報(bào)告人：鄭重

報(bào)告題目：On Euler-extrapoated double-step scale splitting method for a class of complex symmetric linear systems

時(shí)間：12月11日（周六）下午2：00

地點(diǎn)：理工樓631

報(bào)告摘要：We propose an Euler-extrapolated double-step scale splitting (EDSS) iteration method for solving a class of complex symmetric linear systems. Under appropriate constraints, we prove that the EDSS method is unconditionally convergent. Furthermore, we illustrate that the spectral radius of the EDSS iteration matrix does not exceed 0.41057 when the argumentθis2π/45and the relaxation parameterαis 0.27614 or 3.62132, respectively. Numerical experiments verify the correctness of the theoretical results and demonstrate the effectiveness of the EDSS method.

報(bào)告人簡介

鄭重，博士，碩士生導(dǎo)師。主要從事數(shù)值代數(shù)及微分方程的數(shù)值算法研究。以第一作者在Applied Mathematics Letters、Journal of Computational and Applied Mathematics、BIT Numerical Mathematics、Journal of Computational Mathematics等期刊上發(fā)表論文10余篇?，F(xiàn)主持國家自然科學(xué)基金青年基金1項(xiàng)，河南省高等學(xué)校重點(diǎn)科研項(xiàng)目1項(xiàng)。2017年獲河南省第四屆本科高校青年教師技能競賽一等獎(jiǎng)。

報(bào)告人：廖麗丹

時(shí)間：12月11日（周六）下午3：00

地點(diǎn)：理工樓631

題目：Preconditioned iterative method for nonsymmetric saddle point linear systems

報(bào)告摘要：In this paper, a new preconditioned iterative method is presented to solve a class of nonsymmetric nonsingular or singular saddle point problems. The implementation of the proposed preconditioned Krylov subspace method avoids solving inverse of Schur complement and only needs to solve one linear sub-system at each step, which implies that it may save considerable costs. Theoretical convergence analysis, including the bounds of eigenvalues and eigenvectors, the degree of the minimal polynomial of the preconditioned matrix, are discussed in details. Moreover, a novel algebraic estimation technique for finding a practical iteration parameter is presented, which is very effective and practical even for large scale problems. At last, some numerical examples are carried, showing that the theoretical results are valid and convincing.

報(bào)告人簡介

廖麗丹，博士。南昌大學(xué)贛江青年學(xué)者。研究方向?yàn)槠⒎址匠虜?shù)值問題及圖像處理問題中的高效數(shù)值代數(shù)算法研究。主持國家級和省部級科研項(xiàng)目各一項(xiàng)，獲批2020年國家留學(xué)基金委面上項(xiàng)目資助，參與國家級項(xiàng)目多項(xiàng)，完成中央高校優(yōu)秀研究生創(chuàng)新項(xiàng)目一項(xiàng)，發(fā)表SCI論文多篇，參編國家級教材2部。獲南昌大學(xué)理學(xué)院“十佳教書育人獎(jiǎng)”，省級一流課程建設(shè)主要參與人。

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2021年12月10日