Quantification du taux d'invalidité d'applications temps réel à contraintes strictes

International audienceThis work is about an operational conception toolkit for real time applications. Temporal validation is usually based on tools with binary validation results. In this paper, we show how to build some quality indicators able to quantify invalidity numerically. First, we present an automata-based model and then its geometrical adaptation, which permits to compute a measure of invalidit

Validation temporelle de systèmes de tâches temps-réel strictes à durée variables à l'aide de langages rationnels

16 pagesInternational audiencewe show that real-time systems composed of both periodic and sporadic interdependents tasks wich CPU time is not fixed can be validated from a methodology based on rational languages. This property leads to the cyclicity of the scheduling sequences for such systems

Term Validation of distributed hard real time applications

International audienceWe show that, when the modeled physical process is closed, finite automata and product operators are sufficient to valid distributed systems on an operational way

Discrete-Euclidean operations

International audienceIn this paper we study the relationship between the Euclidean and the discrete space. We study discrete operations based on Euclidean functions: the discrete smooth scaling and the discrete-continuous rotation. Conversely, we study Euclidean oper- ations based on discrete functions: the discrete based simplification, the Euclidean- discrete union and the Euclidean-discrete co-refinement. These operations operate partly in the discrete and partly in the continuous space. Especially for the discrete smooth scaling operation, we provide error bounds when different such operations are chained

Two discrete-continuous operations based on the scaling transform

International audienceIn this paper we study the relationship between the Euclidean and the discrete world thru two operations based on the Euclidean scaling function: the discrete smooth scaling and the discrete based geometrical simplification

Validation Temporelle d'Applications Temps Réel Distribuées à Contraintes Strictes

National audienceThis paper deals with temporal validation of distributed hard real time systems. We consider here the target machine physical properties. Indeed, several temporal characteristics of some tasks depend on hardware properties, and then influence the model. We suppose that there is no task migration, and we did not study the tasks allocation problem. We valid this method to the protocol CA

Quantification du taux d'invalidité d'applications temps réel : une approche géométrique

International audienceCe travail s'intègre dans un projet de conception d'outils d'aide à la spécification d'applications temps-réel à contraintes strictes : il s'agir, lorsqu'une application est invalide, d'identifier les causes de l'invalidité. Nous nous basons sur un modèle géométrique pour les applications temps-réel. Une mesure est définie à partir de ce modèle sur la base d'une distance géométrique. Les systèmes que nous traitons utilisent des ressources critiques et fonctionnent sur des architectures multiprocesseurs. Les tâches sont périodiques, non réentrantes, à départ différés

Local non-planarity of three dimensional surfaces for an invertible reconstruction: k-cuspal cells

International audienceThis paper addresses the problem of the maximal recognition of hyperplanes for an invertible reconstruction of 3D discrete objects. k- cuspal cells are introduced as a three dimensional extension of discrete cusps defined by R.Breton. With k-cuspal cells local non planarity on discrete surfaces can be identified in a very straightforward way

Validation of distributed periodic real-time systems using CAN protocol with finite automata

International audience‘In a previous work, we have defined a temporal model based on regular languages to validate periodic real-time systems: the feasability decisional process is expressed by means of algebraic operations on languages, such as intersection, Hadamard product, and language center computing. Here, we describe how this model can be used to validate periodic distributed real-time systems. We base this description on the example of the CAN network protocol

Using Discrete Geometry to model PFair scheduling algorithm for Real-Time systems applications

In this paper, we focus on the use of discrete geometry for the sake of real-time modeling and analysis. We consider multiprocessor context, and we determine the geometrical characterization of PFair scheduling algorithms, which are known to be very performant strategies. A feasability test can then be deduced from the geometrical properties