A Component Framework for Java-based Real-time Embedded Systems

Rank (CORE): A.International audienceThe Real-Time Specification for Java (RTSJ) is becoming a popular choice in the world of real-time and embedded programming. However, RTSJ introduces many non-intuitive rules and restrictions which prevent its wide adoption. Moreover, current state-of-the-art frameworks usually fail to alleviate the development process into higher layers of the software development life-cycle. In this paper we extend our philosophy that RTSJ concepts need to be considered at early stages of software development, postulated in our prior work, in a framework that provides continuum between the design and implementation process. A component model designed specially for RTSJ serves here as a cornerstone. As the first contribution of this work, we propose a development process where RTSJ concepts are manipulated independently from functional aspects. Second, we mitigate complexities of RTSJ-development by automatically generating execution infrastructure where real-time concerns are transparently managed. We thus allow developers to create systems for variously constrained real-time and embedded environments. Performed benchmarks show that the overhead of the framework is minimal in comparison to manually written object-oriented approach, while providing more extensive functionality. Finally, the framework is designed with the stress on dynamic adaptability of target systems, a property we envisage as a fundamental in an upcoming era of massively developed real-time systems

Adapting Component-based Systems at Runtime via Policies with Temporal Patterns

International audienceDynamic reconfiguration allows adding or removing components of component-based systems without incurring any system downtime. To satisfy specific requirements, adaptation policies provide the means to dynamically reconfigure the systems in relation to (events in) their environment. This paper extends event-based adaptation policies by integrating temporal requirements into them. The challenge is to reconfigure component-based systems at runtime while considering both their functional and non-functional requirements. We illustrate our theoretical contributions with an example of an autonomous vehicle location system. An implementation using the Fractal component model constitutes a practical contribution. It enables dynamic reconfigurations guided by either enforcement or reflection adaptation policies

Decentralised Evaluation of Temporal Patterns over Component-based Systems at Runtime

Long version of the paper accepted for FACS 2014 - The 11th International Symposium on Formal Aspects of Component SoftwareInternational audienceSelf-adaptation allows systems to modify their structure and/or their behaviour depending on the environment and the system itself. Since reconfigurations must not happen at any but in suitable circumstances, guiding and controlling dynamic reconfigurations at runtime is an important issue. This paper contributes to two essential topics of the self-adaptation---a runtime temporal properties evaluation, and a decentralization of control loopsSelf-adaptation allows systems to modify their structure and/or their behaviour depending on the environment and the system itself. Since reconfigurations must not happen at any but in suitable circumstances, guiding and controlling dynamic reconfigurations at runtime is an important issue. This paper contributes to two essential topics of the self-adaptation - a runtime temporal properties evaluation, and a decentralization of control loops. It extends the work on the adaptation of component-based systems at runtime via policies with temporal patterns by providing a) a specific progressive semantics of temporal patterns and b) a decentralised method which is suitable to deal with temporal patterns of component-based systems at runtime

EVALUATION OF VISION-BASED LOCALIZATION AND MAPPING TECHNIQUES IN A SUBSEA METROLOGY SCENARIO

Metrology is fundamental in all the applications that require to qualify, verify and validate measured data according to standards or, in other words, to assess their compliance with predefined tolerances. At sea, metrology is commonly associated with the process of measuring underwater structures, mainly pipeline elements widely used in offshore industry. Subsea operations are very expensive; optimizing time and money resources are the core factors driving innovation in the subsea metrology industry. In this study, the authors investigate the use of state-of-art vision-based algorithms, i.e. ORB-SLAM2 and Visual Odometry, as a navigation tool to assist and control a Remotely Operated Vehicle (ROV) while performing subsea metrology operations. In particular, the manuscript will focus on methods for assessing the accuracy of both trajectory and tie points provided by the tested approaches and evaluating whether the preliminary real time reconstruction meets the tolerances defined in typical subsea metrology scenarios

A review of energy measurement approaches

International audienceReducing the energy footprint of digital devices and software is a task challenging the research in Green IT. Researches have proposed approaches for energy management, ranging from reducing usage of software and hardware, compilators optimization, to server consolidation and software migration. However, optimizing the energy consumption requires knowledge of that said consumption. In particular, measuring the energy consumption of hardware and software is an important requirement for efficient energy strategies. In this review, we outline the different categories of approaches in energy measurements, and provide insights into example of each category. We draw recommendations from our review on requirements on how to efficiently measure energy consumption of devices and software

Dal rilievo fotogrammetrico all’analisi dei dati. Il Progetto Shawbak

In this paper we present an interdisciplinary project which is a work in progress towards a 3D Geographical Information System with a specific focus application on the Castle of Shawbak. The Shawbak archaeological project is a specific and integrated project between medieval archaeological research and computer vision done thanks a long-term cooperation between University of Florence and LSIS/CNRS Marseille. Focusing mainly on stratigraphical analysis of upstanding structures we conducted a survey using photogrammetry, both in a tra¬ditional way and using the most advanced techniques to obtain a dense map, and then a tool for statistical analysis. The photogrammetric survey is driven directly by archaeological data which is formalized by ontologies as a link between all the archaeological concepts which are surveyed. The 3D GIS is the last step of this chain and aims at the automatic production of 3D models through archaeological database queries: these 3D models are, in fact, a graphic image of the database and at the same time the interface through which the user is able to modify it and produce different kinds of analysis

Caractérisation expérimentale de la dynamique des roues aubagées de turbomachines par mesures optiques

La conception dynamique des roues aubagées consiste à éviter que les modes de la structure ne soient excités par des harmoniques du régime moteur (coïncidences prédites à partir de l'analyse d'un diagramme de Campbell). En pratique, il est impossible d'éviter toute coïncidence sur l'ensemble de la plage de fonctionnement. Un essai moteur est effectué à la fin du cycle de conception pour déterminer les niveaux vibratoires. A partir de cet essai et du modèle EF validé, le concepteur vérifie ses marges fréquentielles et sait déterminer si la roue aubagée est soumise ou non au risque de fatigue vibratoire (HCF). Cette analyse nécessite plusieurs calculs EF dont les modèles ont été recalés par rapport à des essais partiels de distribution de contrainte (mesurée à l'aide de jauges de déformation). Une des limitations de ce type de mesure réside dans le caractère intrusif de l'instrumentation qui perturbe le comportement dynamique des aubes, notamment pour les modes de rang élevé. L'application de mesures optiques non intrusives sur des aubes est présentée ici, et met en évidence la précision qu'il est possible d'obtenir sur la mesure des déformées modales. De plus, ce papier illustre l'intérêt de borner la précision des mesures obtenues par exemple dans la caractérisation des dispersions en fréquence aube à aube, dispersions qui se traduisent par une amplification de la réponse aéroélastique de la structure