https://www.syu.ac.kr/blog/2020%eb%85%84-1%ec%9b%94-1%ec%a3%bc%ec%b0%a8-%ec%84%9c%ec%9a%b8%eb%b6%81%eb%b6%80-%ea%b5%ac%ec%9d%b8%ec%a0%95%eb%b3%b4-%ec%95%88%eb%82%b4/%ea%b5%ac%ec%9d%b8%ec%a0%95%eb%b3%b4%ec%84%9c%ec%9a%b8%eb%b6%81%eb%b6%80%ea%b3%a0%ec%9a%a9%ec%84%bc%ed%84%b0-2020-1-8-pdf_page_1/