1. Faculty of Mathematics, Shiraz University of Technology, Shiraz, Iran
2. Department of Applied Mathematics, Faculty of Mathematical Sciences, Shahrekord University, Shahrekord, Iran
3. Department of Mathematics, K.N. Toosi Univ. of Tech., Tehran, Iran
4. Scientific Computations in Optimization and Systems Engineering (SCOPE), K.N. Toosi Univ. of Tech., Tehran, Iran
5. Department of Mathematics and Statistics, York University, Toronto, Canada