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Dagvadorj, Galbadrakh. "Nonequilibrium BKT transition in microcavity polaritons." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/88602/.
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Bose-Einstein condensation where there is a macroscopic occupation of a single low energy state can occur in three dimensional systems. In two dimensions, a transition of this kind is only possible in the presence of a trap. Instead, for two-dimensional homogeneous systems, the Berezinskii-Kosterlitz-Thouless phase transition is expected, in which a phase transition is mediated by the proliferation of topological defects, governs the critical behavior of a wide range of equilibrium two-dimensional systems with a continuous symmetry, ranging from spin systems to superconducting thin films and two-dimensional Bose fluids, such as liquid helium and ultracold atoms. In this thesis, we show that this phenomenon is not restricted to thermal equilibrium, rather it survives more generally in a dissipative highly nonequilibrium system driven into a steady state. By considering a quantum fluid of polaritons of an experimentally relevant size, in the so-called optical parametric oscillator regime, we demonstrate that it indeed undergoes a phase transition associated with a vortex binding-unbinding mechanism. Yet, the exponent of the power-law decay of the first-order correlation function in the (algebraically) ordered phase can exceed the equilibrium upper limit: this shows that the ordered phase of driven-dissipative systems can sustain a higher level of collective excitations before the order is destroyed by topological defects. Our work suggests that the macroscopic coherence phenomena, observed recently in interacting two- dimensional light-matter systems, result from a nonequilibrium phase transition of the Berezinskii- Kosterlitz-Thouless rather than the Bose-Einstein condensation type.
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Trelcat, Jean-François. "Synthèses par voies solide et hydrothermale pour céramiques de type BNT - BT - BKT." Valenciennes, 2010. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/7f649e27-84b6-4215-952b-cd0b3ee186ad.
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Ce travail a pour objet l’étude de l’un des systèmes les plus prometteurs en tant que substitut au PZT, le ternaire Bi0,5Na0,5TiO3 - BaTiO3 - Bi0,5K0,5TiO3. La première partie de la thèse s’est focalisée sur la synthèse par voie solide de ce système et a permis une estimation plus affinée de la zone de transition de phase morphotropique. Dans une seconde partie, nous nous sommes centrés sur l’élaboration de poudres réactives de BNT par voie hydrothermale. Bien que les divers protocoles mis au point ont permis l’obtention de poudres microniques et cristallisées, toutes se distinguent par l’apparition de phases thermiquement instables en quantités infimes mais néanmoins suffisantes pour entraîner l’apparition d’une macroporosité après frittage. Diverses techniques de lavage ont été développées pour éliminer ces phases métastables. Un compromis a dû être réalisé entre la qualité de l’élimination de ces phases non désirées et le maintien de la composition chimique de la phase majoritaire. Le taux de densification et les propriétés piézoélectriques obtenus sur ces céramiques sont largement comparables à la voie solide. L’étude de la cosynthèse BNT - BT par thermolyse hydrothermale de la composition binaire 0,935 BNT - 0,065 BT n’a pu aboutir et a mis en évidence la précipitation préalable et définitive du titanate de bismuth Bi12TiO20<br>This study focuses on the study of one of the most promising systems as an alternative to PZT, the Bi0,5Na0,5TiO3 - BaTiO3 - Bi0,5K0,5TiO3 ternary system. The first part of the thesis consists on the solid state synthesis of this system and has allowed a more accurate estimation of the morphotropic phase boundary location. In a second part, we focused this study on the development of BNT powders hydrothermal synthesis. Although various protocols have developed the production of fine and single phased powders, all of them are characterized by the presence of thermally unstable phases in minor quantities but nevertheless sufficient to let appear a strong porosity after sintering. Various washing techniques have been developed to eliminate these metastable phases. A compromise between the quality of the metastable phase elimination and the preservation of the major phase chemical composition must be realized. The densification ratio and piezoelectric properties obtained for these ceramics are widely comparable to the solid route synthesized ones. The BNT - BT cosynthesis study of the 0,935 BNT - 0,065 BT binary composition put in evidence the prerequisite and definitive bismuth titanate Bi12TiO20 precipitation
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Faulkner, M. "Topological and emergent phenomena in lattice BKT systems." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1466258/.
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This thesis addresses the emergent electrostatics of two-dimensional, toroidal magnetic models that possess XY symmetry, providing a platform for novel investigations into the Berezinskii-Kosterlitz-Thouless (BKT) phase transition. The BKT transition drives the thermal dissociation of bound pairs of topological defects in many two-dimensional systems, including the two-dimensional XY model of magnetism. The XY model is closely analogous to the two-dimensional Coulomb gas, but can be simulated without computing the long-range interactions of the Coulombic system. This thesis elucidates this paradox by showing that Villain's approximation to the XY model is strictly equivalent to the Maggs-Rossetto (MR) electrostatic model when applied to the two-dimensional Coulomb gas. The mapping is used to probe the BKT transition through the application of the MR algorithm to the two-dimensional Coulomb gas. By simulating the Coulombic system, fluctuations in the winding of charges around the torus are shown to turn on at the BKT transition temperature. These topological-sector fluctuations in the electric field therefore signal the high-temperature phase of the transition. It is then shown that the effective critical exponent of Bramwell-Holdsworth (BH) theory can be measured in superfluid ⁴He films, which correspond to effective Coulomb gases in the limit of large but finite system size. With the Coulombic system taken as the base BKT system, it is inferred that BH theory is a general property of BKT systems.
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Faulkner, Michael. "Phénomènes émergents et topologiques dans les systèmes BKT sur réseau." Thesis, Lyon, École normale supérieure, 2015. http://www.theses.fr/2015ENSL0984/document.
