School of Statistics, Capital University of Economics and Business, Fengtai, Beijing, China.|Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.|Institute of Statistical Science, Academia Sinica, Nankang, Taipei, Taiwan.|Department of Statistics, College of Arts and Sciences, University of South Carolina, Columbia, SC, USA.|Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.