Institution: | 1. School of Mathematical Sciences, Capital Normal University, Beijing 100048, China;2. Department of Mathematics and Statistics, University of North Carolina at Charlotte, NC 28223, U.S.A.;3. School of Mathematics, Center for Applied Statistical Research, Jilin University, Changchun 130012, China;4. Department of Statistics, University of Missouri, Columbia, MO 65211, U.S.A. |