报告题目1：A variant of PMHSS iteration method for a class of complex symmetric indefinite linear systems

报告人：郑重 博士

报告时间：5月14日下午15：30开始

报告地点：数学与统计学院503教室

报告摘要：We propose a variant of PMHSS iteration method for solving and preconditioning a class of complex symmetric indefinite linear systems. The unconditional convergence theory of this iteration method is proved, and the choice of quasi-optimal parameter is also discussed. The explicit expressions for the eigenvalues and eigenvectors of the corresponding preconditioned matrix are derived. In addition, theoretical analyses show that all eigenvalues are linearly distributed in the unit circle under suitable conditions. Numerical experiments are reported to illustrate the effectiveness and robustness of the proposed method.

报告人简介：郑重，博士，副教授，2016年获兰州大学计算数学博士学位，主要从事数值代数及微分方程的数值算法研究。在国内外学术刊物发表论文10余篇，主持完成国家自然科学基金青年项目1项，河南省高等学校重点科研项目1项。

报告题目2：A C_0 nonconforming element over quadrilateral meshes for the fourth-order elliptic singular perturbation problem

报告人：包园 博士

报告时间：2024年5月 14 日下午15：30开始

报告地点：数学与统计学院503教室

报告摘要： In this talk, a C_0 nonconforming element on quadrilateral meshes is constructed. It is shown that the nonconforming finite element has fewer degrees of freedom without affecting convergence rates. The well-posed proof and convergence analyses are exhibited. The local basis functions of this element can be expressed explicitly by a reference quadrilateral rather than by solving a linear system. Numerical simulations are also carried out to illustrate our theoretical results.

报告人简介：包园，博士，2020年获大连理工大学计算数学博士学位，主要从事有限元和神经网络计算领域的研究，在国内外学术期刊发表学术论文7篇。