October 2020 arXiv papers — page 101
Showing 10,001–10,100 of 16,697 papers
Perturbative method to estimate meson masses in the framework of Bethe-Salpeter equation beyond its dominant interaction
hep-phShu-Sheng Xu, Chao Shi
We propose a novel method to calculate the meson mass in the framework of Dyson-Schwinger equation and Bethe-Salpeter equation, once their dominant interactions are identified. The method is based on the perturbation theory of matrix, which is widely used in quantum mechanics. Taking interactions other than the dominant ones as perturbations, we derive the f
Ankur Goswami, Akshata Bhat, Hadar Ohana, Theodoros Rekatsinas
We show that state-of-the-art self-supervised language models can be readily used to extract relations from a corpus without the need to train a fine-tuned extractive head. We introduce RE-Flex, a simple framework that performs constrained cloze completion over pretrained language models to perform unsupervised relation extraction. RE-Flex uses contextual ma
Xingyao Zhang, Linjun Shou, Jian Pei, Ming Gong
The abundant semi-structured data on the Web, such as HTML-based tables and lists, provide commercial search engines a rich information source for question answering (QA). Different from plain text passages in Web documents, Web tables and lists have inherent structures, which carry semantic correlations among various elements in tables and lists. Many exist
Fengqiang Li, Florian Willomitzer, Prasanna Rangarajan, Oliver Cossairt
State-of-the-art time-of-flight (ToF) based 3D sensors suffer from poor lateral and depth resolutions. In this work, we introduce a novel sensor concept that provides ToF-based 3D measurements of real world objects with depth precisions up to 35 micrometers and point cloud densities at the native sensor-resolutions of state-of-the-art CMOS/CCD cameras (up to
Quan Zhang, Yongchao Wang
In this paper, we develop an efficient detector for massive multiple-input multiple-output (MIMO) communication systems via penalty-sharing alternating direction method of multipliers (PS-ADMM). Its main content are as follows: first, we formulate the MIMO detection as a maximum-likelihood optimization problem with bound relaxation constraints. Then, the hig
Effect of spin fluctuations on superconductivity in V and Nb: a first-principles study
cond-mat.supr-conKentaro Tsutsumi, Yuma Hizume, Mitsuaki Kawamura, Ryosuke Akashi
We study the superconductivity in typical $d$-band elemental superconductors V and Nb with the recently developed non-empirical computational scheme based on the density functional theory for superconductors. The effect of ferromagnetic fluctuation (paramagnon) on the superconducting transition temperature ($T_{\rm c}$), which in principle suppress the $s$-w
An adaptive multigrid solver for DPG methods with applications in linear acoustics and electromagnetics
math.NASocratis Petrides, Leszek Demkowicz
We propose an adaptive multigrid preconditioning technology for solving linear systems arising from Discontinuous Petrov-Galerkin (DPG) discretizations. Unlike standard multigrid techniques, this preconditioner involves only trace spaces defined on the mesh skeleton, and it is suitable for adaptive hp-meshes. The key point of the construction is the integrat
Mingzhou Xu, Yunzheng Ding, Yongzheng Zhou
Our purpose is to prove central limit theorem for countable nonhomogeneous Markov chain under the condition of uniform convergence of transition probability matrices for countable nonhomogeneous Markov chain in Cesàro sense. Furthermore, we obtain a corresponding moderate deviation theorem for countable nonhomogeneous Markov chain by Gärtner-Ellis theorem an
Hun Jang, Massimo Porrati
Fermionic terms in a class of locally supersymmetric theories called "liberated supergravity" are nonrenormalizable interactions proportional to inverse powers of the supersymmetry breaking scale and Planck mass. This property defines an intrinsic cutoff for liberated supergravities, which are therefore effective theories valid only below energies th
Observation of solar coronal heating powered by magneto-acoustic oscillations in a moss region
astro-ph.SRParida Hashim, Zhenxiang Hong, Haisheng Ji, Jinhua Shen
In this paper, we report the observed temporal correlation between extreme-violet (EUV) emission and magneto-acoustic oscillations in a EUV moss region, which is the footpoint region only connected by magnetic loops with million-degree plasma. The result is obtained from a detailed multi-wavelength data analysis to the region with the purpose of resolving fi
Bardia Yousefi, Clemente Ibarra Castanedo, Xavier P. V. Maldague
Active and passive thermography are two efficient techniques extensively used to measure heterogeneous thermal patterns leading to subsurface defects for diagnostic evaluations. This study conducts a comparative analysis on low-rank matrix approximation methods in thermography with applications of semi-, convex-, and sparse- non-negative matrix factorization
Yanyan He, Ruosong Mao, Han Cai, Jun-Xiang Zhang
Flat bands play an important role in diffraction-free photonics and attract fundamental interest in many-body physics. Here we report the engineering of flat-band localization of collective excited states of atoms in Creutz superradiance lattices with tunable synthetic gauge fields. Magnitudes and phases of the lattice hopping coefficients can be independent
