“…For continuous-time systems with time delays, some of the useful tools in robust stability analysis have been well developed based on the Lyapunov's second method, the Lyapunov-Krasovskii theorem and the Lyapunov-Razumikhin theorem. Following its success in stability analysis, the utility of Lyapunov-Krasovskii functionals were subsequently explored in adaptive control designs for continuous-time time delayed systems Ge et al (2003;; Ge & Tee (2007);Wu (2000); Xia et al (2009);Zhang & Ge (2007). However, in the discrete-time case there dos not exist a counterpart of Lyapunov-Krasovskii functional.…”