https://www.syu.ac.kr/blog/2021-1-%ec%b7%a8%ec%97%85%ec%a7%84%eb%a1%9c%ea%b5%90%ea%b3%bc%eb%aa%a9-%ec%95%88%eb%82%b4ncs-%ec%a7%81%ec%97%85%ea%b8%b0%ec%b4%88%eb%8a%a5%eb%a0%a5%ec%9d%98-%ec%9d%b4%ed%95%b4/%ec%a0%9c%eb%aa%a9%ec%9d%84-%ec%9e%85%eb%a0%a5%ed%95%b4%ec%a3%bc%ec%84%b8%ec%9a%94-_001/