“…Several papers actually applied this technique, among them is [5], even though their problem is a non-convex one and they claim that they were able to obtain an optimal solution. Other papers include: [28], [40], [41], [43], [44], [49], [58], [68], [45], [59], [75], [76], [77], [79], and [80]. El-Sherif and Mohamed [71] used this technique to obtain sub-optimal solution to their problem.…”