1. School of Mathematical Sciences, Sichuan Normal University, Chengdu, China
2. School of Manegement, Xi’an Jiaotong University, Xi’an, China
3. Division of Biostatistics, Jockey Club School of Public Health and PrimaryCare, Chinese University of Hong Kong, Shatin, Hong Kong
4. School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, China
5. Department of Industrial Engineering and Logistics Management, Hong Kong University of Science and Technology, Kowloon, Hong Kong