Mimosa: Using ontologies for modeling and simulation

Modeling is the shared activity for both modeling and simulation, and knowledge representation. At the same time, the objectives of these two domains are not the same and both seem necessary when dealing with modeling highly structured and complex systems. To face the complexity of the systems we are trying to model and to simulate nowadays, the challenge addressed in this paper is to mix both approaches in a common framework. We first describe separately the recent advances made in the modeling and simulation community as well as in the knowledge representation community. We show that, despite the same goal to describe a reality, or at least a part of it, it results in very different, although related concepts. This difference is due to the focus taken by these communities. The first community is centered on dynamics, and the second one on static descriptions. From the analysis of the differences and similarities, we propose an architecture which is being tested in a modeling and simulation platform: Mimosa. The outcome is a formal way to pave the path from conceptual to running models which is sketched in this paper. The achievements and the perspectives are discussed in the conclusion. (Résumé d'auteur

Mimosa: using ontologies for modeling and simulation

Modeling is the shared activity for both modeling and simulation, and knowledge representation. At the same time, the objectives of these two domains are not the same and both seem necessary when dealing with modeling highly structured and complex systems. To face the complexity of the systems we are trying to model and to simulate nowadays, the challenge addressed in this paper is to mix both approaches in a common framework. We first describe separately the recent advances made in the modeling and simulation community as well as in the knowledge representation community. We show that, despite the same goal to describe a reality, or at least a part of it, it results in very different, although related concepts. This difference is due to the focus taken by these communities. The first community is centered on dynamics, and the second one on static descriptions. From the analysis of the differences and similarities, we propose an architecture which is being tested in a modeling and simulation platform: Mimosa. The outcome is a formal way to pave the path from conceptual to running models which is sketched in this paper. The achievements and the perspectives are discussed in the conclusion. (Résumé d'auteur

The mimosa generic modelling and simulation platform : The case of multi-agent systems

The aim of this paper is to introduce Mimosa: a generic platform for modelling and simulation and to show its applicability to the specification of multi-agent simulations based on the AGR (Agent-Group-Role) model. The Mimosa platform allows to describe the appropriate formalisms for the targeted models and then the models themselves. Moreover, it is able to articulate several models for modelling complex systems. This capability is illustrated by showing how the notions of environment, agents, groups and roles are specified, instantiated into concrete models and then run through the specification of the notion of scheduler. Finally, an running example is given. (Résumé d'auteur

Integrated modeling : from models to theories and back

"A is a model of B for X if manipulating A allows to answer the questions of X on B"(Minsky 65). It follows that the formal structure A, the system B, and A being a model B depends on X and his questions. Integrated modeling is thought as the process of putting together several models (say A1 to An) or to build a new model A'which subsumes the models which would have been designed separately. We argue the main limitation lies in the lack of explicitation of how Ai or A' relates to Bi or B' for the Xs performing integrated modeling.To make the relationship between A and B formally explicit, we need a formal proxy of B. The usual proxy is the set of observations we have about B. We suggest that another proxy of B is the theory in the philosophical sense of a conceptual explanation of how the system B behaves associated with its ontology. We argue that the theories in the philosophical sense must be made explicit because integrated modeling is about articulating theories and not only about integrating models. From our experience in multidisciplinary contexts, we are using ontologies, and combining and articulating these becomes the heart of the integrated modeling process. The formalism (differential equations, multi--?agents systems, etc.) is chosen after and associated with the ontologies. Both the articulation among theories, and the process of abstraction between the theories and the chosen formal structures is in the center of the integrated modeling process. (résumé d'auteur

A generic model to assess sustainability impact of resource management plans in multiple regulatory contexts

Management of the renewable natural resources in Madagascar is gradually being transferred to the local communities. However, these local communities are struggling to assess the consequences of the management plans they must develop and implement on ecologically, economically and socially sustainable grounds. From this Malagasy case, we propose, from a law anthropology perspective, a generic model, called MIRANA, that allows taking into account law pluralism in the analysis of the impact on sustainability of agents' behaviors submitted to concurrent normative orders within multiple layered territories. From a regulatory perspective, we will describe the representations of institutions and norms, and how they are enforced by control/sanction strategies. From an individual perspective, we will describe how an agent deals with a multiplicity of normative and incentive structures. Additionally, individual behaviors are specified as a combination of subsistence economy, market economy and contractual relations. (Résumé d'auteur

