Tesis: "Application connectée"

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Chaher, Yosra. "Cadre d'ingénierie pour l'innovation ouverte : application en santé connectée". Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30121.

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Face à nombreux défis, les organisations compétitives de nos jours sont celles qui transforment rapidement les nouvelles idées en nouveaux produits ou services. C'est pourquoi, elles cherchent à mieux maîtriser leur processus d'innovation et à le rendre plus efficace sur l'ensemble des fonctions de leur chaîne de valeur, depuis la phase de génération des idées jusqu'à leur mise sur le marché. De plus, au cours des quinze dernières années, les grandes entreprises ont ouvert leurs processus d'innovation en raison de la nécessité de cycles d'innovation de plus en plus courts et de délais de commercialisation réduits. Cependant, nous constatons qu'il n'y a pratiquement aucune approche formelle dans la littérature liée à la modélisation de l'innovation qui rationalise la gestion du processus d'innovation dite "ouverte". Dans ce contexte, nous développons un cadre méthodologique en ciblant in fine le processus de l'innovation ouverte afin de le formaliser et rationaliser sa gestion. La démarche de l'ingénierie dirigée par les modèles mise en place nous permet de proposer une approche formelle pour bien structurer la gestion de l'innovation ouverte. Pour cela, notre recherche s'est focalisée dans un premier temps sur la conception d'un modèle conceptuel qui décrit les connaissances inscrites dans le périmètre du management de l'innovation ouverte grâce à une formalisation en UML. Ce modèle conceptuel est considéré comme le socle de référence de notre cadre méthodologique puisqu'il est générique et peut être appliqué à toute innovation. Nous avons ensuite proposé un modèle de cycle de vie qui décrit le processus de l'innovation ouverte, fondé sur la collaboration et l'échange entre les différents acteurs. Nous avons détaillé ce modèle en processus métiers collaboratifs à l'aide des diagrammes BPMN pour décrire les activités opérationnelles, et des diagrammes DMN pour cadrer les activités de prise de décisions. Enfin, nous avons illustré ce cadre méthodologique sur deux cas d'études liés au domaine de la santé connectée, afin de tester sa validité
Faced with many challenges, competitive organizations today are those that quickly transform new ideas into new products or services. This is why they are seeking to better control their innovation process and make it more efficient across all functions of their value chain, from the idea generation phase to their launch. In addition, over the past 15 years, large companies have opened up their innovation processes due to the need for shorter innovation cycles and shorter time to market. However, we note that there is virtually no formal approach in the literature related to innovation modeling that streamlines the management of the so-called "open" innovation process. In this context, we are developing a methodological framework by targeting the open innovation process in order to formalize it and rationalize its management. The Model-Driven Engineering approach implemented allows us to propose a formal approach to properly structure the management of open innovation. To this end, our research focused initially on the design of a conceptual model that describes the knowledge included in the scope of open innovation management through formalization in UML. This conceptual model is considered the reference base of our methodological framework since it is generic and can be applied to any type of innovation. Then, we proposed a life cycle model that describes the process of open innovation, based on collaboration and exchange between the different actors. We have detailed this model into collaborative business processes using BPMN diagrams to describe operational activities, and DMN diagrams to frame decision making activities. Finally, we illustrated this methodological framework on two case studies related to the field of connected health, in order to test its validity

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2

Bouali, Baghli Rayhana. "Approche sémantique de la conception de services connectés : cadre d'architecture, algorithmique de composition, application à la maison connectée". Electronic Thesis or Diss., Paris, ENST, 2017. http://www.theses.fr/2017ENST0072.

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Dans le contexte de l’Internet des Objets, la conception de services connectés – c’est-à-dire de services portés par des objets connectés – nécessite une approche de bout en bout pour non seulement répondre aux attentes des bénéficiaires de ces services mais aussi pour adapter le fonctionnement de ces services à des conditions d’exécution très variées allant de la maison à la ville connectée. L’approche sémantique proposée par cette thèse offre un niveau d’abstraction qui permet aux concepteurs de services de se concentrer sur les aspects fonctionnels des services et des objets. Elle s’inscrit dans un cadre d’architecture plus large qui aborde, en plus de ce niveau sémantique, les aspects plus opérationnels de mise en oeuvre de ces services (niveau Artefacts) dans des environnements techniques éventuellement hétérogènes (niveau Ressources). En proposant cette approche sémantique de conception, la thèse vise plusieurs objectifs qui peuvent être regroupés en trois catégories. La première catégorie d’objectifs est de décloisonner le monde actuel des services connectés en découplant les services des objets connectés et en permettant le partage d’objets par plusieurs services connectés. L’ouverture induite par ces premiers objectifs conduit à viser une deuxième catégorie d’objectifs qui a trait à la composition des services connectés. Chaque service devra être conscient et adopter un comportement compatible avec les autres éléments de son contexte d’exécution. Ces éléments de contexte comprennent bien sûr les autres services mais aussi les phénomènes physiques et les actions des occupants des espaces concernés. Enfin, la troisième catégorie d’objectifs s’adresse plus s’adresse plus particulièrement aux bénéficiaires des services connectés afin d’optimiser l’expérience utilisateur par des attentes mieux prises en compte et des automatismes respectueux des comportements humains. Le fondement théorique de l’approche sémantique proposée dans cette thèse s’appuie sur un méta-modèle qui permet de définir les éléments de modélisation nécessaires pour modéliser les services, les objets connectés et les comportements des services sous forme déclarative
In the context of the Internet of Things, the design of connected services - that is, services supported by connected objects - requires an end-to-end approach to not only meet the expectations of the recipients of these services but also to adapt the operation of these services to a wide range of execution conditions spreading from smart homes to smart cities. The semantic approach proposed in this thesis provides a level of abstraction that allows service designers to focus on the functional aspects of services and objects. It is part of a larger architecture framework that addresses, in addition to this semantic level, the more operational aspects of implementation of these services (Artifacts level) in potentially heterogeneous technical environments (Resources level). By proposing this semantic design approach, the thesis aims at achieving several objectives that can be grouped into three categories. The first category of objectives is to decompartmentalize the current world of connected services by decoupling services from connected objects and allowing the sharing of objects by several connected services. The openness induced by these first objectives leads to a second category of objectives that relates to the composition of connected services. Each service will have to be aware and adopt a behavior compatible with the other elements of its execution context. These contextual elements include of course the other services but also the physical phenomena and the actions of the occupants of the spaces concerned. Finally, the third category of objectives focusses on at the recipients of connected services in order to optimize the user experience through better requirement management and automatisms respectful of human behaviors. The theoretical basis of the semantic approach proposed in this thesis is a meta-model that defines the modeling elements needed to model services, connected objects and service behaviors in a declarative form

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3

Lobbes, Hervé Bertrand Antoine. "Application connectée pour le recueil participatif et le diagnostic à partir de selfies de l'œil : détection de carence martiale". Electronic Thesis or Diss., Université Clermont Auvergne (2021-...), 2024. http://www.theses.fr/2024UCFA0166.

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Contexte : La carence en fer est fortement prévalente en population générale, notamment chez les femmes réglées. La carence en fer peut entraîner l'apparition d'une anémie, altère la qualité de vie et les performances cognitives et est responsable d'une augmentation de la morbidité pendant la grossesse. La pâleur muqueuse, bien visible au niveau conjonctival et la coloration bleutée de la sclère sont des signes cliniques classiques mais subjectifs d'anémie et de carence en fer. Le diagnostic de certitude est coûteux, eu égard à la prévalence de la pathologie et repose sur la réalisation d'un hémogramme et d'un dosage de ferritine sérique. Notre objectif est de mettre au point un dispositif non invasif de dépistage de l'anémie et de la carence en fer par analyse en image artificielle d'images de l'œil.Patientes et méthodes : nous avons construit un modèle d'apprentissage profond pour la prédiction de l'anémie (hémoglobine < 12 g/dL) et de la carence en fer (ferritine < 20 µg/L) à partir de photographies de l'œil (sclère et conjonctive palpébrale inférieure). Les images étaient réalisées de façon standardisées avec un smartphone et une caméra professionnelle d'ophtalmologie (Lacrydiag®). Pour chaque sujet, 4 images avec la sclère et 2 images avec la sclère et la conjonctive (par traction douce sur la paupière inférieure) étaient réalisées par œil selon chacune des méthodes (smartphone et caméra Lacrydiag). Nous avons recruté prospectivement des patientes adultes ayant bénéficié d'un dépistage de l'anémie ferriprive (hémogramme et ferritine). Les pathologies hémolytiques, les antécédents de pathologies héréditaires du tissu conjonctif, ou toute intervention ou traumatisme susceptibles de modifier l'aspect de l'œil étaient des critères d'exclusion.Résultats : Nous avons inclus 202 femme (âge médian 22 ans, hémoglobine médiane 13 g/dL), dont 49.5% étaient carencées en fer (ferritine médiane 11 µg/L, Q1-Q3 : 7-14) et 17% étaient anémiques (hémoglobine médiane 11.4 g/dL, Q1-Q3 : 10.8-11.7). Après reconstruction en « High Dynamic Range » des images smartphone, une segmentation automatisée des photographies fournissait des masques d'images comprenant uniquement les zones d'intérêt (sclère, conjonctive). Ces masques était soumis à un panel de réseaux neuronaux convolutionnels (plateforme Autokeras, Université du Texas), permettant de trouver le meilleur modèle prédictif. Une tendance non significative (p = 0.06) entre les valeurs de ferritine prédites et réelles était identifié sur l'algorithme en régression sur les images HDR du smartphone. Aucune corrélation n'était identifiée en régression pour l'hémoglobine quel que soit le type d'image, ni pour la ferritine sur les images Lacrydiag. En classification, les meilleurs résultats pour la classification de la carence en fer étaient obtenus avec un seuil de ferritine < 15 µg/L sur les images HDR de la sclère, avec une sensibilité de 59%, une spécificité de 75.6% et une valeur prédictive négative de 75%. Pour la classification de l'anémie, l'algorithme sur les images HDR de la conjonctive donnait une sensibilité de 66.7%, une spécificité de 77.6%, une valeur prédictive positive de 38.1% et une valeur prédictive négative de 91.8%.Conclusion : les performances de l'algorithme pour la prédiction de l'anémie à partir d'images smartphone de la conjonctive et de la sclère sont encourageantes. En régression, les résultats sont non significatifs mais une tendance est notée pour la prédiction de la ferritine sur les images HDR. Pour le dépistage de la carence en fer, l'algorithme de classification offre une sensibilité moyenne. Afin d'améliorer les performances de cet outil de dépistage, il est indispensable d'augmenter les effectifs de la base d'apprentissage, et de la valider dans d'autres populations hommes, patients âgés comorbides)
Background: Iron deficiency is highly prevalent in the general population, particularly in women of childbearing age. Iron deficiency increases pregnancy morbidity, impairs the quality of life through decrease of cognitive performance and can lead to anemia. Mucosal pallor, easily identified on the palpebral conjunctiva is widely used to predict anemia. Iron deficiency may also induce a bluish discoloration of the sclera, but these signs are subjective. However, certainty diagnosis lays on full blood count and serum ferritin dosage, representing a huge economic burden given to the prevalence of iron deficiency anemia. We aimed to build an affordable effective non-invasive diagnostic test through deep-learning eye image analysis to predict iron deficiency and anemia.Patients and methods: We built a deep-learning algorithm to detect anemia (hemoglobin < 12 g/dL) and iron deficiency (ferritin < 20 µg/L) through eye image analysis. For each subject, four images with the sclera and two images with the sclera and conjunctiva (by gentle traction on the lower eyelid) were taken per eye using a smartphone and a professional camera (Lacrydiag®) in similar lighting conditions. We prospectively included healthy adult women screened for iron deficiency anemia during routine medical practice. Hemolytic disease, connective tissue disease, eye surgery or trauma were exclusion criteria.Results: Among the 202 women recruited (median age 22 years, median hemoglobin 13 g/dL), 49.5% had iron deficiency (median ferritin 11 µg/L, Q1-Q3: 7-17) and 17 were anemic (median hemoglobin 11.4 g/dL, Q1-Q3: 10.8-11.7). Smartphone images were merged into High dynamic range format: mask of the sclera and conjunctiva (automated segmentation) were analyzed with a panel of convolutional neural network provided by Autokeras platform (Texas University) to identify the most efficient model. No significant correlation was found in regression analysis between real and predicted hemoglobin values with smartphone and Lacrydiag® images. Sensitivity and specificity for the prediction of iron deficiency (classification algorithm, ferritin < 15 µg/L) were 59% and 75.6% respectively with smartphone sclera images analysis (positive predictive value 59.8%, negative predictive value 75%). Sensitivity and specificity for the prediction of anemia (classification algorithm, hemoglobin < 12 g/dL) were 66.7% and 77.6% respectively with conjunctiva smartphone images analysis (positive predictive value 38.1%, negative predictive value 91.8%).Conclusion: the convolutional neural network analysis of the sclera and conjunctiva smartphone HDR image analysis is efficient to predict anemia. The model failed to predict hemoglobin level. Results for the ferritin prediction on HDR image analysis are encouraging but further analysis are still required. For iron deficiency screening, the classification model provided a modest sensitivity. To improve the performance of our model, it appears essential to increase the size of the learning database and to validate its efficacy in other populations (men, elderly comorbid patients)

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4

Adoue, François. "La mobilité connectée au quotidien : les usages du smartphone dans les transports en commun franciliens". Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1170.

