Department of Internal Medicine;
Pusan National University School of Medicine;
Biomedical Research Institute;
Pusan National University Hospital;
Busan 602-739;
South Korea;
Department of Internal Medicine;
Ulsan University Hospital;
University of Ulsan College of Medicine;
Ulsan 682-714;
South Korea;
Division of Gastroenterology;
Department of Medicine;
University of Washington;
Seattle;
WA 98104;
United States;
Endoscopic; ultrasonography; Training; Phantom; Computer; simulation; Animal; model;