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The University of Liverpool’s Department of Computer Science continues to demonstrate world excellence in the field of Artificial Intelligence, and in particular, Agents and Multi-Agent Systems, by winning the Best Paper Award for two years running at the prestigious AAMAS conference.
In 2008, the paper, co-authored by Paul, Wiebe and Michael, in collaboration with Sarit Kraus of Bar Ilan University, Israel, was selected from 721 papers submitted to the conference.
This year, the award winning paper was written by Wiebe and Michael in collaboration with Thomas Ågotnes (Bergen University College, Norway) and Moshe Tennenholtz (Microsoft Israel R&D Center & Technion–Israel Institute of Technology, Israel), and was selected from 651 papers submitted to the 2009 conference.
The Autonomous Agents and Multiagent Systems Conference (AAMAS) is the leading scientific conference for research in autonomous agents and Multiagent systems. The AAMAS conference series was initiated in 2002 by merging highly respected individual conferences:
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•The International Conference on Multi-Agent Systems (ICMAS);
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•The International Workshop on Agent Theories, Architectures, and Languages (ATAL);
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•The International Conference on Autonomous Agents (AA).
The aim of the joint conference is to provide a single, high-profile, internationally respected archival forum for scientific research in the theory and practice of autonomous agents and multiagent systems.
Photo courtesy of Wiebe van der Hoek
Liverpool wins AAMAS Best Paper Award for 2nd Year Running
18/05/2009
2009 AAMAS Best Paper Award
Thomas Ågotnes, Wiebe van der Hoek, Moshe Tennenholtz, and Michael Wooldridge. Power in Normative Systems. Proceedings of the 8th International Conference on Autonomous Agents and Multi-Agent Systems (AAMAS-2009). Budapest, Hungary, May 2009.
Power indices such as the Banzhaf index were originally developed within voting theory in an attempt to rigourously characterise the influence that a voter is able to wield in a particular voting game. In this paper, we show how such power indices can be applied to understanding the relative importance of agents when we attempt to devise a co-ordination mechanism using the paradigm of social laws, or normative systems. Understanding how pivotal an agent is with respect to the success of a particular social law is of benefit when designing such social laws: we might typically aim to ensure that power is distributed evenly amongst the agents in a system, to avoid bottlenecks or single points of failure. After formally defining the framework and illustrating the role of power indices in it, we investigate the complexity of computing these indices, showing that the characteristic complexity result is #P-completeness. We then investigate cases where computing indices is computationally easy.
2008 AAMAS Best Paper Award
Paul E. Dunne, Wiebe van der Hoek, Sarit Kraus, and Michael Wooldridge, Cooperative Boolean games. Proceedings of the 7th International Conference on Autonomous Agents and Multiagent Systems (AAMAS-2008). Estoril, Portugal, May, 2008
We present and formally investigate Cooperative Boolean Games, a new, natural family of coalitional games that are both compact and expressive. In such a game, an agent’s primary aim is to achieve its individual goal, which is represented as a propositional logic formula over some set of Boolean variables. Each agent is assumed to exercise unique control over some subset of the overall set of Boolean variables, and the set of valuations for these variables corresponds to the set of actions the agent can take. However, the actions available to an agent are assumed to have some cost, and an agent’s secondary aim is to minimise its costs. Typically, an agent must cooperate with others because it does not have sufficient control to ensure its goal is satisfied. However, the desire to minimise costs leads to preferences over possible coalitions, and hence to strategic behaviour. Following an introduction to the formal framework of Cooperative Boolean Games, we investigate solution concepts of the core and stable sets for them. In each case, we characterise the complexity of the associated solution concept, and discuss the surrounding issues. Finally, we present a bargaining protocol for cooperation in Boolean games, and characterise the strategies in equilibrium for this protocol.