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Essais sur la "smart customization" : Vers une meilleure compréhension de la perspective client relative aux offres de smart customization / Essays on smart customization : Towards a better understanding of the customer´s perspective on smart customization offersBenade, Morgane 09 February 2018 (has links)
Au cours de la dernière décennie, les technologies de l'information et de la communication intégrées aux produits de consommation ont considérablement modifié la nature de leurs usages. Réactives, les entreprises se sont emparées de ces nouvelles technologies et proposent aux consommateurs de customiser leurs produits quotidiens après achat. J’ai intitulé cette approche "Smart Customization", dans ma thèse. L´idée étant que, pour qu'une telle customisation "intelligente" ait lieu, il faut intégrer directement des boîtes à outils intelligentes (ou smart UTCD) dans nos produits de consommation. Ces boites à outils intelligentes sont ensuite destinées à guider les consommateurs dans le procédé de customisation de leurs objets. Actuellement, il n’y a pas véritablement de recherche académique alors que, au contraire, la presse industrielle évoque la smart customization comme une opportunité à exploiter. Il semble pourtant essentiel, d'identifier les facteurs de succès de ces nouvelles offres de customisation, notamment, en adoptant le point de vue du consommateur sur l´élément principal Smart UTCD. C´est ce qui a déterminé l´objectif de ma thèse. Via une étude d´acceptante technologique dans le papier 1, un choice-based conjoint analysis dans l’article 2 et une exploration des mécanismes de co-conception qui ont lieu entre le consommateur et l´outil de conception « smart UTCD », je participe à la recherche sur la smart customisation. / In the last decade, our products have been more and more equipped with information and communication technology (ICT), which has modified the nature of their applications greatly. Notably, firms find finally a mean to empower customers to customize their products after purchase. One talks about “Smart Customization”. For such “smart” customization to happen, the idea is to embed directly smart user toolkits for co-design (smart UTCD) into our consumer products. That said, while in the business press, they largely view smart customization as an opportunity to be tapped, in contrast, research is hardly focused on it. Notably, it appears essential to identify factors of customer - based success of such novel customization offers. Thereby, in paper I, I adapt and test a technology acceptance model to smart UTCD. In paper II, I realize a choice based conjoint analysis on smart UTCD. In article III, I expose a theoretical framework for use generation and apply it one the two existing types of smart UTCD. With my findings, I contribute to theory by adding to our limited understanding of the smart UTCD acceptance, providing in-depth knowledge on the customer´s choice process on the smart UTCD´ design features and by opening the black box on the co-design mechanisms that occur between customers - smart UTCD. Additionally, the findings of my three article that compose my dissertation permit firms to be provided with some measures on how to design smart customization offers that fit better the target customers.
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Design estratégico e comunidades artesanais : co-design para transformação socialFerretti, Fernanda Seidl 25 March 2015 (has links)
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Previous issue date: 2015-03-25 / Nenhuma / As intervenções de designers que, como consultores, interagem com comunidades de artesãos, para qualificar a produção artesanal e reposicioná-la no mercado consumidor, são populares no Brasil - devido ao seu potencial de gerar desenvolvimento econômico e social para tais comunidades. Investiga-se tais interações a partir da perspectiva do design estratégico, visando a geração de valor através de processos que envolvem múltiplos atores na elaboração de soluções. Objetiva-se a proposição de caminhos estratégicos para a qualificação das consultorias de designers nas comunidades artesanais, visando à promoção de processos de co-design que contribuam para a maior autonomia das comunidades em relação às instituições que fomentam tais intervenções. A partir de uma investigação exploratória, são realizados estudos de caso com três grupos produtores de artesanato que contaram com a presença de designers para o desenvolvimento de seus produtos. Analisa-se a trajetória e processos de criação de artefatos destes grupos, e descreve-se um ambiente projetual em que a estrutura organizacional e as relações interpessoais influenciam a atuação dos designers e a continuidade do projeto, e a introjeção das competências dos consultores, e o fortalecimento da rede de valor dos grupos favorecem a autonomia dos artesãos. Sintetizam-se quatro proposições centrais: 1) a atuação do designer como um agente de capacitação do grupo na cultura do design; 2) a criação de um espaço de