1. Graduate School of Computer Science and Technology, Hainan University, Haikou, China
2. School of Information Science, Nagoya University, Nagoya, Japan
3. College of Information and Computer, Taiyuan University of Technology, Taiyuan, China
4. Institute of Automation, Chinese Academy of Sciences, Beijing, China
5. School of Computer Science and Technology, Hainan University, Haikou, China
6. School of Information Science, Japan Advanced Institute of Science and Technology, Nomi, Japan