Vol.2, No 7, 1997 pp. 325-329
UDC 681.511.4
A QUALITATIVE METHOD FOR STABILITY ANALYSIS OF NONLINEAR DISCRETE DYNAMICAL SYSTEMS
Bratislav Danković1, Miomir Stanković2
1Faculty of Electronic Engineering, Niš Yugoslavia
2Faculty of Occupational Safety, Niš Yugoslavia

Abstract. Main results are presented by two theorems determining sufficient conditions for stability, and necessary conditions for instability of equilibrium point of a nonlinear discrete dynamical system. By introducing the concept of discrete divergence as a difference operator, a discrete analogue of the Liuvill theorem on expansion of phase volume was derived. This theorem was a base for the derivation of the presented results.
Key words: Stability, nonlinear system, discrete system, field theory, diveregence. 
KVALITATIVNI METOD ZA ANALIZU STABILNOSTI NELINEARNIH DISKRETNIH SISTEMA
U radu je izložen jedan nov metod za kvalitativnu analizu stabilnosti nelinearnih diskretnih sistema baziran na diskretnoj teoriji polja. Uveden je pojam diskretne diveregencije u vidu diferencnog operatora. Dat je diskretan analog Luivilove teoreme o širenju diskretnog faznog prostora. Glavni rezultati su dati u vidu dve teoreme o potrebnim uslovima za stabilnost i dovoljnim uslovima za nestabilnost diskretnih sistema.