1. School of Management Science and Engineering, Shanxi University of Finance & Economics Taiyuan, Shanxi 030006, China. Phone: (+86) 351-7666936
2. College of Business and Economics, University of Wisconsin, Whitewater Whitewater, WI 53190, USA. Phone: (+1) (262) 472-4798
3. Department of Computer, Taiyuan University, Taiyuan, Shanxi 030032, China
4. School of Management Science and Engineering, Shanxi University of Finance & Economics, Taiyuan, Shanxi 030006, China