Dissertationen zum Thema „Réseaux hétérogène“
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Louge, Robert. „Un système de gestion réseau hétérogène en milieu industriel“. Toulouse 3, 1992. http://www.theses.fr/1992TOU30158.
Der volle Inhalt der QuelleSalazar, Gaitàn Oscar. „Statégies de roaming inter-opérateur dans un réseau mobile hétérogène“. Paris, ENST, 2007. https://pastel.hal.science/pastel-00003796.
Der volle Inhalt der QuelleIn a future, existing wireless access technologies such as WiFi (Wireless Fidelity), WiMAX (Worldwide Interoperability for Microwave Access) and UMTS (Universal Mobile Telecommunication System) will coexist on daily basis. Nevertheless, this daily coexistence does not imply that they will be able to fully interoperate. Thus, my research work focuses on a specific roaming scenario which is formed by heterogeneous wireless access networks managed by different operators. Our main objective is to provide a seamless (for the mobile user) roaming architecture to enable network interoperability under a heterogeneous multi-operator wireless environment, all this without major changes in current wireless architectures. In this regard, we also aim at reducing the roaming signaling exchange caused by the authentication and authorization mechanisms in the network registration and session initiation process while providing robust network security. The results obtained through computer simulation indicated that the use of our approach reduces significantly the network registration and session initiation delay, hence outperforming the traditional Roaming-SIP method. We also confirmed that the wireless delay introduced by the VN increases considerably when increasing the traffic congestion level in the Visiting Networks. Thus, from the simulations results we can state that by reducing the signaling message exchange, and maintaining acceptable congestion levels in the wireless network, hence reducing the wireless transmission delay, we can improved the overall de-lay in both network registration and session initiaition process
Delahaye, Jean-Philippe. „Plate-forme hétérogène reconfigurable : application à la radio logicielle“. Rennes 1, 2007. http://www.theses.fr/2007REN1S181.
Der volle Inhalt der QuelleThe Software Defined Radio (SDR) techniques aim at offering an access to a broad choice of radio communications standards on a flexible hardware (HW) architecture which is necessary in order to answer the diversity of the processing to carry out. The digital communications techniques involve heterogeneous resources needs. The reconfigurability of a heterogeneous HW platform is thus a key features to a successful appearance of SDR systems. The reconfigurability of a SDR system must meet the needs for adaptation of the processing functions to answer the requirements of the contexts switching. Our work is based on the analysis of the baseband processing in the transmitting chains of the 3 standards UMTS, GSM and 802. 11g. We propose an analysis of factorization of the multistandard baseband processing in order to reduce the number of contexts to be managed and we determine the needs for flexibility of SDR applications. In this context, the configuration management of HW platforms clearly appears as the key feature of a SDR system. We propose a Hierarchical and Distributed Configuration Management (“HDCM”) approach in order to meet the needs of managing various types of flexibility of dataflow oriented applications mapped on heterogeneous HW. The implementation of applications on reconfigurable heterogeneous platforms and in particular on configurable logic devices, requires the uses of new design methodologies in order to extract the potential reconfigurability of these reconfigurables devices. We bring in this work various design methodologies that aim at designing partially and dynamically reconfigurable systems on chip and on FPGA
Viéron, Jérôme. „Codage scalable et contrôle de congestion pour transmission vidéo sur réseaux hétérogène“. Rennes 1, 2003. https://hal.archives-ouvertes.fr/tel-01131930.
Der volle Inhalt der QuelleAlassir, Mohamad Dib. „Modélisation au niveau système des entrées/sorties d'un système hétérogène“. Paris 6, 2010. http://www.theses.fr/2010PA066005.
Der volle Inhalt der QuelleGonzalez, santamaria Carlos. „Gestion d'une architecture hétérogène distribuée à l'aide du SDN“. Thesis, Reims, 2017. http://www.theses.fr/2017REIMS037/document.
Der volle Inhalt der QuelleRecently, the giants of the Internet are adopting every day more and more the benefits of virtualization within the data center. Each virtualized application and its operating system can run simultaneously from one physical device. This technology reduces significantly power consumption, energy consumption, as well as operational cost. Furthermore, not long ago, this promising solution is studied by the research communities to be extended for network virtualization deployment. In traditional network physical device like routers and/or switches are responsible to transfer the information from one point to another, following the instructions previously programmed by a network administrator. At this time, the physical networking devices can be virtualized, providing an intelligent abstraction via virtual network software that makes easy to deploy and manage network resources. The search giant Google has deployed SDN to experiment with the inter-connection between their data center around the world [1].With the exponential growth of devices connected to the Internet, security network is one of the hardest challenge for network managers. Maintaining and securing such large scale and heterogeneous network is a challenging task. In this context, the new networking paradigm, the Software Defined Networking (SDN), introduces many opportunities and provides the potential to overcome those challenges. In our approach, we first propose a new SDN based architecture for networking with or without infrastructure, that we call an SDN domain. This domain includes wired network, wireless network and Ad-Hoc networks. Next, a second architecture includes sensor networks in an SDN-based network and in a domain. Third, interconnecting multiple domains and we describe how we can enhance the security of each domain and how to distribute the security rules in order not to compromise the security of one domain. Finally, we present a new secure and distributed architecture for ad-hoc networks and IoT (Internet of Things)
Le, Guellaut Christophe. „Prototypage d’un système MIMO-MC-CDMA sur plateforme hétérogène“. Rennes, INSA, 2009. https://tel.archives-ouvertes.fr/tel-00419176.
