In this article, we update the reference [14] in two aspects. First, we note that in order for the control law (12) in [14] to be equivalent to the control law (3) in [14], we need to assume that the samplings for all subsystems must be synchronous, i.e., we need to assume that Ti = T for all i = 1, · · · , N . Second, we extend our results from periodic sampling to aperiodic sampling.