Subdirect sums of weakly chained diagonally dominant matrices

Some sufficient conditions ensuring that the subdirect sum of two weakly chained diagonally dominant matrices is in this class, are given. In particular, it is shown that the subdirect sum of overlapping principal submatrices of a weakly chained diagonally dominant matrix is also a weakly chained diagonally dominant matrix.     

S-严格对角占优迭代矩阵最大模估计

对S-严格对角占优矩阵M,给出了迭代矩阵M^(-1)N的无穷范数的上界,推广和改进了胡家赣和Moraca等人的有关结果.     

Singular Sturmian separation theorems for nonoscillatory symplectic difference systems

ABSTRACT

In this paper, we derive new singular Sturmian separation theorems for nonoscillatory symplectic difference systems on unbounded intervals. The novelty of the presented theory resides in two aspects. We introduce the multiplicity of a focal point at infinity for conjoined bases, which we incorporate into our new singular Sturmian separation theorems. At the same time we do not impose any controllability assumption on the symplectic system. The presented results naturally extend and complete the known Sturmian separation theorems on bounded intervals by J. V. Elyseeva [Comparative index for solutions of symplectic difference systems, Differential Equations 45(3) (2009), pp. 445–459, translated from Differencial'nyje Uravnenija 45 (2009), no. 3, 431–444], as well as the singular Sturmian separation theorems for eventually controllable symplectic systems on unbounded intervals by O. Do?lý and J. Elyseeva [Singular comparison theorems for discrete symplectic systems, J. Difference Equ. Appl. 20(8) (2014), pp. 1268–1288]. Our approach is based on developing the theory of comparative index on unbounded intervals and on the recent theory of recessive and dominant solutions at infinity for possibly uncontrollable symplectic systems by the authors [P. ?epitka and R. ?imon Hilscher, Recessive solutions for nonoscillatory discrete symplectic systems, Linear Algebra Appl. 469 (2015), pp. 243–275; P. ?epitka and R. ?imon Hilscher, Dominant and recessive solutions at infinity and genera of conjoined bases for discrete symplectic systems, J. Difference Equ. Appl. 23(4) (2017), pp. 657–698]. Some of our results, including the notion of the multiplicity of a focal point at infinity, are new even for an eventually controllable symplectic difference system.     

基于运行数据的加热器主导因素建模

实现对回热加热器的实时在线性能监测,关键在于要建立高精度的回热加热器模型.本文采用主导因素建模法,在回热加热器稳态模型基础上新增特性参数,以提高模型在非稳态工况的适用性.5000组工况验证结果显示,模型改进后输出应达值与实际测量值的平均偏差较稳态模型减小了0.21％,标准差在抽汽侧和给水侧较稳态模型分别减少了19.5％...     

求分块带状方程组的新算法

<正>1引言在网络,自动化理论,差分方程求解及逻辑电路等实际问题中,往往需要求解分块带状方程组HX=F(1)这里H=(H_(ij)_(n×n),其中     

On the parallel GSAOR method for block diagonally dominant matrices

In this paper we consider the parallel generalized SAOR iterative method based on the generalized AOR iterative method presented by James for solving large nonsingular system. We obtain some convergence theorems for the case when coefficient matrix is a block diagonally dominant matrix or a generalized block diagonal dominant matrix. A numerical example is given to illustrate to our results.     

α-对角占优与广义严格对角占优矩阵的判定

1 引言与记号 广义严格对角占优矩阵在数学、物理、控制论及经济学等许多领域有着重要的研究价值和实用价值.广义严格对角占优矩阵就是非奇异日一矩阵,它是一类范围很广的特殊矩阵,熟知的严格对角占优矩阵,不可约对角占优矩阵,非奇异M-矩阵等都是其特殊情形.如何在实际应用中简便地判别一个矩阵是否是日一矩阵,一直是人们关注的问题.     

一类0-1二次规划最优解的新算法

从矩阵的基础知识出发,给出了当目标函数矩阵是严格对角占优阵时,快速地获得0-1二次规划最优解的一个新算法;该方法具有很强的实用性,是此类问题的一个高效求解算法.     

广义严格对角占优矩阵的充分条件

1 引言 广义严格对角占优矩阵是一类在数值代数、数学物理和控制论等领域有着广泛应用的特殊矩阵,例如:线性方程组Ax=b,当系数矩阵A为广义严格对角占优矩阵时,许多经典的迭代算法均是收敛的,同时对目前提出的一些修正算法也是收敛的.