48 research outputs found

    Reconfiguration of Distributed Information Fusion System ? A case study

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    Information Fusion Systems are now widely used in different fusion contexts, like scientific processing, sensor networks, video and image processing. One of the current trends in this area is to cope with distributed systems. In this context, we have defined and implemented a Dynamic Distributed Information Fusion System runtime model. It allows us to cope with dynamic execution supports while trying to maintain the functionalities of a given Dynamic Distributed Information Fusion System. The paper presents our system, the reconfiguration problems we are faced with and our solutions.Comment: 6 pages - Preprint versio

    Structured Performance Analysis for Component Based Systems

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    International audienceThe Component Based System (CBS) paradigm is now largely used to design software systems. In addition, performance and behavioural analysis remains a required step for the design and the construction of efficient systems. This is especially the case of CBS, which involve interconnected components running concurrent processes. % This paper proposes a compositional method for modeling and structured performance analysis of CBS. Modeling is based on Stochastic Well-formed Nets (SWN), a high level model of Stochastic Petri nets, widely used for dependability analysis of concurrent systems. Starting from the definition of the system given in a suitable Architecture Description Language, and from the definition of the elementary components, we build an SWN of the global system together with a set of SWNs modeling the components of the CBS and their connections. From these models, we derive performances of the system thanks to a structured analysis induced by the structure of the CBS. We describe the application of our method through an example designed in the framework of the CORBA Component Model

    Modélisation et caractérisation expérimentale d'un échangeur à plaque d'une VMC

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    International audienceABSTRACT. In this paper, we model a heat exchanger of a mechanical ventilation system. The model uses the ε-NTU approach and takes into consideration the phenomenon of condensation on the cooled air side. The model is written with Modelica language using the " Standard " and the " Building " libraries. The results of the simulation of the dynamic model are discussed, and compared with on-site experimental data from the prototype.RÉSUMÉ. Dans cet article, nous présentons la description de l'échangeur d'un système de ventilation mécanique double flux. Le modèle est décrit selon la méthode ε-NUT avec prise en compte du phénomène de condensation du côté de l'air refroidi. La modélisation est effectuée sous Modelica à l'aide des bibliothèques « Standard » et « Building ». Les résultats de la simulation du modèle dynamique sont comparés aux mesures expérimentales effectuées sur le prototype

    Integrating OPC Data into GSN Infrastructures

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    This paper presents the design and the implementation of an interface software component between OLE for Process Control (OPC) formatted data and the Global Sensor Network (GSN) framework for management of data from sensors. This interface, named wrapper in the GSN context, communicates in Data Access mode with an OPC server and converts the received data to the internal GSN format, according to several temporal modes. This work is realized in the context of a Ph.D. Thesis about the control of distributed information fusion systems. The developed component allows the injection of OPC data, like measurements or industrial processes states information, into a distributed information fusion system deployed in a GSN framework. The component behaves as a client of the OPC server. Developed in Java and based on the Opensaca Utgard, it can be deployed on any computation node supporting a Java virtual machine. The experiments show the component conformity according to the Data Access 2.05a specification of the OPC standard and to the temporal modes

    Introduction de fonctionnalités d'auto-optimisation dans une architecture de selfbenchmarking