co-design condutivo a uma experiência imersiva, favorecendo simultaneamente as relações interpessoais e a projetação colaborativa; 3) a facilitação do processo de co-design e da capacitação dos artesãos, a partir de instrumentos que combinam pesquisas metaprojetuais e o desenvolvimento das relações entre os participantes; 4) o fortalecimento da rede de valor dos grupos através de colaborações horizontais intergrupais. / The interventions of designers who, as consultants, interact with communities of artisans to qualify handicraft production and reposition it in the consumer market, are popular in Brazil - because of their potential to generate economic and social development for such communities. These interactions are investigated here through a strategic design's perspective, aiming at value creation through processes that involve multiple actors in the development of solutions. The objective of this research is to propose strategic paths for the qualification of design consultancies for handicraft communities, aiming to promote co-design processes that contribute to the community's greater autonomy in relation to the institutions that promote these interventions. As part of an exploratory investigation, three case studies are conducted, involving communities of artisans where designers helped to develop artifacts. The development paths and the artifact creation process of these groups are analyzed, leading to the description of a designing environment where the organizational structure and the relationships between participants have an influence on the designers work and the continuity of the project; and the introjection of the consultant's skills, and the strengthening of the community's value network contribute towards the artisan's autonomy. Four central propositions are therefore defined: 1) the role of the designer as a qualification agent in design culture; 2) the creation of a co-design space which conducts to an immersive experience while promoting interpersonal relationships and collaborative design; 3) the facilitation of the co-creation process and qualification of artisans through instruments that combine research on a metadesign level and the development of interpersonal relations; 4) the strengthening of the groups value network through horizontal intergroup collaborations.
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Support des communications dans des architectures multicœurs par l’intermédiaire de mécanismes matériels et d’interfaces de programmation standardisées / Communication support in multi-core architectures through hardware mechanisms and standardized programming interfacesRosa, Thiago Raupp da 08 April 2016 (has links)
L’évolution des contraintes applicatives imposent des améliorations continues sur les performances et l’efficacité énergétique des systèmes embarqués. Pour répondre à ces contraintes, les plateformes « SoC » actuelles s’appuient sur la multiplication des cœurs de calcul, tout en ajoutant des accélérateurs matériels dédiés pour gérer des tâches spécifiques. Dans ce contexte, développer des applications embarquées devient un défi complexe, en effet la charge de travail des applications continue à croître alors que les technologies logicielles n’évoluent pas aussi vite que les architectures matérielles, laissant un écart dans la conception complète du système. De fait, la complexité accrue de programmation peut être associée à l’absence de standards logiciels qui prennent en charge l’hétérogénéité des architectures, menant souvent à des solutions ad hoc. A l’opposé, l’utilisation d’une solution logicielle standardisée pour les systèmes embarqués peut induire des surcoûts importants concernant les performances et l’occupation de la mémoire si elle n’est pas adaptée à l’architecture. Par conséquent, le travail de cette thèse se concentre sur la réduction de cet écart en mettant en œuvre des mécanismes matériels dont la conception prend en compte une interface de programmation standard pour systèmes embarqués. Les principaux objectifs sont ainsi d’accroître la programmabilité par la mise en œuvre d’une interface de programmation : MCAPI, et de diminuer la charge logiciel des cœurs grâce à l’utilisation des mécanismes matériels développés.Les contributions de la thèse comprennent la mise en œuvre de MCAPI pour une plate-forme multicœur générique et des mécanismes matériels pour améliorer la performance globale de la configuration de la communication et des transferts de données. Il est démontré que les mécanismes peuvent être pris en charge par les interfaces logicielles sans augmenter leur complexité. En outre, les résultats de performance obtenus en utilisant un modèle SystemC/TLM de l’architecture multicœurs de référence montrent que les mécanismes proposés apportent des gains significatifs en termes de latence, débit, trafic réseau, temps de charge processeur et temps de communication sur des cas d’étude et des applications complètes. / The application constraints driving the design of embedded systems are constantly demanding higher performance and power