He is an Assistant Professor (January 2006 - December 2006) in the same university.He is a Post-Doctoral Researcher (January 2004 - January 2006) in the Department of Automation, Tsinghua University. He is a Research Fellow (November 2006 - January2007) in the Department of Mathematics, City University of Hong Kong. He is a Senior Research Assistant (July 2005 - September 2005) in the same university.