Short Communication
Minjoon Yu
Abstract
The human body has a circadian rhythm according to the repetitive daily biological cycle. This is essential for survival, but the quality of life can depends on its change. It can also be called a biological regulation factor, and it is now known that the biological clock is used for physiological functions (e.g. body temperature, hormone synthesis and sleep-arousal cycle) and psychological functions (e.g. cognitive functions and memory power). A biological rhythm, which is a diurnal 24 h cycle, shows a difference in behavior and vital functions, depending on the day-night change.