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Cette thèse porte sur l’hybridation des dimensions virtuelle et corporelle de la mobilité. Elle interroge les effets de la mise en connexion de la mobilité quotidienne, et en particulier de la mobilité pendulaire, sous la double impulsion de la diffusion du smartphone et de l’amélioration de la qualité de la connexion aux réseaux de télécommunication dans les transports en commun. La mobilité, que nous décrivons comme connectée, permet à la fois le déploiement d’activités numériques au cours du déplacement, et l’accès facilité à une information personnalisée sur les conditions d’un déplacement projeté ou en cours via les applications d’aide à la mobilité sur smartphone. La problématique générale de ce travail de recherche peut être comprise à travers l’interrogation suivante : comment les usagers des transports en commun se saisissent-ils de la mise en connexion de la mobilité pour agir sur les contraintes spatio-temporelles du quotidien ? Trois hypothèses structurent cette recherche. La première hypothèse est celle d’un effet positif de la mise en connexion de la mobilité sur la valorisation du temps de déplacement. La deuxième hypothèse est celle de la recomposition, à l’heure de la mobilité connectée, de la spécificité de l’espace-temps du déplacement au regard des activités qui y sont déployées. La troisième hypothèse est celle d’une meilleure maîtrise de la mobilité résultant de l’ancrage dans les habitudes du recours à l’information personnalisée au moyen d’applications d’aide à la mobilité. À partir d’une enquête par entretiens semi-directifs réalisée entre 2013 et 2014 et d’une enquête par la passation de questionnaires en ligne en 2015, nous avançons, en réponse à ces trois hypothèses, l’idée que la mise en connexion de la mobilité soutient une banalisation du déplacement. À défaut de produire une valorisation du temps de déplacement, le smartphone atténue, pour l’individu, les effets négatifs des variations des conditions de trajets sur le niveau de confort du déplacement. De plus, du point la mise en connexion de la mobilité rend plus perméable cet espace-temps au déploiement d’activités structurant par ailleurs le quotidien. Enfin, les applications d’aide à la mobilité offrent, outre des voies d’optimisation temporelle des déplacements quotidiens, une forme de sécurisation de la mobilité
This thesis focuses on hybridity between virtual and corporeal mobility. We study the effects of growing connectivity on daily mobility, and especially on commuting. ‘Connected’ mobility is characterised by the large-scale diffusion of smartphones and the improvement of broadband connection in public transportation. ‘Connected’ mobility allows travellers to use a wider range of on-trip activities and to receive personalised information about their current or future trips. The main issue is to determine how public transportation users use ‘connected’ mobility to their advantage to soften daily time-space constraints. Three hypotheses led this research. The first is the hypothesis of the valorisation of travel time through the use of ICT devices such as smartphones. The second is about the reshaping of mobility time-space through connectivity, regarding the activities practised by travellers in their daily lives. The third concerns the better control of daily mobility allowed by the use of mobile apps that provide personalised information. The study is based on two surveys. The first occurred during the years 2013 and 2014. It is composed of in-depth semi-directive interviews. The second is a large-scale survey led by on-line questionnaires in 2015. The main results support the idea that the growing connectivity of mobility underlines a banalisation of mobility. The use of smartphones does not clearly imply a greater valorisation of travel time, but softens the negative effects on travel comfort due to the variations of travel conditions. Moreover, the growing connectivity of mobility time-space allows the travellers to import in this specific time-space their daily activities. Finally, the mobile apps providing personalised information about mobility authorise travel optimisation but also secure the daily trips, improving the feeling of control on mobility

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Bardot, Sandra. "Conception et évaluation de techniques d'interaction non-visuelle basées sur un dispositif personnel : application à l'exploration de cartes numériques par des personnes avec déficience visuelle". Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30061.

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Pour les personnes déficientes visuelles, les documents en relief sont importants pour l'accès à la connaissance. Afin de répondre aux spécificités de la perception haptique, il est nécessaire de simplifier la quantité d'information disponible au sein d'un document en relief. Ce processus s'appelle l'adaptation du contenu et repose sur l'intervention d'un spécialiste qui sait concevoir un contenu adapté à l'exploration tactile et à la compétence des utilisateurs. Comme la modification est impossible, celui-ci doit être refait à chaque changement. Ainsi, la possibilité d'utiliser et d'explorer un contenu numérique plutôt que physique représente une alternative intéressante. Un grand nombre de données numériques en accès libre est disponible, et l'adaptation des données peut être réalisée grâce à des algorithmes prévus à cet effet. Cependant, les documents numériques sont par essence visuels, et par conséquent inaccessibles aux personnes déficientes visuelles en l'état. L'état de l'art concernant l'exploration haptique de données numériques fait apparaitre un ensemble de solutions reposant sur un artefact (comme une souris à retour de force). Cette approche présente de nombreuses limitations, notamment le fait de parcourir le document avec un seul point de contact. Une approche plus fonctionnelle consiste à laisser l'utilisateur explorer un graphique numérique avec ses mains : chaque doigt peut alors être considéré comme un curseur. Les feedback sonore et vibratoire sont déclenchés en fonction de la position du doigt sur le document numérique. Cependant, il est nécessaire de connaitre les éléments importants d'un graphique (c'est-à-dire les éléments qui déclencheront des feedbacks), ainsi que le rôle de chacun des doigts au cours de l'exploration. La problématique de cette thèse porte sur l'exploration des données spatiales numériques en reposant sur des interactions haptiques. L'objectif est double : 1) comprendre comment les personnes déficientes visuelles explorent les graphiques en relief ; et 2) proposer des techniques d'interaction haptique, basées sur des dispositifs personnels et transportables, qui permettent aux utilisateurs déficients visuels d'explorer des graphiques numériques dans différents contextes (à la maison ou à l'école par exemple). Pour répondre au premier point, nous avons réalisé deux études portant sur les stratégies d'exploration des documents en relief, en fonction du niveau d'expertise des utilisateurs. Nous avons montré que les stratégies utilisées dépendent de l'expertise mais aussi du type de document exploré. Pour répondre au deuxième point, nous avons proposé de nouvelles techniques d'interaction reposant sur l'utilisation d'une montre connectée qui permet des feedbacks localisés. Nous avons mené deux études expérimentales concernant la conception et l'évaluation de techniques d'interaction haptiques basées sur la montre. La première étude portait sur la comparaison de l'exploration de graphiques physiques (en relief) à celle de graphiques numériques virtuels. Les résultats montrent que deux de nos techniques d'interaction permettent une exploration de graphiques numériques plus rapide que l'exploration de graphiques en relief. Notre deuxième étude visait à développer et évaluer des techniques d'interaction permettant l'utilisation des deux mains lors de l'exploration de contenus numériques. Les résultats montrent que les stratégies bimanuelles reposant sur un feedback bilatéral localisé améliorent les performances d'exploration de graphiques numériques. Les résultats de ces études mettent en avant les avantages d'une interaction haptique bimanuelle. Combinées à un dispositif de localisation et de suivi des mains, les techniques d'interaction développées sur une montre connectée pourraient permettre aux utilisateurs d'interagir avec des contenus numériques dans de nombreuses situations de la vie quotidienne
For visually impaired people, raised-line documents are important for access to knowledge. In order to respond to the specificities of haptic perception, it is necessary to simplify the amount of information available within a raised-line document. This process is called the adaptation of the content and relies on the intervention of a specialist who knows how to design content adapted to tactile exploration. As the modification is impossible, it must be printed again at each changes. Thus, the ability to use and explore digital rather than physical content is an interesting alternative. A large number of free access numerical data is available, and the adaptation of the data can be carried out by means of algorithms provided for this purpose. However, digital documents are essentially visual, and therefore inaccessible to visually impaired people as they are. The state of the art regarding haptic exploration of digital data reveals a set of solutions based on an devices (like a force feedback mouse). This approach has many limitations, including browsing the document with a single point of contact. A more functional approach is to let the user explore a digital graph with his hands: each finger can then be considered as a cursor. Feedback audio and vibration are triggered depending on the position of the finger on the digital document. However, it is necessary to know the important elements of a graph (the elements that will trigger feedback), as well as the role of each finger during the exploration. The problematic of this thesis deals with the exploration of digital spatial data by relying on haptic interactions. The goal is twofold: 1) understand how visually impaired people explore raised-line diagrams; and 2) offer haptic interaction techniques, based on personal and wearable devices, that allow visually impaired users to explore digital diagrams in different contexts (at home or at school, for example). To answer the first point, we conducted two studies on the exploration strategies of raised-line documents, according to the level of expertise of the users. We have shown that the strategies used depend on the expertise but also the type of document explored. To answer the second point, we proposed new interaction techniques based on the use of a smartwatch that allows localized feedback. We conducted two experimental studies regarding the design and evaluation of watch-based haptic interaction techniques. The first study focused on comparing the exploration of physical diagrams with that of virtual digital diagrams The results show that two of our interaction techniques allow for faster digital graphics exploration than the exploration of 3D graphics. Our second study aimed to develop and evaluate interaction techniques allowing the use of two hands while exploring digital content. The results show that bimanual strategies based on localized feedback improve digital diagrams exploration performance. The results of these studies highlight the benefits of bimanual haptic interaction. Combined with a device for tracking and tracking hands, interaction techniques developed on a connected watch could enable users to interact with digital content in many situations of everyday life

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El, achkar Maria. "Contribution au Dimensionnement et à la Commande d’un Générateur de type Cascade de Machines Asynchrones à Double Alimentation". Thesis, Cergy-Pontoise, 2016. http://www.theses.fr/2016CERG0814/document.

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Le travail présenté dans cette thèse est une contribution au dimensionnement et à la commande d’un générateur de type Cascade de Machines Asynchrones à Double Alimentation. Le modèle de la machine pour les simulations est basé sur une représentation modulaire qui découle du modèle de Park de deux machines asynchrones doublement alimentées distinctes, en respectant deux systèmes de référence. Le modèle dynamique est ensuite étendu pour décrire la machine dans un repère unifié. Cette représentation est cruciale pour le dimensionnement de la machine et la synthèse de la commande. Le domaine de fonctionnement de la cascade en régime permanent est exploré. Une méthode analytique générique est proposée pour établir les plages de puissances active-réactive. Les courbes limites sont définies par rapport aux grandeurs nominales de la machine. L’étude prend en compte l’effet de saturation du circuit magnétique. Il est prouvé que la capacité en puissance de la machine est déterminée par les valeurs maximales des courants statoriques et peut être soumise à plusieurs limitations. L’approche analytique est testée et validée par des mesures expérimentales. Deux cas sont considérés pour la commande de la cascade : un générateur raccordé au réseau et un générateur autonome. Pour la connexion au réseau l’application visée est les éoliennes de grande puissance. Une nouvelle méthode pour l’extraction de la puissance maximale d’une éolienne à vitesse variable est proposée. Le système est contrôlé dans le but de fournir une puissance maximale quasi-constante indépendamment des fluctuations du vent. En plus de l’optimisation de la puissance, le facteur de puissance est également ajusté selon les normes de raccordement standard imposées par les services système, et les limites de fonctionnement de l’unité intégrée. Une commande vectorielle sans capteur de tension, basée sur une orientation suivant un flux virtuel, est appliquée pour la régulation découplée des puissances active et réactive. Pour le fonctionnement en mode isolé, l’application visée est la génération électrique pour système avionique embarqué. Deux réseaux de distribution sont traités : réseau AC à fréquence fixe et réseau DC. Dans les deux cas, la commande est élaborée dans le but de maintenir une tension de sortie constante. Le fonctionnement de la cascade alimentant une charge triphasée déséquilibrée est également étudié. Des schémas de contrôle servant à la compensation du déséquilibre des tensions statoriques sont développés. Deux méthodes de compensation sont proposées : l’une basée sur le principe de deux repères tournants et l’autre sur un correcteur répétitif. Les approches présentées sont validées par simulation avec Matlab/Simulink et par expérimentation
This thesis is a contribution to the power sizing and the control of a Cascaded Doubly Fed Induction Generator (CDFIG). The machine model for simulation is based on a modular representation, derived from the Park model of two distinct Doubly Fed Induction Machines expressed in their own reference frames. The dynamic model of the cascaded machine is then extended to be described in a unified reference frame. This representation is convenient for the sizing of the machine and for the design of the controller. The steady state power operating margins of the cascaded machine are investigated. A generic analytic method is suggested to derive the active-reactive power domain. The limit curves are defined in terms of the rated quantities of the machine. The study takes into account the magnetic circuit saturation effect. It is proven that the power capability of the machine is determined by the stator current maximum values and is subject to several limitations. The analytical approach is tested and validated by experimental measurements. The CDFIG is controlled in grid-connected and standalone operation modes. In grid-connected application, the attention is paid to high power wind generation systems. A new maximum power tracking of a variable speed wind turbine is suggested. The generating plant is carried to provide a quasi-constant maximum power regardless wind fluctuations. In addition to active power optimization the power factor is adjusted according to the grid code requirements and the operating domain of the integrated unit. A virtual flux oriented vector control is applied for the decoupled regulation of active and reactive powers, leading to grid voltage sensorless operation. In standalone operating mode, the study treats in particular the embedded aircraft power system generation. Two distribution networks are considered: constant frequency AC network and DC network. In both cases, the control aims to maintain a constant output voltage. The operation of the CDFIG supplying unbalanced three-phase load is further explored. Control schemes to cope with unbalanced stator voltage conditions are developed. Two compensation methods are elaborated: the first dealing with dual rotating frames and the second is based on repetitive controller. Simulations with Matlab/Simulink software and experiments validate the control approaches

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Sarisin, Mustafa Nevzat. "Design Of A Connected Pipe Test Facility For Ramjet Applications". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606078/index.pdf.

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ABSTRACT DESIGN OF A CONNECTED PIPE TEST FACILITY FOR RAMJET APPLICATIONS SARISIN, Mustafa Nevzat M.S., Department of Mechanical Engineering Supervisor: Asst. Prof. Dr. Abdullah ULAS Co-Supervisor: Prof. Dr. Kahraman ALBAYRAK April 2005, 164 pages Development of the combustor of a ramjet can be achieved by connected pipe testing. Connected pipe testing is selected for combustor testing because pressure, temperature, Mach number, air mass flow rate can be simulated by this type of testing. Real time trajectory conditions and transition from rocket motor (booster) to ramjet operation can also be tested. The biggest advantage of connected pipe testing is the low operation cost and simplicity. Air mass flow rate requirement is less than the others which requires less air storage space and some components like supersonic nozzle and ejector system is not necessary. In this thesis, design of a connected pipe test facility is implemented. Three main systems are analyzed
air storage system, air heater system and test stand. Design of air storage system includes the design of pressure vessel and pressure &
flow regulation system. Pressure and flow regulation system is needed to obtain the actual flow properties that the combustor is exposed to during missile flight. Alternatives for pressure and air mass flow rate regulation are considered in this study. Air storage system designed in this thesis is 27.8 m3 at 50 bar which allows a test duration of 200 seconds at an average mass flow rate of 3 kg/s. Air heater system is utilized to heat the air to simulate the aerodynamic heating of the inlet. Several different combustion chamber configurations with different flame holding mechanisms are studied. The most efficient configuration is selected for this study. Combustion analysis of the air heater is performed by FLUENT CFD Code. Combustion process and air heater designs are validated using experimental data. Designed air heater system is capable of supplying air at a temperature range of 400-1000 K and mass flow rate range of 1.5-8 kg/s at Mach numbers between 0.1-0.5 and pressure between 2-8 bar. Finally the design of the test stand and ramjet combustor analysis are completed. 3D CAD models of the test stand are generated. Ramjet combustor that will be tested in the test setup is modeled and combustion analysis is performed by FLUENT CFD Code. The ramjet engine cruise altitude is 16 km and cruise Mach number is 3.5. Key-words: Air Breathing Engines, Ramjet, Connected Pipe, Direct Connect, Vitiator.