Der volle Inhalt der QuelleThis thesis deals with the implementation of communication systems into a SUNDANCE heterogeneous latform, composed of DSPs and FPGAs in the context of convergence of local area networks and cellular networks. The hysical layer of our system is based on MIMO-MC-CDMA with two transmit antennas and two receive antennas. IMO-MCCDMA combines spectrum spreading, OFDM, and Alamouti space-time coding, so that it benefits from frequency diversity and spatial diversity. Our work leads to the implementation of the baseband transmitter, including start of frame detection and channel estimation. Studies concerning the radiofrequency stages are presented. Our baseband implementation raises the question of the hardware requirements for next generation wireless networks. To this end, we have proposed a very efficient transmitting scheme for MIMO-OFDM systems. Besides, a new application has been designed to promote our platform
Komarova, Maryna. „Authentification rapide et contrôle d'accès basé sur la confiance dans les réseaux sans fil hétérogène“. Phd thesis, Télécom ParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00003793.
Der volle Inhalt der QuelleSchweitzer, Benjamin. „Modélisation d’effets de solvant pour des réseaux réactionnels étendus de la biomasse en catalyse hétérogène“. Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN019.
Der volle Inhalt der QuelleThis thesis focuses on multi scale simulations heterogeneous catalysis reactions of polyols on platinum (111) in aqueous phase. This work is about lignocellulosic biomass valorisation. The reaction networks raising from these materials are extremely large and complex. Also, the properties of the molecules forming this biomass make aqueous conditions mandatory. Ab initio methods as we know them forbids us to treat entire networks at the finest calculation level, the computational cost would be way beyond feasibility. Changing the simulation scale can tackle this problem. Thus, we developed a group additivity model assessing for thermochemical properties of polyols at a platinum (111) surface under aqueous conditions, with a topology as the only input. This model was built upon a density functional theory set. Kinetics of reactions was also covered, and the difference in terms of impact was investigated between implicit and explicit micro solvation models, in order to predict reaction barriers. The two models might be used together in order to feed a micro kinetic simulation, allowing a drastic decrease of reaction networks complexity. Finally, the influence on reactivity and selectivity, of hydroxyl groups on butanediol isomers was investigated
Michel, Cedric. „Langage de description d'attaques pour la détection d'intrusions par corrélation d'évènements ou d'alertes en environnement réseau hétérogène“. Rennes 1, 2003. https://tel.archives-ouvertes.fr/tel-01271855.
Der volle Inhalt der QuelleBoutabia, Mohammed. „Continuité de service dans les réseaux sans fils hétérogènes pour les applications à contrainte de temps“. Phd thesis, Institut National des Télécommunications, 2011. http://tel.archives-ouvertes.fr/tel-00594726.
Der volle Inhalt der QuelleAchour, Amel. „Gestion de la mobilité pour les terminaux multi-homés dans un environnement sans-fil hétérogène“. Paris 6, 2012. http://www.theses.fr/2012PA066344.
Der volle Inhalt der QuelleIn the current environment, wireless networks are widely deployed, several technologies coexist, each of them response to a particular issue. These technologies have coexist to provide the best services to users. Moreover, the emergence of multi-interface mobile terminals (3G, WLAN, WMAN, etc. . ) has completely changed the vision of IP services. A mobile terminal is able to access services provided by their ISPs anywhere, any-time and most importantly, through any available access network according to the concept "Always Best Connected" (ABC). In order to take full advantage of this heterogeneous environment, the concept of ABC will be extended to the simultaneous use of different access networks. This new generation of communication systems is commonly called "multi-homing". In this context, different technologies, cellular, wireless LAN and wired networks coexist. Moreover, the generalization the heterogeneous environment has led operators to consider the combination of these different technologies, with the objective of offering better services to users. However, such a combination raises many issues such as the sessions control, authentication, QoS, user mobility. . . Etc, therefore, the current trend tends to offer an all IP network to facilitate this convergence. The IMS is a promising solution, which allows the convergence of heterogeneous networks and their interconnection with a management that is totally independent of the access network. This thesis studied the proposals for the multi-homing, and the mobility management for multi-homed terminals. It is interested in solutions based on the terminal, and the protocol SHIM6. It proposes an extension allowing the terminals implementing SHIM6 to have a simultaneous access to different access networks, which guarantee the application to have the best available access network. Subsequently, a study of mobility in this context is presented. Test-bed is set up to evaluate and validate these proposals, demonstrating their feasibility in a real environment. Now the simultaneous access is established, the second part of this thesis focuses on mobility management with guaranteed quality of service for current sessions. To achieve this, the proposed solution combines the protocol SHIM6 with IMS. The protocol SHIM6's role is the mobility management, and thus the change of access networks, seamlessly, while IMS ensures quality of service of established sessions. Two modes of mobility are studied: reactive and proactive. We also studied the inter-domain mobility and intra-domain. In both cases, a test-bed is set up to validate the proposals. The results show a significant reduction in the handover period, particularly in the proactive mode. The proposed solutions are based on the terminal, we evaluated their performance impact of the latter
Rahil, Ahmad. „Gestion du Handover dans les réseaux hétérogènes mobiles et sans fil“. Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS006/document.
Der volle Inhalt der QuelleSince 1990, networking and mobile technologies have made a phenomenal unprecedented progress. This progress has been experienced on multiple fronts in parallel; especially on the application level and the user's needs one. This rapid evolution of the technology imposed a need for the existence of heterogeneous environments where the coverage is ensured throughout the different available networks. The challenge with such architecture would be to provide the user with the ability to navigate through the different available networks in a transparent and seamless fashion. However, the navigation among different types of networks is commonly referred to as vertical Handover. The IEEE 802.21 standard offers a component that is called Media Independent Handover (MIH) which has a function that provides the capability of transmitting the state of the connection of the mobile nodes from the lower to upper layers. This layer would exist between layer 2 and layer 3 within the protocol architecture. The main role of MIH is to help the mobile node transfer without interrupt among different types of networks, but the logic of selection is left without implementation. In this context, we worked on the improvement of the Handover management by proposing a new architecture, called VHMC and based on MIH by offering new methods for selecting the destination network. The first solution is a new algorithm called Multiple Criteria Selection Algorithm (MCSA) based on multiple parameters of the quality of service. We used Network Simulator (NS2) for testing our approach and study the number of lost packets and lost time during Handover. The second solution is a new model for selecting the destination network based on fuzzy logic techniques. The distinctive characteristic of this model lies in the study of genuine Handover records taken from a Lebanese mobile operator called "Alfa". A third proposed solution for network selection is based on multiple linear regression theory
Tricot-Censier, Pascal. „Étude et réalisation d'une passerelle entre un réseau MIL1553 et un réseau ETHERNET : implantation du réseau homogène OS9NET et du réseau hétérogène TCP/IP sur le système d'exploitation temps réel OS-9/68000“. Paris 11, 1989. http://www.theses.fr/1989PA112241.
