检索结果-内蒙古大学图书馆

Isotropic Cloak Materials Design Based on the Numerical Optimization Method of the Inverse Medium Problem

Advances in Applied Mathematics and Mechanics 2022年第2期14卷 442-468页

作者： Wei Yang Tiancheng Wang Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational ScienceXiangtan UniversityXiangtanHunan 411105China

In recent years,various kinds of cloak devices were designed by transforma-tion optics,but these cloak metamaterials are anisotropic and difﬁcult to *** this paper,we designed the isotropic cloak metamaterials based on the numeri-cal method of the optimization theory to the inverse medium *** method has universality,and it is not limited by the shape and type of the cloak *** isotropic material is easier to manufacture in practice than anisotropic material.A large number of numerical results show the effectiveness of the method.

关键词： Inverse medium problem isotropic cloak materials ﬁnite element simulations.

来源：评论

学校读者我要写书评

暂无评论

Stochastic SEIR epidemic models with virus mutation and logistic growth of susceptible populations

引用

Mathematics and Computers in simulation 2023年第1期212卷 289-309页

作者： Wang, Qi Xiang, Kainan Zhu, Chunhui Zou, Lang Hunan Key Laboratory for Computation and Simulation in Science and Engineering & Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education & School of Mathematics and Computational Science Xiangtan University Hunan Province Xiangtan City411105 China National Center for Applied Mathematics in Hunan China

This article introduces a kind of stochastic SEIR models containing virus mutation and logistic growth of susceptible populations, whose deterministic versions have a positively invariant set and globally asymptotically stable equilibrium points. For these stochastic SEIR epidemic models, we prove they have a unique global positive solution, and also obtain sufficient conditions respectively for survival and extinction of the infectious disease. Eventually, we validate our theoretical findings using numerical simulations. © 2.2. International Association for Mathematics and Computers in simulation (IMACS)

关键词： Viruses

来源：评论

学校读者我要写书评

暂无评论

Optimal Convergence Rate of q-Maruyama Method for StochasticVolterra Integro-Differential Equations with Riemann-Liouville Fractional Brownian Motion

引用

Advances in Applied Mathematics and Mechanics 2022年第1期14卷 202-217页

作者： Mengjie Wang Xinjie Dai Aiguo Xiao School of Mathematics and Computational Science&Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtanHunan 411105China

This paper mainly considers the optimal convergence analysis of the q-Maruyama method for stochastic Volterra integro-differential equations(SVIDEs)driven by Riemann-Liouville fractional Brownian motion under the global Lipschitz and linear growth ***,based on the contraction mapping principle,we prove the well-posedness of the analytical solutions of the ***,we show that the q-Maruyama method for the SVIDEs can achieve strong first-order *** particular,when the q-Maruyama method degenerates to the explicit Euler-Maruyama method,our result improves the conclusion that the convergence rate is H+1/2.H∈(0,1/2.by Yang et al.,***.,383(2.2.),***,the numerical experiment verifies our theoretical results.

关键词： Stochastic Volterra integro-differential equations Riemann-Liouville fractional Brownian motion well-posedness strong convergence

来源：评论

学校读者我要写书评

暂无评论

Stability and Convergence of the Canonical Euler Splitting Method for Nonlinear Composite Stiff Functional Differential-Algebraic Equations

引用

Advances in Applied Mathematics and Mechanics 2022年第6期14卷 1276-1301页

作者： Hongliang Liu Yameng Zhang Haodong Li Shoufu Li School of Mathematics and Computational Science&Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtanHunan 411105China

A novel canonical Euler splitting method is proposed for nonlinear compositestiff functional differential-algebraic equations, the stability and convergence of themethod is evidenced, theoretical results are further confirmed by some numerical ***, the numerical method and its theories can be applied to specialcases, such as delay differential-algebraic equations and integral differential-algebraicequations.

关键词： Canonical Euler splitting method nonlinear composite stiff functional differentialalgebraic equations stability convergence.

来源：评论

学校读者我要写书评

暂无评论

A Finite Element Variational Multiscale Method for Stationary Incompressible Magnetohydrodynamics Equations

引用

Advances in Applied Mathematics and Mechanics 2023年第5期15卷 1142-1165页

作者： Huayi Huang Yunqing Huang Qili Tang Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of IntelligentComputing&Information Processing of Ministry of EducationSchool of Mathematics and Computational ScienceXiangtan UniversityXiangtanHunan 411105China

In this paper,we propose a variational multiscale method(VMM)for the stationary incompressible magnetohydrodynamics *** method is defined by large-scale spaces for the velocity field and the magnetic field,which aims to solve flows at high Reynolds *** provide a new VMM formulation and prove its stability and ***,some numerical experiments are presented to indicate the optimal convergence of our method.

关键词： Variational multiscale method stationary incompressible magnetohydrodynamics large-scale spaces stability and convergence high Reynolds numbers

来源：评论

学校读者我要写书评

暂无评论

CONVERGENCE ANALYSIS OF SOME FINITE ELEMENT PARALLEL ALGORITHMS FOR THE STATIONARY INCOMPRESSIBLE MHD EQUATIONS

引用

Journal of computational Mathematics 2024年第1期42卷 49-70页

作者： Xiaojing Dong Yinnian He Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing&Information Processing of Ministry of EducationSchool of Mathematics and Computational ScienceXiangtan UniversityXiangtan 411105China Institute of Applied Physics and Computational Mathematics Beijing 100088China School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'an 710049China

By combination of iteration methods with the partition of unity method(PUM),some finite element parallel algorithms for the stationary incompressible magnetohydrodynamics(MHD)with different physical parameters are presented and *** algorithms are highly *** first,a global solution is obtained on a coarse grid for all approaches by one of the iteration *** parallelized residual schemes,local corrected solutions are calculated on finer meshes with overlapping *** subdomains can be achieved flexibly by a class of *** proposed algorithm is proved to be uniformly stable and ***,one numerical example is presented to confirm the theoretical findings.

