely used for supply\npersistence in many systems that need store knowledge. Some implementations of\nProlog Programming Language used for supply persistence have bidirectional\ninterfaces with other programming languages over all with Object Oriented\nPrograming Languages. In present days is missing tools and frameworks for the\nsystems development that use logic predicate persistence in easy and agile\nform. More specifically an object oriented and logic persistence provider is\nneed in present days that allow the object manipulation in main memory and the\npersistence for this objects have a Logic Programming predicates aspect. The\npresent work introduce an object-prolog declarative mappings alternative to\nsupport by an object oriented and logic persistence provider. The proposed\nalternative consists in a correspondence of the Logic Programming predicates\nwith an Object Oriented approach, where for each element of the Logic\nProgramming one Object Oriented element makes to reciprocate. The Object\nOriented representation of Logic Programming predicates offers facility of\nmanipulation on the elements that compose a knowledge.\n",
"title": "Mapping Objects to Persistent Predicates"
}
| null | null | null | null | true | null |
15759
| null |
Default
| null | null |
null |
{
"abstract": " In the paper, we show that the transformations between modified Jacobi and\nBernstein bases of the constrained space of polynomials of degree at most $n$\ncan be performed with the complexity $O(n^2)$. As a result, the algorithm of\ndegree reduction of Bézier curves that was first presented in (Bhrawy et al.,\nJ. Comput. Appl. Math. 302 (2016), 369--384), and then corrected in (Lu and\nXiang, J. Comput. Appl. Math. 315 (2017), 65--69), can be significantly\nimproved, since the necessary transformations are done in those papers with the\ncomplexity $O(n^3)$. The comparison of running times shows that our\ntransformations are also faster in practice.\n",
"title": "Efficient modified Jacobi-Bernstein basis transformations"
}
| null | null |
[
"Mathematics"
] | null | true | null |
15760
| null |
Validated
| null | null |
null |
{
"abstract": " Let $n\\geq k\\geq 2$ be two integers and $S$ a subset of $\\{0,1,\\dots,k-1\\}$.\nThe graph $J_{S}(n,k)$ has as vertices the $k$-subsets of the $n$-set\n$[n]=\\{1,\\dots,n\\}$ and two $k$-subsets $A$ and $B$ are adjacent if $|A\\cap\nB|\\in S$. In this paper, we use Godsil-McKay switching to prove that for $m\\geq\n0$, $k\\geq \\max(m+2,3)$ and $S = \\{0, 1, ..., m\\}$, the graphs $J_S(3k-2m-1,k)$\nare not determined by spectrum and for $m\\geq 2$, $n\\geq 4m+2$ and $S =\n\\{0,1,...,m\\}$ the graphs $J_{S}(n,2m+1)$ are not determined by spectrum. We\nalso report some computational searches for Godsil-McKay switching sets in the\nunion of classes in the Johnson scheme for $k\\leq 5$.\n",
"title": "Cospectral mates for the union of some classes in the Johnson association scheme"
}
| null | null | null | null | true | null |
15761
| null |
Default
| null | null |
null |
{
"abstract": " Electromagnetic properties of single crystal terbium gallium garnet (TGG) are\ncharacterised from room down to millikelvin temperatures using the whispering\ngallery mode method. Microwave spectroscopy is performed at low powers\nequivalent to a few photons in energy and conducted as functions of the\nmagnetic field and temperature. A phase transition is detected close to the\ntemperature of 3.5 K. This is observed for multiple whispering gallery modes\ncausing an abrupt negative frequency shift and a change in transmission due to\nextra losses in the new phase caused by a change in complex magnetic\nsusceptibility.\n",
"title": "Electromagnetic properties of terbium gallium garnet at millikelvin temperatures and single photon energy"
}
| null | null |
[
"Physics"
] | null | true | null |
15762
| null |
Validated
| null | null |
null |
{
"abstract": " We set out to quantify the number density of quiescent massive compact\ngalaxies at intermediate redshifts. We determine structural parameters based on\ni-band imaging using the CFHT equatorial SDSS Stripe 82 (CS82) survey (~170 sq.\ndegrees) taking advantage of an exquisite median seeing of ~0.6''. We select\ncompact massive (M > 5x10^10 M_sun) galaxies within the redshift range of\n0.2<z<0.6. The large volume sampled allows to decrease the effect of cosmic\nvariance that has hampered the calculation of the number density for this\nenigmatic population in many previous studies. We undertake an exhaustive\nanalysis in an effort to untangle the various findings inherent to the diverse\ndefinition of compactness present in the literature. We find that the absolute\nnumber of compact galaxies is very dependent on the adopted definition and can\nchange up to a factor of >10. We systematically measure a factor of ~5 more\ncompacts at the same redshift than what was previously reported on smaller\nfields with HST imaging, which are more affected by cosmic variance. This means\nthat the decrease in number density from z ~ 1.5 to z ~ 0.2 might be only of a\nfactor of ~2-5, significantly smaller than what previously reported. This\nsupports progenitor bias as the main contributor to the size evolution. This\nmilder decrease is roughly compatible with the predictions from recent\nnumerical simulations. Only the most extreme compact galaxies, with Reff <\n1.5x( M/10^11 M_sun)^0.75 and M > 10^10.7 M_sun, appear to drop in number by a\nfactor of ~20 and hence likely experience a noticeable size evolution.\n",
"title": "The abundance of compact quiescent galaxies since z ~ 0.6"
}
| null | null | null | null | true | null |
15763
| null |
Default
| null | null |
null |
{
"abstract": " Probabilistic load forecasts provide comprehensive information about future\nload uncertainties. In recent years, many methodologies and techniques have\nbeen proposed for probabilistic load forecasting. Forecast combination, a\nwidely recognized best practice in point forecasting literature, has never been\nformally adopted to combine probabilistic load forecasts. This paper proposes a\nconstrained quantile regression averaging (CQRA) method to create an improved\nensemble from several individual probabilistic forecasts. We formulate the CQRA\nparameter estimation problem as a linear program with the objective of\nminimizing the pinball loss, with the constraints that the parameters are\nnonnegative and summing up to one. We demonstrate the effectiveness of the\nproposed method using two publicly available datasets, the ISO New England data\nand Irish smart meter data. Comparing with the best individual probabilistic\nforecast, the ensemble can reduce the pinball score by 4.39% on average. The\nproposed ensemble also demonstrates superior performance over nine other\nbenchmark ensembles.\n",