Der volle Inhalt der QuelleDechelotte, Jonathan. „Etude et mise en oeuvre d'un environnement d'exécution pour architecture hétérogène reconfigurable“. Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0025.
Der volle Inhalt der QuelleToday, embedded systems have taken a leading role in our world. Whether for communication, travel, work or entertainment, their use is preponderant. Together, research and industry efforts are constantly developing various parts that make up these systems: processor, FPGA, memory, operating system.From an architectural point of view, the contribution of a generalist architecture coupled with a reconfigurable architecture positions SoC FPGA as popular targets for use in embedded systems. However, their implementation's complexity makes their adoption difficult. The abstraction of low-level layers seems to be an investigation's axis that would tend to reverse this trend. The use of an operating system seems suitable at first glance because they deliver an ecosystem of drivers and services for access to hardware resources, native scheduling capacities and libraries for security. However, this solution brings constraints and lead to evaluate other approaches.This manuscript evaluates the ability of a high-level language, Lua, to provide an execution environment in such a case that the implementation does not provide operating system. It gives, through an ecosystem named Lynq, the necessary building blocks for the management and allocation of resources present on the SoC FPGA as well as a method for isolation between applications. Besides the adoption of this execution environment, our work explores the capacity of generalist architectures such as CPUs to become specialized when implemented on a FPGA. This is done through a contribution allowing the generation of a RISC-V CPU and its associated microcode
Wicaksana, Arief. „Infrastructure portable pour un système hétérogène reconfigurable dans un environnement de cloud-FPGA“. Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT088/document.
Der volle Inhalt der QuelleField-Programmable Gate Arrays (FPGAs) have been gaining popularity as hardware accelerators in heterogeneous architectures thanks to their high performance and low energy consumption. This argument has been supported by the recent integration of FPGA devices in cloud services and data centers. The potential offered by the reconfigurable architectures can still be optimized by treating FPGAs as virtualizable resources and offering them multitasking capability. The solution to preempt a hardware task on an FPGA with the objective of context switching it has been in research for many years. The previous works mainly proposed the strategy to extract the context of a running task from the FPGA to provide the possibility of its resumption at a later time. The communication during the process, on the contrary, has not been receiving much attention.In this work, we study the communication management of a hardware task whileit is being context switched. This communication management is necessary to ensure the consistency in the communication of a task with context switch capability in a reconfigurable system. Otherwise, a hardware context switch can only be allowed under restrictive constraints which may lead to a considerable penalty in performance; context switching a task is possible after the communication flows finish and the input/output data have been consumed. Furthermore, certain techniques demand homogeneity in the platform for a hardware context switch can take place.We present a mechanism which preserves the communication consistency during ahardware context switch in a reconfigurable architecture. The input/output communication data are managed together with the task context to ensure their integrity. The overall management of the hardware task context and communication data follows a dedicated protocol developed for heterogeneous reconfigurable architectures. This protocol thus allows a hardware context switch to take place while the task still has ongoing communication flows on Reconfigurable System-on-Chips (RSoCs). From the experiments, we discover that the overhead due to managing the communication data becomes negligible since our mechanism provides the necessary high responsiveness for preemptive scheduling, besides the consistency in communication. Finally, the applications of the proposed solution are presented in a task migration prototyping and in a hypervisor-based system
Wetterwald, Michelle. „Contrôle de terminaux multi-modes autonomes dans des environnements sans fil hétérogènes et indépendants“. Thesis, Paris, ENST, 2012. http://www.theses.fr/2012ENST0064/document.
Der volle Inhalt der QuelleRecent years have witnessed a massive evolution of mobile communications. When no agreement between the network providers exists, changing the attached network still means breaking the session and relying on the application to recover the lost data. In parallel, it is hardly possible for a mobile user to control the connectivity of his terminal. The objective of this thesis is to present the concept of an innovative technological framework for the autonomous control of multimode terminals in heterogeneous and non-federated wireless environments. The aim is to enable a self-configuring terminal to connect and roam seamlessly across independent networks, while respecting its user’s choices and preferences. The target scheme involves abstraction and cross-layer mechanisms. It takes into account constraints based on heterogeneous wireless systems, autonomous architectures and enables generic services such as smart access network selection, connectivity and session management. This scheme applies to the mobile terminal, with mechanisms independent of the network infrastructure. The thesis analyses how existing technologies are enhanced and combined with new features to achieve this objective and gives a description of the overall concept and of its implementation. A simulated model is used to assess the validity of the proposed framework. Diverse applications to real systems that implemented the components of this framework are presented, highlighting the generality and key benefits of the concept
Cavalcante, Aguilar Paulo Armando. „Réseaux Évidentiels pour la fusion de données multimodales hétérogènes : application à la détection de chutes“. Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00789773.
Der volle Inhalt der QuelleBoutabia, Mohammed. „Continuité de service dans les réseaux sans fils hétérogènes pour les applications à contrainte de temps“. Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2011. http://www.theses.fr/2011TELE0011.
