https://purengom.com/2009/12/04/iphone%ec%9d%80-%eb%8d%b0%ec%9d%b4%ed%84%b0-%ed%86%b5%ec%8b%a0%ec%9d%98-%ed%8c%a8%eb%9f%ac%eb%8b%a4%ec%9e%84%ec%9d%84-%eb%b0%94%ea%be%bc%eb%8b%a4/