Lecture slides in DASI spring 2018, National Cheng Kung University, Taiwan. The content is about deep reinforcement learning: policy gradient including variance reduction and importance sampling
Reinforcement Learning 5. Monte Carlo MethodsSeung Jae Lee
A summary of Chapter 5: Monte Carlo Methods of the book 'Reinforcement Learning: An Introduction' by Sutton and Barto. You can find the full book in Professor Sutton's website: http://incompleteideas.net/book/the-book-2nd.html
Check my website for more slides of books and papers!
https://www.endtoend.ai
The lecture slides in DSAI 2018, National Cheng Kung University. It's about famous deep reinforcement learning algorithm: Actor-Critc. In this slides, we introduce advantage function, A3C/A2C.
Dr. Subrat Panda gave an introduction to reinforcement learning. He defined reinforcement learning as dealing with agents that must sense and act upon their environment to receive delayed scalar feedback in the form of rewards. He described key concepts like the Markov decision process framework, value functions, Q-functions, exploration vs exploitation, and extensions like deep reinforcement learning. He listed several real-world applications of reinforcement learning and resources for learning more.
Reinforcement learning:policy gradient (part 1)Bean Yen
The policy gradient theorem is from "Reinforcement Learning : An Introduction". DPG and DDPG is from the original paper.
original link https://docs.google.com/presentation/d/1I3QqfY6h2Pb0a-KEIbKy6v5NuZtnTMLN16Fl-IuNtUo/edit?usp=sharing
Deep Learning: Introduction & Chapter 5 Machine Learning BasicsJason Tsai
Given lecture for Deep Learning 101 study group with Frank Wu on Dec. 9th, 2016.
Reference: https://www.deeplearningbook.org/
Initiated by Taiwan AI Group (https://www.facebook.com/groups/Taiwan.AI.Group/)
1. Reinforcement learning involves an agent learning through trial-and-error interactions with an environment. The agent learns a policy for how to act by maximizing rewards.
2. The document outlines key elements of reinforcement learning including states, actions, rewards, value functions, and explores different methods for solving reinforcement learning problems including dynamic programming, Monte Carlo methods, and temporal difference learning.
3. Temporal difference learning combines the advantages of Monte Carlo methods and dynamic programming by allowing for incremental learning through bootstrapping predictions like dynamic programming while also learning directly from experience like Monte Carlo methods.
발표자: 곽동현(서울대 박사과정, 현 NAVER Clova)
강화학습(Reinforcement learning)의 개요 및 최근 Deep learning 기반의 RL 트렌드를 소개합니다.
발표영상:
http://tv.naver.com/v/2024376
https://youtu.be/dw0sHzE1oAc
This presentation contains an introduction to reinforcement learning, comparison with others learning ways, introduction to Q-Learning and some applications of reinforcement learning in video games.
Reinforcement Learning 5. Monte Carlo MethodsSeung Jae Lee
A summary of Chapter 5: Monte Carlo Methods of the book 'Reinforcement Learning: An Introduction' by Sutton and Barto. You can find the full book in Professor Sutton's website: http://incompleteideas.net/book/the-book-2nd.html
Check my website for more slides of books and papers!
https://www.endtoend.ai
The lecture slides in DSAI 2018, National Cheng Kung University. It's about famous deep reinforcement learning algorithm: Actor-Critc. In this slides, we introduce advantage function, A3C/A2C.
Dr. Subrat Panda gave an introduction to reinforcement learning. He defined reinforcement learning as dealing with agents that must sense and act upon their environment to receive delayed scalar feedback in the form of rewards. He described key concepts like the Markov decision process framework, value functions, Q-functions, exploration vs exploitation, and extensions like deep reinforcement learning. He listed several real-world applications of reinforcement learning and resources for learning more.
Reinforcement learning:policy gradient (part 1)Bean Yen
The policy gradient theorem is from "Reinforcement Learning : An Introduction". DPG and DDPG is from the original paper.
original link https://docs.google.com/presentation/d/1I3QqfY6h2Pb0a-KEIbKy6v5NuZtnTMLN16Fl-IuNtUo/edit?usp=sharing
Deep Learning: Introduction & Chapter 5 Machine Learning BasicsJason Tsai
Given lecture for Deep Learning 101 study group with Frank Wu on Dec. 9th, 2016.
Reference: https://www.deeplearningbook.org/
Initiated by Taiwan AI Group (https://www.facebook.com/groups/Taiwan.AI.Group/)
1. Reinforcement learning involves an agent learning through trial-and-error interactions with an environment. The agent learns a policy for how to act by maximizing rewards.
2. The document outlines key elements of reinforcement learning including states, actions, rewards, value functions, and explores different methods for solving reinforcement learning problems including dynamic programming, Monte Carlo methods, and temporal difference learning.
3. Temporal difference learning combines the advantages of Monte Carlo methods and dynamic programming by allowing for incremental learning through bootstrapping predictions like dynamic programming while also learning directly from experience like Monte Carlo methods.
발표자: 곽동현(서울대 박사과정, 현 NAVER Clova)
강화학습(Reinforcement learning)의 개요 및 최근 Deep learning 기반의 RL 트렌드를 소개합니다.
발표영상:
http://tv.naver.com/v/2024376
https://youtu.be/dw0sHzE1oAc
This presentation contains an introduction to reinforcement learning, comparison with others learning ways, introduction to Q-Learning and some applications of reinforcement learning in video games.
Reinforcement Learning (RL) approaches to deal with finding an optimal reward based policy to act in an environment (Charla en Inglés)
However, what has led to their widespread use is its combination with deep neural networks (DNN) i.e., deep reinforcement learning (Deep RL). Recent successes on not only learning to play games but also superseding humans in it and academia-industry research collaborations like for manipulation of objects, locomotion skills, smart grids, etc. have surely demonstrated their case on a wide variety of challenging tasks.
