To see the other types of publications on this topic, follow the link: Hybrid A*.
Dissertations / Theses on the topic 'Hybrid A*'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Hybrid A*.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Dao, Thi Phuong Tuyen. "Hybrid polymer/liquid vesicles as new particles for drug delivery and cell mimics." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0190/document.
Full textAbstract:
Les vésicules hybrides polymère/lipides sont des structures récemment développées dans la littérature. Idéalement, celles-ci peuvent présenter la biocompatibilité et la biofonctionnalité des liposomes, ainsi que la robustesse, la faible perméabilité et la versatilité de fonctionnalisation chimique conférées par les chaînes de copolymères. Cependant, à ce jour, les facteurs régissant la séparation des phases dans ces membranes hybrides ne sont pas bien compris. Dans ce travail, nous avons étudié en détail la formation et la séparation de phases dans les membranes de vésicules géantes (GHUVs) et de taille nanométriques(100nm) (LHUVs) constituées de phospholipides en phase fluide ou gel et de copolymères à base de poly (diméthylsiloxane) et de poly (éthylène glycol). Différentes architectures(greffée, tribloc) et masses molaires ont été utilisées. La séparation de phase a été étudiée sur les vésicules géantes à l’échelle micrométrique et nanométrique respectivement par microscopie confocale et imagerie de fluorescence résolue en temps (FLIM), tandis que pour les LHUVs, différentes techniques comme la diffusion de neutrons, la Cryo-microscopie et la spectroscopie de fluorescence résolue dans le temps ont été combinées. Nous avons pu montrer que la fraction lipide/polymère, l'état physique du lipide et la tension de la ligne aux interfaces lipide/polymère modulable par la masse molaire et l'architecture du copolymère sont les facteurs importants régissant la formation et la structuration des vésicules hybrides. Enfin, nous avons montré que les propriétés élastiques de la membrane peuvent être modulées via la composition polymère lipideHybrid copolymer/lipid vesicle are recently developed self-assembled structures that could present biocompatibility and biofunctionality of liposomes, as well as robustness, low permeability and functionality variability conferred by the copolymer chains. However, to date, physical and molecular parameters governing copolymer/lipid phase separation in these hybrid membranes are not well understood. In this work, we studied in detail the formation and phase separation in the membranes of both Giant Unilamellar Hybrid Vesicles(GHUVs) and Large Unilamellar Hybrid Vesicles (LHUVs) obtained from the mixture of phospholipids in the fluid (liquid disordered) or gel state (solid ordered) with various copolymers based on poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEO) with different architectures (grafted, triblock) and molar masses. For GHUVs, phase separation at the micron scale and nanoscale was evaluated through confocal microscopy, and Fluorescence lifetime imaging microscopy technique (FLIM) respectively, where as acombination of Small angle neutron scattering (SANS), Cryo-transmission electron microscopy (Cryo-TEM) and Time-resolved Förster resonance energy transfer (TR-FRET) techniques was used for LHUVs. We demonstrate that the lipid/polymer fraction, lipid physical state, and the line tension at lipid polymer/lipid boundaries which can be finely modulated by the molar mass and architecture of the copolymer are important factors that govern the formation and structuration of hybrid vesicles. We also evidence that elasticity ofthe hybrid membrane can be modulated via the lipid polymer composition, through the use of micropipettes techniques
2
Bladé, Tatiana. "Synthèse, caractérisation et évaluation en caoutchouc de nouvelles charges hybrides renforçantes." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14608/document.
Full textAbstract:
Pour conférer au caoutchouc naturel de meilleures propriétés mécaniques, quand il s’agit d’applications industrielles spécifiques telles que le pneumatique, il est mélangé entre autres à des charges renforçantes. L’objectif de cette thèse est double : nous nous sommes premièrement intéressés à l’élaboration d’un nouveau type de charges hybrides, composées d’une partie minérale (silice) et organique (polymère). La stratégie que nous avons développée consiste à synthétiser des nanoparticules hybrides de morphologie contrôlée par polymérisation en émulsion ensemencée et à les agréger a posteriori. Nous avons également réalisé l’étude des propriétés mécaniques d’élastomères chargés avec les charges hybrides obtenuesIt’s necessary to use filler to give better mechanical properties to the natural rubber when it is used in the making of tires. The objective of this thesis is twofold: firstly we have developed a new type of fillers composed of mineral part (silica) and organic part (polymer). The strategy that we developed is to synthesize hybrid nanoparticles of controlled morphology by seeded emulsion polymerization and to aggregate them subsequently. The second objective was to study the mechanical properties of elastomers filled with the obtained hybrid entities
3
Krilavičius, Tomas. "Hybrid techniques for hybrid systems." Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57124.
Full text
4
Höglund, Mattias. "The construction and use of interspecific somatic cell hybrids in reverse genetics an approach to the analysis of the mouse genome with special reference to the mouse chromosome 17 /." Lund : Dept. of Molecular Genetics, Institute of Genetics, University of Lund, 1992. http://books.google.com/books?id=JM1qAAAAMAAJ.
Full text
5
Romero, Alessandro Gerlinger. "Hybrid fuml: a hybrid synchronous language." Instituto Nacional de Pesquisas Espaciais (INPE), 2014. http://urlib.net/sid.inpe.br/plutao/2014/11.13.11.40.
Full textAbstract:
A noção de um sistema híbrido é centrada em torno de uma composição de comportamentos discretos e contínuos, Enquanto a dificuldade na modelagem de sistemas híbridos vem da diversidade destes sistemas, a mais promissora abordagem para mitigar este problema é desenvolver linguagens de modelagem expressivas e precisas. No entanto, desenvolver linguagens de modelagem expressivas e precisas não significa a necessidade de novas linguagens, pelo contrário, esta tese propõe semânticas precisas para subconjuntos de linguagens existentes. Subconjuntos são definidos porque expressividade e precisão geralmente conflitam. por exemplo, o tamanho e a complexidade de uma linguagem (relacionados à expressividade) podem ter consequências diretas no tamanho e complexidade de sua semântica (relacionados à precisão). Precisão significa uma semântica definida de acordo com um método formal estabelecido, além disso, reconhecendo a natureza de tempo real dos sistemas híbridos, a linguagem de modelagem deve permitir determinismo, previsibilidade e composição simples. Nesta tese, duas linguagens complementares são formalmente definidas por máquinas de estado abstrato (A8Ms). A primeira delas é chamada synchronous fUML e ela combina recursos síncronos para controle na fUML (foundational subset for- executable UML models) padronizada. A segunda delas, Hybrid fUML, é uma extensão conservativa da synchronous fUML, na qual equações algébrico-diferenciais (DAEs) são descritas usando-se um subconjunto da sintaxe concreta da Modelica, O subconjunto da Modelica é selecionado de tal forma que sua semântica é definida pela semântica matemática padrão. Hybrid fUML é uma linguagem de modelagem definida para permitir descrição e análise de visões sistêmicas de sistemas híbridos. A principal contribuição inovadora é o novo modelo de computação para extensões híbridas de linguagens síncronas, que é formalmente definido para Hybrid fUML. O novo modelo de computação é baseado no conceito enichrony, uma propriedade de modelos que permite a sincronização do tempo físico no ambiente e nos modelos. O novo modelo da computação permite determinismo, previsibilidade e composição simples de sistemas híbridos.The notion of a hybrid system is centered around a composition of discrete and continuous behaviors. Although the difficulty in modeling hybrid systems comes from the diversity of these systems, the most promising approach to mitigate this issue is developing expressive and precise modeling languages. Nevertheless, developing expressive and precise modeling languages does not necessarily mean the emergence of a new language, on the contrary, this thesis proposes precise semantics for subsets of existent languages. Subsets of existent languages are defined since expressivity and precision usually conflict, e.g., the size and complexity of a language (related to expressivity) may have direct consequences on the size and complexity of its semantics (related to precision). Precision means a semantics defined according to a well stablished formal method, furthermore, recognizing the real-time nature of hybrid systems, the modeling language have to enable determinism, predictability and straightforward composition. In this thesis, two complementary languages are formally defined by abstract state machines (ASMs). The first one is called synchronous fUML and it blends synchronous features for control into the standardized fUML (foundational subset for executable UML models). The second one, hybrid fUML, is a conservative extension of synchronous fUML in which differential algebraic equations (DAEs) are described using a subset of Modelica concrete syntax. The subset of Modelica concrete syntax is selected in such a way that its semantics is defined by the standart mathematical semantics. Hybrid fUML is a modeling language defined to enable description and analysis of system views from hybrid systems. The main innovative contribution lies in the novel model of computation for hybrid extensions of synchronous languages, which is formally defined for hybrid fUML. The novel of computation enables determinism, predictability and straightforward composition of hybrid systems.
