1. School of Computer Science and Engineering, and Guangxi Key Laboratory of Embedded Technology and Intelligent System, Guilin University of Technology, Guilin, China
2. School of Computer Science and Engineering, Guilin University of Technology, Guilin, China
3. School of Computer Science and Information Engineering, Hubei University, Wuhan, China
4. School of Cyberspace Science and Technology, Beijing Institute of Technology, Beijing, China