efficiency. To meet these constraints, current SoC platforms rely on replicating several processing cores while adding dedicated hardware accelerators to handle specific tasks. However, developing embedded applications is becoming a key challenge, since applications workload will continue to grow and the software technologies are not evolving as fast as hardware architectures, leaving a gap in the full system design. Indeed, the increased programming complexity can be associated to the lack of software standards that supports heterogeneity, frequently leading to custom solutions. On the other hand, implementing a standard software solution for embedded systems might induce significant performance and memory usage overheads. Therefore, this Thesis focus on decreasing this gap by implementing hardware mechanisms in co-design with a standard programming interface for embedded systems. The main objectives are to increase programmability through the implementation of a standardized communication application programming interface (MCAPI), and decrease the overheads imposed by the software implementation through the use of the developed hardware mechanisms.The contributions of the Thesis comprise the implementation of MCAPI for a generic multi-core platform and dedicated hardware mechanisms to improve communication connection phase and overall performance of data transfer phase. It is demonstrated that the proposed mechanisms can be exploited by the software implementation without increasing software complexity. Furthermore, performance estimations obtained using a SystemC/TLM simulation model for the reference multi-core architecture show that the proposed mechanisms provide significant gains in terms of latency (up to 97%), throughput (40x increase) and network traffic (up to 68%) while reducing processor workload for both characterization test-cases and real application benchmarks.
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O usuário e o processo de projeto: co-design em edifícios de saúde / User and design process: co-design in healthcare buildingsMichele Caroline Bueno Ferrari Caixeta 26 October 2015 (has links)
Caracterizado por grande complexidade, o projeto de edifícios de assistência à saúde precisa garantir funcionalidade e eficiência operacional à edificação, através de espaços que facilitem a realização das atividades de atenção à saúde. Isto é ainda mais proeminente em países como o Brasil, onde os serviços de atenção à saúde são deficitários, principalmente na esfera pública. Para tanto, é necessário um amplo conhecimento acerca dos usuários e dos fluxos e atividades que compõem os serviços prestados, que geralmente os arquitetos não possuem. Neste contexto, e dada a complexidade dos edifícios de assistência à saúde, o envolvimento efetivo dos usuários no processo de projeto - co-design - pode contribuir para o redesenho das atividades de atenção à saúde e assim possibilitar que os arquitetos alinhem o projeto do espaço físico com o projeto dos serviços, aumentando a oferta e a qualidade do atendimento à população. No entanto, o co-design exige grandes esforços do arquiteto, relativos à coordenação e à linguagem utilizada, entre outros desafios. O problema desta pesquisa reside, portanto, na falta de amparo e dificuldades de envolver efetivamente os usuários no processo de projeto destes edifícios, como perspectiva para trazer os conhecimentos relativos à utilização da edificação ao projeto, e assim aumentar a adequação entre edifício e uso. A pesquisa aqui proposta busca, neste sentido, uma proposição inovadora de solução através da abordagem da Design Science Research (DSR) que tem como fundamento a proposta de soluções para problemas enfrentados no mundo real. A pesquisa incluiu as etapas de entendimento do tema, com revisão bibliográfica, estudo exploratório e estudos de caso em dois projetos de edifícios de saúde com co-design; proposta de uma solução e avaliação da solução. Como solução, apresenta-se um modelo conceitual de processo de projeto com co-design para auxiliar os arquitetos na promoção desta prática em edifícios de assistência à saúde. Descreve-se ainda o processo de seleção dos representantes dos usuários para as oficinas de co-design, com as questões que devem ser consideradas pela coordenação, a preparação dos usuários, a estrutura para orientar as oficinas e as revisões de fases, indicando as entradas, os métodos e instrumentos e as saídas das oficinas, e os subprodutos para análise, os critérios de passagem e o conteúdo dos relatórios de revisão, no caso das revisões de fase. O modelo foi avaliado por quatro profissionais, que são arquitetos com experiência em projetos de edifícios de saúde e pesquisadores da área. Com base nos resultados das avaliações, o modelo foi aprimorado para sua versão final. / Characterized by high complexity, the design of a healthcare building must ensure functionality and operational efficiency to the building through spaces that support healthcare activities. This is even more prominent in countries as Brazil, where healthcare services