“…After several decades of development, search problems are still largely of the same form as in 1942: a single target is lost and the problem is to find it efficiently. Therefore, the study of search plans for a lost target that either stationary or which move according to a known random motion has a remarkable importance in our life, because it has various applications like searching for a faulty unit in large linear system such as electrical power lines, petrol or gas supply under ground, missing boats and submarines, mining systems and search for a randomly located goal at two separated regions (see, e.g., El-Rayes and Mohamed, 1998Mohamed, , 1986Oshumi, 1991;El-Rayes et al, 2003;Mohamed et al, 2009Mohamed et al, , 2011Alpern and Haward, 2000).…”