Reinforcement Learning
Discovering Options for Exploration by Minimizing Cover Time
Jinnai, Yuu, Park, Jee Won, Abel, David, Konidaris, George
Finding a set of edges that minimizes expected One of the main challenges in reinforcement learning cover time is an extremely hard combinatorial optimization is solving tasks with sparse reward. We show problem (Braess, 1968; Braess et al., 2005). Thus, our that the difficulty of discovering a distant rewarding algorithm instead seeks to minimize the upper bound of the state in an MDP is bounded by the expected expected cover time given as a function of the algebraic cover time of a random walk over the graph induced connectivity of the graph Laplacian (Fiedler, 1973; Broder by the MDP's transition dynamics. We & Karlin, 1989; Chung, 1996) using the heuristic method therefore propose to accelerate exploration by constructing by Ghosh & Boyd (2006) that improves the upper bound of options that minimize cover time. The the expected cover time of a uniform random walk.
Online Antenna Tuning in Heterogeneous Cellular Networks with Deep Reinforcement Learning
Balevi, Eren, Andrews, Jeffrey G.
We aim to jointly optimize the antenna tilt angle, and the vertical and horizontal half-power beamwidths of the macrocells in a heterogeneous cellular network (HetNet) via a synergistic combination of deep learning (DL) and reinforcement learning (RL). The interactions between the cells, most notably due to their coupled interference and the large number of users, renders this optimization problem prohibitively complex. This makes the proposed deep RL technique attractive as a practical online solution for real deployments, which should automatically adapt to new base stations being added and other environmental changes in the network. In the proposed algorithm, DL is used to extract the features by learning the locations of the users, and mean field RL is used to learn the average interference values for different antenna settings. Our results illustrate that the proposed deep RL algorithm can approach the optimum weighted sum rate with hundreds of online trials, as opposed to millions of trials for standard Q-learning, assuming relatively low environmental dynamics. Furthermore, the proposed algorithm is compact and implementable, and empirically appears to provide a performance guarantee regardless of the amount of environmental dynamics.
AI2-THOR: An Interactive 3D Environment for Visual AI
Kolve, Eric, Mottaghi, Roozbeh, Han, Winson, VanderBilt, Eli, Weihs, Luca, Herrasti, Alvaro, Gordon, Daniel, Zhu, Yuke, Gupta, Abhinav, Farhadi, Ali
We introduce The House Of inteRactions (THOR), a framework for visual AI research, available at http://ai2thor.allenai.org. AI2-THOR consists of near photo-realistic 3D indoor scenes, where AI agents can navigate in the scenes and interact with objects to perform tasks. AI2-THOR enables research in many different domains including but not limited to deep reinforcement learning, imitation learning, learning by interaction, planning, visual question answering, unsupervised representation learning, object detection and segmentation, and learning models of cognition. The goal of AI2-THOR is to facilitate building visually intelligent models and push the research forward in this domain.
Atari-HEAD: Atari Human Eye-Tracking and Demonstration Dataset
Zhang, Ruohan, Liu, Zhuode, Guan, Lin, Zhang, Luxin, Hayhoe, Mary M, Ballard, Dana H
Additionally, previous research has shown that and eye movements while playing Atari videos games. The given a task context, human visual attention is modulated dataset currently has 44 hours of gameplay data from 16 by reward [5, 9, 17]. In performing a familiar task, objects games and a total of 2.97 million demonstrated actions. Human with high potential reward or penalty attracts human attention subjects played games in a frame-by-frame manner to hence gaze indicates the momentary attentional priorities allow enough decision time in order to obtain near-optimal over multiple objects. Therefore the gaze could be a decisions. This dataset could be potentially used for research potentially useful intermediate learning signal for imitation in imitation learning, reinforcement learning, and learning.
A Review of Reinforcement Learning for Autonomous Building Energy Management
Mason, Karl, Grijalva, Santiago
The area of building energy management has received a significant amount of interest in recent years. This area is concerned with combining advancements in sensor technologies, communications and advanced control algorithms to optimize energy utilization. Reinforcement learning is one of the most prominent machine learning algorithms used for control problems and has had many successful applications in the area of building energy management. This research gives a comprehensive review of the literature relating to the application of reinforcement learning to developing autonomous building energy management systems. The main direction for future research and challenges in reinforcement learning are also outlined.
