WorldCat Identities

Lapayre, Jean-Christophe

Overview
Works: 18 works in 27 publications in 2 languages and 29 library holdings
Roles: Thesis advisor, Opponent, Other, Author, Contributor, 956
Publication Timeline
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Most widely held works by Jean-Christophe Lapayre
Conception et developpement d'un environnement de programmation cooperative a memoire partagee by Jean-Christophe Lapayre( Book )

2 editions published in 1998 in French and held by 3 WorldCat member libraries worldwide

DANS LA LITTERATURE, NOUS TROUVONS DE NOMBREUSES APPLICATIONS DE TRAVAIL COOPERATIF : AGENDAS DISTRIBUES, EDITEURS DE TEXTE PARTAGES, EDITEURS GRAPHIQUES, VIDEO-CONFERENCE ET PLUS GENERALEMENT UNE GRANDE PARTIE DES APPLICATIONS MULTIMEDIA. EN ETUDIANT LES MECANISMES PROPRES A CES APPLICATIONS, IL NOUS EST APPARU INTERESSANT DE DEVELOPPER UNE PLATE-FORME SPECIFIQUE. LE CONCEPT DE PARTAGE EST TRES IMPORTANT DANS LA COOPERATION : PARTAGE DE TRAVAIL, PARTAGE DE CONTEXTE, PARTAGE DE DONNEES. NOUS PROPOSONS UN ENVIRONNEMENT A MEMOIRE PARTAGEE, QUI SE NOMME CALIF : COOPERATIVE APPLICATION FRAMEWORK. AFIN DE BIEN IDENTIFIER LES DIFFERENTS MECANISMES COMMUNS A TOUT SYSTEME COOPERATIF, NOUS AVONS DEFINI NOTRE PLATE-FORME SUR QUATRE NIVEAUX : _ LE NIVEAU COMMUNICATION OFFRE UN RESEAU DE CANAUX ENTRE LES NOEUDS. _ LE NIVEAU MEMOIRE VIRTUELLE PARTAGEE PROPOSE UN ESPACE VIRTUEL DE MEMOIRE QUI PERMET DE GERER DE MANIERE TRANSPARENTE LES VARIABLES PARTAGEES. UN MODULE PARTICULIER EST CHARGE DE GERER LA COHERENCE DE LA MEMOIRE. _ LE NIVEAU SERVICES DE CALIF, PROPOSE DEUX TYPES DE SERVICE : _ LE SERVICE GROUPES GERE L'UTILISATION DES GROUPES DE PROCESSEURS ET DES GROUPES DE PROCESSUS. _ LE SERVICE GESTION DE LA COOPERATION PROPOSE DIFFERENTES FONCTIONS USUELLES DANS LES APPLICATIONS COOPERATIVES : L'ENTREE EN COOPERATION (CREATION DYNAMIQUE DE LA MACHINE), LA CONNEXION D'UN DEMON, LA CONNEXION D'UN MEMBRE D'UNE APPLICATION, LA SORTIE DE COOPERATION, LA DIFFUSION CETTE DERNIERE FONCTION EST MAJEURE DANS UN ENVIRONNEMENT DISTRIBUE. DE NOMBREUSES FONCTIONS UTILISENT LA DIFFUSION : DIFFUSION D'INVALIDATION, DE SON, D'IMAGE _ LE NIVEAU APPLICATION DISTRIBUEE COOPERATIVE OFFRE UN GRAND NOMBRE DE LIBRAIRIES AIDANT AU DEVELOPPEMENT D'APPLICATIONS COOPERATIVES. IL PROPOSE PAR EXEMPLE LES LIBRAIRIES SUIVANTES : CALIFEDITING, CALIFAUDIO, CALIFVIDEO OU CALIFDRAW NOUS PROPOSONS UN NOUVEAU PROTOCOLE DE COHERENCE POUR LE NIVEAU MEMOIRE PARTAGEE DE CALIF OU LES OBJETS PARTAGES SONT REPLIQUES SUR CHAQUE SITE. NOUS PRESENTONS CET ALGORITHME QUI UTILISE LA TECHNIQUE DU JETON. CE DERNIER EST UNE STRUCTURE CONTENANT LES MISES A JOUR DES OBJETS PARTAGES. LE JETON CIRCULANT SUR UN ANNEAU VIRTUEL EST APPELE LE PELERIN. CE PROTOCOLE PERMET A LA FOIS UNE COHERENCE EFFICACE MAIS AUSSI UNE GARANTIE DE PERFORMANCES EN ACCORD AVEC LES APPLICATIONS COOPERATIVES. NOUS LE DECRIVONS, LE PROUVONS ET NOUS DEMONTRONS SES QUALITES
Evaluation, optimisation et validation de protocoles distribués de gestion de la concurrence pour les interactions coopératives by Julien Henriet( Book )

