1. School of Mathematics and Information Science and Henan Engineering Laboratory for Big Data Statistical Analysis and Optimal Control, Henan Normal University, Xinxiang, Henan 453007, P. R. China
2. Department of Applied Mathematics, Illinois Institute of Technology, Chicago, IL 60616, USA
3. School of Mathematics, South China University of Technology, Guangzhou, Guangdong 510640, P. R. China
4. College of Science, National University of Defense Technology, Changsha, Hunan 410073, P. R. China