"title": "Combining Probabilistic Load Forecasts"
}
| null | null | null | null | true | null |
15764
| null |
Default
| null | null |
null |
{
"abstract": " We show non-linear stability and instability results in spherical symmetry\nfor the interior of a charged black hole -approaching a sub-extremal\nReissner-Nordström background fast enough at infinity- in presence of a\nmassive and charged scalar field, motivated by the strong cosmic censorship\nconjecture in that setting :\n1. Stability : We prove that spherically symmetric characteristic initial\ndata to the Einstein-Maxwell- Klein-Gordon equations approaching a\nReissner-Nordström background with a sufficiently decaying polynomial decay\nrate on the event horizon gives rise to a space-time possessing a Cauchy\nhorizon in a neighbourhood of time-like infinity. Moreover if the decay is even\nstronger, we prove that the spacetime metric admits a continuous extension to\nthe Cauchy horizon. This generalizes the celebrated stability result of\nDafermos for Einstein-Maxwell-real-scalar-field in spherical symmetry.\n2. Instability : We prove that for the class of space-times considered in the\nstability part, whose scalar field in addition obeys a polynomial averaged-L^2\n(consistent) lower bound on the event horizon, the scalar field obeys an\nintegrated lower bound transversally to the Cauchy horizon. As a consequence we\nprove that the non-degenerate energy is infinite on any null surface crossing\nthe Cauchy horizon and the curvature of a geodesic vector field blows up at the\nCauchy horizon near time-like infinity. This generalizes an instability result\ndue to Luk and Oh for Einstein-Maxwell-real-scalar-field in spherical symmetry.\nThis instability of the black hole interior can also be viewed as a step\ntowards the resolution of the C^2 strong cosmic censorship conjecture for\none-ended asymptotically initial data.\n",
"title": "Stability and instability of the sub-extremal Reissner-Nordström black hole interior for the Einstein-Maxwell-Klein-Gordon equations in spherical symmetry"
}
| null | null | null | null | true | null |
15765
| null |
Default
| null | null |
null |
{
"abstract": " In this article, the JAGS software program is systematically introduced to\nfit common Bayesian cognitive diagnosis models (CDMs), including the\ndeterministic inputs, noisy \"and\" gate (DINA) model, the deterministic inputs,\nnoisy \"or\" gate (DINO) model, the linear logistic model, the reduced\nreparameterized unified model (rRUM), and the log-linear CDM (LCDM). The\nunstructured latent structural model and the higher-order latent structural\nmodel are both introduced. We also show how to extend those models to consider\nthe polytomous attributes, the testlet effect, and the longitudinal diagnosis.\nFinally, an empirical example is presented as a tutorial to illustrate how to\nuse the JAGS codes in R.\n",
"title": "Using JAGS for Bayesian Cognitive Diagnosis Modeling: A Tutorial"
}
| null | null |
[
"Statistics"
] | null | true | null |
15766
| null |
Validated
| null | null |
null |
{
"abstract": " Model based iterative reconstruction (MBIR) algorithms for low-dose X-ray CT\nare computationally expensive. To address this problem, we recently proposed a\ndeep convolutional neural network (CNN) for low-dose X-ray CT and won the\nsecond place in 2016 AAPM Low-Dose CT Grand Challenge. However, some of the\ntexture were not fully recovered. To address this problem, here we propose a\nnovel framelet-based denoising algorithm using wavelet residual network which\nsynergistically combines the expressive power of deep learning and the\nperformance guarantee from the framelet-based denoising algorithms. The new\nalgorithms were inspired by the recent interpretation of the deep convolutional\nneural network (CNN) as a cascaded convolution framelet signal representation.\nExtensive experimental results confirm that the proposed networks have\nsignificantly improved performance and preserves the detail texture of the\noriginal images.\n",
"title": "Deep Convolutional Framelet Denosing for Low-Dose CT via Wavelet Residual Network"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
15767
| null |
Validated
| null | null |
null |
{
"abstract": " Negotiation diagrams are a model of concurrent computation akin to workflow\nPetri nets. Deterministic negotiation diagrams, equivalent to the much studied\nand used free-choice workflow Petri nets, are surprisingly amenable to\nverification. Soundness (a property close to deadlock-freedom) can be decided\nin PTIME. Further, other fundamental questions like computing summaries or the\nexpected cost, can also be solved in PTIME for sound deterministic negotiation\ndiagrams, while they are PSPACE-complete in the general case.\nIn this paper we generalize and explain these results. We extend the\nclassical \"meet-over-all-paths\" (MOP) formulation of static analysis problems\nto our concurrent setting, and introduce Mazurkiewicz-invariant analysis\nproblems, which encompass the questions above and new ones. We show that any\nMazurkiewicz-invariant analysis problem can be solved in PTIME for sound\ndeterministic negotiations whenever it is in PTIME for sequential\nflow-graphs---even though the flow-graph of a deterministic negotiation diagram\ncan be exponentially larger than the diagram itself. This gives a common\nexplanation to the low-complexity of all the analysis questions studied so far.\nFinally, we show that classical gen/kill analyses are also an instance of our\nframework, and obtain a PTIME algorithm for detecting anti-patterns in\nfree-choice workflow Petri nets.\nOur result is based on a novel decomposition theorem, of independent\ninterest, showing that sound deterministic negotiation diagrams can be\nhierarchically decomposed into (possibly overlapping) smaller sound diagrams.\n",
"title": "Static Analysis of Deterministic Negotiations"
}
| null | null | null | null | true | null |
15768
| null |
