1. Department of Computer Engineering, Taiyuan Institute of Technology, Taiyuan, Shanxi Province, P. R. China
2. Shanxi Key Laboratory of Signal Capturing & Processing, North University of China, Taiyuan, Shanxi, P.R. China
3. School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, Shanxi Province, P.R. China
4. School of Mathematics and Information Science, Zhangjiakou University, Zhangjiakou, Hebei Province, P.R. China
5. Department of Computer Engineering, Taiyuan Normal University, Taiyuan, Shanxi Province, P.R. China