https://www.syu.ac.kr/rnd/2019%eb%85%84-%ec%9e%ac%eb%82%9c%ec%95%88%ec%a0%84-rd%ec%82%ac%ec%97%85-%ed%98%84%ec%9e%a5%eb%8c%80%ec%9d%91%eb%b6%80%ec%b2%98-%ed%95%a9%eb%8f%99%ec%84%a4%eb%aa%85%ed%9a%8c-%ec%95%88%eb%82%b4/