与M-矩阵相关的一类二次矩阵方程的新迭代法（英文）

本文研究与M-矩阵相关的一类二次矩阵方程的数值解法.这类方程源于马尔可夫链的带噪Wiener-Hopf问题,其解中具有实际意义的是M-矩阵解.通过简单的变换,将该二次矩阵方程转化为M-矩阵代数Riccati方程.提出一种新的迭代方法,并对其进行收敛性分析.数值实验表明,新的迭代方法是可行的,且在一定条件下比现有的一些方法更为有效.     

非负不可约矩阵的广义Perron补矩阵

1989年Meyor为计算马尔可夫链的平稳分布向量构造了一个算法，首次提出非负不可约矩阵的Perron补矩阵的概念，本给出非负不可约矩阵A的广义Perron补矩阵若干性质，并且证明若矩阵A是不可约逆M-矩阵，其广义Perron补矩阵也是不可约逆M-矩阵。     

M-矩阵Sylvester方程的一类Smith-like迭代法（英文）

本文研究了M-矩阵Sylvester方程的数值解法,这类矩阵方程广泛出现在科学计算和工程应用的许多领域.利用M-矩阵的性质和Smith方法的思想,提出了一类Smith-like迭代法以求解M-矩阵Sylvester方程,并给出了新方法的收敛性分析.数值实验表明,新方法是可行的,而且在一定条件下也是较为有效的.     

布尔矩阵平方根问题及其与图着色问题的关系

讨论了布尔矩阵平方根问题及其与图着色问题的关系.首先得到有平方根的布尔矩阵具有的一些性质;然后给出布尔矩阵存在平方根的一个充要条件;最后证明布尔矩阵的平方根问题可以转化为简单图的着色问题.     

非奇异M-矩阵模最小特征值的界

正1引言与预备知识非奇异M-矩阵首先是由美国数学家Ostrowski在1937年提出的,这个重要的矩阵类起源于矩阵计算中迭代程序之收敛性研究.非奇异M-矩阵模最小特征值的计算一直是矩阵分析与计算数学领域里的热门课题,近年来受到许多学者的青睐,并取得了一系列的研究结果[1-5].本文在前人的基础上,给出非奇异M-矩阵模最小特征值的新界值.     

逆为三对角矩阵的逆M-矩阵

本文研究了一类特殊的逆M-矩阵.利用有向图中的性质和方法,获得了逆M-矩阵其逆为三对角矩阵的充分必要条件,推广了常见的D-型矩阵,得到了一类矩阵为逆M-矩阵的条件.     

M-矩阵的性质与Hadamard-Fisher不等式的注记

主要研究了两个M-矩阵的比较性质与不等式,给出了M-矩阵与逆M-矩阵Hadamard-Fisher不等式等式成立的矩阵结构.     

循环逆M-矩阵的判定

给出了循环逆M-矩阵的判定方法:如果一个n×n非负循环矩阵非正且不等于c0I,若存在一个正整数K是n的真因子,使得cjk0,j=0,1[,…,n-k]k,其余的ci等于0且Circ[c0,ck,…,cn-k]是一个逆M-矩阵,则A是一个逆M-矩阵.     

M-矩阵和逆M-矩阵的Hadamard积(英文)

A=[a_ij]∈M_n和B=[b₍ij(]∈M_n的Hadamard积可表示为AoB=[a_ijb_ij]∈M_n.如果A,B∈M_n是M-矩阵,那么AoB^-1也是M-矩阵.证明了（a）一个非奇异的M-matrix是一对M-矩阵和逆M-矩阵的Hadamard积,同时也证明了（b）一个P-矩阵是两个P-矩阵的Hadamard积.     

循环逆M-矩阵的判定

给出了循环逆M-矩阵的判定方法:如果一个n×n非负循环矩阵非正且不等于c0I,若存在一个正整数K是n的真因子,使得cjk>0,j=0,1[,…,n-k]k,其余的ci等于0且Circ[c0,ck,…,cn-k]是一个逆M-矩阵,则A是一个逆M-矩阵.     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Bounds for the zeros of polynomials

Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.     

Boundedness of commutators related to Marcinkiewicz integrals on hardy type spaces

In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 ＜β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 ＜α≤ 1).     

Generalization of the interaction between Haar approximation and polynomial operators to higher order methods

In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f（u） of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.     

Jacobi polynomials used to invert the laplace transform

Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.