6
Rajpurohit, Ashok. "Development of advanced carbon/glass fibre based hybrid composites." Thesis, Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLM020.
Full textAbstract:
Les composites hybrides offrent un moyen efficace d'améliorer les propriétés mécaniques des matériaux composites. Cette thèse vise à comprendre le comportement mécanique et l'effet synergique offerts par de tels composites hybrides sous plusieurs conditions de chargement. L'accent est mis, non seulement sur la caractérisation mécanique, mais également sur le développement et l'optimisation de nouvelles générations de renforts hybrides, permettant ainsi une hybridation aussi bien au niveau des nappes, qu’au niveau des mèches et des fibres. Dans ce travail, les fibres de carbone et de verre sont choisies comme les deux types de renforts pour les composites hybrides. Les propriétés de ces fibres unitaires sont d'abord caractérisées pour étudier l'impact des procédés textiles. De nouveaux renforts unidirectionnels ont été fabriqués après avoir optimisé les procédés, tels que la technologie UD cousu et l'étalement des fibres. Les composites ont été fabriqués via RTM basse pression en utilisant une résine époxy. Les caractéristiques en raideur et en résistance des composites de référence, des hybrides inter-plis, intra-plis et fibre à fibre ont ensuite été caractérisées dans des conditions de charge quasi-statique en traction, compression et flexion. L'effet d’hybridation (synergique) a été évalué pour ces composites en comparant les propriétés du composite hybride avec un composite de référence en carbone. Afin de comprendre le comportement à rupture de ces composites dans différentes conditions de charge, une étude de fractographie a été réalisée. Les hybrides inter-plis font apparaître une légère augmentation de la déformation à rupture en traction mais présentent une synergie négative pour toutes les autres conditions. Les hybrides intra-plis montrent eux, un effet synergique pour les résistances à la traction et à la compression, sans réduire leur déformation à rupture. Un composite hybride fibre à fibre réalisé par étalement montre une performance mécanique supérieure par rapport à d'autres hybrides. Les résultats présentés révèlent les avantages potentiels de l'hybridation à différents niveaux et dispersions. Les résultats ouvrent une voie pour les futurs travaux sur les composites hybrides et leurs procédésHybrid composites offer an effective way of enhancing mechanical properties of composite materials. This thesis aims to understand the mechanical behaviour and synergistic effect offered by such hybrid composites in several loading conditions. The focus not only lies on mechanical characterisation but also on development and optimization of new generation of hybrid reinforcements thus allowing hybridization both at ply levels and at tow and fibre levels. In this work, carbon and glass fibres are chosen as the two types of reinforcements for hybrid composites. Single fibre properties of these fibres were first characterised to study the effect of textile processes. Novel unidirectional reinforcements have been fabricated after optimising the processes such as unidirectional stitching and spreading technology. Composites were manufactured via low pressure RTM process using an epoxy resin. Stiffness and failure characteristics of reference, interply, intraply and intermingled hybrid composites were then characterised in quasi-static tensile, compression and flexural loading conditions. The hybrid (synergistic) effect were evaluated for these composites by comparing the hybrid composite properties with a carbon reference composite. To understand the failure behaviour under different loading conditions, a fractography study was conducted. Interply hybrids slightly increase the failure strain in tension but demonstrate negative synergy in all other properties. On the other hand, intraply hybrids show a synergistic effect in both tensile and compressive strengths, while not reducing the failure strain. A spread tape intermingled hybrid composite demonstrates a superior mechanical performance when compared to other hybrids. The presented results reveal the potential benefits of hybridisation at different levels and dispersions. The results provide a driving force for future work on hybrid composites and their processing
7
Hadjeras, Sabrina. "Hybrid control of power converters." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30087.
Full textAbstract:
Cette thèse propose la conception de lois de commandes hybrides pour les convertisseurs électroniques de puissance. Ce nouveau type de lois de commande est basé sur l'utilisation de modèles hybrides qui capturent les comportements dynamiques macroscopiques de ces dispositifs électroniques, essentiellement leur nature hybride. Dans le contexte de la régulation des convertisseurs DC-DC ou AC-DC, en appliquant la théorie des systèmes hybrides, il est ainsi prouvé que les lois de commandes proposées assurent la stabilité de la boucle fermée ainsi que certaines performances de type LQ. Pour un onduleur en demi-pont (convertisseur DC-AC), une loi de commande hybride est proposée afin que la tension de sortie suive une référence sinusoïdale souhaitée. Dans le cas d'une charge inconnue, une loi de commande adaptative est alors couplée à la commande hybride permettant l'estimation de la charge et donc une régulation ou un suivi de trajectoire plus précis. Notons que pour obtenir une régulation ou un suivi parfait, une fréquence infinie est souvent obligatoire pour les lois de contrôle proposées, ce qui est inappropriée en pratique. Pour résoudre ce problème, une régularisation de l'espace d'état ou du temps est ajoutée à la boucle fermée assurant un temps de maintien entre deux sauts consécutifs et réduisant ainsi considérablement la fréquence de commutationThis thesis proposes the design of hybrid control laws for power electronics converters. These new type of control laws are based on some hybrid models which capture the macroscopic dynamical behaviors of such electronic devices, essentially its hybrid nature. In the context of the regulation of DC-DC or AC-DC converters, applying the hybrid dynamical theory, the proposed control laws are proved to ensure the stability of the closed loop as well as some LQ performances. For a half-bridge inverter (DC-AC converter), a hybrid control law is proposed in order that the output voltage tracks a desired sinusoidal reference. In the case of unknown load, an adaptive control law is coupled to the hybrid control allowing the estimation of the load and therefore leading to a more precise regulation or tracking. Notice that in order to achieve a perfect regulation or tracking, an infinite frequency is often mandatory for the proposed control laws, which is inappropriate in practice. To tackle this problem, a space- or time-regularization are added to the hybrid closed-loop ensuring a dwell time between two consecutive jumps and reducing thus drastically the switching frequency
8
Powell, Matthew G. "Morphometric Characterization of a Mercenaria spp. (Bivalvia) Hybrid Zone: Paleontological and Evolutionary Implications." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/33094.
Full textAbstract:
Paleontological documentation of hybridization events has the potential to address a multitude of evolutionary and paleobiological issues unanswerable by purely biological means. However, previous studies of modern hybrids suggest that their morphology is often insufficient for their reliable discrimination. This study analyzes the morphology of an extant, genetically-identified Mercenaria spp. (Bivalvia: Veneridae) hybrid zone using Bookstein coordinates and multivariate methods to answer two questions: (1) can hybrid Mercenaria spp. individuals be identified based on morphology alone, and (2) would a Mercenaria spp. hybrid zone be recognizable in the fossil record?
Multivariate statistical procedures (principal components analysis, canonical variate analysis, etc.) using Bookstein coordinates demonstrate that, within the hybrid zone, hybrid individuals cannot be identified due to extreme overlap with the parental taxa. The hybrid zone as a whole, however, can be identified by comparison with pure-species populations sampled from outside the hybrid zone. Hybrid zones occupy parental species morphospace plus intermediate morphospace. The technique of using multiple pure-species populations to establish species morphospace is introduced to control for processes that may also result in morphological intermediates at ecological time scales (dimorphism, ecophenotypy, and geographic variation). Four alternative causal explanations of morphological intermediates through geological time (primary intergradation, uncoupled genetic and morphological divergence, time-averaged evolving populations, and developmentally instable populations) are evaluated. A literature survey strongly suggests that neither time-averaging nor developmental instability is occurring at the beginning of a lineageâ s evolutionary history, and that hybridization may be much more extensive than paleontological data suggest.
Master of Science
9
Shi, Qiong, and sarahshi0403@gmail com. "Hybrid City." RMIT University. Architecture and Design, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080124.122149.
Full textAbstract:
Based on the upcoming 2010 World Expo of Shanghai. According to 'moving out' policy of Shanghai government, a large percentage of residents from Shanghai's old downtown area are being moved out to a district on the outskirts of the municipality. In the context of moving out policy and shifting community space of 'Longtang' residents, my research explores how water can be used to forge a new typology for the Xinji residential area in developing Shanghai. The new typology of residential area is defined by a new type of community space. Water, edge and corridor are examined as three main concepts to create this kind of new community space, where residents can be provided with diverse spatial experience and various spatial effects through spatial transformations in and between private and public and diverse programs in a residential area. 'Longtang' is one of the key precedents I am looking at for the purpose of studying water edge conditions and corridor conditions, and to deduce a way to best design hybrid community in the Xinji residential area, which is selected as my research site. It is identified as one of the peripheral node for the moving out policy by Shanghai government? My research, therefore, tries to explore a new typology of Xinji residential area, which can provide both existing residents and 'Longtang' residents with diverse water based community space in the residential area and its context.