Der volle Inhalt der QuelleService continuity is an important component in mobile communications. With the coexistence of different access network technologies and the emergence of multi-interface mobile devices, service providers should maintain the ongoing communication when the mobile travels among heterogeneous networks. Services like IPTV, video on demand or voice over IP are widely proposed by operators for which service continuity should be guaranteed. This thesis is devoted to service continuity of real-time applications in heterogeneous networks. We tackle this problem from two perspectives: session mobility and terminal mobility. Although these two mechanisms have the same purpose which is ensuring service continuity when changing the terminal or the access network, each technique has its own challenges and constraints. As far as session mobility is concerned, a new signaling protocol has been proposed to transfer the session between different terminals. This protocol has been implemented in video streaming scenarios and evaluated in a testbed. Moreover, we address the problem of media adaptation, especially renegotiation of QoS parameters since session might be transferred to a new terminal with different capabilities than the original one. QoS renegotiation can be extended to cover the case where some internal parameters are degraded during the session in the same terminal. For terminal mobility, we propose a new handover mechanism using IEEE802.21 with Fast handover for Mobile IPv6. The purpose of this proposal is to reduce the handover delay and the dedicated buffer in access routers. In addition, an optimization is proposed for Fast handovers for Mobile IPv6 in order to maximize the probability of its predictive mode. In the same context, mobility in IMS is considered and an appropriate solution is proposed to answer IMS requirements. Finally, we conduct a comparison study between different mobile IP variants in the case of vertical handover. Based on this comparison, we give some guidelines that should help in choosing the most efficient protocol following specific parameters. The proposed solutions and studies have been evaluated analytically or/and using a simulation tool
Wang, Lusheng. „Sélection de réseau dans les réseaux sans fil hétérogènes“. Phd thesis, Paris, ENST, 2010. https://pastel.hal.science/pastel-00517219.
Der volle Inhalt der QuelleIn the present trend towards ubiquity of networks and mobility of services, we observe that network access can be provided by different types of access technologies with coverage overlapping, which composes an environment of heterogeneous wireless networks. In this environment, mobile terminals need always select the best network. In this dissertation, we make firstly a survey of existing schemes of network selection, which utilise different mathematical models. Then, we establish a simulator by matlab. In our first proposition, the problem of using mobility factors are studied. We explain that the selection of the best network becomes the selection of the best permutation when vertical handover properties are taken into account. In the end, we propose a scheme to find the best permutation. Secondly, we analyze the requirement of new subjective weighting method. We propose a new automatic method, which is based on the triggers and is capable of calculating efficiently subjective weights of various attributes, considering terminal and network factors. Finally, many other problems of network selection are analyzed and possible solutions are proposed. Based on all the above studies, we propose an integrated strategy for network selection
Wang, Lusheng. „Sélection de Réseau dans les Réseaux Sans Fil Hétérogènes“. Phd thesis, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00517219.
Der volle Inhalt der QuelleWetterwald, Michelle. „Contrôle de terminaux multi-modes autonomes dans des environnements sans fil hétérogènes et indépendants“. Electronic Thesis or Diss., Paris, ENST, 2012. http://www.theses.fr/2012ENST0064.
Der volle Inhalt der QuelleRecent years have witnessed a massive evolution of mobile communications. When no agreement between the network providers exists, changing the attached network still means breaking the session and relying on the application to recover the lost data. In parallel, it is hardly possible for a mobile user to control the connectivity of his terminal. The objective of this thesis is to present the concept of an innovative technological framework for the autonomous control of multimode terminals in heterogeneous and non-federated wireless environments. The aim is to enable a self-configuring terminal to connect and roam seamlessly across independent networks, while respecting its user’s choices and preferences. The target scheme involves abstraction and cross-layer mechanisms. It takes into account constraints based on heterogeneous wireless systems, autonomous architectures and enables generic services such as smart access network selection, connectivity and session management. This scheme applies to the mobile terminal, with mechanisms independent of the network infrastructure. The thesis analyses how existing technologies are enhanced and combined with new features to achieve this objective and gives a description of the overall concept and of its implementation. A simulated model is used to assess the validity of the proposed framework. Diverse applications to real systems that implemented the components of this framework are presented, highlighting the generality and key benefits of the concept
Autefage, Vincent. „Découverte de services et collaboration au sein d'une flotte hétérogène et hautement dynamique d'objets mobiles communicants autonomes“. Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0205/document.
Der volle Inhalt der QuelleWe call autonomous systems, mobile and communicating objects which are able to perform several tasks without any human intervention. The overall cost (including price, weight and energy) of the payload required by some missions is sometimes too important to enable the entities to embed all the required capabilities (i.e. sensors and actuators). This is the reason why it is more suitable to spread all the capabilities among several entities. The team formed by those entities is called a swarm. It then becomes necessary to provide a discovery mechanism built into the swarm in order to enable its members to share their capabilities and to collaborate for achieving a global mission.This mechanism should perform task allocation as well as management of conflicts and failures which can occur at any moment on any entity of the swarm. In this thesis, we present a novel collaborative system which is called AMiRALE for heterogeneous swarms of autonomous mobile robots. Our system is fully distributed and relies only on asynchronous communications. We also present a novel tool called NEmu which enables to create virtual mobile networks with a complete control over the network topology, links and nodes properties. This tool is designed for performingrealistic experimentation on prototypes of network applications. Finally, we present experimental results on our collaborative system AMiRALE obtained through a park cleaning scenario which relies on an autonomous swarm of drones and specialized ground robots
Jabban, Ahmad. „Optimisation et analyse des résesaux intelligents et des réseaux hétérogènes“. Phd thesis, INSA de Rennes, 2013. http://tel.archives-ouvertes.fr/tel-00881045.
