1. School of Electrical Engineering and the Guangxi Key Laboratory of Multimedia Communications and Network Technology, Guangxi University, Nanning, China
2. School of Electrical Engineering and the Guangxi Key Laboratory of Power System Optimization and Energy Technology, Guangxi University, Nanning, China
3. School of Computer, Electronics and Information and the Guangxi Key Laboratory of Multimedia Communications and Network Technology, Guangxi University, Nanning, China