10
Schlierf, Andrea. "Graphene organic hybrid materials." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF050/document.
Full textAbstract:
En 2004, le carbone, la base de toute vie connue sur Terre, a marqué les esprits une fois de plus: Les scientifiques de l’Université de Manchester au Royaume Uni ont pu extraire une matière carbonée complètement nouvelle, le graphène à partir d’un morceau de graphite comme celui qui compose les crayons. À l’aide d’un ruban adhésif, ils ont obtenu une paillette de carbone de l’épaisseur d’un atome seulement, à une époque où beaucoup pensaient qu’un matériaux cristallin aussi fin ne pouvait pas être stable. Le graphène parfait est une couche monoatomique composée d’atomes de carbone hybridés sp2, arrangés en structure alvéolaire; sa structure chimique particulière lui donne des propriétés physiques et chimique remarquable. Le graphène est devenu rapidement la matière carbonée la plus intensivement étudiée parmi celles «possiblement révolutionnaires», avec ses applications potentielles s’étendant de la microélectronique aux composites, des énergies renouvelables à la médecine. En 2010, Geim et Novoselov ont été récompensés par le prix Nobel de physique pour leurs «expériences révolutionnaires sur les matériaux bi-dimensionnels en graphène» qui a ouvert une nouvelle ère dans la science des matières carbonées.La chimie non-covalente du graphène est exploitée et étudiée dans cette thèse dans le but de concevoir, produire, transformer et caractériser les nouveaux matériaux hybrides graphène-organique. L’étendue de ce travail couvre les aspects mécanistiques de l’exfoliation en phase liquide du graphène avec des colorants, les aspects fondamentaux des interactions entre le graphène et le chromophore, en phase liquide et solide, ainsi que l’élaboration de suspensions hybrides de graphène dans le but d‘applications en électronique organique et dans les matériaux composites polymères fonctionnelsIn 2004, carbon, the basis of all known life on earth, has surprised once again: Researchers from University of Manchester, UK, extracted a completely new carbon material, graphene, from a piece of graphite such as is found in pencils. Using adhesive tape, they obtained a flake of carbon with a thickness of just one single atom, at a time when many believed it impossible for such thin crystalline materials to be stable. Pristine graphene is a mono-atomic sheet of, sp2 hybridized carbon atoms arranged in a honeycomb network; this particular chemical structure gives rise to its outstanding physical and chemical properties. Graphene rapidly became the most intensively studied among the ‘possibly revolutionary’carbon materials, with its potential applications reaching from microelectronics to composites, from renewable energy to medicine. In 2010, Geim and Novoselov were honored with the Nobel Prize in Physics for their “ground breaking experiments regarding the two-dimensional material graphene” that started a new era in the science of carbon materials.In this thesis we exploit and study the non-covalent chemistry of graphene to design, produce, process and characterize novel graphene organic hybrid materials. The scope of this work covers mechanistic aspects of graphene liquid phase exfoliation with dyes, fundamental aspects of graphene chromophore interactions in liquid and solid phase and the formulation of graphene hybrid suspensions towards application in organic electronics and functional polymer composite materials
11
Yu, Lei. "Reconstruction du signal ou de l'état basé sur un espace de mesure de dimension réduite." Thesis, Cergy-Pontoise, 2011. http://www.theses.fr/2011CERG0546/document.
Full textAbstract:
Le 21_eme siècle est le siècle de l'explosion informatique, des milliards de Données sont produites, collectées et stockées dans notre vie quotidienne. Les façons de collecter les ensembles de données sont multiples mais toujours en essayant d'optimiser le critère qui consiste _a avoir le maximum d'information dans le minimum de données numérique. Il est préférable de collecter directement l'information, car les informations étant contraintes sont dans un espace plus faible que celui où évolues les données (signaux ou états). Cette méthode est donc appelée \la collecte de l'information", et conceptuellement peut ^être résumée dans les trois étapes suivantes : (1) la modélisation, ceci consiste _a condenser l'information pertinente pour les signaux _a un sous-espace plus petit; (2) l'acquisition, ceci consiste _a collecter et préserver l'information dans un espace inferieur _a la dimension des données et (3) la restauration, ceci consiste _a reconstituer l'information dans son espace d'origine. En suivant cette pensée, les principales contributions de cette thèse, concernant les observateurs et le \Compressive Sensing" (CS) basé sur des modèles bay_esiens peuvent ^être unies dans le cadre de la collecte de l'information : les principaux problèmes concernés par ces deux applications peuvent ^être de façon analogue, scindés en les trois étapes sus- mentionnées. Dans la première partie de la th_ese, le problème réside dans le domaine des systèmes dynamiques où l'objectif est de retrouver l'état du système _a partir de la mesure de la sortie. Il nous faut donc déterminer si les états du système sont récupérables _a partir des mesures de la sortie et de la connaissance partielle ou totale du modèle dynamique, c'est le problème de l'observabilité. Ensuite de transposer notre problème dans une représentation plus appropriée, c'est l'écriture sous forme normale et en récupérer l'information, c'est la phase de synthèse d'observateur. Plus précisément dans cette partie, nous avons considéré une classe de systèmes à commutation haute fréquence allant jusqu'au phénomène de Zénon. Pour ces deux types de commutation les transitions de l'état discret sont considérées trop élevées pour ^être mesurées. Toutefois, la valeur moyenne obtenue par filtrage des transitions peut ^être acquise ce qui donne une connaissance partielle des états discrets. Ici, avec ces seuls informations partielles, nous avons discuté de l'observabilité et ceci par les approches géométrie différentielle et algébrique. Aussi, des observateurs ont été proposes par la suite. Dans la deuxième partie de cette thèse, nous avons abordé de la même manière le thème du CS qui est une alternative efficace à l'acquisition abondante de données faiblement informatives pour ensuite les compresser. Le CS se propose de collecter l'information directement de façon compressée, ici les points clés sont la modélisation du signal en fonction des connaissances a priori dont on dispose, ainsi que la construction d'une matrice de mesure satisfaisant la \restricted isometry property" et finalement la restauration des signaux originaux clairsemés en utilisant des algorithmes d'éparpillement régularisé et d'inversion linéaire. Plus précisément, dans cette seconde partie, en considérant les propriétés du CS liées _a la modélisation, la capture et la restauration, il est proposé : (1) d'exploiter les séquences chaotiques pour construire la matrice de mesure qui est appelée la matrice chaotique de mesure, (2) considérer des types de modèle de signal clairsemé et reconstruire le modèle du signal à partir de ces structures sous-jacentes des modèles clairsemés, et (3) proposer trois algorithmes non paramétriques pour la méthode bayesienne hiérarchique. Dans cette dernière partie, des résultats expérimentaux prouvent d'une part que la matrice chaotique de mesure a des propriétés semblables aux matrices aléatoires sous-gaussienne et d'autre part que des informations supplémentaires sur les structures sous-jacentes clairsemés améliorent grandement les performances de reconstruction du signal et sa robustesse vis-a-vis du bruitThis is the era of information-explosion, billions of data are produced, collected and then stored in our daily life. The manners of collecting the data sets are various but always following the criteria { the less data while the more information. Thus the most favorite way is to directly measure the information, which, commonly, resides in a lower dimensional space than its carrier, namely, the data (signals or states). This method is thus called information measuring, and conceptually can be concluded in a framework with the following three steps: (1) modeling, to condense the information relevant to signals to a small subspace; (2) measuring, to preserve the information in lower dimensional measurement space; and (3) restoring, to reconstruct signals from the lower dimensional measurements. From this vein, the main contributions of this thesis, saying observer and model based Bayesian compressive sensing can be well uni_ed in the framework of information measuring: the main concerned problems of both applications can be decomposed into the above three aspects. In the _rst part, the problem is resided in the domain of control systems where the objective of observer design is located in the observability to determine whether the system states are recoverable and observation of the system states from the lower dimensional measurements (commonly but not restrictively). Speci_cally, we considered a class of switched systems with high switching frequency, or even with Zeno phenomenon, where the transitions of the discrete state are too high to be captured. However, the averaged value obtained through filtering the transitions can be easily sensed as the partial knowledge. Consequently, only with this partial knowledge, we discussed the observability respectively from differential geometric approach and algebraic approach and the corresponding observers are designed as well. At the second part, we switched to the topic of compressive sensing which is objected to sampling the sparse signals directly in a compressed manner, where the central fundamentals are resided in signal modeling according to available priors, constructing sensing matrix satisfying the so-called restricted isometry property and restoring the original sparse signals using sparse regularized linear inversion algorithms. Respectively, considering the properties of CS related to modeling, measuring and restoring, we propose to (1) exploit the chaotic sequences to construct the sensing matrix (or measuring operator) which is called chaotic sensing matrix, (2) further consider the sparsity model and then rebuild the signal model to consider structures underlying the sparsity patterns, and (3) propose three non-parametric algorithms through the hierarchical Bayesian method. And the experimental results prove that the chaotic sensing matrix is with the similar property to sub-Gaussian random matrix and the additional consideration on structures underlying sparsity patterns largely improves the performances of reconstruction and robustness
12
Batis, Sonia. "Commande d'une classe de systèmes hybrides par automates hybrides rectangulaires." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT025/document.
