1. Division of Colorectal Surgery, Department of Surgery, Dongnam Institute of Radiological and Medical Sciences, Busan, Korea.
2. RexSoft Corporation, Seoul, Korea.
3. Institute of Health and Environment, Seoul National University, Seoul, Korea.
4. Department of Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
5. Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.