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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Towards Efficient Resource Allocation for Embedded Systems

Hasler, Mattis 06 June 2023 (has links)
Das Hauptthema ist die dynamische Ressourcenverwaltung in eingebetteten Systemen, insbesondere die Verwaltung von Rechenzeit und Netzwerkverkehr auf einem MPSoC. Die Idee besteht darin, eine Pipeline für die Verarbeitung von Mobiler Kommunikation auf dem Chip dynamisch zu schedulen, um die Effizienz der Hardwareressourcen zu verbessern, ohne den Ressourcenverbrauch des dynamischen Schedulings dramatisch zu erhöhen. Sowohl Software- als auch Hardwaremodule werden auf Hotspots im Ressourcenverbrauch untersucht und optimiert, um diese zu entfernen. Da Applikationen im Bereich der Signalverarbeitung normalerweise mit Hilfe von SDF-Diagrammen beschrieben werden können, wird deren dynamisches Scheduling optimiert, um den Ressourcenverbrauch gegenüber dem üblicherweise verwendeten statischen Scheduling zu verbessern. Es wird ein hybrider dynamischer Scheduler vorgestellt, der die Vorteile von Processing-Networks und der Planung von Task-Graphen kombiniert. Es ermöglicht dem Scheduler, ein Gleichgewicht zwischen der Parallelisierung der Berechnung und der Zunahme des dynamischen Scheduling-Aufands optimal abzuwägen. Der resultierende dynamisch erstellte Schedule reduziert den Ressourcenverbrauch um etwa 50%, wobei die Laufzeit im Vergleich zu einem statischen Schedule nur um 20% erhöht wird. Zusätzlich wird ein verteilter dynamischer SDF-Scheduler vorgeschlagen, der das Scheduling in verschiedene Teile zerlegt, die dann zu einer Pipeline verbunden werden, um mehrere parallele Prozessoren einzubeziehen. Jeder Scheduling-Teil wird zu einem Cluster mit Load-Balancing erweitert, um die Anzahl der parallel laufenden Scheduling-Jobs weiter zu erhöhen. Auf diese Weise wird dem vorhandene Engpass bei dem dynamischen Scheduling eines zentralisierten Schedulers entgegengewirkt, sodass 7x mehr Prozessoren mit dem Pipelined-Clustered-Dynamic-Scheduler für eine typische Signalverarbeitungsanwendung verwendet werden können. Das neue dynamische Scheduling-System setzt das Vorhandensein von drei verschiedenen Kommunikationsmodi zwischen den Verarbeitungskernen voraus. Bei der Emulation auf Basis des häufig verwendeten RDMA-Protokolls treten Leistungsprobleme auf. Sehr gut kann RDMA für einmalige Punkt-zu-Punkt-Datenübertragungen verwendet werden, wie sie bei der Ausführung von Task-Graphen verwendet werden. Process-Networks verwenden normalerweise Datenströme mit hohem Volumen und hoher Bandbreite. Es wird eine FIFO-basierte Kommunikationslösung vorgestellt, die einen zyklischen Puffer sowohl im Sender als auch im Empfänger implementiert, um diesen Bedarf zu decken. Die Pufferbehandlung und die Datenübertragung zwischen ihnen erfolgen ausschließlich in Hardware, um den Software-Overhead aus der Anwendung zu entfernen. Die Implementierung verbessert die Zugriffsverwaltung mehrerer Nutzer auf flächen-effiziente Single-Port Speichermodule. Es werden 0,8 der theoretisch möglichen Bandbreite, die normalerweise nur mit flächenmäßig teureren Dual-Port-Speichern erreicht wird. Der dritte Kommunikationsmodus definiert eine einfache Message-Passing-Implementierung, die ohne einen Verbindungszustand auskommt. Dieser Modus wird für eine effiziente prozessübergreifende Kommunikation des verteilten Scheduling-Systems und der engen Ansteuerung der restlichen Prozessoren benötigt. Eine Flusskontrolle in Hardware stellt sicher, dass eine große Anzahl von Sendern Nachrichten an