Full textAbstract:
Notre travail de recherche concerne l’étude de la commande à base de modèles pour une sous-classe de systèmes dynamiques hybrides (SDH). L’outil de modélisation choisi est l’automate hybride rectangulaire (AHR) pour sa puissance d’analyse. Nous proposons ainsi une méthode pour la synthèse de la commande des SDH modélisés par des AHR. Cette méthode repose sur l’application d’une procédure amont/aval de commande hors-ligne qui détermine d’une façon maximale permissive les nouvelles gardes de transition de l’automate respectant des spécifications de commande imposées par l’utilisateur. Tous les calculs réalisés reposent sur la détermination de la durée de séjour, valeur contrainte par l’espace atteignable du sommet correspondant. La garde portant à la fois sur l’état continu et sur l’événement discret, la commande se fait par ce dernier car il s’agit du seul élément contrôlable. Nous nous intéressons alors à la construction du contrôleur temporisé autorisant l’occurrence des événements contrôlables du système dans un intervalle d’horloge défini au sens de la maximale permissivitéIn this thesis, we study the control of a class of hybrid dynamic systems (HDS). The chosen modeling tool is the rectangular hybrid automaton (RHA) for his analysis power. We propose a method for the control synthesis of HDS modeled with RHA. This method consists on the application of a downstream/upstream offline control procedure that determines in a maximal permissive way the new automaton transition guards respecting the desired control specifications. All computations are based on the determination of the duration of stay, a value constrained by the reachable space of the corresponding location. Since the guard refers to both continuous state and discrete event, the control is made by the latter because it is the controllable element. Then we are interested in the construction of the timed controller authorizing the system controllable event occurrence in a clock interval defined in a maximal permissive way
13
Fibbe, Gijs. "EC law aspects of hybrid entities = EG rechtelijke aspecten van hybride entiteiten /." Rotterdam, 2009. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000260455.
Full text
14
Aijazi, Ahmed Tausif. "Hybrid Color Halftoning." Thesis, Linköping University, Department of Science and Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56737.
Full textAbstract:
Halftoning methods can be divided into two main categories, namely AM (Amplitude Modulated) and FM (Frequency Modulated). Some printing methods, such as Flexography, are not able to produce dots small enough to handle the highlights and the shadows of the original image by just using AM halftoning method. To overcome this problem FM method is used in the highlights (and the shadows) and an AM method in rest of the image.
Hybrid halftoning (combination of AM and FM) technique for grayscale images has already be presented showing the best way to place FM and AM dots in the resulting binary image. This thesis work is and extension of that and presents hybrid technique for color images. In color images, besides the problem of transition area between AM and FM, a number of other factors needs to be addressed. One of such factors is to define the starting point of FM technique in different color channels. In this work all the possibilities of combining AM and FM in different color channels have been investigated and then the best approach for hybrid color halftoning is proposed. This approach not only uses the best solution for starting point of FM halftoning in each channel but also places the different color dots in the highlights, as homogenously as possible.
15
BerovicÌ, Daniel Philip. "Optimal hybrid control." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408766.
Full text
16
Calton, Paul. "Hybrid command module." Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415756.
Full text
17
Wang, Ji-yong 1967. "Hybrid ultrasonic array." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/84216.
Full text
18
Kao, Hsin-Liu (Hsin-Liu Cindy). "Hybrid body craft." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120684.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 209-223).
Sensor device miniaturization and breakthroughs in novel materials are allowing for the placement of technology increasingly close to our physical bodies. However, unlike all other media, the human body is not simply another surface for enhancement - it is the substance of life, one that encompasses the complexity of individual and social identity. The human body is inseparable from the cultural, the social, and the political, yet technologies for placement on the body have often been developed separately from these considerations, with an emphasis on engineering breakthroughs. This dissertation investigates opportunities for cultural interventions in the development of technologies that move beyond wearable clothing and accessories, and that are purposefully designed to be placed directly on the skin surface. How can we design emerging on-body interfaces to reflect existing cultural practices of decorating the body, with the intent to expand the agency of self-expression? This dissertation looks at this question through the development of a series of research artifacts, and the contextualization of a design space for culturally sensitive design. In this dissertation, Body Craft is defined as existing cultural, historical, and fashion-driven practices and rituals associated with body decoration, ornamentation, and modification. As its name implies, Hybrid Body Craft (HBC) is an attempt to hybridize technology with body craft materials, form factors, and application rituals, with the intention of integrating existing cultural practices with new technological functions that have no prior relationships with the human body. With this grounding, HBC seeks to support the generation of future technologized customs in which technology is integrated into culturally meaningful body adornments. The artifacts in this dissertation encompass the integration of technologies such as flexible electronics, chemical processes, and bio-compatible materials into existing Body Craft customs. These artifacts contribute novel, culturally inspired form factors, and introduce unprecedented interaction modalities for on-body technologies. A design space is created in which to examine shifts in the communicative qualities of these Body Crafts due to the integration of technology, as well as new forms of self-expression that have emerged. This dissertation contributes a culturally sensitive lens to the design of on-body technologies. The intention is to expand their lifetimes and purposes beyond mere novelty and into the realms of cultural customs and traditions.
by Hsin-Liu (Cindy) Kao.
Ph. D.
19
Ahlberg, Johan, and Anton Jansson. "Corporate Hybrid Bonds." Thesis, KTH, Fastigheter och byggande, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190205.
