1. College of Finance and Mathematics, West Anhui University, Lu'an, Anhui, China
2. Financial Risk Intelligent Control and Prevention Institute of West Anhui University, Lu'an, Anhui, China
3. School of Mathematics and Information Sciences, Henan Normal University, Xinxiang, Henan, China
4. School of Economics and Management, Nanjing University of Science and Technology, Nanjing, Jiangsu, China