Default
| null | null |
null |
{
"abstract": " The theory of Hitchin systems is something like a \"global theory of Lie\ngroups\", where one works over a Riemann surface rather than just at a point.\nWe'll describe how one can take this analogy a few steps further by attempting\nto make precise the class of rich geometric objects that appear in this story\n(including the non-compact case), and discuss their classification, outlining a\ntheory of \"Dynkin diagrams\" as a step towards classifying some examples of such\nobjects.\n",
"title": "Wild character varieties, meromorphic Hitchin systems and Dynkin diagrams"
}
| null | null |
[
"Physics",
"Mathematics"
] | null | true | null |
15769
| null |
Validated
| null | null |
null |
{
"abstract": " Confidence is a fundamental concept in statistics, but there is a tendency to\nmisinterpret it as probability. In this paper, I argue that an intuitively and\nmathematically more appropriate interpretation of confidence is through\nbelief/plausibility functions, in particular, those that satisfy a certain\nvalidity property. Given their close connection with confidence, it is natural\nto ask how a valid belief/plausibility function can be constructed directly.\nThe inferential model (IM) framework provides such a construction, and here I\nprove a complete-class theorem stating that, for every nominal confidence\nregion, there exists a valid IM whose plausibility regions are contained by the\ngiven confidence region. This characterization has implications for statistics\nunderstanding and communication, and highlights the importance of belief\nfunctions and the IM framework.\n",
"title": "A mathematical characterization of confidence as valid belief"
}
| null | null | null | null | true | null |
15770
| null |
Default
| null | null |
null |
{
"abstract": " We investigate symmetry reduction of optimal control problems for\nleft-invariant control systems on Lie groups, with partial symmetry breaking\ncost functions. Our approach emphasizes the role of variational principles and\nconsiders a discrete-time setting as well as the standard continuous-time\nformulation. Specifically, we recast the optimal control problem as a\nconstrained variational problem with a partial symmetry breaking Lagrangian and\nobtain the Euler--Poincaré equations from a variational principle. By\napplying a Legendre transformation to it, we recover the Lie-Poisson equations\nobtained by A. D. Borum [Master's Thesis, University of Illinois at\nUrbana-Champaign, 2015] in the same context. We also discretize the variational\nprinciple in time and obtain the discrete-time Lie-Poisson equations. We\nillustrate the theory with some practical examples including a motion planning\nproblem in the presence of an obstacle.\n",
"title": "Optimal Control Problems with Symmetry Breaking Cost Functions"
}
| null | null | null | null | true | null |
15771
| null |
Default
| null | null |
null |
{
"abstract": " We provide a new and simple characterization of the multivariate generalized\nLaplace distribution. In particular, this result implies that the product of a\nGaussian matrix with independent and identically distributed columns by an\nindependent isotropic Gaussian vector follows a symmetric multivariate\ngeneralized Laplace distribution.\n",
"title": "Multiplying a Gaussian Matrix by a Gaussian Vector"
}
| null | null | null | null | true | null |
15772
| null |
Default
| null | null |
null |
{
"abstract": " Accelerated gradient (AG) methods are breakthroughs in convex optimization,\nimproving the convergence rate of the gradient descent method for optimization\nwith smooth functions. However, the analysis of AG methods for non-convex\noptimization is still limited. It remains an open question whether AG methods\nfrom convex optimization can accelerate the convergence of the gradient descent\nmethod for finding local minimum of non-convex optimization problems. This\npaper provides an affirmative answer to this question. In particular, we\nanalyze two renowned variants of AG methods (namely Polyak's Heavy Ball method\nand Nesterov's Accelerated Gradient method) for extracting the negative\ncurvature from random noise, which is central to escaping from saddle points.\nBy leveraging the proposed AG methods for extracting the negative curvature, we\npresent a new AG algorithm with double loops for non-convex\noptimization~\\footnote{this is in contrast to a single-loop AG algorithm\nproposed in a recent manuscript~\\citep{AGNON}, which directly analyzed the\nNesterov's AG method for non-convex optimization and appeared online on\nNovember 29, 2017. However, we emphasize that our work is an independent work,\nwhich is inspired by our earlier work~\\citep{NEON17} and is based on a\ndifferent novel analysis.}, which converges to second-order stationary point\n$\\x$ such that $\\|\\nabla f(\\x)\\|\\leq \\epsilon$ and $\\nabla^2 f(\\x)\\geq\n-\\sqrt{\\epsilon} I$ with $\\widetilde O(1/\\epsilon^{1.75})$ iteration\ncomplexity, improving that of gradient descent method by a factor of\n$\\epsilon^{-0.25}$ and matching the best iteration complexity of second-order\nHessian-free methods for non-convex optimization.\n",
"title": "NEON+: Accelerated Gradient Methods for Extracting Negative Curvature for Non-Convex Optimization"
}
| null | null | null | null | true | null |
15773
| null |
Default
| null | null |
null |
{
"abstract": " We use Energy Packet Network paradigms to investigate energy distribution\nproblems in a computer system with energy harvesting and storages units. Our\ngoal is to minimize both the overall average response time of jobs at\nworkstations and the total rate of energy lost in the network. Energy is lost\nwhen it arrives at idle workstations which are empty. Energy is also lost in\nstorage leakages. We assume that the total rate of energy harvesting and the\nrate of jobs arriving at workstations are known. We also consider a special\ncase in which the total rate of energy harvesting is sufficiently large so that\nworkstations are less busy. In this case, energy is more likely to be sent to\nan idle workstation. Optimal solutions are obtained which minimize both the\noverall response time and energy loss under the constraint of a fixed energy\nharvesting rate.\n",
"title": "Optimal Energy Distribution with Energy Packet Networks"
}
| null | null | null | null | true | null |
15774
