1. Department of Mathematics, Faculty of Arts and Sciences, Cankaya University, 06530 Ankara, Turkey
2. Institute of Space Sciences, P.O. Box MG-23, R 76900 Magurele-Bucharest, Romania
3. Department of Electrical Engineering, University of Bojnord, P.O. Box 94531-1339, Bojnord, Iran
4. Department of Electrical and Computer Engineering, Hakim Sabzevari University, Sabzevar, Iran
5. Faculty of Computer Science, Białystok University of Technology, Wiejska 45A, Białystok, Poland