이론: https://dot-daffodil-0e4.notion.site/Chapter2-b7868e7911e34b23ad762843bf077a94 실습: https://github.com/Justion1234/Deep_Learning_From_Scratch_02/blob/main/%EB%B0%91%EB%B0%94%EB%8B%A5%EB%B6%80%ED%84%B0_%EC%8B%9C%EC%9E%91%ED%95%98%EB%8A%94_%EB%94%A5%EB%9F%AC%EB%8B%9D_1_2.ipynb