1. International Institute of Finance, School of Management, University of Science and Technology of China, Hefei, China;
2. Department of Biostatistics, Yale University, New Haven, CT;
3. Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China;
4. Center for Statistics and Data Science, Beijing Normal University at Zhuhai, Zhuhai, China;
5. Department of Mathematics, Hong Kong Baptist University, Kowloon Tong, Hong Kong