A. M. Cetto, L. de la Peña, A. Valdés-Hernández
The theories of stochastic quantum mechanics and stochastic electrodynamics bring to light important aspects of the quantum dynamics that are concealed in the standard formalism. Here we take further previous work regarding the connection between the two theories, to exhibit the role of stochasticity and diffusion in the process leading from the originally c
Christopher M. van Bommel
We examine conditions for a pair of strongly cospectral vertices to have pretty good quantum state transfer in terms of minimal polynomials, and provide cases where pretty good state transfer can be ruled out. We also provide new examples of simple, unweighted graphs exhibiting pretty good state transfer. Finally, we consider modifying paths by adding symmet
Google Crowdsourced Speech Corpora and Related Open-Source Resources for Low-Resource Languages and Dialects: An Overview
cs.CLAlena Butryna, Shan-Hui Cathy Chu, Isin Demirsahin, Alexander Gutkin
This paper presents an overview of a program designed to address the growing need for developing freely available speech resources for under-represented languages. At present we have released 38 datasets for building text-to-speech and automatic speech recognition applications for languages and dialects of South and Southeast Asia, Africa, Europe and South A
Peng Peng, Jiugen Wang
It has been challenging to identify ferrograph images with a small dataset and various scales of wear particle. A novel model is proposed in this study to cope with these challenging problems. For the problem of insufficient samples, we first proposed a data augmentation algorithm based on the permutation of image patches. Then, an auxiliary loss function of
On Carleson Measures of Beltrami Coefficients Being Compatible with Infinitely Generated Fuchsian Groups Related to Denjoy Domian
math.CVShengjin Huo
Let $Ω$ be a Carleson-Denjoy domain and $G$ be its covering group. Let $μ$ be a Beltrami coefficient on the unit disk which is compatible with the group $G$. In this paper we show that if $\frac{|μ|^{2}}{1-|z|^{2}}dxdy$ satisfies the Carleson condition on the infinite boundary of the Dirichlet fundamental domain of $G$, then $\frac{|μ|^{2}}{1-|z|^{2}}dxdy$ i
Vokenization: Improving Language Understanding with Contextualized, Visual-Grounded Supervision
cs.CLHao Tan, Mohit Bansal
Humans learn language by listening, speaking, writing, reading, and also, via interaction with the multimodal real world. Existing language pre-training frameworks show the effectiveness of text-only self-supervision while we explore the idea of a visually-supervised language model in this paper. We find that the main reason hindering this exploration is the
Joshua Thorpe, Ruwan Tennakoon, Alireza Bab-Hadiashar
In this paper we propose a real-time and robust solution to large-scale multiple rotation averaging. Until recently, Multiple rotation averaging problem had been solved using conventional iterative optimization algorithms. Such methods employed robust cost functions that were chosen based on assumptions made about the sensor noise and outlier distribution. I
Scaling Hamiltonian Monte Carlo Inference for Bayesian Neural Networks with Symmetric Splitting
stat.MLAdam D. Cobb, Brian Jalaian
Hamiltonian Monte Carlo (HMC) is a Markov chain Monte Carlo (MCMC) approach that exhibits favourable exploration properties in high-dimensional models such as neural networks. Unfortunately, HMC has limited use in large-data regimes and little work has explored suitable approaches that aim to preserve the entire Hamiltonian. In our work, we introduce a new s
John Femi-Oyetoro, Kevin Yao, Evan Hathaway, Yan Jiang
We report that chemical vapor deposition (CVD) grown bilayer and thicker-layered MoS2 are structurally and optically stable under ambient conditions, in comparison to CVD-grown monolayer MoS2 and other transition metal dichalcogenides (TMDs) that have been reported to degrade under the same conditions, hindering their many potential applications. We present
Electron microscopy and spectroscopic study of structural changes, electronic properties and conductivity in annealed Li$_x$CoO$_2$
cond-mat.mtrl-sciHalyna Volkova, Kevin Pachuta, Kyle Crowley, Santosh Kumar Radha
Chemically exfoliated nanoscale few-layer thin Li$_x$CoO$_2$ samples are studied as function of annealing at various temperatures, using transmission electron microscopy (TEM) and Electron Energy Loss Spectroscopies (EELS), probing the O-K, Co-L$_{2,3}$ spectra along with low energy interband transitions. These spectra are compared with first-principles DFT
Flexible mean field variational inference using mixtures of non-overlapping exponential families
math.STJeffrey P. Spence
Sparse models are desirable for many applications across diverse domains as they can perform automatic variable selection, aid interpretability, and provide regularization. When fitting sparse models in a Bayesian framework, however, analytically obtaining a posterior distribution over the parameters of interest is intractable for all but the simplest cases.
