1. School of Information, Beijing Wuzi University, Beijing 101149, China
2. Department of Mathematics and Statistics, University of South Florida, Tampa, FL 33620-5700, USA
3. Department of Mathematics, Zhejiang Normal University, Jinhua 321004, Zhejiang, China
4. Department of Mathematics, King Abdulaziz University, Jeddah, Saudi Arabia
5. School of Mathematics, South China University of Technology, Guangzhou 510640, China
6. College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao 266590, Shandong, China
7. Sports Business School, Beijing Sport University, Beijing 100084, China
8. School of Information, University of International Business and Economics, Beijing 100029, China