November 2018 arXiv papers — page 131
Showing 13,001–13,020 of 13,020 papers
Sarah Burke-Spolaor
We review the potential information that can be gleaned from multi-wavelength and multi-messenger detections of Fast Radio Bursts (FRBs). The primary function of such detections, following FRB localization, will be to reveal the progenitors of FRB events. However, these observations serve a more basic function in host galaxy identification, subsequent redshi
Jing-Yan Xu, Yang Dong, Shao-Chun Zhang, Yu Zheng
The sensitivity of a practical quantum magnetometer is challenged by both inhomogeneous coupling between sensors and environment and errors in quantum control. Based on the physical criteria of modern quantum sensing, we present a robust and effective composite-pulse for high fidelity operation against inhomogeneous broadening of sensor and control errors vi
W. J. M. Kort-Kamp, F. J. Culchac, Rodrigo B. Capaz, Felipe A. Pinheiro
The formation of a superstructure - with a related Moiré pattern - plays a crucial role in the extraordinary optical and electronic properties of twisted bilayer graphene, including the recently observed unconventional superconductivity. Here we put forward a novel, interdisciplinary approach to determine the Moiré angle in twisted bilayer graphene based on
Inversion-induced orbital and exchange disorders in antiferromagnetic A-site spinel CoAl2O4
cond-mat.str-elTakashi Naka, Hiroaki Mamiya, Kanji Takehana, Naohito Tsujii
The inversion and volume effects on magnetism in a spinel-type magnetically frustrated compound, CoAl2O4, and its gallium-substituted system, CoAl2-xGaxO4, were investigated. Magnetically frustrated Co2+ with spin S = 3/2 on the tetrahedral site formed a diamond lattice in CoAl2O4 located in the vicinity of the magnetic phase boundary between Neel and spin-s
Haojie Pan, Junpei Zhou, Zhou Zhao, Yan Liu
We first propose a new task named Dialogue Description (Dial2Desc). Unlike other existing dialogue summarization tasks such as meeting summarization, we do not maintain the natural flow of a conversation but describe an object or an action of what people are talking about. The Dial2Desc system takes a dialogue text as input, then outputs a concise descriptio
Changguang Dong, Adam Kanigowski
We study joining rigidity in the class of von Neumann flows with one singularity. They are given by a smooth vector field $\mathcal{X}$ on $\mathbb T^2\setminus \{a\}$, where $\mathcal{X}$ is not defined at $a\in \mathbb T^2$. It follows that the phase space can be decomposed into a (topological disc) $D_\mathcal{X}$ and an ergodic component $E_\mathcal{X}=\
Vivek Sivaraman Narayanaswamy, Jayaraman J. Thiagarajan, Huan Song, Andreas Spanias
State-of-the-art speaker diarization systems utilize knowledge from external data, in the form of a pre-trained distance metric, to effectively determine relative speaker identities to unseen data. However, much of recent focus has been on choosing the appropriate feature extractor, ranging from pre-trained $i-$vectors to representations learned via differen
Shaozhu Xiao, Fangdi Wen, Xiaoran Liu, M. Kareev
Almost all oxide two-dimensional electron gases are formed in SrTiO$_3$-based heterostructures and the study of non-SrTiO$_3$ systems is extremely rare. Here, we report the realization of a two-dimensional electron gas in a CaTiO$_3$-based heterostructure, CaTiO$_3$/LaTiO$_3$, grown epitaxially layer-by-layer on a NdGaO$_3$ (110) substrate via pulsed laser d
Robust switching of superposition-states via a coherent double stimulated Raman adiabatic passage
physics.atom-phLuyao Yan, Dandan Ma, Dongmin Yu, Jing Qian
Coherent manipulation of quantum states is of crucial importance in accurate control of a quantum system. A fundamental goal is coherently transferring the population of a desired state with near-unit fidelity. For this propose, we theoretically demonstrate a novel coherent double-stimulated Raman adiabatic passage (STIRAP) in a three-level $Λ$-type system f
Julie Poullet, Axel Parmentier
Ground staff agents of airlines operate many jobs at airports such as passengers check-in, planes cleaning, etc. Shift planning aims at building the sequences of jobs operated by ground staff agents, and have been widely studied given its impact on operating costs. As these jobs are closely related to flights arrivals and departures, flights delays disrupt g