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8

Moohan, R. "Connected health : applications in community pharmacy practice". Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680058.

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As the population ages, the use of information technology and telecommunications in healthcare delivery (often known as Connected Health, telehealth or e-health) has been proposed as a means of providing . patient-centred care to those with chronic conditions. Little research has been conducted into the involvement of community pharmacists in Connected Health delivery. This thesis aimed to investigate the potential role of community pharmacists in the delivery of Connected Health services. A systematic content analysis of print media was performed to explore reporting of Connected Health in UK and US newspapers. A qualitative interview study was conducted with community pharmacists and key stakeholders in Canada and Northern Ireland to gather their views on community pharmacist involvement in Connected Health. Informed by the latter qualitative study, an online questionnaire was distributed to community pharmacists in Northern Ireland to explore their views regarding their potential role in Connected Health. Finally, a feasibility study was carried out, in which community pharmacists sent patients mobile telephone medication reminders and remotely monitored their blood pressure . . Connected Health was positively reported by the print media in the US and the UK. Community pharmacist and key stakeholder interviewees were supportive of community pharmacist involvement in Connected Health, believing it would extend and promote ' their role. However, they had concerns regarding appropriate remuneration. Similar views were obtained from community pharmacist questionnaire respondents. The feasibility study showed that a community pharmacy-based Connected Health programme could be successfully implemented on a small scale. Participants involved were positive about community pharmacist involvement in Connected Health. Community pharmacist involvement in Connected Health has the potential to improve patient outcomes and ease pressure on the health service. However, barriers such as funding and general practitioner acceptance would need to be overcome and a sound evidence base established before routine pharmacist involvement becomes a reality.

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9

Issoufaly, Taher. "Physical Tracking : menaces, performances et applications". Thesis, La Réunion, 2019. http://www.theses.fr/2019LARE0017/document.

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La récente émergence des smartphones et des objets connectés a révolutionné le mode de vie des utilisateurs. Ces dispositifs ubiquitaires et équipés de plusieurs interfaces sans fil de communication, sont rapidement devenus indispensables dans la vie quotidienne des utilisateurs avec une utilisation intensive. Les interfaces sans fil de ces objets connectés émettent périodiquement des informations, certaines sont spécifiques aux utilisateurs et permettent par effet de bord d’identifier et de suivre leur déplacements. Le suivi des utilisateurs via les informations fortuitement émises par leurs périphériques sans fil se nomme le Wireless Physical Tracking. Les possibilités offertes par le Wireless Physical Tracking ont suscité un fort intérêt. Plusieurs applications se sont développés et ont permis d’apporter de l’innovation dans plusieurs domaines. Des sociétés de marketing l’utilisent afin de proposer à leurs clients de la publicité ciblée en fonction de leurs parcours dans leur zone d’activité. À une échelle plus grande, les villes intelligentes, ou smart-cities analysent le mouvement des utilisateurs afin d’apporter des services pour le confort des habitants. Enfin, dans le domaine de la recherche, les réseaux Ad-Hoc mobiles et autres DTN nécessitent de s’intéresser à cette pratique car l’étude de la mobilité des utilisateurs représentent un élément clé pour améliorer les performances de ce type de réseau. Cependant, la collecte de ces informations sans le consentement des utilisateurs ou sans qu’elles soient correctement protégées représentent un risque réel pour leur vie privée. C’est autour de ce contexte que s’articule cette thèse divisée en deux parties. La première présente les technologies PAN et WAN, l’état de l’art des méthodes de Wireless Physical Tracking et les contre mesures adoptés. La deuxième partie présentent les contributions de la thèse qui visent à proposer de nouvelles méthodes de suivi, analyser les performances de celles-ci face aux méthodes existantes et dans le cas particulier de l’application de crowd-localisation, à proposer des méthodes de suivi respectueuse de la vie privée
The recent rise of smart-phones and connected objects has a deep impact its users lifestyle. In 2017, more than a billion and a half smart-phones were sold around the world. These ubiquitous devices, equipped with several wireless communication interfaces, have quickly become essential in the daily life of users with an intensive use. The wireless interfaces of these connected objects periodically transmit information on the network, some of which are user-specific and allow to identify and track their mobility. Tracking users by collecting the information generated by their wireless devices is called Wireless Physical Tracking. The opportunities offered by the Wireless Physical Tracking raised a lot of interest. Several applications have been developed and have brought innovation in several areas. Marketing companies use it to offer to their customers targeted advertising based on their movements in their area of activity. On a larger scale, Smart Cities or smart-cities analyse the movement of users in order to provide services for their inhabitants. Finally, in the field of research in mobile Ad-Hoc networks and DTNs, users mobility is a key element which need to be collected and analysed. However, the collection of this information without the consent of the users or without being properly protected induce a real risk to their privacy. It is around this context that this thesis is focused on. It’s divided into two parts. The first presents the PAN and WAN technologies, the state of the art of Wireless Physical Tracking methods and the adopted counter measures. The second part presents the contributions of the thesis which aims at developing new methods for Physical Tracking and analysing their performances compared to the existing methods. We first present an evaluate BPM, a bluetooth passive monitoring that allows to track the users of Classic Bluetooth device with a detection delay significantly lower than the methods previously used. We then focus on Bluetooth Low Energy and propose the use of a BLEB, a botnet of users tracking BLE objects with their smart-phones. Finally, we also focus on preserving users privacy through the proposal of PPCL, a privacy preserving crowdlocalisation method which allow to track users assets without being trackable

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10

Loulou, Hassan. "Verifying Design Properties at Runtime Using an MDE-Based Approach Models @Run.Time Verification-Application to Autonomous Connected Vehicles". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS405.

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Un véhicule autonome et connecté (ACV – pour Autonomous Connected Vehicle ) est un système cyber-physique où le monde réel et l’espace numérique virtuel se fusionnent. Ce type de véhicule requiert un processus de validation rigoureuse commençant à la phase de conception et se poursuivant même après le déploiement du logiciel. Un nouveau paradigme est apparu pour le monitorat continu des exécutions des logiciels afin d'autoriser des adaptations automatiquement en temps réel, systématiquement lors d’une détection de changement dans l'environnement d'exécution, d’une panne ou d’un bug. Ce paradigme s’intitule : « Models@Run.time ». Cette thèse s’inscrit dans le cadre des ACVs et plus particulièrement dans le contexte des véhicules qui collaborent et qui partagent leurs données d’une manière sécurisée. Plusieurs approches de modélisation sont déjà utilisées pour exprimer les exigences relatives au contrôle d'accès afin d’imposer des politiques de sécurité. Toutefois, leurs outils de validation ne tiennent pas compte les impacts de l'interaction entre les exigences fonctionnelles et les exigences de sécurité. Cette interaction peut conduire à des violations de sécurité inattendues lors de l'exécution du système ou lors des éventuelles adaptations à l’exécution. En outre, l’estimation en temps réel de l’état de trafic utilisant des données de type crowdsourcing pourrait être utilisée pour les adaptations aux modèles de coopération des AVCs. Cette approche n'a pas encore été suffisamment étudiée dans la littérature. Pour pallier à ces limitations, de nombreuses questions doivent être abordées:• L'évolution des exigences fonctionnelles du système doit être prise en compte lors de la validation des politiques de sécurité ainsi que les scénarios d'attaque doivent être générés automatiquement.• Une approche pour concevoir et détecter automatiquement les anti-patrons (antipatterns) de sécurité doit être développée. En outre, de nouvelles reconfigurations pour les politiques de contrôle d'accès doivent également être identifiées, validées et déployées efficacement à l'exécution.• Les ACVs doivent observer et analyser leur environnement, qui contient plusieurs flux de données dite massives (Big Data) pour proposer de nouveaux modèles de coopération, en temps réel.Dans cette thèse, une approche pour la surveillance de l'environnement des ACVs est proposée. L’approche permet de valider les politiques de contrôle d'accès et de les reconfigurer en toute sécurité. La contribution de cette thèse consiste à:• Guider les Model Checkers de sécurité pour trouver automatiquement les scénarios d'attaque dès la phase de conception.• Concevoir des anti-patterns pour guider le processus de validation, et développer un algorithme pour les détecter automatiquement lors des reconfigurations des modèles.• Construire une approche pour surveiller en temps réel les flux de données dynamiques afin de proposer des adaptations de la politique d'accès lors de l'exécution.L’approche proposée a été validée en utilisant plusieurs exemples liés aux ACVs, et les résultats des expérimentations prouvent la faisabilité de cette approche
Autonomous Connected Vehicles (ACVs) are Cyber-physical systems (CPS) where the computationalworld and the real one meet. These systems require a rigorous validation processthat starts at design phase and continues after the software deployment. Models@Runtimehas appeared as a new paradigm for continuously monitoring software systems execution inorder to enable adaptations whenever a change, a failure or a bug is introduced in the executionenvironment. In this thesis, we are going to tackle ACVs environment where vehicles tries tocollaborate and share their data in a secure manner.Different modeling approaches are already used for expressing access control requirementsin order to impose security policies. However, their validation tools do not consider the impactsof the interaction between the functional and the security requirements. This interaction canlead to unexpected security breaches during the system execution and its potential runtimeadaptations. Also, the real-time prediction of traffic states using crowd sourcing data could beuseful for proposition adaptations to AVCs cooperation models. Nevertheless, it has not beensufficiently studied yet. To overcome these limitations, many issues should be addressed:• The evolution of the system functional part must be considered during the validation ofthe security policy and attack scenarios must be generated automatically.• An approach for designing and automatically detecting security anti-patterns might bedeveloped. Furthermore, new reconfigurations for access control policies also must befound, validated and deployed efficiently at runtime.• ACVs need to observe and analyze their complex environment, containing big-datastreams to recommend new cooperation models, in near real-time.In this thesis, we build an approach for sensing the ACVs environment, validating its accesscontrol models and securely reconfiguring it on the fly. We cover three aspects:• We propose an approach for guiding security models checkers to find the attack scenariosat design time automatically.• We design anti-patterns to guide the validation process. Then, we develop an algorithmto detect them automatically during models reconfigurations. Also, we design a mechanismfor reconfiguring the access control model and we develop a lightweight modularframework for an efficient deployment of new reconfigurations.• We build an approach for the real-time monitoring of dynamic data streams to proposeadaptations for the access policy at runtime.Our proposed approach was validated using several examples related o ACVs. the results ofour experimentations prove the feasibility of this approach

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11

Konstantaras, Dimitrios y Mustafa Tahir. "Securing Network Connected Applications with Proposed Security Models". Thesis, Växjö University, School of Mathematics and Systems Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2022.

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In today’s society, serious organizations need protection against both internal and external attacks. There are many different technologies available that organizations can incorporate into their organization in order to enhance security for their networking applications. Unfortunately, security is way to often considered as an afterthought and therefore implemented as an external part of the applications. This is usually performed by introducing general security models and technologies.

However, an already developed, well structured and considered security approach – with proper implementation of security services and mechanisms – different security models can be used to apply security

within the security perimeter of an organization. It can range from built into the application to the edge of a private network, e.g. an appliance. No matter the choice, the involved people must possess security expertise to deploy the proposed security models in this paper, that have the soul purpose to secure applications.

By using the Recommendation X.800 as a comparison framework, the proposed models will be analyzed in detail and evaluated of how they provide the security services concerned in X.800. By reasoning about what security services that ought to be implemented in order to prevent or detect diverse security attacks, the organization needs to carry out a security plan and have a common understanding of the deﬁned security policies.

An interesting ﬁnding during our work was that, using a methodology that leads to low KLOC-values results in high security, though low KLOC-values and high security go hand-in-hand.

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12

Yadav, Arpit. "Reaching High Availability in Connected Car Backend Applications". Master's thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-229021.

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The connected car segment has high demands on the exchange of data between the car on the road, and a variety of services in the backend. By the end of 2020, connected services will be mainstream automotive offerings, according to Telefónica - Connected Car Industry Report 2014 the overall number of vehicles with built-in internet connectivity will increase from 10% of the overall market today to 90% by the end of the decade [1]. Connected car solutions will soon become one of the major business drivers for the industry; they already have a significant impact on existing solutions development and aftersales market. It has been more than three decades since the introduction of the first software component in cars, and since then a vast amount of different services has been introduced, creating an ecosystem of complex applications, architectures, and platforms. The complexity of the connected car ecosystem results into a range of new challenges. The backend applications must be scalable and flexible enough to accommodate loads created by the random user and device behavior. To deliver superior uptime, back-end systems must be highly integrated and automated to guarantee lowest possible failure rate, high availability, and fastest time-to-market. Connected car services increasingly rely on cloud-based service delivery models for improving user experiences and enhancing features for millions of vehicles and their users on a daily basis. Nowadays, the software applications become more complex, and the number of components that are involved and interact with each other is extremely large. In such systems, if a fault occurs, it can easily propagate and can affect other components resulting in a complex problem which is difficult to detect and debugg, therefore a robust and resilient architecture is needed which ensures the continuous availability of system in the wake of component failures, making the overall system highly available. The goal of the thesis is to gain insight into the development of highly available applications and to explore the area of fault tolerance. This thesis outlines different design patterns and describes the capabilities of fault tolerance libraries for Java platform, and design the most appropriate solution for developing a highly available application and evaluate the behavior with stress and load testing using Chaos Monkey methodologies.

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13

MALINVERNO, MARCO. "Safety Applications and Measurement Tools for Connected Vehicles". Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2895395.