Companion modelling within the project "a Stakeholder driven process to develop a catchment management plan for the Kat River Valley" : WRC Project n° K5/1496

The main objective of the project "A Stakeholder driven process to develop a Catchment Management Plan (CMP) for the Kat River Valley" (the Kat Project hereafter) was to assist the Kat River Water Users Association (KRWUA) in the development of a CMP in which water is allocated and provided to the various users for the present and future requirements of these users and the Reserve (O'Keefe et al., 2004). An important aspect in the development of a CMP is represented by the negotiation and common decision-making process that must take place among the different water users nominated in the KRWUA board. Originally it was planned to simply calibrate the existing model, AWARE, to the Kat River Valley situation, and to use the resulting scenarios as the basis for discussion and negotiation within the KRWUA. However, in the beginning of the Kat Project and after one trip to Grahamstown and the Kat River Valley by a Cirad researcher, it was agreed by the project coordinators that instead of adapting the existing AWARE model to the Kat reality, a radically new model should be constructed, developed within the Companion Modelling (ComMod) process. is specific to each situation. The endless following cycle 'field work- modelling - simulation - field work again, etc.' corresponds to this concept. This leads to the acceptance of a diversity of models and methods, each contributing to a new kind of relationship between the simulation, the research itinerary, and the decision-making process" (ComMod Group, 2003, 4.1). Another important characteristic of ComMod is the joint use of Role-Playing Games (RPG) and models, particularly Multi-Agent Systems (MAS). "The association of an RPG with a MAS ... seems to provide a good way to explain the content of a model in order to validate it and to communicate upon its basis" (Barreteau et al., 2001, 5.9). Following the ComMod methodology, a MAS (KatAWARE) and a related RPG were developed to contribute to the process of building the capacity of stakeholders to actively participate in designing a platform and context for their negotiation process and to select decision-making criteria for their catchment (Farolfi and Rowntree, 2005). After having briefly presented the composition of the team involved in this action research process (2), the text that follows summarizes the ComMod process in the Kat (3) referring to the reports that explain each step and used tools in details. A discussion on the successes and shortcomings of the ComMod process in the Kat is then proposed (4) and final remarks and suggestions for the possible future adoption of this research methodology in the South African context are provided (5). (Résumé d'auteur

A generic model to assess sustainability of resource management plns within concurrent regulatory contexts

Management of the renewable natural resources in Madagascar is gradually being transferred to the local communities. However, these local communities are struggling to assess the consequences of the management plans they must develop and implement on sustainability, within concurrent regulatory contexts. From this Malagasy case, we derived, from a law anthropology perspective, a generic model called MIRANA. From a social perspective, MIRANA formalizes institutions as sets of constitutive and regulatory norms, defining multiple layered territories, and multiple perspectives on the agents and resources. From an individual perspective, MIRANA specifies agents' behaviors as a combination of subsistence, production, and contractual relations, accounting for a multiplicity of normative and incentive structures to compromise and to implement. MIRANA allows to analyze the impact on sustainability of agents' behaviors submitted to concurrent normative orders, in a context of law pluralism. (Résumé d'auteur

Modelling the Minsky triad: A framework to perform reflexive MandS studies

In this paper, we propose a general framework to evaluate models of systems that are ill defined, incompletely known, and furthermore, which cannot be experimented in real conditions, such as the economical systems at the country scale, epidemics (for obvious ethical reasons) or any natural disasters, for instance where human lives are the main issue. Our framework relies on the generic Marvin Minsky's definition of a model and its specification in the frame of the Theory of Modelling and Simulation, initiated by B.P. Zeigler. Such a dynamic system implementation of the Marvin Minsky's model definition, we called the Minsky triad model, enables to address original questions. The Minsky triad model is a coupled model composed of the model of a real system, the model of this later model, and, in between, the model of the user of the later model. We argue that the Minsky triad model is very promising as a framework to design and to evaluate decision support systems for crisis management. (Résumé d'auteur