are deficient, especially in the public sphere. Therefore, a broad knowledge on users and service flows and activities, which architects seldom have, is required. Given the complexity of healthcare buildings, the effective involvement of users in the design process - co-design - can contribute to the redesign of healthcare activities and enable architects to align the design of physical space with that of services, which increases the supply and quality of services to the population. However, co-design requires great efforts, related to coordination and design language, among other challenges, from architects. This thesis addresses the lack of support and difficulties regarding the effective engagement of users in the design process of the healthcare buildings, as a perspective to provide knowledge on the use of the building to the design and increase the adequacy of building and use. It proposes an innovative solution through the Design Science Research (DSR), based on the proposal of solutions to problems faced in the real world. The research included the stages of understanding of the theme, through a literature review, survey and case studies in two healthcare buildings designed with co-design, development of a solution and its evaluation. A conceptual model of the design process with co-design is presented to assist architects in promoting this practice in healthcare buildings. The selection process of users´ representatives is described for the co-design workshops and indicates the issues to be considered by the coordination. The study also addresses the preparation of users, a framework to guide the workshops and phase reviews, stating the inputs, methods and tools and the outputs for the workshops, the deliverables for analysis, criteria for judgment and content of revision reports, in the case of phase revisions. The model was evaluated by four professionals, who are architects and researchers skilled in healthcare building design. According to the evaluation results, the model has been enhanced to its final version.
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Contribution à l'étude de nouvelles technologies de co-packaging et de co-design appliquées à la réalisation de modules photorécepteurs pour les systèmes de télécommunications de prochaine génération / Study of new co-packaging and co-design technologies applied to photoreceiver modules for next generation telecommunication systemsAngelini, Philippe 29 June 2017 (has links)
Les travaux présentés dans cette thèse s'inscrivent dans le cadre des télécommunications optiques à haut-débit sur courtes distances. L'ère numérique dans laquelle nous vivons pousse les architectures actuelles à évoluer aussi rapidement que le besoin en débit. Les réseaux d'accès et data-centers doivent d'ores et déjà évoluer, notamment au niveau des composants et sous-systèmes chargés de détecter les signaux optiques après leur transmission : les photorécepteurs. La montée en débit à 40 Gb/s et au-delà est limitée par l'architecture actuelle des photorécepteurs dont l'interfaçage entre ses deux fonctions primaires (photodétection[PD]/amplification[TIA]) limite la bande passante. Les solutions présentées, visant à limiter la parallélisation multi-longueurs d'onde des composants et ainsi les coût de déploiement, proposent d'augmenter la rapidité des modules photorécepteurs en optimisant leur architecture. Deux axes d'optimisation sont alors proposés au niveau du photorécepteur : Une approche co-packaging ayant pour objectif de considérer les deux fonctions clés du photorécepteur comme des boîtes noires auxquelles il convient d'ajouter un circuit externe permettant d'augmenter la bande passante, et une approche co-design visant à concevoir un nouveau circuit amplificateur transimpédance (TIA) intégrant directement une fonction de pré-égalisation adaptée à la photodiode permettant de repousser la fréquence de coupure du récepteur. / This thesis falls within the scope of high-speed short-reach optical communication where the growing need in data transfer forces the current architectures to evolve as quickly. Acces network and data-center components and subsystems must follow this growth, especially on the photoreceiver side. 40 Gb{s and beyond high-speed communications are limited by the current photoreceiver architecture, which, due to the integration of both of its main functions (photodetection[PD]/amplification[TIA]), limits the maximum achievable bandwitdh. In order to reduce the amount of components and price caused by multi-architectures, photoreceivers bandwidth must be increased. Two solutions are proposed so that the photoreceiver performances can be optimized : A co-packaging approach in which both main functions of the photoreceiver are considered as black boxes to which must be added an external circuit allowing to increase the bandwidth, and a co-design approach in which a new transimpedance amplifier (TIA) is designed, integrating a pre-equalizing function based on the photodiode characteristics, allowing an enhancement of the photoreceiver bandwitdh.
