Industry
Guardian: A Crowd-Powered Spoken Dialog System for Web APIs
Huang, Ting-Hao Kenneth (Carnegie Mellon University) | Lasecki, Walter S. (University of Michigan) | Bigham, Jeffrey P. (Carnegie Mellon University)
Natural language dialog is an important and intuitive way for people to access information and services. However, current dialog systems are limited in scope, brittle to the richness of natural language, and expensive to produce. This paper introduces Guardian, a crowd-powered framework that wraps existing Web APIs into immediately usable spoken dialog systems. Guardian takes as input the Web API and desired task, and the crowd determines the parameters necessary to complete it, how to ask for them, and interprets the responses from the API. The system is structured so that, over time, it can learn to take over for the crowd. This hybrid systems approach will help make dialog systems both more general and more robust going forward.
Reliable Aggregation of Boolean Crowdsourced Tasks
Alfaro, Luca de (University of California, Santa Cruz) | Polychronopoulos, Vassilis (University of California, Santa Cruz) | Shavlovsky, Michael (University of California, Santa Cruz)
We propose novel algorithms for the problem of crowdsourcing binary labels. Such binary labeling tasks are very common in crowdsourcing platforms, for instance, to judge the appropriateness of web content or to flag vandalism. We propose two unsupervised algorithms: one simple to implement albeit derived heuristically, and one based on iterated bayesian parameter estimation of user reputation models. We provide mathematical insight into the benefits of the proposed algorithms over existing approaches, and we confirm these insights by showing that both algorithms offer improved performance on many occasions across both synthetic and real-world datasets obtained via Amazon Mechanical Turk.
Assistive Technologies for People With Cognitive Disabilities: Challenges and Possibilities
Sayko, Madelaine Elizabeth (Cognitive Compass) | Tremoulet, Patrice (Cognitive Compass)
According to the Journal, Inclusion, in 2012, 9% of the US population, or 28.5M Americans, had a cognitive disability. Worldwide the number is believed to exceed 630 million. This is a very heterogeneous group, with a wide variety of abilities and impairments making it challenging to develop assistive technologies to meet their needsA growing sub-set of this cohort is the aging population, who continue to work but experience mild cognitive changes. Though these these individuals have deep funds of knowledge, and valuable skills they may struggle in the workplace, in part due to lack of access to tools that can address their individual challenges. . The development of new technologies, such as cognitive assistants, has opened the door to more useful solutions. This paper will review the history and challenges of assistive technology for cognition (ATC) and highlight the work in which we are currently engaged.
A Game with a Purpose for Recommender Systems
Smyth, Barry (University College Dublin) | Rafter, Rachael (University College Dublin) | Banks, Sam (University College Dublin)
Recommender systems learn about our preferences to make targeted suggestions. In this paper we outline a novel game-with-a-purpose designed to infer preferences at scale as a side-effect of gameplay. We evaluate the utility of this data in a recommendation context as part of a small live-user trial.
Online Transfer Learning in Reinforcement Learning Domains
Zhan, Yusen (Washington State University) | Taylor, Mattew E. (Washington State University)
This paper proposes an online transfer framework to capture the interaction among agents and shows that current transfer learning in reinforcement learning is a special case of online transfer. Furthermore, this paper re-characterizes existing agents-teaching-agents methods as online transfer and analyze one such teaching method in three ways. First, the convergence of Q-learning and Sarsa with tabular representation with a finite budget is proven. Second, the convergence of Q-learning and Sarsa with linear function approximation is established. Third, the we show the asymptotic performance cannot be hurt through teaching. Additionally, all theoretical results are empirically validated.
Autonomous Electricity Trading Using Time-Of-Use Tariffs in a Competitive Market
Urieli, Daniel (The University of Texas at Austin) | Stone, Peter (The University of Texas at Austin)
This research studies the impact of Time-Of-Use (TOU) tariffs in a competitive electricity market place. Specifically, it focuses on the question of how should an autonomous broker agent optimize TOU tariffs in a competitive retail market, and what is the impact of such tariffs on the economy. We formalize the problem of TOU tariff optimization and propose an algorithm for approximating its solution. We extensively experiment with our algorithm in a large-scale, detailed electricity retail markets simulation of the Power Trading Agent Competition (Power TAC) and: 1) find that our algorithm results in 15\% peak-demand reduction, 2) find that its peak-flattening results in greater profits and/or profit-share for the broker and allows it to win in head-to-head competition against the 1st and 2nd place brokers from the Power TAC 2014 finals, and 3) analyze several economic implications of using TOU tariffs in competitive retail markets.
