1. School of Information Science and Engineering, Yanshan University, Qinhuangdao 066004, China
2. Department of Computer Science and Information Technology, La Trobe University, Melbourne 3083, Australia
3. School of Mathematical Science, Heilongjiang University, Harbin 150080, China
4. Key Laboratory for Computer Virtual Technology and System Integration of Hebei Province, Qinhuangdao 066004, China
5. Center for Frontier Medical Engineering, Chiba University, Chiba 2638522, Japan
6. Department of Computer Science, School of Engineering, Shantou University, Shantou 515063, China