With application spanning across games, robotics, dialogue, healthcare, marketing, energy and many more domains, Deep RL might just be the power that drives the next generation of Artificial Intelligence (AI) agents!
Slide explaining the distinction between bagging and boosting while understanding the bias variance trade-off. Followed by some lesser known scope of supervised learning. understanding the effect of tree split metric in deciding feature importance. Then understanding the effect of threshold on classification accuracy. Additionally, how to adjust model threshold for classification in supervised learning.
Note: Limitation of Accuracy metric (baseline accuracy), alternative metrics, their use case and their advantage and limitations were briefly discussed.
Reinforcement Learning 4. Dynamic ProgrammingSeung Jae Lee
A summary of Chapter 4: Dynamic Programming of the book 'Reinforcement Learning: An Introduction' by Sutton and Barto. You can find the full book in Professor Sutton's website: http://incompleteideas.net/book/the-book-2nd.html
The document discusses optimization and gradient descent algorithms. Optimization aims to select the best solution given some problem, like maximizing GPA by choosing study hours. Gradient descent is a method for finding the optimal parameters that minimize a cost function. It works by iteratively updating the parameters in the opposite direction of the gradient of the cost function, which points in the direction of greatest increase. The process repeats until convergence. Issues include potential local minimums and slow convergence.
Deep Reinforcement Learning and Its ApplicationsBill Liu
What is the most exciting AI news in recent years? AlphaGo!
What are key techniques for AlphaGo? Deep learning and reinforcement learning (RL)!
What are application areas for deep RL? A lot! In fact, besides games, deep RL has been making tremendous achievements in diverse areas like recommender systems and robotics.
In this talk, we will introduce deep reinforcement learning, present several applications, and discuss issues and potential solutions for successfully applying deep RL in real life scenarios.
https://www.aicamp.ai/event/eventdetails/W2021042818
Reinforcement Learning : A Beginners TutorialOmar Enayet
This document provides an overview of reinforcement learning concepts including:
1) It defines the key components of a Markov Decision Process (MDP) including states, actions, transitions, rewards, and discount rate.
2) It describes value functions which estimate the expected return for following a particular policy from each state or state-action pair.
3) It discusses several elementary solution methods for reinforcement learning problems including dynamic programming, Monte Carlo methods, temporal-difference learning, and actor-critic methods.
Reinforcement learning is a machine learning technique where an agent learns how to behave in an environment by receiving rewards or punishments for its actions. The goal of the agent is to learn an optimal policy that maximizes long-term rewards. Reinforcement learning can be applied to problems like game playing, robot control, scheduling, and economic modeling. The reinforcement learning process involves an agent interacting with an environment to learn through trial-and-error using state, action, reward, and policy. Common algorithms include Q-learning which uses a Q-table to learn the optimal action-selection policy.
Reinforcement Learning In AI Powerpoint Presentation Slide Templates Complete...SlideTeam
Showcase how machines are built to perform intelligent tasks by using our content-ready Reinforcement Learning In AI PowerPoint Presentation Slide Templates Complete Deck. Take advantage of these artificial intelligence PowerPoint visuals, and describe how machine learning models are trained to make sequences of decisions in a complex environment. Showcase the types of artificial intelligence such as deep learning, machine learning. Explain the concept of machine learning which delivers predictive models based on the data fed into machine learning algorithms. Take the assistance of our visually attention-grabbing reinforcement learning PowerPoint templates and discuss the effective uses of artificial intelligence in various areas such as supply chain, human resources, fraud detection, knowledge creation, research, and development, etc. You can also present the usage of AI in healthcare. This includes treatment, diagnosis, training and research, early detection, etc. Explain the working of machine learning by downloading our attention-grabbing supervised learning PowerPoint presentation. https://bit.ly/3kQBnEZ
** AI & Deep Learning with Tensorflow Training: https://www.edureka.co/ai-deep-learning-with-tensorflow **
This Edureka PPT on "Restricted Boltzmann Machine" will provide you with detailed and comprehensive knowledge of Restricted Boltzmann Machines, also known as RBM. You will also get to know about the layers in RBM and their working.
This PPT covers the following topics:
1. History of RBM
2. Difference between RBM & Autoencoders
3. Introduction to RBMs
4. Energy-Based Model & Probabilistic Model
5. Training of RBMs
6. Example: Collaborative Filtering
Follow us to never miss an update in the future.
Instagram: https://www.instagram.com/edureka_learning/
Facebook: https://www.facebook.com/edurekaIN/
Twitter: https://twitter.com/edurekain
LinkedIn: https://www.linkedin.com/company/edureka
Reinforcement learning is a machine learning technique that involves trial-and-error learning. The agent learns to map situations to actions by trial interactions with an environment in order to maximize a reward signal. Deep Q-networks use reinforcement learning and deep learning to allow agents to learn complex behaviors directly from high-dimensional sensory inputs like pixels. DQN uses experience replay and target networks to stabilize learning from experiences. DQN has achieved human-level performance on many Atari 2600 games.
MIT 6.S091: Introduction to Deep Reinforcement Learning (Deep RL) by Lex FridmanPeerasak C.
MIT 6.S091: Introduction to Deep Reinforcement Learning (Deep RL) by Lex Fridman
Watch video: https://youtu.be/zR11FLZ-O9M
First lecture of MIT course 6.S091: Deep Reinforcement Learning, introducing the fascinating field of Deep RL. For more lecture videos on deep learning, reinforcement learning (RL), artificial intelligence (AI & AGI), and podcast conversations, visit our website or follow TensorFlow code tutorials on our GitHub repo.
INFO:
Website: https://deeplearning.mit.edu
CONNECT:
- If you enjoyed this video, please subscribe to this channel.