denselben Empfänger senden kann. Dabei wird garantiert, dass alle Nachrichten korrekt empfangen werden, ohne dass eine Verbindung hergestellt werden muss und die Nachrichtenlaufzeit gering bleibt. Die Arbeit konzentriert sich auf die Optimierung des Codesigns von Hardware und Software, um die kompromisslose Ressourceneffizienz der dynamischen SDF-Graphen-Planung zu erhöhen. Besonderes Augenmerk wird auf die Abhängigkeiten zwischen den Ebenen eines verteilten Scheduling-Systems gelegt, das auf der Verfügbarkeit spezifischer hardwarebeschleunigter Kommunikationsmethoden beruht.:1 Introduction 1.1 Motivation 1.2 The Multiprocessor System on Chip Architecture 1.3 Concrete MPSoC Architecture 1.4 Representing LTE/5G baseband processing as Static Data Flow 1.5 Compuation Stack 1.6 Performance Hotspots Addressed 1.7 State of the Art 1.8 Overview of the Work 2 Hybrid SDF Execution 2.1 Addressed Performance Hotspot 2.2 State of the Art 2.3 Static Data Flow Graphs 2.4 Runtime Environment 2.5 Overhead of Deloying Tasks to a MPSoC 2.6 Interpretation of SDF Graphs as Task Graphs 2.7 Interpreting SDF Graphs as Process Networks 2.8 Hybrid Interpretation 2.9 Graph Topology Considerations 2.10 Theoretic Impact of Hybrid Interpretation 2.11 Simulating Hybrid Execution 2.12 Pipeline SDF Graph Example 2.13 Random SDF Graphs 2.14 LTE-like SDF Graph 2.15 Key Lernings 3 Distribution of Management 3.1 Addressed Performance Hotspot 3.2 State of the Art 3.3 Revising Deployment Overhead 3.4 Distribution of Overhead 3.5 Impact of Management Distribution to Resource Utilization 3.6 Reconfigurability 3.7 Key Lernings 4 Sliced FIFO Hardware 4.1 Addressed Performance Hotspot 4.2 State of the Art 4.3 System Environment 4.4 Sliced Windowed FIFO buffer 4.5 Single FIFO Evaluation 4.6 Multiple FIFO Evalutaion 4.7 Hardware Implementation 4.8 Key Lernings 5 Message Passing Hardware 5.1 Addressed Performance Hotspot 5.2 State of the Art 5.3 Message Passing Regarded as Queueing 5.4 A Remote Direct Memory Access Based Implementation 5.5 Hardware Implementation Concept 5.6 Evalutation of Performance 5.7 Key Lernings 6 Summary / The main topic is the dynamic resource allocation in embedded systems, especially the allocation of computing time and network traffic on an multi processor system on chip (MPSoC). The idea is to dynamically schedule a mobile communication signal processing pipeline on the chip to improve hardware resource efficiency while not dramatically improve resource consumption because of dynamic scheduling overhead. Both software and hardware modules are examined for resource consumption hotspots and optimized to remove them. Since signal processing can usually be described with the help of static data flow (SDF) graphs, the dynamic handling of those is optimized to improve resource consumption over the commonly used static scheduling approach. A hybrid dynamic scheduler is presented that combines benefits from both processing networks and task graph scheduling. It allows the scheduler to optimally balance parallelization of computation and addition of dynamic scheduling overhead. The resulting dynamically created schedule reduces resource consumption by about 50%, with a runtime increase of only 20% compared to a static schedule. Additionally, a distributed dynamic SDF scheduler is proposed that splits the scheduling into different parts, which are then connected to a scheduling pipeli ne to incorporate multiple parallel working processors. Each scheduling stage is reworked into a load-balanced cluster to increase the number of parallel scheduling jobs further. This