Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu|Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu|Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu|Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu|Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu|Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu|Department of Statistics, 815 Patterson Office Tower, University of Kentucky, Lexington, Kentucky 40508-0027, USA. liping@ms.uky.edu