[1] Univ North Carolina Charlotte, Dept Math & Stat, Charlotte, NC 28223 USA
[2] MSD R&D China Co Ltd, Biostat & Res Decis Sci Asia Pacific, Beijing, Peoples R China
[3] Univ Washington, Dept Biostat, Seattle, WA 98195 USA
[4] Fred Hutchinson Canc Res Ctr, 1124 Columbia St, Seattle, WA 98104 USA
[5] Univ North Florida, Dept Math & Stat, Jacksonville, FL USA
[6] East China Univ Sci & Technol, Sch Math, Shanghai, Peoples R China