• Post Doctorate Fellow & Physician, Obesity Research Center, Columbia Unviersity, NY, USA
• Post Doctorate Fellow of Laparoscopic Obesity Surgery, St Luke’s Roosebelt Hospital of Columbia University, NY, USA
• Exchange Professor, Ariake Hospital, Japan
• Served as Adjunct Professor, Youido St. Mary’s Hospital Catholic University of Korea
• Official Member, Society of American Gastrointestinal and Endoscopic Surgeons
• Official Member, American Society for Metabolic and Bariatric Surgery
• Secretary & Academic Director, Korean Research Association of Obesity Metabolic Surgery
• Director, Korean Society of Obesity and Health
• Official Member, Korean Surgical Society
• Official Member, the Korean Society of Endoscopic & Laparoscopic Surgeons