反向传播算法 Backpropagation Algorithm 假设我们有一个固定样本集 ,它包含 个样例。我们可以用批量梯度下降法来求解神经网络。具体来讲,对于单个样例(x,y),其代价函数为: 这是一个(二分之一的)方差代价函数。给定一个包含 个样例的数据集,我们可以定义整体代价函数为: 以上公式中的第一项 是一个均方差项。第...
本文直接举一个例子,带入数值演示反向传播法的过程,公式的推导等到下次写Auto-Encoder的时候再写,其实也很简单,感兴趣的同学可以自己推导下试试:)(注:本文假设你已经懂得基本的神经网络构成,如果完全不懂,可以参考Poll写的笔记:[Mechine Learning & Algorithm] 神经网络基础) 假设,你有这样一个网络层: 第一层是输...
项目github地址:bitcarmanlee easy-algorithm-interview-and-practice 虽然学深度学习有一段时间了,但是对于一些算法的具体实现还是模糊不清,用了很久也不是很了解。因此特意先对深度学习中的相关基础概念做一下总结。先看看前向传播算法(Forward propagation)与反向传播算法(Back propagation)。 1.前向传播 如图所示,这里...
Learn the Backpropagation Algorithms in detail, including its definition, working principles, and applications in neural networks and machine learning.
The capabilities of natural neural systems have inspired both new generations of machine learning algorithms as well as neuromorphic, very large-scale integrated circuits capable of fast, low-power information processing. However, it has been argued that
As we have demonstrated here, by using a well-defined set of neuronal and neural circuit mechanisms, it is possible to implement the backpropagation algorithm on contemporary neuromorphic hardware. Previously proposed methods to address the issues outlined in the Introduction were not on their own ab...
During learning, the brain modifies synapses to improve behaviour. In the cortex, synapses are embedded within multilayered networks, making it difficult to determine the effect of an individual synaptic modification on the behaviour of the system. The backpropagation algorithm solves this problem in ...
神经网络(5)-MLP网络及Back Propagation Algorithm MLP-多层感知器即反向传播算法 1. Introduction 2. **函数 2.1 Sigmoid Function 2.2 Hyperbolic Tangent: 2.3 Muti-Layer Perceptrons 的网络架构及输出 2.4 MLP 网络的功能(Representive Power) 2. Back propagation 2.1 Introduction 2.2 Alg... ...
希望能对读者理解神经网络的反向传播有一定的帮助Further readingHow the backpropagation algorithm works.A...
Back-Propagation Algorithm 又称为误差反向传播算法。它是神经网络两个计算流中的一个,另一个是前向传递。 前向传递定义了一个优化好的神经网络具体计算的过程。 而误差反向传播算法则定义了神经网络优化的方向。 接下来,我们来详细推导一下神经网络如何根据已有的信息进行优化,即误差反向传播。