1. Jianping Chen:
Faculty of Computer, Zhaoqing University, Zhaoqing 526061, Guangdong, China
2. Jianbin Wang:
Faculty of Computer, Zhaoqing University, Zhaoqing 526061, Guangdong, China
3. Yimin Yang:
Faculty of Automation, Guangdong University of Technology, Guangzhou 510090, Guangdong, China
4. Qijun Xiao:
Faculty of Electronic Information and Mechnical & Electrical Engineering, Zhaoqing University, Zhaoqing 526061, Guangdong, China