Dissertations / Theses on the topic 'Réseau informatique local'
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Hertzog, Patrick. "Gestion des réseaux locaux industriels : application au réseau." Nancy 1, 1994. http://www.theses.fr/1994NAN10047.
Full textFreiderikos, Vasilis. "Architectures autonomiques pour le réseau local domestique." Paris 6, 2009. http://www.theses.fr/2009PA066428.
Full textBiot, Jean-Pierre. "Un système d'informations réparties sur un réseau local à diffusion." Nice, 1988. http://www.theses.fr/1988NICE4201.
Full textRafamantanantsoa, Fontaine. "Etude des performances d'un serveur web et d'un réseau local sans fil utilisant les techniques neuronales." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2009. http://tel.archives-ouvertes.fr/tel-00725472.
Full textSahin, Henriette Louise. "Contribution à l'étude du réseau numérique à intégration de services : interconnexion réseau local et autocommutateur privé (PABX) au réseau numérique à intégration de services." Toulouse, INPT, 1988. http://www.theses.fr/1988INPT011H.
Full textGeorges, Jean-Philippe. "Systèmes contrôlés en réseau : évaluation de performances d'architectures Ethernet commutées." Nancy 1, 2005. http://www.theses.fr/2005NAN10145.
Full textIn the field of networked control systems, researches have considerably evolved since Ethernet is more and more used to substitute the traditional industrial local area networks. Even if this choice of Ethernet is justified regarding its intrinsic ability to support all the communications of the enterprise (from office to workshop), it is not suitable to assume the time constraints of distributed control applications. Contrary to the fieldbuses, the non-determinism of the medium access method used by Ethernet does not enable to guarantee strict time constraints. The contribution of this thesis is to define an analytical approach to upper-bound the end-to-end delays in networked control systems which are based on switched Ethernet architectures. Work has focused on the adaptation of the network calculus theory to these specifics environments. Within this framework, this thesis presents the modeling of an IEEE 802. 1D switch as well as a computation method of the end-to-end delays based on the increasing of the traffic burstiness. Several real experiments validate the tightness of the computed bounds. In addition to the performance evaluation, the work has also considered the Classification of Service (IEEE 802. 1D/p) and the optimization of the frames scheduling on Ethernet. Finally, this thesis shows how such a performances evaluation method can be used to scale and optimize the design of switched Ethernet architectures
Méhaut, Jean-François. "Une implantation de l'architecture de système reparti OMPHALE." Lille 1, 1989. http://www.theses.fr/1989LIL10007.
Full textAdoud, Houssein. "Méthodes de partitionnement de graphes pour la conception d'architectures de réseaux locaux : sous-titre." Nancy 1, 2002. http://www.theses.fr/2002NAN10285.
Full textThe choice of topology of a communication network is a fundamental factor during the designing phase. Nowadays the topological definition of the network and its cabling plan is done in an empirical way according to the knowledge of the network expert. Thus we propose some of algorithms enabling to find an optimal topology according the volume of exchanges between the End-points (users). Two approaches are proposed according to the kinds of applications. The first one attempts to study the plans of cabling of the industrial networks. Some algorithms based on the spectral techniques of graph partitioning are proposed. The second one concerns the optimization of the design offices network topology. An analysis, of the working processes of the company, based on the metrical techniques (DSM: Design Structure Matrix) is realized. The obtained results are analyzed by means of a networks simulation tool in order to prove the interests of our propositions
Louvel, Maxime. "Architecture de gestion et de contrôle des ressources pour les applications multimédia dans le réseau local domestique." Phd thesis, Université de Bretagne occidentale - Brest, 2011. http://tel.archives-ouvertes.fr/tel-00649503.
Full textLecuire, Vincent. "Gestion des systèmes et réseaux industriels." Nancy 1, 1994. http://www.theses.fr/1994NAN10051.
Full textChen, Jinbang. "Amélioration des performances des réseaux d'entreprise." Phd thesis, Télécom ParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00982246.
Full textKrommenacker, Nicolas. "Heuristiques de conception de topologies réseaux : application aux réseaux locaux industriels." Nancy 1, 2002. http://docnum.univ-lorraine.fr/public/SCD_T_2002_0267_KROMMENACKER.pdf.
