https://purengom.com/2009/11/05/iphone%ec%9d%b4-%ea%b2%bd%ec%b0%a9%eb%a5%99-%ed%95%a0-%ec%88%98%eb%b0%96%ec%97%90-%ec%97%86%eb%8a%94-%ea%b9%8c%eb%8b%ad%ec%9d%80/