Der volle Inhalt der QuelleChen, Langshi. „Méthode de Krylov itératives avec communication et efficacité énergétique optimisées sur machine hétérogène“. Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10114/document.
Der volle Inhalt der QuelleIterative methods are frequently used in extremely large scale linear problems, such solving linear systems or finding eigenvalue/eigenvectors of matrices. As these iterative methods require a substantial computational workload, they are normally deployed on large clusters of distributed memory architectures communicated via MPI. When the problem size scales up, the communication becomes a major bottleneck of reaching a higher scalability because of two reasons: 1) Many of the iterative methods rely on BLAS-2 low level matrix vector kernels that are communication intensive. 2) Data movement (memory access, MPI communication) is much slower than processor's speed. In case of sparse matrix operations such as Sparse Matrix Vector Multiplication (SpMV), the communication even replaces the computation as the dominant time cost. Furthermore, the advent of accelerators/coprocessors like Nvidia's GPU make computation cost more cheaper, while the communication cost remains high in such CPU-coprocessor heterogeneous systems. Thus, the first part of our work focus on the optimization of communication cost of iterative methods on heterogeneous clusters. Besides the communication cost, power wall becomes another bottleneck of future exascale computing in recent time. Researches indicate that a power-aware algorithmic implementation strategy could efficiently reduce the power dissipation of large clusters. We also explore the potential energy saving implementation of iterative methods in our experimentation. Finally, both the communication optimization and energy efficiency implementation would be integrated into a GMRES method, which demands an auto-tuning framework to maximize its performance
Risser, Laurent. „Analyse quantitative de réseaux micro-vasculaires intra-corticaux“. Toulouse 3, 2007. http://www.theses.fr/2007TOU30011.
Der volle Inhalt der QuelleThis work is a quantitative investigation of intra-cortical micro-vascular networks using a new micro-tomography imaging protocol which permits a complete scan of the entire gray matter with a micron resolution. The first part of the PhD is devoted to the analysis of very large 3D images coming from healthy rats and marmosets primate cortex, as well as tumour implanted rats brains. Classical methods are used for binarisation and squeletonization of the images. The influence of the experimental protocol on the obtained images is evaluated. A fast and original method is proposed to fill the gaps of incompletely injected vessels the efficiency of which is tested and validated. The second part of the PhD is concerned by the statistical analysis of geometrical, local and topological properties of micro-vascular networks. Geometrical properties are related to the spatial distribution of vessels from studying the vascular density and the vessel/tissue distance map. We brought to the fore the multi-scale properties of those fields from fractal and spectral analysis up to a some cut-off which defines the typical length-scale of an elementary representative volume. We found that this length-scale significantly differ in normal and tumoral tissues. The local analysis of vessel's segment length systematically exhibits exponential distribution, which leads to some characteristic segments length. Those length significantly differ in adult and new-born primates tissues. This analysis is consistent with the result obtained on the vascular density and leads to the conclusion that developmental angiogenesis occurs mainly at the capillary scale. .
Zatout, Youssouf. „Conception et évaluation de performances d'un réseau de capteurs sans fil hétérogène pour une application domotique“. Phd thesis, Université Toulouse le Mirail - Toulouse II, 2011. http://tel.archives-ouvertes.fr/tel-00632228.
Der volle Inhalt der QuelleRachdi, Mohamed Anouar. „Optimisation des ressources de réseaux hétérogènes avec coeur de réseau MPLS“. Phd thesis, INSA de Toulouse, 2007. http://tel.archives-ouvertes.fr/tel-00146229.
Der volle Inhalt der QuelleSouissi, Omar. „Planification de chemin d'hélicoptères sur une architecture hétérogène CPU FPGA haute performance“. Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0003.
Der volle Inhalt der QuelleSecurity issues are today a key-differentiator in the aviation sector. Indeed, it comes to ensure the safety of expensive equipments but above all to save human lives. In this context, it is necessary to offer an important level of autonomy to helicopters. Although some studies have been carried out in this area, the dynamic generation of a sequence of maneuvers under hard time constraints in an unknown environment still represents a major challenge for many academic and industrial working groups. AIRBUS HELICOPTERS as a leader of helicopters manufacturing, looks forward to integrate an assistance system for mission re-planning in the next generation of aircrafts.The work conducted in this PhD thesis falls within a collaboration between AIRBUS HELICOPTERS and UNIVERSITE DE VALENCIENNES ET DU HAINAUTCAMBRESIS. One of the main purposes of this work is efficient flight plan generation. Indeed, for intelligent assistant systems we need to generate a new path planning inorder to face emergency events such as an equipment failure or adverse weather conditions. The second major objective of this work is the deployment of mission planning tasks onto a high performance architecture CPU/FPGA in order to meet real-time requirements for the dynamic optimization process. In the present work, we first studied efficient flight plan generation. Indeed, we developed efficient and effective algorithms for helicopter path planning. Then, in order to obtain a real-time system, we resolved the problem of scheduling optimization on a heterogeneous architecture CPU / FPGA by proposing several scheduling methods including exact approaches and heuristics
Sapountzis, Nikolaos. „Optimisation au niveau réseau dans le cadre des réseaux hétérogènes nouvelle génération“. Electronic Thesis or Diss., Paris, ENST, 2016. http://www.theses.fr/2016ENST0082.
