“…In the past decades, the stability of neutral system has received a considerable Received: July 9, 2013 c 2013 Academic Publications, Ltd. url: www.acadpubl.eu § Correspondence author amount of attention from researchers ( [1], [3], [4], [5], [8], [10], [11], [13], [14], [15], [16], [17], [18], [19], [20], [21] and the reference therein). Because the neutral has time-delays in both the state and its derivative (so-called discrete and neutral delays), it can be used to describe various practical applications in sciences and engineering such as aircraft stabilization, lossless transmission lines, population ecology, chemical processes, etc [1], [2].…”