AGENTS VIC Meeting
Friday, 25 September 2009 @ 9:30AM.
Coffee, tea and refreshments from 9:15.
University of Melbourne, Rm 5.08, ICT Building (Dept of CSSE), 111 Barry St.
Eduardo Gomes, Swinburne University
Dynamic Analysis of Multiagent Q-learning with e-greedy Exploration
The development of mechanisms to understand and model the expected behaviour of multiagent learners is becoming increasingly important as the area rapidly find application in a variety of domains. In this paper we present a framework to model the behaviour of Q-learning agents using the e-greedy exploration mechanism. For this, we analyse a continuous-time version of the Q-learning update rule and study how the presence of other agents and the e-greedy mechanism affect it. We then model the problem as a system of difference equations which is used to theoretically analyse the expected behaviour of the agents. The applicability of the framework is tested through experiments in typical games selected from the literature.
Golriz Rezaie
Evolving Cooperation in the N-player Prisoner's Dilemma: A Social Network Model
We introduce a social network based model to investigate the evolution of cooperation in the N-player prisoner's dilemma game. Agents who play cooperatively form social links, which are reinforced by subsequent cooperative actions. Agents tend to interact with players from their social network. However, when an agent defects, the links with its opponents in that game are broken. We examine two different scenarios: (a) where all agents are equipped with a pure strategy, and (b) where some agents play with a mixed strategy. In the mixed case, agents base their decision on a function of the weighted links within their social network. Detailed simulation experiments show that the proposed model is able to promote cooperation. Social networks play an increasingly important role in promoting and sustaining cooperation in the mixed strategy case. An analysis of the emergent social networks shows that they are characterized by high average clustering and broad-scale.