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we prove a refined version of a theorem by Tamagawa and\nMochizuki on isomorphisms between (tame) arithmetic fundamental groups of\nhyperbolic curves over finite fields, where one \"ignores\" the information\nprovided by a \"small\" set of primes.\n",
"title": "A refined version of Grothendieck's anabelian conjecture for hyperbolic curves over finite fields"
}
| null | null | null | null | true | null |
15775
| null |
Default
| null | null |
null |
{
"abstract": " In a recent paper M. Lopez-Suarez, I. Neri, and L. Gammaitoni (LNG) present a\nconcrete realization of the Boolean OR irreversible gate, but contrary to the\nstandard Landauer principle, with an arbitrary small dissipation of energy. A\nPopperian good falsification! In this paper we discuss a theoretical\ndescription of the LNG device which is indeed a 3in/3out self--reversible\nrealization of the involved OR gate, satisfying in this way the Landauer\nprinciple of no dispersion of energy, contrary to the LNG conclusions. The\ndifferent point of view is due to a different interpretation of the two outputs\ncorresponding to the inputs 10 and 01, which are considered by LNG\nindistinguishable so producing a non reversible realization of the standard\n2in/1out gate. On the contrary, always considering these two outputs\nindistinguishable, by a suitable normalization function of the cantilever\nangles, the experimental results obtained by the LNG device coincide with the\nOR connective obtained from the third output of the self-reversible 3in/3out CL\ngate by the Inputs-Ancilla->Garbage-Output procedure. Thus, by the\nself-reversibility this realization is without dissipation of energy according\nto the Landauer principle. Furthermore, using the self-reversible Toffoli gate\nit is possible to obtain from the LNG device the realization of the connective\nAND adopting another normalization function on the cantilever angles. Finally,\nby other suitable normalization procedures on cantilever angles it is possible\nto obtain also the other logic NOR and NAND connectives, and in a more\nsophisticated way the XOR and NXOR connectives in a self-reversible way. All\nthis leads to introduce a universal logic machine consisting of the LNG device\nplus a memory containing all the necessary angle normalization functions to\nproduce in a self-reversible way, by choosing one of these latter, the logic\nconnectives now listed.\n",
"title": "A discussion about LNG Experiment: Irreversible or Reversible Generation of the OR Logic Gate?"
}
| null | null | null | null | true | null |
15776
| null |
Default
| null | null |
null |
{
"abstract": " Let $(\\sigma,\\delta)$ be a quasi derivation of a ring $R$ and $M_R$ a right\n$R$-module. In this paper, we introduce the notion of $(\\sigma,\\delta)$-skew\nMcCoy modules which extends the notion of McCoy modules and $\\sigma$-skew McCoy\nmodules. This concept can be regarded also as a generalization of\n$(\\sigma,\\delta)$-skew Armendariz modules. Some properties of this concept are\nestablished and some connections between $(\\sigma,\\delta)$-skew McCoyness and\n$(\\sigma,\\delta)$-compatible reduced modules are examined. Also, we study the\nproperty $(\\sigma,\\delta)$-skew McCoy of some skew triangular matrix extensions\n$V_n(M,\\sigma)$, for any nonnegative integer $n\\geq 2$. As a consequence, we\nobtain: (1) $M_R$ is $(\\sigma,\\delta)$-skew McCoy if and only if\n$M[x]/M[x](x^n)$ is $(\\overline{\\sigma},\\overline{\\delta})$-skew McCoy, and (2)\n$M_R$ is $\\sigma$-skew McCoy if and only if $M[x;\\sigma]/M[x;\\sigma](x^n)$ is\n$\\overline{\\sigma}$-skew McCoy.\n",
"title": "On $(σ,δ)$-skew McCoy modules"
}
| null | null | null | null | true | null |
15777
| null |
Default
| null | null |
null |
{
"abstract": " The aim of this paper, is to define a bivariate exponentiated generalized\nlinear exponential distribution based on Marshall-Olkin shock model.\nStatistical and reliability properties of this distribution are discussed. This\nincludes quantiles, moments, stress-strength reliability, joint reliability\nfunction, joint reversed (hazard) rates functions and joint mean waiting time\nfunction. Moreover, the hazard rate, the availability and the mean residual\nlifetime functions for a parallel system, are established. One data set is\nanalyzed, and it is observed that, the proposed distribution provides a better\nfit than Marshall-Olkin bivariate exponential, bivariate generalized\nexponential and bivariate generalized linear failure rate distributions.\nSimulation studies are presented to estimate both the relative absolute bias,\nand the relative mean square error for the distribution parameters based on\ncomplete data.\n",
"title": "Bivariate Exponentiated Generalized Linear Exponential Distribution with Applications in Reliability Analysis"
}
| null | null |
[
"Mathematics",
"Statistics"
] | null | true | null |
15778
| null |
Validated
| null | null |
null |
{
"abstract": " Despite its attractive features, Congruent-melted Lithium Niobate (CLN)\nsuffers from Photo-Refractive Damage (PRD). This light-induced refractive-index\nchange hampers the use of CLN when high-power densities are in play, a typical\nregime in integrated optics. The resistance to PRD can be largely improved by\ndoping the lithium-niobate substrates with magnesium oxide. However, the\nfabrication of waveguides on MgO-doped substrates is not as effective as for\nCLN: either the resistance to PRD is strongly reduced by the waveguide\nfabrication process (as it happens in Ti-indiffused waveguides) or the\nnonlinear conversion efficiency is lowered (as it occurs in annealed-proton\nexchange). Here we fabricate, for the first time, waveguides starting from\nMgO-doped substrates using the Soft-Proton Exchange (SPE) technique and we show\nthat this third way represents a promising alternative. We demonstrate that SPE\nallows to produce refractive-index profiles almost identical to those produced\non CLN without reducing the nonlinearity in the substrate. We also prove that\nthe SPE does not affect substantially the resistance to PRD. Since the\nfabrication recipe is identical between CLN and MgO-doped substrates, we\nbelieve that SPE might outperform standard techniques to fabricate robust and\nefficient waveguides for high-intensity-beam confinement.\n",