way, the still existing dynamic scheduling bottleneck of a centralized scheduler is widened, allowing handling 7x more processors with the pipelined, clustered dynamic scheduler for a typical signal processing application. The presented dynamic scheduling system assumes the presence of three different communication modes between the processing cores. When emulated on top of the commonly used remote direct memory access (RDMA) protocol, performance issues are encountered. Firstly, RDMA can neatly be used for single-shot point-to-point data transfers, like used in task graph scheduling. Process networks usually make use of high-volume and high-bandwidth data streams. A first in first out (FIFO) communication solution is presented that implements a cyclic buffer on both sender and receiver to serve this need. The buffer handling and data transfer between them are done purely in hardware to remove software overhead from the application. The implementation improves the multi-user access to area-efficient single port on-chip memory modules. It achieves 0.8 of the theoretically possible bandwidth, usually only achieved with area expensive dual-port memories. The third communication mode defines a lightweight message passing (MP) implementation that is truly connectionless. It is needed for efficient inter-process communication of the distributed and clustered scheduling system and the worker processing units’ tight coupling. A hardware flow control assures that an arbitrary number of senders can spontaneously start sending messages to the same receiver. Yet, all messages are guaranteed to be correctly received while eliminating the need for connection establishment and keeping a low message delay. The work focuses on the hardware-software codesign optimization to increase the uncompromised resource efficiency of dynamic SDF graph scheduling. Special attention is paid to the inter-level dependencies in developing a distributed scheduling system, which relies on the availability of specific hardwareaccelerated communication methods.:1 Introduction 1.1 Motivation 1.2 The Multiprocessor System on Chip Architecture 1.3 Concrete MPSoC Architecture 1.4 Representing LTE/5G baseband processing as Static Data Flow 1.5 Compuation Stack 1.6 Performance Hotspots Addressed 1.7 State of the Art 1.8 Overview of the Work 2 Hybrid SDF Execution 2.1 Addressed Performance Hotspot 2.2 State of the Art 2.3 Static Data Flow Graphs 2.4 Runtime Environment 2.5 Overhead of Deloying Tasks to a MPSoC 2.6 Interpretation of SDF Graphs as Task Graphs 2.7 Interpreting SDF Graphs as Process Networks 2.8 Hybrid Interpretation 2.9 Graph Topology Considerations 2.10 Theoretic Impact of Hybrid Interpretation 2.11 Simulating Hybrid Execution 2.12 Pipeline SDF Graph Example 2.13 Random SDF Graphs 2.14 LTE-like SDF Graph 2.15 Key Lernings 3 Distribution of Management 3.1 Addressed Performance Hotspot 3.2 State of the Art 3.3 Revising Deployment Overhead 3.4 Distribution of Overhead 3.5 Impact of Management Distribution to Resource Utilization 3.6 Reconfigurability 3.7 Key Lernings 4 Sliced FIFO Hardware 4.1 Addressed Performance Hotspot 4.2 State of the Art 4.3 System Environment 4.4 Sliced Windowed FIFO buffer 4.5 Single FIFO Evaluation 4.6 Multiple FIFO Evalutaion 4.7 Hardware Implementation 4.8 Key Lernings 5 Message Passing Hardware 5.1 Addressed Performance Hotspot 5.2 State of the Art 5.3 Message Passing Regarded as Queueing 5.4 A Remote Direct Memory Access Based Implementation 5.5 Hardware Implementation Concept 5.6 Evalutation of Performance 5.7 Key Lernings 6 Summary
32