2 editions published in 2005 in French and held by 2 WorldCat member libraries worldwide

Le développement fulgurant de la télé-informatique a permis l'apparition de nombreux logiciels pour le travail de groupe d'où les vocables collecticiels, applications coopératives ou collaboratives. Mais le travail collaboratif sur Internet place des contraintes en terme de concurrence d'accès aux données partagées et de communication ; n utilisateurs accédant aux mêmes données doivent en avoir la même vision, une vision cohérente. La première partie de cette thèse est un état de l'art des protocoles de communication et de gestion de la cohérence des données, des outils de communication, ainsi qu'un tour d'horizon des applications et plates-formes dédiées plus particulièrement à la télé-médecine coopérative. La deuxième partie est l'étude et l'amélioration du protocole du Pèlerin. Ce protocole pessimiste est implémenté sur notre plate-forme coopérative nommée CAliF et une version optimiste est proposée, permettant aux utilisateurs de réaliser plus rapidement leurs modifications des objets partagés. Cette partie comporte aussi une étude théorique des performances de ce nouveau protocole par rapport aux performances du Pèlerin classique. La troisième partie présente, modélise et étudie le protocole de gestion des communications de CAliF : le Caméléon. Cette étude est faite au travers de Réseaux de Pétri. La quatrième partie est une étude pratique de ces protocoles à l'aide d'une implémentation basée sur l'intergiciel SOAP et leur adéquation avec les outils de la plate-forme du projet de télé-neurologie TéNeCi. Dans le cadre de ce projet, des neurologues des hôpitaux de Besançon et de Lausanne doivent pouvoir réaliser des diagnostics de manière coopérative en temps réel
Elaboration d'une nouvelle approche de tatouage réversible pour la vérification d'intégrité des images médicales by Imen Fourati Kallel( Book )

2 editions published in 2009 in French and held by 2 WorldCat member libraries worldwide

With the great spread of computer network and the rapid development of multimedia technologies, the medical images can be readily shared via computer networks used, processed, and transmitted. This development has caused problems relative to the authentication and integrity. Fragile watermark is the best method that has been proposed for the protection of images. It is in this context that this project is described. It consists to develop a new approach of reversible watermarking and validated within the European project DECOPREME(COllabotative PREcocious DEtection of Melanoma). The proposed reversible fragile watermarkirig approach is able to detect any tampering in a marked image during his transfer and locate the modified areas and it has the advantage of finding the original image from marked the image whose integrity is verified. This reversibility is needed in all areas of sensitive imagery, especially the medical sector
Medical Image Compression Approach Based on Image Resizing, Digital Watermarking and Lossless Compression by Hedi Amri( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Representation of thermal building simulation in virtual reality for sustainable building by Yudi Nugraha Bahar( Book )

2 editions published in 2014 in English and held by 2 WorldCat member libraries worldwide

