Novel stability criteria on discrete-time neural networks with both time-varying and distributed delays

This paper investigates robust exponential stability for discrete-time recurrent neural networks with both time-varying delay (0 < or = tau(m) < or = tau(k) < or = tau(M)) and distributed one. Through partitioning delay intervals [0, tau(m)] and [tau(m), tau(M)], respectively, and choosing an augmented Lyapunov-Krasovskii functional, the delay-dependent sufficient conditions are obtained by using free-weighting matrix and convex combination methods. These criteria are presented in terms of linear matrix inequalities (LMIs) and their feasibility can be easily checked by resorting to LMI in Matlab Toolbox in Ref. 1. The activation functions are not required to be differentiable or strictly monotonic, which generalizes those earlier forms. As an extension, we further consider the robust stability of discrete-time delayed Cohen-Grossberg neural networks. Finally, the effectiveness of the proposed results is further illustrated by three numerical examples in comparison with the reported ones.