Book Image

The Reinforcement Learning Workshop

By : Alessandro Palmas, Emanuele Ghelfi, Dr. Alexandra Galina Petre, Mayur Kulkarni, Anand N.S., Quan Nguyen, Aritra Sen, Anthony So, Saikat Basak
Book Image

The Reinforcement Learning Workshop

By: Alessandro Palmas, Emanuele Ghelfi, Dr. Alexandra Galina Petre, Mayur Kulkarni, Anand N.S., Quan Nguyen, Aritra Sen, Anthony So, Saikat Basak

Overview of this book

Various intelligent applications such as video games, inventory management software, warehouse robots, and translation tools use reinforcement learning (RL) to make decisions and perform actions that maximize the probability of the desired outcome. This book will help you to get to grips with the techniques and the algorithms for implementing RL in your machine learning models. Starting with an introduction to RL, youÔÇÖll be guided through different RL environments and frameworks. YouÔÇÖll learn how to implement your own custom environments and use OpenAI baselines to run RL algorithms. Once youÔÇÖve explored classic RL techniques such as Dynamic Programming, Monte Carlo, and TD Learning, youÔÇÖll understand when to apply the different deep learning methods in RL and advance to deep Q-learning. The book will even help you understand the different stages of machine-based problem-solving by using DARQN on a popular video game Breakout. Finally, youÔÇÖll find out when to use a policy-based method to tackle an RL problem. By the end of The Reinforcement Learning Workshop, youÔÇÖll be equipped with the knowledge and skills needed to solve challenging problems using reinforcement learning.
Table of Contents (14 chapters)
Preface
Free Chapter
2
2. Markov Decision Processes and Bellman Equations

RNNs in TensorFlow

In the previous section, we saw how to integrate a CNN into a DQN model to improve the performance of a reinforcement learning agent. We added a few convolutional layers as inputs to the fully connected layers of the DQN model. These convolutional layers helped the model to analyze visual patterns from the game environment and make better decisions.

There is a limitation, however, to using a traditional CNN approach. CNNs can only analyze a single image. While playing video games such as Breakout, analyzing a sequence of images is a much more powerful tool when it comes to understanding the movements of the ball. This is where RNNs come to the fore:

Figure 10.7: Sequencing of RNNs

RNNs are a specific architecture of neural networks that take a sequence of inputs. They are very popular in natural language processing for treating corpora of texts for speech recognition, chatbots, or text translation. Texts can be defined as sequences of...