The importance of energy efficiency as well as integration of advances in sustainable buildingdesign and VR technology have lead this research to focus on thermal simulation results visualized in avirtual environment (VE). The emphasis is on the representation of thermal building simulation (TBS)results and on the perception of thermal data simulated in a VE. The current application of the designprocess through energy efficiency in VR systems is limited mostly to building performance predictionsand design review, as the issue of the data formats and the workflow used for 3D modeling, thermalcalculation and VR visualization.Different applications and tools involved to represent TBS in VE are become the challenge ofthis work. Many 3D modeller, thermal simulation tools and VR tools are available and they are differ intheir function and platform. Issues of data format exchange, appropriate tools and equipments from thissituation require an interoperability solution that needs to be structured in a workflow method.Significances and barriers to integration design with CAD and TBS tools are also outlined in order totransfer the model to VR system. Therefore, the idea then is to use Building Information Model (BIM)extensively used in Architecture, Engineering and Construction (AEC) community. It then continued toevaluate the current trends for TBS representation in VE, to create data transfer method, and tointegrate them in the workflow. After a review in thermal simulation and an evaluation of related works,we specify the application, method and tools for our objectives.An application of a method of data transfer and presentation of data in VE are formulated andtested. This effort conduct using a specific data workflow which performed the data transfer through 3phases. This relies on the smooth exchange of data workflow between CAD tools, thermal calculationtools and VR tools. Presentation of data in VE is conducted through immersive visualization andintuitive interaction. An experiment scenario of a thermal simulation in VR system was created tointeractively visualize the results in the immersion room and tested by some respondents. The systeminclude with friendly interface for interaction. It presents a realistic 3D model of the project (Gunzoroom) in existing condition and renovated version, and their TBS results visualized in somevisualization metaphor. In the experiment, the method which bundled in an application brings togetherwithin a couple of virtual scenario and a software/hardware solution. The obtained results concentrateon visualization, interaction and its feedback. Some visualization metaphor are tested and evaluated topresent more informative TBS results where the user can interact and perceive the impact of theiraction.Evaluation of the application prototype showed various levels of user satisfaction, andimprovements in the accuracy and efficiency of data interpretation. The research has demonstrated it ispossible to improve the representation and interpretation of building performance data, particularly TBSresults using visualization techniques. Using specific method, the data flow that starts from the designprocess is completely and accurately channelled to the VR system. The method can be used with anykind of construction project and, being a flexible application, accepts new data when necessary,allowing for a comparison between the planned and the constructed
Fusion de segmentations complémentaires d'images médicales par Intelligence Artificielle et autres méthodes de gestion de conflits by Lisa Corbat( )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

Nephroblastoma is the most common kidney tumour in children and its diagnosis is based exclusively on imaging. This work, which is the subject of our research, is part of a larger project: the European project SAIAD (Automated Segmentation of Medical Images Using Distributed Artificial Intelligence). The aim of the project is to design a platform capable of performing different automatic segmentations from source images using Artificial Intelligence (AI) methods, and thus obtain a faithful three-dimensional reconstruction. In this sense, work carried out in a previous thesis of the research team led to the creation of a segmentation platform. It allows the segmentation of several structures individually, by methods such as Deep Learning, and more particularly Convolutional Neural Networks (CNNs), as well as Case Based Reasoning (CBR). However, it is then necessary to automatically fuse the segmentations of these different structures in order to obtain a complete relevant segmentation. When aggregating these structures, contradictory pixels may appear. These conflicts can be resolved by various methods based or not on AI and are the subject of our research. First, we propose a fusion approach not focused on AI using the combination of six different methods, based on different imaging and segmentation criteria. In parallel, two other fusion methods are proposed using, a CNN coupled to the CBR for one, and a CNN using a specific existing segmentation learning method for the other. These different approaches were tested on a set of 14 nephroblastoma patients and demonstrated their effectiveness in resolving conflicting pixels and their ability to improve the resulting segmentations
COLISEUM-3D : Une plate-forme innovante pour la segmentation d'images médicales par Raisonnement à Partir de Cas (RàPC) et méthodes d'apprentissage de type Deep Learning by Florent Marie( )

2 editions published in 2019 in French and held by 2 WorldCat member libraries worldwide

Nephroblastoma (or Wilms' tumor) affects the kidney and is the most common childhood abdominal cancer tumor. During therapy, it is recommended to preserve kidney function as well as possible by preserving the pathological kidney under certain conditions. The information from the imagery is important to validate them, but partly involves segmentation of the scan images. As this task is very time-consuming, it is common for this information not to be fully exploited. Artificial Intelligence (AI) represents a promising way to automate segmentations but generally requires a large amount of learning data. Among other things, Case-Based Reasoning (CBR) is a knowledge-based AI approach that integrates business knowledge and an adaptation of an existing solution to optimize the resolution of a new problem. Convolutional Neural Networks (CNNs) are a purely experiential approach. We propose a CBR system coupled with a region growing algorithm in order to segment kidneys deformed by nephroblastoma. In parallel, a training method for CNNs, called OV[exposant ]2ASSION, is also proposed for tumor segmentation. Both approaches aim to address a lack of learning data (few segmentations of nephroblastoma and pathological kidneys are available). The evaluations show good performance with the calculation of segmentations similar to those made by radiologists and surgeons
I²PHEN : une nouvelle plateforme de télésurveillance médicale basée sur l'Internet des Objets by Alexis Picard( )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