Full textIndustrial Ethernet is a controversial discussion topic mainly due to its non-determinism. Many researches focus on the improvement of Ethernet's capabilities to deliver the deterministic performance required by critical applications. Generally, that is obtained by modifying the Ethernet protocol or the traffic generated by the applications. Furthermore, the industrial context imposes a links redundancy in order to provide reliable architectures. That is why we propose to improve the switched Ethernet topology performances by optimizing the network organization at the level of the physical layer. Some graph partitioning techniques have been used in order to design optimized topologies which guarantee bounded maximum end to end delays. Two heuristics have been developed and adapted to this network design problem. The obtained results show the interest of the proposed method
Votsis, Grégoire. "Spécifications système d'un circuit VLSI contrôleur d'accès pour les réseaux locaux temps réel." Paris 11, 1986. http://www.theses.fr/1986PA112294.
Full textZins, Damien. "Le bus volubilis. Étude et développement de l'accès réseau. Gestion et analyse des performances." Nancy 1, 1990. http://docnum.univ-lorraine.fr/public/SCD_T_1990_0184_ZINS.pdf.
Full textAfilal, Foad. "Évaluation et modélisation des performances temporelles de messageries industrielles." Nancy 1, 1989. http://www.theses.fr/1989NAN10095.
Full textLorenz, Pascal. "Le temps dans les architectures de communication : application au réseau de terrain FIP." Vandoeuvre-les-Nancy, INPL, 1994. http://docnum.univ-lorraine.fr/public/INPL_T_1994_LORENZ_P.pdf.
Full textDurampart, Michel. "Régulation et médiation organisationnelles : le réseau local, enjeu d'une médiation sociale et technique dans une organisation sanitaire et sociale." Paris 13, 2000. http://www.theses.fr/2000PA131003.
Full textHernandez, Sébastien. "Evaluation et optimisation du mécanisme de Handhover dans un Réseau Local Sans Fil dédié aux applications à trafic contraint par le temps." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00703274.
Full textKhalfi, Kamel. "Contribution à la spécification d'un réseau local temps réel, au suivi de son fonctionnement, au diagnostic des pannes et à la gestion des fonctionnements dégradés." Besançon, 1989. http://www.theses.fr/1989BESA2034.
Full textFeuilloley, Laurent. "Local certification in distributed computing : error-sensitivity, uniformity, redundancy, and interactivity." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC086/document.
Full textThis dissertation is about local certification, a central topic in distributed decision, a subfield of distributed computing. The distributed decision mechanism consists, for the nodes of a network, in deciding in a distributed manner whether the network is in a proper configuration or not, with respect to some fixed predicate. This decision is said to be local because the nodes of the network can communicate only with their neighbours. After communication, every node outputs a decision, stating whether the network is locally correct, that is, correct given the partial information gathered so far by this node. The network is declared to be globally correct, if and only if, it is declared to be locally correct by every node.Most predicates cannot be verified by this type of computation, due to the locality constraint. Local certification is a mechanism that enables to circumvent this difficulty, and to check any property. It consists in providing the nodes of the network with labels, called certificates, that can be verified locally by a distributed algorithm. A local certification scheme is correct if only the networks that satisfy the predicate can be certified. In addition to its theoretical appeal, as a form of distributed non-determinism, the concept of local certification is especially relevant in the study of fault-tolerant distributed algorithms, where a key step consists in checking the status of the network, based on information stored at the nodes.This dissertation deals with four aspects of local certification: error-sensitivity, uniformity, redundancy, and interactivity. The study of these four topics is motivated by the same essential question: How to reduce the resources needed for certification, and/or ensure a better fault-tolerance? In order to tackle this question we have to understand fundamental properties of certification. In particular, in this dissertation we answer questions such as: How redundant the certificates need to be for a proper certification? Are the classic certification protocols robust to a strengthening of the acceptance condition? and, How does introducing interactivity in the process changes the complexity of certification?
Richard, Francis. "Etude des architectures optiques pour le réseau local domestique, basées sur la fibre multimode (polymère et silice) et le multiplexage en longueur d'onde." Nantes, 2012. http://archive.bu.univ-nantes.fr/pollux/show.action?id=742ac2ac-53fb-4984-837d-300038b15da6.