Ab-initio study of electronic and magnetic properties of Mn$_2$RuZ/MgO (001) heterojunctions (Z= Al, Ga, Si, Ge)
cond-mat.mtrl-sciTufan Roy, Masahito Tsujikawa, Masafumi Shirai
Using first-principles calculations, we studied Mn$_2$RuZ (Z=Al, Ga, Si, Ge) and their heterojunctions with MgO along (001) direction. All these alloys possess Hg$_2$CuTi-type inverse Heusler alloy structure and ferrimagnetic ground state. Our study reveals the half-metallic electronic structure with highly spin-polarized $Δ_1$ band, which is robust against
Taurus: Lightweight Parallel Logging for In-Memory Database Management Systems (Extended Version)
cs.DBYu Xia, Xiangyao Yu, Andrew Pavlo, Srinivas Devadas
Existing single-stream logging schemes are unsuitable for in-memory database management systems (DBMSs) as the single log is often a performance bottleneck. To overcome this problem, we present Taurus, an efficient parallel logging scheme that uses multiple log streams, and is compatible with both data and command logging. Taurus tracks and encodes transacti
Jesse F. Collis, Selim Olcum, Debadi Chakraborty, Scott R. Manalis
The Navier slip condition describes the motion of a liquid, relative to a neighboring solid surface, with its characteristic Navier slip length being a constitutive property of the solid-liquid interface. Measurement of this slip length is complicated by its small magnitude, expected in the nanometer range based on molecular simulations. Here, we report an e
James Stidham, Michel Pleimling
The late-stage ordering of interacting magnetic skyrmions is studied numerically through extensive Langevin molecular dynamics simulations. Defining skyrmion displacements that change the connectivity of cells obtained in a Voronoi tesselation as events, we investigate event histograms as a function of the time elapsed since preparing the system as well as t
Effects of substrate-surface reconstruction and orientation on spin-valley polarization in MoTe$_2$/EuO
cond-mat.mtrl-sciAo Zhang, Zisheng Gong, Ziming Zhu, Anlian Pan
We investigate the spin-valley polarization in MoTe$_2$ monolayer on (111) and (001) surfaces of ferromagnetic semiconductor EuO based on first-principles calculations. We consider surface reconstructions for EuO(111). We find that there is no direct chemical bonding between the reconstructed EuO(111) and the MoTe$_2$ overlayer, in contrast to the case of th
Jaemin Park
In this paper, we derive some quantitative estimates for uniformly-rotating vortex patches. We prove that if a non-radial simply-connected patch $D$ is uniformly-rotating with small angular velocity $0 < Ω\ll 1$, then the outmost point of the patch must be far from the center of rotation, with distance at least of order $Ω^{-1/2}$. For $m$-fold symmetric sim
Kouyemon Iriye, Daisuke Kishimoto
We characterize two-dimensional Golod complexes combinatorially by vertex-breakability and topologically by the fat-wedge filtration of a polyhedral product. Applying the characterization, we consider a difference between Golodness over fields and rings, which enables us to give a two-dimensional simple Golod complex over any field such that the correspondin
Mechanical Design Improvement of a Passive Device to Assist Eating in People Living with Movement Disorders
cs.ROMichaël Dubé, Thierry Laliberté, Véronique Flamand, François Routhier
Many people living with neurological disorders, such as cerebral palsy, stroke, muscular dystrophy or dystonia experience upper limb impairments (muscle spasticity, loss of selective motor control, muscle weakness or tremors) and have difficulty to eat independently. The general goal of this project is to develop a new device to assist with eating, aimed at
Gabrielle Lemire, Thierry Laliberté, Alexandre Campeau-Lecours
This paper presents the design of a mechanism to help people using mechanical orthoses to extend their legs easily and lock the knee joint of their orthosis. Many people living with spinal cord injury are living with paraplegia and thus need orthoses to be able to stand and walk. Mechanical orthoses are common types of orthopedic devices. This paper proposes
Wasif Husain, Anthony W. Thomas
We consider the possibility of having hybrid stars with a phase transition from hadrons into strange matter at the core of a neutron star in b equilibrium. For the hadron phase equation of state (EoS) the quark-meson coupling model is used, while the MIT bag model is used to describe the strange matter phase. The phase transition is treated using the Gibbs c
Abdul-Hamid Fattah, Assegid Mengistu Flatae, Amr Farrag, Mario Agio
The ultrafast detection of single photons is currently restricted by the limited time resolution (a few picoseconds) of the available single-photon detectors. Optical gates offer a faster time resolution, but so far they have been mostly applied to ensembles of emitters. Here, we demonstrate through a semi-analytical model that the ultrafast time-resolved de
Mauricio Contreras G
In this paper, the Dirac's quantum mechanical interaction picture is applied to option pricing to obtain a solution of the Black-Scholes equation in the presence of a time-dependent arbitrage bubble. In particular, for the case of a call perturbed by a square bubble, an approximate solution (valid up third order in a perturbation series) is given in term
Summer Atkins, Mahya Aghaee, Maia Martcheva, William Hager
