https://github.com/KerasKorea/KEKOxTutorial/blob/master/22_Keras%EB%A5%BC%20%ED%99%9C%EC%9A%A9%ED%95%9C%20%EC%A3%BC%EC%8B%9D%20%EA%B0%80%EA%B2%A9%20%EC%98%88%EC%B8%A1.md
https://github.com/KerasKorea/KEKOxTutorial/blob/master/22_Keras%EB%A5%BC%20%ED%99%9C%EC%9A%A9%ED%95%9C%20%EC%A3%BC%EC%8B%9D%20%EA%B0%80%EA%B2%A9%20%EC%98%88%EC%B8%A1.md