Full textOnly optical fiber is able to meet capacity and heterogeneity requirements of the future home network. Plastic or silica multimode fiber would be preferred for lower system costs. Two main multiformat architectures have been identified, based on an active or a passive star. Silica multimode fiber is suitable for an active star but plastic fiber could also be eligible, with its very low cost. Unfortunately, its bandwidth is far too limited. Solutions to increase its capacity, such as wavelength multiplexing, have to be investigated. In a first step, the active star is an efficient solution bringing performances and simplicity. It will be probably replaced later by a passive star combined with wavelength multiplexing, which will provide huge capacity and flexibility. This solution has been demonstrated with singlemode fiber but cost issues could lead to the use of multimode fiber, for which no specific CWDM (Coarse Wavelength Division Multiplexing) components are today available. These two issues are addressed in this thesis. Investigations are first conducted on WDM in plastic fiber, leading to admit that the state of the art does not allow significant steps in this direction. We then focused on the use of silica multimode fiber in a CWDM passive star. After experimental works, problems have been raised showing a poor uniformity of the N×N coupler when using usual CWDM sources. An original time-effective method has been proposed, based on both simulation and matrix calculation. Provided results give a better understanding of the behavior of the N×N coupler with different types of sources, taking also into account improvement techniques as offset launching or mode scrambling
Mhiri, Rawia. "Approches 2D/2D pour le SFM à partir d'un réseau de caméras asynchrones." Thesis, Rouen, INSA, 2015. http://www.theses.fr/2015ISAM0014/document.
Full textDriver assistance systems and autonomous vehicles have reached a certain maturity in recent years through the use of advanced technologies. A fundamental step for these systems is the motion and the structure estimation (Structure From Motion) that accomplish several tasks, including the detection of obstacles and road marking, localisation and mapping. To estimate their movements, such systems use relatively expensive sensors. In order to market such systems on a large scale, it is necessary to develop applications with low cost devices. In this context, vision systems is a good alternative. A new method based on 2D/2D approaches from an asynchronous multi-camera network is presented to obtain the motion and the 3D structure at the absolute scale, focusing on estimating the scale factors. The proposed method, called Triangle Method, is based on the use of three images forming a. triangle shape: two images from the same camera and an image from a neighboring camera. The algorithrn has three assumptions: the cameras share common fields of view (two by two), the path between two consecutive images from a single camera is approximated by a line segment, and the cameras are calibrated. The extrinsic calibration between two cameras combined with the assumption of rectilinear motion of the system allows to estimate the absolute scale factors. The proposed method is accurate and robust for straight trajectories and present satisfactory results for curve trajectories. To refine the initial estimation, some en-ors due to the inaccuracies of the scale estimation are improved by an optimization method: a local bundle adjustment applied only on the absolute scale factors and the 3D points. The presented approach is validated on sequences of real road scenes, and evaluated with respect to the ground truth obtained through a differential GPS. Finally, another fundamental application in the fields of driver assistance and automated driving is road and obstacles detection. A method is presented for an asynchronous system based on sparse disparity maps
Divoux, Thierry. "Étude d'un protocole d'application pour systèmes D. N. C. De niveau 2 et de sa mise en oeuvre sur module d'interface programmable." Nancy 1, 1987. http://www.theses.fr/1987NAN10162.
Full textGhernaouti, Solange. "Contribution à la normalisation des systèmes ouverts : adressage, architecture de documents, protocoles sur réseau local, un exemple d'intégration de la couche session dans un système d'exploitation." Paris 6, 1986. http://www.theses.fr/1986PA066485.
Full textBleu, Jean-Jacques. "Réseaux de télécommunication en productique : Application, intégration paramètrée des communications pour le pilotage d'ateliers flexibles." Nancy 1, 1987. http://www.theses.fr/1987NAN10371.
Full textPetit, Dorine. "Unification des stratégies de contrôle de réseau embarqué temps-réel reconfigurable." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0164/document.
Full textThis thesis is part of a long-lasting relationship between the CRAN and the CNES since 10 years. This involves studying the pertinence of replacing the buses currently embedded in European’s launchers, by off-the-shelf switched standard Ethernet architecture. Previous works qualified Ethernet regarding two quality of service items: real time and reliability. We continue this work by validating these first results on a platform, true scale architecture reproduction which will be embedded in launchers. Then, we work on an original quality of service item, typical of the spatial requirements, called observability. The objective is to re-play the whole flight, afterwards, on ground, knowing that the launcher will not come back, and the architecture is segmented, conferring to the network the dimension of non synchronized multi-domains of observation. The synthesis of all the captures implies to guarantee that the order and the freshness of launcher control information are consistent with the specified applicative operation, and that what is observed is compliant to what really happened. Finally, we propose an over-sampling which is dynamically regulated in order to benefit from the available bandwidth without disturbing real time, reconfiguration and observability requirements
Bron, Jean-Yves. "Intégration de la production : Communication entre atelier, CFAO et GPAO, application à l'entreprise CGEE Alsthom MT Nancy." Nancy 1, 1988. http://www.theses.fr/1988NAN10096.
