A method with high convergence rate for finding approximate inverses of nonsingular matrices is suggested and established analytically. An extension of the introduced computational scheme to general square matrices is defined. The extended method could be used for finding the Drazin inverse. The application of the scheme on large sparse test matrices alongside the use in preconditioning of line...

This paper presents the use of an iteration method to solve the identifiability problem for a class of discretized linear partial differential algebraic equations. This technique consists in replacing the partial derivatives in the PDAE by differences and analyzing the difference algebraic equations obtained. For that, the theory of discrete singular systems, which involves Drazin inverse matri...

The generalized inverse A T ,S of a matrix A is a {2}-inverse of A with the prescribed range T and null space S. A representation for the generalized inverse A T ,S has been recently developed with the condition σ(GA|T ) ⊂ (0,∞), where G is a matrix with R(G) = T and N(G) = S. In this note, we remove the above condition. Three types of iterative methods for A T ,S are presented if σ(GA|T ) is a...

Singular systems have been studied extensively during the last two decades due Abstract to their many practical applications. Such systems possess numerous properties not shared by the well-known state variable systems. This paper considers the linear tracking problem for the continuous-time singular systems. The Hamilton-Jacobi theory is used in order to compute the optimal control and associa...

We study semi-iterative methods for an approximate solution of a linear equation x = Tx+c with a bounded linear operator T acting on a Banach space X, considering separately the cases when λ = 1 is an isolated and accumulation spectral point for T . We give necessary and sufficient conditions for the convergence of a semi-iterative method, utilizing the generalized Drazin inverse introduced by ...

The paper solves a long standing problem of finding error bounds for a general perturbation of the Drazin inverse. The bounds are given in terms of the distance between the matrices together with the distance between their eigenprojections. Estimates using the gap between subspaces are also given. Recent results of several authors, including Castro, Koliha, Straškraba, Wang and Wei can be recov...

In this paper, let A and B be n x p complex tensors = + E. Denote the T-Drazin inverse of by AD. We give a perturbation bound for ||BD-AD||=||AD|| under condition (W). Considering solution singular tensor equation A* b, (b ? R(AD)) at same time. The optimal system equations have been given.