Der volle Inhalt der QuelleBy 2016, it is well-known that mobile networking has dominated our lives. We use our mobile cell phones for almost everything: from social networking to streaming, finding accommodation or banking. Nevertheless, it seems that operators have not understood yet this domination, since their networks consist of nodes that: (i) suffer from enormous load fluctuations, (ii) waste their resources, and (iii) are blamed to be a major energy-killer worldwide. Such shortcomings hurt: load-balancing, spectral and energy efficiency, respectively. The goal of this dissertation is to carefully study these efficiencies and achieve a good trade-off between them for future mobile 5G heterogeneous networks (HetNets). Towards this direction, we firstly focus on (i) the user and traffic differentiation, emerging from the MTC and IoT applications, and (ii) the RAN. Specifically, we perform appropriate modeling, performance analysis and optimization for a family of objectives, using tools mostly coming from (non) convex optimization, probability and queueing theory. Our initial consideration is on network-layer optimizations (e.g. studying the user association problem). Then, we analytically show that cross-layer optimization is key for the success of future HetNets, as one needs to jointly study other problems coming from the layers below (e.g. the TDD allocation problem from the MAC, or the cross-interference management from the PHY) to avoid performance degradation. Finally, we add the backhaul network into our framework, and consider additional constraints related to the backhaul capacity, backhaul topology, as well as the problem of backhaul TDD allocation
Maviel, Laurent. „Modélisation et simulation des réseaux sans fil hétérogènes et non-stationnaires : Application aux topologies de petites cellules“. Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00942972.
Der volle Inhalt der QuelleNguyen, Huu-Nghia. „Gestion de Mobilité Supportée par le Réseau dans les Réseaux Sans Fil Hétérogènes“. Phd thesis, Télécom ParisTech, 2009. http://pastel.archives-ouvertes.fr/pastel-00005406.
Der volle Inhalt der QuelleNguyen, Huu Nghia. „Gestion de mobilité supportée par le réseau dans les réseaux sans fil hétérogènes“. Paris, ENST, 2009. https://pastel.hal.science/pastel-00005406.
Der volle Inhalt der QuelleIn this thesis, we focus on challenges to support Proxy Mobile IPv6 (PMIPv6) in heterogeneous wireless networks, of which the topology can be statically defined but more likely to be arbitrary and organized as spontaneous wireless mesh networks. We first propose the cluster-based architecture to scale up the network. Subsequently, we propose an extension to PMIPv6 for scalability support in large wireless networks in a cluster-based manner. We have evaluated the scalability of our framework, called Scalable Proxy Mobile IPv6 (SPMIPv6), in a wireless mesh network context. A mathematical model has been used to investigate the scalability of the framework with consideration of the wireless mesh network size, mobile node density, and average mobile speed. Furthermore, we introduce route optimization support into the SPMIPv6 framework, and then propose an enhanced IP-Layer network-based movement detection mechanism to deal with an environment employing heterogeneous radio access technologies. In order to evaluate the performance of these extensions, we implement all these propositions under Linux. We setup both virtual and real wireless mesh testbeds and run each in different scenarios to evaluate important information, such as signaling cost, handover latency, packets loss, Round Trip Time (RTT), and TCP throughput. Finally, we address the multi-homing context by proposing a virtual Stream Control Transmission Protocol (vSCTP) tunneling method, which is beneficial for both users and operators with wireless bandwidth aggregation and load balancing scenarios
Ben, Aoun Cédric. „Principes et réalisation d'un environnement de prototypage virtuel de systèmes hétérogènes composables“. Electronic Thesis or Diss., Paris 6, 2017. http://www.theses.fr/2017PA066160.
Der volle Inhalt der QuelleCurrent and future microelectronics systems are more and more complex. In a aim to bridge the gap between the cyber world and the physical world we observe the emergence of multi-disciplinary systems that interact more and more with their close surrounding environment. The conception of such systems requires the knowledge of multiple scientific disciplines which tends to define them as heterogeneous systems. Designers of the upcoming digital-centric systems are lacking a common design and simulation environment able to manage all the multi-disciplinary aspects of its components of various nature, which closely interact with each other. We explore the possibilities of developing and deploying a unified SystemC-based design environment for virtual prototyping of heterogeneous systems. To overcome the challenges related to their specification and dimensioning this environment must be able to simulate a heterogeneous system as a whole, for which each component is described and solved using the most appropriate MoC. We propose a simulator prototype called SystemC MDVP which is implemented as an extension of SystemC. It follows a correct-by-construction approach, relies on a hierarchical heterogeneity representation and interaction mechanisms with master-slave semantics in order to model heterogeneous systems. Generic algorithms allow for the elaboration, simulation and monitoring of such systems. A methodology to incorporate new MoCs within SystemC MDVP is defined and followed to add a SPH MoC that enables the description of fluidic network. We modeled a passive RFID reading system using several MoCs. We compare the results with measures acquired on a real physical prototype
Mollaret, Christophe. „Perception multimodale de l'homme pour l'interaction Homme-Robot“. Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30225/document.
Der volle Inhalt der QuelleThis work is about human multimodal perception for human-robot interaction (HRI). This work was financed by the RIDDLE ANR Contint project (2012-2015). This project focuses on the development of an assisting robot for the elderly who experience small losses of memory. This project aims at coping with a growing need in human care for elder people living alone. Indeed in France, the population is aging and around 33% of the estimated population will be more than 60 years old by 2060. The goal is therefore to program an interactive robot (with perceptive capabilities), which would be able to learn the relationship between the user and a set of selected objects in their shared environment. In this field, lots of problems remain in terms of : (i) shared human-environment perception, (ii) integration on a robotic platform, and (iii) the validation of some scenarii about usual objects that involve both the robot and the elderly. The aim is to see the robot answer the user's interrogations about ten objects (defined by a preliminary study) with appropriate actions. For example, the robot will indicate the position of an object by moving towards it, grapping it or giving oral indications if it is not reachable. The RIDDLE project was formed by a consortium, with Magellium, the gerontology center of Toulouse, the MINC team from the LAAS-CNRS laboratory and Aldebaran Robotics. The final demonstrations will be led on the Rom´eo platform. This thesis has been co-directed by Fr´ed´eric Lerasle and Isabelle Ferran´e, respectively from the RAP team of LAAS-CNRS and the SAMoVA team of IRIT. Along the project, in partnership with the gerontology center, a robot scenario was determined following three major steps. During the first one -the "Monitoring step"- the robot is far from the user and waits for an intention of interaction. A "Proximal interaction step" is reached when the robot interacts with the user from a close position. Finally, the last step : the "Transition" allows the robot to move to reach the two previous ones. This scenario was built in order to create a not-intrusive proactive robot. This non-intrusiveness is materialized by the "monitoring step". The proactivity is achieved by the creation of a detector of user intention, allowing the robot to understand non-verbal information about the user's will to communicate with it. The scientific contributions of this thesis include various aspects : robotic scenarii, the detector of user intention, a filtering technique based on particle swarm optimization algorithm, and finally a Baysian scheme built to improve the word error rate given distance information. This thesis is divided in four chapters. The first one is about the detector of user intention. The second chapter moves on to the filtering technique. The third chapter will focus on the proximal interaction and the employed techniques, and finally the last chapter will deal with the robotic implementations
Ahmed, Nacer Abdelaziz. „Analyse et dimensionnement de réseaux hétérogènes embarqués“. Phd thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/20115/1/AHMEDNACER_Abdelaziz.pdf.