Full textAbstract:
Hybrid securities do not constitute a new phenomenon in the Swedish capital markets. Most commonly, hybrids issued by Swedish real estate companies in recent years are preference shares. Corporate hybrid bonds on the other hand may be considered as somewhat of a new-born child in the family of hybrid instruments. These do, as all other hybrid securities, share some equity-like and some debt-like characteristics. Nevertheless, since 2013 the interest for the instrument has grown rapidly and has become a well-accepted, as well as a fairly standardized, source of financing for many well-established corporations around the world. Yet, we have seen very few issues in Sweden and no issues by Swedish real estate companies. Corporate hybrid bonds could in a rather simplified manner be explained as a subordinated bond with some equity characteristics. Examples of such equity characteristics are perpetual maturity (or at least very long), coupon deferability and the fact that it due to its subordination provides significant loss absorption. Yet, it also holds typical debt-like characteristics such as regular coupon payments and seniority to equity. The outcome of this research has shown that issuing corporate hybrid bonds could be beneficial to a firm. Coupon payments are, unlike dividend payments to holders of preference shares but alike interest payments on a standard bank loan, tax deductible. Other probable advantages with corporate hybrid bonds are; a stronger credit profile (which potentially could improve the (shadow)credit-rating and thus also the terms of other sources of finance), a diversified investment base as well as diversification from a capital structure perspective. However, despite the many advantages, numerous obstacles remain. The main shortcoming highlighted among potential issuers is the high pricing of the instrument in relation to other alternatives. Moreover, the lack of Swedish investors investing in hybrid bonds, the assumingly poor liquidity of the product along with the high denomination (piece price) due to regulatory legislations make up for topics of concern among both potential investors and issuers. Although, considering the many benefits, we believe that the weaknesses can be overseen and that there is a potential future use for the product in event of further expansion and acquisition or if the access to capital markets is limited. After all, all good things take time.Hybrid-instrument är i sig inget nytt fenomen på den svenska kapitalmarknaden. Mest förekommande bland svenska fastighetsbolag under de senaste åren är preferensaktier. Hybrid-obligationer å andra sidan kan betraktas som något av ett nyfött barn i familjen av hybridinstrument. Dessa delar, likt alla andra hybrid-papper, några eget-kapital-liknande och vissa skuld-liknande egenskaper. Sedan 2013 har intresset för instrumentet dock vuxit snabbt och blivit en väl accepterad, liksom en relativt standardiserad, finansieringskälla för många väletablerade företag runt om i världen. Ändå har vi sett mycket få emissioner i Sverige och inga av svenska fastighetsbolag. Hybridobligationer skulle på ett förenklat sätt förklaras som en underordnad obligation med vissa eget-kapital-egenskaper. Exempel på sådana egenskaper är evig löptid (eller åtminstone mycket lång), möjlighet att ställa in kupong-utbetalningar utan att vara i default och det faktum att det på grund av dess underordnad erbjuder betydande säkerhet för senior kreditgivare. Samtidigt innehar instrumentet också typiska skuldliknande egenskaper såsom regelbundna kupongbetalningar och senioritet till eget kapital. Resultatet av denna uppsats har visat en emission av hybridobligationer kan vara till nytta för ett företag. Kupongbetalningarna är, till skillnad från utdelning till innehavare av preferensaktier men likt räntebetalningar på ett vanligt banklån, skattemässigt avdragsgilla. Andra troliga fördelar med hybridobligationer är en starkare kreditprofil (som skulle kunna förbättra ett företags kreditbetyg och därmed också villkoren för andra finansieringskällor), en diversifierad investerarbas samt diversifiering ur ett kapitalstruktur-perspektiv. Trots de många fördelar består många hinder. Huvudsakligen lyfts den höga prissättningen av instrumentet i förhållande till andra alternativ fram bland potentiella emittenter som ett hinder. Dessutom utgör bristen på svenska investerare som investerar i hybridobligationer, den tänkbart dåliga likviditen samt den höga denomineringen (styckepris) skäl till oro bland både potentiella investerare och emittenter. Med bakgrund i de många fördelarna, anser vi att de brister som kvarstår går att kringgå och att det finns en potentiell framtida användning för produkten i händelse av ytterligare expansion och förvärv eller om tillgången till kapitalmarknaderna är begränsad. Trots allt, alla goda saker tar tid.
20
Placide, Eustache. "Hybrid pattern recognition." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1987. http://digitalcommons.auctr.edu/dissertations/3018.
Full textAbstract:
There are two basic approaches to pattern recognition: decision-theoretic and syntactic. However, in actual applications, a combination of both may be needed. One such hybrid technique consists of syntactic method coupled with stochasticity in its grammar. Randomness in the syntactic case is caused due to noise and insufficient information about characteristics of pattern classes. To absorb the effect of this randomness, the grammar must be generalized to include the probabilities of production rules.
In this paper, a preliminary discussion of issues involved with hybrid techniques, in general, and stochastic grammars, in particular, is provided. An efficient algorithm for an automatic learning of production probabilities is devised. Concepts are illustrated via examples.
21
Atlayan, Ozgur. "Hybrid Steel Frames." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/50562.
Full textAbstract:
The buildings that are designed according to the building codes generally perform well at severe performance objectives (like life safety) under high earthquake hazard levels. However, the building performance at low performance objectives (like immediate occupancy) under low earthquake hazards is uncertain. The motivation of this research is to modify the design and detailing rules to make the traditional systems perform better at multi-level hazards.This research introduces two new structural steel systems: hybrid Buckling Restrained Braced Frames (BRBF) and hybrid steel Moment Frames (MF). The "hybrid" term for the BRBF system comes from the use of different steel material including carbon steel (A36), high-performance steel (HPS) and low yield point (LYP) steel. The hybridity of the moment frames is related to the sequence in the plastification of the system which is provided by using weaker and stronger girder sections. Alternative moment frame connections incorporating the use of LYP steel plates are also investigated.
The hybrid BRBF approach was evaluated on seventeen regular (standard) frames with different story heights, seismic design categories and building plans. By varying the steel areas and materials in the BRB cores, three hybrid BRBFs were developed for each regular (standard) frame and their behavior was compared against each other through pushover and incremental dynamic analyses. The benefits of the hybridity were presented using different damage measures such as story accelerations, interstory drifts, and residual displacements. Collapse performance evaluation was also provided.
The performance of hybrid moment frames was investigated on a design space including forty-two moment frame archetypes. Two different hybrid combinations were implemented in the designs with different column sections and different strong column-weak beam (SC/WB) ratios. The efficiency of the hybrid moment frame in which only the girder sizes were changed to control the plastification was compared with regular moment frame designs with higher SC/WB ratios. As side studies, the effect of shallow and deep column sections and SC/WB ratios on the moment frame behavior were also investigated.
In order to provide adequate ductility in the reduced capacity bays with special detailing, alternative hybrid moment frame connections adapting the use of low strength steel were also studied.
PhD
22
Constansis, Alexandros N. "Hybrid vocal personae." Thesis, University of York, 2009. http://etheses.whiterose.ac.uk/14216/.
Full text
23
Saenger, Pierre. "Optimisation et gestion d'énergie d'un système hybride électrique embarqué." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD061/document.
Full textAbstract:
Les aéronefs « plus électriques » permettent de réduire la masse à embarquer, les émissions de gaz à effet de serre et la consommation de carburant. Leur développement nécessite d'adapter leur architecture électrique et leur capacité de production et de stockage d'énergie.Les systèmes de production et de stockage doivent être bien dimensionnés pour correspondre aux besoins énergétiques du véhicule. Une hybridation électrique entre un pack constitué de batteries lithium-ion et un pack de supercondensateurs peuvent répondre, respectivement, aux demandes en énergie et en puissance de la charge.Différentes architectures électriques permettant cette hybridation sont prises en compte. Ce travail de recherche traite du dimensionnement optimal de ces systèmes de stockage à bord d’un hélicoptère.Dans cette application particulière, la masse globale de l'ensemble du système de stockage doit être minimisé. Un outil de dimensionnement optimal est développé pour atteindre cet objectif en agissant sur la fréquence de coupure d’un filtre passe-bas. A partir du profil de mission le plus contraignant en énergie et en puissance demandées, cette approche fréquentielle permet la répartition de la demande de puissance entre nos deux systèmes de stockage et, donc, leur caractérisation.Les résultats d'optimisation obtenus par architecture électrique avec la méthode du recuit simulée, sont présentés et évalués dans toute la gamme de températures. Egalement, une adaptation de la stratégie de gestion de l'énergie est présentée pour tenir compte de l'influence de la température sur les performances de la batterieThe "more electric" aircrafts reduce the embedded weight, greenhouse gas emissions and fuel consumption. Their development requires to adapt their electrical architecture and their energy production and storage capacity.Production and storage systems must be well dimensioned to match thevehicle energy requirements. An electric hybridization integrating alithium-ion battery pack and a supercapacitor pack can respectively respond to the energy and power demands of the load.Different electrical hybridization architectures will be studied. This research project deals with the optimal designs of these storage systems on board a helicopter.In this particular application, the overall mass of the entire storagetank system must be minimized. An optimal sizing tool is developed toachieve this objective by acting on the cut-off frequency of alow-pass filter. This frequency approach, based on the most demanding mission profile in terms of energy and power, allows the allocation of power demand between our two storage systems and, therefore, their characterization.Optimization results obtained by electrical architecture using thesimulated annealing method are presented and evaluated over the entiretemperature range. An adaptation of the energy managementstrategy is also presented to evaluate the influence of temperature on battery performance
24
Vento, Jorge. "Methodologies for hybrid systems diagnosis based on the hybrid automaton framework." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/276182.
Full textAbstract:
Hybrid systems play an important role in the modeling of complex systems since they take into account the interaction between both continuous dynamics and discrete events. Complex systems are subject to changes in the dynamics due to several factors such as nonlinearities, changes in the parameters, disturbances, faults, discrete events and controller actions among others. These facts lead to the need to develop a diagnostic system for hybrid systems improving the diagnostic precision. Hybrid systems allow to combine the classic fault detection and isolation approaches and a diagnoser based on discrete event models. Hence, a design methodology and implementation architecture for diagnosers in the
framework of hybrid systems is proposed.