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O usuário e o processo de projeto: co-design em edifícios de saúde / User and design process: co-design in healthcare buildingsCaixeta, Michele Caroline Bueno Ferrari 26 October 2015 (has links)
Caracterizado por grande complexidade, o projeto de edifícios de assistência à saúde precisa garantir funcionalidade e eficiência operacional à edificação, através de espaços que facilitem a realização das atividades de atenção à saúde. Isto é ainda mais proeminente em países como o Brasil, onde os serviços de atenção à saúde são deficitários, principalmente na esfera pública. Para tanto, é necessário um amplo conhecimento acerca dos usuários e dos fluxos e atividades que compõem os serviços prestados, que geralmente os arquitetos não possuem. Neste contexto, e dada a complexidade dos edifícios de assistência à saúde, o envolvimento efetivo dos usuários no processo de projeto - co-design - pode contribuir para o redesenho das atividades de atenção à saúde e assim possibilitar que os arquitetos alinhem o projeto do espaço físico com o projeto dos serviços, aumentando a oferta e a qualidade do atendimento à população. No entanto, o co-design exige grandes esforços do arquiteto, relativos à coordenação e à linguagem utilizada, entre outros desafios. O problema desta pesquisa reside, portanto, na falta de amparo e dificuldades de envolver efetivamente os usuários no processo de projeto destes edifícios, como perspectiva para trazer os conhecimentos relativos à utilização da edificação ao projeto, e assim aumentar a adequação entre edifício e uso. A pesquisa aqui proposta busca, neste sentido, uma proposição inovadora de solução através da abordagem da Design Science Research (DSR) que tem como fundamento a proposta de soluções para problemas enfrentados no mundo real. A pesquisa incluiu as etapas de entendimento do tema, com revisão bibliográfica, estudo exploratório e estudos de caso em dois projetos de edifícios de saúde com co-design; proposta de uma solução e avaliação da solução. Como solução, apresenta-se um modelo conceitual de processo de projeto com co-design para auxiliar os arquitetos na promoção desta prática em edifícios de assistência à saúde. Descreve-se ainda o processo de seleção dos representantes dos usuários para as oficinas de co-design, com as questões que devem ser consideradas pela coordenação, a preparação dos usuários, a estrutura para orientar as oficinas e as revisões de fases, indicando as entradas, os métodos e instrumentos e as saídas das oficinas, e os subprodutos para análise, os critérios de passagem e o conteúdo dos relatórios de revisão, no caso das revisões de fase. O modelo foi avaliado por quatro profissionais, que são arquitetos com experiência em projetos de edifícios de saúde e pesquisadores da área. Com base nos resultados das avaliações, o modelo foi aprimorado para sua versão final. / Characterized by high complexity, the design of a healthcare building must ensure functionality and operational efficiency to the building through spaces that support healthcare activities. This is even more prominent in countries as Brazil, where healthcare services are deficient, especially in the public sphere. Therefore, a broad knowledge on users and service flows and activities, which architects seldom have, is required. Given the complexity of healthcare buildings, the effective involvement of users in the design process - co-design - can contribute to the redesign of healthcare activities and enable architects to align the design of physical space with that of services, which increases the supply and quality of services to the population. However, co-design requires great efforts, related to coordination and design language, among other challenges, from architects. This thesis addresses the lack of support and difficulties regarding the effective engagement of users in the design process of the healthcare buildings, as a perspective to provide knowledge on the use of the building to the design and increase the adequacy of building and use. It proposes an innovative solution through the Design Science Research (DSR), based on the proposal of solutions to problems faced in the real world. The research included the stages of understanding of the theme, through a literature review, survey and case studies in two healthcare buildings designed with co-design, development of a solution and its evaluation. A conceptual model of the design process with co-design is presented to assist architects in promoting this practice in healthcare buildings. The selection process of users´ representatives is described for the co-design workshops and indicates the issues to be considered by the coordination. The study also addresses the preparation of users, a framework to guide the workshops and phase reviews, stating the inputs, methods and tools and the outputs for the workshops, the deliverables for analysis, criteria for judgment and content of revision reports, in the case of phase revisions. The model was evaluated by four professionals, who are architects and researchers skilled in healthcare building design. According to the evaluation results, the model has been enhanced to its final version.
