https://www.syu.ac.kr/grad/2011%eb%85%84-%ed%9b%84%ea%b8%b0-%ec%8b%a0%ec%9e%85%ec%83%9d-%ec%b6%94%ea%b0%80%eb%aa%a8%ec%a7%91-%eb%a9%b4%ec%a0%91-%ec%9e%a5%ec%86%8c-%ec%95%88%eb%82%b4/