ModHel'X, un outil expérimental pour la modélisation multi-paradigmes

National audienceLa modélisation multi-paradigmes vise à permettre la modélisation d’un système en utilisant pour chacune de ses sous-parties le formalisme (ou paradigme) de modélisation le plus adapté. Nous nous intéressons plus spécifiquement à la modélisation du comportement de systèmes : dans ce cadre, il est nécessaire de pouvoir combiner la sémantique des différents formalismes utilisés dans un modèle de sorte à déterminer le comportement global du système modélisé. Nous avons conç̧u un outil appelé ModHel’X qui permet a) de décrire les formalismes de modélisation utilisés grâce au concept de modèle de calcul, b) de décrire l’adaptation sémantique à la frontière entre deux formalismes, c) de construire des modèles faisant appel à plusieurs de ces formalismes et d) de simuler le comportement de tels modèles

A formal abstract framework for modelling and testing complex software systems

International audienceThe contribution of this paper is twofold: first, it defines a unified framework for modeling abstract components, as well as a formalization of integration rules to combine their behaviour. This is based on a coalgebraic definition of components, which is a categorical representation allowing the unification of a large family of formalisms for specifying state-based systems. Second, it studies compositional conformance testing i.e. checking whether an implementation made of correct interacting components combined with integration operators conforms to its specification

An Approach of Domain Polymorph Component Design

International audienceHeterogeneous modelling and design tools allow the design of software systems using several computation models. The designed system is built by assembling components that obey a computation model. The internal behavior of a component is specified either in some programming language or by assembling sub-components that obey a possibly different computation model. When the same behavior is used in several computation models, it must be implemented in as many components as there are models, or, if the design platform supports it, it may be implemented as a generic component. Model-specific components require the recoding of the same core behavior several times, and generic components may not take model- specific features into account. In this paper, we introduce the notion of domain-polymorph component. Such a component is able to adapt a core behavior to the semantics of several computation models. The core behavior is implemented only once and is automatically adapted to the semantics of different computation models. Domain-polymorph components can be chosen by a system designer and integrated in a computation model: they will benefit from an appropriate execution environment and their semantics will be adapted to the host model. The designer will have the choice for several parameters of the adaptation. Contrary to generic components, such components adapt their behavior to the host model instead of letting the host model interpret their generic behavior. We also present an implementation of the concept of domain-polymorph component in the Ptolemy~II framework

Flat Heterogeneous Modeling

International audienceMost heterogeneous modeling environments allow only one model of computation at each hierarchical level of a model. The consequences are that (1) the transformations that occur at the boundary of two models of computation depend on the modeling tool and (2) the hierarchical structure of the model is perturbed by layers introduced to allow changes of model of computation. We introduce "heterogeneous interface components" to allow flat heterogeneous modeling. Such components have inputs and outputs that obey different models of computation. We present an execution model that allows the use of these components with any model of computation

Issues of Hierarchical Heterogeneous Modeling in Component Reusability

International audienceHeterogeneous systems are systems that obey different functioning laws. For instance, during the design of embedded systems, it is generally necessary to study both the controller and the environment that it controls, these two subsystems being clearly different in nature. Moreover, data processing applications are also increasingly heterogeneous, mixing different technical domains such as telecommunications, man-machine interface, analog and digital electronic, signal processing algorithms. To combine these different technology domains, modeling languages and platforms generally use a hierarchical approach. This paper highlights how the hierarchy of the model and the changes of model of computation are coupled and why this coupling forbids the use of components that have inputs or outputs that obey different models of computation. In addition, this paper shows that what happens when data crosses the boundary between two domains depends on the modeling environment and it gives some means of managing component in the same level of the hierarchy

Heterogeneous Model Composition in ModHel'X: the Power Window Case Study

This paper describes an heterogeneous model of a power window which is available on the ReMoDD repository. This model uses timed finite state machines for modeling the controller of the power window, synchronous data flows for modeling the mechanical part of the window, and discrete events for modeling the communications between the components on the car's bus. An important aspect of this model is the specification of the semantic adaptation between the heterogeneous parts of the model. This semantic adaptation is made for data, control, and time. The semantic adaptation of control and time relies on the TESL library which is an implementation of the model of time used in the ModHel'X platform. The model can be run using a simulation scenario with a graphical display of the outputs. The semantic adaptation can be disabled in order to show how it affects the behavior of the model. The demo can also be run with a graphical interface and a user in the loop

An approach to design smart grids and their IT system by cosimulation

International audienceSmart grids are the oncoming generation of power grids, which rely on information and communication technologies to tackle decentralized and intermittent energy sources such as wind farms and photovoltaic plants. They integrate electronics, software information processing and telecommunications technical domains. Therefore the design of smart grids is complex because of the various technical domains and modeling tools at stake. In this article, we present an approach to their design, which relies on model driven engineering, executable models and FMI based cosimulation. This approach is illustrated on the use case of an insular power grid and allows to study the impact of power production decision

La délimitation maritime en mer de Beaufort, entre immobilisme et indifférence ?

Plusieurs revendications sur des espaces maritimes en Arctique se traduisent par des litiges entre États riverains, même si nombre de disputes ont été résolues à travers des négociations. Parmi ces litiges, on retrouve le différend entre États-Unis et Canada portant sur les limites de leur Zone Économique Exclusive en mer de Beaufort. Il s'agit d'un litige relativement ancien (1977) et qui, malgré les relations cordiales entre Ottawa et Washington, ne semble pas connaitre de solution. Cet article se propose d'analyser la situation en mer de Beaufort, afin d'évoquer des clefs de réflexion sur le pourquoi de la pérennisation de ce différend. Il s'agit de proposer une lecture synthétique d'éléments juridiques et de documents gouvernementaux permettant de rendre compte du faible empressement des gouvernements à résoudre ce litige de basse intensité.Several claims on maritime spaces in the Arctic have resulted in disputes between riparian states, even though many of these disputes have been solved through negotiations. Among these disputes, we find the disagreement between the United States and Canada concerning the limits of their Exclusive Economic Zone in the Beaufort Sea. This is a relatively old dispute (1977) which, despite the cordial relations between Ottawa and Washington, does not seem to find a solution. This article aims at analyzing the situation in the Beaufort Sea, in order to present the reasons for the continuation of this dispute. Based on legal elements and government documents, the objective is to offer a synthetic reading of the factors that explain the weak commitment of the American and Canadian governments to solve this low-priority dispute