- Twitter: https://twitter.com/lexfridman
- LinkedIn: https://www.linkedin.com/in/lexfridman
- Facebook: https://www.facebook.com/lexfridman
- Instagram: https://www.instagram.com/lexfridman
Reinforcement Learning 2. Multi-armed BanditsSeung Jae Lee
A summary of Chapter 2: Multi-armed Bandits of the book 'Reinforcement Learning: An Introduction' by Sutton and Barto. You can find the full book in Professor Sutton's website: http://incompleteideas.net/book/the-book-2nd.html
1. Policy gradient methods estimate the optimal policy through gradient ascent on the expected return. They directly learn stochastic policies without estimating value functions.
2. REINFORCE uses Monte Carlo returns to estimate the policy gradient. It updates the policy parameters in the direction of the gradient to maximize expected returns.
3. PPO improves upon REINFORCE by clipping the objective function to restrict how far the new policy can be from the old policy, which helps stabilize training. It uses a surrogate objective and importance sampling to train the policy on data collected from previous policies.
Logistic regression in Machine LearningKuppusamy P
Logistic regression is a predictive analysis algorithm that can be used for classification problems. It estimates the probabilities of different classes using the logistic function, which outputs values between 0 and 1. Logistic regression transforms its output using the sigmoid function to return a probability value. It is used for problems like email spam detection, fraud detection, and tumor classification. The independent variables should be independent of each other and the dependent variable must be categorical. Gradient descent is used to minimize the loss function and optimize the model parameters during training.
The document discusses the Naive REINFORCE algorithm for reinforcement learning. It belongs to the policy gradient class of algorithms. The algorithm works by iteratively updating a neural network policy to maximize the expected reward. It initializes a random policy network, runs episodes to collect rewards and action probabilities, calculates the discounted reward, and backpropagates the error to adjust the policy network weights to increase expected reward over time. Key aspects include directly updating the policy weights via policy gradients without using a value function, which results in slower learning than methods using value functions.
The document discusses various activation functions used in deep learning neural networks including sigmoid, tanh, ReLU, LeakyReLU, ELU, softmax, swish, maxout, and softplus. For each activation function, the document provides details on how the function works and lists pros and cons. Overall, the document provides an overview of common activation functions and considerations for choosing an activation function for different types of deep learning problems.
The document summarizes imitation learning techniques. It introduces behavioral cloning, which frames imitation learning as a supervised learning problem by learning to mimic expert demonstrations. However, behavioral cloning has limitations as it does not allow for recovery from mistakes. Alternative approaches involve direct policy learning using an interactive expert or inverse reinforcement learning, which aims to learn a reward function that explains the expert's behavior. The document outlines different types of imitation learning problems and algorithms for interactive direct policy learning, including data aggregation and policy aggregation methods.
The document discusses multi-armed bandits and their applications. It provides an overview of multi-armed bandits, describing the exploration-exploitation dilemma. It then discusses the optimal UCB algorithm and how it balances exploration and exploitation. Finally, it summarizes two applications of multi-armed bandits: using them for learning to rank in recommendation systems and addressing the cold-start problem in recommender systems.
Continuous Control with Deep Reinforcement Learning, lillicrap et al, 2015Chris Ohk
The paper introduces Deep Deterministic Policy Gradient (DDPG), a model-free reinforcement learning algorithm for problems with continuous action spaces. DDPG combines actor-critic methods with experience replay and target networks similar to DQN. It uses a replay buffer to minimize correlations between samples and target networks to provide stable learning targets. The algorithm was able to solve challenging control problems with high-dimensional observation and action spaces, demonstrating the ability of deep reinforcement learning to handle complex, continuous control tasks.
Modern Recommendation for Advanced Practitioners part2Flavian Vasile
This document summarizes a section on policy learning approaches for recommendation systems. It begins by contrasting policy-based models with value-based models, noting that policy models directly learn a mapping from user states to actions rather than computing value estimates for all actions.
It then introduces concepts in contextual bandits and reinforcement learning, noting that contextual bandits are often a better fit for recommendations since recommendations typically have independent effects. It also discusses using counterfactual risk minimization to address covariate shift in policy learning models by reweighting training data based on logging and target policies.
Finally, it proposes two formulations for contextual bandit models for recommendations - one that directly optimizes a clipped importance sampling objective, and one that optimizes
Intro to Reinforcement learning - part IIMikko Mäkipää
Introduction to Reinforcement Learning, part II: Basic tabular methods
This is the second presentation in a three-part series covering the basics of Reinforcement Learning (RL).
In this presentation, we introduce some more building blocks, such as policy iteration, bandits and exploration, epsilon-greedy policies, temporal difference methods.
We introduce basic model-free methods that use tabular value representation; Monte Carlo on- and off-policy, Sarsa, Expected Sarsa, and Q-learning.
The algorithms are illustrated using simple black jack as an environment.
Reinforcement Learning (RL) approaches to deal with finding an optimal reward based policy to act in an environment (Charla en Inglés)
However, what has led to their widespread use is its combination with deep neural networks (DNN) i.e., deep reinforcement learning (Deep RL). Recent successes on not only learning to play games but also superseding humans in it and academia-industry research collaborations like for manipulation of objects, locomotion skills, smart grids, etc. have surely demonstrated their case on a wide variety of challenging tasks.
With application spanning across games, robotics, dialogue, healthcare, marketing, energy and many more domains, Deep RL might just be the power that drives the next generation of Artificial Intelligence (AI) agents!
Slide explaining the distinction between bagging and boosting while understanding the bias variance trade-off. Followed by some lesser known scope of supervised learning. understanding the effect of tree split metric in deciding feature importance. Then understanding the effect of threshold on classification accuracy. Additionally, how to adjust model threshold for classification in supervised learning.
Note: Limitation of Accuracy metric (baseline accuracy), alternative metrics, their use case and their advantage and limitations were briefly discussed.
