1. School of Information, Beijing Wuzi University, Beijing 101149, China
2. School of Economics and Management, The Open University of China, Beijing 100039, China
3. School of Mathematics and Statistics, The University of Melbourne, Parkville, VIC 3010, Australia
4. Center for Applied Statistics, School of Statistics, Renmin University of China, Beijing 100872, China
5. School of Statistics and Information, Xinjiang University of Finance and Economics, Urumqi 830026, China