Full textHo, Minh Tuan. "Mise en oeuvre d'un système de localisation indoor s'appuyant sur une analyse du mouvement d'un terminal embarqué." Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00997476.
Full textGarnier, Gérard. "Modélisation de protocoles : application à la couche liaison de données de F.I.P." Nancy 1, 1992. http://www.theses.fr/1992NAN10308.
Full textMolva, Refik. "Conception et realisation d'un observateur d'architectures multicouches dans les reseaux d'ordinateurs." Toulouse 3, 1986. http://www.theses.fr/1986TOU30207.
Full textAmari, Ahmed. "Conception et validation d'AeroRing - un réseau de communication Ethernet en double anneau pour les systèmes avioniques de nouvelle génération." Thesis, Toulouse, ISAE, 2017. http://www.theses.fr/2017ESAE0011/document.
Full textThe inherent complexity and bandwidth requirement of avionics communication architecturesare increasing due to the growing number of interconnected end-systems and theexpansion of exchanged data. The Avionics Full Duplex Switched Ethernet (AFDX) has beenintroduced to provide high-speed communication (100Mbps) for new generation aircraft.However, this switched network is deployed in a fully redundant way, which leads to significantquantities of wires, and thus increases weight and integration costs. To cope with thesearising issues, integrating ring-based Ethernet network in avionics context is proposed in thisthesis as a main solution to decrease the wiring-related weight and complexity. In this context,our main objective is to design and validate a new avionic communication network, calledAeroRing, based on a Gigabit Ethernet technology and supporting a Full Duplex ring topology.To achieve this aim, first, a benchmarking of the most relevant Real-Time Ethernet (RTE)solutions supporting ring topologies vs avionics requirements has been conducted, and weparticularly assess the main Performance Indicators (PIs), specified in IEC 61784-2. Thisbenchmarking reveals that each existing RTE solution satisfies some requirements better thanothers, but there is no best solution in terms of all the requirements
Cros, Olivier. "Mixed criticality management into real-time and embedded network architectures : application to switched ethernet networks." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1033/document.
Full textMC (Mixed-Criticality) is an answer for industrial systems requiring different network infrastructures to manage informations of different criticality levels inside the same system. Our purpose in this work is to find solutions to integrate gls{MC} inside highly constrained industrial domains in order to mix flows of various criticality levels inside the same infrastructure. This integration induces isolation constraints : the impact of non-critical traffic on critical traffic must be characterized and bounded. This a condition to respect timing constraints. To analyze transmission delays and focus on the determinism of transmissions, we use an end-to-end delay computation method called the trajectory approach. In our work, we use a corrected version of the trajectory approach taking into account the serialization of messages.To assure the respect of timing constraints in mixed critical networks, we first present a theoretical model of gls{MC} representation. This model is issued from gls{MC} tasks scheduling on processors. This model proposes a flow modelization which considers that each flow can be of one (low critical flows) or several criticality levels.To integrate gls{MC} inside gls{RT} networks, we propose two network protocols. The first is the centralized protocol. It is structured around the definition of a central node in the network, which is responsible for synchronizing the criticality level switch of each node through a reliable multicast protocol in charge of switching the network criticality level. This centralized protocol proposes solutions to detect the needs to change the criticality levels of all nodes and to transmit this information to the central node. The second protocol is based on a distributed approach. It proposes a local gls{MC} management on each node of a network. Each node individually manages its own internal criticality level. This protocol offers solutions to preserve when possible non-critical network flows even while transmitting critical flows in the network through weak isolation.In order to propose an implementation of these protocols inside Ethernet, we describe how to use Ethernet 802.1Q header tag to specify the criticality level of a message directly inside the frame. With this solution, each flow in the network is tagged with its criticality level and this information can be analyzed by the nodes of the network to transmit the messages from the flow or not. Additionnally, for the centralized approach, we propose a solution integrating gls{MC} configuration messages into gls{PTP} clock-synchronization messages to manage criticality configuration information in a network.In this work, we designed a simulation tool denoted as gls{ARTEMIS} (Another Real-Time Engine for Message-Issued Simulation). This tool is dedicated to gls{RT} networks analysis and gls{MC} integration scheduling scenarios. This tool, based on open and modular development guidelines, has been used all along our work to validate the theoretical models we presented through simulation. We integrated both centralized and decentralized protocols inside gls{ARTEMIS} core. The obtained simulations results allowed us to provide information about the gls{QOS} guarantees offered by both protocols. Concerning non-critical traffic : the decentralized protocol, by permitting specific nodes to stay in non-critical nodes, assures a highest success ratio of non-critical traffic correct transmission.As a conclusion, we propose solutions to integrate gls{MC} inside both industrial and gls{COTS} Ethernet architectures. The solutions can be either adapted to clock-synchronized or non clock-synchronized protocols. Depending on the protocol, the individual configuration required by each switch can be reduced to adapt these solutions to less costly network devices
Zarka, Nathalie. "Conception d'un système d'archivage électronique de documents numérisés : réalisation sur une machine SM90." Paris 6, 1986. http://www.theses.fr/1986PA066524.