Reinforcement Learning 4. Dynamic ProgrammingSeung Jae Lee
A summary of Chapter 4: Dynamic Programming of the book 'Reinforcement Learning: An Introduction' by Sutton and Barto. You can find the full book in Professor Sutton's website: http://incompleteideas.net/book/the-book-2nd.html
The document discusses optimization and gradient descent algorithms. Optimization aims to select the best solution given some problem, like maximizing GPA by choosing study hours. Gradient descent is a method for finding the optimal parameters that minimize a cost function. It works by iteratively updating the parameters in the opposite direction of the gradient of the cost function, which points in the direction of greatest increase. The process repeats until convergence. Issues include potential local minimums and slow convergence.
Deep Reinforcement Learning and Its ApplicationsBill Liu
What is the most exciting AI news in recent years? AlphaGo!
What are key techniques for AlphaGo? Deep learning and reinforcement learning (RL)!
What are application areas for deep RL? A lot! In fact, besides games, deep RL has been making tremendous achievements in diverse areas like recommender systems and robotics.
In this talk, we will introduce deep reinforcement learning, present several applications, and discuss issues and potential solutions for successfully applying deep RL in real life scenarios.
https://www.aicamp.ai/event/eventdetails/W2021042818
Reinforcement Learning : A Beginners TutorialOmar Enayet
This document provides an overview of reinforcement learning concepts including:
1) It defines the key components of a Markov Decision Process (MDP) including states, actions, transitions, rewards, and discount rate.
2) It describes value functions which estimate the expected return for following a particular policy from each state or state-action pair.
3) It discusses several elementary solution methods for reinforcement learning problems including dynamic programming, Monte Carlo methods, temporal-difference learning, and actor-critic methods.
Reinforcement learning is a machine learning technique where an agent learns how to behave in an environment by receiving rewards or punishments for its actions. The goal of the agent is to learn an optimal policy that maximizes long-term rewards. Reinforcement learning can be applied to problems like game playing, robot control, scheduling, and economic modeling. The reinforcement learning process involves an agent interacting with an environment to learn through trial-and-error using state, action, reward, and policy. Common algorithms include Q-learning which uses a Q-table to learn the optimal action-selection policy.
Reinforcement Learning In AI Powerpoint Presentation Slide Templates Complete...SlideTeam
Showcase how machines are built to perform intelligent tasks by using our content-ready Reinforcement Learning In AI PowerPoint Presentation Slide Templates Complete Deck. Take advantage of these artificial intelligence PowerPoint visuals, and describe how machine learning models are trained to make sequences of decisions in a complex environment. Showcase the types of artificial intelligence such as deep learning, machine learning. Explain the concept of machine learning which delivers predictive models based on the data fed into machine learning algorithms. Take the assistance of our visually attention-grabbing reinforcement learning PowerPoint templates and discuss the effective uses of artificial intelligence in various areas such as supply chain, human resources, fraud detection, knowledge creation, research, and development, etc. You can also present the usage of AI in healthcare. This includes treatment, diagnosis, training and research, early detection, etc. Explain the working of machine learning by downloading our attention-grabbing supervised learning PowerPoint presentation. https://bit.ly/3kQBnEZ
** AI & Deep Learning with Tensorflow Training: https://www.edureka.co/ai-deep-learning-with-tensorflow **
This Edureka PPT on "Restricted Boltzmann Machine" will provide you with detailed and comprehensive knowledge of Restricted Boltzmann Machines, also known as RBM. You will also get to know about the layers in RBM and their working.
This PPT covers the following topics:
1. History of RBM
2. Difference between RBM & Autoencoders
3. Introduction to RBMs
4. Energy-Based Model & Probabilistic Model
5. Training of RBMs
6. Example: Collaborative Filtering
Follow us to never miss an update in the future.
Instagram: https://www.instagram.com/edureka_learning/
Facebook: https://www.facebook.com/edurekaIN/
Twitter: https://twitter.com/edurekain
LinkedIn: https://www.linkedin.com/company/edureka
Reinforcement learning is a machine learning technique that involves trial-and-error learning. The agent learns to map situations to actions by trial interactions with an environment in order to maximize a reward signal. Deep Q-networks use reinforcement learning and deep learning to allow agents to learn complex behaviors directly from high-dimensional sensory inputs like pixels. DQN uses experience replay and target networks to stabilize learning from experiences. DQN has achieved human-level performance on many Atari 2600 games.
MIT 6.S091: Introduction to Deep Reinforcement Learning (Deep RL) by Lex FridmanPeerasak C.
MIT 6.S091: Introduction to Deep Reinforcement Learning (Deep RL) by Lex Fridman
Watch video: https://youtu.be/zR11FLZ-O9M
First lecture of MIT course 6.S091: Deep Reinforcement Learning, introducing the fascinating field of Deep RL. For more lecture videos on deep learning, reinforcement learning (RL), artificial intelligence (AI & AGI), and podcast conversations, visit our website or follow TensorFlow code tutorials on our GitHub repo.
INFO:
Website: https://deeplearning.mit.edu
CONNECT:
- If you enjoyed this video, please subscribe to this channel.
- Twitter: https://twitter.com/lexfridman
- LinkedIn: https://www.linkedin.com/in/lexfridman
- Facebook: https://www.facebook.com/lexfridman
- Instagram: https://www.instagram.com/lexfridman
Reinforcement Learning 2. Multi-armed BanditsSeung Jae Lee
A summary of Chapter 2: Multi-armed Bandits of the book 'Reinforcement Learning: An Introduction' by Sutton and Barto. You can find the full book in Professor Sutton's website: http://incompleteideas.net/book/the-book-2nd.html
1. Policy gradient methods estimate the optimal policy through gradient ascent on the expected return. They directly learn stochastic policies without estimating value functions.
2. REINFORCE uses Monte Carlo returns to estimate the policy gradient. It updates the policy parameters in the direction of the gradient to maximize expected returns.
