第四周:深层神经网络(Deep Neural Networks) 深层神经网络(Deep L-layer neural network) 目前为止我们学习了只有一个单独隐藏层的神经网络的正向传播和反向传播,还有逻辑回归,并且你还学到了向量化,这在随机初始化权重时是很重要.本周所要做的是把这些理念集合起来,就可以执行你自己的深度神经网络. 严格上来说逻辑回归也是一个一层的神经网络,浅与深仅仅是指一种程度.有一个隐藏层的神经网络,就是一个两层神经网络.当我们算神经网络的层数时,我们不算输入层,我们只…

第三周:浅层神经网络(Shallow neural networks) 神经网络概述(Neural Network Overview) 本周你将学习如何实现一个神经网络.在我们深入学习具体技术之前,我希望快速的带你预览一下本周你将会学到的东西.如果在本节课中的某些细节你没有看懂你也不用担心,我们将在后面的几节课中深入讨论技术细节. 现在我们开始快速浏览一下如何实现神经网络.首先你需要输入特征 \(x​\),参数 \(w​\) 和 \(b​\),通过这些你就可以计算出 \(z​\),接下来使用 \…

NN representation 这一课主要是讲3层神经网络 下面是常见的 activation 函数.sigmoid, tanh, ReLU, leaky ReLU. Sigmoid 只用在输出0/1 时候的output layer, 其他情况基本不用,因为tanh 总是比sigmoid 好. 两种 ReLU 使用起来总是要比sigmoid 和 tanh 快.ReLU 是最常用的 activation. 为什么Activation function 要是non-linear的?因为如下图所示…

Logistic regression Cost function for logistic regression Gradient Descent 接下来主要讲 Vectorization Logistic Regression 的向量实现 Vectorizing LR Gradient output Python/Numpy and Jupyter Notebook 上图中 axis=0 表示竖直方向,axis=1 是水平方向…

When a golf player is first learning to play golf, they usually spend most of their time developing a basic swing. Only gradually do they develop other shots, learning to chip, draw and fade the ball, building on and modifying their basic swing. In a…

Andrew Ng deeplearning courese-4:Convolutional Neural Network Convolutional Neural Networks: Step by Step Convolutional Neural Networks: Application Residual Networks Autonomous driving - Car detection YOLO Face Recognition for the Happy House Art: N…

Andrew Ng deeplearning courese-4:Convolutional Neural Network Convolutional Neural Networks: Step by Step Convolutional Neural Networks: Application Residual Networks Autonomous driving - Car detection YOLO Face Recognition for the Happy House Art: N…

ON THE EVOLUTION OF MACHINE LEARNING: FROM LINEAR MODELS TO NEURAL NETWORKS We recently interviewed Reza Zadeh (@Reza_Zadeh). Reza is a Consulting Professor in the Institute for Computational and Mathematical Engineering at Stanford University and a…

NEURAL NETWORKS, PART 1: BACKGROUND Artificial neural networks (NN for short) are practical, elegant, and mathematically fascinating models for machine learning. They are inspired by the central nervous systems of humans and animals – smaller process…

Must Know Tips/Tricks in Deep Neural Networks (by Xiu-Shen Wei)   Deep Neural Networks, especially Convolutional Neural Networks (CNN), allows computational models that are composed of multiple processing layers to learn representations of data with…