On the existence of periodic solutions for large-scale systems

In recent ten years or more, many scholars have engaged in the investigation concerning the stability of large-scale systems, but up to the present, the problem on the existence of periodic solutions for large-scale systems has yet been seldomly touched upon in the literature.In this paper, by means of the method of constructing Lyapunov function. We study the problem on the existence of periodic solutions for linear and nonlinear large-scale systems, and obtain several sufficient conditions which guarantee the existence of periodic solutions.