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Hinder och möjlighet för förbättrad egenvård av lymfödem : En kvalitativ studie om patienternas behov och deras förbättringsförslag. / Difficulties and opportunities for improved self-care of lymphedema : A qualitative study of patients´needs and their suggestions for improvement.Bergström, Linda January 2020 (has links)
Sammanfattning Bakgrund: Lymfödem är en kronisk symtomdiagnos som kräver livslång behandling där egenvård är en viktig del. Bristande egenvård leder till försämrat lymfödem och större benägenhet för erysipelasinfektioner. Problemet är att patienterna känner sig osäkra på egenvård av lymfödem och tvivlar på dess effekt. Syfte: Förbättringsarbetets syfte var att skapa förutsättningar och bättre följsamhet till patienters egenvårdsbehandling för att bidra till bibehållet eller förbättrat stadie av lymfödem och uppleva en god hälso-relaterad livskvalitet. Syftet med studien var att beskriva patienters erfarenheter av att leva med lymfödem, erfarenhet av den lymfterapeutiska vårdtjänsten och redogöra för patienters förbättringsförslag för att förbättra egenvård. Metod: Förbättringsarbetet genomförs med inspiration från tjänstedesign och förbättringsmodellerna 5P, Nolans förbättringsmodell och PGSA.Studien utförs med tematisk analys och beskrevs utifrån delar av Kanomodellen av Noriaki Kano; bas-, uttalade- och omedvetna behov. Resultat: Patienter blir säkrare på att göra egenvård om de har en egenvårdsplan och lymfterapeuterna blir tydligare i sin kommunikation med checklistan och i samskapande med patienten. Resultat från studien visar att lymfterapeuterna behöver bättre kommunicera egenvård och anpassa informationen individuellt. Slutsatser: Genom att patienterna delar med sig av sina erfarenheter och förbättringsförslag kan vi skapa ett lärande och öppna upp för mer patientinvolvering i utvecklingsarbetet. / Summary Background: Lymphedema is a chronic diagnosis that requires lifelong treatment where self-care is an important part. Lack of self-care leads to impaired lymphedema and greater tendency for erysipelas infections. The problem is that patients feel insecure about self-care of lymphedema and doubt its effect. Purpose: The purpose of the improvement work was to create better compliance to the patients self-care treatment. The purpose of the study was to describe patients 'experiences of the lymphatic care service and living with lymphedema and also the patients' improvement suggestions for improving self-care. Method: With inspiration from service design and the improvement models 5P, Nolan's improvement model and PGSA. The study with thematic analysis method was described from parts of the Kano model by Noriaki Kano; basic-, expected- and unexpected needs. Results: Patients become more confident in self-care if they have a self-care plan and the Lymphatic Therapists become clearer in their communication by a checklist and in collaboration with the patient. Results from the study show that the lymphatic therapists need to better communicate self-care and adapt the information individually. Conclusions: By sharing patients' experiences and suggestions for improvement, we can create learning and more patient involvement in development work.
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The AIR model (Activities, Internal world, Relationships): a pragmatic framework for evaluating co-designGosling, Julie, Craven, Michael P., Dening, Tom, Coleston-Shields, Dons, Aberturas, Adriana G., Martin, Sandra G., Muñoz, Marcos, Ruiz, Guillermo B., Bueno, Yolanda, Almeida, Rosa, Català, Andreu, Diaz, Marta, Karahanoglu, Armağan, Ludden, Geke D. S., Smith, Tina, Niederer, Kristina, Lüneburg, Lisa-Marie, Tournier, Isabelle, Abrilahij, Afsaneh 18 December 2019 (has links)
A pragmatic model, AIR (Activities; Internal world; Relationships), is presented for co-design of technologies and products to support well-being of people living with dementia. This model, co-developed with people with lived experience, is aimed at including psychosocial aspects in the prototype development process. The model is then related to a form of mindful evaluation framework that can be employed during the prototype testing of co-designed solutions. The components of this evaluation framework and associated instruments are described.