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Cette thèse s'intéresse aux phénomènes électrostatiques émergents dans les modèles magnétiques toroïdaux bi-dimensionnels à symétrie XY, fournissant ainsi un support pour de plus amples recherches dans le domaine de la transition de phase Berezinskii-Kosterlitz-Thouless (BKT).Dans de nombreux systèmes bi-dimensionnels, dont le modèle bi-dimensionnel XY du magnétisme, la transition BKT contrôle la dissociation thermique de paires de défauts topologiques liés. Le modèle XY est analogue au gaz de Coulomb bi-dimensionnel, à ceci près qu'il peut être simulé sans avoir à modéliser les interactions à longue distance du système Coulombien. Cette thèse élucide ce paradoxe en démontrant que l'approximation de Villain appliquée au modèle XY est strictement équivalente au modèle électrostatique de Maggs-Rossetto (MR) appliqué au système Coulombien bi-dimensionnel.Cette équivalence est utilisée pour sonder la transition BKT par l'application de l'algorithme MR au gaz de Coulomb bi-dimensionel. En simulant le système Coulombien, il est prouvé que les fluctuations dans l'organisation des charges autour du tore sont activées à la température de transition BKT. Ces fluctuations du champ électrique indiquent ainsi la phase de haute température de la transition.Il est ensuite montré que l'exposant critique effectif de la théorie de Bramwell-Holdsworth (BH) peut être mesuré dans les films d'hélium 4 superfluide, qui correspondent à des gaz de Coulomb effectifs dans la limite de systèmes de grandes tailles finies<br>This thesis addresses the emergent electrostatics of two-dimensional, toroidal magnetic models that possess XY symmetry, providing a platform for novel investigations into the Berezinskii-Kosterlitz-Thouless (BKT) phase transition.The BKT transition drives the thermal dissociation of bound pairs of topological defects in many two-dimensional systems, including the two-dimensional XY model of magnetism. The XY model is closely analogous to the two-dimensional Coulomb gas, but can be simulated without computing the long-range interactions of the Coulombic system. This thesis elucidates this paradox by showing that Villain's approximation to the XY model is strictly equivalent to the Maggs-Rossetto (MR) electrostatic model when applied to the two-dimensional Coulomb gas.The mapping is used to probe the BKT transition through the application of the MR algorithm to the two-dimensional Coulomb gas. By simulating the Coulombic system, fluctuations in the winding of charges around the torus are shown to turn on at the BKT transition temperature. These topological-sector fluctuations in the electric field therefore signal the high-temperature phase of the transition.It is then shown that the effective critical exponent of Bramwell-Holdsworth (BH) theory can be measured in superfluid 4He films, which correspond to effective Coulomb gases in the limit of large but finite system size. With the Coulombic system taken as the base BKT system, it is inferred that BH theory is a general property of BKT systems
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Cheneau, Marc. "Transition BKT et potentiels géométriques dans le gaz de Bose bidimensionnel." Paris 6, 2009. https://tel.archives-ouvertes.fr/tel-00556002.
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Le travail de thèse exposé dans ce manuscrit porte sur le gaz de Bose bidimensionnel. La première partie présente l'observation de la transition de Berezinskii--Kosterlitz--Thouless dans un gaz de rubidium 87 ultra-froid, confiné dans un piège mixte magnétique et optique. La localisation précise du point critique et la confrontation des données expérimentales à un modèle théorique permettent de clarifier le rôle de l'excitation résiduelle du mouvement axial et l'influence du potentiel de confinement transverse. La deuxième partie décrit le nouveau montage expérimental, sur lequel les prochaines expériences auront lieu. Les premières observations réalisées sur celui-ci concernent l'expansion libre à deux dimensions d'un gaz de rubidium 87 bidimensionnel. Cette expansion se caractérise par une invariance d'échelle, qui révèle la nature des interactions entre atomes. La troisième partie illustre l'utilisation de potentiels géométriques dans un gaz neutre ultra-froid afin de simuler l'action d'un champ magnétique sur des particules chargées. Ces potentiels, associés à la notion de phase de Berry, peuvent être générés par couplage des atomes à un champ laser. Une proposition de réalisation expérimentale devant conduire à la nucléation de vortex est détaillée.
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Zakaria, Rozainah Mohamad. "A demographic study of two wild Arenga palms at Bkt. Lagong Forest Reserve, Selangor, Malaysia." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360720.
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Dang, Suzanne. "Exploration de la transition Berezinskii-Kosterlitz-Thouless avec des excitons dipolaires." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS385/document.