Full textAhmed, Nacer Abdelaziz. "Analyse et dimensionnement de réseaux hétérogènes embarqués." Phd thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/20115/1/AHMEDNACER_Abdelaziz.pdf.
Full textStoica, Beck Alina. "Analyse de la structure locale des grands réseaux sociaux." Phd thesis, Université Paris-Diderot - Paris VII, 2010. http://tel.archives-ouvertes.fr/tel-00987880.
Full textRuskoné, Renaud. "Extraction automatique du réseau routier par interprétation locale du contexte : application à la production de données cartographiques." Marne-la-Vallée, 1996. http://www.theses.fr/1996MARN0002.
Full textCordova, David. "Étude et réalisation d’une chaîne de conversion de données pour liaisons numériques à très haut débit." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0269.
Full textThe increasing demand of higher data rates in datacenters has led tonew emerging standards (100 - 400G Ethernet and others) in wireline communications. These standards will favor more sophisticated encodings that use less frequency bandwidth. As speed requirements become more stringent, pure analog architectures can not meet them. So, a natural shift towards mixed-signal architectures is expected.This thesis proposes the design of an ADC-based receiver architecture. It uses a design methodology to define and validate the requirements and specifications for silicon-based wireline receivers that comply with >100Gb/s operation over transmission channels with high losses (>20dB). A prototype in 22nm CMOS FDSOI technology is proposed as proof of concept
Chebira, Mahmoud Sabri. "Définition d'une stratégie de gestion locale d'un réseau sans fil à contraintes d'échéances strictes et économie d'énergie." Paris 12, 2006. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990003939310204611&vid=upec.
Full textMany applications appear in different fields with the democratization of wireless networks. Most of them concern the activities of office and home automation. However, what about industrial applications? What does the market currently propose by taking into account temporal and quality constraints of connection linked to this domain? With this thesis, we propose implementations for industrial processes which request a wireless link subjected to strict temporal and energetic constraints. After a comparative study of various standards of wireless networks without thread available on the market, we opted for the latest standard 802. 15. 4 (alias ZigBee). It is designed with energy consumption saving abilities. These particularities present a real advantage for industrial automation control applications. Nevertheless, in our work, we propose few modifications within this standard at the MAC layer level which will allow a bigger flexibility regarding the management of the busy bandwidth and the guarantee of temporal deliverance of messages. This study ends with an analysis of the methods used for interconnection of network cells concerning an energetically-optimized routing technique to be developed at the level of the network layer
Ba, Ndiogou Sidy. "Passage d'un modele de connaissance regional a un modele de connaissance local des vitesses et directions du vent." Evry-Val d'Essonne, 2000. http://www.theses.fr/2000EVRY0006.
Full textBalafrej, Mohamed Amine. "Cohérences locales adaptatives dans les réseaux de contraintes." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20202.
