English
Related papers

Related papers: Spectral Characteristic Evolution: A New Algorithm…

200 papers

We present a new pseudo-spectral code for the simulation of evolution systems that are second order in space. We test this code by evolving a non-linear scalar wave equation. These non-linear waves can be stably evolved using very simple…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Wolfgang Tichy

We develop a novel technique through spectral decompositions to study the gravitational perturbations of a black hole, without needing to decouple the linearized field equations into master equations and separate their radial and angular…

General Relativity and Quantum Cosmology · Physics 2023-06-19 Adrian Ka-Wai Chung , Pratik Wagle , Nicolas Yunes

Electrocardiography (ECG) signals can be considered as multi-variable time-series. The state-of-the-art ECG data classification approaches, based on either feature engineering or deep learning techniques, treat separately spectral and time…

Machine Learning · Computer Science 2023-11-10 Che Liu , Sibo Cheng , Weiping Ding , Rossella Arcucci

We report on a new 3D numerical code designed to solve the Einstein equations for general vacuum spacetimes. This code is based on the standard 3+1 approach using cartesian coordinates. We discuss the numerical techniques used in developing…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Peter Anninos , Karen Camarda , Joan Masso , Edward Seidel , Wai-Mo Suen , John Towns

Solving inverse and optimization problems over solutions of nonlinear partial differential equations (PDEs) on complex spatial domains is a long-standing challenge. Here we introduce a method that parameterizes the solution using spectral…

Numerical Analysis · Mathematics 2025-10-30 James V. Roggeveen , Michael P. Brenner

We study the scalar, conformally invariant wave equation on a four-dimensional Minkowski background in spherical symmetry, using a fully pseudospectral numerical scheme. Thereby, our main interest is in a suitable treatment of spatial…

General Relativity and Quantum Cosmology · Physics 2014-04-03 Jörg Frauendiener , Jörg Hennig

Spectral clustering is a key research topic in the field of machine learning and data mining. Most of the existing spectral clustering algorithms are built upon Gaussian Laplacian matrices, which are sensitive to parameters. We propose a…

Machine Learning · Computer Science 2015-10-07 Xiaojun Chang , Feiping Nie , Yi Yang , Heng Huang

We investigate spectral stability of vortex solutions of the Gross-Pitaevskii equation, a mean-field approximation for Bose-Einstein condensates (BEC) in an effectively two-dimensional axisymmetric harmonic trap. We study eigenvalues of the…

Analysis of PDEs · Mathematics 2012-09-17 Richard Kollár , Robert L. Pego

We introduce a novel spectral element method based on the ultraspherical spectral method and the hierarchical Poincar\'{e}-Steklov scheme for solving second-order linear partial differential equations on polygonal domains with unstructured…

Numerical Analysis · Mathematics 2021-05-19 Daniel Fortunato , Nicholas Hale , Alex Townsend

With the example of the spherically symmetric scalar wave equation on Minkowski space-time we demonstrate that a fully pseudospectral scheme (i.e. spectral with respect to both spatial and time directions) can be applied for solving…

General Relativity and Quantum Cosmology · Physics 2010-11-05 Jörg Hennig , Marcus Ansorg

To improve the classification performance in the context of hyperspectral image processing, many works have been developed based on two common strategies, namely the spatial-spectral information integration and the utilization of neural…

Computer Vision and Pattern Recognition · Computer Science 2020-06-24 Yi Liang , Xin Zhao , Alan J. X. Guo , Fei Zhu

This paper proposes a new approach to construct high quality space-filling sample designs. First, we propose a novel technique to quantify the space-filling property and optimally trade-off uniformity and randomness in sample designs in…

We provide a new approach to obtain solutions of certain evolution equations set in a Banach space and equipped with nonlocal boundary conditions. From this approach we derive a family of numerical schemes for the approximation of the…

Numerical Analysis · Mathematics 2024-02-13 Paola Boito , Yuli Eidelman , Luca Gemignani

Ultrafast multidimensional spectroscopies are powerful tools that can access charge and energy flow in complex materials, shifting chemical kinetics, and even many-body interactions in correlated matter. However, current implementations…

Multiple scattering of an electromagnetic wave as it passes through an object is a fundamental problem that limits the performance of current imaging systems. In this paper, we describe a new technique-called Series Expansion with…

Computer Vision and Pattern Recognition · Computer Science 2017-05-12 Hsiou-Yuan Liu , Dehong Liu , Hassan Mansour , Petros T. Boufounos , Laura Waller , Ulugbek S. Kamilov

In this paper, we investigate the stochastic evolution equations (SEEs) driven by $\log$-Whittle-Mat$\acute{{\mathrm{e}}}$rn (W-M) random diffusion coefficient field and $Q$-Wiener multiplicative force noise. First, the well-posedness of…

Numerical Analysis · Mathematics 2022-07-05 X. Qi , M. Azaiez , C. Huang , C. Xu

A matrix representation of the evolution operator associated with a nonlinear stochastic flow with additive noise is used to compute its spectrum. In the weak noise limit a perturbative expansion for the spectrum is formulated in terms of…

We describe a method for initializing characteristic evolutions of the Einstein equations using a linearized solution corresponding to purely outgoing radiation. This allows for a more consistent application of the characteristic (null…

General Relativity and Quantum Cosmology · Physics 2015-03-18 Nigel Bishop , Denis Pollney , Christian Reisswig

The problem of estimating parameters of a deterministic jump or piecewise linear model is considered. A subspace technique referred to as spectral clustering on subspace (SCS) algorithm is proposed to estimate a set of linear model…

Methodology · Statistics 2013-07-02 Liang Li , Wei Dong , Yindong Ji , Lang Tong

A new model for evolving Evolutionary Algorithms (EAs) is proposed in this paper. The model is based on the Multi Expression Programming (MEP) technique. Each MEP chromosome encodes an evolutionary pattern that is repeatedly used for…

Neural and Evolutionary Computing · Computer Science 2021-10-13 Mihai Oltean
‹ Prev 1 8 9 10 Next ›