1. Phase transitions and dynamics of complex systems
2. Macroscopic and mesoscopic quantum phenomena
3. Physics of biological systems

1981~1981 Lecturer, Catholic University
1985~1986 Postdoctoral researcher, The Ohio State University
1987~1991 Assistant professor of physics, Seoul National
University
1991~1997 Associate professor of physics, Seoul National
University
1997~present Professor of physics, Seoul National University
1985~1986 Research collaborator, Los Alamos National
Laboratory
1989~1989 Visiting scientist, Brookhaven National Laboratory
1991~1991 Visiting assistant professor, University of
Washington
1993~1993 Visiting associate professor, University of
Washington
1993~1993 Visiting scholar, Lehigh University
1996~1996 Visiting associate professor, The Ohio State
University
1997~1997 Visiting scientist, Los Alamos National Laboratory
1997~1999 Executive Editor, Journal of the Korean Physical
Society
1997~1997 Visiting scholar, Simon Fraser University
1999~1999 Visiting scholar, Korea Institute for Advanced
Study
2000~2001 Visiting scholar, University of Washington
2002~2003 Visiting scholar, Korea Institute for Advanced
Study
2002~2002 Associate research director, CNRS, Louis Pasteur
University