Medical telemonitoring is an area still in full development in France. It is a branch of telemedicine which aims at enabling a doctor in collecting and interpreting remotely the data necessary for the medical follow-up of a patient. It enables, among others, in improving remote medical monitoring of seniors with loss of autonomy or suffering from chronic diseases (heart diseases, diabetes and high blood pressure for example). Hence it encourages their stay at home and to warn as soon as possible of any hospitalizations.This CIFRE Thesis within Maincare company (major publisher of digital solutions for the world of health) allowed us to propose our novel platform I²PHEN (IoT Interoperable Platform for Health moNitoring low power) in which the monitoring of a patient's health parameters is done using connected objects (sphygmomanometer, thermometer, glucometer, ...) which communicates with the remote platform (distributed data monitoring). The central server can then trigger alerts which are defined beforehand with the medical teams. The technological choice of the networks used is a major concern. LPWAN networks (Low-Power Wide Area Network) offer a cost-effective alternative and are less expensive in terms of energy than cellular networks to transmit small amounts of data from sensors and energy efficient objects powered on batteries over important distances. This field being new, and still little dedicated to the medical field, it is necessary to develop new focus of research such as COMMA, a new adaptive algorithm to reduce energy consumption and interference in daily mobility. Hence, the first lock is the energy consumption, in relation to the quality of service (QoS), of these new networks in the critical area of telemedecine. The second lock, and probably the most difficult, is to propose interoperable solutions in which connected objects can interact, through these new networks, with the remote platform through a local gateway (based on Arduino). In the end, the platform that we propose in this PHD allows the telemonitoring of patients from end to end, is interoperable and energy efficient
Adaptabilité des flux multimédia appliquée au télé-diagnostic médical by Ronnie Muthada Pottayya( )

2 editions published in 2017 in French and held by 2 WorldCat member libraries worldwide

In the medical area, most of medical facilities (hospitals, clinics, ldots) use distributed applications in the context of telemedecine.As information security is mandatory, these applications must be able to cross the security protocols (secured gateways like proxies, firewalls, ldots). User Datagram Protocol (UDP), which is classically recommended for videoconferencing applications, does not cross firewalls or proxies unless explicitly configured fixed ports are declared. These fixed ports are considered as a security breach.In this thesis, we propose a novel platform called VAGABOND (Video Adaptation framework, crossing security GAteways, Based ON transcoDing) which works, in a very efficient and original way; on TCP (Transmission Control Protocol). VAGABOND is composed of Adaptation Proxies (APs), which have been designed to take into consideration medical experts videoconferencing preferences, device heterogeneities, and network dynamic bandwidth variations. VAGABOND is able to adapt itself at the user and network levels.The cumulative binomial probability law and the Bayesian inference on a binomial proportion are used to trigger user profile adaptations. In fact, we aim at being more tolerant to severe network bandwidth variations. With a finer precision and following these probability laws, user profile adaptation is only triggered when severe network congestions arise. However, as TCP is a reliable transport protocol, we needed to design and to employ new intelligent adaptation strategies together with data transmission in order to cope with latency issues and sockets timeout
Cryptographie sur les courbes elliptiques et tolérance aux pannes dans les réseaux de capteurs by Yanbo Shou( Book )

2 editions published in 2014 in French and held by 2 WorldCat member libraries worldwide

The emergence of embedded systems has enabled the development of wireless sensor networks indifferent domains. However, the security remains an open problem. The vulnerability of sensor nodesis mainly due to the lack of resources. In fact, the processing unit doesn't have enough power ormemory to handle complex security mechanisms.Cryptography is a widely used solution to secure networks. Compared with symmetric cryptography,the asymmetric cryptography requires more complicated computations, but it offers more sophisticated key distribution schemes and digital signature. In this thesis, we try to optimize the performance of ECC. An asymmetric cryptosystem which is known for its robustness and the use of shorter keys than RSA. We propose to use parallelismtechniques to accelerate the computation of scalar multiplications, which is recognized as the most computationally expensive operation on elliptic curves. The test results have shown that our solution provides a significant gain despite an increase in energy consumption.The 2nd part of our contribution is the application of fault tolerance in our parallelism architecture. We use redundant nodes for fault detection and computation recovery. Thus, by using ECC and fault tolerance, we propose an efficient and reliable security solution for embedded systems
Logo detection, recognition and spotting in context by matching local visual features by Viet Phuong Le( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

