Polychronous mode automata

International audienceAmong related synchronous programming principles, the model of computation of the Polychrony workbench stands out by its capability to give high-level description of systems where each component owns a local activation clock (such as, typically,distributed real-time systems or systems on a chip). In order to bring the modeling capability of Polychrony to the context of a model-driven engineering toolset for embedded system design, we define a diagramic notation composed of mode automata and data-flow equations on top of the multi-clocked synchronous model of computation supported by the Polychrony workbench. We demonstrate the agility of this paradigm by considering the example of an integrated modular avionics application. Our presentation features the formalization and use of model transformation techniques of the GME environment to embed the extension of Polychrony's meta-model with mode automata

Modeling multi-clocked data-flow programs using the Generic Modeling Environment

International audienceThis paper presents Signal-Meta, the metamodel designed for the synchronous data-flow language Signal. It relies on the Generic Modeling Environment (GME), a configurable object-oriented toolkit that supports the creation of domain-specific modeling and program synthesis environments. The graphical description constitutes the base to build multi-clock environments, and a good front-end for the Polychrony platform. To complete this frontend, we develop a tool that transforms the graphical Signal-Meta specifications to the Signal code. This modeling paradigm constitutes a first work for generalizing the use of formal methods proposed by Polychrony

Sécurité de la plate-forme d'exécution Java : limites et propositions d'améliorations

National audienceLe choix de Java est souvent guidé par la sécurité qu'il est censé apporter. La plate-forme d'exécution Java assure en effet des propriétés de sécurité permettant notamment de se prémunir contre l'exploitation de la mémoire. Toutefois, de nombreuses vulnérabilités publiques concernent Java, notamment sa bibliothèque standard. Qu'en est-il donc de l'apport de Java en termes de sécurité? Quelles sont ses faiblesses? Quelles améliorations sont envisageables? Cet article tente de répondre à ces questions. Il décrit tout d'abord les différents composants de la plate-forme d'exécution Java en détaillant les mécanismes de sécurité offerts et les propriétés garanties. Il analyse ensuite les différentes faiblesses de ces composants et propose enfin des pistes pour l'amélioration de la sécurité de la plate-forme

Acute Muscular Sarcocystosis: An International Investigation Among Ill Travelers Returning From Tioman Island, Malaysia, 2011-2012

A large outbreak of acute muscular sarcocystosis (AMS) among international tourists who visited Tioman Island, Malaysia, is described. Clinicians evaluating travelers returning ill from Malaysia with myalgia, with or without fever, should consider AMS in their differential diagnosi

Biomarkers of Nutrition for Development (BOND)—Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health. The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation

Construction et simulation graphiques de comportements : le modèle des Icobjs

Intuitively, a graphical simulation (virtual world, game,...) can be seen as a finite space in which several entities, each having its own behavior, evolve in parallel. So it seems natural to use concurrent languages to program those behaviors. However, it is seldom the case due to the complexity of programming and debugging them, because they introduce non-determinism and are inefficient. We proposed to use the Reactive Approach introduced by F. Boussinot to define clearly the behaviors of graphical entities. We enhanced a model of graphical reactive objects called Icobjs. This model enables non-specialists to graphically build complex behaviors using elementary behaviors and graphical constructors. We realized an API whose main class is Icobj. It defines a minimal structure which can be dynamically extended and which allows a generic graphical construction. A particular icobj called Workspace executes and displays all the icobjs it contains. Behaviors are executed by a reactive engine called Reflex which is dedicated to Icobjs. It reuses Junior?s formalism?s main primitives, while modifying some instructions? semantics and introducing new instructions. We formalized all instructions using rewriting rules in the SOS format. Moreover, we developed a framework for dynamic interaction with simulations. Finally, we present a few experiments with Icobjs in distributed, physical or multi-clock simulations.Intuitivement, une simulation graphique (monde virtuel, jeu,...) peut etre vue comme un espace borne dans lequel plusieurs entites, disposant chacune d'un comportement propre, evoluent en parallele. Il parait donc naturel d'utiliser des langages concurrents pour programmer ces comportements. Cependant, c'est rarement le cas pour des raisons de complexite de programmation et de deboguage, de non-determinisme et d'efficacite. Nous proposons d'utiliser l'Approche Reactive introduite par F. Boussinot qui permet de definir clairement les comportements d'entites graphiques. Nous avons enrichi les Icobjs qui est un modele d'objets reactifs graphiques. Il offre la possibilite a des non-specialistes de construire graphiquement des comportements complexes a partir de comportements simples et de constructeurs graphiques. Nous avons realise une implementation dont l'objet central est Icobj. Il definit une structure minimale dynamiquement extensible pour permettre une construction graphique generique. Un icobj particulier, le Workspace, execute et affiche les icobjs qu'il contient. Les comportements sont executes par un moteur reactif dedie aux Icobjs appele Reflex. Il reprend les principales primitives du formalisme Junior en modifiant la semantique de certaines instructions et en y ajoutant de nouvelles. Toutes les instructions sont formalisees par des regles de reecritures au format SOS. De plus, nous avons developpe un environnement qui permet d'interagir dynamiquement avec les simulations. Enfin, nous presentons quelques experimentations autour de l'utilisation des Icobjs dans le cadre de simulations distribuees, de simulations physiques ou de simulations multi-horloges

A Visual Reactive Framework for Dynamic Behavior Creation

This paper presents Icobjs, a simple, Java-based, visual framework for the programming of reactive applications. In the Icobjs ("Iconic Object") formalism, graphical objects represent basic and hierarchically composed reactive behaviors that can be easily combined to produce more complex ones. The reactive language, on which Icobjs is based, is called Junior. It provides parallelism and broadcast events communication

Compositional modeling and transformation of multi-clocked mode automata

This article presents the modeling and implementation of multi-clocked mode automata using the model-driven engineering tool GME(Generic Modeling Environment) and starting from a meta-model for the computer-aided embedded system design tool POLYCHRONY. The article presents the design of a meta-model in GME for the data-flow multi-clocked synchronous formalism Signal of POLYCHRONY, its extension to multi-clocked mode automata and the use of model transformation technologies of the GME environment to embed the latter extension in the former workbench. The complete model and transformation process is formalized and given a formal operational semantics