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Ces travaux sont consacrés à l'étude d'un gaz d'excitons bidimensionnel créé dans un double puits quantique de semi-conducteurs. Grâce à un champ électrique appliqué perpendiculairement au plan des puits, les deux composants de l'exciton, l'électron et le trou, sont chacun confinés dans deux puits séparés. Ceci donne lieu à des excitons avec un fort moment dipolaire qui sont piégés et refroidis à très basse température. Dans ce manuscrit, nous étudions les propriétés du gaz d'excitons à travers la photoluminescence émise lors de la recombinaison des paires électron-trou, que nous analysons grâce à des mesures spectroscopiques et interférométriques. Ainsi, nous avons étudié la thermodynamique du gaz d'excitons dans un piège harmonique et établi son équation d'état. Nous avons dévoilé l'universalité de l'équation d'état ce qui a rendu possible la première démonstration de l'équilibre thermodynamique du gaz et a aussi permis d'évaluer la force des interactions entre excitons. En associant des mesures de cohérence spatiale et l'étude de la distribution de défauts de densité dans la photoluminescence des excitons, nous avons montré que dans une zone centrale du piège de rayon R < 3 µm, il s'opère conjointement une augmentation du niveau de cohérence et une diminution de la densité de défauts. Des travaux précédents ayant montré que ces défauts pouvaient constituer des défauts topologiques appelés vortex, nos observations constituent ainsi un ensemble de preuves de l'établissement d'un état superfluide dans la partie centrale du piège, en accord avec la théorie prédite par Berezinskii-Kosterlitz et Thouless<br>This work is devoted to the study of a two dimensional exciton gas created in a semiconductordouble quantum wells. Thanks to an electric field applied perpendicular to these layers,the exciton constituents, namely, the electron and the hole, are confined each in one quantumwell so that excitons inherit a strong electric dipole. In this manuscript, we study the propertiesof such exciton gas trapped at very low temperature, through the photoluminescence emittedby electron-hole recombinations. We particularly study the emitted light using spectroscopic andinterferometric techniques. Thus, we explore the thermodynamics of a trapped gas and quantifyits equation of state. We unveil an important feature: the universality of the equation of state,which allows the first demonstration of thermodynamic equilibrium for excitons, and we realizea direct measurement of the excitons dipolar interaction strength. By probing both the spatialcoherence and the density of defects of the excitons photoluminescence, we show that it exists acentral region (R < 3 μm) in an exciton trap where a high degree of spatial coherence is conditionedby a decrease of the defects density. Our experiments thus provide a set of evidences pointingtowards a Berezinskii-Kosterlitz-Thouless transition for trapped 2D exciton gas
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Yamashita, Kazuya. "Experimental studies of phase coherence of Bose gases in a two-dimensional optical anti-dot lattice." Kyoto University, 2020. http://hdl.handle.net/2433/253382.
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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(人間・環境学)<br>甲第22546号<br>人博第949号<br>新制||人||226(附属図書館)<br>2019||人博||949(吉田南総合図書館)<br>京都大学大学院人間・環境学研究科相関環境学専攻<br>(主査)准教授 木下 俊哉, 教授 吉田 鉄平, 教授 森成 隆夫<br>学位規則第4条第1項該当
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Salomon, Guillaume. "Production tout optique de condensats de Bose-Einstein de 39K : des interactions contrôlables pour l’étude de gaz quantiques désordonnés en dimensions réduites." Thesis, Palaiseau, Institut d'optique théorique et appliquée, 2014. http://www.theses.fr/2014IOTA0009/document.
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Ce travail de thèse rapporte la production tout optique de condensats de Bose-Einstein de 39K. Une étape clé du processus expérimental est l’obtention d’un nuage suffisamment froid permettant le chargement direct d’un piège dipolaire de manière efficace. Notre solution est l’utilisation d’une mélasse fonctionnant dans le bleu de la raie D1 de cet alcalin conduisant à une densité dans l’espace des phases élevée et ainsi au chargement direct d’un grand nombre d’atomes dans un piège à 1550 nm. Le nuage est ensuite polarisé puis comprimé dans un piège dipolaire croisé avant d’entamer un refroidissement évaporatif efficace au voisinage d’une résonance de Feshbach. Ce processus permet la production rapide de condensats de Bose-Einstein toutes les 7 secondes sur notre expérience. Ces nuages dégénérés représentent le point de départ pour la conduite d’expériences visant à étudier les effets du désordre dans les gaz quantiques en dimensions réduites. Nous envisageons l’étude du diagramme de phase du gaz de Bose bidimensionnel désordonné, de la localisation d’Anderson en dimension deux ainsi que l’étude de l’influence du désordre sur un soliton brillant dans une géométrie unidimensionnelle<br>This thesis presents the all optical production of 39K Bose-Einstein condensates. A key point in the process is the sub-Doppler cooling that allows for an efficient loading of an optical dipole trap. To this aim we use a gray molasses scheme working on the blue side of the D1 line of this alkali that leads to a high phase space density and a high number of trapped atoms in a 1550 nm optical trap. The cloud is then polarized and compressed in a crossed dipole trap before starting an efficient forced evaporation close to a Feshbach resonance. This process allows us to produce Bose-Einstein condensates every 7 seconds with our experiment. Those degenerate clouds represent the starting point of experiments aiming to study the influence of disorder on quantum gases in low dimensions. We discuss the perspectives to study of the phase diagram of the two-dimensional disordered Bose gas as well as the Anderson localization phenomenon in two dimensions and the behaviour of bright solitons in a disordered potential in a one-dimensional geometry
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Hurand, Simon. "Contrôle de la supraconductivité à l'interface d'oxydes LaAlO3/SrTiO3 par effet de champ électrique." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066014/document.
