1. School of Computer Science, University of South China, Hengyang, China
2. School of Computer Science, Huazhong University of Science and Technology, Wuhan, China
3. Department of Electrical and Computer Engineering, Suffork University, Boston, MA, USA
4. School of Computing, Engineering and Mathematics, Western Sydney University, Sydney, NSW, Australia
5. Department of Electronic Engineering, Tsinghua University, Beijing, China