This thesis presents a logo spotting framework applied to spotting logo images on document images and focused on document categorization and document retrieval problems. We also present three key-point matching methods: simple key-point matching with nearest neighbor, matching by 2-nearest neighbor matching rule method and matching by two local descriptors at different matching stages. The last two matching methods are improvements of the first method. In addition, using a density-based clustering method to group the matches in our proposed spotting framework can help not only segment the candidate logo region but also reject the incorrect matches as outliers. Moreover, to maximize the performance and to locate logos, an algorithm with two stages is proposed for geometric verification based on homography with RANSAC. Since key-point-based approaches assume costly approaches, we have also invested to optimize our proposed framework. The problems of text/graphics separation are studied. We propose a method for segmenting text and non-text in document images based on a set of powerful connected component features. We applied dimensionality reduction techniques to reduce the high dimensional vector of local descriptors and approximate nearest neighbor search algorithms to optimize our proposed framework. In addition, we have also conducted experiments for a document retrieval system on the text and non-text segmented documents and ANN algorithm. The results show that the computation time of the system decreases sharply by 56% while its accuracy decreases slightly by nearly 2.5%. Overall, we have proposed an effective and efficient approach for solving the problem of logo spotting in document images. We have designed our approach to be flexible for future improvements by us and by other researchers. We believe that our work could be considered as a step in the direction of solving the problem of complete analysis and understanding of document images
LaPrise de conscience dans les environnements virtuels de collaboration : application aux interactions/manipulations distribuées collaboratives synchrones by Nabil Elmarzouqi( )

1 edition published in 2008 in French and held by 1 WorldCat member library worldwide

Les Environnements Virtuels de Collaboration (EVC) font l'objet de réflexions qui ont trait à plusieurs domaines de recherche (les systèmes distribués, la cognition, la sociologie, les interactions homme/machine. ..). L'intérêt majeur de ce type de système est la possibilité de mettre en liaison plusieurs acteurs en leur permettant d'agir l'un sur l'autre, de communiquer et de produire à travers leurs espaces de travail distribués. Cette nature complexe des collecticiels nécessite le développement de mécanismes aidant à rendre le travail réellement collaboratif. Ce travail de Thèse focalise sur l'approche de prise de conscience au sein de l'environnement de travail. L'adoption de ces mécanismes consiste, dans un premier niveau, à fournir aux participants plusieurs informations sur leur groupe, leurs collègues, les activités et les éléments constitutifs de l'environnement de travail. Par ailleurs, et afin d'assurer l'intégration de cette notion, plusieurs mécanismes sont mis en place pour le développement et l'intégration des informations de conscience. Dans ces travaux, nous contribuons par une nouvelle plateforme qui repose sur la conscience et fournit les outils nécessaires pour son incorporation dans les environnements virtuels de collaboration
Mécanismes pour la cohérence, l'atomicité et les communications au niveau des clusters : application au clustering hiérarchique distribué adaptatif by François Avril( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

To manage and handle large scale distributed dynamic distributed systems, constitutedby communicating devices that can connect or disconnect at any time, we propose to computeconnected subgraphs of the system, called clusters. We propose to compute a hierarchical structure,in which clusters of a level are grouped into clusters of the higher level. To achieve this goal,we introduce mechanisms that allow clusters to be the nodes of a distinct distributed system,that executes an algorithm. In particular, we need mechanisms to maintain the coherence of thebehavior among the nodes of a cluster regarding the higher level. By allowing clusters to be nodesof a distributed system that executes a clustering algorithm, we compute a nested hierarchicalclustering by a bottom-up approach. We formally define the distributed system of clusters, andprove that any execution of our algorithm induces an execution of the higher level algorithm onthe distributed system of clusters. Then, we prove by induction that our algorithm computes anested hierarchical clustering of the system. Last, we use this approach to solve a problem thatappears in sensor networks : collision. To avoid collisions, we propose to compute a clusteringof the system. This clustering is then used to compute a communication schedule in which twomessages cannot be sent at the same time in the range of a sensor
Medical Image Semi-fragile Watermarking in the Frequential Field by Imen Fourati Kallel( )

1 edition published in 2008 in English and held by 1 WorldCat member library worldwide

Medical imaging requires great integrity of content since any change in the image even in a slight amount might affect the diagnosis. Semi-fragile watermarking could be the best technique to provide an efficient image authentication tool for medical images. In this paper, we propose a semi-fragile watermarking technique for the tamper proofing of still images that can tolerate JPEG lossy compression to a predetermined lowest quality factor and rejects any replacement process. We also present comparison performance for the proposed algorithm to eight other common techniques
Double Watermarking and Turbo Coding for Robust Image Watermarking by Chokri Chemak( )

