https://zhuanlan.zhihu.com/p/71882757
https://www.julyedu.com/question/big/kp_id/26/ques_id/1032
https://blog.csdn.net/hjimce/article/details/50414467 (maxout的讲解，容易易懂)https://www.jianshu.com/p/9879bdce0a60 （softplus,relu的平滑版本）https://zhuanlan.zhihu.com/p/71882757
https://www.julyedu.com/question/big/kp_id/26/ques_id/1032
https://blog.csdn.net/hjimce/article/details/50414467 (maxout的讲解，容易易懂)https://www.jianshu.com/p/9879bdce0a60 （softplus,relu的平滑版本）