3. PPO improves upon REINFORCE by clipping the objective function to restrict how far the new policy can be from the old policy, which helps stabilize training. It uses a surrogate objective and importance sampling to train the policy on data collected from previous policies.
Logistic regression in Machine LearningKuppusamy P
Logistic regression is a predictive analysis algorithm that can be used for classification problems. It estimates the probabilities of different classes using the logistic function, which outputs values between 0 and 1. Logistic regression transforms its output using the sigmoid function to return a probability value. It is used for problems like email spam detection, fraud detection, and tumor classification. The independent variables should be independent of each other and the dependent variable must be categorical. Gradient descent is used to minimize the loss function and optimize the model parameters during training.
The document discusses the Naive REINFORCE algorithm for reinforcement learning. It belongs to the policy gradient class of algorithms. The algorithm works by iteratively updating a neural network policy to maximize the expected reward. It initializes a random policy network, runs episodes to collect rewards and action probabilities, calculates the discounted reward, and backpropagates the error to adjust the policy network weights to increase expected reward over time. Key aspects include directly updating the policy weights via policy gradients without using a value function, which results in slower learning than methods using value functions.
The document discusses various activation functions used in deep learning neural networks including sigmoid, tanh, ReLU, LeakyReLU, ELU, softmax, swish, maxout, and softplus. For each activation function, the document provides details on how the function works and lists pros and cons. Overall, the document provides an overview of common activation functions and considerations for choosing an activation function for different types of deep learning problems.
The document summarizes imitation learning techniques. It introduces behavioral cloning, which frames imitation learning as a supervised learning problem by learning to mimic expert demonstrations. However, behavioral cloning has limitations as it does not allow for recovery from mistakes. Alternative approaches involve direct policy learning using an interactive expert or inverse reinforcement learning, which aims to learn a reward function that explains the expert's behavior. The document outlines different types of imitation learning problems and algorithms for interactive direct policy learning, including data aggregation and policy aggregation methods.
The document discusses multi-armed bandits and their applications. It provides an overview of multi-armed bandits, describing the exploration-exploitation dilemma. It then discusses the optimal UCB algorithm and how it balances exploration and exploitation. Finally, it summarizes two applications of multi-armed bandits: using them for learning to rank in recommendation systems and addressing the cold-start problem in recommender systems.
Continuous Control with Deep Reinforcement Learning, lillicrap et al, 2015Chris Ohk
The paper introduces Deep Deterministic Policy Gradient (DDPG), a model-free reinforcement learning algorithm for problems with continuous action spaces. DDPG combines actor-critic methods with experience replay and target networks similar to DQN. It uses a replay buffer to minimize correlations between samples and target networks to provide stable learning targets. The algorithm was able to solve challenging control problems with high-dimensional observation and action spaces, demonstrating the ability of deep reinforcement learning to handle complex, continuous control tasks.
Modern Recommendation for Advanced Practitioners part2Flavian Vasile
This document summarizes a section on policy learning approaches for recommendation systems. It begins by contrasting policy-based models with value-based models, noting that policy models directly learn a mapping from user states to actions rather than computing value estimates for all actions.
It then introduces concepts in contextual bandits and reinforcement learning, noting that contextual bandits are often a better fit for recommendations since recommendations typically have independent effects. It also discusses using counterfactual risk minimization to address covariate shift in policy learning models by reweighting training data based on logging and target policies.
Finally, it proposes two formulations for contextual bandit models for recommendations - one that directly optimizes a clipped importance sampling objective, and one that optimizes
Intro to Reinforcement learning - part IIMikko Mäkipää
Introduction to Reinforcement Learning, part II: Basic tabular methods
This is the second presentation in a three-part series covering the basics of Reinforcement Learning (RL).
In this presentation, we introduce some more building blocks, such as policy iteration, bandits and exploration, epsilon-greedy policies, temporal difference methods.
We introduce basic model-free methods that use tabular value representation; Monte Carlo on- and off-policy, Sarsa, Expected Sarsa, and Q-learning.
The algorithms are illustrated using simple black jack as an environment.
The document provides an overview of regression analysis techniques, including linear regression and logistic regression. It explains that regression analysis is used to understand relationships between variables and can be used for prediction. Linear regression finds relationships when the dependent variable is continuous, while logistic regression is used when the dependent variable is binary. The document also discusses selecting the appropriate regression model and highlights important considerations for linear and logistic regression.
This document provides an overview of deep reinforcement learning and related concepts. It discusses reinforcement learning techniques such as model-based and model-free approaches. Deep reinforcement learning techniques like deep Q-networks, policy gradients, and actor-critic methods are explained. The document also introduces decision transformers, which transform reinforcement learning into a sequence modeling problem, and multi-game decision transformers which can learn to play multiple games simultaneously.
How to formulate reinforcement learning in illustrative waysYasutoTamura1
This lecture introduces reinforcement learning and how to approach learning it. It discusses formulating the environment as a Markov decision process and defines important concepts like policy, value functions, returns, and the Bellman equation. The key ideas are that reinforcement learning involves optimizing a policy to maximize expected returns, and value functions are introduced to indirectly evaluate and improve the policy through dynamic programming methods like policy iteration and value iteration. Understanding these fundamental concepts through simple examples is emphasized as the starting point for learning reinforcement learning.
Andrii Prysiazhnyk: Why the amazon sellers are buiyng the RTX 3080: Dynamic p...Lviv Startup Club
Andrii Prysiazhnyk: Why the amazon sellers are buiyng the RTX 3080: Dynamic pricing with RL
AI & BigData Online Day 2021
Website - http://aiconf.com.ua
Youtube - https://www.youtube.com/startuplviv
FB - https://www.facebook.com/aiconf
I had to explain what reinforcement learning (RL) is to my colleagues, in 10 mins.
Given the time and targets, and tried to explain points with as little mathematical notations as possible.