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Cette thèse s'intéresse à l'étude de la supraconductivité bidimensionnelle à l'interface entre les oxydes LaAlO3 et SrTiO3 contrôlée par effet de champ électrique. Lorsqu'on fait croître une couche mince de quelques mailles atomiques de LaAlO3 sur un substrat de SrTiO3, l'interface devient conductrice, et même supraconductrice au-dessous de 300mK, bien que ces deux oxydes de structure pérovskite soient des isolants. Il se forme ainsi un gaz bidimensionnel d'électrons de haute mobilité, dont les propriétés - supraconductivité et fort couplage spin-orbite de type Rashba - peuvent être contrôlées par effet de champ électrique à l'aide d'une Back Gate. Nous avons étudié cette supraconductivité bidimensionnelle par trois approches expérimentales différentes : l'étude de la transition supraconductrice en température à l'aide du modèle de Berezinskii-Kosterlitz-Thouless incluant une distribution inhomogène de rigidité ; l'analyse par le groupe de renormalisation de la transition de phase quantique supraconducteur-isolant induite par un champ magnétique perpendiculaire à l'interface selon le modèle de Spivak, Oreto et Kivelson ; et enfin l'étude de l'hystérèse du courant critique ainsi que de sa nature probabiliste dans le cadre du modèle RCSJ. Nous proposons donc de considérer l'interface comme un réseau de flaques supraconductrices couplées par effet Josephson à travers un gaz 2D métallique, dont la transition est régie par le modèle XY des fluctuations de phase. Enfin, nous avons démontré pour la première fois la possibilité de contrôler les propriétés du gaz 2D à l'aide d'une Top Gate, et comparé les effets des deux grilles (Top ou Back Gate)<br>In this PhD work, we study the field-effect modulated two-dimensional superconductivity at the LaAlO3/SrTiO3 oxides hetero-interface. When one grows epitaxially a few unit cells thin film of LaAlO3 on a SrTiO3 substrate, the interface becomes conducting, and even superconducting below 300mK, although these two perovskite oxides are insulators. The properties of this high-mobility two-dimensional electron gas – superconductivity and strong Rashba-type spin-orbit coupling - can be field-effect modulated by the mean of a Back Gate. We have investigated this two-dimensional superconductivity through three different experimental approaches : the temperature-driven transition with the Berezinskii-Kosterlitz-Thouless model including an inhomogeneous distribution of rigidity ; the finite-size scaling analysis of the superconductor-to-insulator quantum phase transition induced by a perpendicular magnetic field using the model developed by Spivak, Oreto and Kivelson ; and finally the measure of the hysteretic and stochastic properties of the critical current in the framework of the RCSJ model. We hence propose to consider this 2D electron gas as an inhomogeneous network of superconducting puddles coupled to one another by Josephson effect through a normal metallic matrix, which transition is dominated by the XY model of the phase fluctuations. Finally, we demonstrated for the first time the possibility of Top Gated-control of this interface, and we investigated the compared effects of Top and Back Gating
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Celtikci, Baris. "Preparation Of Lead-free Bzt-bct Thin Films By Chemical Solution Deposition And Their Characterization." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614623/index.pdf.
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In the presented thesis, lead-free Ba(Ti0.8Zr0.2)O3-(Ba0.7Ca0.3)TiO3 (BZT-BCT) thin films were deposited on Pt/TiO2/SiO2/Si substrates using chemical solution deposition method and then the effect of process parameters were investigated to obtain optimum parameters of these lead-free thin films. The phase was selected near to the morphotropic phase boundary (MPH) to increase the number of polarization directions where rhombohedral and tetragonal phases exist together.
In this study, the effect of sintering temperatures on microstructure, dielectric and ferroelectric properties were studied systematically. Among the various high-quality BZT-BCT thin films with uniform thickness, the optimum dielectric and ferroelectric responses were observed for films annealed at 800 oC for 1 h sintering time. The thickness was kept constant for all measurements as 500 nm (triple layered films). Therefore, the average grain sizes were found around 60 nm for samples sintered at 700,750 and 800 oC.
BZT-BCT thin films sintered at 800 oC showed effective remnant polarization and coercive field values of 2.9 µ<br>C/cm2 and 49.4 kV/cm, together with a high dielectric constant and low loss tangent of 365.6 and 3.52 %, respectively, at a frequency of 600 kHz due to pure perovskite phase showing full crystallization and minimum surface porosity obtained at this temperature.
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Knight, Michael K. "Bit by bit." Claremont Graduate University, 2010. http://ccdl.libraries.claremont.edu/u?/stc,82.
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Malm, Martin. "Beckholmen bit för bit." Thesis, KTH, Arkitektur, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-150351.
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På Beckholmen ligger stockholmsregionens enda aktiva reparationsvarv med kapacitet att ta emot såväl större fartyg samt skärgårdstrafikens fartyg. För att kunna bedriva verksamheten på ett säkert och miljövänligt sätt krävs infrastrukturella investeringar i form av byggnader och anläggningar. Stockholms stad har påbörjat ett programarbete och presenterat ett förslag till detaljplan som möjliggör dessa investeringar. Då det handlar om stora investeringar och förändringar i stadsbilden är den nya detaljplanen ett känsligt projekt, särskilt om varvsverksamheten skulle hamna i ekonomiska svårigheter. I det förslag till detaljplan som presenterats hösten 2012 har varsverksamhetens funktioner lagts inom en och samma byggnadsvolym, som till en följd blir väldigt stor. Frågeställningen i ”Beckholmen bit för bit” är om en detaljplan som låter verksamheten växa mer inkrementellt fördelat på fler byggnader kan göra projektet mer flexibelt. Efter studier av varvsverksamhetens program samt volym och planstudier, blir slutsatsen att det finns fördelar med att fördela varvsfunktionerna på fler byggnadsvolymer. Särskilt om byggnaderna gestaltas på ett sätt så att kompositionen är öppen för förändring. Ett förslag på en gestaltning som uppfyller dessa egenskaper presenteras även.<br>The only active shipyard in the Stockholm region with capacity for large ships and the archipelago fleet is situated at Beckholmen. Large investments in infrastructure and buildings are needed in order to secure the enviroment and worker safety. The city has presented a proposal for new planning enabeling these investments. As the investment are large and the site is sensitive the project has many potential risks, especially if the shipyard should encounter economic difficulties in the future. In the citys planning proposal presented in 2012 the whole program for the shipyard is contained within one single volume. The question at issue in ”Beckholmen bit by bit” thus is if planning that splits the program into separate buildings and permits incremental growth is prefarable. After program studies, volume and plan studies the conclusion is that there are many advantages with planning that encourages incremental growth of the shipyard at Beckholmen, especially if the building design is open to change from the beginning. A proposal of a planning and design fulfilling these qualities is also presented.
