PROCEEDINGS OF THE IRE Time - Varying Networks

This paper presents an analysis of some of the significant developments in time-varying network theory which have taken place during the past decade, with the emphasis placed on three topics: 1) characterization of time-varying networks, and in particular, transition from the impulsive response to the differential equation; 2) the problem of factorization, with emphasis on the contributions of Darlington, Batkov and Paul Levy; and 3) randomly-varying systems and, in particular, the question of stability of discrete-time systems of this type. The identification problem, the analysis of periodicallyvarying systems, the synthesis problem, and the filtering and prediction of nonstationary processes will be treated in Part II, to be published later.