Here’s the slide I used, and you could use it.
Or I’d appreciate some feedbacks.
The theme of the talk simple: you should stop saying “trial and errors” in the beginning of studying RL.
In my opinion the more important point is a value and a policy is updated interactively.
Without this point, you would just get lost in typical RL curriculum, where you start with dynamic programming, Q-learning.
The former is is a RL type without trial and errors, and the latter is a a case where a value and a policy is combined.
Actually other topics like Monte Carlo, TD, function approximation, exploring are crucial, but just options for making RL more diverse.
But anyway I’m also one in a process of studying this.
I’d appreciate feedback on my “study notes.”
https://data-science-blog.com/blog/2021/07/31/my-elaborate-study-notes-on-reinforcement-learning/
SEARN is an algorithm for structured prediction that casts it as a sequence of cost-sensitive classification problems. It works by learning a policy to make incremental decisions that build up the full structured output. The policy is trained through an iterative process of generating cost-sensitive examples from sample outputs produced by the current policy, training a classifier on those examples, and interpolating the new policy with the previous one. This allows SEARN to learn the structured prediction task without requiring assumptions about the output structure, unlike approaches that make independence assumptions or rely on global prediction models.
Reinforcement learning is a machine learning technique that involves an agent learning how to achieve a goal in an environment by trial-and-error using feedback in the form of rewards and punishments. The agent learns an optimal behavior or policy for achieving the maximum reward. Key elements of reinforcement learning include the agent, environment, states, actions, policy, reward function, and value function. Reinforcement learning problems can be solved using methods like dynamic programming, Monte Carlo methods, and temporal difference learning.
Reinforcement Learning Guide For Beginnersgokulprasath06
Reinforcement Learning Guide:
Land in multiple job interviews by joining our Data Science certification course.
Data Science course content designed uniquely, which helps you start learning Data Science from basics to advanced data science concepts.
Content: http://bit.ly/2Mub6xP
Any Queries, Call us@ +91 9884412301 / 9600112302
This document provides an introduction to reinforcement learning. It defines reinforcement learning and compares it to supervised learning. Reinforcement learning involves an agent interacting with an environment and receiving rewards to learn a policy for maximizing rewards. The key elements of reinforcement learning problems are the agent, environment, state, actions, policy, reward function, and value function. The document discusses various reinforcement learning concepts like exploration vs exploitation, temporal difference learning, Q-learning, and Monte Carlo methods. It also compares model-based and model-free reinforcement learning approaches. Overall, the document provides a high-level overview of the main concepts and problem-solving methods in the field of reinforcement learning.
An efficient use of temporal difference technique in Computer Game LearningPrabhu Kumar
This document summarizes an efficient use of temporal difference techniques in computer game learning. It discusses reinforcement learning and some key concepts including the agent-environment interface, types of reinforcement learning tasks, elements of reinforcement learning like policy, reward functions, and value functions. It also describes algorithms like dynamic programming, policy iteration, value iteration, and temporal difference learning. Finally, it mentions some applications of reinforcement learning in benchmark problems, games, and real-world domains like robotics and control.
The document is a seminar report submitted by Kalaissiram S. for their Bachelor of Technology degree. It discusses reinforcement learning (RL), including the key concepts of agents, environments, actions, states, rewards, and policies. It also covers the Bellman equation, types of RL, Markov decision processes, popular RL algorithms like Q-learning and SARSA, and applications of RL.
few common Feature of Size Datum Features are bores, cylinders, slots, or tab...DrPArivalaganASSTPRO
The document discusses feature selection, including its perspectives and aspects. It describes feature selection as a process that chooses an optimal feature subset according to certain criteria to improve performance, visualize data, and reduce dimensionality/noise. The perspectives section outlines different search strategies (exhaustive, heuristic, nondeterministic) and criteria (information measures, distance measures, dependence measures, consistency measures, accuracy measures) used to evaluate feature subsets. The aspects section discusses output types (feature ranking, minimum subsets), evaluation goals (inferability, interpretability, data reduction), and potential drawbacks of feature selection approaches.
This document provides an overview of reinforcement learning concepts. It introduces reinforcement learning as using rewards to learn how to maximize utility. It describes Markov decision processes (MDPs) as the framework for modeling reinforcement learning problems, including states, actions, transitions, and rewards. It discusses solving MDPs by finding optimal policies using value iteration or policy iteration algorithms based on the Bellman equations. The goal is to learn optimal state values or action values through interaction rather than relying on a known model of the environment.
Reinforcement learning (RL) is about finding an optimal policy that maximizes the expected cumulative reward. It works by having an agent interact with an uncertain environment and learn through trial-and-error using feedback in the form of rewards. There are two main learning methods in RL - Monte Carlo which learns from whole episodes and Temporal Difference learning which learns from successive states.
This is the lecture slides in DSAI 2018, National Cheng Kung University. In this slides, we introduce transfer learning and some examples in reinforcement learning. Besides, we also give a brief introduction to curriculum learning.
Lecture slides of DSAI 2018 in National Cheng Kung University.
Reinforcement Learning: Temporal-difference Learning, including Sarsa, Q-learning, n-step bootstrapping, eligibility trace.
This is the lecture slides for DASI spring 2018, National Cheng Kung University.
Deep reinforcement learning presentation about Deep Q Network (DQN) (Nature 2015 version)
Temporal-difference (TD) learning combines ideas from Monte Carlo and dynamic programming methods. It updates estimates based in part on other estimates, like dynamic programming, but uses sampling experiences to estimate expected returns, like Monte Carlo. TD learning is model-free, incremental, and can be applied to continuing tasks. The TD error is the difference between the target value and estimated value, which is used to update value estimates through methods like Sarsa and Q-learning. N-step TD and TD(λ) generalize the idea by incorporating returns and eligibility traces over multiple steps.
