[1] Ain Shams Univ, Engn Phys & Math Dept, Cairo 11517, Egypt
[2] 15th May Higher Inst Engn, Math Phys & Engn Sci Dept, Cairo 11731, Egypt
[3] Future Univ Egypt, Fac Engn & Technol, Cairo 11835, Egypt
[4] Brunel Univ London, Elect & Comp Engn Dept, Uxbridge UB8 3PH, Middx, England