Der volle Inhalt der QuelleAyed, Hamdi. „Analyse et optimisation des réseaux avioniques hétérogènes“. Thesis, Toulouse, INPT, 2014. http://www.theses.fr/2014INPT0113/document.
Der volle Inhalt der QuelleThe aim of my thesis is to provide a resources-efficient gateway to connect Input/Output (I/O) CAN buses to a backbone network based on AFDX technology, in modern avionics communication architectures. Currently, the Remote Data Concentrator (RDC) is the main standard for gateways in avionics; and the existing implementations do not integrate any resource management mechanism. To handle these limitations, we design an enhanced CAN-AFDX RDC integrating new functions: (i) Frame Packing (FP) allowing to reduce communication overheads with reference to the currently used "1 to 1" frame conversion strategy; (ii) Hierarchical Traffic Shaping (HTS) to reduce contention on the CAN bus. Furthermore, our proposed RDC allows the connection of multiple I/O CAN buses to AFDX while guaranteeing isolation between different criticality levels, using a software partitioning mechanism. To analyze the performance guarantees offered by our proposed RDC, we considered two metrics: the end-to-end latency and the induced AFDX bandwidth consumption. Furthermore, an optimization process was proposed to achieve an optimal configuration of our proposed RDC, i.e., minimizing the bandwidth utilization while meeting the real-time constraints of communication. Finally, the capacity of our proposed RDC to meet the emerging avionics requirements has been validated through a realistic avionics case study
Ben, Aoun Cédric. „Principes et réalisation d'un environnement de prototypage virtuel de systèmes hétérogènes composables“. Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066160/document.
Der volle Inhalt der QuelleCurrent and future microelectronics systems are more and more complex. In a aim to bridge the gap between the cyber world and the physical world we observe the emergence of multi-disciplinary systems that interact more and more with their close surrounding environment. The conception of such systems requires the knowledge of multiple scientific disciplines which tends to define them as heterogeneous systems. Designers of the upcoming digital-centric systems are lacking a common design and simulation environment able to manage all the multi-disciplinary aspects of its components of various nature, which closely interact with each other. We explore the possibilities of developing and deploying a unified SystemC-based design environment for virtual prototyping of heterogeneous systems. To overcome the challenges related to their specification and dimensioning this environment must be able to simulate a heterogeneous system as a whole, for which each component is described and solved using the most appropriate MoC. We propose a simulator prototype called SystemC MDVP which is implemented as an extension of SystemC. It follows a correct-by-construction approach, relies on a hierarchical heterogeneity representation and interaction mechanisms with master-slave semantics in order to model heterogeneous systems. Generic algorithms allow for the elaboration, simulation and monitoring of such systems. A methodology to incorporate new MoCs within SystemC MDVP is defined and followed to add a SPH MoC that enables the description of fluidic network. We modeled a passive RFID reading system using several MoCs. We compare the results with measures acquired on a real physical prototype
Mirani, Farhan Hyder. „Exploitig multipath for mobile terminals with heterogeneous multi-access“. Electronic Thesis or Diss., Paris, ENST, 2012. http://www.theses.fr/2012ENST0001.
Der volle Inhalt der QuelleThis thesis deals with a multipath solution for multi-interfaced mobile terminals that enables the use of parallel data paths to achieve higher throughput as well as transmission reliability in heterogeneous wireless networks. it proposes a transport-layer multipath solution called forward prediction scheduling (fps). fps alleviates the out-of-order data reception problem by estimating the delays incurred to data on each candidate path beforehand, and then scheduling the transmission of a data packet such that it is received in line with packets from other paths.preliminary performance evaluation of fps is carried out using ns-2's sctp-cmt model. this is then followed by fps implementation in linux kernel version of sctp (lksctp) and tests using a mobile device with heterogeneous set of wired and wireless network interfaces. the results prove the performance improvements brought by fps in face of high path delay ratios and dynamic wireless links.a cross-layer extension of fps mechanism is also proposed which contributes to accurate path delay calculations using layer-2 information in 802.11 wireless links.finally, a reliability-driven network coding multipath solution is proposed which enables a multi-interfaced host to transmit linearly encoded combinations of original data packets using its multiple paths. with the help of preliminary results, it is shown that the application of linear coding with fps mechanism significantly improves data transmission reliability as well as leads to less out-of-order reception problem
Bourge, Alban. „Changement de contexte matériel sur FPGA, entre équipements reconfigurables et hétérogènes dans un environnement de calcul distribué“. Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT068/document.
