1. College of Computer Science, Sichuan Normal University, Chengdu, China
2. State Key Laboratory of Integrated Service Networks, Xidian University, Xi’an, China
3. Department of Electrical and Computer Engineering, University of Windsor, Windsor, Canada
4. School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, China
5. Department of Sciences and Informatics, Muroran Institute of Technology, Muroran, Japan
6. Department of Information and Electronic Engineering, Muroran Institute of Technology, Muroran, Japan