[en] DESIGN AND SOCIAL INNOVATION: SOCIAL TECHNOLOGY BASED ON METHODOLOGICAL APPROACHES TO DESIGN / [pt] DESIGN E INOVAÇÃO SOCIAL: TECNOLOGIA SOCIAL A PARTIR DE ABORDAGENS METODOLÓGICAS DO DESIGN

LUIZ CLAUDIO LAGARES IZIDIO 11 March 2021 (has links)
[pt] A presente dissertação trata do design como estratégia de inovação social, através do entendimento do uso de suas metodologias para o desenvolvimento de tecnologias sociais. Investiga como metodologias de design, usadas na prática de projetos/ grupos produtivos/ empreendimentos solidários com produção artesanal se tornam tecnologias sociais, e podem ser reaplicadas. Para tanto, foram realizadas revisões bibliográfica sobre conceitos de inovação social, tecnologia apropriada, prática colaborativa, tecnologia social, sustentabilidade e codesign, dentre outros; um levantamento dos princípios e parâmetros de formação de tecnologias sociais; um estudo de casos múltiplos com análise de quatro grupos que trabalham a relação do design com o artesanato, incluindo como instrumentos de pesquisa questionário online e entrevistas, mapeamento de iniciativas, análise dos dados com cruzamento de informações. Uma discussão acerca dos modelos metodológicos adotados pelas iniciativas dos quatro grupos se segue, e quadros comparativos são elaborados no intuito de dar visibilidade aos achados da pesquisa. O estudo verificou que no processo de inovação social o design contribui com suas metodologias, dentre outras coisas, para a geração de tecnologias sociais visando uma melhor qualidade de vida das pessoas, desenvolvimento local e transformação social. / [en] The present dissertation deals with design as a strategy of social innovation, through the understanding of the use of its methodologies for the development of social technologies. It investigates how design methodologies, used in the practice of projects / productive groups / solidary enterprises with handcraft production become social technologies, and can be reapplied. For that, a bibliographic review was carried out on concepts such as social innovation, appropriate technology, collaborative practice, social technology, sustainability and codesign, among others; a survey of principles and parameters of social technology formation was done; and a multiple case studies was conducted, with analysis of four groups working the relationship between design and the handcraft, including research instruments as online questionnaire and interviews, mapping initiatives, and data analysis with cross-information. Then a discussion about the methodological models adopted by the initiatives of the four studied groups follows, and comparative tables are elaborated in order to give visibility to the findings of the research. The study found that in the process of social innovation, design contributes with its methodologies, among other things, to the generation of social technologies aimed at a better quality of life for people, local development and social transformation.
33

Intégration d'un système d'exploitation dans le flot de développement logiciel/matériel

Julien, Marc January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
34

Codesigning a Mobile Interface for Travel Planning on Digital Maps

Yu-Shen Ho (7040675) 16 August 2019 (has links)
Nowadays, increasing numbers of people do travel research on their smartphones. More precisely, digital maps provide locational information, which is important during the planning process. However, smartphones are restricted by their small screen size, resulting in fragmented information delivery; also, the design of digital maps lacks features. The aims of this study are to investigate users’ travel-planning behavior on smartphones, identify the pain points and missing contexts when using digital maps on smartphones, and provide design guidelines for future digital map design. The study was done by conducting a travel-planning activity and a codesign workshop to bring users into the design process, promote in-depth discussion, and explore a new design possibility for digital maps with users. The results showed that people’s goals when planning travel include reducing their workload, improving effectiveness, and ensuring flexibility. People use digital maps to support not only information searching but also information compiling, including saving locations and routes. In addition, several difficulties have been pointed out: cross-platform planning, information hierarchy, and retrieval on digital maps.
35