Der volle Inhalt der QuelleDynamically reconfigurable architectures offer theoretically excellent trade-off between performance and flexibility. Practically, these architectures are based on one or several processors and several reconfigurable cells. A reconfigurable cell can load, execute and unload hardware accelerators. This property enables virtualization of hardware tasks. In this context, an application can take benefit from both software flexibility and hardware performance. In current reconfigurable architectures, hardware tasks are limited to cooperative multi-tasking, since reconfiguration time and context-storing time are expensive. While reconfiguration time is architecture-dependent, the time required to store or restore the context strongly depends on applications running on hardware tasks. Reducing this context-switch time is mandatory to offer to hardware task a preemptive multi-tasking, just like software tasks. Several methods exist to perform the hardware context-switch operations in an homogeneous cell context: dedicated readback chain on reconfigurable fabrics, checkpoints, scan-chain on live context. But, nothing has been proposed in an heterogeneous fabric context (e.g. a cloud providing hardware acceleration on various kind of FPGA board).The goal of this thesis is to propose new methodologies and algorithms to enable hardware context-switch even between heterogeneous hardware targets. During the thesis, the student will have to:- Realize a bibliography on the existing hardware task preemption methods in homogeneous cell context.- Propose algorithms that enable a lightweight and generic context switch solution for hardware tasks.- Validate these algorithms by their integration in a hardware accelerator generation flow. Thus, the extended flow can generate in addition of the hardware task of an application, the dedicated hardware support for context-switch.- Propose an generation strategy (incremental, multi-target,...) suitable for heterogeneous targets. The strategy has to preserve synchronization points between targets- Prototype proof-of-concepts on the strategy on an FPGA cloud
Youssef, Marie-Josépha. „Nouvelles approches pour l’allocation des ressources dans les réseaux de communication futurs utilisant NOMA et aidés par les drones“. Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2020. http://www.theses.fr/2020IMTA0208.
Der volle Inhalt der QuelleWith a forecasted number of billions of connected devices, the Internet of Things (IoT) is driving the evolution of wireless communication networks. This exponential increase in the number of connected devices is accompanied by a proliferation of heterogeneous IoT applications, resulting in the emergence of new wireless use cases that greatly differ from conventional multimedia services. When compared to previous communication systems, next generation wireless communication systems are expected to provide very high data rates, high reliability, low latency, improvement in the quality of service (QoS) perceived by users and an increase in the number of supported users.To meet these requirements, some of the key elements future communication systems must leverage include novel spectrum access techniques such as non-orthogonal multiple access (NOMA) and uncoordinated spectrum access, self-organized networks (SON) and unmanned aerial vehicles (UAV)-aided communication networks. The main objective of this thesis is to exploit these key elements to provide novel resource allocation and net-work design solutions that aim at optimizing the use of available radio resources in next generation wireless communication networks. Different settings are considered, spanning wireless systems with heterogeneous mobile traffic requirements, uncoordinated spectrum access in SONs and UAV-aided communication systems. For each setting, a solution leveraging NOMA scheduling is proposed. The obtained results of the proposed solutions are promising, where these solutions are shown to outperform existing techniques from the literature
Hecker, Artur. „Contrôle d'accès et gestion des réseaux 4G hétérogènes“. Phd thesis, Télécom ParisTech, 2005. http://pastel.archives-ouvertes.fr/pastel-00001415.
Der volle Inhalt der QuelleSidi, Bah Aladé Habib. „Algorithmes distribués dans les réseaux hétérogènes et autonomes“. Phd thesis, Université d'Avignon, 2012. http://tel.archives-ouvertes.fr/tel-00879973.
Der volle Inhalt der QuelleWack, Maxime. „Méthode de description de réseaux locaux industriels hétérogènes“. Compiègne, 1991. http://www.theses.fr/1991COMPD419.
Der volle Inhalt der QuelleHong, Xiang. „Nouveaux catalyseurs hétérogènes chiraux pour le dédoublement cinétique hydrolytique des époxydesTERMINAUX“. Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00770302.
Der volle Inhalt der QuelleHaydar, Jamal. „Prise de décision orientée QoS dans les réseaux hétérogènes“. Paris 6, 2010. http://www.theses.fr/2010PA066184.
Der volle Inhalt der QuelleTantani, Youness. „Gestion de la relève verticale dans les réseaux mobiles hétérogènes“. Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27582/27582.pdf.
Der volle Inhalt der QuelleThe development and proliferation of wireless networks has contributed to the evolution of our daily lives. Mobile users can move between heterogeneous networks, using terminals with multiple access interfaces. Thus, the most important issue in such environment is the Always Best Connected (ABC) concept allowing the best connectivity to applications anywhere at anytime. To answer ABC requirement, various vertical handover decision strategies have been proposed using advanced tools and proven concepts. In this paper, two architectures interconnecting a UMTS network and another Wimax have been presented. Each architecture uses a protocol for mobility management, namely MIP and SIP. To evaluate the two procedures, we are given two indicators, the signaling cost and the vertical handover delay. To evaluate our scenarios, we have established a specified signaling messages flow diagram specific to each scenario, one based on the MIP and the other based on the SIP. Then, we have given expressions for each of the two indicators mentioned above that we have implemented in MATLAB. The results show that, generally, the scenario based on MIP has lower signaling cost and delay than the scenario based on SIP.
Corbellini, Giorgio. „MAC adaptatif pour les réseaux de capteurs sans fil hétérogènes“. Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00771767.
Der volle Inhalt der QuelleKassar-Ben, Jemaa Meriem. „Gestion du handover vertical dans les réseaux sans fil hétérogènes“. Paris 6, 2009. http://www.theses.fr/2009PA066742.
Der volle Inhalt der QuelleAchir, Nadjib. „Distribution de la vidéo multi-objets dans les réseaux hétérogènes“. Paris 6, 2003. http://www.theses.fr/2003PA066499.
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