Book Image

Hands-On Neural Networks with Keras

By : Niloy Purkait
Book Image

Hands-On Neural Networks with Keras

By: Niloy Purkait

Overview of this book

Neural networks are used to solve a wide range of problems in different areas of AI and deep learning. Hands-On Neural Networks with Keras will start with teaching you about the core concepts of neural networks. You will delve into combining different neural network models and work with real-world use cases, including computer vision, natural language understanding, synthetic data generation, and many more. Moving on, you will become well versed with convolutional neural networks (CNNs), recurrent neural networks (RNNs), long short-term memory (LSTM) networks, autoencoders, and generative adversarial networks (GANs) using real-world training datasets. We will examine how to use CNNs for image recognition, how to use reinforcement learning agents, and many more. We will dive into the specific architectures of various networks and then implement each of them in a hands-on manner using industry-grade frameworks. By the end of this book, you will be highly familiar with all prominent deep learning models and frameworks, and the options you have when applying deep learning to real-world scenarios and embedding artificial intelligence as the core fabric of your organization.
Table of Contents (16 chapters)
Free Chapter
1
Section 1: Fundamentals of Neural Networks
5
Section 2: Advanced Neural Network Architectures
10
Section 3: Hybrid Model Architecture
13
Section 4: Road Ahead

Exploding and vanishing gradients

Backpropagating the model's errors in a deep neural network, however, comes with its own complexities. This holds equally true for RNNs, facing their own versions of the vanishing and exploding gradient problem. As we discussed earlier, the activation of neurons in a given time step is dependent on the following equation:

at = tanH [ (W x t ) + (Waa x a(t-1)) + ba ]

We saw how Wax and Waa are two separate weight matrices that the RNN layers share through time. These matrices are multiplied to the input matrix at current time, and the activation from the previous time step, respectively. The dot products are then summed up, along with a bias term, and passed through a tanh activation function to compute the activation of neurons at current time (t). We then used this activation matrix to compute the predicted output at current time (), before...