Co-Design of Antenna and LNA for 1.7 - 2.7 GHz

Jacob, Kane, Gudey, Bala Bhaskar January 2012 (has links)
In a radio frequency (RF) system, the front-end of a radio receiver consists of an active antenna arrangement with a conducting mode antenna along with an active circuit. This arrangement helps avoid losses and SNR degradation due to the use of a coaxial cable. The active circuit is essentially an impedance matching network and a low noise amplification (LNA) stage. The input impedance of the antenna is always different from the source impedance required to be presented at the LNA input for maximum power gain and this gives rise to undesired reflections at the antenna-LNA junction. This necessitates a matching network that provides the impedance matching between the antenna and the LNA at a central frequency (CF). From the Friis formula it is seen that the total noise figure (NF) of the system is dependent on the noise figure and gain of the first stage. So, by having an LNA that provides a high gain (typically >15 dB) which inserts minimum possible noise (desirably < 1 dB), the overall noise figure of the system can be maintained low. The LNA amplifies the signal to a suitable power level that will enable the subsequent demodulation and decoding stages to efficiently recover the original signal. The antenna and the LNA can be matched with each other in two possible ways. The first approach is the traditional method followed in RF engineering where in both the antenna and LNA are matched to 50 W terminations and connected to each other. In this classical method, the antenna and LNA are matched to 50 W at the CF and does not take into account the matching at other frequencies in the operation range. The second approach employs a co-design method to match the antenna and LNA without a matching network or with minimum possible components for matching. This is accomplished by varying one or more parameters of either the antenna or LNA to control the impedances and ultimately achieve a matching over a substantial range of frequencies instead at the CF alone. The co-design method is shown to provide higher gain and a lower NF with reduced number of components, cost and size as compared to the classical method. The thesis work presented here is a study, design and manufacturing of an antenna-LNA module for a wide frequency range of 1.7 GHz – 2.7 GHz to explore the gain and NF improvements in the co-design approach. Planar micro strip patch antennas and GaAs E-pHEMT transistor based LNA’s are designed and the matching and co-design are simulated to test the gain and NF improvements. Furthermore, fully functional prototypes are developed with Roger R04360 substrate and the results from simulations and actual measurements are compared and discussed.
36

A inclusão do usuário no processo de codesign como forma de aprimorar o projeto de informação

Brunelli, Carmela Vieira 08 April 2016 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-09-15T15:30:48Z No. of bitstreams: 1 Carmela Vieira Brunelli_.pdf: 9931445 bytes, checksum: 9a5e2f7bb929a9c43f246fbac7f8dc71 (MD5) / Made available in DSpace on 2016-09-15T15:30:48Z (GMT). No. of bitstreams: 1 Carmela Vieira Brunelli_.pdf: 9931445 bytes, checksum: 9a5e2f7bb929a9c43f246fbac7f8dc71 (MD5) Previous issue date: 2016-04-08 / Nenhuma / Neste estudo investigou-se o processo de projeto de informação através da ferramenta infográfico, a fim de entender de que modo a inclusão e a própria expressão do usuário no processo podem otimizá-lo. Explorou-se a forma com que o designer e o usuário da informação podem, através do codesign, projetar um infográfico que elimine, satisfatoriamente, lacunas na compreensão do usuário sobre um conteúdo técnico. Utilizando-se a metodologia de pesquisa-ação, que envolveu designers, usuários e outros, realizou-se um Workshop e Entrevistas em Profundidade, que serviram de campo para desenvolver um protótipo de infográfico. A partir dos resultados obtidos nesses ambientes, discutiram-se os principais achados em relação à inserção do usuário e ao aprimoramento da metodologia de projeto abordada. Nessa discussão analisou-se: o papel ativo do usuário no processo; o papel do designer, como tradutor de suas impressões sobre o usuário; e o papel do infográfico como ferramenta de projeto de informação. A avaliação dos atores em relação ao processo permitiu identificar pontos positivos agregados pelo codesign ao projeto, entre os quais a capacidade do usuário de criar atalhos e otimizar processos. Também foram abordadas as competências dos designers e os aspectos estruturais do infográfico, com o objetivo de justificar a perspectiva cocriativa para otimizar a informação. / The present study investigates the information design process through infographics, in order to understand how user involvement and expression can optimize the process. We examine how, through codesign, information designers and users can design an infographic that successfully eliminates gaps in user understanding of technical content. Using an action research methodology involving designers, users and authors in a cocreative approach, a workshop and in-depth interviews were conducted to serve as an arena for the development of a prototype infographic. Based on the results obtained in these settings, we discuss the main findings regarding user insertion and improvement of the design methodology by analyzing the active role of users in the infographic design process, the role of designers in conveying their impressions about users, and the role of the infographic as an information design tool. This assessment identifies the positive contribution of codesign to the design as a whole, such as the user’s ability to create shortcuts and optimize processes. We also address the skills of designers and structural aspects of the infographic in order to justify the cocreative approach as a means of optimizing information.
37