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    Le Benchmarking des systèmes client-serveur implique des infrastructures techniques réparties complexes, dont la gestion nécessite une approche autonomique. Cette gestion s'appuie sur une suite d'étapes, observation, analyse et rétroaction, qui correspond au principe d'une boucle de contrôle autonome. Des travaux antérieurs dans le domaine du test de performances ont montré comment introduire des fonctionnalités de test autonome par le biais d'une injection de charge auto-régulée. L'objectif de cette thèse est de suivre cette démarche de calcul autonome (autonomic computing) en y introduisant des fonctionnalités d'optimisation autonome. On peut ainsi obtenir automatiquement des résultats de benchmarks fiables et comparables, mettant en oeuvre l'ensemble des étapes de self-benchmarking. Notre contribution est double. D'une part, nous proposons un algorithme original pour l'optimisation dans un contexte de test de performance, qui vise à diminuer le nombre de solutions potentielles à tester, moyennant une hypothèse sur la forme de la fonction qui lie la valeur des paramètres à la performance mesurée. Cet algorithme est indépendant du système à optimiser. Il manipule des paramètres entiers, dont les valeurs sont comprises dans un intervalle donné, avec une granularité de valeur donnée. D'autre part, nous montrons une approche architecturale à composants et une organisation du benchmark automatique en plusieurs boucles de contrôle autonomes (détection de saturation, injection de charge, calcul d'optimisation), coordonnées de manière faiblement couplée via un mode de communication asynchrone de type publication-souscription. Complétant un canevas logiciel à composants pour l'injection de charge auto-régulée, nous y ajoutons des composants pour reparamétrer et redémarrer automatiquement le système à optimiser.Deux séries d'expérimentations ont été menées pour valider notre dispositif d'auto-optimisation. La première série concerne une application web de type achat en ligne, déployée sur un serveur d'application JavaEE. La seconde série concerne une application à trois tiers effectifs (WEB, métier (EJB JOnAS) et base de données) clusterSample. Les trois tiers sont sur des machines physiques distinctes.Benchmarking client-server systems involves complex, distributed technical infrastructures, whose management deserves an autonomic approach. It also relies on observation, analysis and feedback steps that closely matches the autonomic control loop principle. While previous works in performance testing have shown how to introduce autonomic load testing features through self-regulated load injection, the goal of this thesis is to follow this approach of autonomic computing to introduce self-optimization features in this architecture to obtain reliable and comparable benchmark results, and to achieve the fully principle of Self-benchmarking.Our contribution is twofold. From the algorithmic point of view, we propose an original optimization algorithm in the context of performance testing. This algorithm is divided into two parts. The first one concerns the overall level, i.e. the control of the performance index evolution, based on global parameters setting of the system. The second part concerns the search for the optimum when only one parameter is modified. From the software architecture point of view, we complete the Fractal component-based architecture, containing several autonomic control loops (saturation, injection, optimization computing) and we implement the coordination principle between these loops by asynchronous messages according to the publish-subscribe communication paradigm. To apply a given parameters setting on the system under test, we introduced new components Configurators to support the setting of parameters before starting the test process. It may also be necessary to restart all or part of the system to optimize to ensure that the new setting is effectively taken into account. We introduced components Starters to cover this need in a specific way for each system.To validate our self-optimization framework, two types of campaigns have been conducted onto the servers of Orange Labs in Meylan and the servers of the LISTIC Laboratory of the University of Savoie in Polytech Annecy-Chambéry (Annecy le Vieux). The first one is a WEB online shopping application deployed on a Java EE application server JonAS. The second one is a three-tiers application (WEB, business (EJB JOnAS) and data base) clusterSample. The three tiers are in three separate machines.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

    Video conference smart room: an information fusion system based on distributed sensors

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    International audienceThe needs for cross domain technologies called mecatronics have increased in the recent years and examples of mechanical tools directed by computers are now widely available. This paper gives an example of information fusion in the context of a video conference room and exposes two axes of the research. First it shows how to fuse information provided by several sources to locate a speaker. To do this, the system fuses data produced by video cameras and their associated image processing algorithm, with information resulting from signal processing algorithms applied on several micro-phones. Second, this article describes the distributed information fusion system (DIFS) used and the algorithm which decides where the speaker is located in order to allow focus on him. The whole application is managed by a new control system specifically developed for DIFSs. Some key points of the theoretical model on which the control is based are also given

    Quantum-Classical Computation of Schwinger Model Dynamics using Quantum Computers

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    We present a quantum-classical algorithm to study the dynamics of the two-spatial-site Schwinger model on IBM's quantum computers. Using rotational symmetries, total charge, and parity, the number of qubits needed to perform computation is reduced by a factor of 5\sim 5, removing exponentially-large unphysical sectors from the Hilbert space. Our work opens an avenue for exploration of other lattice quantum field theories, such as quantum chromodynamics, where classical computation is used to find symmetry sectors in which the quantum computer evaluates the dynamics of quantum fluctuations.Comment: 5 pages, 4 figures, 23 pages supplemental, 8 figures supplementa

    Introduction to MODELICA

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    Verification of probabilistic systems - Methods and tools

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    Historically, functional verification and performance evaluation have been two distinct stages in the development of applications. Each one had its own models and methods. For 15 years, numerous works covered both areas. These works are now referred to as probabilistic verification or, more accurately, by verification of probabilistic systems. This direction of research is prompted by the new needs of the modelers. They wish, for instance, to compute the probability that a property expressed as some logical formula is satisfied. They also wish to analyze a system including both non-deterministic and probabilistic features. The goal of this chapter is to introduce three important topics related to this research: - the definition of high level stochastic models; - the verification of Markov chains (MC); -the verification of Markov decision processes (MDP). We will always follow the same organization for these topics: - the detailed presentation of one approach, - an overview of the other approaches, - the description of an analysis tool related to this topic
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