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Arikatla, Jhansi R. "VIBRATIONS OF SERIES OF BEAMS CONNECTED BY FLEXIBLE NONLINEAR LAYERS WITH APPLICATION TO CARBON NANOTUBES". University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1164662552.

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15

Wu, Yiwei. "Connected Dominating Set Construction and Application in Wireless Sensor Networks". Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/cs_diss/45.

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Wireless sensor networks (WSNs) are now widely used in many applications. Connected Dominating Set (CDS) based routing which is one kind of hierarchical methods has received more attention to reduce routing overhead. The concept of k-connected m-dominating sets (kmCDS) is used to provide fault tolerance and routing flexibility. In this thesis, we first consider how to construct a CDS in WSNs. After that, centralized and distributed algorithms are proposed to construct a kmCDS. Moreover, we introduce some basic ideas of how to use CDS in other potential applications such as partial coverage and data dissemination in WSNs.

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16

Dabboussi, Abdallah. "Dependability approaches for mobile environment : Application on connected autonomous vehicles". Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCA029.

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Les véhicules autonomes et connectés (VAC) doivent avoir une exigence de fiabilité et de sécurité adéquate dans un environnement incertain aux circonstances complexes. La technologie des capteurs, les actionneurs et l'intelligence artificielle (IA) améliorent constamment leurs performances, ce qui permet un développement continu des véhicules autonomes et une automatisation accrue de la tâche de conduite. Les VAC présentent de nombreux avantages dans la vie humaine, tels que l’augmentation de la sécurité routière, la réduction de la pollution et la fourniture d’une mobilité autonome aux non-conducteurs. Cependant, ces composants avancés créent un nouvel ensemble de défis en matière de sécurité et de fiabilité. Il est donc nécessaire d’évaluer ces technologies avant leur mise en œuvre.Nous étudions dans cette thèse la fiabilité du VAC dans son ensemble, en nous concentrant sur les capteurs et le système de communication. Pour cela, une analyse fonctionnelle a été réalisée pour le système VAC. Notre approche scientifique pour l'analyse de la fiabilité du VAC a été structurée avec des méthodes combinant des approches quantitatives et qualitatives (telles que l'analyse fonctionnelle interne et externe, l'analyse préliminaire des risques (APR) et l'analyse des modes de défaillance, de leurs effets et de leur criticité (AMDEC), etc. Afin de prouver nos résultats, une simulation a été réalisée à l'aide de la probabilité d'analyse d'arbre de défaillance (ADD) et elle a été réalisée pour valider l'approche proposée. Les données (taux d'échec) utilisées proviennent d'une base de données professionnelle concernant le type de composants présentés dans le système. À partir de ces données, un modèle probabiliste de dégradation a été proposé. Le calcul de probabilité a été effectué par rapport à un moment d'utilisation de référence. Par la suite, une analyse de sensibilité a été suggérée concernant les paramètres de fiabilité et des propositions de restructuration ont été élaborées pour les composants.CAV fournit des services de communication entre véhicules : véhicules à véhicules (V2V) ou avec infrastructures côté rue : véhicules à infrastructures (V2I). La technologie des “Communications dédiées à courte portée” (DSRC = Dedicated Short Range Communications) utilise plusieurs canaux pour fournir une variété d'applications de sécurité. Les applications de sécurité nécessitent des transmissions appropriées et fiables, tandis que les applications non liées à la sécurité exigent des performances et une vitesse élevée. Aujourd’hui, la diffusion de messages de sécurité de base (Basic safety message, BSM) est l’un des services fondamentaux des véhicules connectés. Pour cela, un modèle analytique destiné à évaluer la fiabilité des services de diffusion V2V relatifs à la sécurité basée sur IEEE 802.11 dans le système DSRC sur autoroute a été proposé. Enfin, une amélioration du modèle proposé a été faite afin d'accroître la fiabilité de la connexion V2V, en tenant compte de nombreux facteurs tels que la portée de transmission, la densité du véhicule, la distance de sécurité sur l'autoroute, le taux d'erreur de paquets, l'influence de bruit et les taux de défaillants pour les équipements de communications.L'évaluation de ces problèmes conduit à une analyse de sensibilité liée aux paramètres de fiabilité, ce qui contribue à davantage d'innovation dans les domaines de l'ingénierie automobile
Connected and Autonomous vehicles (CAV) must have adequate reliability and safety requirements in uncertain environments with complex circumstances. Sensor technology, actuators and artificial intelligence (AI) are constantly and rapidly evolving, thus enabling further development of self-driving vehicles, and increasing the automation of driving. CAV shows many benefits in human life such as increasing road safety, reducing pollution, and providing independent mobility to non-drivers. However, these advanced components create a new set of challenges concerning safety and dependability. Hence, it is necessary to evaluate these technologies before implementation.We study in this thesis the reliability of CAV as a whole, focusing on sensors and the communication system. For that purpose, a functional analysis was done for the CAV system.Our scientific approach for the analyzing the CAV reliability, was structured with methods that combine quantitative and qualitative approaches such as functional analysis for both internal and external, Preliminary Risk Analysis (PRA), and failure modes and effects criticality analysis (FMECA), in addition to other analysis techniques.To prove our results, a simulation was done using the Fault Tree analysis (FTA) probability in order to validate the proposed approach. The data (Failure ratio) used were from a professional database related to the type of components presented in the system. Using this data, a probabilistic model of degradation was proposed. A probability calculation was performed in relation to a reference time of use. Thereafter a sensitivity analysis was suggested concerning the reliability parameters and redesign proposals developed for the components.CAV provide several communication models: vehicles to vehicle (V2V), or with Road Side Infrastructure: vehicle to infrastructure (V2I). Dedicated Short Range Communication (DSRC) employs a multichannel approach to cater for a variety of safety and non-safety applications. Safety applications necessitate appropriate and reliable transmissions, while non-safety applications require performance and high speed. Broadcasting of Basic Safety Messages (BSM) is one of the fundamental services in today’s connected vehicles. For that, an analytical model to evaluate the reliability of IEEE 802.11 based V2V safety-related broadcast services in DSRC system on highway was proposed. Finally, an enhancement on the proposed model was made in order to increase the reliability of the V2V connection, taking into consideration many factors such as transmission range, vehicle density, and safety headway distance on highway, packet error rate, noise influence, and failures rates of communication equipment.Evaluating these problems leads to a sensitivity analysis related to reliability parameters, which helps further innovation in CAV and automobile engineering

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17

Fyfe, Martin R. W. "Safety evaluation of connected vehicle applications using micro-simulation". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/59955.

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Connected vehicles are on the cutting edge of automotive technology with applications expected to improve mobility and safety. Several studies have evaluated the mobility benefits of connected vehicle technology but there is little research on its impact on safety. The first objective of this study is to investigate the ability to evaluate the safety of a connected vehicle applications using surrogate safety measures through a combination of the micro-simulation model VISSIM and the Surrogate Safety Assessment Model (SSAM). Two connected vehicle applications are reviewed, considering two types of connected vehicle communications, specifically Vehicle-to-Vehicle and Vehicle-to-Infrastructure. The two applications are a cumulative travel time (CTT) intersection control algorithm connected vehicle environment, and a cooperative adaptive cruise control (CACC) application, facilitating vehicle platooning on a freeway. The CACC study investigates the improvement to the freeway segment through a simulated incident. The CTT study investigates the impacts of calibrating the micro-simulation model using real-world vehicle trajectory and conflict data. The CTT algorithm is applied to a signalized intersection and evaluated under three calibration scenarios: uncalibrated, first step calibrated for desired speed and vehicle arrival types, and second step calibrated for conflicts observed in the field. In both studies, a comparison of safety based on the number of conflicts at different time-to-collision thresholds is provided for the varying scenarios. Results show that the combination of VISSIM and SSAM provide an appropriate tool to use in the evaluation of changes in the level of safety of connected vehicle applications, specifically the CACC application and the CTT intersection control application. Calibration of the micro-simulation model has a significant impact on the results of the safety evaluation. However, it is inconclusive whether the results are realistic with the lack of a real-world connected vehicle implementation.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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18

SERGI, FRANCESCO. "PEM fuel cell system analysis for grid connected applications". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1298.

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L'incremento delle sorgenti ad energia rinnovabile porterà un grande cambiamento sulla rete elettrica nazionale, la quale dovrà operare in modo intelligente per gestire la fornitura di molti produttori di energia distribuita e per compensare l'imprevedibilità delle rinnovabili. Tuttavia, per poter far ciò, le reti elettriche del futuro necessitano di generatori distribuiti capaci di assicurare servizi quali l'inseguimento del carico, l'accumulo di energia, la compensazione dei disturbi e che abbiano un effetto mitigante sui picchi di carico e/o di generazione. I sistemi a celle a combustibile, specialmente quelli alimentati ad idrogeno, hanno raggiunto considerevoli target in termini di prestazioni in condizioni di laboratorio. Combinando alta efficienza ed un comportamento dinamico veloce (disponibilità di potenza immediata su richiesta), anche a carichi parziali e con piccole taglie, i sistemi a cella a combustibile di tipo PEM sono sempre di più analizzati nell'ottica del loro impiego nelle nascenti reti di potenza. Lo scopo di questo lavoro è mostrare le attuali performance delle fuel cell, il loro comportamento durante il funzionamento con la rete elettrica ed, in particolare, i fenomeni relativi alla degradazione dei materiali che possono verificarsi in questo tipo di applicazioni. Dapprima l'attività di ricerca è stata indirizzata allo sviluppo di un sistema da 5 kW di tipo PEM, considerando le procedure di start up e di warm up, l'analisi del comportamento dinamico in funzione della variazione della temperatura e del carico elettrico. Conseguentemente, alcuni test sono stati condotti sia su sistemi che su monocella in modo da poter confrontare le prestazioni in caso di carichi in corrente continua ed alternata. Infatti, la potenza in reti monofase contiene una fluttuazione sinusoidale a bassa frequenza che procura un ripple sulla corrente di uscita dello stack. I test hanno mostrato la degradazione del materiale del catalizzatore dovuta a questo tipo di dinamica.
An increase in renewable energy sources (RWE) will bring about a great change in the national electric grid, which will operate intelligently (smart grid) in order to manage the supply of several energy producers and to cover the unpredictability of RWE [1]. Nevertheless, in order to become smart, the future electrical networks need active distributed units able to assure services like load following, back-up power, power quality disturbance compensation and peak shaving. Fuel cell systems, especially those fed with hydrogen, have reached considerable performance targets in laboratory conditions. Combining high efficiency and fast regulating behaviour (power on demand), even at partial loads and on small size units, PEM fuel cell systems are more and more investigated as components of the incoming power networks. The aim of this work is to highlight the fuel cells actual performances, their behaviour during grid connected operation and, particularly, the phenomena of materials degradation that can appear in these applications. At first, the research activity was addressed to the investigation on a developed 5 kW PEM fuel cell system, including the start-up and warm up procedure, the analysis of the dynamic behaviour linked to temperature and load variations. Accordingly, tests were conducted both on fuel cell systems and single cells in order to compare the performances evaluated with dc and ac loads. In fact, power drawn by single phase grids contains a low frequency sinusoidal fluctuation that brings a large ripple on the stack output current. The tests on single cells have determined the degradation occurred on catalyst material due to the effect of this kind of dynamic loads.

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19

Bessafa, Hichem. "Advanced Estimation Algorithms for Connected and Autonomous Vehicle Applications". Electronic Thesis or Diss., Université de Lorraine, 2024. http://www.theses.fr/2024LORR0075.

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Cette thèse est dédiée au développement d'algorithmes d'estimation avancés spécifiquement conçus pour les applications des véhicules autonomes. Initialement, nous fournissons un aperçu complet des différents contrôleurs de véhicules et des systèmes avancés d'assistance à la conduite, préparant le terrain pour une discussion approfondie sur les modèles de dynamique et de cinématique des véhicules. Nous explorons ensuite les observateurs classiques (basés sur des modèles) et ceux basés sur l'apprentissage automatique (pilotés par les données), en examinant leur littérature et leurs applications dans les contextes des véhicules et de la robotique. Notre recherche introduit plusieurs méthodologies novatrices : d'abord, une approche d'estimation sur un intervalle de temps fini pour les systèmes à paramètres variables linéaires (LPV) discrets, appliquée à la dynamique latérale du véhicule pour estimer le dérapage malgré les incertitudes de la rigidité en courbe. Ensuite, nous proposons un observateur neuro-adaptatif qui combine les réseaux neuronaux avec l'apprentissage concurrent pour estimer les forces inconnues dans le modèle longitudinal du véhicule. En outre, nous présentons un observateur généralisé à grand gain, incorporant des conditions de matrice linéairement inégalitaire (LMI) et une contrainte de seuil sur le paramètre de grand gain, conçu pour gérer des mesures et des contraintes supplémentaires. Cet observateur garantit des bornes de stabilité entrée-état (ISS) sur le bruit de mesure et s'adapte aux systèmes non canoniques via une transformation de sortie et une conception de système augmenté. Enfin, nous validons nos méthodes par des simulations étendues en utilisant le simulateur CARLA et l'estimation de trajectoire avec le jeu de données KITTI, démontrant une performance supérieure en termes de précision, de vitesse de convergence et de robustesse dans divers scénarios de véhicules. Les résultats illustrent des améliorations significatives par rapport aux méthodes traditionnelles, soulignant le potentiel pratique de nos techniques d'estimation avancées pour améliorer les performances des véhicules autonomes
This thesis is dedicated to the development of advanced estimation algorithms specifically designed for autonomous vehicle applications. Initially, we provide a comprehensive overview of various vehicle controllers and advanced driving assistance systems, setting the stage for an in-depth discussion of vehicle dynamics and kinematics models. We then explore both classical (model-based) and machine learning-based (data-driven) observers, examining their literature and applications within vehicular and robotics contexts. Our research introduces several novel methodologies: first, a finite time interval estimation approach for discrete Linear Parameter Varying (LPV) systems, applied to the vehicle's lateral dynamics to estimate side slip despite uncertainties in cornering stiffness. Next, we propose a neuro-adaptive observer that combines neural networks with concurrent learning to estimate unknown forces in the vehicle's longitudinal model. Furthermore, we present a generalized high-gain observer, incorporating Linear Matrix Inequality (LMI) conditions and a threshold constraint on the high-gain parameter, designed to handle additional measurements and constraints. This observer ensures Input-to-State Stability (ISS) bounds on measurement noise and adapts to non-canonical systems via output transformation and augmented system design. Finally, we validate our methods through extensive simulations using the CARLA simulator and trajectory estimation with the KITTI dataset, demonstrating superior performance in terms of accuracy, convergence speed, and robustness in various vehicular scenarios. The outcomes illustrate significant improvements over traditional methods, highlighting the practical potential of our advanced estimation techniques in enhancing autonomous vehicle performance

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20

Do, Tuan Anh. "Modélisation multiphysique des matériaux magnétoélectriques de seconde génération : application aux objets nomades connectés". Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS486.