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Aoujgal, Ahmed. "Etude des propriétés physico-chimiques et électroniques de matériaux ferroélectriques sous forme de céramiques et de films minces en vue d'applications radiofréquences et microondes." Littoral, 2010. http://www.theses.fr/2010DUNK0285.
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L’objectif du présent travail est de concevoir, réaliser et optimiser des matériaux accordables pour des applications en électronique à hautes fréquences. Le composant le plus simple permettant de mettre à profit cette étude est le condensateur accordable avec une tension continue qui peut être ensuite intégrée dans des dispositifs microondes accordables ou reconfigurables. Le condensteur peut être en couches minces ou en céramique. Pour réaliser de tels composants, on doit utiliser des matériaux présentant de faible pertes diélectriques, une permitivité élevée, une accordabilité importante et une bonne stabilité de la fréquence de résonance avec la température. Pour cela, nous avons mené une étude sur des matériaux ferroélectriques classiques et relaxeurs afin, d’une part d’optimiser les conditions de synthèse, et d’autre part d’améliorer leurs propriétés électriques pour des applications radiofréquences et microondes. Nous avons étudié des matériaux ferroélectriques de phase pérovskite. Il s’agit du titane de baryum et de strontium (BST) qui est un ferroélectrique classique, du titane de baryum et de zircone (BZT) qui selon sa composition peut être classique ou relaxeur et des dérivées du BZT obtenues par substitution au niveau des sites pérovskites a et b respectivement par du bismuth et par du zinc-niobium. Nous avons aussi synthétisé et caractérisé des matériaux de phase pyrochlore de formule Bi1. 5ZnNb1. 5O7. Ces études vont de l’élaboration de tous ces matériaux sous forme de céramiques et de couches minces, suivies de caractérisations physico-chimiques, structurales, diélectriques et ferroélectriques dans une large gamme de fréquences et de températures<br>The main objective of this work is to design, implement and optimize tunable materials for electronic applications at high frequencies. The easiest component to build on this study is the tunable capacitor with a voltage which can then be integrated into microwave devices such as tunable or reconfigurable resonators, filters, antennas. . . Etc. The capacitor can be either thin film or ceramic-based. To produce such components we must use materials which must have low dielectric loss, high dielectric permittivity, high tunability and stability of the resonant frequency of the capacitor with the temperature. For this, we conducted a detailed study of classical and relaxor ferroelectric materials in order, firstly to optimize the synthesis conditions, and secondly to improve their electrical properties for radiofrequencies and microwave applications. We have studied ferroelectric materials with perovskite phase, namely barium titanate strontium (BST) which is a classical ferroelectric and barium zirconium (BZT) which according to its composition can be a classical ferroelectric or relaxor ferroelectric and the derivatives of BaZr0. 1Ti0. 9O3 obtained by substituting bismuth and zinc-niobium respectively at A and B sites of the perovskite phase. We also synthesized and characterized the pyrochlore phase materials of bismuth zinc niobate, with composition of Bi1. 5ZnNb1. 5O7. The studies we have done range from the development of these materials in the form of ceramics and thin films, followed by characterizations to determine their physico-chemical properties, structural dielectric and ferroelectric in a range wide of frequencies and temperature
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Redinger, Petra Best Troy L. "Variation in populational size and composition within two summer colonies of endangered gray bats (Myotis grisescens)." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Spring/master's/REDINGER_PETRA_52.pdf.
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Rivera, Marcos D. ""Scary but a Little Bit Motivating": Understanding the Lived Experiences of Academic Probation and Deciding to Participate in an Academic Intervention Program." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu155500243951416.
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Hoesel, Stan van. "De constructie van de informatiesnelweg "bit by bit" /." [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Maastricht University [Host], 2001. http://arno.unimaas.nl/show.cgi?fid=13064.
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Vivian, Darlan. "Ariadne-BFT." Florianópolis, SC, 2007. http://repositorio.ufsc.br/xmlui/handle/123456789/90028.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.<br>Made available in DSpace on 2012-10-23T05:20:15Z (GMT). No. of bitstreams: 1
240731.pdf: 888300 bytes, checksum: 247a9d9a95ae0d19f44c9efcd4411b18 (MD5)<br>As redes sem fio ad hoc surgiram para estender a mobilidade e a flexibilidade no ambiente sem fio, onde um conjunto de nós, que podem agir como roteadores, formam a infra-estrutura de roteamento na rede. A maioria dos protocolos de roteamento propostos não utiliza mecanismos de segurança, pois assumem que o ambiente é composto apenas por nós confiáveis. Mas devido à mudança dinâmica de topologia e ambiente aberto, uma rede ad hoc é extremamente vulnerável à presença de nós maliciosos os quais podem degradar desempenho ou até mesmo impedir o funcionamento da rede. Para evitar ou minimizar os problemas causados pela falta de segurança, os seguintes protocolos de roteamento seguro foram propostos: Ariadne, SAODV, BFTR, SEAD e ARAN. Neste contexto, a presente dissertação tem como objetivo analisar estes protocolos de roteamento seguro utilizados em redes sem fio ad hoc e propor melhorias nos mecanismos de segurança projetados para proteger a rede contra ataques interrupção de roteamento e de consumo de recursos. Como resultado desta análise, é proposto o Ariadne-BFT (Ariadne Best-effort Fault-Tolerant), uma extensão do protocolo de roteamento seguro Ariadne baseado nos algoritmos de descoberta e seleção de rotas do protocolo BFTR. O Ariadne-BFT incrementa a segurança no roteamento em relação ao protocolo Ariadne original, com a proteção contra o ataque Blackhole. Experimentos são executados sob a forma de simulações para análise e comparação de desempenho, através das quais é demonstrado que o protocolo Ariadne-BFT possui um desempenho superior em relação às métricas latência e razão de entrega de pacotes.
