SIAM J. Sci. Comput.最新文献_第8页

A Bound-Preserving and Positivity-Preserving Path-Conservative Discontinuous Galerkin Method for Solving Five-Equation Model of Compressible Two-Medium Flows 求解可压缩双介质流五方程模型的保界保正路径保守间断Galerkin方法

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1444497

Jian Cheng, Fan Zhang

引用次数: 3

Newton-Noda Iteration for Computing the Ground States of Nonlinear Schrödinger Equations 计算非线性Schrödinger方程基态的Newton-Noda迭代

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1435793

Changgeng Du, Ching-Sung Liu

引用次数: 3

Parallel-in-time preconditioner for the Sinc-Nyström systems Sinc-Nyström系统的并行实时预调节器

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1462696

Jun Liu, Shulin Wu

引用次数: 0

A Very Easy High-Order Well-Balanced Reconstruction for Hyperbolic Systems with Source Terms 具有源项的双曲型系统的一种非常简单的高阶良好平衡重构

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1429230

C. Berthon, Solène Bulteau, F. Foucher, Meissa M'Baye, Victor Michel-Dansac

{"title":"A Very Easy High-Order Well-Balanced Reconstruction for Hyperbolic Systems with Source Terms","authors":"C. Berthon, Solène Bulteau, F. Foucher, Meissa M'Baye, Victor Michel-Dansac","doi":"10.1137/21m1429230","DOIUrl":"https://doi.org/10.1137/21m1429230","url":null,"abstract":"When adopting high-order finite volume schemes based on MUSCL reconstruction techniques to approximate the weak solutions of hyperbolic systems with source terms, the preservation of the steady states turns out to be very challenging. Indeed, the designed reconstruction must preserve the steady states under consideration in order to get the required well-balancedness property. A priori, to capture such a steady state, one needs to solve some strongly nonlinear equations. Here, we design a very easy correction to high-order finite volume methods. This correction can be applied to any scheme of order greater than or equal to 2, such as a MUSCL-type scheme, and ensures that this scheme exactly preserves the steady solutions. The main discrepancy with usual techniques lies in avoiding the inversion of the nonlinear function that governs the steady solutions. Moreover, for under-determined steady solutions, several nonlinear functions must be considered simultaneously. Since the derived correction only considers the evaluation of the governing nonlinear functions, we are able to deal with under-determined stationary systems. Several numerical experiments illustrate the relevance of the proposed well-balanced correction, as well as its main limitation, namely the fact that it may fail at being both well-balanced and more than second-order accurate for a specific class of initial conditions.","PeriodicalId":21812,"journal":{"name":"SIAM J. Sci. Comput.","volume":"44 1","pages":"2506-"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87982767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

UGKS-Based Implicit Iterative Method for Multiscale Nonequilibrium Flow Simulations 基于ugks的多尺度非平衡流动模拟隐式迭代方法

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1421398

Xiaocong Xu, Yajun Zhu, Chang Liu, K. Xu

引用次数: 1

Robust Rational Approximations of Nonlinear Eigenvalue Problems 非线性特征值问题的鲁棒有理逼近

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/20m1380533

S. Güttel, G. Porzio, F. Tisseur

{"title":"Robust Rational Approximations of Nonlinear Eigenvalue Problems","authors":"S. Güttel, G. Porzio, F. Tisseur","doi":"10.1137/20m1380533","DOIUrl":"https://doi.org/10.1137/20m1380533","url":null,"abstract":". We develop algorithms that construct robust (i.e., reliable for a given tolerance, and scaling independent) rational approximants of matrix-valued functions on a given subset of the complex plane. We consider matrix-valued functions provided in both split form (i.e., as a sum of scalar functions times constant coeﬃcient matrices) and in black box form. We develop a new error analysis and use it for the construction of stopping criteria, one for each form. Our criterion for split forms adds weights chosen relative to the importance of each scalar function, leading to the weighted AAA algorithm, a variant of the set-valued AAA algorithm that can guarantee to return a rational approximant with a user-chosen accuracy. We propose two-phase approaches for black box matrix-valued functions that construct a surrogate AAA approximation in phase one and reﬁne it in phase two, leading to the surrogate AAA algorithm with exact search and the surrogate AAA algorithm with cyclic Leja–Bagby reﬁnement. The stopping criterion for black box matrix-valued functions is updated at each step of phase two to include information from the previous step. When convergence occurs, our two-phase approaches return rational approximants with a user-chosen accuracy. We select problems from the NLEVP collection that represent a variety of matrix-valued functions of diﬀerent sizes and properties and use them to benchmark our algorithms.","PeriodicalId":21812,"journal":{"name":"SIAM J. Sci. Comput.","volume":"32 1","pages":"2439-"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91171129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Active Neuron Least Squares: A Training Method for Multivariate Rectified Neural Networks 主动神经元最小二乘:一种多元校正神经网络的训练方法

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1460764

M. Ainsworth, Yeonjong Shin

引用次数: 3

Approximating Longest Common Subsequence in Linear Time: Beating the $sqrt{{n}}$ Barrier 在线性时间内逼近最长公共子序列:突破$sqrt{{n}}$障碍

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/19m1272068

M. Hajiaghayi, Masoud Seddighin, Saeed Seddighin, Xiaorui Sun

引用次数: 0

Energy Stable and Mass Conservative Numerical Method for Gas Flow in Porous Media with Rock Compressibility 岩石可压缩性多孔介质中气体流动的能量稳定和质量守恒数值方法

SIAM J. Sci. Comput. Pub Date : 2022-08-01 DOI: 10.1137/21m1444461

Jisheng Kou, Xiuhua Wang, S. Du