1. College of Mathematics Science, Chongqing Normal University, Chongqing, People's Republic of China
2. Key Laboratory for OCME, School of Mathematical Science, Chongqing Normal University, Chongqing, People's Republic of China
3. College of Management, Dalian Maritime University, Dalian, People's Republic of China
4. Department of Statistics, Feng Chia University, Taichung, Taiwan
5. Department of Business Administration, Cheng Shiu University, Kaohsiung, Taiwan