https://www.syu.ac.kr/blog/2021%ed%95%99%eb%85%84%eb%8f%84-2%ed%95%99%ea%b8%b0-%ed%95%9c%ea%b5%ad%eb%b0%a9%ec%86%a1%ed%86%b5%ec%8b%a0%eb%8c%80%ed%95%99%ea%b5%90-%ec%83%9d%ed%99%9c%ec%b2%b4%ec%9c%a1%ec%a7%80%eb%8f%84%ea%b3%bc/%ec%83%9d%ed%99%9c%ec%b2%b4%ec%9c%a1%ec%a7%80%eb%8f%84%ea%b3%bc-%ec%9e%85%ec%8b%9c-%eb%a6%ac%ed%94%8c%eb%a6%bf-pdf_page_1/