"title": "Soft-proton exchange on Magnesium-oxide-doped substrates a route toward efficient and power-resistant nonlinear converters"
}
| null | null | null | null | true | null |
15779
| null |
Default
| null | null |
null |
{
"abstract": " Taobao, as the largest online retail platform in the world, provides billions\nof online display advertising impressions for millions of advertisers every\nday. For commercial purposes, the advertisers bid for specific spots and target\ncrowds to compete for business traffic. The platform chooses the most suitable\nads to display in tens of milliseconds. Common pricing methods include cost per\nmille (CPM) and cost per click (CPC). Traditional advertising systems target\ncertain traits of users and ad placements with fixed bids, essentially regarded\nas coarse-grained matching of bid and traffic quality. However, the fixed bids\nset by the advertisers competing for different quality requests cannot fully\noptimize the advertisers' key requirements. Moreover, the platform has to be\nresponsible for the business revenue and user experience. Thus, we proposed a\nbid optimizing strategy called optimized cost per click (OCPC) which\nautomatically adjusts the bid to achieve finer matching of bid and traffic\nquality of page view (PV) request granularity. Our approach optimizes\nadvertisers' demands, platform business revenue and user experience and as a\nwhole improves traffic allocation efficiency. We have validated our approach in\nTaobao display advertising system in production. The online A/B test shows our\nalgorithm yields substantially better results than previous fixed bid manner.\n",
"title": "Optimized Cost per Click in Taobao Display Advertising"
}
| null | null | null | null | true | null |
15780
| null |
Default
| null | null |
null |
{
"abstract": " We consider recursive decoding techniques for RM codes, their subcodes, and\nnewly designed codes. For moderate lengths up to 512, we obtain near-optimum\ndecoding with feasible complexity.\n",
"title": "Recursive constructions and their maximum likelihood decoding"
}
| null | null | null | null | true | null |
15781
| null |
Default
| null | null |
null |
{
"abstract": " We report on the design and performance of a mixed-signal application\nspecific integrated circuit (ASIC) dedicated to avalanche photodiodes (APDs) in\norder to detect hard X-ray emissions in a wide energy band onboard the\nInternational Space Station. To realize wide-band detection from 20 keV to 1\nMeV, we use Ce:GAGG scintillators, each coupled to an APD, with low-noise\nfront-end electronics capable of achieving a minimum energy detection threshold\nof 20 keV. The developed ASIC has the ability to read out 32-channel APD\nsignals using 0.35 $\\mu$m CMOS technology, and an analog amplifier at the input\nstage is designed to suppress the capacitive noise primarily arising from the\nlarge detector capacitance of the APDs. The ASIC achieves a performance of 2099\ne$^{-}$ + 1.5 e$^{-}$/pF at root mean square (RMS) with a wide 300 fC dynamic\nrange. Coupling a reverse-type APD with a Ce:GAGG scintillator, we obtain an\nenergy resolution of 6.7% (FWHM) at 662 keV and a minimum detectable energy of\n20 keV at room temperature (20 $^{\\circ}$C). Furthermore, we examine the\nradiation tolerance for space applications by using a 90 MeV proton beam,\nconfirming that the ASIC is free of single-event effects and can operate\nproperly without serious degradation in analog and digital processing.\n",
"title": "Development of a 32-channel ASIC for an X-ray APD Detector onboard the ISS"
}
| null | null |
[
"Physics"
] | null | true | null |
15782
| null |
Validated
| null | null |
null |
{
"abstract": " This paper provides efficient solutions to maximize profit for commercial\nridesharing services, under a pricing model with detour-based discounts for\npassengers. We propose greedy heuristics for real-time ride matching that offer\ndifferent trade-offs between optimality and speed. Simulations on New York City\n(NYC) taxi trip data show that our heuristics are up to 90% optimal and 10^5\ntimes faster than the (necessarily) exponential-time optimal algorithm.\nCommercial ridesharing service providers generate significant savings by\nmatching multiple ride requests using heuristic methods. The resulting savings\nare typically shared between the service provider (in the form of increased\nprofit) and the ridesharing passengers (in the form of discounts). It is not\nclear a priori how this split should be effected, since higher discounts would\nencourage more ridesharing, thereby increasing total savings, but the fraction\nof savings taken as profit is reduced. We simulate a scenario where the\ndecisions of the passengers to opt for ridesharing depend on the discount\noffered by the service provider. We provide an adaptive learning algorithm\nIDFLA that learns the optimal profit-maximizing discount factor for the\nprovider. An evaluation over NYC data shows that IDFLA, on average, learns the\noptimal discount factor in under 16 iterations.\nFinally, we investigate the impact of imposing a detour-aware routing policy\nbased on sequential individual rationality, a recently proposed concept. Such\nrestricted policies offer a better ride experience, increasing the provider's\nmarket share, but at the cost of decreased average per-ride profit due to the\nreduced number of matched rides. We construct a model that captures these\nopposing effects, wherein simulations based on NYC data show that a 7% increase\nin market share would suffice to offset the decreased average per-ride profit.\n",
"title": "Impact of Detour-Aware Policies on Maximizing Profit in Ridesharing"
}
| null | null | null | null | true | null |
15783
| null |
Default
| null | null |
null |
{