A hardware/software codesign for the chemical reactivity of BRAMS / Um coprojeto de hardware/software para a reatividade química do BRAMS

Souza Junior, Carlos Alberto Oliveira de 05 June 2017 (has links)
Several critical human activities depend on the weather forecasting. Some of them are transportation, health, work, safety, and agriculture. Such activities require computational solutions for weather forecasting through numerical models. These numerical models must be accurate and allow the computers to process them quickly. In this project, we aim at migrating a small part of the software of the weather forecasting model of Brazil, BRAMS Brazilian developments on the Regional Atmospheric Modelling System to a heterogeneous system composed of Xeon (Intel) processors coupled to a reprogrammable circuit (FPGA) via PCIe bus. According to the studies in the literature, the chemical equation from the mass continuity equation is the most computationally demanding part. This term calculates several linear systems Ax = b. Thus, we implemented such equations in hardware and provided a portable and highly parallel design in OpenCL language. The OpenCL framework also allowed us to couple our circuit to BRAMS legacy code in Fortran90. Although the development tools present several problems, the designed solution has shown to be viable with the exploration of parallel techniques. However, the performance was below of what we expected. / Várias atividades humanas dependem da previsão do tempo. Algumas delas são transporte, saúde, trabalho, segurança e agricultura. Tais atividades exigem solucões computacionais para previsão do tempo através de modelos numéricos. Estes modelos numéricos devem ser precisos e ágeis para serem processados no computador.Este projeto visa portar uma pequena parte do software do modelo de previsão de tempo do Brasil, o BRAMSBrazilian developments on the Regional Atmospheric Modelling Systempara uma arquitetura heterogênea composta por processadores Xeon (Intel) acoplados a um circuito reprogramável em FPGA via barramento PCIe. De acordo com os estudos, o termo da química da equação de continuidade da massa é o termo mais caro computacionalmente. Este termo calcula várias equações lineares do tipo Ax = b. Deste modo, este trabalho implementou estas equações em hardware, provendo um ´codigo portável e paralelo na linguagem OpenCL. O framework OpenCL também nos permitiu acoplar o código legado do BRAMS em Fortran90 junto com o hardware desenvolvido. Embora as ferramentas de desenvolvimento tenham apresentado vários problemas, a solução implementada mostrou-se viável com a exploração de técnicas de paralelismo. Entretando sua perfomance ficou muito aquém do desejado.
38

Exploration de l'Espace de Conception des Architectures Reconfigurables

Bossuet, Lilian 10 September 2004 (has links) (PDF)
Ce mémoire présente une méthode d'exploration de l'espace architectural de conception afin de converger rapidement vers la définition d'une architecture reconfigurable efficace pour une application donnée.<br /><br />Cette méthode intervient très tôt dans le flot de conception, ainsi dès les premières phases de spécification de l'application, les concepteurs peuvent définir une architecture adaptée pour leurs applications. La méthode d'exploration s'appuie principalement sur l'estimation de la répartition des communications dans l'architecture ainsi que sur le taux d'utilisation des ressources de l'architecture. Ces métriques permettent en effet d'orienter le processus d'exploration afin de minimiser la consommation de puissance de l'architecture puisque cette dernière est directement corrélée à ces deux métriques.<br /><br />Les résultats obtenus montrent que notre méthode permet de converger rapidement vers une architecture efficace en ce qui concerne la consommation de puissance.
39

Architecture reseau sans fil pour de la téléopération long distance d'un systeme embarqué

