https://www.syu.ac.kr/sw/2015%eb%85%84-%ec%9e%ac%ec%a0%95%ed%8c%a8%eb%84%90-%ed%95%99%ec%88%a0%eb%8c%80%ed%9a%8c-%eb%8c%80%ed%95%99%ec%9b%90%ec%83%9d-%eb%85%bc%eb%ac%b8%ea%b2%bd%ec%a7%84-%eb%8c%80%ed%9a%8c/