返回
A NESTED LANCZOS METHOD FOR THE TRUST-REGION SUBPROBLEM
DOI:10.1137/17M1145914.png)
摘要
En 中文
The trust-region subproblem (TRS) minimizes a quadratic f(s) = s(T) Hs/2 + s(T)g over the ellipsoidal constraint parallel to s parallel to(M) <= Delta for a symmetric and positive definite matrix M. For a large scale TRS, a Lanczos-type approach, namely, the generalized Lanczos trust-region (GLTR) method was introduced by Gould, Lucidi, Roma, and Toint [SIAM J. Optim., 9 (1999), pp. 504{525], and extends nicely the classical Lanczos method for the eigenvalue problem to TRS. Basically, GLTR attempts to obtain a feasible approximation in the Krylov subspace K-k(M-1 H, M-1 g) in an efficient way. For an accurate approximation, the dimension k of K-k(M-1 H, M-1 g) is usually modest for a well-conditioned TRS, but can be large for ill-conditioned problems. This causes numerical difficulties in the computational costs, memory requirements, and numerical stability. This paper introduces an efficient nested restarting strategy for GLTR and resolves these numerical troubles. Convergence analysis and numerical testings are carried out to support our improvements upon GLTR.
Keyword:
Lanczos method
Krylov subspace
restarting
nested GMRES
trust-region subproblem
ill-conditioned
AI总结
对已上传原文的论文进行重点信息的提取,主要内容包括:简要概述、研究摘要、背景介绍、关键亮点、图文解析、展望与总结。
期刊
IF:
2.6
论文数:
5.1K
被引数:
1.8W
机构
引用论文
A trust-region approach to the regularization of large-scale discrete forms of ill-posed problems用于不适定问题的大规模离散形式的正则化的信任区域方法