"abstract": " We study the higher gradient integrability of distributional solutions $u$ to\nthe equation $div(\\sigma \\nabla u) = 0$ in dimension two, in the case when the\nessential range of $\\sigma$ consists of only two elliptic matrices, i.e.,\n$\\sigma\\in\\{\\sigma_1, \\sigma_2\\}$ a.e. in $\\Omega$.\nIn [4], for every pair of elliptic matrices $\\sigma_1$ and $\\sigma_2$,\nexponents $p_{\\sigma_1,\\sigma_2}\\in(2,+\\infty)$ and $q_{\\sigma_1,\\sigma_2}\\in\n(1,2)$ have been characterised so that if $u\\in\nW^{1,q_{\\sigma_1,\\sigma_2}}(\\Omega)$ is solution to the elliptic equation then\n$\\nabla u\\in L^{p_{\\sigma_1,\\sigma_2}}_{\\rm weak}(\\Omega)$ and the optimality\nof the upper exponent $p_{\\sigma_1,\\sigma_2}$ has been proved. In this paper we\ncomplement the above result by proving the optimality of the lower exponent\n$q_{\\sigma_1,\\sigma_2}$. Precisely, we show that for every arbitrarily small\n$\\delta$, one can find a particular microgeometry, i.e., an arrangement of the\nsets $\\sigma^{-1}(\\sigma_1)$ and $\\sigma^{-1}(\\sigma_2)$, for which there\nexists a solution $u$ to the corresponding elliptic equation such that $\\nabla\nu \\in L^{q_{\\sigma_1,\\sigma_2}-\\delta}$, but $\\nabla u \\notin\nL^{q_{\\sigma_1,\\sigma_2}}.$ The existence of such optimal microgeometries is\nachieved by convex integration methods, adapting to the present setting the\ngeometric constructions provided in [2] for the isotropic case.\n",
"title": "Optimal lower exponent for the higher gradient integrability of solutions to two-phase elliptic equations in two dimensions"
}
| null | null | null | null | true | null |
15784
| null |
Default
| null | null |
null |
{
"abstract": " Careful analyses of photometric and star count data available for the nine\nputative young clusters identified by Camargo et al. (2015, 2016) at high\nGalactic latitudes reveal that none of the groups contain early-type stars, and\nmost are not significant density enhancements above field level. 2MASS colours\nfor stars in the groups match those of unreddened late-type dwarfs and giants,\nas expected for contamination by (mostly) thin disk objects. A simulation of\none such field using only typical high latitude foreground stars yields a\ncolour-magnitude diagram that is very similar to those constructed by Camargo\net al. (2015, 2016) as evidence for their young groups as well as the means of\nderiving their reddenings and distances. Although some of the fields are\ncoincident with clusters of galaxies, one must conclude that there is no\nevidence that the putative clusters are extremely young stellar groups.\n",
"title": "On the existence of young embedded clusters at high Galactic latitude"
}
| null | null |
[
"Physics"
] | null | true | null |
15785
| null |
Validated
| null | null |
null |
{
"abstract": " The global crisis of 2008 provoked a heightened interest among scientists to\nstudy the phenomenon, its propagation and negative consequences. The process of\nmodelling the spread of a virus is commonly used in epidemiology. Conceptually,\nthe spread of a disease among a population is similar to the contagion process\nin economy. This similarity allows considering the contagion in the world\nfinancial system using the same mathematical model of infection spread that is\noften used in epidemiology. Our research focuses on the dynamic behaviour of\ncontagion spreading in the global financial network. The effect of infection by\na systemic spread of risks in the network of national banking systems of\ncountries is tested. An optimal control problem is then formulated to simulate\na control that may avoid significant financial losses. The results show that\nthe proposed approach describes well the reality of the world economy, and\nemphasizes the importance of international relations between countries on the\nfinancial stability.\n",
"title": "The risk of contagion spreading and its optimal control in the economy"
}
| null | null | null | null | true | null |
15786
| null |
Default
| null | null |
null |
{
"abstract": " Identifying arbitrary topologies of power networks in real time is a\ncomputationally hard problem due to the number of hypotheses that grows\nexponentially with the network size. A new \"Learning-to-Infer\" variational\ninference method is developed for efficient inference of every line status in\nthe network. Optimizing the variational model is transformed to and solved as a\ndiscriminative learning problem based on Monte Carlo samples generated with\npower flow simulations. A major advantage of the developed Learning-to-Infer\nmethod is that the labeled data used for training can be generated in an\narbitrarily large amount fast and at very little cost. As a result, the power\nof offline training is fully exploited to learn very complex classifiers for\neffective real-time topology identification. The proposed methods are evaluated\nin the IEEE 30, 118 and 300 bus systems. Excellent performance in identifying\narbitrary power network topologies in real time is achieved even with\nrelatively simple variational models and a reasonably small amount of data.\n",
"title": "A Learning-to-Infer Method for Real-Time Power Grid Topology Identification"
}
| null | null | null | null | true | null |
15787
| null |
Default
| null | null |
null |
{
"abstract": " Gaussian belief propagation (BP) has been widely used for distributed\ninference in large-scale networks such as the smart grid, sensor networks, and\nsocial networks, where local measurements/observations are scattered over a\nwide geographical area. One particular case is when two neighboring agents\nshare a common observation. For example, to estimate voltage in the direct\ncurrent (DC) power flow model, the current measurement over a power line is\nproportional to the voltage difference between two neighboring buses. When\napplying the Gaussian BP algorithm to this type of problem, the convergence\ncondition remains an open issue. In this paper, we analyze the convergence\nproperties of Gaussian BP for this pairwise linear Gaussian model. We show\nanalytically that the updating information matrix converges at a geometric rate\nto a unique positive definite matrix with arbitrary positive semidefinite\ninitial value and further provide the necessary and sufficient convergence\ncondition for the belief mean vector to the optimal estimate.\n",
"title": "Convergence analysis of belief propagation for pairwise linear Gaussian models"
}
| null | null | null | null | true | null |
15788
| null |
Default
| null | null |
null |
{
"abstract": " We provided an analogue Banach-Alaoglu theorem for Hilbert $H^*$-module. We\nconstruct a $\\Lambda$-weak$^*$ topology on a Hilbert $H^*$-module over a proper\n$H^*$-algebra $\\Lambda$, such that the unit ball is compact with respect to\n$\\Lambda$-weak$^*$ topology.\n",
"title": "Banach-Alaoglu theorem for Hilbert $H^*$-module"
}
| null | null | null | null | true | null |
15789
| null |
Default
| null | null |
null |
{