Full textThis thesis deals with adapting the level of consistency during solving a constraint satisfaction problem (CSP). It focuses on the use of local consistency properties stronger than arc consistency (AC) to improve the CSP solving efficiency. Local consistency properties stronger than arc consistency are generally expensive to maintain in a constraint network. Therefore, these local consistencies are seldom used in practice. This thesis gives several contributions to benefit from the filtering power of local consistencies stronger than AC while avoiding the high cost of maintaining them in the whole constraint network and throughout the search. First, we introduce the parameterized local consistency (p-LC), an original approach that allows us to define intermediate levels of consistency between AC and a local consistency LC stronger than AC. Then, we present the instantiation of the parameterized local consistency approach to maxRPC and SAC, two consistencies stronger than AC. This leads to two parameterized consistencies, namely p-maxRPC and p-SAC. After giving the definitions of p-maxRPC and p-SAC, we present the algorithm p-maxRPC3, that achieves p-maxRPC and the algorithm p-SAC1, for achieving p-SAC in a constraint network. We show experimentally that maintaining an intermediate level of consistency p-LC, can give a good compromise between filtering power and the computational cost of maintaining this level of consistency. We also show that for each instance of CSP we can find a parameter that gives this good compromise. The parameterized local consistency approach does not specify how the parameter can be chosen a priori. Hence, we propose two techniques to automatically adjust the parameter p. In fact, both techniques don't use a single parameter, but several parameters. Each parameter is mapped to a part of the problem and it is automatically and locally adjusted during search. Finally, we propose POAC1, the first algorithm achieving partition-one-AC (POAC) in a constraint network. We compare POAC to SAC and we found that POAC converges faster than SAC to the fixed point due to its ability to prune values from all variable domains when being enforced on a given variable. Based on this observation, we proposed APOAC, an adaptive version of POAC, that monitors the number of variables on which to enforce POAC
Zytnicki, Matthias. "Localisation d'ARN non-codants par réseaux de contraintes pondérées." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/236/.
Full textFollowing recent discoveries about the several roles of non-coding RNAs (ncRNAs), there is now great interest in identifying these molecules. Numerous techniques have been developed to localize these RNAs in genomic sequences. We use here an approach which supposes the knowledge of a set of structural elements called signature that discriminate an ncRNA family. In this work, we combine several pattern-matching techniques with the weighted constraint satisfaction problem framework. Together, they make it possible to model our biological problem, to describe accurately the signatures and to give the solutions a cost. We conceived filtering techniques as well as novel pattern-matching algorithms. Furthermore, we designed a software called DARN! that implements our approach and another tool that automatically creates signatures. These tools make it possible to localize efficiently new ncRNAs
Mnie, Filali Imane. "Distribution multi-contenus sur Internet." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4068/document.
Full textIn this study, we focused on peer-to-peer protocols (P2P), which represent a promising solution for data dissemination and content delivery at low-cost in the Internet. We performed, initially, a behavioral study of various P2P protocols for file sharing (content distribution without time constraint) and live streaming. Concerning file sharing, we have shown the impact of Hadopi on users’ behavior and discussed the effectiveness of protocols according to content type, based on users’ choice. BitTorrent appeared as the most efficient approach during our study, especially when it comes to large content. As for streaming, we studied the quality of service of Sopcast, a live distribution network that accounts for more than 60% of P2P broadcast live events. Our in-depth analysis of these two distributionmodes led us to focus on the BitTorrent protocol because of its proven efficiency in file sharing and the fact that it is open source. In the second part of the thesis, we proposed and implemented a new protocol based on BitTorrent, in a controlled environment. The modifications that we proposed allow to increase the efficiency of the protocol through improved dissemination of metadata (the rarest piece), both for live and file sharing. An enhanced version is introduced with a push method, where nodes that lag behind receive an extra service so as to improve the overall performance
Schirrer, Maxime. "Révolution informatique et collectivités locales : quels impacts ? : l'exemple de la métropole parisienne." Paris 10, 2007. http://www.theses.fr/2007PA100058.
Full textThe prime objective of the thesis is to know if the information of the administrative services modifies the organization of the local communities. The second objective questions the repercussions in economic terms of performances and social equity. The impact study of the TIC on the level of the local institutions clarifies the emergence of a new economic area founded on the support of the economy of the networks. When the innovation is not any more the fruit of a kingly actor, but a source of differentiation, which problems are posed the leaders and the technicians of the local communities in order to distinguish and to make gravitational their territories? The analysis of case of Paris, Yvelines and Seine-et-Marne were used as test with our assumptions in order to identify variables of differentiation or convergence. The conclusions drawn from the analysis of these three departments contributed to a personal interpretation on the comprehension of spaces "postindustriels"
Meyffret, Simon. "Local and social recommendation in decentralized architectures." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00833220.
