https://www.syu.ac.kr/irb/2018/12/14/%ec%97%b0%ea%b5%ac%ec%9e%90%eb%a5%bc-%ec%9c%84%ed%95%9c-%ec%a7%88%eb%b3%91%ea%b4%80%eb%a6%ac%eb%b3%b8%eb%b6%80-%ea%b8%b0%ea%b4%80%ec%83%9d%eb%aa%85%ec%9c%a4%eb%a6%ac%ec%9c%84%ec%9b%90%ed%9a%8c/