"abstract": " We consider the problem of enabling robust range estimation of eigenvalue\ndecomposition (EVD) algorithm for a reliable fixed-point design. The simplicity\nof fixed-point circuitry has always been so tempting to implement EVD algo-\nrithms in fixed-point arithmetic. Working towards an effective fixed-point\ndesign, integer bit-width allocation is a significant step which has a crucial\nimpact on accuracy and hardware efficiency. This paper investigates the\nshortcomings of the existing range estimation methods while deriving bounds for\nthe variables of the EVD algorithm. In light of the circumstances, we introduce\na range estimation approach based on vector and matrix norm properties together\nwith a scaling procedure that maintains all the assets of an analytical method.\nThe method could derive robust and tight bounds for the variables of EVD\nalgorithm. The bounds derived using the proposed approach remain same for any\ninput matrix and are also independent of the number of iterations or size of\nthe problem. Some benchmark hyperspectral data sets have been used to evaluate\nthe efficiency of the proposed technique. It was found that by the proposed\nrange estimation approach, all the variables generated during the computation\nof Jacobi EVD is bounded within $\\pm1$.\n",
"title": "An Overflow Free Fixed-point Eigenvalue Decomposition Algorithm: Case Study of Dimensionality Reduction in Hyperspectral Images"
}
| null | null | null | null | true | null |
15790
| null |
Default
| null | null |
null |
{
"abstract": " Incentivized advertising is a new ad format that is gaining popularity in\ndigital mobile advertising. In incentivized advertising, the publisher rewards\nusers for watching an ad. An endemic issue here is adverse selection, where\nreward-seeking users select into incentivized ad placements to obtain rewards.\nAdverse selection reduces the publisher's ad profit as well as poses a\ndifficulty to causal inference of the effectiveness of incentivized\nadvertising. To this end, we develop a treatment effect model that allows and\ncontrols for unobserved adverse selection, and estimate the model using data\nfrom a mobile gaming app that offers both incentivized and non-incentivized\nads. We find that rewarding users to watch an ad has an overall positive effect\non the ad conversion rate. A user is 27% more likely to convert when being\nrewarded to watch an ad. However there is a negative offsetting effect that\nreduces the effectiveness of incentivized ads. Some users are averse to delayed\nrewards, they prefer to collect their rewards immediately after watching the\nincentivized ads, instead of pursuing the content of the ads further. For the\nsubset of users who are averse to delayed rewards, the treatment effect is only\n13%, while it can be as high as 47% for other users.\n",
"title": "Incentivized Advertising: Treatment Effect and Adverse Selection"
}
| null | null | null | null | true | null |
15791
| null |
Default
| null | null |
null |
{
"abstract": " The self-annihilation of dark matter particles with mass in the MeV range can\nproduce gamma rays via prompt or secondary radiation. The annihilation rate for\nsuch light dark matter particles is however tightly constrained by cosmic\nmicrowave background (CMB) data. Here we explore the possibility of discovering\nMeV dark matter annihilation with future MeV gamma-ray telescopes taking into\naccount the latest and future CMB constraints. We study the optimal energy\nwindow as a function of the dominant annihilation final state. We consider both\nthe (conservative) case of the dwarf spheroidal galaxy Draco and the (more\noptimistic) case of the Galactic center. We find that for certain channels,\nincluding those with one or two monochromatic photon(s) and one or two neutral\npion(s), a detectable gamma-ray signal is possible for both targets under\nconsideration, and compatible with CMB constraints. For other annihilation\nchannels, however, including all leptonic annihilation channels and two charged\npions, CMB data rule out any significant signal of dark matter annihilation at\nfuture MeV gamma-ray telescopes from dwarf galaxies, but possibly not for the\nGalactic center.\n",
"title": "Prospects for indirect MeV Dark Matter detection with Gamma Rays in light of Cosmic Microwave Background Constraints"
}
| null | null | null | null | true | null |
15792
| null |
Default
| null | null |
null |
{
"abstract": " We prove the orbifold version of Zvonkine's $r$-ELSV formula in two special\ncases: the case of $r=2$ (complete $3$-cycles) for any genus $g\\geq 0$ and the\ncase of any $r\\geq 1$ for genus $g=0$.\n",
"title": "Special cases of the orbifold version of Zvonkine's $r$-ELSV formula"
}
| null | null | null | null | true | null |
15793
| null |
Default
| null | null |
null |
{
"abstract": " We study connected, locally compact metric spaces with transitive isometry\ngroups. For all $\\epsilon \\in \\mathbb{R}^+$, each such space is\n$(1,\\epsilon)$-quasi-isometric to a Lie group equipped with a left-invariant\nmetric. Further, every metric Lie group is $(1, C)$-quasi-isometric to a\nsolvable Lie group, and every simply connected metric Lie group is $(1,\nC)$-quasi-isometrically homeomorphic to a solvable-by-compact metric Lie group.\nWhile any contractible Lie group may be made isometric to a solvable group,\nonly those that are solvable and of type (R) may be made isometric to a\nnilpotent Lie group, in which case the nilpotent group is the nilshadow of the\ngroup. Finally, we give a complete metric characterisation of metric Lie groups\nfor which there exists an automorphic dilation. These coincide with the metric\nspaces that are locally compact, connected, homogeneous, and admit a metric\ndilation.\n",
"title": "From homogeneous metric spaces to Lie groups"
}
| null | null | null | null | true | null |
15794
| null |
Default
| null | null |
null |
{
"abstract": " We prove an abstract theorem giving a $\\langle t\\rangle^\\epsilon$ bound\n($\\forall \\epsilon>0$) on the growth of the Sobolev norms in linear\nSchrödinger equations of the form $i \\dot \\psi = H_0 \\psi + V(t) \\psi $ when\nthe time $t \\to \\infty$. The abstract theorem is applied to several cases,\nincluding the cases where (i) $H_0$ is the Laplace operator on a Zoll manifold\nand $V(t)$ a pseudodifferential operator of order smaller then 2; (ii) $H_0$ is\nthe (resonant or nonresonant) Harmonic oscillator in $R^d$ and $V(t)$ a\npseudodifferential operator of order smaller then $H_0$ depending in a\nquasiperiodic way on time. The proof is obtained by first conjugating the\nsystem to some normal form in which the perturbation is a smoothing operator\nand then applying the results of \\cite{MaRo}.\n",
