1. Mathematics and Computer Science Department, Faculty of Science, Menoufia University, Al Minufya, Egypt
2. Department of Computer Science, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia
3. Computer Science Department, Faculty of Applied Science, Taiz University, Taiz, Yemen
4. Department of Basic Science, Modern Academy, Cairo, Egypt
5. Department of Computer and Information Science, Linköping University, Linköping, Sweden
6. Faculty of Science, Fayoum University, Faiyum, Egypt
7. School of Information Technology and Computer Science, Nile University, Giza, Egypt