In this paper, we will demonstrate how to use a nonlinear polyhedral constrained optimization solver called the Polyhedral Active Set Algorithm (PASA) for solving a general singular control problem. We present methods of discretizing a general optimal control problem that involves the use of the gradient of the Lagrangian for computing the gradient of the co
Lucas J. Fernández-Alcázar, Rodion Kononchuk, Tsampikos Kottos
A thermal current, generated by a temperature gradient between two reservoirs coupled to a carefully designed photonic or (micro-) electromechanical circuit, might induce non-conservative forces that impulse a mechanical degree of freedom to move along a closed trajectory. We show that in the limit of long - but finite - modulation periods, the extracted pow
Guru Guruganesh, Jon Schneider, Joshua Wang
In the classical principal-agent problem, a principal must design a contract to incentivize an agent to perform an action on behalf of the principal. We study the classical principal-agent problem in a setting where the agent can be of one of several types (affecting the outcome of actions they might take). This combines the contract theory phenomena of "
Equal Radiation Frequencies from Different Transitions in the Non-Relativistic Quantum Mechanical Hydrogen Atom
quant-phKim Tuan Do, Trung Phan
Is it possible that two different transitions in the non-relativistic quantum mechanical model of the hydrogen atom give the same frequency? That is, can different energy level transitions in a hydrogen atom have the same photon radiation frequency? This question, which was asked during a Ph.D. oral exam in 1997 at the University of Colorado Boulder, is well
Jishe Feng
Applying Johann Cigler's Hankel determinant formula in terms of the binomial coefficient determinants, which is simplified from Christian Krattenthale's, we get an explicit formula of Hankel determinants for general. As far as I know, those are new results.
Jake Grigsby, Yanjun Qi
Self-supervised learning and data augmentation have significantly reduced the performance gap between state and image-based reinforcement learning agents in continuous control tasks. However, it is still unclear whether current techniques can face a variety of visual conditions required by real-world environments. We propose a challenging benchmark that test
Gregory J. Galloway, Marcus A. Khuri, Eric Woolgar
Is the universe finite or infinite, and what shape does it have? These fundamental questions, of which relatively little is known, are typically studied within the context of the standard model of cosmology where the universe is assumed to be homogeneous and isotropic. Here we address the above questions in highly general cosmological models, with the only a
David Gunawan, Robert Kohn, David Nott
Estimation and prediction in high dimensional multivariate factor stochastic volatility models is an important and active research area because such models allow a parsimonious representation of multivariate stochastic volatility. Bayesian inference for factor stochastic volatility models is usually done by Markov chain Monte Carlo methods, often by particle
Bernardo N. B. de Lima, Sébastien Martineau, Humberto C. Sanna, Daniel Valesin
Let $ \mathbb{L}^{d} = ( \mathbb{Z}^{d},\mathbb{E}^{d} ) $ be the $ d $-dimensional hypercubic lattice. We consider a model of inhomogeneous Bernoulli percolation on $ \mathbb{L}^{d} $ in which every edge inside the $ s $-dimensional hyperplane $ \mathbb{Z}^{s} \times \{ 0 \}^{d-s} $, $ 2 \leq s < d $, is open with probability $ q $ and every other edge is o
Volodimir Begy, Erich Schikuta
This work presents a novel posterior inference method for models with intractable evidence and likelihood functions. Error-guided likelihood-free MCMC, or EG-LF-MCMC in short, has been developed for scientific applications, where a researcher is interested in obtaining approximate posterior densities over model parameters, while avoiding the need for expensi
Alexander Its, Andrei Prokhorov
The Calogero-Painlev\'e systems were introduced in 2001 by K. Takasaki as a natural generalization of the classical Painlev\'e equations to the case of the several Painlev\'e ``particles'' coupled via the Calogero type interactions. In 2014, I. Rumanov discovered the remarkable fact that a particular case of the second Calogero-Painlev\'e II equation describ
Gonçalo Santos, João Martins, André Coelho, Helder Fontes
The ability to operate anywhere, anytime, as well as their capability to hover and carry cargo on board make Unmanned Aerial Vehicles (UAVs) suitable platforms to act as Flying Gateways (FGWs) to the Internet. The problem is the optimal placement of the FGWs within the flying network, such that the Quality of Service (QoS) offered is maximized. The literatur
Optimal minimax bounds for time and ensemble averages for the incompressible Navier-Stokes equations
math.APRicardo M. S. Rosa, Roger M. Temam
Obtaining sharp estimates for quantities involved in a given model is an integral part of the modeling process. For dynamical systems whose orbits display a complicated, perhaps chaotic, behaviour, the aim is usually to estimate time or ensemble averages of given quantities. This is the case, for instance, in turbulent flows. In this work, the aim is to pres
Feng Dai, Andriy Prymak