The design methodology is based on the hybrid automaton model that represents the system behavior by means of the interaction of continuous dynamics and discrete events. The architecture is composed of modules which carry out mode recognition and diagnostic tasks interacting each other, since the diagnosis module adapts accordingly to the current hybrid system mode. The mode recognition task involves detecting and identifying a mode change by determining the set of residuals that are consistent with the current hybrid system mode. On the other hand, the diagnostic task involves detecting and isolating two type of faults: structural and non-structural faults. In the first case, structural faults are represented by a dynamic model as in the case of nominal modes. Hence they are identified by consistency checking through the set of
residuals. In the second case, non-structural faults do not change the structure of the model, therefore, they are identified by a proper residual pattern. %the set of of residuals that can explain this inconsistency.
Discernibility is the main property used in hybrid systems diagnosis. Through the concept of discernibility it is possible to predict whether modes changes (faulty or nominal) in the hybrid model can be detected and isolated properly. This concept can be applied in practice, evaluating a set of mathematical properties derived from residual expressions, which can be obtained from input-output models or parity space equations. General properties are derived to evaluate the discernibility between modes in the hybrid automaton model.
The diagnoser is built through propagation algorithms developed for discrete models represented by automata. The automaton employed to build the diagnoser for a hybrid system is named behaviour automaton. It gathers all information provided by discernibility properties between modes and observable events in the system, increasing the system diagnosability. % in the system.
Diagnosis for hybrid systems can be divided in two stages: offline and online. Moreover, it can be carried out twofold: in a non-incremental and an incremental form. In the non-incremental form, algorithms are executed taking into account global models, unlike incremental form that leads to building the useful parts of the diagnoser, only developing the branches that are needed to explain the occurrence of incoming events. The resulting diagnoser adapts to the system operational life and it is much less demanding in terms of memory storage than building the full diagnoser offline. The methodology is validated by the application to a case study based on a representative part of the Barcelona sewer network by means of a tool
implemented in Matlab.
25
Pálsson, Daði Snær. "Hybrid Ventilation : Simulation of Natural Airflow in a Hybrid Ventilation System." Thesis, KTH, Installations- och energisystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-146761.
Full textAbstract:
This thesis investigates the possibilities of using hybrid ventilation in an office building in Stockholm. The focus is on simulating the natural airflow to find out for which conditions it is sufficient. The thesis is done at White Arkitekter AB in cooperation and under the supervision of environmental specialists working there. A literature study is carried out to study what has been done before in Sweden as well as in other countries. Computer simulations are used to simulate the airflow to examine the conditions and architecture. A synthetic computer model representing a realistic office building is built up as a starting point. The ventilation method for the natural ventilation part is to take air in through the fa\c{c}ade and use the stack effects in an atrium for natural ventilation. By altering the architecture and the sizes of the openings according to the results from the simulations the building is dimensioned and formed to cope with the rules and requirements about the indoor air quality in workplaces. The simulations are done with a multi zone energy performance simulation tool that can simulate airflows and indoor air climate conditions in the zones as well as the energy consumption. Computational fluid dynamics calculations are then used to more closely simulate the conditions within the zones. The results from those simulations suggest that the natural ventilation as a part of a hybrid ventilation works for all the floors of the building for up to 10$\,^{\circ}\mathrm{C}$. The computational fluid dynamics simulations showed that the thermal comfort of all the occupants is fulfilled for these conditions but there is a risk of occupants experiencing draught because of to high velocities in the air especially for the colder outdoor temperatures. For the higher outdoor temperatures the airflow needs to be enforced to ensure sufficient conditions for the occupants and for the colder temperatures mechanical ventilation is needed to decrease heat losses and avoid the risk of draught.
26
Üzer, Ferit. "Hybrid mapping for large urban environments." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22675/document.
Full textAbstract:
Dans cette thèse, nous présentons une nouvelle méthode de cartographie visuelle hybride qui exploite des informations métriques, topologiques et sémantiques. Notre but est de réduire le coût calculatoire par rapport à des techniques de cartographie purement métriques. Comparé à de la cartographie topologique, nous voulons plus de précision ainsi que la possibilité d’utiliser la carte pour le guidage de robots. Cette méthode hybride de construction de carte comprend deux étapes. La première étape peut être vue comme une carte topo-métrique avec des nœuds correspondants à certaines régions de l’environnement. Ces cartes sont ensuite complétées avec des données métriques aux nœuds correspondant à des sous-séquences d’images acquises quand le robot revenait dans des zones préalablement visitées. La deuxième étape augmente ce modèle en ajoutant des informations sémantiques. Une classification est effectuée sur la base des informations métriques en utilisant des champs de Markov conditionnels (CRF) pour donner un label sémantique à la trajectoire locale du robot (la route dans notre cas) qui peut être "doit", "virage" ou "intersection". L’information métrique des secteurs de route en virage ou en intersection est conservée alors que la métrique des lignes droites est effacée de la carte finale. La fermeture de boucle n’est réalisée que dans les intersections ce qui accroît l’efficacité du calcul et la précision de la carte. En intégrant tous ces nouveaux algorithmes, cette méthode hybride est robuste et peut être étendue à des environnements de grande taille. Elle peut être utilisée pour la navigation d’un robot mobile ou d’un véhicule autonome en environnement urbain. Nous présentons des résultats expérimentaux obtenus sur des jeux de données publics acquis en milieu urbain pour démontrer l’efficacité de l’approche proposéeIn this thesis, a novel vision based hybrid mapping framework which exploits metric, topological and semantic information is presented. We aim to obtain better computational efficiency than pure metrical mapping techniques, better accuracy as well as usability for robot guidance compared to the topological mapping. A crucial step of any mapping system is the loop closure detection which is the ability of knowing if the robot is revisiting a previously mapped area. Therefore, we first propose a hierarchical loop closure detection framework which also constructs the global topological structure of our hybrid map. Using this loop closure detection module, a hybrid mapping framework is proposed in two step. The first step can be understood as a topo-metric map with nodes corresponding to certain regions in the environment. Each node in turn is made up of a set of images acquired in that region. These maps are further augmented with metric information at those nodes which correspond to image sub-sequences acquired while the robot is revisiting the previously mapped area. The second step augments this model by using road semantics. A Conditional Random Field based classification on the metric reconstruction is used to semantically label the local robot path (road in our case) as straight, curved or junctions. Metric information of regions with curved roads and junctions is retained while that of other regions is discarded in the final map. Loop closure is performed only on junctions thereby increasing the efficiency and also accuracy of the map. By incorporating all of these new algorithms, the hybrid framework presented can perform as a robust, scalable SLAM approach, or act as a main part of a navigation tool which could be used on a mobile robot or an autonomous car in outdoor urban environments. Experimental results obtained on public datasets acquired in challenging urban environments are provided to demonstrate our approach
27
Udagama, Ravindra. "Synthesis of polymer-polymer hybrids by miniemulsion polymerisation and characterisation of hybrid latex." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00916670.
Full textAbstract:
The objectives of work presented in this thesis are to understand droplet and particle formulation processes in order to make useful polymer-polymer hybrids in aqueous dispersions and use our fundamental understanding of these processes to: 1. Improve monomer conversion as much as possible. 2. Understand impact of these processes on hybrid film properties. Specific case studies of interest under commercially feasible conditions (i.e. solids content of 50wt %) were done based on two systems namely alkyd-acrylic and polyurethane-acrylic. Miniemulsification, miniemulsion polymerisation and characterisation of hybrid latex, chemical incorporation of alkyd and polyurethane to acrylic monomers were studied in detail. We have been able to successfully synthesise and characterise hybrid latex of about 100nm in particle diameter and high solids content (50wt %) to be used in coating and adhesive applications
28
Bogomolov, Sergiy [Verfasser], and Andreas [Akademischer Betreuer] Podelski. "Abstraction-based analysis of hybrid automata = Abstraktions-basierte Analyse von Hybrid-Automaten." Freiburg : Universität, 2015. http://d-nb.info/1123489793/34.
Full text
29
Al-Khodairi, Fahad Abdul Aziz. "Static and dynamic properties of unidirectional hybrid resin and hybrid fibre composites." Thesis, Brunel University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296214.
Full text
30
Hinnenthal, Kristian [Verfasser]. "Models and algorithms for hybrid networks and hybrid programmable matter / Kristian Hinnenthal." Paderborn : Universitätsbibliothek, 2021. http://d-nb.info/1241183112/34.
Full text
31
Crawford, Daniel. "Outcomes for the Hybrid Approach to First State Treatment of Hypoplastic Left Heart Syndrome." Thesis, The University of Arizona, 2018. http://hdl.handle.net/10150/627198.
