Machine Learning, Homework 9, Neural NetsApril 15, 2019ContentsBoston Housing with a Single Layer and R package nnet 1Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Digit Recognition wit…

1. Feedforward and cost function; 2.Regularized cost function: 3.Sigmoid gradient The gradient for the sigmoid function can be computed as: where: 4.Random initialization randInitializeWeights.m function W = randInitializeWeights(L_in, L_out) %RANDIN…

1. advantage: when number of features is too large, so previous algorithm is not a good way to learn complex nonlinear hypotheses. 2. representation "activation" of unit i in layer j matrix of weights controlling function mapping from layer j to…

引子 对于一个特征数比较大的非线性分类问题,如果采用先前的回归算法,需要很多相关量和高阶量作为输入,算法的时间复杂度就会很大,还有可能会产生过拟合问题,如下图: 这时就可以选择采用神经网络算法. 神经网络算法最早是人们希望模仿大脑的学习功能而想出来的. 一个神经元,有多个树突(Dendrite)作为信息的输入通道,也有多个轴突(Axon)作为信息的输出通道.一个神经元的输出可以作为另一个神经元的输入.神经元的概念和多分类问题的分类器概念很相近,都是可以接收多个输入,在不同的权值(weights)…

About this Course You will learn how to build a successful machine learning project. If you aspire to be a technical leader in AI, and know how to set direction for your team's work, this course will show you how. Much of this content has never been…

What is machine learning? One area of technology that is helping improve the services that we use on our smartphones, and on the web, is machine learning. Sometimes, the terms machine learning and artificial intelligence get used as synonyms, especia…

The human visual system is one of the wonders of the world. Consider the following sequence of handwritten digits: Most people effortlessly recognize those digits as 504192. That ease is deceptive. In each hemisphere of our brain, humans have a prima…

Problems[show] Classification Clustering Regression Anomaly detection Association rules Reinforcement learning Structured prediction Feature engineering Feature learning Online learning Semi-supervised learning Unsupervised learning Learning to rank…

Lecture 11 — Hopfield Nets Lecture 12 — Boltzmann machine learning Ref: 能量模型(EBM).限制波尔兹曼机(RBM) 高大上的模型和理论. Hopfield Nets 看了能量函数,发现: These look very much like the weights and biases of a neural network. [点到为止] Boltzmann machine learning From: A Beginne…

Link: Neural Networks for Machine Learning - 多伦多大学 Link: Hinton的CSC321课程笔记1 Link: Hinton的CSC321课程笔记2 一年后再看课程,亦有收获,虽然看似明白,但细细推敲其实能挖掘出很多深刻的内容:以下为在线课程以及该笔记的课程重难点总结. Lecture 01 增强学习: (这是ng的拿手好戏,他做无人直升机可是做了好久)增强学习的输出是一个动作或者一系列的动作,通过与实际的场合下的环境互动来决定动作,增强学习的…