Ju. M. Berezanskii and I. M. Gali, “Positive Definite Functions of an Infinite Number of Variables in a Layer,” Ukrainian Mathematical Journal, Vol. 24, No. 4, 1972, pp. 435-464.
has been cited by the following article:
TITLE: Optimality of Distributed Control for n × n Hyperbolic Systems with an Infinite Number of Variables
AUTHORS: Ahlam Hasan Qamlo
KEYWORDS: Hyperbolic Operators; Cooperative Systems; Spaces With an Infinite Number of Variables; Existence and Uniqueness of Solutions; Distributed Control Problems; Control Constraints; Variable Coefficients
JOURNAL NAME: Advances in Pure Mathematics, Vol.3 No.6, September 30, 2013
ABSTRACT: In this paper, we study the existence of solutions for 2l order (n × n) cooperative systems governed by Dirichlet and Neumann problems involving hyperbolic operators with an infinite number of variables and with variable coefficients. The necessary and sufficient conditions for optimality of the distributed control with constraints are obtained and the set of inequalities that defining the optimal control of these systems are also obtained.