Department of Statistics, University of California, Riverside, CA, USA. xinping.cui@ucr.edu|Department of Statistics, University of California, Riverside, CA, USA. xinping.cui@ucr.edu|Department of Statistics, University of California, Riverside, CA, USA. xinping.cui@ucr.edu|Department of Statistics, University of California, Riverside, CA, USA. xinping.cui@ucr.edu|Department of Statistics, University of California, Riverside, CA, USA. xinping.cui@ucr.edu