Full textBennett, Christopher H. "Apprentissage local avec des dispositifs de mémoire hautement analogiques." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS037/document.
Full textIn the next era of distributed computing, brain-based computers that perform operations locally rather than in remote servers would be a major benefit in reducing global energy costs. A new generation of emerging nonvolatile memory devices is a leading candidate for achieving this neuromorphic vision. Using theoretical and experimental work, we have explored critical issues that arise when physically realizing modern artificial neural network (ANN) architectures using emerging memory devices (“memristors”). In our experimental work, we showed organic nanosynapses adapting automatically as logic gates via a companion digital neuron and programmable logic cell (FGPA). In our theoretical work, we also considered multilayer memristive ANNs. We have developed and simulated random projection (NoProp) and backpropagation (Multilayer Perceptron) variants that use two crossbars. These local learning systems showed critical dependencies on the physical constraints of nanodevices. Finally, we examined how feed-forward ANN designs can be modified to exploit temporal effects. We focused in particular on improving bio-inspiration and performance of the NoProp system, for example, we improved the performance with plasticity effects in the first layer. These effects were obtained using a silver ionic nanodevice with intrinsic plasticity transition behavior
Guillory, Joffray. "Radio over Fiber (RoF) for the future home area networks." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1083/document.
Full textThe evolution of the Home Area Network (HAN) is lead by the proliferation of connected devices inside the home and the deployment of high broadband access network which now allows the delivery of services that can exceed 1Gbit/s. To ensure efficient in-house exchanges, the HAN has to move rapidly toward multi-Gigabit/s connections, in particular the wireless connectivity generally preferred by the customers. Current wireless systems have limited capacities, but new radio standards delivering data-rates up to 7Gbit/s are emerging. Nevertheless, as they address the unlicensed millimeter-wave band, from 57 to 66 GHz, their radio coverage is limited to a single room. Indeed, at such frequencies, the free-space losses are high and the waves do not cross the walls. This thesis proposes to solve this problem by means of the Radio over Fiber (RoF) technology. This consists in capturing the 60GHz radio signals emitted in one room, converting them into optical signals for transmission through optical fibers, and reemitting them in another room. Thus, several RoF transducers will be installed in the home and interconnected by a suitable optical infrastructure to create systems acting at the same time as repeaters and as distribution systems. From the viewpoint of the HAN market, such systems will be competitive only if they are low cost. As a consequence, this work focuses on direct modulation with direct detection (IM-DD) at Intermediate Frequency (IF). In other words, the 60GHz signal is down-converted at a lower frequency around 5GHz before the laser modulation and up-converted to 60GHz after the photodetection. Concerning the optical fiber, silica multimode fiber (MMF) is privileged as it allows the use of low cost and largely available optoelectronic devices working at 850nm.The thesis proposes different RoF architectures, from point-to-point interconnecting two rooms to multipoint-to-multipoint acting as logical buses. After an analog characterization of the optoelectronic components, the RoF link and the domestic cable, these architectures are designed, built and characterized step by step using OFDM modulation according to existing wireless 60GHz standards. Real-time transmissions between commercial devices have also been performed to validate these architectures. Moreover, advanced RoF infrastructures are proposed. First, the RoF systems can be easily improved if the access to their optical media is managed by the radio MAC layer. This approach is therefore studied showing its feasibility. Secondly, an optical system, seen by users as a premium product, has to support the legacy home services commonly used as well as the new ones that could emerge in the future. Thus, innovative multiservice and multiformat infrastructures conveying on a unique optical cable wired IP data, broadcast terrestrial or satellite television, the 60GHz wireless connectivity, and specific formats as HDMI signals are proposed and tested
Soury, Ayoub. "Approches de sûreté de fonctionnement sur Ethernet temps réel : application à une nouvelle génération d’ascenseur." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT029/document.
