1. Department of Mathematics, Harbin University of Science and Technology, Harbin, People's Republic of China
2. Department of Computer Science, Brunel University London, Uxbridge, UK
3. School of Automation, Harbin University of Science and Technology, Harbin, People's Republic of China
4. School of Mathematics and Physics, Anhui Polytechnic University, Wuhu, People's Republic of China
5. School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, People's Republic of China