We prove a new Bernstein type inequality in $L^p$ spaces associated with the tangential derivatives on the boundary of a general compact $C^2$-domain. We give two applications: Marcinkiewicz type inequality for discretization of $L^p$ norm and positive cubature formula. Both results are optimal in the sense that the number of function samples used has the or
Haoyu Wang, Muhao Chen, Hongming Zhang, Dan Roth
Understanding natural language involves recognizing how multiple event mentions structurally and temporally interact with each other. In this process, one can induce event complexes that organize multi-granular events with temporal order and membership relations interweaving among them. Due to the lack of jointly labeled data for these relational phenomena a
Sean McCurdy
In this paper, we study local minimizers of a degenerate version of the Alt-Caffarelli functional. Specifically, we consider local minimizers of the functional $J_{Q}(u, \Omega):= \int_{\Omega} |\nabla u|^2 + Q(x)^2\chi_{\{u>0\}}dx$ where $Q(x) = \text{dist}(x, \Gamma)^{\gamma}$ for $\gamma>0$ and $\Gamma$ a $C^{1, \alpha}$ submanifold of dimension $0 \le k
Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope
astro-ph.GAZohreh Ghaffari, Martin Haas, Marco Chiaberge, S. P. Willner
To properly understand the evolution of high-redshift galaxy clusters, both passive and star-forming galaxies have to be considered. Here we study the clustering environment of 21 radio galaxies and quasars at 1<z<2.5 from the third Cambridge catalog (3C). We use optical and near-infrared Hubble Space Telescope images with a 2' field-of-view, where the f
Jay Fuhrman, Andres F. Clarens, Haewon McJeon, Pralit Patel
China's pledge to reach carbon neutrality before 2060 is an ambitious goal and could provide the world with much-needed leadership on how to limit warming to +1.5C warming above pre-industrial levels by the end of the century. But the pathways that would achieve net zero by 2060 are still unclear, including the role of negative emissions technologies. We
Huai-Yu Wang
We figure out the famous Klein's paradox arising from the reflection problem when a Dirac particle encounters a step potential with infinite width. The key is to piecewise solve Dirac equation in such a way that in the region where the particle's energy E is greater (less) than the potential V, the solution of the positive (negative) energy branch is
Steven Reich, David Mueller, Nicholas Andrews
Modern neural networks do not always produce well-calibrated predictions, even when trained with a proper scoring function such as cross-entropy. In classification settings, simple methods such as isotonic regression or temperature scaling may be used in conjunction with a held-out dataset to calibrate model outputs. However, extending these methods to struc
Mark Green, Phillip Griffiths, Colleen Robles
We propose an analog of the Satake--Baily--Borel compactification and Borel's extension theorem for arbitrary period maps. The proposed analog is constructed as a proper topological completion of the period map. It is conjectured that the construction is projective algebraic, and the conjecture is reduced to a certain extension problem.
Melvyn B. Nathanson
A classical theorem of Kempner states that the sum of the reciprocals of positive integers with missing decimal digits converges. This result is extended to much larger families of "missing digits" sets of positive integers with convergent harmonic series.
Giovanni Dematteis, Yuri V. Lvov
We analyze analytically and numerically the scale invariant stationary solution to the internal wave kinetic equation. Our analysis of the resonant energy transfers shows that the leading order contributions are given (i) by triads with extreme scale separation and (ii) by triads of waves that are quasi-colinear in the horizontal plane. The contributions fro
Bruno Andreotti, Wladimir Toutain, Camille Noûs, Sofia El Rhandour-Essmaili
The course "Phy Ex" was created by Yves Couder in the Paris VII university to teach experimental physics through projects. In this article, we present this teaching method through a particular project that took place in the autumn semester 2019: the ping-pong ball water cannon. In this experiment, a glass containing water and a floating table tennis
Emma Dauterman, Henry Corrigan-Gibbs, David Mazières
We present the design and implementation of SafetyPin, a system for encrypted mobile-device backups. Like existing cloud-based mobile-backup systems, including those of Apple and Google, SafetyPin requires users to remember only a short PIN and defends against brute-force PIN-guessing attacks using hardware security protections. Unlike today's systems, S
P. Ntelis, A. Morris Universitat Bonn - Helmholtz-Institut fur Strahlen und Kernphysik, Bonn, Germany
In this document, we introduce a novel formalism for any field theory and apply it to the effective field theories of large-scale structure. The new formalism is based on functors of actions composing those theories. This new formalism predicts the actionic fields. We discuss our findings in a cosmological gravitology framework. We present these results with
Operator Inference and Physics-Informed Learning of Low-Dimensional Models for Incompressible Flows
math.DSPeter Benner, Pawan Goyal, Jan Heiland, Igor Pontes Duff
Reduced-order modeling has a long tradition in computational fluid dynamics. The ever-increasing significance of data for the synthesis of low-order models is well reflected in the recent successes of data-driven approaches such as Dynamic Mode Decomposition and Operator Inference. With this work, we suggest a new approach to learning structured low-order mo