- The document discusses the multi-armed bandit problem, which is a simplified decision-making problem used to discuss exploration-exploitation dilemmas in reinforcement learning.
- It provides examples of applying the k-armed bandit problem to recommendation systems, choosing experimental medical treatments, and other scenarios.
- Two methods are introduced for estimating the value of each action: sample-average methods which average rewards over time, and incremental implementations which update estimates online without storing all past rewards.
- Exploration involves selecting non-greedy actions to improve estimates, while exploitation selects the action with the highest estimated value. The ε-greedy policy balances exploration and exploitation.
An introduction to reinforcement learningJie-Han Chen
This document provides an introduction and overview of reinforcement learning. It begins with a syllabus that outlines key topics such as Markov decision processes, dynamic programming, Monte Carlo methods, temporal difference learning, deep reinforcement learning, and active research areas. It then defines the key elements of reinforcement learning including policies, reward signals, value functions, and models of the environment. The document discusses the history and applications of reinforcement learning, highlighting seminal works in backgammon, helicopter control, Atari games, Go, and dialogue generation. It concludes by noting challenges in the field and prominent researchers contributing to its advancement.
Discrete sequential prediction of continuous actions for deep RLJie-Han Chen
This paper proposes a method called SDQN (Sequential Deep Q-Network) to solve continuous action problems using a value-based reinforcement learning approach. SDQN discretizes continuous actions into sequential discrete steps. It transforms the original MDP into an "inner MDP" between consecutive discrete steps and an "outer MDP" between states. SDQN uses two Q-networks - an inner Q-network to estimate state-action values for each discrete step, and an outer Q-network to estimate values between states. It updates the networks using Q-learning for the inner networks and regression to match the last inner Q to the outer Q. The method is tested on a multimodal environment and several MuJoCo tasks, outperform
Deep reinforcement learning from scratchJie-Han Chen
1. The document provides an overview of deep reinforcement learning and the Deep Q-Network algorithm. It defines the key concepts of Markov Decision Processes including states, actions, rewards, and policies.
2. The Deep Q-Network uses a deep neural network as a function approximator to estimate the optimal action-value function. It employs experience replay and a separate target network to stabilize learning.
3. Experiments applying DQN to the Atari 2600 game Space Invaders are discussed, comparing different loss functions and optimizers. The standard DQN configuration with MSE loss and RMSProp performed best.
The document describes a multi-agent reinforcement learning framework called BiCNet that allows agents to learn coordination strategies for combat games like StarCraft. BiCNet uses an actor-critic architecture with two bidirectional RNNs to model agent collaboration. It introduces individual rewards and a vectorized policy gradient to train agents. Evaluation shows BiCNet agents outperform rule-based and other RL baselines by learning strategies like focus firing, hit-and-run tactics, and coordinated attacks between heterogeneous units.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
-------------------------------------------------------------------------------
Find out more about ISO training and certification services
Training: ISO/IEC 27001 Information Security Management System - EN | PECB
ISO/IEC 42001 Artificial Intelligence Management System - EN | PECB
General Data Protection Regulation (GDPR) - Training Courses - EN | PECB
Webinars: https://pecb.com/webinars
Article: https://pecb.com/article
-------------------------------------------------------------------------------
For more information about PECB:
Website: https://pecb.com/
LinkedIn: https://www.linkedin.com/company/pecb/
Facebook: https://www.facebook.com/PECBInternational/
Slideshare: http://www.slideshare.net/PECBCERTIFICATION
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
2. Some content and images in this slides were borrowed from:
1. Sergey Levine’s Deep Reinforcement Learning class in UCB
2. David Silver’s Reinforcement Learning class in UCL
3. Rich Sutton’s textbook
4. Deep Reinforcement Learning and Control in CMU (CMU 10703)
2
Disclaimer
4. Value-based Reinforcement Learning
In previous lecture, we introduce how to use neural network to approximate value
function and how to learn the optimal policy in discrete action space.
6. Value-based Reinforcement Learning
● The optimal policy learned from value-based method is deterministic
● It’s hard to be applied in continuous action problem
7. Pitfall of Value-based Reinforcement Learning
Consider the following simple maze, the features are constructed by 4 elements
and each element means whether facing the wall in that direction (N, S, W, E).
feature: (1, 1, 0, 0)
8. Pitfall of Value-based Reinforcement Learning
For deterministic policy:
● It will move east either or west in both grey states.
● It may get stuck and never reach the goal state.
9. Pitfall of Value-based Reinforcement Learning
Although well-defined observation could help the agent to distinguish the
difference in different states, sometimes we prefer to use stochastic policy.
10. Pitfall of Value-based Reinforcement Learning
In robotics, the action(control) is often continuous. We
need to decide the degree/torque in the robotic arm
given observation.
It’s hard to use argmax to demonstrate the optimal
action of robotic arm, so we need other solutions in
continuous control problem.
11. Value-based and Policy-based RL
Value-Based
● Learnt Value Function
● Implicit policy
Policy-Based
● No Value Function
● Learnt Policy
Actor-Critic
● Learnt Value Function
● Learnt Policy
12. Policy Gradient
The objective of reinforcement learning is to maximize the expected episodic
rewards (here, we take episodic task as our example)
We define as and is represented for the episodic trajectory,
the objective can be expressed as following:
28. Features of Policy-Based RL
Advantages
● Better convergence
● Effective in high-dimensional or continuous action space
● Stochastic policy
Disadvantages:
● Local optimal rather than global optimal
● Inefficient learning (learned by episodes)
● High variance
29. REINFORCE: bias and variance
The estimator is unbiased, because it use true
rewards to evaluate policy.
The estimator of REINFORCE is known to have
high variance because of huge difference in
episodic rewards. High variance results in slow
convergence.