Khan, Zeashan Hameed 30 November 2010 (has links) (PDF)
La téléopération en réseau est une thématique émergente, où un humain (le maître) communique avec un esclave commandé à distance à travers un réseau de communication, pour l'échange des données de commande et de mesure. Pour la téléopération longue distance, ces informations traversent divers réseaux hétérogènes ou hybrides interconnectés ensemble. Nous traitons également le cas où un segment sera sans fil, ce qui permet d'envisager que l'esclave soit mobile (véhicule télé-opéré par exemple). Une étude indépendante des aspects commande et des aspects réseau entraîne l'atteinte d'objectifs locaux, qui peuvent le cas échéant être ensuite fortement dégradés après l'intégration des deux aspects. L'utilisation de réseaux partagés, comme internet, en lieu et place d'une liaison dédiée (point à point, liaison virtuelle) est également un défi, en particulier dans le cas de la longue distance. Les mécanismes de qualité de service (QdS) d'un réseau, en particulier du réseau hétérogène, doivent pouvoir être traités par les autres réseaux ; ces points sont assez souvent traités avec un point de vue d'applications multimedia, plus rarement avec le point de vue de la téléopération critique. L'approche de téléopération en réseau peut profiter de ces mécanismes de qualité de service en utilisant des priorités ou des réservations de bandes passantes en fonction des critères de commande et de transparence. Cela peut entraîner une adaptation des ressources réseau en fonction des besoins des objectifs de téléopération afin de transporter l'information en satisfaisant les besoins bout en bout de l'application, cette notion devant être précisée. Lorsqu'on considère la QdS avec un point de vue réseau, elle consiste principalement à la gestion de flux de communication, en prenant en compte des paramètres de besoin et d'ordonnancement. Si l'on prend en compte le point de vue de la téléopération, la QdS entraîne des conséquences sur la qualité de commande (QdC) ce qui inclut la stabilité, la transparence et la téléprésence. De plus, l'interface humaine peut également avoir des besoins spécifiques en termes de téléprésence, ce qui peut entraîner des conséquences sur la répartition de la charge du réseau. Afin d'intégrer les deux approches de QdS et de QdC pour apporter une meilleure réponse au problème posé, nous proposons une approche de coconception avec d'une part une adaptation de la QdS aux besoins de la Qdc (qualité de la transparence) et d'autre part une adaptation de la Qdc (par exemple dégradation de la qualité du flux vidéo) à la disponibilité du réseau. Nous avons considéré deux cas de figures. Dans un premier temps, sans tenir compte des mécanismes de QdS du réseau (approche dite du meilleur effort ou best effort) et par l'adaptation au mieux de l'application, pour répondre aux besoins de la téléopération. La seconde approche considère un réseau orienté QdS entre le maître et l'esclave, où différentes priorités peuvent être attribuées aux flux nécessaires à la téléopération, en fonction des contextes. L'approche proposée est finalement mise en oeuvre sur NeCS-Car, la voiture téléopérée disponible au Laboratoire.
40

Architecture Reconfigurable pour un Equipement Radio Multistandard

Alaus, Laurent 28 May 2010 (has links) (PDF)
Dans un contexte de multiplication des normes de télécommunications aux spécifications distinctes, nos travaux de recherche définissent une architecture reconfigurable pour des terminaux radio multistandard. Nous proposons ainsi une nouvelle méthode de paramétrisation intitulée "la Technique des Opérateurs Communs" afin d'accéder à la combinaison " reconfiguration temps réel/généricité du terminal". Cette technique est une méthodologie de conception et d'exécution qui vise à développer un ensemble limité d'"Opérateurs Communs" (OC), génériques, reconfigurables par simple téléchargement de paramètres, indépendants de la cible technologique d'implémentation et qui constituent les éléments de base de notre terminal multistandard. Afin d'exécuter l'ensemble du terminal multistandard, trois familles d'OC sont proposées (LFSR, FFT/VITERBI, CORDIC). Une méthodologie de gestion des OC est également présentée et une étude de di_érents cas d'implémentations est menée, permettant d'atteindre des gains en complexité jusqu'à 40% de la complexité matérielle sur une cible FPGA dans le cas d'un terminal tri-standard (IEEE 802.11, IEEE802.16 et 3GPP LTE).

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