1. Eastern Michigan Joint College of Engineering, Beibu Gulf University, Qinzhou 535011, P.R. China
2. Guangxi Key Laboratory of Ocean Engineering Equipment and Technology, Qinzhou 535011, P.R. China
3. Education Department of Guangxi Zhuang Autonomous Region, Key Laboratory of Beibu Gulf Offshore Engineering Equipment and Technology (Beibu Gulf University), Qinzhou 535011, P.R. China
4. Advanced Science and Technology Research Institute, Beibu Gulf University, Qinzhou 535011, P.R. China
5. Research Institute for Integrated Science, Kanagawa University, Yokohama, Kanagawa 259-1293, Japan
6. College of Electrical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China