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Abreu, Victor Vicente. "Balance-bot." Master's thesis, Universidade da Madeira, 2009. http://hdl.handle.net/10400.13/59.
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Research on inverted pendulum has gained momentum over the last decade on a number
of robotic laboratories over the world; due to its unstable proprieties is a good example
for control engineers to verify a control theory. To verify that the pendulum can
balance we can make some simulations using a closed-loop controller method such as
the linear quadratic regulator or the proportional–integral–derivative method.
Also the idea of robotic teleoperation is gaining ground. Controlling a robot at a
distance and doing that precisely. However, designing the tool to takes the best benefit
of the human skills while keeping the error minimal is interesting, and due to the fact
that the inverted pendulum is an unstable system it makes a compelling test case for
exploring dynamic teleoperation.
Therefore this thesis focuses on the construction of a two-wheel inverted pendulum
robot, which sensor we can use to do that, how they must be integrated in the system
and how we can use a human to control an inverted pendulum.
The inverted pendulum robot developed employs technology like sensors, actuators and controllers. This Master thesis starts by presenting an introduction to inverted pendulums and some information about related areas such as control theory. It continues by describing related work in this area. Then we describe the mathematical model of a two-wheel inverted pendulum and a simulation made in Matlab. We also focus in the construction of this type of robot and its working theory. Because this is a mobile robot we address the theme of the teleoperation and finally this thesis finishes with a general conclusion and
ideas of future work.<br>Orientador: Ian Oakley
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Caputo, Robert Thomas. "Bat parts." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4586.
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Moen, Selmer, and Charles Jones. "BIT RATE AGILITY FOR EFFICIENT TELEMETRY." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/606754.
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International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>The Bit Rate Agile Onboard Telemetry Formatting (BRAOTF) system was developed by Killdeer Mountain Manufacturing to address increasing demands on the efficiency of telemetry systems. The BRAOTF thins and reorders data streams, adjusting the bit rate of a pulse code modulation (PCM) stream using a bit-locked loop to match the desired information rate exactly. The BRAOTF accomplishes the adjustment in hardware, synthesizing a clock whose operating frequency is derived from the actual timing of the input format. Its firmware manages initialization and error management. Testing has confirmed that the BRAOTF implementation meets its design goals.
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Karaer, Arzu. "Optimum bit-by-bit power allocation for minimum distortion transmission." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4760.
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In this thesis, bit-by-bit power allocation in order to minimize mean-squared error (MSE) distortion of a basic communication system is studied. This communication system consists of a quantizer. There may or may not be a channel encoder and a Binary Phase Shift Keying (BPSK) modulator. In the quantizer, natural binary mapping is made. First, the case where there is no channel coding is considered. In the uncoded case, hard decision decoding is done at the receiver. It is seen that errors that occur in the more significant information bits contribute more to the distortion than less significant bits. For the uncoded case, the optimum power profile for each bit is determined analytically and through computer-based optimization methods like differential evolution. For low signal-to-noise ratio (SNR), the less significant bits are allocated negligible power compared to the more significant bits. For high SNRs, it is seen that the optimum bit-by-bit power allocation gives constant MSE gain in dB over the uniform power allocation. Second, the coded case is considered. Linear block codes like (3,2), (4,3) and (5,4) single parity check codes and (7,4) Hamming codes are used and soft-decision decoding is done at the receiver. Approximate expressions for the MSE are considered in order to find a near-optimum power profile for the coded case. The optimization is done through a computer-based optimization method (differential evolution). For a simple code like (7,4) Hamming code simulations show
that up to 3 dB MSE gain can be obtained by changing the power allocation on the
information and parity bits. A systematic method to find the power profile for linear block codes is also introduced given the knowledge of input-output weight enumerating function of the code. The information bits have the same power, and parity bits
have the same power, and the two power levels can be different.
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Sandvik, Jørgen Moe. "En variabel bit lengde 9-bit 50MS/S SAR ADC." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20654.
