G.George Yin Department of Mathematics Wayne State University Detroit,MI 48202,U.S.A. gyin@math.wayne.edu Qing Zhang Department of Mathematics University of Georgia Athens,GA 30602,U.S.A. qingz@math.uga.eduG.George Yin Department of Mathematics Wayne State University Detroit,MI 48202,U.S.A. gyin@math.wayne.edu Qing Zhang Department of Mathematics University of Georgia Athens,GA 30602,U.S.A. qingz@math.uga.edu Hanqin Zhang Academy of Mathematics and Systems Science,Academia Sinica Beijing,100190,China hanqin@amt.cn.ac and NUS Business School National University of Singapore Singapore,117592 bizzhq@nus.edu.sg