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Les matériaux magnétoélectrique (ME) sont les matériaux composites fonctionnels composés de phases piézoélectriques et magnétostrictives qui a capacité de transformer l’énergie magnétique à l’énergie électrique par la médiation de l'énergie mécanique. L’effet ME peut être caractérisé en utilisant le coefficient magnétoélectrique (V/Oe). Cette propriété particulière génère un intérêt pour la recherche scientifique et plus particulièrement pour l’application de nouveaux transducteurs d’énergie, capteurs magnétiques ou inductances variables. Dans ce contexte, L2E a commencé depuis 2012 à développer des codes multiphysiques en éléments finis pour étudier les matériaux ME. Les travaux de cette thèse sont pour développer un modèle 3D combinant les modèles d'existence de piézoélectrique et magnétostrictif. Le modèle 3D est utilisé pour étudier le comportement du matériau magnétoélectrique: Modélisation de composite laminaire, prenant en compte la non linéarité de la magnétostrictive par un modèle multi-échelles et l'effet des courants de Foucault en régime dynamique ; Étude de différentes structures composites ME et de l'influence des paramètres géométriques sur la performance de ce matériau ; Application du principe d'homogénéisation à l'analyse du comportement magnétoélectrique de composites particules ME ou de composite fibres ME
Magnetoelectric materials (ME) are functional composite materials composed of piezoelectric and magnetostrictive phases that have the particularity of transforming magnetic energy into electrical energy through the mediation of mechanical energy. The ME effect can be characterized by a magnetoelectric coefficient (V/Oe). This particular property generates growing interests in the scientific research and more specifically in the application of new energy transducers, magnetic sensors or variable inductances. It is in this context that the L2E began since 2012 the development of multiphysics finite element codes to study the ME materials. This thesis is the development of a 3D model combining the existence models of piezoelectric and magnetostrictive for the investigation of ME behavior from three aspects: Modeling of laminate composite, taking into account the nonlinearity of magnetostrictive through a multiscale model and the effect of eddy currents in dynamic regime; Study of different ME composite structures and the influence of geometries parameters on the performance of this material; Application of the homogenization principle to analyze the magnetoelectric behavior of ME composites composed of granular nanoparticles type 0-3 or fiber composite type 1-3

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21

Wang, Yuan-Fang. "Computer Vision Analysis for Vehicular Safety Applications". International Foundation for Telemetering, 2015. http://hdl.handle.net/10150/596451.

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ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV
In this paper, we present our research on using computer-vision analysis for vehicular safety applications. Our research has potential applications for both autonomous vehicles and connected vehicles. In particular, for connected vehicles, we propose three image analysis algorithms that enhance the quality of a vehicle's on-board video before inter-vehicular information exchange takes place. For autonomous vehicles, we are investigating a visual analysis scheme for collision avoidance during back up and an algorithm for automated 3D map building. These algorithms are relevant to the telemetering domain as they involve determining the relative pose between a vehicle and other vehicles on the road, or between a vehicle and its 3D driving environment, or between a vehicle and obstacles surrounding the vehicle.

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22

PAREJO, MATOS ANTONIO. "Application of Intelligent Techniques for Optimal Management of Weakly Connected Microgrids". Doctoral thesis, Università degli studi di Genova, 2022. http://hdl.handle.net/11567/1081257.

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La decarbonizzazione e la mitigazione del cambiamento climatico sono diventate una priorità per molti Paesi e governi. Uno dei principali strumenti per realizzare questi obiettivi è la crescita delle fonti di generazione rinnovabili nel sistema elettrico, ma la loro inclusione costituisce una grande sfida per il funzionamento della rete a causa della loro alta variabilità e il loro comportamento stocastico. In questo contesto, la gestione del sistema elettrico e delle microgrid può essere trattata come un problema di ottimizzazione in cui le risorse vengono fatte funzionare con l'obiettivo di minimizzare la funzione di costo. Questa funzione di costo e le restrizioni operative corrispondenti dipendono da ogni situazione specifica, ad esempio, da quali sono i requisiti di consumo di energia, quanto è debole la connessione con la rete elettrica e quanto sono critici i carichi da alimentare nella zona. In questo senso, nonostante la grande varietà di approcci di ottimizzazione, questi hanno in comune l'importanza di contare su un sistema di previsione di alta qualità per prevedere le incertezze della microgrid (o rete) da far funzionare. I principali approcci esistenti per prevedere le incertezze sono la previsione deterministica e stocastica (che in molti casi è anche chiamata probabilistica). Considerando l'importanza dei sistemi di previsione per eseguire l'ottimizzazione delle microgrid e, in generale, delle reti elettriche, questa tesi di dottorato si concentra sulla progettazione di un modello di lavoro di previsione orientato alla microgrid che include una vasta gamma di approcci di previsione, che rende possibile la sua integrazione con altre applicazioni, ad esempio, sistemi di ottimizzazione della gestione dell'energia. Questo modello di lavoro include diversi metodi deterministici e stocastici ed è in grado di gestire l'addestramento e la selezione dei modelli per eseguire la previsione secondo il tipo di rappresentazione dell'incertezza che è richiesto in ogni caso.
The decarbonization and the climate change mitigation have become a priority for many countries and governments. One of the main tools for accomplishing these objectives is the growth of renewable generation sources in the power system, but their inclusion constitutes a great challenge for the network operation due to their high variability and their stochastic behavior. In this context, the management of the power system and microgrids can be treated as optimization problems in which the resources are operated with the aim of minimizing the cost function. This cost function and the corresponding operative restrictions depend on each specific situation, for example, on which are the power consumption requirements, how weak is the connection with the power grid, and how critical are the loads to be fed in the zone. In this sense, despite the large variety of optimization approaches, these have in common the importance of counting on a high-quality forecasting system for predicting the uncertainties of the microgrid (or network) to operate. The main existing approaches for predicting the uncertainties are deterministic and stochastic (which in many cases is also called probabilistic) forecasting. Considering the importance of forecasting systems for performing the optimization of microgrids and, in general, power networks, this doctoral thesis is focused on the design of a microgrid-oriented forecasting framework that includes a wide range of forecasting approaches, which makes possible its integration with other applications, for example, energy management optimization systems. This framework includes several deterministic and stochastic methods and is able to handle the training and selection of the models for performing the forecast according to the type of uncertainty representation that is required in each case.
La descarbonización y la reducción del cambio climático se han convertido en una prioridad para muchos países y gobiernos. Una de las principales herramientas para lograr estos objetivos es aumentar el número de fuentes de generación renovables en el sistema eléctrico, pero su inclusión constituye un gran reto debido a su alta variabilidad y su comportamiento estocástico. En este contexto, la gestión del sistema eléctrico y de las microrredes puede tratarse como problemas de optimización en los que los recursos se operan con el objetivo de minimizar la función de coste. Esta función de coste y las correspondientes restricciones operativas dependen de cada situación concreta, por ejemplo, de cuáles sean las necesidades de consumo de energía, de lo débil que sea la conexión con la red eléctrica y de lo críticas que sean las cargas a alimentar en la zona. En este sentido, a pesar de la gran variedad de enfoques de optimización, éstos tienen en común la importancia de contar con un sistema de predicción de alta calidad para predecir las incertidumbres de la microrred (o red) a optimizar. Los principales enfoques existentes para predecir las incertidumbres son la predicción determinista y la estocástica (que en muchos casos también se denomina probabilística). Teniendo en cuenta la importancia de los sistemas de predicción para realizar la optimización de las microrredes y, en general, de las redes eléctricas, esta tesis doctoral se centra en el diseño de un marco de trabajo para predicción orientado a las microrredes que incluye diversos enfoques para realizar la predicción, lo que hace posible su integración con otras aplicaciones como, por ejemplo, sistemas de optimización de gestión energética. Este marco de trabajo incluye varios métodos deterministas y estocásticos y es capaz de gestionar el entrenamiento y la selección de los modelos para realizar la predicción según el tipo de representación de la incertidumbre que se requiera en cada caso.

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23

Lef��vre, St��phanie. "Risk Estimation at Road Intersections for Connected Vehicle Safety Applications". Phd thesis, Universit�� de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00765930.

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Les intersections sont les zones les plus dangereuses du r��seau routier. Les ��tudes d'accidentologie montrent que la plupart des accidents aux intersections sont caus��s par des erreurs des conducteurs, et qu'une majorit�� d'accidents pourraient ��tre ��vit��s gr��ce �� l'utilisation de syst��mes d'aide �� la conduite. Dans ce cadre, les communications inter-v��hiculaire sont une technologie particuli��rement prometteuse. Le partage d'informations entre les v��hicules via des liens sans fil permet �� chaque v��hicule de percevoir son environnement au-del�� des limites de champ de vision de ses capteurs embarqu��s. Il en r��sulte une repr��sentation de l'environnement plus ��tendue dans l'espace et dans le temps, ce qui am��liore la compr��hension de situation et permet d'anticiper le danger. Cette th��se aborde le probl��me de l'estimation du risque sous un angle nouveau : elle propose une structure de raisonnement pour analyser les sc��nes routi��res et le risque de collision �� un niveau s��mantique, contrairement aux approches classiques qui raisonnent au niveau des trajectoires. Le risque est calcul�� en estimant les intentions des conducteurs et en d��tectant les conflits, sans avoir �� pr��dire les trajectoires futures des v��hicules. Plus pr��cis��ment, la d��tection des situations dangereuses est bas��e sur la comparaison entre ce que les conducteurs ont l'intention de faire et ce que les conducteurs devraient faire d'apr��s les r��gles de la circulation. Ce raisonnement est r��alis�� de mani��re probabiliste afin de prendre en compte les incertitudes sur les mesures capteur et les ambig��it��s sur l'interpr��tation de la sc��ne. En th��orie ce raisonnement peut ��tre appliqu�� tout type de sc��ne routi��re ; dans cette th��se nous pr��sentons son application aux intersections. Le mod��le propos�� prend en compte l'influence que la man��uvre d'un v��hicule exerce sur la man��uvre des autres v��hicules. Il incorpore aussi des informations sur l'influence de la g��om��trie et topologie de l'intersection sur le comportement d'un v��hicule. L'approche propos��e a ��t�� valid��e par des tests en environnement r��el avec des v��hicules communicants, ainsi qu'en simulation. Les r��sultats montrent que l'algorithme est capable de d��tecter les situations dangereuses et qu'il est compatible avec des applications s��curitaires temps-r��el.

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24

Klippenstien, J. "Applications of the universal coefficient theorem for connective k-theory". Thesis, University of Warwick, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371053.

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25

Carbillet, Thomas. "Monitoring en temps réel de la vitesse de déplacement sur dispositif connecté : modélisation mathématique sur plateforme mobile interfacée avec une base de données d'entraînement et d'audit physiologique". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAM013/document.

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L'amélioration de la performance en course à pied, lors de courses sur du plat, raisonne avec l'actualité et l'objectif de voir un athlète descendre en dessous des deux heures sur Marathon. Cependant, il existe peu d'équipes travaillant de façon transverse sur les sujets de préparation et de stratégie de course à destination du grand public. Les programmes d'entraînement, fondés sur l'expérience des entraîneurs, ne sont pas, ou peu, personnalisés ce qui conduit à des risques de blessures et une perte de la motivation. Une limite de l'analyse actuelle des programmes d'entraînement semble avoir été atteinte et l'entreprise BillaTraining® a pour objectif de construire un pont entre la recherche scientifique et les coureurs amateurs.L'objectif principal de ce travail de thèse est double. Premièrement, nous avons essayé d'apporter une contribution à la recherche dans le domaine de la course à pied. Après avoir accumulé et formaté des données d'entraînements et de courses provenant de différentes sources, nous avons cherché à décrire des phénomènes tels que l'accélération humaine ou encore les différentes stratégies de course employées sur Marathon pour des coureurs dont les performances de durée de course sont comprises entre 2h30 et 4 heures.Deuxièmement, nous avons développé une application web intégrant les trois phases de la méthode BillaTraining®. La première étape est un audit énergétique qui n'est autre qu'un entraînement de trente minutes à la sensation, permettant de connaitre les capacités physiques d'un coureur. La second étape, le radar énergétique, est le bilan de l'audit et agit comme point d'entrée de l'entraînement sur-mesure qui est la troisième et dernière étape.Afin de répondre à ces deux objectifs, nous avons intégré des notions de physiologie, de mathématiques et d'informatique.Les connaissances en physiologie sont basées sur l'état de l'art ainsi que les recherches passées et présentes du professeur Véronique Billat. Par extension, il s'agit du coeur de métier de l'entreprise BillaTraining®. Les idées de recherche présentent dans cette thèse émanent de la physiologie.Les mathématiques, quand à elles, nous ont permis de décrire certains phénomènes physiologiques grâce notamment aux statistiques. Nous avons eu l'occasion d'utiliser le modèle d'Ornstein-Uhlenbeck de retour à la moyenne ou encore la méthode PELT (Pruned Exact Linear Time) pour la détection d'instants de ruptures dans une série temporelle.Finalement, l'informatique permet de faire communiquer les mathématiques et la physiologie à des fins de recherche scientifique et commerciales
The improvement running performance has become a major topic lately. We are getting closer to running a marathon in under 2 hours. However, there are not so many professionals working transversally regarding pre-race and in-race preparation concerning the general public. Training plans are based on trainers' experience and are often not custom-made. This exposes the runners to injury risk and motivation loss. It seems that the current analysis of training plans has reached a limit. The aim for BillaTraining® is to go beyond this limit by connecting the research with the general public of runners.This PhD has two main goals. The first one is trying to contribute to the research about running. After gathering and formatting trainings and races data from different origins, we tried to isolate and describe how humans run marathons including 2.5 to 4-hour performances. We studied acceleration, speed and heart rate time series among other things, with the idea of understanding the different running strategies.The second one is the development of a web application embracing the three steps of the BillaTraining® method. The first step is an energetic audit which is a 30-minute running session guided by the runner's sensations. The second step is the energetic radar which is the results of the audit. The last step is a tailor-made training plan built depending on the runner's objectives.In order to come up with a solution, we had to bring together Physiology, Mathematics and Computer Science.The knowledge we had in Physiology was based on professor Véronique Billat's past and current researches. These researches are now part of BillaTraining® and are central for the growth of the company.We used Mathematics to try to describe physiological phenomenons thanks to Statistics. By applying the Ornstein-Uhlenbeck model, we found that humans are able to run at an even acceleration. By using the PELT (Pruned Exact Linear Time) method we automated changepoints detection in time series.Finally, Computer Science allowed a communication between Physiology and Mathematics for research, as well as marketing training tools at the forefront of innovation

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26

Danzfuss, Theodor Werner. "The technology of casually connected collaboration". Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-11232009-181958/.

