Modèles formels pour la reproduction des simulations à base d’agents

Du fait de la dimension expérimentale des résultats obtenus par simulation informatique, la validation de ces résultats nécessite qu’ils puissent être reproduits. Cela suppose que le dispositif concret à partir desquels ils sont obtenus, à savoir le logiciel dont les exécutions fournissent les sorties qui sont observées, puisse donner lieu à de nouvelles implantations. Bien qu’elle soit indispensable à maints égards, il s’avère que cette “réplication” des modèles de simulation est le plus souvent problématique; cet article propose de présenter ces modèles sous la forme de systèmes afin d’en faciliter de nouvelles implantations.Since the results obtained by means of computer-based simulations have an experimental character, their validation requests their reproduction. These results are obtained by observing the outputs of the runs of a software entity, which is the concrete device of the experimentation; thus, it is this software simulation model that must support a new implementation. Although the replication of a model brings many advantages, in many cases it is problematic. This paper proposes to present simulation models as systems, to ease their replication

Quand des sociologues rencontrent des informaticiens : essai de formalisation, méta-modélisation, modélisation et simulation des systèmes d’action concrets

Le texte résulte d’une collaboration inédite entre sociologues et informaticiens. Il présente un travail de formalisation de la sociologie de l’action organisée qui a abouti à l’élaboration d’un méta-modèle de cette théorie. Ce méta-modèle permet de modéliser des systèmes d’action concrets et de simuler leur fonctionnement. A travers l’exposition des résultats théoriques et leur application à un cas simple, nous souhaitons montrer que cette démarche présente un intérêt théorique et méthodologique pour la sociologie. Elle permet de préciser des concepts sociologiques initialement exprimés en langage naturel afin de pouvoir les évaluer de manière quantitative. Elle rend possible la simulation de situations organisationnelles et ouvre ainsi la voie à une exploration des états possibles d’un système d’action concret. Ces éléments constituent, à nos yeux, un enrichissement de la pratique sociologique.The text results from a new collaboration between sociologists and data processing specialists. It presents a work of formalization of the sociology of organized action which led to the development of a meta-model of this theory. This meta-model makes it possible to model concrete systems of action and to simulate their operation. Through the exposure of the theoretical results and their application to a simple case, we wish to show that this step is of theoretical and methodological interest for sociology. It makes it possible to specify sociological concepts initially expressed in natural language in order to be able to evaluate them in a quantitative way. It makes possible the simulation of organisational situations and thus opens the way with an exploration of the possible states of a concrete system of action. These elements constitute, from our point of view, an enrichment of the sociological practice

Data Analysis of Social Simulations Outputs - Focus on variables dispersion

International audienceIn the domain of social simulation, there are very few papers reporting on the statistical analysis of simulation results, while it is very common in empirical social sciences. The paper advocates the expansion of the statistical analysis of social simulation outputs, as a very efficient way to improve the interpretation of simulation results and so the understanding of the system that is the model's target. This is illustrated by the study of a simulation model designed to analyze a real situation related to the management of a river in South West of France. Several standard statistics methods are used to shed light on the possible outcomes of the discussion between the actors

Boundedly Rational Agents Playing the Social Actors Game - How to reach cooperation

International audienceIn any organizational setting, each of the participating actors adopts a quite steady behavior with respect to others. This behavior is not always in line with what might be expected given the role of the actor, although it is quite cooperative and most often contributes significantly to the proper operation of the organization. Within the framework of the SocLab approach for the modeling and analysis of organizations, we propose a model of the bounded rationality that social actors could implement in the process yielding the joint adaptation of their behaviors

HIGH LEVEL PETRI NETS WITH DATA STRUCTURE

International audienceFor the lack of a data structure, Petri nets are not suitable for modeling systems such as Information Systems, where data have an effect on the system's behavior. In the High Level Petri Nets we set out here, tokens are replaced by entities which are described by means of a model closely related to those of the Database Theory. In order to take into account the values of entities, a precondition and an action may be associated to each transition. This data structure allows to define new nets' properties, which are analyzed by Program Theory techniques, whereas a lot of results provided by linear algebra remain valid. In addition, computation of invariants may be done

The Efficiency of Organizational Withdrawal vs Commitment

National audienceActors within an organization usually do not behave as expected at design-time. There are diverse reasons for this, notably the actors' motivation and organizational commitment. In this paper, we explore the efficiency of a concrete public organization in the context of the Latin-American culture, to the light of the organizational commitment of its members. In order to evaluate how much each member of the organization is committed, we associate to each one a parameter that quantifies its commitment and we evaluate by simulation the impact of this parameter on its behavior an the organization performance. With a model of the organization as it was intended to operate at its foundation, we proceed to a number of simulations to find the parameter values that yield the actual observed working of the organization. By the way, we found that withdrawn behaviors have much more impact than committed ones

A market-oriented agent-based model for information retrieval

International audienceInformation Retrieval in the World Wide Web (Web IR) is essential for a number of activities and it is an active domain of research and development. The main challenges concern the relevance of the results provided to users' queries and the performance regarding respond-time. On the other hand, agent-based market systems prove to be efficient for implementing e-commerce or B2B applications on the internet, thanks to inherent properties such as prominency of interactions, scalability, flexibility, interoperability, etc. Although the use of agents in other application domains is not yet widespread, the integration of mobile agents into market mechanisms bring clear and efficient solutions to Quality of Service issues encountered in most distributed applications and notably in Web IR systems. Mobility allows defining the seller – buyer model of interaction, where agents act on behalf of final users or devices providing re-sources, while the generic Market Place architecture provides an organizational setting for the matching of demands and offers. The paper shows how this framework applies to Web IR and provides experimental validation results from a Jade implementation