1. School of Information and Mathematics, Yangtze University, Jingzhou 434023, China
2. School of Environment, Education & Development (SEED), The University of Manchester, Manchester M139PL, UK
3. College of Applied Sciences, Beijing University of Technology, Beijing 100124, China
4. College of Mathematics and Information Science, Henan Normal University, Xinxiang 453007, China
5. School of Mathematics and Statistics, Huanghuai University, Zhumadian 463000, China