| 2016. 3 - | Director, Haesung Institute of Ethics in International Affairs Institute, South Korea |
| 2013. 9 - | Associate Professor, Department of Political Science and Diplomacy, Yonsei University, South Korea |
| 2013. 3 - | Director, Center for Maritime Affairs, Institute of East and West Studies, Yonsei University, South Korea |
| 2015.9 - 2018.11 | Advisor, Ministry of Unification Policy Advisory Committee, South Korea |
| 2016.3 - 2018.2 | Research Policy Vice-President, Yonsei University Industry Foundation, South Korea |
| 2011.3 - 2013.8 | Vice-President, Institute of East and West Studies, Yonsei University, South Korea |
| 2007. 9 - 2009.2 | Research Professor, Kim Dae-jung Library, Yonsei University, South Korea |
| 2006. 9 - 2007. 7 | Research Associate, Princeton Institute for International and Regional Studies, Princeton University, NJ, USA |
| 2001. 9 - 2006. 8 | Research Professor, Korea Institute for National Unification, Yonsei University, South Korea |
| 1993. 7 - 1995. 3 | Research Fellow, Public Information Policy Office, Bureau of Public Information, South Korea |