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A 9-bit 50MS/s SAR ADC with a simulated power consumption of 24.5 µW was designed for this thesis. Speci&#64257;cations were made for application with in-probe electronic as part of an ultrasound system. A novel switching-scheme - employing variable bit length encoding – was introduced in order to simplify successive approximation. Pre-layout results reported a FoM of just 1.37 fJ/conversion step, which is favorable to all published designs to date. Recent technology advancements has seen the ultrasound &#64257;eld expanding into handheld markets [33]. More power e&#64259;cient solutions, in addition to existing enhanced resolution 3-D technology both place strict requirements for analog/mixed-signal design. Composite electronics within the probe casing - allowing close-to-source signal processing - is believed to be the future of ultrasound devices. ADC designs suitable for in-probe technology require ultra low power and noise characteristics towards supporting multiple channels on a single SoC. Excellent performance of recent SAR ADCs make them a viable alternative for in-probe technology [2,7,12,4]. Work in this thesis show the &#64258;exibility of the SAR algorithm. The relatively simple implementation/decoding of the VBL approach, complimented by the accuracy dependency of the level detection range makes the ADC recon&#64257;gurable by digital signal processing. Recent published design has reported relatively low power consumption for the comparator [15,7]. A motivation for the thesis was to see whether multiple operated comparators could reduce power in remaining circuitry. Implementation of a level-detector - supporting the VBL switching-scheme - has lead to improvements in: Power e&#64259;ciency, speed and metastability-induced errors. The device consists of two comparators operated in parallel, with a relative DC-o&#64256;set generated by di&#64256;erence in the capacitive load. Decision points of the comparators shift with DC-o&#64256;set, and are atoned for a range desired by the modi&#64257;ed SAR algorithm. An extensive literary search of recent methodologies and results was conducted, and a summery presenting state-of-the-art designs is included with the work. An approach using no external references where chosen as a basis for the DAC design. Emphasize was made on constant common-mode voltage suitably for comparator design eliminating pre-ampli&#64257;ers or bu&#64256;ers. Digital logic consisting of serial connected bitslices using a novel di&#64256;erential approach is proposed. Level detector outputs are connected to the digital logic switching only a portion of transistors in the bitslice during conversion. Trade-o&#64256; between switching activity and circuit area proves e&#64256;ective, with only 12.5% of overall power consumed in the digital part. Power simulations reported the level-detector as the dominant source of consumption, thereby being subject to further optimization with regards to power. Nonetheless a proof-of-concept 8-bit ADC implementation - operated with the novel switching-scheme - produced 8.96 ENOB while dissipating less power.
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James, Calvin L. "ENHANCE BIT SYNCHRONIZER BIT ERROR PERFORMANCE WITH A SINGLE ROM." International Foundation for Telemetering, 1990. http://hdl.handle.net/10150/613417.
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International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>Although prefiltering prevents the aliasing phenomenon with discrete signal processing, degradation in bit error performance results even when the prefilter implementation is ideal. Degradation occurs when decisions are based on statistics derived from correlated samples, processed by a sample mean estimator. i.e., a discrete linear filter. However, an orthonormal transformation can be employed to eliminate prefiltered sample statistical dependencies, thus permitting the sample mean estimator to provide near optimum performance. This paper will present mathematical justification for elements which adversely affect the bit synchronizer’s decision process and suggest an orthonormal transform alternative. The suggested transform can be implemented in most digital bit synchronizer designs with the addition of a Read Only Memory (ROM).
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Li, Fangyan. "Simulation multi-moteurs multi-niveaux pour la validation des spécifications système et optimisation de la consommation." Thesis, Nice, 2016. http://www.theses.fr/2016NICE4008/document.
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Ce travail vise la modélisation au niveau système, en langage SystemC-AMS, et la simulation d'un émetteur-récepteur au standard Bluetooth Low Energy (BLE). L'objectif est d'analyser la relation entre les performances, en termes de BER et la consommation d'énergie du transceiver. Le temps de simulation d’un tel système, à partir de cas d’étude (use case) réaliste, est un facteur clé pour le développement d’une telle plateforme. De plus, afin d’obtenir des résultats de simulation le plus précis possible, les modèles « haut niveau » doivent être raffinés à partir de modèles plus bas niveau où de mesure. L'approche dite Meet-in-the-Middle, associée à la méthode de modélisation équivalente en Bande Base (BBE, BaseBand Equivalent), a été choisie pour atteindre les deux conditions requises, à savoir temps de simulation « faible » et précision des résultats. Une simulation globale d'un système de BLE est obtenue en intégrant le modèle de l'émetteur-récepteur dans une plateforme existante développée en SystemC-TLM. La simulation est basée sur un système de communication de deux dispositifs BLE, en utilisant différents scénarios (différents cas d'utilisation de BLE). Dans un premier temps nous avons modélisé et validé chaque bloc d’un transceiver BT. Devant le temps de simulation prohibitif, les blocs RF sont réécrits en utilisant la méthodologie BB, puis raffinés afin de prendre en compte les non-linéarités qui vont impacter le couple consommation, BER. Chaque circuit (chaque modèle) est vérifié séparément, puis une première simulation système (point à point entre un émetteur et un récepteur) est effectuée<br>This work aims at system-level modelling a defined transceiver for Bluetooth Low energy (BLE) system using SystemC-AMS. The goal is to analyze the relationship between the transceiver performance and the accurate energy consumption. This requires the transceiver model contains system-level simulation speed and the low-level design block power consumption and other RF specifications. The Meet-in-the-Middle approach and the Baseband Equivalent method are chosen to achieve the two requirements above. A global simulation of a complete BLE system is achieved by integrating the transceiver model into a SystemC-TLM described BLE system model which contains the higher-than-PHY levels. The simulation is based on a two BLE devices communication system and is run with different BLE use cases. The transceiver Bit-Error-Rate and the energy estimation are obtained at the end of the simulation. First, we modelled and validated each block of a BT transceiver. In front of the prohibitive simulation time, the RF blocks are rewritten by using the BBE methodology, and then refined in order to take into account the non-linearities, which are going to impact the couple consumption, BER. Each circuit (each model) is separately verified, and then a first BLE system simulation (point-to-point between a transmitter and a receiver) has been executed. Finally, the BER is finally estimated. This platform fulfills our expectations, the simulation time is suitable and the results have been validated with the circuit measurement offered by Riviera Waves Company. Finally, two versions of the same transceiver architecture are modelled, simulated and compared
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Tölch, Ulf. "Bat Time Stories." Diss., lmu, 2006. http://nbn-resolving.de/urn:nbn:de:bvb:19-51308.
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Barrett, Janine. "Australian bat lyssavirus /." St. Lucia, Qld, 2004. http://adt.library.uq.edu.au/public/adt-QU20040729.134623/index.html.
