1. Complex Systems Research Center, Shanxi University, Taiyuan 030006, Shanxi, China, and Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis for Disease Control and Prevention, Taiyuan 030006, Shanxi, China (, , ).
2. LSEC & NCMIS, Institute of Computational Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190, China .