Postgraduate & Academic Activities
1984 present Korean Medical Association (KMA) Member
1989 present Korean Association of Internal Medicine (KAIM) Member
1989 present Korean Scociety of Gastrointestinal Endoscopy (KSGE) Member
1999 present American Gastroenterological Association (AGA) International member
1999 present American Association for the Study of Liver Diseases (AASLD) Member
1999 present The Korean Journal of Gastroenterology Assistant Editor
1999 present Korean Association for the Study of the Liver (KASL) Scientific member
1999 present Korean Society of Gastroenterology (KSG) Scientific member
2001 present Korean Cancer Association (KCA) Member
2001 present Korean Liver Cancer Study Group (KLCSG) Director of Scientic Board
2001 present Korean Society of Gastroenterology (KSG) Director of Treasury Board

Postgraduate & Social Activities
2001 2003 Korean Society of Gastroenterology Treasurer
2002 2003 Scientific Board, Korean Liver Cancer Study Group (KLCSG) Director
2003 2005 Scientific Committee, Korean Association for the Study of The Liver Chairman
2006 2008 Scientific Committee, 2008 Seoul Meeting of Asian-Pacific Association for the Study of the Liver Chairman
2008 2009 Guideline Committee, 2009 KLCSG-NCC, Korea Practice guidelines for the management of HCC Chairman
2010 2011 Revision Committee, 2011 KASL, Korea Practice guideline for the management of Chronic Hepatitis B Chairman
2012 2013 Guideline Committee, 2013 ILCA practice guideline for the management of intrahepatic cholangiocarcinoma Member
2013 2014 Revision Committee, 2014 KLCSG-NCC, Korea Practice guidelines for the management of HCC Chairman
present Korean Medical Association Treasurer
present Korean Society of Gastroenterology Treasurer
present American Gastroenterological Association (AGA) Treasurer
present American Association for the Study of Liver Diseases (AASLD) Treasurer
present Korean Cancer Association Treasurer
present International Liver Cancer Association (ILCA) Treasurer

Awards
1994 'Young Investigators' award from 10th World Congress of Gastroenterology
1995 'The Best Article of the Year' award from Korean Association of Internal Medicine
1996 'Young Investigators' award from the 10th Asian-Pacific Congress of Gastroenterology
1997 'The Best Article of the Year' award from Korean Society of Gastroenterology