1. Department of Computer Science and Engineering, University of Engineering and Technology, Lahore 54000, Pakistan
2. Department of Computer Science, COMSATS Institute of Information Technology, Sahiwal 57000, Pakistan
3. Inst-Electric/Electron, College of the North Atlantic, P.O. Box 1150, St. John's, NL, Canada
4. Department of Computer Engineering, Bahria University, Islamabad 44000, Pakistan