40. Variance reduction: baseline
*baseline is independent of policy
Reduce variance with baseline won’t make model biased, as long as the
baseline is independent of the policy (not action-related)
41. Variance reduction: baseline
● Subtracting a baseline is unbiased in expectation, It won’t make the
estimator biased.
● The baseline can be any function, random variable, as long as it does
not vary with action.
42. Variance reduction: baseline
Variance:
Related Paper:
VARIANCE REDUCTION FOR POLICY GRADIENT WITH ACTION-DEPENDENT FACTORIZED
BASELINES, Cathy Wu*, Aravind Rajeswaran*, Yan Duan, Vikash Kumar, Alexandre M Bayen, Sham Kakade, Igor
Mordatch, Pieter Abbeel OpenAI (currently under review at ICLR 2018)
43. Variance reduction: causality + baseline
In previous, we introduce 2 method to reduce variance.
● Causality
● Baseline
Question: Can we combine two variance reduction method together?
44. Variance reduction: causality + baseline
The ideal form:
Terminal state
Staring state
If you are in certain state of trajectory, there are many potential
path to reach different terminal state. Of course, the remaining
rewards would also be different.
The naive concept is to find the average remaining rewards in
that state, in other words, value function.
The state in trajectory
45. Variance reduction: causality + baseline
We can learn value function by the method mentioned before
(tabular method or using function approximator)
In REINFORCE algorithm, the agent play with environment
until reaching terminal state. We know the remaining rewards
at each step so that we can use Monte Carlo method to
evaluate policy, and the loss could be MSE.
46. Policy
Policy Gradient can be apply to discrete action space problem so as continuous
action space problem.
● Discrete action problem: Softmax Policy
● Continuous action problem: Gaussian Policy
47. Policy: Softmax Policy
Here, we suppose the function approximator is h(s, a) and is its parameters
we will sample the action according to its softmax probability.
observation
(features)
action
probability
48. Policy: Gaussian Policy
In continuous control, a Gaussian policy is common.
● Gaussian distribution:
● Gaussian Policy: we use neural network to approximate mean, and sample the
action according to Gaussian distribution. The variance can also be
parameterized.
49. Policy: Gaussian Policy
Here, we use fixed variance and mean value is computed by linear combination of
state features, where is used to features transformation.
The gradient of the log of the policy is
In neural network, you just need to backpropagate the sampled action probability.
50. Reason of Inefficient Learning
The main reasons for inefficient learning in REINFORCE are:
● The REINFORCE algorithm is on-policy
● We need to learning by Monte-Carlo method
51. Reason of Inefficient Learning
The main reasons for inefficient learning in REINFORCE are:
● The REINFORCE algorithm is on-policy
The learning process of REINFORCE:
1. Sample multiple trajectories from
2. Fit model
If the sampled trajectories are from different distribution, the
learning result would be wrong.
52. Reason of Inefficient Learning
The main reason for inefficient learning in REINFORCE is:
● The REINFORCE algorithm is on-policy
● We need to learning by Monte-Carlo method
○ In vanilla policy gradient, we sample multiple trajectories but just update model once. In
contrast to TD learning, vanilla policy gradient learns much slower.
53. Reason of Inefficient Learning
The main reason for inefficient learning in REINFORCE is:
● The REINFORCE algorithm is on-policy
● We need to learning by Monte-Carlo method
Improve by importance sampling
Improve by Actor-Critic
54. Importance sampling
Importance sampling is a statistical technique that we could use to estimate the
properties from different distribution here.
Suppose the objective is , but the data are sampled from q(X), we
can do such transformation:
Objective of on-policy policy gradient :
Objective of off-policy policy gradient:
55. Off-policy & importance sampling
● target policy ( ): the learning policy, which we are interested in.
● behavior policy ( ): the policy used to collect samples.
We sample the trajectories from the objective would be:
56. Off-policy & importance sampling
● target policy ( ): the learning policy, which we are interested in.
● behavior policy ( ): the policy used to collect samples.
We sample the trajectories from the objective would be:
57. Off-policy & importance sampling
● target policy ( ): the learning policy, which we are interested in.
● behavior policy ( ): the policy used to interact with environment.
We sample the trajectories from the objective would be:
Importance sampling ratio
ends up depending only on
the two policies and the
sequence.
58. Off-policy & importance sampling
Suppose the off-policy objective function is:
target policy (learner neural net)
behavior policy (expert/behavior neural net)
63. Off-policy & importance sampling
The gradient of off-policy objective:
future action won’t affect current weight
64. Off-policy & importance sampling
The gradient of off-policy objective:
1. This is the general form of off-policy policy gradient. if we
use on-policy learning, the form is as same as vanilla policy
gradient (importance sampling ratio is 1)
2. In practice, We store trajectories along with its action
probability each step, and then update the neural network
by adding importance sampling ratio.
65. Reason of Inefficient Learning
The main reason for inefficient learning in REINFORCE is:
● The REINFORCE algorithm is on-policy
● We need to learning by Monte-Carlo method
We’ve already discussed.
In the next section
66. Reference
● CS 294, Berkeley lecture 4: http://rll.berkeley.edu/deeprlcourse/
● David Silver RL course lecture7: http://www0.cs.ucl.ac.uk/staff/d.silver/web/Teaching_files/pg.pdf
● Baseline Substraction from Shan-Hung Wu https://www.youtube.com/watch?v=XnXRzOB0Pc8
● Andrej Karpathy’s blog: http://karpathy.github.io/2016/05/31/rl/
● Policy Gradient in pytorch https://github.com/pytorch/examples/tree/master/reinforcement_learning
67. Outline
● Pitfall of Value-based Reinforcement Learning
○ Value-based policy is deterministic
○ Hard to handle continuous control
● Policy gradient
● Variance reduction
○ Causality
○ Baseline
● Policy in policy gradient
○ Softmax policy
○ Gaussian policy
● Off-policy policy gradient
○ Importance sampling