4 papers
An improved method for the computation of the Moore-Penrose inverse matrix
Vasilios N. Katsikis, Dimitrios Pappas, Athanassios Petralias
In this article we provide a fast computational method in order to calculate the Moore-Penrose inverse of singular square matrices and of rectangular matrices. The proposed method…
Restricted Linear Constrained Minimization of quadratic functionals
Dimitrios Pappas
In this work a linearly constrained minimization of a positive semidefinite quadratic functional is examined. Our results are concerning infinite dimensional real Hilbert spaces, w…
Minimization of Constrained Quadratic forms in Hilbert Spaces
Dimitrios Pappas
A common optimization problem is the minimization of a symmetric positive definite quadratic form under linear constrains. The solution to this problem may be given usin…
Factorizations of EP operators
Dimosthenis Drivaliaris, Sotirios Karanasios, Dimitrios Pappas
In this paper we characterize EP operators through the existence of different types of factorizations. Our results extend to EP operators existing characterizations for EP matrices…