1. Electronic and Information and the Guangxi Key Laboratory of Multimedia Communications and Network Technology, School of Computer, Guangxi University, Nanning, China
2. School of Computer, Electronic and Information, Guangxi University, Nanning, China
3. Guangxi Key Laboratory of Multi-Source Information Mining Security, Guangxi Normal University, Guilin, China
4. School of Computing and Mathematical Sciences, University of Leicester, Leicester, U.K.
5. Shenzhen Institute of Advanced Technology, School of Computer Science and Control Engineering, Chinese Academy of Sciences, Shenzhen, China