1. Department of Mathematics, School of Science, Hainan University, Haikou, Hainan Province, China
2. School of Life and Pharmaceutical Science, Haikou, Hainan Province, China
3. School of Electrical and Information Engineering, Anhui University of Science and Technology, Huainan, Anhui Province, China
4. College of Information Science and Engineering, Ocean University of China, Qingdao, Shandong Province, China
5. School of Economics, Hainan University, Haikou, Hainan Province, China