"title": "Growth of Sobolev norms for abstract linear Schrödinger Equations"
}
| null | null | null | null | true | null |
15795
| null |
Default
| null | null |
null |
{
"abstract": " User-based Collaborative Filtering (CF) is one of the most popular approaches\nto create recommender systems. This approach is based on finding the most\nrelevant k users from whose rating history we can extract items to recommend.\nCF, however, suffers from data sparsity and the cold-start problem since users\noften rate only a small fraction of available items. One solution is to\nincorporate additional information into the recommendation process such as\nexplicit trust scores that are assigned by users to others or implicit trust\nrelationships that result from social connections between users. Such\nrelationships typically form a very sparse trust network, which can be utilized\nto generate recommendations for users based on people they trust. In our work,\nwe explore the use of a measure from network science, i.e. regular equivalence,\napplied to a trust network to generate a similarity matrix that is used to\nselect the k-nearest neighbors for recommending items. We evaluate our approach\non Epinions and we find that we can outperform related methods for tackling\ncold-start users in terms of recommendation accuracy.\n",
"title": "Trust-Based Collaborative Filtering: Tackling the Cold Start Problem Using Regular Equivalence"
}
| null | null | null | null | true | null |
15796
| null |
Default
| null | null |
null |
{
"abstract": " Direct imaging of exoplanets requires the detection of very faint objects\norbiting close to very bright stars. In this context, the SPICES mission was\nproposed to the European Space Agency for planet characterization at visible\nwavelength. SPICES is a 1.5m space telescope which uses a coronagraph to\nstrongly attenuate the central source. However, small optical aberrations,\nwhich appear even in space telescopes, dramatically decrease coronagraph\nperformance. To reduce these aberrations, we want to estimate, directly on the\ncoronagraphic image, the electric field, and, with the help of a deformable\nmirror, correct the wavefront upstream of the coronagraph. We propose an\ninstrument, the Self-Coherent Camera (SCC) for this purpose. By adding a small\n\"reference hole\" into the Lyot stop, located after the coronagraph, we can\nproduce interferences in the focal plane, using the coherence of the stellar\nlight. We developed algorithms to decode the information contained in these\nFizeau fringes and retrieve an estimation of the field in the focal plane.\nAfter briefly recalling the SCC principle, we will present the results of a\nstudy, based on both experiment and numerical simulation, analyzing the impact\nof the size of the reference hole.\n",
"title": "Experimental parametric study of the self-coherent camera"
}
| null | null |
[
"Physics"
] | null | true | null |
15797
| null |
Validated
| null | null |
null |
{
"abstract": " The rapidly growing number of large network analysis problems has led to the\nemergence of many parallel and distributed graph processing systems---one\nsurvey in 2014 identified over 80. Since then, the landscape has evolved; some\npackages have become inactive while more are being developed. Determining the\nbest approach for a given problem is infeasible for most developers. To enable\neasy, rigorous, and repeatable comparison of the capabilities of such systems,\nwe present an approach and associated software for analyzing the performance\nand scalability of parallel, open-source graph libraries. We demonstrate our\napproach on five graph processing packages: GraphMat, the Graph500, the Graph\nAlgorithm Platform Benchmark Suite, GraphBIG, and PowerGraph using synthetic\nand real-world datasets. We examine previously overlooked aspects of parallel\ngraph processing performance such as phases of execution and energy usage for\nthree algorithms: breadth first search, single source shortest paths, and\nPageRank and compare our results to Graphalytics.\n",
"title": "A Comparison of Parallel Graph Processing Implementations"
}
| null | null | null | null | true | null |
15798
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we prove that the gradient ideal of a Morse polynomial is\nradical. This gives a generic class of polynomials whose gradient ideals are\nradical. As a consequence we reclaim a previous result that the unconstrained\npolynomial optimization problem for Morse polynomials has a finite convergence.\n",
"title": "A note on optimization with Morse polynomials"
}
| null | null | null | null | true | null |
15799
| null |
Default
| null | null |
null |
{
"abstract": " Image instance retrieval is the problem of retrieving images from a database\nwhich contain the same object. Convolutional Neural Network (CNN) based\ndescriptors are becoming the dominant approach for generating {\\it global image\ndescriptors} for the instance retrieval problem. One major drawback of\nCNN-based {\\it global descriptors} is that uncompressed deep neural network\nmodels require hundreds of megabytes of storage making them inconvenient to\ndeploy in mobile applications or in custom hardware. In this work, we study the\nproblem of neural network model compression focusing on the image instance\nretrieval task. We study quantization, coding, pruning and weight sharing\ntechniques for reducing model size for the instance retrieval problem. We\nprovide extensive experimental results on the trade-off between retrieval\nperformance and model size for different types of networks on several data sets\nproviding the most comprehensive study on this topic. We compress models to the\norder of a few MBs: two orders of magnitude smaller than the uncompressed\nmodels while achieving negligible loss in retrieval performance.\n",
"title": "Compression of Deep Neural Networks for Image Instance Retrieval"
}
| null | null |
[
"Computer Science"
] | null | true | null |
15800
| null |
Validated
| null | null |
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