In this paper, we further generalize the technique for constructing the normal （or pos- itive definite） and skew-Hermitian splitting iteration method for solving large sparse non- Hermitian positive definite system ...In this paper, we further generalize the technique for constructing the normal （or pos- itive definite） and skew-Hermitian splitting iteration method for solving large sparse non- Hermitian positive definite system of linear equations. By introducing a new splitting, we establish a class of efficient iteration methods, called positive definite and semi-definite splitting （PPS） methods, and prove that the sequence produced by the PPS method con- verges unconditionally to the unique solution of the system. Moreover, we propose two kinds of typical practical choices of the PPS method and study the upper bound of the spectral radius of the iteration matrix. In addition, we show the optimal parameters such that the spectral radius achieves the minimum under certain conditions. Finally, some numerical examples are given to demonstrate the effectiveness of the considered methods.展开更多
We establish the convergence theories of the symmetric relaxation methods for the system of linear equations with symmetric positive definite coefficient matrix, and more generally, those of the unsymmetric relaxation...We establish the convergence theories of the symmetric relaxation methods for the system of linear equations with symmetric positive definite coefficient matrix, and more generally, those of the unsymmetric relaxation methods for the system of linear equations with positive definite matrix.展开更多
A class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The conv...A class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The convergence properties of these methods are discussed in depth, and the best possible choices of the parameters involved in the new methods are investigated in detail. Numerical computations show that the new methods are more efficient and robust than both classical relaxation methods and classical conjugate direction methods.展开更多
对大型稀疏的非Hermite正定线性代数方程组,运用正规和反Hermite分裂(normal and skew-Hermitian splitting,NSS)迭代技巧,提出了一种两参数预处理NSS迭代法,它实际上是预处理NSS方法的推广.理论分析表明,新方法收敛于线性方程组的唯一...对大型稀疏的非Hermite正定线性代数方程组,运用正规和反Hermite分裂(normal and skew-Hermitian splitting,NSS)迭代技巧,提出了一种两参数预处理NSS迭代法,它实际上是预处理NSS方法的推广.理论分析表明,新方法收敛于线性方程组的唯一解.进一步地,推导了出现于新方法中的两个参数的最优选取,计算了对应的迭代谱的上界的最小值.新方法的实际实施中,还将不完全LU分解和增量未知元选做了两类预处理子.数值结果对所给方法的收敛性理论和有效性予以了证实.展开更多
在科学计算及工程应用中经常遇到复对称线性系统问题,近年来对一种特殊类型的复对称线性系统的研究已成为一个热点.基于白中治等的PMHSS方法(Bai Z Z,Benzi M,Chen F,Wang Z Q.Preconditioned MHSS iteration methods for a class of bl...在科学计算及工程应用中经常遇到复对称线性系统问题,近年来对一种特殊类型的复对称线性系统的研究已成为一个热点.基于白中治等的PMHSS方法(Bai Z Z,Benzi M,Chen F,Wang Z Q.Preconditioned MHSS iteration methods for a class of block twoby-two linear systems with applications to distributed control problems.IMA J Numer Anal,2013,33:343-369),提出一类新的PMHSS迭代法用于求解这种特殊形式的复对称线性系统,给出新方法的收敛性理论以及最优参数的表达式,最后用数值例子展示了新方法的有效性.展开更多
文摘In this paper, we further generalize the technique for constructing the normal （or pos- itive definite） and skew-Hermitian splitting iteration method for solving large sparse non- Hermitian positive definite system of linear equations. By introducing a new splitting, we establish a class of efficient iteration methods, called positive definite and semi-definite splitting （PPS） methods, and prove that the sequence produced by the PPS method con- verges unconditionally to the unique solution of the system. Moreover, we propose two kinds of typical practical choices of the PPS method and study the upper bound of the spectral radius of the iteration matrix. In addition, we show the optimal parameters such that the spectral radius achieves the minimum under certain conditions. Finally, some numerical examples are given to demonstrate the effectiveness of the considered methods.
文摘We establish the convergence theories of the symmetric relaxation methods for the system of linear equations with symmetric positive definite coefficient matrix, and more generally, those of the unsymmetric relaxation methods for the system of linear equations with positive definite matrix.
基金Subsidized by The Special Funds For Major State Basic Research Projects G1999032803.
文摘A class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The convergence properties of these methods are discussed in depth, and the best possible choices of the parameters involved in the new methods are investigated in detail. Numerical computations show that the new methods are more efficient and robust than both classical relaxation methods and classical conjugate direction methods.
基金Project supported by the National Basic Research Program of China(973 Program,2011CB706903)the Natural Science Foundation of Jilin Province of China(201115222)
文摘对大型稀疏的非Hermite正定线性代数方程组,运用正规和反Hermite分裂(normal and skew-Hermitian splitting,NSS)迭代技巧,提出了一种两参数预处理NSS迭代法,它实际上是预处理NSS方法的推广.理论分析表明,新方法收敛于线性方程组的唯一解.进一步地,推导了出现于新方法中的两个参数的最优选取,计算了对应的迭代谱的上界的最小值.新方法的实际实施中,还将不完全LU分解和增量未知元选做了两类预处理子.数值结果对所给方法的收敛性理论和有效性予以了证实.
基金supported by the National Natural Science Foundation of China(11371275,201601D011004)
文摘在科学计算及工程应用中经常遇到复对称线性系统问题,近年来对一种特殊类型的复对称线性系统的研究已成为一个热点.基于白中治等的PMHSS方法(Bai Z Z,Benzi M,Chen F,Wang Z Q.Preconditioned MHSS iteration methods for a class of block twoby-two linear systems with applications to distributed control problems.IMA J Numer Anal,2013,33:343-369),提出一类新的PMHSS迭代法用于求解这种特殊形式的复对称线性系统,给出新方法的收敛性理论以及最优参数的表达式,最后用数值例子展示了新方法的有效性.