1 edition published in 2008 in English and held by 1 WorldCat member library worldwide

This paper is an attempt to describe the concept of double watermarking. The latter term refers to a new watermarking scheme based on embedding a mark (signature) in both spatial and multiresolution domains. This scheme is able of embedding 2000 bits of mark in medical images with dimensions 256 by 256 pixels. Experiments on a database of 30 medical images indicate the watermarks are robust to noises, filter attacks, JPEG compression, and cropping. For the purpose of increasing the image watermarking robustness against attacks of an image transmission and to perform a large number of bits to hide into images we encode with a turbo code an image-embedded mark. Fidelity of images is improved by incorporation of the relative peak signal-to-noise ratio as a perceptual metric to measure image degradation. We demonstrate by some experimental results that this unit of measurement is the best distortion metric which is correlated with the human visual system to evaluate the quality of images after the watermarking process. We show that each of these three components improves performance substantially
Elaboration de nouvelles approches basées sur les turbos codes pour augmenter la robustesse du tatouage des images médicales : application au projet PocketNeuro by Chokri Chemak( )

1 edition published in 2008 in French and held by 1 WorldCat member library worldwide

Dans la plupart des systèmes de communications sans fils, les turbos codes sont très puissants et particulièrement utiles pour la transmission sur les canaux à puissances limitées. Ce code correcteur d'erreur est très efficace pour vaincre les distorsions de transmissions. Les travaux de cette thèse consistent à intégrer le domaine du codage canal, et précisément le turbo code, au tatouage des images médicales. En effet, l'approche de tatouage d'image consiste à insérer un message dans l'image et à essayer de retrouver ce message avec le maximum de fidélité possible. Le message à insérer sera codé par le turbo code avant insertion dans l'image. Ceci a pour but de minimiser les erreurs sur le message inséré dans les images après leurs transmissions à travers les réseaux. Le premier but de cette thèse est d'élaborer de nouveaux schémas de tatouage, basés sur le turbo code, robustes contre les attaques les plus usuelles: les bruits, la compression JPEG le filtrage des images et les transformations géométriques comme le cropping. Dans ce premier but, le message inséré est considéré, comme une signature binaire qui identifie le propriétaire de l'image. Le deuxième but de la thèse est d'appliquer à la télémédecine les nouveaux schémas élaborés et ceci dans le cadre du projet PocketNeuro. Le message à insérer dans les images dans ce cas est considéré comme une information médicale relative au patient. Cette information sera codée par le turbo code puis insérée dans les images des diagnostics des patients. Deux mécanismes importants de notre contribution, la prise en charge de la confidentialité des informations médicales transmises entre les différents participants et la réalisation de l'adaptation des images aux terminaux
Etude et développement du nouvel algorithme distribué de consensus FLC permfettant de maintenir la cohérence des données partagées et tolérant aux fautess by Fouad Hanna( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Nowadays, collaborative work took a very important place in many fields and particularly in the medicaltelediagnosis field. The consistency of shared data is a key issue in this type of applications. Moreover, itis essential to use a consensus algorithm to ensure data consistency in collaborative platforms. We presenthere our new consensus algorithm FLC that helps to ensure data consistency in asynchronous collaborativedistributed systems. Our algorithm is fault tolerant and aims to improve the performance of consensus ingeneral and particularly in the case of process crashes. The new algorithm uses the leader oracle tocircumvent the impossibility result of the FLP theorem. It is decentralized and considers the crash-stop failuremodel. The FLC algorithm is based on two main ideas. The first is to perform, at the beginning of eachround, a simple election phase guaranteeing the existence of only one leader per round. The second is totake advantage of system stability and more particularly of the fact that the leader does not crash betweentwo consecutive consensus runs. The performance of our algorithm was analyzed and compared to the mostknown algorithms in the domain. The results obtained by simulation, using the Neko platform, demonstratedthat our algorithm gave the best performance when using a multicast network in the best case scenario and insituations where the algorithm undergoes one or more crashes of coordinators/leaders processes
Un nouveau protocole basé sur la réduction et l'agrandissement des images REPro (Reduction/Expansion Protocol) : appliccation : transmission et archivage pour le télédiagnostic médical by Hedi Amri( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

The exchang of medical exchange is one of the major obstacles in a telemedicine
 
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English (6)