1. School of Business, Qingdao University, Qingdao 266061, China
2. School of Information and Software Engineering, University of Electronic Science and Technology, Chengdu 610054, China
3. Department of Computing, Letterkenny Institute of Technology, Co. Donegal, Ireland
4. Bahria University, Islamabad, Pakistan
5. Department of Electrical Engineering, University of Engineering and Technology, Peshawar, Pakistan
6. School of Telecommunication Engineering, Suranaree University of Technology, Thailand
7. Department of Mechanical and Industrial Engineering, College of Engineering, Qatar University, P.O. Box 2713 Doha, Qatar