Cosmic radiation exposure of the flight crews in Korea has been managed by Radiation Safety Management around Living Life Act under Nuclear and Security Commission. However, domestic are excluded from because relatively low route dose compared to that international crews. But we found accumulated total annual is far negligible long time too many flights. In this study, suggest necessity managem...

Looking at the current technology of water skiing equipment, it isn’t hard to trace its roots. Ralph Samuelson successfully skied on Lake Pepin in Lake City, MN in 1922. He was the first recorded person to water ski. His skis consisted of two pine boards with leather bindings (Winkler, 2009). From this modest beginning came the old style flat bottomed and square tailed skis that were standard f...