On properties of quadratic matrices.
On regular elements in an incline.
On solutions of a matrix equations system AX = B, XD = E
On solutions to the quaternion matrix equation .
On some Generalized Inverses of Matrices and some Linear Matrix Equations
On sums of - matrices.
On the approximation numbers of large Toeplitz matrices.
On the confidence region of a vector parameter
On the convergence theory of double -weak splittings of type II
Recently, Wang (2017) has introduced the -nonnegative double splitting using the notion of matrices that leave a cone invariant and studied its convergence theory by generalizing the corresponding results for the nonnegative double splitting by Song and Song (2011). However, the convergence theory for -weak regular and -nonnegative double splittings of type II is not yet studied. In this article, we first introduce this class of splittings and then discuss the convergence theory for these sub-classes...
On the diagonalisation of von Neumann regular matrices
On the Drazin index of regular elements
It is known that the existence of the group inverse a # of a ring element a is equivalent to the invertibility of a 2 a − + 1 − aa −, independently of the choice of the von Neumann inverse a − of a. In this paper, we relate the Drazin index of a to the Drazin index of a 2 a − + 1 − aa −. We give an alternative characterization when considering matrices over an algebraically closed field. We close with some questions and remarks.
On the group inverse of linear combinations of two group invertible matrices.
On the inverse of the adjacency matrix of a graph
A real symmetric matrix G with zero diagonal encodes the adjacencies of the vertices of a graph G with weighted edges and no loops. A graph associated with a n × n non–singular matrix with zero entries on the diagonal such that all its (n − 1) × (n − 1) principal submatrices are singular is said to be a NSSD. We show that the class of NSSDs is closed under taking the inverse of G. We present results on the nullities of one– and two–vertex deleted subgraphs of a NSSD. It is shown that a necessary...
On the Nonnegativity of XX* and its Relevance in Econometrics.
On the partitioned matrix and its associated system
On the pseudoinverse of a sum of symmetric matrices with applications to estimation
On the relation between Moore's and Penrose's conditions.
On the singular decomposition of matrices.
Operator matrix of Moore-Penrose inverse operators on Hilbert C*-modules
We show that the Moore-Penrose inverse of an operator T is idempotent if and only if it is a product of two projections. Furthermore, if P and Q are two projections, we find a relation between the entries of the associated operator matrix of PQ and the entries of associated operator matrix of the Moore-Penrose inverse of PQ in a certain orthogonal decomposition of Hilbert C*-modules.
Optimal design in small amplitude homogenization
This paper is concerned with optimal design problems with a special assumption on the coefficients of the state equation. Namely we assume that the variations of these coefficients have a small amplitude. Then, making an asymptotic expansion up to second order with respect to the aspect ratio of the coefficients allows us to greatly simplify the optimal design problem. By using the notion of H-measures we are able to prove general existence theorems for small amplitude optimal design and to provide...