AutoEncoder
https://qiita.com/shinmura0/items/ee074172ec3c818b614e
https://speakerdeck.com/katsunoriohnishi/variational-auto-encoderru-men
https://catindog.hatenablog.com/entry/2018/07/29/172210
https://blog.amedama.jp/entry/keras-auto-encoder
https://blog.amedama.jp/entry/keras-cnn-auto-encoder