1995.9  - current: Professor, Electrical and Electronics Engineering, Yonsei University

2002.3 - 2003.2 : Visiting Professor, University of Waterloo, Waterloo, Ontario, Canada.

1994.5 - 1996.8: Senior Engineer,   Qualcomm Inc., San Diego, California

1992.1 - 1994.4: Post-Doc Research Associate,  Communication Science Institute at USC

1986.9 - 1991.12: PHD at USC, Dept of EE-Systems (Advisor: Dr.   S. W. Golomb )

1984.9 - 1986.5: MSEE at USC, Dept of EE-Systems

1980.3 - 1984.2: BS Eng. at Yonsei University, Dept of Electronics