1. College of Electronic Science and the College of Computer, National University of Defense Technology, Changsha, China
2. Department of Mechanical Engineering, Keio University, Yokohama, Japan
3. Wuhan Electronic Information Institute, Wuhan, China
4. College of Electronic Science, National University of Defense Technology, Changsha, China
5. School of Mathematics and Statistics, Beijing Institute of Technology, Beijing, China
6. College of Computer, National University of Defense Technology, Changsha, China