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A New System Architecture for Heterogeneous Compute UnitsAsmussen, Nils 09 August 2019 (has links)
The ongoing trend to more heterogeneous systems forces us to rethink the design of systems. In this work, I study a new system design that considers heterogeneous compute units (general-purpose cores with different instruction sets, DSPs, FPGAs, fixed-function accelerators, etc.) from the beginning instead of as an afterthought. The goal is to treat all compute units (CUs) as first-class citizens, enabling (1) isolation and secure communication between all types of CUs, (2) a direct interaction of all CUs, removing the conventional CPU from the critical path, and (3) access to operating system (OS) services such as file systems and network stacks for all CUs.
To study this system design, I am using a hardware/software co-design based on two key ideas: 1) introduce a new hardware component next to each CU used by the OS as the CUs' common interface and 2) let the OS kernel control applications remotely from a different CU. The hardware component is called data transfer unit (DTU) and offers the minimal set of features to reach the stated goals: secure message passing and memory access. The OS is called M³ and runs its kernel on a dedicated CU and runs the OS services and applications on the remaining CUs. The kernel is responsible for establishing DTU-based communication channels between services and applications. After a channel has been set up, services and applications communicate directly without involving
the kernel. This approach allows to support arbitrary CUs as aforementioned first-class citizens, ranging from fixed-function accelerators to complex general-purpose cores.
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Design and Real-World Evaluation of Dependable Wireless Cyber-Physical SystemsMager, Fabian 09 August 2023 (has links)
The ongoing effort for an efficient, sustainable, and automated interaction between humans, machines, and our environment will make cyber-physical systems (CPS) an integral part of the industry and our daily lives. At their core, CPS integrate computing elements, communication networks, and physical processes that are monitored and controlled through sensors and actuators. New and innovative applications become possible by extending or replacing static and expensive cable-based communication infrastructures with wireless technology. The flexibility of wireless CPS is a key enabler for many envisioned scenarios, such as intelligent factories, smart farming, personalized healthcare systems, autonomous search and rescue, and smart cities.
High dependability, efficiency, and adaptivity requirements complement the demand for wireless and low-cost solutions in such applications. For instance, industrial and medical systems should work reliably and predictably with performance guarantees, even if parts of the system fail. Because emerging CPS will feature mobile and battery-driven devices that can execute various tasks, the systems must also quickly adapt to frequently changing conditions. Moreover, as applications become ever more sophisticated, featuring compact embedded devices that are deployed densely and at scale, efficient designs are indispensable to achieve desired operational lifetimes and satisfy high bandwidth demands.
Meeting these partly conflicting requirements, however, is challenging due to imperfections of wireless communication and resource constraints along several dimensions, for example, computing, memory, and power constraints of the devices. More precisely, frequent and correlated message losses paired with very limited bandwidth and varying delays for the message exchange significantly complicate the control design. In addition, since communication ranges are limited, messages must be relayed over multiple hops to cover larger distances, such as an entire factory. Although the resulting mesh networks are more robust against interference, efficient communication is a major challenge as wireless imperfections get amplified, and significant coordination effort is needed, especially if the networks are dynamic.
CPS combine various research disciplines, which are often investigated in isolation, ignoring their complex interaction. However, to address this interaction and build trust in the proposed solutions, evaluating CPS using real physical systems and wireless networks paired with formal guarantees of a system’s end-to-end behavior is necessary. Existing works that take this step can only satisfy a few of the abovementioned requirements. Most notably, multi-hop communication has only been used to control slow physical processes while providing no guarantees. One of the reasons is that the current communication protocols are not suited for dynamic multi-hop networks.
This thesis closes the gap between existing works and the diverse needs of emerging wireless CPS. The contributions address different research directions and are split into two parts. In the first part, we specifically address the shortcomings of existing communication protocols and make the following contributions to provide a solid networking foundation:
• We present Mixer, a communication primitive for the reliable many-to-all message exchange in dynamic wireless multi-hop networks. Mixer runs on resource-constrained low-power embedded devices and combines synchronous transmissions and network coding for a highly scalable and topology-agnostic message exchange. As a result, it supports mobile nodes and can serve any possible traffic patterns, for example, to efficiently realize distributed control, as required by emerging CPS applications.
