Book Image

Advanced Deep Learning with Keras

By : Rowel Atienza
Book Image

Advanced Deep Learning with Keras

By: Rowel Atienza

Overview of this book

Recent developments in deep learning, including Generative Adversarial Networks (GANs), Variational Autoencoders (VAEs), and Deep Reinforcement Learning (DRL) are creating impressive AI results in our news headlines - such as AlphaGo Zero beating world chess champions, and generative AI that can create art paintings that sell for over $400k because they are so human-like. Advanced Deep Learning with Keras is a comprehensive guide to the advanced deep learning techniques available today, so you can create your own cutting-edge AI. Using Keras as an open-source deep learning library, you'll find hands-on projects throughout that show you how to create more effective AI with the latest techniques. The journey begins with an overview of MLPs, CNNs, and RNNs, which are the building blocks for the more advanced techniques in the book. You’ll learn how to implement deep learning models with Keras and TensorFlow 1.x, and move forwards to advanced techniques, as you explore deep neural network architectures, including ResNet and DenseNet, and how to create autoencoders. You then learn all about GANs, and how they can open new levels of AI performance. Next, you’ll get up to speed with how VAEs are implemented, and you’ll see how GANs and VAEs have the generative power to synthesize data that can be extremely convincing to humans - a major stride forward for modern AI. To complete this set of advanced techniques, you'll learn how to implement DRL such as Deep Q-Learning and Policy Gradient Methods, which are critical to many modern results in AI.
Table of Contents (13 chapters)

The Q value

An important question is that if the RL problem is to find The Q value, how does the agent learn by interacting with the environment? Equation 9.1.3 does not explicitly indicate the action to try and the succeeding state to compute the return. In RL, we find that it's easier to learn The Q value by using the Q value:

The Q value (Equation 9.2.1)


The Q value (Equation 9.2.2)

In other words, instead of finding the policy that maximizes the value for all states, Equation 9.2.1 looks for the action that maximizes the quality (Q) value for all states. After finding the Q value function, V* and hence The Q value are determined by Equation 9.2.2 and 9.1.3 respectively.

If for every action, the reward and the next state can be observed, we can formulate the following iterative or trial and error algorithm to learn the Q value:

The Q value (Equation 9.2.3)

For notational simplicity, both s ' and a ' are the next state and action respectively. Equation 9.2.3 is known as the Bellman Equation which is the core...