1. School of Economics and Management, Southeast University, Nanjing 211189, P.R. China
2. Department of Mathematics, Southern University of Science and Technology, Shenzhen 518055, China
3. Department of Mathematics and RiskLab, ETH Zurich, 8092 Zurich, Switzerland
4. Advanced Modeling and Applied Computing Laboratory, Department of Mathematics, The University of Hong Kong, Pokfulam Road, Hong Kong and Hughes Hall, Wollaston Road, Cambridge CB1 2EW, U.K. School of Economics and Management, Beijing University of Chemical Technology, North Third Ring Road, Beijing 100029, China
5. Department of Actuarial Studies and Business Analytics, Macquarie Business School, Macquarie University, Sydney NSW 2109, Australia