Outer Generalized Inverses in Rings

ABSTRACT

In this article we formulate basic results on outer generalized inverses of elements in rings. We characterize elements which have the same idempotents related to their particular outer generalized inverses and investigate positive generalized inverses in C*-algebras.     

Characterizing consistency in probabilistic logic for a class of Horn clauses

The problem of consistently assigning probabilities to logical formulas is an important problem. In this paper a set of logical formulas will be identified for which the problem can be solved. For every directed graph we define a set of logical formulas that it represents. If the underlying (undirected) graph is either perfect or t-perfect a closed form solution to the consistency problem can be given. A remarkable property of the class of formulas identified here is that it turns out to be closed under duality (if a set of formulas is represented by a digraph then the dual set of formulas is also represented by a digraph).     

On the perturbation of least squares problems with equality constraints

Some new perturbation results are presented for least squares problems with equality constraints, in which relative errors are obtained on perturbed solutions, least squares residuals, and vectors of Lagrange multipliers of the problem, based on the equivalence of the problem to a usual least squares problem and optimal perturbation results for orthogonal projections.     

Invertibility in rings of the commutator ab – ba,where aba=a and bab=b

Let ? be a ring and a,?b∈? satisfy aba?=?a and bab?=?b. We characterize when ab???ba is invertible. This study is specialized when ? has an involution and when b is the Moore–Penrose inverse of a.     

关于广义逆矩阵AT,S^（2）的极限表示的注记

1引言文[1]中应用广义逆矩阵A_r.s~(2)的一个极限表示给出了计算A_r.s~(2)r嵌入法(imbeddingmethod).但对其主要结果定理1,即A_r.s~(2)的极限表示。并没有给出严格的证明，实际上其证明并不是显然的。本文于此给出A_r.s~(2)的极限表示的一种严格的证明，并叙述许多常用广义逆的极限表示，作为文[1]的补充。     

分块矩阵[A B]中一块的广义逆

给出矩阵[A B]的广义逆,其中A∈Cm×k,B∈Cm×(n-k),本文得到子块A的相关广义逆的计算公式.     

一类广义对称矩阵反问题有解的条件

本研究一奥广义对称矩阵反问题的有解条件．给出问题P有解的充要条件。     

On the Extrema of Linear Least-Squares Problems

We use the concept of generalized inverses to show that the extrema of the function are minima, A being a rectangular matrix not necessarily of full rank     

On the exact control of mechanical systems

A general procedure for obtaining the exact control forces to be exerted on a mechanical system to maintain constraints is introduced in this paper. It is illustrated through a simple example. The discussion extends to Nature's choice of control forces and its relation to the general control forces.     

Method of elementary transformation to compute Moore-Penrose inverse

Method of elementary transformation to compute Moore-Penrose inverse is given by applying the rank equalities of matrix. The inheritable properties of Moore-Penrose inverse on rank are also discussed.     

子空间上亚半正定矩阵反问题解存在的条件

1 引 言 本文用R~(m×n)表示全体m×n阶实矩阵的集合,R~n为所有n维列向量的全体,OR~(n×n)为n阶正交矩阵的集合,I_n为n阶单位矩阵,A~T,A~ ,B(A),R(A)~⊥,N(A)分别表示矩阵A的转置,Moore-Penrose广义逆,值域,值域的正交补空间及零空间,Ps是     

A note on the stability of a pth order iteration for finding generalized inverses

A number of papers intended for the numerical computation of generalized inverses by means of higher-order iterative methods have been published recently. This note investigates the numerical stability of a general family of iterative methods in order to complete the previous studies in this trend of research.     

Uniform Convergence of Fourier–Jacobi Series

Necessary and sufficient conditions which imply the uniform convergence of the Fourier–Jacobi series of a continuous function are obtained under an assumption that the Fourier–Jacobi series is convergent at the end points of the segment of orthogonality [−1,1]. The conditions are in terms of the modulus of continuity, Λ-variation, and the modulus of variation of a function.     

函数列一致收敛判别法

利用函数列和函数一致连续的有关性质,得到了函数列一致收敛新的判别法.     

约束矩阵方程的解的表示及行列式公式

本文利用Ｂｏｔｔ－Ｄｕｆｆｉｎ逆导出约束矩阵方程的唯一解或通解的表示及其较为简洁的行列式公式，并由之给出了某些特殊矩阵方程与约束性方程组的解以及几个重要广义逆矩阵的表示及其较是洁的行列式公式，我们的结果改进与推广了文（２－１１，１４，１５）中的有关结果。