1. Department of Biostatistics, School of Public Health; Yale University; New Haven CT USA
2. School of Statistics and Management; Shanghai University of Finance and Economics; Shanghai China
3. Department of Statistics and Actuarial Science; University of Iowa; Iowa City IA USA
4. Division of Epidemiology and Biostatistics; UIC School of Public Health; Chicago IL USA
5. Center for Applied Statistics, School of Statistics; Renmin University of China; Beijing China
6. School of Statistics; Capital University of Economics and Business; Beijing China