Full textThe design of a communication network with a real-time Ethernet-based security that meets the requirements of the PESSRAL standard, derived from IEC 61508, is the basis of our work. In order to achieve this goal, we implement mechanisms reducing the residual error probability and achieving Safety Integrity Levels (SIL) via a deterministic electronic system. Through a single communication channel, our system must be able to integrate critical and non-critical functions without compromising the system certification.According to this commitment, we suggest an industrial communication system based on real-time Ethernet. The proposed communication interfaces meet the requirements of responsiveness and determinism in order to guarantee the temporal constraints imposed by the process and the standard. To ensure the functional safety of the interfaces, we have proposed a "safety" overlay that implements security functions according to the concept of the black channel defined in IEC 61508. Based on these properties, we have managed to classify the Ethernet-based real-time solutions into three classes in terms of cycle time. The overlay "safety", based on the redundancy of data, made it possible to give up the solution of physical redundancy. This data redundancy duplicates the initial cycle time of the network, which nonetheless satisfies the security and time conditions of the standard
Robert, Jérémy. "De l'usage d'architectures Ethernet commutées embarquées dans les lanceurs spatiaux." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0128.
Full textCurrent space launchers, and particularly Ariane 5, use the deterministic network MIL-STD-1553B. According to the new objectives of cost and system mass reduction and of multimedia traffic support, this technology is not optimal anymore. Among the potential candidates, this thesis highlights the fact that such objectives can be achieved through the use of Ethernet standard based on components-on-the-shelf. The first contribution focuses on time performance evaluation of switched architectures. The gain and limits related to the communication mode (from master/slaves to producers/consummers) and future avionic distribution are studied. This study relies on a deterministic evaluation of the end-to-end delay by using network calculus, simulations and experiments. These results are validated with two switched architectures by using a scenario considered as representative of current flights. The second contribution is the network availability improvement. A real-time path reconfiguration strategy is proposed through active network supervision. Based on critical requirements, it is also suggested to use multiple spanning-trees for anticipating network element failures. The last contribution deals with the issue that in switched and segmented architectures it is not possible to collect all the traffic as in a bus. In order to do so, this thesis introduces the configurations under which a clock synchronization protocol could contribute to generate a single network trace from many collecting points. This work will enable to identify the tests for a future Ethernet standard validation in the framework of space launchers
Trabelsi, Kods. "Métaheuristiques pour la synthèse de haut niveau." Université européenne de Bretagne, 2009. http://www.theses.fr/2009LORIS158.
Full textThis dissertation presents a study at the cross-road of the operational research's area and the high level synthesis's one. If considering current state-of-the-art methods for automated integrated circuits design, it is clear that new solutions for design flow must be found, to reply to the very fast growth of the digital technology market. High level synthesis tools appear to bridge the gap between modeling architecture and the actual achievement of the integrated circuit. Thus, given a C/C++ specification of an application, its associated throughput constraint, and the target goal, high-level synthesis tools allows to generate automatically an RTL architecture. However, the solutions provided by the high-level synthesis are not always area efficient, due to current selection of search algorithms. In this dissertation we propose several new approaches to explore the solutions space. Yet, to find the real architecture area, we have to pass by the logical synthesis. But this way is very expensive in computing time. So we propose also an architecture area estimation technique, based on an array giving the different components of the architecture and a library characterizing notably the different components on area. The search approaches we propose, includ a simple descent, deepest descent, a variable neighborhood search, a multi starts descent and finally a dedicated Greedy Randomized Adaptive Search Procedure which all aiming at minimizing the global area. We show through a set of test cases that our approach offers significant gain relative to the state-of-the-art
Marzougui, Taher. "Réduction du coût énergétique d'un réseau d'irrigation agricole : optimisation de la facture, diagnostic de fuites et production énergétique locale à base des énergies renouvelables." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0742/document.
Full textWater is abundant on earth, however, it is not evenly distributed on the globe. Thus, water distribution systems have been designed to meet different needs. In this context, to make fertile lands above the source, irrigation networks were implemented by operating pumping systems. However, pressurized networks are a source of huge energy expenditures and water losses that represent important economic issues. This is a major challenge for optimizing energy expenditure. The present thesis aims to analyze the energy cost of an irrigation network with application to the Carpentras canal.The objective of this work is to minimize the energy expenditure of the network. To do so, three approaches have been explored. Firstly, a study focused on the optimization of electricity contracts from an administrative point of view. The aim was to propose a methodology to optimize the cost of the electricity bill by acting on elements chosen by the operator. Secondly, a methodology for the detection and localization of possible leaks, in the irrigation network, is proposed. This method is based on the analysis of the circulation of water. Finally, a part was dedicated to the sizing of an energy production system based on the use of renewable sources