1. School of Information and Software Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, P.R. China
2. School of Information Science and Engineering, Chengdu University, Chengdu, Sichuan, P.R. China
3. Division of IT Convergence Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
4. School of Mathematics Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan, P.R. China
5. School of Electrical Engineering, Chungbuk National University, Chungdae-ro, Seowon-Gu, Cheongju, South Korea