1. Electrical Engineering Department, University of Zanjan, Zanjan 45371-38791, Iran
2. Electrical Engineering Department, University of Zanjan, P.O. Box 38791-45371, Zanjan 45371-38791, Iran e-mail:
3. Department of Mathematics and Computer Sciences, Faculty of Arts and Sciences, Çankaya University, Ankara 06530, Turkey; Institute of Space Sciences, Magurele-Bucharest 77125, Romania