Non-Bayesian Social Learning on Random Digraphs with Aperiodically Varying Network Connectivity
math.OCRohit Parasnis, Massimo Franceschetti, Behrouz Touri
We study non-Bayesian social learning on random directed graphs and show that under mild connectivity assumptions, all the agents almost surely learn the true state of the world asymptotically in time if the sequence of the associated weighted adjacency matrices belongs to Class $\pstar$ (a broad class of stochastic chains that subsumes uniformly strongly co
Benjamin Landon
We investigate the fluctuations of the free energy of the $2$-spin spherical Sherrington-Kirkpatrick model at critical temperature $\beta_c = 1$. When $\beta = 1$ we find asymptotic Gaussian fluctuations with variance $\frac{1}{6N^2} \log(N)$, confirming in the spherical case a physics prediction for the SK model with Ising spins. We furthermore prove the ex
Zhihang Zhang, Taehoon Han, Kwang Hee Yoo, Jesse Capecelatro
Airborne respiratory diseases such as SARS-CoV-2 (COVID-19) pose significant challenges for public transportation. Several recent outbreaks of SARS-CoV-2 indicate the high risk of transmission among passengers on public buses if special precautions are not taken. This study presents a combined experimental and numerical analysis to identify transmission mech
Santosh Kumar Sankar, Xinyi Huang, Xiang Yang, Jiarong Hong
We employ novel digital Fresnel reflection holography to capture the 3D flows within the viscous sublayer of a smooth-wall turbulent channel flow at Reτ=400. The measurements reveal unsteady and diverse flow patterns in the sublayer including nearly uniform high and low speed flows and strong small-scale (on the order of viscous wall units) spanwise meanderi
Leo Digiosia, Jo Nelson, Haoming Ning, Morgan Weiler
We obtain new sharp obstructions to symplectic embeddings of four-dimensional polydisks $P(a,1)$ into four-dimensional ellipsoids $E(bc,c)$ when $1\le a< 2$ and $b$ is a half-integer. When $1 \leq a < 2-O(b^{-1})$ we demonstrate that $P(a,1)$ symplectically embeds into $E(bc,c)$ if and only if $a+b\le bc$. Our results show that inclusion is optimal and exten
Miquel Ferriol-Galmés, José Suárez-Varela, Pere Barlet-Ros, Albert Cabellos-Aparicio
Recent advances in Machine Learning (ML) have shown a great potential to build data-driven solutions for a plethora of network-related problems. In this context, building fast and accurate network models is essential to achieve functional optimization tools for networking. However, state-of-the-art ML-based techniques for network modelling are not able to pr
Mojtaba Nayyeri, Chengjin Xu, Jens Lehmann, Sahar Vahdati
Knowledge Graph Embeddings (KGEs) have shown promising performance on link prediction tasks by mapping the entities and relations from a knowledge graph into a geometric space (usually a vector space). Ultimately, the plausibility of the predicted links is measured by using a scoring function over the learned embeddings (vectors). Therefore, the capability i
Medial Injury/Dysfunction Induced Granulation Tissue Repair is the Pathogenesis of Atherosclerosis
q-bio.TOXinggang Wang, Aijun Sun, Junbo Ge
Atherosclerosis, a chronic lesion of vascular wall, remains a leading cause of death and loss of life years. Classical hypotheses for atherosclerosis are long-standing mainly to explain atherogenesis. Unfortunately, these hypotheses may not explain the variation in the susceptibility to atherosclerosis. These issues are controversial over the past 150 years.
Tiffany Tianhui Cai, Jonathan Frankle, David J. Schwab, Ari S. Morcos
Self-supervised learning has recently begun to rival supervised learning on computer vision tasks. Many of the recent approaches have been based on contrastive instance discrimination (CID), in which the network is trained to recognize two augmented versions of the same instance (a query and positive) while discriminating against a pool of other instances (n
O. S. Potiienko, I. V. Sharph, T. M. Zelentsova, N. O. Chudak
In this paper we propose a model within which the keeping of quarks inside a proton and the interaction of these quarks with quarks of another hadron can be described simultaneously. The model of a three-particle bispinor field is used for this purpose. Such a field, in comparison with the usual one-particle field, is considered not on Minkowski space, but o
Cancellation of vector bundles of rank $3$ with trivial Chern classes on smooth affine fourfolds
math.AGTariq Syed
If $n \equiv 0,1~mod~4$, we prove a sum formula $V_{θ_{0}} (a_{0},a_{R}^{n}) = n \cdot V_{θ_{0}} (a_{0},a_{R})$ for the generalized Vaserstein symbol whenever $R$ is a smooth affine algebra over a perfect field $k$ with $char(k) \neq 2$ such that $-1 \in {k^{\times}}^{2}$. This enables us to generalize a result of Fasel-Rao-Swan on transformations of unimodu
N. R. Beysengulov, J. R. Lane, J. M. Kitzman, K. Nasyedkin
We report on low-temperature noise measurements of a single electron transistor (SET) immersed in superfluid $^4$He. The device acts as a charge sensitive electrometer able to detect the fluctuations of charged defects in close proximity to the SET. In particular, we measure telegraph switching of the electric current through the device originating from a st