Exploiting Anonymity in Approximate Linear Programming: Scaling to Large Multiagent MDPs
Robbel, Philipp (Massachusetts Institute of Technology) | Oliehoek, Frans A. (University of Amsterdam) | Kochenderfer, Mykel J. (Stanford University)
The Markov Decision Process (MDP) framework is a versatile method for addressing single and multiagent sequential decision making problems. Many exact and approximate solution methods attempt to exploit structure in the problem and are based on value factorization. Especially multiagent settings (MAS), however, are known to suffer from an exponential increase in value component sizes as interactions become denser, meaning that approximation architectures are overly restricted in the problem sizes and types they can handle. We present an approach to mitigate this limitation for certain types of MASs, exploiting a property that can be thought of as "anonymous influence" in the factored MDP. In particular, we show how anonymity can lead to representational and computational efficiencies, both for general variable elimination in a factor graph but also for the approximate linear programming solution to factored MDPs. The latter allows to scale linear programming to factored MDPs that were previously unsolvable. Our results are shown for a disease control domain over a graph with 50 nodes that are each connected with up to 15 neighbors.
Open Questions for Building Optimal Operation Policies for Dam Management Using Factored Markov Decision Processes
Reyes, Alberto (Instituto de Investigaciones Electricas) | Ibarguengoytia, Pablo H. (Instituto de Investigaciones Electricas) | Romero, Inรฉs (Instituto de Investigaciones Electricas) | Pech, David (Instituto de Investigaciones Electricas) | Borunda, Mรณnica (Instituto de Investigaciones Electricas)
In this paper, we present the conceptual model of a realworld application of Markov Decision Processes to dam management. The idea is to demonstrate that it is possible to efficiently automate the construction of operation policies by modelling the problem as a sequential decision problem that can be easily solved using stochastic dynamic programming. We will explain the problem domain and provide an analysis of the resulting value and policy functions. We will also present a useful discussion about the issues that will appear when the conceptual model to be extended into a real-world application.
Deep Recurrent Q-Learning for Partially Observable MDPs
Hausknecht, Matthew (University of Texas at Austin) | Stone, Peter (University of Texas at Austin)
Deep Reinforcement Learning has yielded proficient controllers for complex tasks. However, these controllers have limited memory and rely on being able to perceive the complete game screen at each decision point. To address these shortcomings, this article investigates the effects of adding recurrency to a Deep Q-Network (DQN) by replacing the first post-convolutional fully-connected layer with a recurrent LSTM. The resulting Deep Recurrent Q-Network (DRQN), although capable of seeing only a single frame at each timestep, successfully integrates information through time and replicates DQN's performance on standard Atari games and partially observed equivalents featuring flickering game screens. Additionally, when trained with partial observations and evaluated with incrementally more complete observations, DRQN's performance scales as a function of observability. Conversely, when trained with full observations and evaluated with partial observations, DRQN's performance degrades less than DQN's. Thus, given the same length of history, recurrency is a viable alternative to stacking a history of frames in the DQN's input layer and while recurrency confers no systematic advantage when learning to play the game, the recurrent net can better adapt at evaluation time if the quality of observations changes.
Probabilistic Planning for Decentralized Multi-Robot Systems
Amato, Christopher (University of New Hampshire) | Konidaris, George (Duke University) | Omidshafiei, Shayegan (Massachusetts Institute of Technology) | Agha-mohammadi, Ali-akbar (Qualcomm Research) | How, Jonathan P. (Massachusetts Institute of Technology) | Kaelbling, Leslie P. (Massachusetts Institute of Technology)
Multi-robot systems are an exciting application domain for AI research and Dec-POMDPs, specifically. MacDec-POMDP methods can produce high-quality general solutions for realistic heterogeneous multi-robot coordination problems by automatically generating control and communication policies, given a model. In contrast to most existing multi-robot methods that are specialized to a particular problem class, our approach can synthesize policies that exploit any opportunities for coordination that are present in the problem, while balancing uncertainty, sensor information, and information about other agents.