Panagiotis Kasnesis, Charalampos Z. Patrikakis, Iakovos S. Venieris
Human Activity Recognition (HAR) based on motion sensors has drawn a lot of attention over the last few years, since perceiving the human status enables context-aware applications to adapt their services on users' needs. However, motion sensor fusion and feature extraction have not reached their full potentials, remaining still an open issue. In this pap
Anna Aboud, Emelie Curl, Steven N. Harding, M. Vaughan
The Kaczmarz algorithm is an iterative method for solving a system of linear equations. It can be extended so as to reconstruct a vector $x$ in a (separable) Hilbert space from the inner-products $\{\langle x, ϕ_{n} \rangle\}$. The Kaczmarz algorithms defines a sequence of approximations from the sequence $\{\langle x, ϕ_{n} \rangle\}$; these approximations
Shane Barratt, Stephen Boyd
An extended quadratic function is a quadratic function plus the indicator function of an affine set, that is, a quadratic function with embedded linear equality constraints. We show that, under some technical conditions, random convex extended quadratic functions are closed under addition, composition with an affine function, expectation, and partial minimiz
Abbey J. Neer, Veronika A. Fischer, Michelle Zheng, Nicole R. Spence
Here we present a comparative study of the magnetic and crystal chemical properties of two Co2+ containing garnets, NaCa2Co2V3O12 and CaY2Co2Ge3O12. Both phases exhibit the onset of antiferromagnetic order at 8K and 6K respectively, as well as field-induced transitions in their magnetization at 1T and around 11 T. We find these field-dependent transitions co
Florian A. Driessen, Jon O. Sundqvist, Gregg A. Wade
A small subset of Galactic O-stars possess surface magnetic fields that alter the outflowing stellar wind by magnetically confining it. Key to the magnetic confinement is that it induces rotational modulation of spectral lines over the full EM domain; this allows us to infer basic quantities, e.g., mass-loss rate and magnetic geometry. Here, we present an em
Minqiang Xu, Hailong Guo, Qingsong Zou
In this paper, we propose a novel recovery based finite element method for the Cahn-Hilliard equation. One distinguishing feature of the method is that we discretize the fourth-order differential operator in a standard $C^0$ linear finite elements space. Precisely, we first transform the fourth-order Cahn-Hilliard equation to its variational formulation in w
Bin Shi, Simon S. Du, Michael I. Jordan, Weijie J. Su
Gradient-based optimization algorithms can be studied from the perspective of limiting ordinary differential equations (ODEs). Motivated by the fact that existing ODEs do not distinguish between two fundamentally different algorithms---Nesterov's accelerated gradient method for strongly convex functions (NAG-SC) and Polyak's heavy-ball method---we st
A limited-memory block bi-diagonal Toeplitz preconditioner for block lower triangular Toeplitz system from time-space fractional diffusion equation
math.NAYong-Liang Zhao, Pei-Yong Zhu, Xian-Ming Gu, Xi-Le Zhao
A block lower triangular Toeplitz system arising from time-space fractional diffusion equation is discussed. For efficient solutions of such the linear system, the preconditioned biconjugate gradient stabilized method and flexible general minimal residual method are exploited. The main contribution of this paper has two aspects: (i) A block bi-diagonal Toepl
Pooya Monshizadeh, Nima Monshizadeh, Claudio De Persis, Arjan van der Schaft
Output impedances are inherent elements of power sources in the electrical grids. In this paper, we give an answer to the following question: What is the effect of output impedances on the inductivity of the power network? To address this question, we propose a measure to evaluate the inductivity of a power grid, and we compute this measure for various types
Inexact Arnoldi residual estimates and decay properties for functions of non-Hermitian matrices
math.NAStefano Pozza, Valeria Simoncini
We derive a priori residual-type bounds for the Arnoldi approximation of a matrix function and a strategy for setting the iteration accuracies in the inexact Arnoldi approximation of matrix functions. Such results are based on the decay behavior of the entries of functions of banded matrices. Specifically, we will use a priori decay bounds for the entries of