Ezio Bartocci, Roderick Bloem, Benedikt Maderbacher, Niveditha Manjunath
Ensuring correctness of cyber-physical systems (CPS) is an extremely challenging task that is in practice often addressed with simulation based testing. Formal specification languages, such as Signal Temporal Logic (STL), are used to mathematically express CPS requirements and thus render the simulation activity more systematic and principled. We propose a n
Bojana Femić
This is a first of a series of two papers. Our motive is to tackle the question raised in Böhm's "The Gray Monoidal Product of Double Categories" from Applied Categorical Structures: which would be an alternative notion to intercategories of Grandis and Paré, so that monoids in Böhm's monoidal category $Dbl$ of strict double categories and do
Tariq Syed
For a smooth affine algebra $R$ of dimension $d \geq 3$ over a field $k$ and an invertible alternating matrix $\chi$ of rank $2n$, the group $Sp(\chi)$ of invertible matrices of rank $2n$ over $R$ which are symplectic with respect to $\chi$ acts on the right on the set $Um_{2n}(R)$ of unimodular rows of length $2n$ over $R$. In this paper, we prove that $Sp(
Qun Liu, Matthew Shreve, Raja Bala
Although data is abundant, data labeling is expensive. Semi-supervised learning methods combine a few labeled samples with a large corpus of unlabeled data to effectively train models. This paper introduces our proposed method LiDAM, a semi-supervised learning approach rooted in both domain adaptation and self-paced learning. LiDAM first performs localized d
Xiangdong Ji, Yizhuang Liu, Ismail Zahed
We study the mass/energy structure of the bound state of hadrons in two-dimensional quantum chromodynamics in the large number of color limit (t' Hooft model). We analyze separately the contributions from the traceless and trace part of the energy-momentum tensor, and show that the masses are related to the matrix elements of the scalar charge and Coulom
The Impact of Damping in Second-Order Dynamical Systems with Applications to Power Grid Stability
math.DSAmin Gholami, X. Andy Sun
We consider a broad class of second-order dynamical systems and study the impact of damping as a system parameter on the stability, hyperbolicity, and bifurcation in such systems. We prove a monotonic effect of damping on the hyperbolicity of the equilibrium points of the corresponding first-order system. This provides a rigorous formulation and theoretical
Robin Fuchs, Denys Pommeret, Cinzia Viroli
Clustering mixed data presents numerous challenges inherent to the very heterogeneous nature of the variables. A clustering algorithm should be able, despite of this heterogeneity, to extract discriminant pieces of information from the variables in order to design groups. In this work we introduce a multilayer architecture model-based clustering method calle
Zain H. Saleem, Teague Tomesh, Bilal Tariq, Martin Suchara
We study the costs and benefits of different quantum approaches to finding approximate solutions of constrained combinatorial optimization problems with a focus on Maximum Independent Set. In the Lagrange multiplier approach we analyze the dependence of the output on graph density and circuit depth. The Quantum Alternating Ansatz Approach is then analyzed an
Jin Won Kim, Amirhossein Taghvaei, Yongxin Chen, Prashant G. Mehta
The purpose of this paper is to describe the feedback particle filter algorithm for problems where there are a large number ($M$) of non-interacting agents (targets) with a large number ($M$) of non-agent specific observations (measurements) that originate from these agents. In its basic form, the problem is characterized by data association uncertainty wher
Sheng Wang, Yuan Sun, Zhifeng Bao
This paper presents a thorough evaluation of the existing methods that accelerate Lloyd's algorithm for fast k-means clustering. To do so, we analyze the pruning mechanisms of existing methods, and summarize their common pipeline into a unified evaluation framework UniK. UniK embraces a class of well-known methods and enables a fine-grained performance b
Enriched Galerkin Discretization for Modeling Poroelasticity and Permeability Alteration in Heterogeneous Porous Media
cs.CET. Kadeethum, H. M. Nick, S. Lee, F. Ballarin
Accurate simulation of the coupled fluid flow and solid deformation in porous media is challenging, especially when the media permeability and storativity are heterogeneous. We apply the enriched Galerkin (EG) finite element method for the Biot's system. Block structure used to compose the enriched space and linearization and iterative schemes employed to so
Matthew Hutchinson, Vijay Gadepally
Many believe that the successes of deep learning on image understanding problems can be replicated in the realm of video understanding. However, due to the scale and temporal nature of video, the span of video understanding problems and the set of proposed deep learning solutions is arguably wider and more diverse than those of their 2D image siblings. Findi
J. Leo Kim, Ghazal Geshnizjani
It has been recently shown that a cosmological bounce model based on Cuscuton gravity does not have any ghosts or curvature instabilities. We explore whether Cuscuton bounce can provide an alternative to inflation for generating near scale-invariant scalar perturbations. While a single field Cuscuton bounce generically produces a strongly blue power spectrum
Steven Finch
