Theoretical research of Non-linear partial differential equation

1989~1990 Indiana University Post-doctoral researcher
1990~1991 Brown University Research Assistant Professor
1991-1994 POSTECH, Assistant Professor of Mathematics
1994-1998 Seoul National University, Assistant Professor of Mathematics
1998-1999 University of Minnesota Visiting Associate Professor
1998-2003 Seoul National University, Associate Professor of Mathematics
2003-2004 Seoul National University, Professor of Mathematics
2004-2012 Sungkyunkwan University, Professor of Mathematics
2004~ Member of the Korea Advanced Institute of Science and Technology.
2006-2007 RIMS(Kyoto University, Japan) Visiting Professor
2007-2010 University of Chicago Visiting Professor
2012~ Honorary Chair Professor of Mathematics at Chung-Ang University.

1996 Science and Technology Excellence Paper Award ( KOFST, The Korean Federation of Science and Technology Societies)
2004 Korea Science Awards (KOSEF, Korea Science and Engineering Foundation)
2006 Star Faculty(MEST, Ministry of Education, Science and Technology)
2012 Advances in Mathematics Most-cited Articles award(Elsevier Inc.)