Full textAbstract:
A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.BACKGROUND & SIGNIFICANCE Hypoplastic left heart syndrome (HLHS) is a congenital condition that involves hypoplasia or atresia of left heart structures. Treatment requires three separate interventions, and the “hybrid” procedure is a less invasive alternative to the initial open-heart operation. This approach has become favorable for certain patients in recent years, but there is a need to better understand the outcomes and the factors that influence the outcomes for hybrid Stage 1 palliation of HLHS.
32
Laporte, Rémy. "Hybrid Electric PowertrainComparative Study." Thesis, KTH, Fordonsdynamik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118795.
Full textAbstract:
New trends for environmentally-friendly mobility are rising and expectations derived from customers are significant. Urban areas such as London or even Stockholm are starting to build urban tolls by charging conventional vehicles while full‐electric powered vehicles are exempted. Carbon taxes will be certainly introduced at the EU scale in the next decade, which will strengthen those expectations of transportation changes especially regarding private vehicles. High electrification degree of conventional vehicles has to be performed to answer to those expectations. To avoid range restriction mainly related to the energy content limitations in battery electric vehicles (BEV), fuel tank has to be kept in conjunction with internal combustion engine. Thereby, according to this statement, the design of either a plug‐in hybrid electric vehicle (PHEV) or a range extender (REX) in a second extent with an extensive full‐electric range is relevant in the next decade.
33
Zhang, Taiping. "Plasmonic-Photonic Hybrid Nanodevice." Phd thesis, Ecole Centrale de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00904658.
Full textAbstract:
Metallic nano-particles or nano-antennas (NAs) provide a strong spatial confinement down to the sub wavelength regime. However, a key challenge is to address and collect light from those nano-scale systems. The tiny active area of the NA is both an advantage for its miniaturization, and a real limit for the level of the collected signal. Therefore, one needs to reconsider how to drive efficiently such NA. Here, we propose to tackle this important issue by designing and realizing a novel nano-optical device based on the use of a photonic crystal cavity (PC cavity) to generate an efficient coupling between the external source and a NA. In this thesis, we design and realize a novel nano-optical device based on the coupling engineering of a photonic crystal (PC) cavity and a nanoantenna (NA). The research work includes nanodevice design, fabrication and characterization. The PC structures are formed in an InP-based membrane with four InAsP quantum wells are in the centre of the membrane to act as an optical gain material of laser mode. The PC structures include defect mode PC structures and Bloch mode PC structures. The bowtie NAs are placed on the backbone of the PC structures. The fabrication of the PC is done by electron beam lithography. Reactive ion beam etching (RIBE) is used to transmit the patterns of PC structures into the InP layer. The NAs are then deterministically positioned on the PC structures by a second e-beam exposure followed by a lift-off process. Overlay measurements showed that the deviation in the alignment error could be as small as 20nm.Optical properties of the hybrid structure are investigated in both far-field and near-field. The far-field measurement shows that the NA increases the lasing threshold of the PC cavity. The wavelength of the laser is also impacted. Near-field scanning optical microscopy (SNOM) has employed to investigate the near-field optical field distribution. The measurement results show that the NA modifies the mode of the structure and localizes the optical field under it. The modification depends on the position and orientation of the NA.
34
Reeves, Timothy Blayne. "Hybrid coaxial cavity dielectrometer." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0018/MQ47087.pdf.
Full text
35
So, Kam Chau. "Resistive hybrid tactile sensor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0031/MQ60187.pdf.
Full text
36
Ray, Oliver. "Hybrid abductive inductive learning." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428111.
Full text
37
Psaltas, Michael A. "Hybrid cogeneration desalination process." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576090.
Full textAbstract:
Supplies of potable water from the conventional resources are descending due to increased industrialization;' extensive irrigation and rapid population growth. In Cyprus, a country without any perennial river, fixed rainy season and depleted natural aquifers faces severe water shortage in future. Desalination along with power cogeneration certainly poses as the most suitable option in the long run to avoid any water scarcity and rationing. This dissertation introduces all the major desalination processes and is focused on the commercially employed desalination processes. The processes have been discussed in relation with their history, principle, capacity, costs, market capitalization, energy consumption, required pre treatments, future growth potential and their environmental effects. The dissertation extensively investigates Cyprus' existing water resources, water scarcity in Cyprus, the need and existing desalination including the overall power generation capacity. This dissertation is unique in the sense of covering all the major desalination processes and investigating the Cyprus water resources as a whole outlining the need for commercially viable desalination and power, cogeneration facilities. The aim of this study is to expand the existing MSF systems to a higher level for potential changes which they will help the industrial desalination in increasing the efficiency and reducing the costs. This is a new three stage distillation system which will be designed and constructed in Cyprus. The plant will be manufactured from local materials by local manpower and requires little maintenance and operating costs. Hence it offers relatively higher efficiency which enables this system to be more cost effective.
38
Hoffman-Hussain, Candace Lynn. "Exploring interfaith hybrid coupledom." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.661128.
Full textAbstract:
This thesis offers an important contribution to scholarly debates on belonging, hybridity and the role of the home through its focus on the connection between home-making practices and interfaith hybrid coupledom. I draw from five feminist case study interviews of couples comprised of British Muslim men who are first or second generation immigrants and women with Christian backgrounds. I explore the way their narratives on home-making practices, including the use of home artefacts, demonstrate fluid, intersectional and multi-scalar belonging within their examples of interfaith hybrid coupledom. The interviewees' nal1"atives have been organised into five themes which relate to coupledom practices. In Chapter Four, I examine the way the interviewees' home artefacts were significant to 'feelings settled' in the house moving process. In Chapter Five: 'Multiple Home Decorating', I argue that the negotiation of decorating styles suggests the intersection of gendered, national and cultural belonging, and that the female interviewees' support their partners' homing desires via home artefacts. In Chapter Six: 'Interfaith Home Decorating', I suggest that the interviewees' narratives around the use or absence of religious home aliefacts express intersectional belonging. In Chapter Seven: 'Gift-Giving', I argue that gift-giving expresses intersectional belonging and connections with close family and friends. In Chapter Eight: 'Cooking and Eating', I explore the shifting of gendered expectations, national belonging and the impact of cultural and religious belonging. The overall key findings include the intersection of gender and religion on home-making discussions, the effect of 'flow' on ordering home artefacts (Cwerner and MetCalfe, 2003), the importance of memories in the home-making process (Jacobson, 2009; Barbey, 1988) and the impact of class-based belonging on home-making (Reed, 2006; Jacobs, 2003; Bourdieu, 1984). Nonetheless, I have asserted that the case study interviewees have revealed how one can merely glimpse into the intersectional belonging (Yuval-Davis, 2006b) within interfaith hybrid coupledom.
39
Cai, Qiong. "Hybrid molecular dynamics simulation." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/10849.
Full text
40
Ghauri, Farzan Naseer. "Hybrid Photonic Signal Processing." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3233.
Full textAbstract:
This thesis proposes research of novel hybrid photonic signal processing systems in the areas of optical communications, test and measurement, RF signal processing and extreme environment optical sensors. It will be shown that use of innovative hybrid techniques allows design of photonic signal processing systems with superior performance parameters and enhanced capabilities. These applications can be divided into domains of analog-digital hybrid signal processing applications and free-space--fiber-coupled hybrid optical sensors. The analog-digital hybrid signal processing applications include a high-performance analog-digital hybrid MEMS variable optical attenuator that can simultaneously provide high dynamic range as well as high resolution attenuation controls; an analog-digital hybrid MEMS beam profiler that allows high-power watt-level laser beam profiling and also provides both submicron-level high resolution and wide area profiling coverage; and all optical transversal RF filters that operate on the principle of broadband optical spectral control using MEMS and/or Acousto-Optic tunable Filters (AOTF) devices which can provide continuous, digital or hybrid signal time delay and weight selection. The hybrid optical sensors presented in the thesis are extreme environment pressure sensors and dual temperature-pressure sensors. The sensors employ hybrid free-space and fiber-coupled techniques for remotely monitoring a system under simultaneous extremely high temperatures and pressures.Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD
41
Schinkel, Michael. "Nondeterministic hybrid dynamical systems." Thesis, University of Glasgow, 2002. http://theses.gla.ac.uk/1853/.
