The presented framework is the The multirobot coalition formation problem seeks to intelligently first to leverage a conceptual clustering technique to partition partition a team of heterogeneous robots into any set of coalition formation algorithms in order to derive coalitions for a set of real-world tasks. Besides being N Pan optimal hierarchy classification tree, given any classification complete (Sandholm et al. 1999), the problem is also hard taxonomy. The results contribute to the state-ofthe-art to approximate (Service and Adams 2011a). Traditional approaches in multiagent systems by demonstrating the existence to solving the problem include a number of greedy of crucial patterns and intricate relationships among existing algorithms (Shehory and Kraus 1998; Vig and Adams coalition algorithms.

In Reinforcement Learning, it is common to use optimistic initialization of value functions to encourage exploration. However, such an approach generally depends on the domain, viz., the scale of the rewards must be known, and, when using function approximation, the feature representation must have a constant norm. We present a simple approach that performs optimistic initialization with less dependence on the domain.

Atari 2600 games are deterministic given a fixed policy leading to a fixed sequence of actions. This article investigates three methods for adding randomness: random initialization, epsilon-greedy action selection, and epislon-repeat action selection. These methods are evaluated by how well they are able to derail a memorizing agent without hurting the performance of a randomized agent. Results indicate that epsilon-repeat action selection best fits the desired criteria and lower values of epsilon than previously used are sufficient to derail the memorizing agent.

We carry out an empirical study of classification-based policy iteration (CBPI) in a simplified Markovian Decision Process (MDP). In this simple MDP, we expose some pathological cases where variance in state-action value estimates can degrade the performance of CBPI to the point of complete ineffectiveness. In particular, it is shown that with enough variance in the returns, e.g., if we estimate state-action values with a single rollout, CBPI drifts away from the/an optimal policy over iterations, even when the optimal policy is its initial policy to iterate over. From our investigation we also arrived at a natural cost-sensitive classification problem where the costs are noisy, a problem which to the best of our knowledge has not been studied in the classification literature.

In this paper we consider a scenario where one or more robotic bodyguards are protecting an important individual (VIP) moving in a public space against harassment or harm from unarmed civilians. In this scenario, the main objective of the robots is to position themselves such that at any given moment they provide maximum physical cover for the VIP. The robots need to follow the VIP in its movement and take into account the movements of the civilians as well. The environment can also contain obstacles which present challenges to movement but also provide natural cover. We designed two algorithms for the movement of the bodyguard robots: Threat Vector Resolution (TVR) for a single robot and Quadrant Load Balancing (QLB) for teams of bodyguard robots. We evaluated the proposed approaches against rigid formations in a simulation study.

Understanding trust, influence and reputation and constructing computational models of these notions are two essential scientific challenges in computer science as well as social sciences. Although scientists in both disciplines have independently conducted research on these topics over the last couple of decades, there is a huge gap between two literatures. This paper therefore illustrates an interdisciplinary work-in-progress on trust, influence and reputation modeling based on human reasoning. Using a survey-based data collection approach, we would like to understand how humans gain/lose trust in their daily life interactions and how behavior/attitudes of humans can be influenced or shaped in various social encounters. The data will be then transformed into mathematical models to be used in technological or software systems.

We consider a strategic variant of the facility location problem. We would like to locate a facility on a closed interval. There are n agents located on that interval, divided into two types: type 1 agents, who wish for the facility to be as far from them as possible, and type 2 agents, who wish for the facility to be as close to them as possible. Our goal is to maximize a form of aggregated social benefit: maxisum– the sum of the agents’ utilities, or the egalitarian objective– the minimal agent utility. The strategic aspect of the problem is that the agents’ locations are not known to us, but rather reported to us by the agents– an agent might misreport his location in an attempt to move the facility away from or towards to his true location. We therefore require the facility-locating mechanism to be strategyproof, namely that reporting truthfully is a dominant strategy for each agent. As simply maximizing the social benefit is generally not strategyproof, our goal is to design strategyproof mechanisms with good approximation ratios. In this paper, we provide a best-possible 3approximate deterministic strategyproof mechanism, as well as a 23/13 approximate randomized strategyproof mechanism, both for the maxisum objective. We provide lower bounds of 3 and 3/2 on the approximation ratio attainable for maxisum, in the deterministic and randomized settings, respectively. For the egalitarian objective, we show that no bounded approximation ratio is attainable in the deterministic setting, and provide a lower bound of 3/2 for the randomized setting. To obtain our deterministic lower bounds, we characterize all deterministic strategyproof mechanisms when all agents are of type 1. Finally, while still restricting ourselves to agents of type 1 only, we consider a generalized model that allows an agent to control more than one location. In this generalized model, we provide best-possible 3and 3 approximate strategyproof 2 mechanisms for the maxisum objective in the deterministic and randomized settings, respectively.

We propose a novel online learning method for minimizing regret in large extensive-form games. The approach learns a function approximator online to estimate the regret for choosing a particular action. A no-regret algorithm uses these estimates in place of the true regrets to define a sequence of policies. We prove the approach sound by providing a bound relating the quality of the function approximation and regret of the algorithm. A corollary being that the method is guaranteed to converge to a Nash equilibrium in self-play so long as the regrets are ultimately realizable by the function approximator. Our technique can be understood as a principled generalization of existing work on abstraction in large games; in our work, both the abstraction as well as the equilibrium are learned during self-play. We demonstrate empirically the method achieves higher quality strategies than state-of-the-art abstraction techniques given the same resources.

Contract bridge is an example of an incomplete information game for which computers typically do not perform better than expert human bridge players. In particular, the typical bidding decisions of human bridge players are difficult to mimic with a computer program, and thus automatic bridge bidding remains to be a challenging research problem. Currently, the possibility of automatic bidding without mimicking human players has not been fully studied. In this work, we take an initiative to study such a possibility for the specific problem of bidding without competition. We propose a novel learning framework to let a computer program learn its own bidding decisions. The framework transforms the bidding problem into a learning problem, and then solves the problem with a carefully designed model that consists of cost-sensitive classifiers and upper-confidence-bound algorithms. We validate the proposed model and find that it performs competitively to the champion computer bridge program that mimics human bidding decisions.

The leading approach for solving large imperfect-information games is automated abstraction followed by running an equilibrium-finding algorithm. We introduce a distributed version of the most commonly used equilibrium-finding algorithm, counterfactual regret minimization (CFR), which enables CFR to scale to dramatically larger abstractions and numbers of cores. The new algorithm begets constraints on the abstraction so as to make the pieces running on different computers disjoint. We introduce an algorithm for generating such abstractions while capitalizing on state-of-the-art abstraction ideas such as imperfect recall and earth-mover's distance. Our techniques enabled an equilibrium computation of unprecedented size on a supercomputer with a high inter-blade memory latency. Prior approaches run slowly on this architecture. Our approach also leads to a significant improvement over using the prior best approach on a large shared-memory server with low memory latency. Finally, we introduce a family of post-processing techniques that outperform prior ones. We applied these techniques to generate an agent for two-player no-limit Texas Hold'em that won the 2014 Annual Computer Poker Competition, beating each opponent with statistical significance.