1. School of Mathematical Sciences; University of Chinese Academy of Sciences; Beijing China
2. Department of Biostatistics; Yale University; New Haven Connecticut United States of America
3. Merck Research Lab; Rahway New Jersey United States of America
4. School of Economics and Wang Yanan Institute for Studies in Economics; Xiamen University; Fujian Sheng China
5. School of Statistics; Remin University of China; Beijing China