Full textAbstract:
This thesis is concerned with the analysis, control and identification of hybrid dynamical systems. The main focus is on a particular class of hybrid systems consisting of linear subsystems. The discrete dynamic, i.e., the change between subsystems, is unknown or nondeterministic and cannot be influenced, i.e. controlled, directly. However changes in the discrete dynamic can be detected immediately, such that the current dynamic (subsystem) is known. In order to motivate the study of hybrid systems and show the merits of hybrid control theory, an example is given. It is shown that real world systems like Anti Locking Brakes (ABS) are naturally modelled by such a class of linear hybrids systems. It is shown that purely continuous feedback is not suitable since it cannot achieve maximum braking performance. A hybrid control strategy, which overcomes this problem, is presented. For this class of linear hybrid system with unknown discrete dynamic, a framework for robust control is established. The analysis methodology developed gives a robustness radius such that the stability under parameter variations can be analysed. The controller synthesis procedure is illustrated in a practical example where the control for an active suspension of a car is designed. Optimal control for this class of hybrid system is introduced. It is shows how a control law is obtained which minimises a quadratic performance index. The synthesis procedure is stated in terms of a convex optimisation problem using linear matrix inequalities (LMI). The solution of the LMI not only returns the controller but also the performance bound. Since the proposed controller structures require knowledge of the continuous state, an observer design is proposed. It is shown that the estimation error converges quadratically while minimising the covariance of the estimation error. This is similar to the Kalman filter for discrete or continuous time systems. Further, we show that the synthesis of the observer can be cast into an LMI, which conveniently solves the synthesis problem.
42
Forster, I. "The hybrid electric vehicle." Thesis, Durham University, 1985. http://etheses.dur.ac.uk/9531/.
Full text
43
Bradshaw, William Kenneth. "Control of hybrid machines." Thesis, Liverpool John Moores University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363174.
Full text
44
McLaughlin, Andrew James. "Hybrid silicon optoelectronic technologies." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301855.
Full text
45
Duan, Zhenhua. "Modelling of hybrid systems." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242213.
Full text
46
Bratton, G. J. "Silicate/silicon hybrid materials." Thesis, University of Greenwich, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234283.
Full text
47
Clowes, Darren. "Hybrid semantic-document models." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/14736.
Full textAbstract:
This thesis presents the concept of hybrid semantic-document models to aid information management when using standards for complex technical domains such as military data communication. These standards are traditionally text based documents for human interpretation, but prose sections can often be ambiguous and can lead to discrepancies and subsequent implementation problems. Many organisations produce semantic representations of the material to ensure common understanding and to exploit computer aided development. In developing these semantic representations, no relationship is maintained to the original prose. Maintaining relationships between the original prose and the semantic model has key benefits, including assessing conformance at a semantic level, and enabling original content authors to explicitly define their intentions, thus reducing ambiguity and facilitating computer aided functionality. Through the use of a case study method based on the military standard MIL-STD-6016C, a framework of relationships is proposed. These relationships can integrate with common document modelling techniques and provide the necessary functionality to allow semantic content to be mapped into document views. These relationships are then generalised for applicability to a wider context. Additionally, this framework is coupled with a templating approach which, for repeating sections, can improve consistency and further enhance quality. A reflective approach to model driven web rendering is presented and evaluated. This reflective approach uses self-inspection at runtime to read directly from the model, thus eliminating the need for any generative processes which result in data duplication across source used for different purpose.
48
Abdou, Aly. "Hybrid Group IV nanophotonics." Thesis, Bangor University, 2018. https://research.bangor.ac.uk/portal/en/theses/hybrid-group-iv-nanophotonics(bd04e4dc-5609-408c-b5f6-48a95bac14ff).html.
Full textAbstract:
Advancements in electronic integrated chip technology are slowing down with transistor sizes approaching their theoretical limit in most equipment and devices. As the data transmission rate has benefited from the telecommunication technology through optical fibers, Photonic Integrated Chips (PICs) are expected to fill the gap in the demand for higher transmission rates and faster computational speeds that the electronic chips would fail to fulfill. The research into PICs is in the center of attention in the academic and industrial fields, and the way in front of PICs development and improvement is still long. There are many opportunities including the use of new materials, different designs and architectures, and the use of various physical effects on the macro and micro scales. The main aim of this work is to design a hybrid-multi-layer PIC that allows the integration between an ultra-high-Q micro-resonator made of silica and an optical waveguide of a different material through a MEMS actuated coupler. To date, the ultra-high-Q silica micro-resonators can confine light within for the longest period, which is very beneficial for many applications including revolutionary accurate time measurements, and studying non-linear optical phenomena using modest laser powers. As using silica micro-resonators offers the highest-Q factor, using an optical waveguide of different material can offer the best operation condition based on the required application. For instance, having a silicon waveguide with high refractive index allows the fabrication of dense photonic chips, while using nanocrystalline diamond (NCD) waveguide suits wide-transmission-window applications. To achieve this goal, several studies were required along the way. For example, the hybrid-chip would include a suspended NCD waveguide structure that has not been demonstrated before. So we took the initiative and designed, fabricated and studied its operation. During fabricating the chips in this work, the ablation of NCD films using CO2 laser was observed, which was unexpected. As explanations in the literature was unsatisfactory, we hypothesized a new explanation, and confirmed it using numerical and experimental tests. After designing the hybrid-multi-layer PIC, we took the study a step further and developed the fabrication process. Also, an analytical formula for estimating the scattering loss from asymmetric rough rectangular waveguide surfaces has been formulated to assess the practicality of using specific waveguide designs using certain fabrication techniques. Finally, the design of grating couplers is presented as a starting point for prospective work. The work presented here is believed to be a beneficial milestone in the realisation of practical hybrid multi-layer PICs.
49
Markova, Mariana (Mariana T. ). "Precision hybrid pipelined ADC." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87932.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 205-[208]).
Technology scaling poses challenges in designing analog circuits because of the decrease in intrinsic gain and reduced swing. An alternative to using high-gain amplifiers in the implementation of switched-capacitor circuits has been proposed that replaces the amplifier with a current source and a comparator. The technique has been generalized to zero-crossing based circuits (ZCBC). It has been demonstrated but not limited to single-ended and differential pipelined ADCs, with effective number of bits (ENOB) ranging from 8 bits to 11 bits at sampling rates from 10MS/s to 100MS/s. The purpose of this project was to explore the use of the ZCBC technique for high-precision ADCs. The goal of the project is a 13-bit pipelined ADC operating at up to 100MS/s. A two-phase hybrid ZCBC operation is used to improve the power-linearity tradeoff of the A/D conversion. The first phase approximates the final output value, while the second phase allows the output to settle to its accurate value. Since the output is allowed to settle in the second phase, the currents through capacitors decay, permitting higher accuracy and power-supply rejection compared with standard ZCBCs. Linearization techniques for the ramp waveforms are implemented. Linear ramp waveforms require less correction in the second phase for given linearity, thus allowing faster operation. Techniques for improving linearity beyond using a cascoded current source are explored; these techniques include output pre-sampling and bidirectional output operation. Current steering is used to minimize the overall delay contributing to the first phase error, known as overshoot error. Overshoot error reduction at the end of the first phase improves the linearity requirements of the final phase. Automated background overshoot reduction is introduced though not included on the prototype ADC. A prototype ADC was designed in 1V, 65nm CMOS process to demonstrate the techniques introduced in this work. The prototype ADC did not meet the intended design goal and achieved 11-bit ENOB at 21MS/s and SFDR of 81dB. The main performance limitations are lack of overshoot reduction in the third pipeline stage in the prototype ADC and mid-range errors, introduced by the bidirectional ramp linearization technique, limiting the attainable output accuracy.
by Mariana Markova.
Ph. D.
50
Sfakianakis, Evangelos I. "Hybrid and multifield inflation." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91030.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2014.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references.
In this thesis I study the generation of density perturbations in two classes of inflationary models: hybrid inflation and multifield inflation with non-minimal coupling to gravity. In the case of hybrid inflation, we developed a new method of treating these perturbations that does not rely on a classical trajectory for the fields. A characteristic of the spectrum is the appearance of a spike at small length scales, which could conceivably seed the formation of black holes that can evolve to become the supermassive black holes found at the centers of galaxies. Apart from numerically calculating the resulting spectrum, we derived an expansion in the number of waterfall fields, which makes the calculation easier and more intuitive. In the case of multifield inflation, we studied models where the scalar fields are coupled non-minimally to gravity. We developed a covariant formalism and examined the prediction for non-Gaussianities in these models, arguing that they are absent except in the case of fine-tuned initial conditions. We have also applied our formalism to Higgs inflation and found that multifield effects are too small to be observable. We compared these models to the early data of the Planck satellite mission, finding excellent agreement for the spectral index and tensor to scalar ratio and promising agreement for the existence of iso-curvature modes.
by Evangelos I. Sfakianakis.
Ph. D.