Fix a positive integer $N$. Select an additive composition $ξ$ of $N$ uniformly out of $2^{N-1}$ possibilities. The interplay between the number of parts in $ξ$ and the maximum part in $ξ$ is our focus. It is not surprising that correlations $ρ(N)$ between these quantities are negative; we earlier gave inconclusive evidence that $\lim_{N \to \infty} ρ(N)$ is
Guy Kornowski, Ohad Shamir
In this note, we consider the complexity of optimizing a highly smooth (Lipschitz $k$-th order derivative) and strongly convex function, via calls to a $k$-th order oracle which returns the value and first $k$ derivatives of the function at a given point, and where the dimension is unrestricted. Extending the techniques introduced in Arjevani et al. [2019],
Oliver Davis Johns
Detailed study of the energy and momentum carried by the electromagnetic field can be a source of clues to possible new physics underlying the Maxwell Equations. But such study has been impeded by expressions for the parameters of the electromagnetic energy flow that are inconsistent with the transformation rules of special relativity. This paper begins by c
Gathika Ratnayaka, Thushari Atapattu, Mahen Herath, Georgia Zhang
Cyberbullying is a prevalent social problem that inflicts detrimental consequences to the health and safety of victims such as psychological distress, anti-social behaviour, and suicide. The automation of cyberbullying detection is a recent but widely researched problem, with current research having a strong focus on a binary classification of bullying versu
Matthew Fickus, Joseph W. Iverson, John Jasper, Emily J. King
An equiangular tight frame (ETF) is a sequence of vectors in a Hilbert space that achieves equality in the Welch bound and so has minimal coherence. More generally, an equichordal tight fusion frame (ECTFF) is a sequence of equi-dimensional subspaces of a Hilbert space that achieves equality in Conway, Hardin and Sloane's simplex bound. Every ECTFF is a
Nicholas Kuechel, Marcus Teter, Andrew C. Liebmann, Sachiko Tsuruta
We do not present the discovery of strong nearly coherent oscillations (NCOs) at 890.44 Hz for the low mass X-ray binary MXB 1659-298. We find that what we are detecting is dead time in the NuSTAR detectors. Instead consider this paper as further evidence for why standard timing methods should not be used with NuSTAR data.
Type 0 $\mathbb{Z}_2\times \mathbb{Z}_2$ Heterotic String Orbifolds and Misaligned Supersymmetry
hep-thAlon E. Faraggi, Viktor G. Matyas, Benjamin Percival
The $\mathbb{Z}_2\times \mathbb{Z}_2$ heterotic string orbifold yielded a large space of phenomenological three generation models and serves as a testing ground to explore how the Standard Model of particle physics may be incorporated in a theory of quantum gravity. In this paper we explore the existence of type 0 models in this class of string compactificat
Rodrigo S. Gonçalves, Gabriela C. Carvalho, Uendert Andrade, Carlos A. P. Bengaly
We report measurements of the scale of cosmic homogeneity ($r_{h}$) using the recently released quasar sample of the sixteenth data release of the Sloan Digital Sky Survey (SDSS-IV DR16). We perform our analysis in 2 redshift bins lying in the redshift interval $2.2 < z < 3.2$ by means of the fractal dimension $D_2$. By adopting the usual assumption that $r_
Julia Liebert, Christian Schilling
One-particle reduced density matrix functional theory would potentially be the ideal approach for describing Bose-Einstein condensates. It namely replaces the macroscopically complex wavefunction by the simple one-particle reduced density matrix, therefore provides direct access to the degree of condensation and still recovers quantum correlations in an exac
Ming Lei, Sinisa Coh
We find unusually large cross-polarized (and anti-symmetric) Raman signature of A$_{\rm g}$ phonon mode in CrI$_3$, in agreement with experiments. The signal is present only when the following three effects are considered in concert: ferromagnetism on Cr atoms, spin-orbit interaction, and resonant effects. Somewhat surprisingly, we find that the relevant spi
Uddipan Banik, Frank C. van den Bosch
Impulsive encounters between astrophysical objects are usually treated using the distant tide approximation (DTA) for which the impact parameter, $b$, is assumed to be significantly larger than the characteristic radii of the subject, $r_{\mathrm{S}}$, and the perturber, $r_{\mathrm{P}}$. The perturber potential is then expanded as a multipole series and tru
Jialu Zhang, Yitan Wang, Mark Santolucito, Ruzica Piskac
The decision tree is one of the most popular and classical machine learning models from the 1980s. However, in many practical applications, decision trees tend to generate decision paths with excessive depth. Long decision paths often cause overfitting problems, and make models difficult to interpret. With longer decision paths, inference is also more likely
Interferometric geometry from symmetry-broken Uhlmann gauge group with applications to topological phase transitions
quant-phHector Silva, Bruno Mera, Nikola Paunković
We provide a natural generalization of a Riemannian structure, i.e., a metric, recently introduced by Sjöqvist for the space of non degenerate density matrices, to the degenerate case, i.e., the case in which the eigenspaces have dimension greater than or equal to 1. We present a physical interpretation of the metric in terms of an interferometric measuremen