二元二次对角逼近的逼近阶

给出了二元二次对角逼近的逼近阶     

保结构算法的相位误差分析及其修正

辛算法和保能量算法是应用最为广泛的两种保结构算法.本文从相位误差的角度给出了他们的比较结果.我们针对线性动力系统,分别分析了基于Pade对角逼近给出的辛算法和基于平均向量场法得到的能量守恒算法的相位误差,并通过数值验证了分析结果.文章还给出了保结构算法相位误差的改进方法,并通过数值例子验证了方法的有效性.     

矩阵相似与特征多项式相同的等价条件

本讨论了矩阵相似与特征多项式相同的等价条件及其相关结构，并指出湖南省某次线性代数自考题中一道命题的错误。     

非单调广义对角拟牛顿算法

本文研究了无约束最优化的求解问题.利用新的对角拟牛顿校正和非单调技术,获得了一种非单调广义对角拟牛顿算法.新算法具有低存储、低计算量的特点,非常适合大规模问题的求解,推广了文献[8]的结果.     

Diagonal Invariant Ideals of Topologically Graded C*-algebras

We study diagonal invariant ideals of topologically graded C~*-algebras over discrete groups. Since all Toeplitz algebras defined on discrete groups are topologically graded, the results in this paper have improved the first author's previous works on this topic.     

广义Nekrasov矩阵的细分迭代判别法

利用细分矩阵下标集合的思想,构造递进系数和特殊的正对角矩阵,结合不等式的放缩,给出广义Nekrasov矩阵的迭代判别法,推广和改进了已有相关结果,并用数值实例说明了所得结果的优越性.     

非奇异H矩阵的实用充分条件

In this paper, several practical sufficient conditions for nonsinguular H-matrices are obtained by comparing the elements of a matrix. Advantage of results obtained is illustrated by a numerical example.     

非奇H-矩阵的实用性新判定

给出了非奇H矩阵几个新的实用性判据,改进了近期的一些结果,并给出相应数值例子来说明结果的有效性.     

广义对角占优矩阵的判定准则

In this paper,some new sufficient conditions for generalized dominant matrices are given,and some results in [1] are generalized and improved.     

Efficient Runge-Kutta integrators for index-2 differential algebraic equations

In seeking suitable Runge-Kutta methods for differential algebraic equations, we consider singly-implicit methods to which are appended diagonally-implicit stages. Methods of this type are either similar to those of Butcher and Cash or else allow for the importation of a final derivative from a previous step. For these two classes, with up to three additional diagonally-implicit stages, we derive methods that satisfy appropriate order conditions for index-2 DAEs.