• We present Butler, a lightweight and distributed synchronization mechanism with formally guaranteed correctness properties to improve the dependability of synchronous transmissions-based protocols. These protocols require precise time synchronization provided by a specific node. Upon failure of this node, the entire network cannot communicate. Butler removes this single point of failure by quickly synchronizing all nodes in the network without affecting the protocols’ performance.
In the second part, we focus on the challenges of integrating communication and various control concepts using classical time-triggered and modern event-based approaches. Based on the design, implementation, and evaluation of the proposed solutions using real systems and networks, we make the following contributions, which in many ways push the boundaries of previous approaches:
• We are the first to demonstrate and evaluate fast feedback control over low-power wireless multi-hop networks. Essential for this achievement is a novel co-design and integration of communication and control. Our wireless embedded platform tames the imperfections impairing control, for example, message loss and varying delays, and considers the resulting key properties in the control design. Furthermore, the careful orchestration of control and communication tasks enables real-time operation and makes our system amenable to an end-to-end analysis. Due to this, we can provably guarantee closed-loop stability for physical processes with linear time-invariant dynamics.
• We propose control-guided communication, a novel co-design for distributed self-triggered control over wireless multi-hop networks. Self-triggered control can save energy by transmitting data only when needed. However, there are no solutions that bring those savings to multi-hop networks and that can reallocate freed-up resources, for example, to other agents. Our control system informs the communication system of its transmission demands ahead of time so that communication resources can be allocated accordingly. Thus, we can transfer the energy savings from the control to the communication side and achieve an end-to-end benefit.
• We present a novel co-design of distributed control and wireless communication that resolves overload situations in which the communication demand exceeds the available bandwidth. As systems scale up, featuring more agents and higher bandwidth demands, the available bandwidth will be quickly exceeded, resulting in overload. While event-triggered control and self-triggered control approaches reduce the communication demand on average, they cannot prevent that potentially all agents want to communicate simultaneously. We address this limitation by dynamically allocating the available bandwidth to the agents with the highest need. Thus, we can formally prove that our co-design guarantees closed-loop stability for physical systems with stochastic linear time-invariant dynamics.:Abstract
Acknowledgements
List of Abbreviations
List of Figures
List of Tables
1 Introduction
1.1 Motivation
1.2 Application Requirements
1.3 Challenges
1.4 State of the Art
1.5 Contributions and Road Map
2 Mixer: Efficient Many-to-All Broadcast in Dynamic Wireless Mesh Networks
2.1 Introduction
2.2 Overview
2.3 Design
2.4 Implementation
2.5 Evaluation
2.6 Discussion
2.7 Related Work
3 Butler: Increasing the Availability of Low-Power Wireless Communication Protocols
3.1 Introduction
3.2 Motivation and Background
3.3 Design
3.4 Analysis
3.5 Implementation
3.6 Evaluation
3.7 Related Work
4 Feedback Control Goes Wireless: Guaranteed Stability over Low-Power Multi-Hop Networks
4.1 Introduction
4.2 Related Work
4.3 Problem Setting and Approach
4.4 Wireless Embedded System Design
4.5 Control Design and Analysis
4.6 Experimental Evaluation
4.A Control Details
5 Control-Guided Communication: Efficient Resource Arbitration and Allocation in Multi-Hop Wireless Control Systems
5.1 Introduction
5.2 Problem Setting
5.3 Co-Design Approach
5.4 Wireless Communication System Design
5.5 Self-Triggered Control Design
5.6 Experimental Evaluation
6 Scaling Beyond Bandwidth Limitations: Wireless Control With Stability Guarantees Under Overload
6.1 Introduction
6.2 Problem and Related Work
6.3 Overview of Co-Design Approach
6.4 Predictive Triggering and Control System
6.5 Adaptive Communication System
6.6 Integration and Stability Analysis
6.7 Testbed Experiments
6.A Proof of Theorem 4
6.B Usage of the Network Bandwidth for Control
7 Conclusion and Outlook
7.1 Contributions
7.2 Future Directions
Bibliography
List of Publications
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