Successive Over Relaxation Q-Learning
Kamanchi, Chandramouli, Diddigi, Raghuram Bharadwaj, Bhatnagar, Shalabh
In a discounted reward Markov Decision Process (MDP) the objective is to find the optimal value function, i.e., the value function corresponding to an optimal policy. This problem reduces to solving a functional equation known as the Bellman equation and a fixed point iteration scheme known as the value iteration is utilized to obtain the solution. In [1], a successive over-relaxation based value iteration scheme is proposed to speed up the computation of the optimal value function. They propose a modified Bellman equation and prove faster convergence to the optimal value function. However, in many practical applications, the model information is not known and we resort to Reinforcement Learning (RL) algorithms to obtain optimal policy and value function. One such popular algorithm is Q-Learning. In this paper, we propose Successive Over Relaxation (SOR) Q-Learning. We first derive a fixed point iteration for optimal Q-values based on [1] and utilize stochastic approximation to derive a learning algorithm to compute the optimal value function and an optimal policy. We then prove the convergence of the SOR Q-Learning to optimal Q-values. Finally, through numerical experiments, we show that SOR Q-Learning is faster compared to the standard Q-Learning algorithm.
Adaptive Variance for Changing Sparse-Reward Environments
Lin, Xingyu, Guo, Pengsheng, Florensa, Carlos, Held, David
Robots that are trained to perform a task in a fixed environment often fail when facing unexpected changes to the environment due to a lack of exploration. We propose a principled way to adapt the policy for better exploration in changing sparse-reward environments. Unlike previous works which explicitly model environmental changes, we analyze the relationship between the value function and the optimal exploration for a Gaussian-parameterized policy and show that our theory leads to an effective strategy for adjusting the variance of the policy, enabling fast adapt to changes in a variety of sparse-reward environments.
Can Robot Attract Passersby without Causing Discomfort by User-Centered Reinforcement Learning?
Ozaki, Yasunori, Ishihara, Tatsuya, Matsumura, Narimune, Nunobiki, Tadashi
The aim of our study was to develop a method by which a social robot can greet passersby and get their attention without causing them to suffer discomfort.A number of customer services have recently come to be provided by social robots rather than people, including, serving as receptionists, guides, and exhibitors. Robot exhibitors, for example, can explain products being promoted by the robot owners. However, a sudden greeting by a robot can startle passersby and cause discomfort to passersby.Social robots should thus adapt their mannerisms to the situation they face regarding passersby.We developed a method for meeting this requirement on the basis of the results of related work. Our proposed method, user-centered reinforcement learning, enables robots to greet passersby and get their attention without causing them to suffer discomfort (p<0.01) .The results of an experiment in the field, an office entrance, demonstrated that our method meets this requirement.
Contextual Markov Decision Processes using Generalized Linear Models
We consider the recently proposed reinforcement learning (RL) framework of Contextual Markov Decision Processes (CMDP), where the agent has a sequence of episodic interactions with tabular environments chosen from a possibly infinite set. The parameters of these environments depend on a context vector that is available to the agent at the start of each episode. In this paper, we propose a no-regret online RL algorithm in the setting where the MDP parameters are obtained from the context using generalized linear models (GLMs). The proposed algorithm \texttt{GL-ORL} relies on efficient online updates and is also memory efficient. Our analysis of the algorithm gives new results in the logit link case and improves previous bounds in the linear case. Our algorithm uses efficient Online Newton Step updates to build confidence sets. Moreover, for any strongly convex link function, we also show a generic conversion from any online no-regret algorithm to confidence sets.
Deep Reinforcement Learning with Feedback-based Exploration
Scholten, Jan, Wout, Daan, Celemin, Carlos, Kober, Jens
Deep Reinforcement Learning has enabled the control of increasingly complex and high-dimensional problems. However, the need of vast amounts of data before reasonable performance is attained prevents its widespread application. We employ binary corrective feedback as a general and intuitive manner to incorporate human intuition and domain knowledge in model-free machine learning. The uncertainty in the policy and the corrective feedback is combined directly in the action space as probabilistic conditional exploration. As a result, the greatest part of the otherwise ignorant learning process can be avoided. We demonstrate the proposed method, Predictive Probabilistic Merging of Policies (PPMP), in combination with DDPG. In experiments on continuous control problems of the OpenAI Gym, we achieve drastic improvements in sample efficiency, final performance, and robustness to erroneous feedback, both for human and synthetic feedback. Additionally, we show solutions beyond the demonstrated knowledge.