Showing papers presented at "European Workshop on Multi-Agent Systems in 2007"

Virtual Lanes Interest for Motorcycles Simulation

Abstract: Driving simulators are used in many domains such as driving psychology, ergonomics, training. To be the most realistic, a driving simulator needs both good quality of 3D visual rendering and good quality of the associated traffic simulation. This work takes place in the traffic simulation framework, more precisely on the moving level of the motorized two-wheels vehicles. Indeed, these users are not present in the current traffic simulation because of their atypical movings. We support that the environment structured by the road marking is not adapted to the motorcycles. In this article, we propose a model where the motorcyclist dynamically structures the road using virtual lanes built according to the presents actors. The problem of the contra-flow traffic will not be treated here. We offer in particular a lane changing algorithm which allows this kind of vehicle to move efficiently in heavy traffic. Eventually, we validate experimentally our algorithm: we highlight the microscopics characteristics binded to this type of vehicle by comparing real data and results of the simulation.

Simulation as formal and generative social science: the very idea

Abstract: NUNO DAVID, JAIME SIMAO SICHMAN & HELDER COELHO Department of Information Science and Technology, ISCTE Av. das Forcas Armadas, 1649-026 Lisboa, Portugal E-mail: Nuno.David@iscte.pt Computer Engineering Department, University of Sao Paulo Av. Prof. Luciano Gualberto 158 tv.3, 05508-900 Sao Paulo SP Brazil E-mail: Jaime.Sichman@poli.usp.br Faculty of Sciences, University of Lisbon Bloco C5, Piso 1, Campo Grande, 1749-016 Lisboa, Portugal E-mail: hcoelho@di.fc.ul.pt

VCG-based Truthful Mechanisms for Social Task Allocation

Abstract: In many applications of the task allocation problem such as peer-topeer and grid computing, and virtual organizations, the (social or business) relations between the participating agents play an important role, and thus they should be taken into account. Furthermore, in such applications, agents providing the resources usually act self-interested. This paper therefore studies the problem of finding truthful mechanisms for these kinds of social task allocation problems. In this paper we give on the one hand an optimal mechanism and model the problem as an integer linear program (ILP), and on the other hand a polynomialtime approximation by splitting the problem into smaller sub-problems, each of which is solved optimally. We show that both mechanisms are truthful. The optimal mechanism may take exponential time for some instances, and in theory, the quality of the approximation is not guaranteed. However, we show experimentally that for problem instances where the social network has the smallworld property, the quality of the results for the approximation is quite good, due to the fact that the division into subproblems uses the locality of tasks in the social network.