https://www.syu.ac.kr/rnd/2020%eb%85%84%eb%8f%84-%ec%a0%9c1%ec%b0%a8-%eb%b0%b1%ec%8b%a0%ec%8b%a4%ec%9a%a9%ed%99%94%ea%b8%b0%ec%88%a0%ea%b0%9c%eb%b0%9c%ec%82%ac%ec%97%85%eb%8b%a8-%ec%8b%a0%ea%b7%9c%ec%a7%80%ec%9b%90-%eb%8c%80-3/