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27

Afyouni, Soroosh. "Application of graph theoretical models to the functional connectome of human brain". Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/88528/.

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During the past decade, there has been a great interest in creating mathematical models to describe the properties of connectivity in the human brain. One of the established tools to describe these interactions among regions of the brain is graph theory. However, graph theoretical methods were mainly designed for the analysis of single network which is problematic for neuroscientists wishing to study groups of subjects. Specifically, studies using the Rich Club (RC) graph measure require cumbersome methods to make statistical inferences. In the first part of this work, we propose a framework to analyse the inter-subject variability in Rich Club organisation. The proposed framework is used to identify the changes in RC coefficient and RC organisation in patients with schizophrenia relative to healthy control. We follow this work by proposing a novel method, named Rich Block (RB), which is a combination of the tradition Rich Club and Stochastic Block Models (SBM). We show that using RBs can not only facilitate an inter-subject statistical inference, it can also account for differences in profile of connectivity, and control for subject-level covariates. We validate the Rich Block approach by simulating networks of different size and structure. We find that RB accurately estimates RC coefficients and RC organisations, specifically, in network with large number of nodes and blocks. With real data we use RB to identify changes in coefficient and organisation of highly connected sub-graphs of hub blocks in schizophrenia. In the final portion of this work, we examine the methods used to define each edge in networks formed from resting-state functional magnetic resonance imaging (rs-fMRI). The standard approach in rs-fMRI is to divide the brain into regions, extract time series, and compute the temporal correlation between each region. These correlations are assumed to follow standard results, when in fact serial autocorrelation in the time series can corrupt these results. While some authors have proposed corrections to account for autocorrelation, they are poorly documented and always assume homogeneity of autocorrelation over brain regions. Thus we propose a method to account for bias in interregion correlation estimates due to autocorrelation. We develop an exact method and an approximate, more computationally efficient method that adjusts for the sampling variability in the correlation coefficient. We use inter-subject scrambled real-data to validate the proposed methods under a null setting, and intact real-data to examine the impact of our method on graph theoretical measures. We find that the standard methods fail to practically correct the sensitivity and specificity level due to over-simplifying the temporal structure of BOLD time series, while even our approximate method is substantially more accurate.

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28

Allard, Denis. "Connecite des ensembles aleatoires : application a la simulation de reservoirs petroliers heterogenes". Paris, ENMP, 1993. http://www.theses.fr/1993ENMP0442.

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En geostatistique petroliere, la geometrie du facies permeable d'un reservoir petrolier est consideree comme une realisation d'un ensemble aleatoire. La connexite de deux modeles d'ensembles aleatoires couramment utilises - le modele gaussien seuille et le schema booleen - a ete etudiee a travers la probabilite de certains evenements typiques, comme par exemple l'existence d'un chemin reliant deux points. Apres avoir presente quelques resultats theoriques sur la connexite de ces modeles, on montre en utilisant des techniques de monte-carlo qu'il faut distinguer les caracteristiques de connexite locales des caracteristiques de connexite globales. Alors que les premieres dependent du modele simule et de la discretisation de la grille, les secondes ne dependent que du rapport entre la taille de la grille et la portee integrale du modele. On degage alors quelques regles pratiques qui permettent de faire correspondre le modele et les caracteristiques de connexite attendues. Dans le cadre du modele gaussien seuille, on presente ensuite un algorithme de simulation respectant des relations de connexite

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29

Marshall, Jonathan. "Function theory in multiply connected domains and applications to fluid dynamics". Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/1258.

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In this thesis we shall be considering a variety of problems set in the complex plane whose common feature is that they involve domains of finite multiple connectivity. We choose to focus on a particular canonical class of domains, namely circular domains. We extend our results to more general domains using conformal mappings. Results are derived for these circular domains by using the theory of Schottky groups. Problems we consider include the construction of automorphic functions, Green’s functions, and conformal mappings from circular domains to other commonly studied canonical domains. The abstract function-theoretic results we derive are applied to a number of physical problems of fluid dynamics

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30

Sharma, Ronald. "Single-phase transformerless unipolar switched inverters for utility-connected photovoltaic applications". University of Southern Queensland, Faculty of Engineering and Surveying, 2007. http://eprints.usq.edu.au/archive/00004120/.

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[Abstract]: The disadvantages of using solar energy are its capital cost (which is about A$6/W), in comparison to that of conventional sources of energy (which is about A$1.80/W), and its conversion efficiency, which in commercially available Photovoltaic (PV) systems is less than 20%. Consequently, for utility connected PV generation to become a viable alternative energy source, its efficiency needs to be improved, its cost reduced, and the quality of power supplied by the inverters must meet stringent standards.This dissertation describes the research work carried out to optimise the conversion efficiency and to minimise the cost of a single-phase, hysteretic current controlunipolar switched inverter system, for use as an interface between solar panels and the grid network. The 1 kW (peak power) PV system being considered does not useenergy storage batteries and the inverter output is connected to the grid supply without the use of a power transformer. Improvements in the efficiency of such aninverter system often come at the expense of the quality of its output power and an increase in cost. However, in the proposed inverter system the harmonics of theoutput current has been improved without compromising its overall efficiency or its cost. An improvement in power quality has been achieved using a novel AC splitinductorfilter network that reduces electromagnetic interference, prevents unwanted operation of the inverter switches, attenuates switching frequency harmonics,minimises low frequency harmonics and provides an average value of the inverter output current necessary for the removal of DC offset currents.An improvement in inverter efficiency and a reduction in cost has been achieved by omitting the 50 Hz power transformer (transformerless) and by optimising theinverter current control strategies. In Australia, some power supply authorities permit transformerless PV inverters of less than 10 kW rating to be connected to their supply system. However, avoiding the use of transformers can lead to magnitudes of DC offset current outside the limits specified by Australian Standard 4777.2, 2005 being injected into the grid supply. In this project a new cost effective DC offset current controller that removes DC offset current from the output of the inverter has been realised. This result translates into two primary benefits; firstly, a saving of about20% in the cost of the power transformer and in the cost of providing additional solar panels to overcome transformer power losses, and secondly the DC offset controller can also be utilised in inverter applications where power transformers are used, to prevent distortion of the magnetising current.The novel design procedure proposed in this thesis for a current controller takes into account intentional and unintentional switching circuit delays, and yields higherefficiencies without sacrificing power quality or increasing the cost of the inverter system. The inclusion of the effect of circuit delays in the design procedure issignificant as it is shown that delay not only has an adverse effect on the performance of the current controller but also on the efficiency and the power quality of the inverter system.Of paramount importance for the successful completion of this project was the relationship between switching circuit delays and the level of low frequencyharmonics generated by unipolar switched inverters. Theoretical analysis is developed to show why circuit delays, inverter DC input voltage and the inductanceof the current loop, are responsible for low frequency harmonics in unipolar switched and not in bipolar switched inverters. It has also been established that unipolarswitched inverters can be designed to operate within the limits specified by the Australian Standard 4777.2, 2005 and that the low frequency harmonics can be maintained at acceptable levels.For a current controller using unipolar switching, the choice of only one of four equivalent switching combinations of the inverter switches leads to suppression of switching noise, and prevents unwanted switching without the need for additional filters. Results are presented to demonstrate the unique advantage of unipolarswitching over bipolar switching.

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31

Nachit, Oussama. "Mieux comprendre l'EXPansion et l'EXTension de soi du consommateur : une application à un objet connecté". Electronic Thesis or Diss., Université de Montpellier (2022-....), 2024. http://www.theses.fr/2024UMOND008.

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Dans un monde technologiquement avancé où les objets connectés deviennent une partie de notre identité personnelle, cette thèse examine les relations entre les individus et leur montre connectée à travers les prismes de l'EXPansion de soi (Aron et Aron, 1986) et de l'EXTension de soi (Belk, 1988). Cette recherche met en lumière la manière complexe et riche dont les individus intègrent ces dispositifs dans leur conception de soi, modulant ainsi leur attachement et leur intention de poursuivre l'utilisation de ces technologies. Ainsi, la problématique de ce travail doctoral s'articule comme suit : « Quelles sont les relations entretenues par les individus avec leur montre connectée via l'EXPansion et l'EXTension de soi, et l'impact de ces dernières sur l'attachement et la continuité d'utilisation de ces montres ? » Cette question a conduit à une enquête structurée autour de quatre questions de recherche spécifiques qui cherchent à explorer les manifestations de ces processus psychologiques dans le cadre des interactions avec une montre connectée. Cette recherche adopte une approche mixte, combinant des analyses qualitatives pour détailler les expériences des utilisateurs avec leurs montres connectées, suivies de deux études quantitatives pour mesurer l'impact des motivations d'achat et des attributs de la montre sur l'EXPansion et l'EXTension de soi. Les méthodes employées ont permis de valider les relations hypothétiques entre les construits théoriques et les comportements des utilisateurs. Les résultats révèlent que les montres connectées sont perçues non seulement comme des outils fonctionnels mais aussi comme des éléments essentiels de l'identité des utilisateurs. Les résultats montrent que les motivations d'achat agentiques et les attributs de la montre impactent directement l'EXPansion de soi, qui à son tour facilite l'EXTension de soi, menant à un plus grand attachement et une intention renforcée de continuer à utiliser la montre. Ces résultats soulignent la séquentialité des processus d'EXPansion et d'EXTension de soi dans la formation de l'attachement aux objets connectés. Les implications de cette recherche sont significatives pour les fabricants de montres connectées, et les apports théoriques multiples s'inscrivent dans la littérature portant sur l'EXPansion et L'EXTension de soi. La thèse reconnaît les limites liées à la focalisation sur les montres connectées et suggère d'élargir l'analyse à d'autres technologies portables pour examiner si les découvertes se généralisent à d'autres dispositifs
In a technologically advanced world where connected objects become a part of our personal identity, this thesis examines the relationships between individuals and their smartwatches through the prisms of self-EXPansion (Aron and Aron, 1986) and self-EXTension (Belk, 1988). This research highlights the complex and rich manner in which individuals integrate these devices into their self-concept, thus modulating their attachment and intention to continue using these technologies. Therefore, the central problem of this doctoral work is articulated as follows: "What are the relationships maintained by individuals with their smartwatch via self-EXPansion and self-EXTension, and the impact of these processes on the attachment and continued use of these watches?" This question led to a structured investigation around four specific research questions that seek to explore the manifestations of these psychological processes in the context of interactions with a smartwatch.This research adopts a mixed-methods approach, combining qualitative analyses to detail the experiences of users with their smartwatches, followed by two quantitative studies to measure the impact of purchase motivations and watch attributes on self-EXPansion and self-EXTension. The methods used validated the hypothetical relationships between the theoretical constructs and user behaviors. The findings reveal that smartwatches are perceived not only as functional tools but also as essential elements of the users' identity. The results show that agentic purchase motivations and the attributes of the watch directly impact self-EXPansion, which in turn facilitates self-EXTension, leading to greater attachment and a reinforced intention to continue using the watch. These results underscore the sequentiality of the self-EXPansion and self-EXTension processes in the formation of attachment to connected objects.The implications of this research are significant for manufacturers of smartwatches, and the multiple theoretical contributions fit into the literature on self-EXPansion and self-EXTension.The thesis acknowledges the limitations related to the focus on smartwatches and suggests broadening the analysis to other wearable technologies to examine whether the findings generalize to other devices

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Öhrström, Tobias y Christoffer Olsson. "The precision of RSSI-fingerprinting based on connected Wi-Fi devices". Thesis, Högskolan i Borås, Akademin för bibliotek, information, pedagogik och IT, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-12161.

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Received Signal Strength Indication (RSSI) fingerprinting is a popular technique in the fieldof indoor positioning. Many studies on the subject exist acknowledging Wi-Fi signal variationconnected to Wi-Fi signals, but does not discuss possible signal variation created byconnected devices nor consequential precision loss.Understanding more about the origins of signal variation in received signal strength indication(RSSI) fingerprinting would help deal with or prevent them as well as provide moreknowledge for applications based on such signals. Environments with a varying number ofconnected devices would benefit from knowing changes in localization precision resultingfrom the devices connecting and disconnecting from the access point because it wouldindicate whether workarounds for such circumstances would be necessary.To address this issue, the work presented here focuses on how the precision of RSSIfingerprinting vary given different levels of connected Wi-Fi devices. It was carried out byconducting real world experiments at times of low- and normal levels of connected devices toaccess points on two separate locations and evaluating precision changes between statedactivity levels. These experiments took place at the University of Borås as well as at Ericssonin Borås.Experimental findings indicate that the accuracy does deteriorate in higher levels of activitythan in low activity, even though not enough evidence to determine the precision ofdeterioration. The experiments thereby provide a foundation for location-based applicationsand services that can communicate the level of positional error that exist in differentenvironments which would make the users aware but also make the applications adaptaccordingly to different environments. Based on the precision achieved, we identify variousapplications that would benefit from our proposed model. These were applications that wouldtrack mobile resources, find immobile resources, find the movement flows of users as well asnavigation- and Wi-Fi coverage applications.Further research for investigating the exact correlation between access point stress andprecision loss is proposed to fully understand the implications connected devices have onRSSI fingerprinting.