关键词： Partition of unity method Local and parallel algorithm Finite element method Iteration methods Magnetohydrodynamics

来源：评论

学校读者我要写书评

暂无评论

Multiscale Modeling with Online Correction for Darcy–Forchheimer Flow

引用

Lobachevskii Journal of Mathematics 2024年第11期45卷 5424-5436页

作者： Spiridonov, D.A. Huang, J. Laboratory of Computational Technologies and Artificial Intelligence North-Eastern Federal University Yakutsk 677000 Russian Federation School of Mathematics and Computational Science Xiangtan University National Center for Applied Mathematics in Hunan and Hunan Key Laboratory for Computation and Simulation in Science and Engineering Hunan Xiangtan 411105 China

Abstract: In this research, we present an algorithm of the Online generalized multiscale finite element method (Online GMsFEM) for Darcy–Forchheimer model in fractured media. The mathematical model describes a nonlinear Darcy flow with a high inertial effect and flow speed. The fine grid approximation is carried out by the finite element method (FEM) and to approximate lower dimensional fractures we use a discrete fracture model (DFM). We use a model reduction approach called Online GMsFEM, that is based on local residuals of coarse neighborhoods. The online multiscale basis functions are constructed in each local domain based on residuals. Such online multiscale basis functions make it possible take into account the effects of nonlinear coefficients in the Darcy–Forchheimer equation. We present numerical results in two-dimensional heterogeneous fractured domain. We investigate the accuracy of the method, depending on the influence of nonlinearity. The numerical experiments show that the Online GMsFEM has high accuracy for such nonlinear problems. The accuracy weakly depends on the magnitude of the nonlinear part of the equation. © Pleiades Publishing, Ltd. 2.2..

关键词： Darcy–Forchheimer model discrete fracture model finite element method fractured domain multiscale model reduction nonlinear flow problem Online generalized multiscale finite element method

来源：评论

学校读者我要写书评

暂无评论

An Algebraic Multigrid-Based Physical Factorization Preconditioner for the Multi-Group Radiation Diffusion Equations in Three Dimensions

引用

Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 410-432页

作者： Xiaoqiang Yue Zekai Zhang Xiaowen Xu Shuying Zhai Shi Shu National Center for Applied Mathematics in Hunan Key Laboratory of Intelligent Computing&Information Processing of Ministry of EducationHunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityXiangtan 411105China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100094China School of Mathematical Sciences Huaqiao UniversityQuanzhou 362021China.

The paper investigates the robustness and parallel scaling properties of a novel physical factorization preconditioner with algebraic multigrid subsolves in the iterative solution of a cell-centered finite volume discretization of the threedimensional multi-group radiation diffusion *** key idea is to take advantage of a particular kind of block factorization of the resulting system matrix and approximate the left-hand block matrix selectively spurred by parallel processing *** spectral property of the preconditioned matrix is then *** practical strategy is considered sequentially and in ***,numerical results illustrate the numerical robustness,computational efficiency and parallel strong and weak scalabilities over the real-world structured and unstructured coupled problems,showing its competitiveness with many existing block preconditioners.

关键词： Radiation diffusion equations physical factorization preconditioning algebraic multigrid parallel and distributed computing

来源：评论

学校读者我要写书评

暂无评论

Divergence-Free Virtual Element Method for the Stokes Equations with Damping on Polygonal Meshes

引用

Numerical Mathematics(Theory,Methods and Applications) 2024年第1期17卷 210-242页

作者： Yu Xiong Yanping Chen Jianwei Zhou Qin Liang School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityXiangtan 411105P.R.China School of Mathematics and Statistics Linyi University Linyi 276005P.R.China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this paper,we construct,analyze,and numerically validate a family of divergence-free virtual elements for Stokes equations with nonlinear damping on polygonal *** virtual element method is H1-conforming and exact *** virtue of these properties and the topological degree argument,we rigorously prove the well-posedness of the proposed discrete *** con-vergence analysis is carried out,which imply that the error estimate for the velocity in energy norm does not explicitly depend on the *** experiments on various polygonal meshes validate the accuracy of the theoretical analysis and the asymptotic pressure robustness of the proposed scheme.

关键词： Optimal error estimates divergence-free virtual element nonlinear damping term.

来源：评论

学校读者我要写书评

暂无评论

Piecewise Spectral Collocation Method for Second Order Volterra Integro-Differential Equations with Nonvanishing Delay

引用

Advances in Applied Mathematics and Mechanics 2022年第6期14卷 1333-1356页

作者： Zhenrong Chen Yanping Chen Yunqing Huang School of Mathematical Sciences South China Normal UniversityGuangzhouGuangdong 510631China School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityXiangtanHunan 411105China

In this paper,the piecewise spectral-collocation method is used to solve the second-order Volterra integral differential equation with nonvanishing *** this collocation method,the main discontinuity point of the solution of the equation is used to divide the partitions to overcome the disturbance of the numerical error convergence caused by the main discontinuity of the solution of the *** approximation in the sense of integral is constructed in numerical format,and the convergence of the spectral collocation method in the sense of the L¥and L2.norm is proved by the Dirichlet *** the same time,the error convergence also meets the effect of spectral accuracy *** numerical experimental results are given at the end also verify the correctness of the theoretically proven results.

关键词： Second-order Volterra type integro-differential equation delay function piecewise spectral-collocation method.

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：