1. Department of Surgery, National Health Insurance Service Ilsan Hospital, Goyang, Republic of Korea
2. Department of Anesthesiology, Yonsei University College of Medicine, Seoul, Republic of Korea
3. Department of Biostatistics, Anne Consulting, Seoul, Republic of Korea
4. Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea
5. Gastric Cancer Center, Yonsei Cancer Center, Yonsei University Health System, Seoul, Republic of Korea
6. Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.