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Du, Yang. "Modeling and analysis of single-phase two-stage inverter for grid-connected photovoltaic application". Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9334.

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In order to extract the maximum amount of power from the PV modules and convert it into an appropriate form for grid integration, a power electronics interface is needed. This thesis focuses on analysis and modeling of the single-phase two-stage inverter for grid-connected PV application with special attention given to the harmonic issues. A DC/DC battery-integrated boost converter can serve as the front end in a two-stage PV inverter configuration. A steady-state analysis for this new type of converter is carried out. An application of this converter in distributed Maximum Power Point Tracking (MPPT) architecture is proposed and compared with the conventional boost converter. By adding energy storage devices, it has the potential to compensate for the intermittent attribute of the PV generators. It also yields a more stabilized DC-link voltage in the distributed MPPT application. This thesis also analyzes the harmonic distortions generated from a PV inverter, which mainly relate to the DC/AC stage of the PV inverter. The field measurements are carried out at the CSIRO micro-grid. The high total harmonic distortion phenomenon is found when the PV inverters operate at light load condition. The conventional model of a PV inverter does not contain any harmonic information. A linear model for the PV inverter is modified to analyze the harmonic formation process. The causes of harmonics are summarized for the PV inverter operating at different power levels. The constant DC-link voltage assumption is not necessarily true for the two-stage PV inverter. The model of the grid-connected PV inverter with feedback control becomes time-varying with consideration for the DC-link voltage ripple. A series of odd harmonics is identified to be caused by this double-line frequency DC-link voltage ripple. The transfer function cannot be derived for this model. It is a challenge to calculate the exact harmonic amplitudes. The closed-form solution for this time-varying model is derived based on an idea which is similar to the harmonic balance method. A guideline is provided to select the minimum size of capacitor for the DC-link without sacrificing the power quality. Simulation and experimental results are provided to verify the aforementioned analysis results. In addition, some suggestions for future work are given.

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Rao, Narasimha D. (Narasimha Desirazu). "A capacity planning methodology for rural India : an application to grid-connected photovoltaics". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38766.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.
Includes bibliographical references (leaves 111-113).
by Narasimha D. Rao.
M.S.

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35

Hussain, Saed. "Fault tolerant flight control : an application of the fully connected cascade neural network". Thesis, University of Central Lancashire, 2015. http://clok.uclan.ac.uk/12123/.

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The endurance of an aircraft can be increased in the presence of failures by utilising flight control systems that are tolerant to failures. Such systems are known as fault tolerant flight control systems (FTFCS). FTFCS can be implemented by developing failure detection, identification and accommodation (FDIA) schemes. Two of the major types of failures in an aircraft system are the sensor and actuator failures. In this research, a sensor failure detection, identification and accommodation (SFDIA); and an actuator failure detection, identification and accommodation (AFDIA) schemes are developed. These schemes are developed using the artificial neural network (ANN). A number of techniques can be found in the literature that address FDIA in aircraft systems. These techniques are, for example, Kalman filters, fuzzy logic and ANN. This research uses the fully connected cascade (FCC) neural network (NN) for the development of the SFDIA and AFDIA schemes. Based on the study presented in the literature, this NN architecture is compact and efficient in comparison to the multi-layer perceptron (MLP) NN, which is a popular choice for NN applications. This is the first reported instance of the use of the FCC NN for fault tolerance applications, especially in the aerospace domain. For this research, the X-Plane 9 flight simulator is used for data collection and as a test bed. This simulator is well known for its realistic simulations and is certified by the Federal Aviation Administration (FAA) for pilot training. The developed SFDIA scheme adds endurance to an aircraft in the presence of failures in the aircraft pitch, roll and yaw rate gyro sensors. The SFDIA scheme is able to replace a faulty gyro sensor with a FCC NN based estimate, with as few as 2 neurons. In total, 105 failure experiments were conducted, out of which only 1 went undetected. In the developed AFDIA scheme, a FCC NN based roll controller is employed, which uses just 5 neurons. This controller can adapt on-line to the post failure dynamics of the aircraft following a 66\% loss of wing surface. With 66\% of the wing surface missing, the NN based roll controller is able to maintain flight. This is a remarkable display of endurance by the AFDIA scheme, following such a severe failure. The results presented in this research validate the use of FCC NNs for SFDIA and AFDIA applications.

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Lane, Emily M. "Wave-current interactions in coastal waters and their application to shore-connected bars". Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280520.

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A multi-scale asymptotic theory is derived for the evolution and interaction of currents and surface gravity waves in water of finite depth, under conditions typical of coastal shelf waters outside the surf zone. The theory provides a practical and useful model with which wave-current coupling may be explored without the necessity of resolving features of the flow on space and time scales of the primary gravity-wave oscillations. The essential nature of the dynamical interaction is currents modulating the slowly evolving phase of the wave field and waves providing both phase-averaged forcing of long, infra-gravity waves and wave-averaged vortex forces for the low-frequency current and sea-level evolution equations. Analogous relations are derived for material tracers and density stratification that include phase-averaged, Stokes-drift advection, including by a vertical Stokes pseudo-velocity that is the incompressible companion to the horizontal Stokes velocity. This theory is used to study the effect of waves on the evolution of large-scale erodible beds. In particular, the formation of certain up-current rotated, shore-connected bars is investigated. It is hypothesized that these bars form due to an instability of the bottom topography in the presence of a storm driven flow. This hypothesis is reviewed in the light of the presence of both waves and currents. It is shown that waves can significantly affect the instability. The effects of different wave parameters are investigated. Steady flow and boundary condition assumptions are also examined.

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37

White, James Angus. "Development and evaluation of a socially connected mobile application to increase fish consumption". Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/1925.

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Fish consumption is protective against many chronic diseases. A complex intervention approach was used to guide formative research, identifying barriers to consumption. This in turn guided the development of a socially connected mobile application that was evaluated in an exploratory trial. While overall fish consumption did not differ significantly between intervention and control groups, some patterns of application use were associated with increased consumption. Implications are discussed for the development and evaluation of mHealth interventions.

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Kristiansson, Johan. "Creating always-best-connected multimedia applications for the 4th generation wireless systems /". Luleå, 2004. http://epubl.luth.se/1402-1757/2004/40.

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Srinivas, Shirish. "Free Vibrations of Elastically Connected Stretched Beams with Applications To Carbon Nanotubes". University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1226671765.

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40

Sonklin, Kachane. "Studies of communication and positioning performance of connected vehicles for safety applications". Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/207089/1/Kachane_Sonklin_Thesis.pdf.

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Connected vehicles for safety applications play a significant role on reduction of the risks of road accidents. However, the performance of communication and positioning approaches is a major concern. This thesis establishes a connectivity framework based on publish-subscribe architecture for high-timeliness vehicle-to-vehicle data exchanges and determines the performance requirements for precise vehicle positioning for various safety use cases. Extensive experimental results demonstrated the performance benefits of the communication and positioning solutions for vehicle safety applications.

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41

Riffonneau, Yann. "Gestion des flux énergétiques dans un système photovoltaïque avec stockage connecté au réseau : application à l'habitat". Grenoble 1, 2009. http://www.theses.fr/2009GRE10206.

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Ces travaux de thèse constituent une contribution à l'introduction massive de la production photovoltaïque (PV) sur le réseau électrique. L'énergie PV possède un potentiel immense, notamment dans le secteur de l'habitat, mais l'effet d'intermittence limite son développement à grande échelle. Dans cette thèse nous proposons d'ajouter un élément de stockage aux systèmes photovoltaïques connectés au réseau dans l'habitat. Nous commençons par introduire la notion de gestion d'énergie dans ces systèmes dits « hybrides », dont l'objectif qui a été fixé est de réduire les pics de puissance appelée, voire produite. Ensuite, nous proposons et étudions des stratégies de gestion optimisées d'énergie basées sur des données prévisionnelles d'irradiations, de températures ambiante, de consommation et des prix de l'énergie. Enfin, nous apportons des solutions théoriques originales de gestion en temps réel, notamment en introduisant des réponses au problème des incertitudes sur les prévisions
The work done during this thesis contributes to the intensive penetration of the photovoltaic electricity production into the electric grid. Photovoltaic energy holds an immense potential, in particular in the housing sector, but intermittent nature limits its large scale development. In this thesis, we propose to add a storage element to the grid connected photovoltaic system (housing application). First, we introduce the notion of energy management in these systems called « hybrids systems ». The objective is to reduce the peak power consumption and production. Next, we propose and study optimized energy strategies based on predictive indications of irradiation, ambient temperature, power consumption and electricity grid prices. Finally, we bring theoretical solutions to the real time energy management, notably by proposing a solution to the problem of prediction uncertainty

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42

Bouyedda, Abdellatif. "Optimisation de la chaîne de transmission radio en bande ISM pour des applications IoT, notamment en agriculture connectée". Electronic Thesis or Diss., Limoges, 2024. http://www.theses.fr/2024LIMO0116.

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Cette thèse a examiné des solutions innovantes pour optimiser la connectivité et les performances des objets connectés, en mettant particulièrement l'accent sur l'agriculture connectée, où garantir la connectivité est crucial. En analysant les technologies LPWAN et satellitaires, nous avons démontré que la connectivité hybride constitue une approche prometteuse pour couvrir les zones blanches, notamment dans des régions rurales isolées. Un prototype d’antenne pour la communication par satellite a été conçu pour assurer une réception efficace avec la constellation Kinéis, tandis qu'une antenne reconfigurable en fréquence a été développée pour faciliter des communications flexibles entre les réseaux terrestres et satellites. De plus, l'amélioration d'un système TPMS, spécifiquement destiné aux engins agricoles, a permis d'accroître la sensibilité et la robustesse du système, répondant ainsi aux exigences des applications dans des environnements difficiles. Malgré certains défis liés à la complexité de fabrication, cette recherche jette des bases solides pour des solutions IoT adaptées aux besoins spécifiques de l’agriculture connectée et ouvre des perspectives pour d'autres secteurs nécessitant une couverture dans des zones reculées
This thesis examined innovative solutions to optimize the connectivity and performance of connected objects, particularly focusing on connected agriculture, where ensuring connectivity is crucial. By analyzing LPWAN and satellite technologies, we demonstrated that hybrid connectivity represents a promising approach to covering white zones, especially in isolated rural areas. A satellite communication antenna prototype was designed to ensure effective reception with the Kinéis constellation, while a frequency-reconfigurable antenna was developed to facilitate flexible communications between terrestrial and satellite networks. Additionally, the enhancement of a TPMS system, specifically aimed at agricultural machinery, significantly increased the sensitivity and robustness of the system, thus meeting the requirements of applications in challenging environments. Despite certain challenges related to manufacturing complexity, this research lays a solid foundation for IoT solutions tailored to the specific needs of connected agriculture and opens perspectives for other sectors requiring coverage in remote areas

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43

Stiefenhofer, Pascal Christian. "Stability analysis of non-smooth dynamical systems with an application to biomechanics". Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61481/.

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This thesis discusses a two dimensional non-smooth dynamical system described by an autonomous ordinary differential equation. The right hand side of the differential equation is assumed to be discontinuous. We provide a local theory of existence, uniqueness and exponential asymptotic stability and state a formula for the basin of attraction. Our conditions are sufficient. Thetheory generalizes smooth dynamical systems theory by providing contraction conditions for two nearby trajectories at a jump. Such conditions have only previously been studied for a two dimensional nonautonomous differential equation. We provide an example of the theory developed in this thesis and show that we can determine stability of a periodic orbit without explicitly calculating it. This is the main advantage of our theory. Our conditions require to define a metric. This however, can turn out to be a difficult task, and at present, we do not have a method for finding such a metric systematically. The final part of this thesis considers an application of a nonsmooth dynamical system to biomechanics. We model an elderly person stepping over an obstacle. Our model assumes stiff legs, and suggests a gait strategy to overcome an obstacle. This work is in collaboration with Professor Wagner's research group at Institute for Sport Science at the University of Mϋnster. However, we only present work developed independently in this thesis.

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44

Solano, Araque Edwin. "De l’ergonomie automobile à l’optimisation de la conduite automatisée. Application à l’écoconduite des véhicules électriques". Thesis, Orléans, 2020. http://www.theses.fr/2020ORLE3059.

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Cette thèse se focalise sur l'étude de l’écoconduite (pratique de conduite visant à réduire l’impact environnemental de l’utilisation du véhicule) et, en particulier, des éco-manœuvres de conduite, avec prise en compte des contraintes d'infrastructure et de trafic, ainsi que des contraintes d'agrément de conduite. De plus, nous considérons, lors de la conception de l'algorithme, des principes inspirés de la cognition humaine, afin de renforcer l'efficacité et la bonne modularité. La facilité de calibration de l'algorithme est un autre aspect pris en considération. L'ensemble de l'exposé se focalise sur les véhicules électriques à batterie. Cependant, les principes proposés peuvent être adaptés pour leur application sur d'autres types de groupe motopropulseur.Ces travaux s’orientent sur trois grandes lignes. La première, l'Ergonomie de conduite, a permis de déterminer des critères d'agrément de conduite ; une modélisation du conducteur permettant de tenir compte des aspects ergonomiques est proposée. De même, nos hypothèses sont confrontées au comportement d’un conducteur en situation réelle, en appliquant une méthodologie innovante pour l'analyse d'enregistrements de roulages réels. Ensuite, une Modélisation énergétique du véhicule et des manœuvres de conduite est présentée, ainsi qu'une analyse du potentiel et l’origine du gain associé à différentes stratégies d'éco-conduite. Finalement un Algorithme de commande est proposé pour la réalisation d'éco-manœuvres de conduite, avec prise en compte des critères d'agrément. La structure globale de l'algorithme, basée sur les principes cognitifs, est constitué de plusieurs sous-systèmes le rendant modulaire et capable de répondre aux contraintes de calcul en temps réel et de mise au point, propres au milieu industriel
In the framework of this dissertation, we will focus on Eco-driving and, particularly on eco-maneuvers, taking into account constraints associated to infrastructure and traffic, as well as with drivability. Additionally, we will take inspiration on Cognitive Principles for the algorithm design; it will allow to reinforce algorithm’s effectiveness and modularity. Easiness of calibration will also be an important concern for our work. Our whole discussion focuses on Battery Electric Vehicles. However, the proposed principles may be adapted for their application for other types of powertrain.Our work treats three main topics: on one side, Driving Ergonomics, allowing to determine some criteria on drivability ; we will also propose a modelling of the driver allowing to take into account ergonomics considerations. Finally, we will assess our hypothesis with respect with driver behavior on real situations, by applying an innovative methodology for the analysis of actual driving records. Next we will focus on Energy Model of the vehicle and of driving maneuvers, as well as to the assessment of energy gain potential associated to several Eco-driving strategies; the origin of these gains is also studied. Finally, we propose a Control Algorithm allowing to execute driving eco-maneuvers, while taking into account drivability criteria. The global algorithm structure is based on cognitive principles presented earlier. These function consists of several subsystems, which improves its modularity, and enforces its potential to operate within real-time constraints, and simplifies calibrations ; these both are major advantages for an industrial application

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45

Ohn, Sungjae. "Circuits and Modulation Schemes to Achieve High Power-Density in SiC Grid-connected Converters". Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/89550.

