1. Bing Li is Professor, Department of Statistics, Pennsylvania State University, University Park, PA 16802 . Songqiao Wen is Ph.D. Student, Department of Mathematics, Hong Kong Baptist University, Kowloon Tong, Hong Kong . Lixing Zhu is Professor, Department of Mathematics, Hong Kong Baptist University, Kowloon Tong, Hong Kong and Cheung Kong Chair Professor, Renmin University, Beijing, China. Li's research is supported in part by grants DMS-0405681 and DMS-0704621 of the National Science Foundation....