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The emergence of silicon-carbide (SiC) devices has been a 'game changer' in the field of power electronics. With desirable material properties such as low-loss characteristics, high blocking voltage, and high junction temperature operation, they are expected to drastically increase the power density of power electronics systems. Recent state-of-the-art designs show the power density over 17 ; however, certain factors limit the power density to increase beyond this limit. In this dissertation, three key factors are selected to increase the power density of SiC-based grid-connected three-phase converters. Throughout this dissertation, the techniques and strategies to increase the power density of SiC three-phase converters were investigated. Firstly, a magnetic integration method was introduced for the coupled inductors in the interleaved three-phase converters. Due to limited current-capacity compared to the silicon insulated-gate bipolar transistors (Si-IGBTs), discrete SiC devices or SiC modules, operate in parallel to handle a large current. When three-phase inverters are paralleled, interleaving can be used, and coupled inductors are employed to limit the circulating current. In Chapter 2, the conventional integration method was extended to integrate three coupled inductors into two; one for differential-mode circulating current and the other for common-mode circulating current. By comparing with prior research work, a 20% reduction in size and weight is demonstrated. From Chapter 3 to Chapter 5, a full-SiC uninterruptible power supply (UPS) was investigated. With the high switching frequency and fast switching dynamics of SiC devices, strategies on electromagnetic inference become more important, compared to Si-IGBT based inverters. Chapter 3 focuses on a common-mode equivalent circuit model for a topology and pulse width modulation (PWM) scheme selection, to set a noise mitigation strategy in the design phase. A three terminal common-mode electromagnetic interference (EMI) model is proposed, which predicts the impact of the dc-dc stage and a large battery-rack on the output CM noise. Based on the model, severe deterioration of noise by the dc-dc stage and battery-rack can be predicted. Special attention was paid on the selection of the dc-dc stage's topology and the PWM scheme to minimize the impact. With the mitigation strategy, a maximum 16 dB reduction on CM EMI can be achieved for a wide frequency range. In Chapter 4, an active PWM scheme for a full-SiC three-level back-to-back converter was proposed. The PWM scheme targets the size reduction of two key components: dc-link capacitors and a common-mode EMI filter. The increase in switching frequency calls for a large common-mode EMI filter, and dc-link capacitors in the three-level topology may take a considerable portion in the total volume. To reduce the common-mode noise emission, different combinations of the voltage vectors are investigated to generate center-aligned single pulse common-mode voltage. By such an alignment of common-mode voltage with different vector combinations, noise cancellation between the rectifier and the inverter can be maximally utilized, while the balancing of neutral point voltage can be achieved by the transition between the combinations. Also, to reduce the size of the dc-link capacitor for the three-level back-to-back converter, a compensation algorithm for neutral point voltage unbalance was developed for both differential-mode voltage and the common-mode voltage of the ac-ac stage. The experimental results show a 4 dB reduction on CM EMI, which leads to a 30% reduction on the required CM inductance value. When a 10% variation of neutral point voltage can be handled, the dc-link capacitance can be reduced by 56%. In Chapter 5, a 20 kW full-SiC UPS prototype was built to demonstrate a possible size-reduction with the proposed PWM scheme, as well as a selection of topologies and PWM schemes based on the model. The power density and efficiency are compared with the state-of-the-art Si-IGBT based UPSs. Chapter 6 seeks to improve power density by a change in a modulation method. Triangular conduction mode (TCM) operation of the three-level full-SiC inverter was investigated. The switching loss of SiC devices is reported to be concentrated on the turn-on instant. With zero-voltage turn-on of all switches, the switching frequency of a three-level three-phase SiC inverter can be drastically increased, compared to the hard-switching operation. This contributes to the size-reduction of the filter inductors and EMI filters. Based on the design to achieve a 99% peak efficiency, a comparison was made with a full-SiC three-level inverter, operating in continuous conduction mode (CCM), to verify the benefit of the soft switching scheme on the power density. A design procedure for an LCL filter of paralleled TCM inverters was developed. With 3.5 times high switching frequency, the total weight of the filter stage of the TCM inverter can be reduced by 15%, compared to that of the CCM inverter. Throughout this dissertation, techniques for size reduction of key components are introduced, including coupled inductors in parallel inverters, an EMI filter, dc-link capacitors, and the main boost inductor. From Chapter 2 to 5, the physical size or required value of these key components could be reduced by 20% to 56% by different schemes such as magnetic integration, EMI mitigation strategy through modeling, and an active PWM scheme. An optimization result for a full-SiC UPS showed a 40% decrease in the total volume, compared to the state-of-the-art Si-IGBT solution. Soft-switching modulation for SiC-based three-phase inverters can bring a significant increase in the switching frequency and has the potential to enhance power-density notably. A three-level three-phase full-SiC 40 kW PV inverter with TCM operation contributed to a 15% reduction on the filter weight.
Doctor of Philosophy
The power density of a power electronics system is regarded as an indicator of technological advances. The higher the power density of the power supply, the more power it can generate with the given volume and weight. The size requirement on power electronics has been driven towards tighter limits, as the dependency on electric energy increases with the electrification of transportation and the emergence of grid-connected renewable energy sources. However, the efficiency of a power electronics system is an essential factor and is regarded as a trade-off with the power density. The size of power electronics systems is largely impacted by its magnetic components for filtering, as well as its cooling system, such as a heatsink. Once the switching frequency of power semiconductors is increased to lower the burden on filtering, more loss is generated from filters and semiconductors, thus enlarging the size of the cooling system. Therefore, considering the efficiency has to be maintained at a reasonable value, the power density of Si-based converters appears to be saturated. With the emergence of wide-bandgap devices such as silicon carbide (SiC) or gallium nitride (GaN), the switching frequency of power devices can be significantly increased. This is a result of superior material properties, compared to Si-based power semiconductors. For grid-connected applications, SiC devices are adopted, due to the limitations of voltage ratings in GaN devices. Before commercial SiC devices were available, the power density of SiC- based three-phase inverters was expected to go over 20 𝑘𝑊 𝑑𝑚3 ⁄ . However, the state-of-the art designs shows the power density around 3 ~ 4 𝑘𝑊 𝑑𝑚3 ⁄ , and at most 17 𝑘𝑊 𝑑𝑚3 ⁄ . The SiC devices could increase the power density, but they have not reached the level expected. The adoption of SiC devices with faster switching was not a panacea for power density improvement. This dissertation starts with an analysis of the factors that prevent power density improvement of SiC-based, grid-connected, three-phase inverters. Three factors were identified: a limited increase in the switching frequency, large high-frequency noise generation to be filtered, and smaller but still significant magnetic components. Using a generic design procedure for three-phase inverters, each chapter seeks to frame a strategy and develop techniques to enhance the power density. For smaller magnetic components, a magnetic integration scheme is proposed for paralleled ac-dc converters. To reduce the size of the noise filter, an accurate modeling approach was taken to predict the noise phenomena during the design phase. Also, a modulation scheme to minimize the noise generation of the ac-ac stage is proposed. The validity of the proposed technique was verified by a full-SiC three-phase uninterruptible power supply with optimized hardware design. Lastly, the benefit of soft-switching modulation, which leads to a significant increase in switching frequency, was analyzed. The hardware optimization procedure was developed and compared to hard-switched three-phase inverters.

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46

Taylor, Michael. "Exact and approximate epidemic models on networks : theory and applications". Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/45258/.

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This thesis is concerned with modelling the spread of diseases amongst host populations and the epidemics that result from this process. We are primarily interested in how networks can be used to model the various heterogeneities observable in real-world populations. Firstly, we start with the full system of Kolmogorov/master equations for a simple Susceptible-Infected-Susceptible (SIS) type epidemic on an arbitrary contact network. From this general framework, we rigorously derive sets of ODEs that describe the exact dynamics of the expected number of individuals and pairs of individuals. We proceed to use moment closure techniques to close these hierarchical systems of ODEs, by approximating higher order moments in terms of lower order moments. We prove that the simple first order mean-field approximation becomes exact in the limit of a large, fully-connected network. We then investigate how well two different pairwise approximations capture the topological features of theoretical networks generated using different algorithms. We then introduce the effective degree modelling framework and propose a model for SIS epidemics on dynamic contact networks by accounting for random link activation and deletion. We show that results from the resulting set of ODEs agrees well with results from stochastic simulations, both in describing the evolution of the network and the disease. Furthermore, we derive an analytic calculation of the stability of the disease-free steady state and explore the validity of such a measure in the context of a dynamically evolving contact network. Finally, we move on to derive a system of ODEs that describes the interacting dynamics of a disease and information relating to the disease. We allow individuals to become responsive in light of received information and, thus, reduce the rate at which they become infected. We consider the effectiveness of different routes of information transmission (such as peer-to-peer communication or mass media campaigns) in slowing or preventing the spread of a disease. Finally, we use a range of modelling techniques to investigate the spread of disease within sheep flocks. We use field data to construct weighted contact networks for flocks of sheep to account for seasonal changes of the flock structure as lambs are born and eventually become weaned. We construct a range of network and ODE models that are designed to investigate the effect of link-weight heterogeneity on the spread of disease.

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47

Zinn, Brendan Anderson 1977. "Mass transfer and dispersion processes in connected conductivity structures : simulation, visualization, delineation and application". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29584.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.
Includes bibliographical references (p. 161-167).
This thesis focuses on mass transfer behavior, i.e., tailing, in solute transport, and on hydraulic conductivity heterogeneity. Macrodispersive theory, generally used to incorporate heterogeneity into solute transport, does not account for this tailing and makes assumptions about the structural characteristics of the heterogeneity, specifically that the field is multivariate gaussian. We move away from the multigaussian assumption to focus on the concept of connected pathways of high or low conductivity. We first motivate the importance of connected extreme conductivity values through the numerical creation of two-dimensional conductivity fields with nearly identical univariate conductivity distributions and covariances, but with varying connectedness of extreme values. We simulated flow and transport through these fields, using a particle tracking approach that incorporates advection and diffusion. We demonstrate that connectedness impacts flow by influencing the effective conductivity of the field, and connected high conductivity fields with relatively high variance displayed mass transfer behavior, driven by both advective and diffusive processes. We then conducted laboratory experiments to study three flow situations demonstrated by the first part of the work - classic dispersion, diffusion-driven mass transfer, and advection-driven mass transfer. By simultaneously measuring outflow concentration and the spatial distribution of solute in the tank, we demonstrate different breakthrough characteristics driven by different small-scale processes. Outflow concentrations match excellently with established models in the case of diffusive mass transfer and dispersion, and relatively well with a model we developed for the advective mass transfer scenario.
(cont.) We generalized the experimental results by creating connected binary conductivity fields, delineating the conditions of connectedness and conductivity contrast that drive the various transport. Finally, we examine the implications of our earlier work, particularly the interplay between advection and diffusion in mass transfer. The presence of both processes creates late-time concentrations that are complex, but partially dependant on hydraulic gradients. We apply this to a hypothetical scenario of a pump-and-treat remediation - the existence of advective mass transfer creates situations in which solute mobilization can be sped up by pumping rate choices, and the complex interaction between mass transfer processes leads to more complex pumping rate decisions.
by Brendan Anderson Zinn.
Ph.D.

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48

Kristiansson, Johan. "Creating always-best-connected multimedia applications for the 4:th generation wireless systems". Licentiate thesis, Luleå tekniska universitet, Datavetenskap, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25932.

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This thesis describes an application-layer framework for managing network connectivity in the 4th-generation wireless systems, which will consist of overlapping heterogeneous networks. If multiple access networks are present, users will have a choice to access the Internet through the “best” available network. The main problem today is that different wireless networks are not particularly integrated and users are in most cases forced to manually interact with the system when switching between networks. The work presented in this thesis addresses this challenge and describes a framework for managing IP mobility while considering competing connection speeds and pricing models. By using an application-layer mobility scheme, called the Resilient Mobile Socket (RMS), the thesis shows how applications can manage handovers and seamlessly migrate data streams between different networks. Moreover, by using a method called Competition based Soft Handovers (CSHM), the thesis demonstrates how handovers can be automatically triggered to the network currently offering the least packet losses and end-to-end delay. Finally, the thesis proposes bandwidth broker to manage network connectivity and share bandwidth effectively between multiple media within an application. As a proof of concept several prototypes have been built into the commercial e-meeting application Marratech Pro. The thesis presents real-life results from exploratory experiments using these prototypes.

Godkänd; 2004; 20060917 (ysko)

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49

Funderburk, Joshua A. "Intervention of Performance: Applications of Parametric Studies on Connective Design in Public Interaction". University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1617109690521955.

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50

Garcia, del Molino Luis Carlos. "Non-hermitian random matrices and applications to randomly connected firing rate neuronal networks". Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC167.

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On étudie l'impacte des propriétés statistiques des matrices de connectivité sur la dynamique des réseaux de neurones. Cette étude se fait à travers de l'analyse des propriétés spectrales de matrices aléatoires
We study the impact of the statistical properties of connectivity matrices on the dynamics of neuronal networks. This study is done by analyzing the spectral properties of random matrices

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Tesis sobre el tema "Application connectée"

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