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Sullivan, Lawrence. "Bat Problem Management." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/146697.
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Schmidt-Jortzig, Immo Joachim. "Ermittlungskompetenzen des BKA." Frankfurt, M. Berlin Bern Bruxelles New York, NY Oxford Wien Lang, 2009. http://d-nb.info/995123667/04.
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Scharroba, Anika. "Small but powerful." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17798.
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In der vorliegenden Arbeit wurden die Einflüsse der landwirtschaftlichen Nutzung auf die Struktur und Biomasse von Nematoden entlang eines Tiefengradientens und innerhalb zweier Vegetationsperioden an einem Ackerstandort untersucht. Die Freilandanalyse der Nematodengemeinschaft wies auf ein mit Nährstoffen angereichertes und gestörtes Ökosystem, mit einer geringen Diversität, hin. Entlang des Tiefengradienten bildeten die Nematoden Metacommunities, welche Umweltgegebenheiten wie Nahrungsquellen und abiotischen Faktoren widerspiegeln. Signifikant höhere Biomassen wurden unter Weizen im Vergleich zu Mais als Ackerfrucht beobachtet. Die Streuapplikation induzierte einen „bottom-up“ Effekt mit größeren Biomassen in den niedrigen als in den höheren trophischen Stufen. Die Nematoden Biomassen sowie die faunistischen Indizes (Channel Index, Enrichment Index) zeigten, dass der Kohlenstofffluss im Bakterienkanal des Bodens dominierte. Allerdings deckte das 13C Pulse-Labelling Experiment im Feld auf, dass der Kohlenstofffluss durch die Pilzgemeinschaft sowie die pilzfressenden Nematoden wesentlich höhere Umsatzraten aufweist. In einem 14C-Laborexperiment wurde ein vollständiges Budget des Flusses von wurzelbürtigem Kohlenstoff in das Nahrungsnetz der Nematoden bestimmt. Hierbei wiesen die pflanzenparasitären Nematoden die höchsten 14C-Gehalte innerhalb weniger Tage auf, da sie direkt an den Wurzeln fressen und über die Herbivorenkette den Nährstoffzyklus im Boden eröffnen.<br>The present research considered the effects of agricultural management practice on the nematode community structure and biomass in three different depths and two successive vegetation periods at an arable field site. The resource quality was manipulated by crop plant and organic amendment, to investigate the major soil carbon pathways based on roots, bacteria and fungi. The nematode community analysis pointed to a highly enriched and disturbed ecosystem with low biodiversity. Along the depth gradient the nematodes formed distinct metacommunities, reflecting resource availability and abiotic environmental factors. Wheat supported significantly greater nematode biomass than maize. The litter amendment induced bottom-up effects, with greater biomass allocation at lower than at higher trophic levels. The biomass of nematode families as well as faunal indices (Channel Index, Enrichment Index) revealed a predominance of the bacterial carbon channel in the arable soil. A 13C pulse-labelling experiment investigating the flux of root- derived C into the soil food web revealed high turnover rates in the fungal carbon pathway. This was evident for soil fungi as well as for fungal-feeding nematodes and contradicts general assumptions of a more active bacterial pathway in arable soils. A laboratory experiment with 14C isotope was used to compile a complete budget for the root-derived carbon in the nematode food web. Here plant-feeding nematodes, which feed on living plant roots, thereby opening the root C cycling into the food web, showed highest amounts of 14C allocation within a few days.
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Segars, Tara. "8-Bit Hunger." Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1619176909244462.
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Seidman, Brian H. "And Nothing But." Miami University / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=miami1058824897.
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Bonaiuti, Davide. "Progettazione e sviluppo di un'applicazione per la gestione degli appuntamenti tra professionisti e clienti." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11865/.
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Tutti coloro che lavorano su appuntamento hanno una clientela da gestire. Per farlo, possono avvalersi di due opzioni: o utilizzano una buona parte del loro tempo per rispondere direttamente alle chiamate e ai messaggi dei clienti, oppure assumono una persona che si faccia carico personalmente dell’agenda del negozio, piuttosto che dello studio, a seconda dei casi.
Gli aspetti negativi di queste due scelte non mancano. Nel primo caso, il diretto interessato può trovarsi interrotto da una chiamata nel pieno di un appuntamento. Il cliente lì presente deve attendere pazientemente che la conversazione finisca, ma la pazienza, giustamente, inizia a vacillare nel momento in cui le chiamate diventano numerose. Oltretutto la situazione può creare disagio al professionista in prima persona. In alcuni casi, inoltre, il cliente a casa è costretto ad aspettare tempi troppo lunghi prima di ricevere una risposta. Nel secondo caso, si ha un lavoro più fluido e senza interruzioni. Questo è ovviamente un fattore positivo, tuttavia l’assunzione di un addetto a rispondere al telefono, piuttosto che a messaggi o mail, ha un costo non indifferente.
Analizzando i vari vantaggi e svantaggi dei metodi di prenotazione esistenti, è stata progettata una nuova soluzione che, tramite l'utilizzo dei bot e delle app di messaggistica, permette di prendere gli appuntamenti rimanendo il più fedeli possibile ai metodi classici, come i messaggi, ma con tutti i vantaggi dei metodi più tecnologici.
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Gilani, Syed Zafar ul Hussan. "Understanding the behaviour and influence of automated social agents." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/279022.
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Online social networks (OSNs) have seen a remarkable rise in the presence of automated social agents, or social bots. Social bots are the new computing viral, that are surreptitious and clever. What facilitates the creation of social agents is the massive human user-base and business-supportive operating model of social networks. These automated agents are injected by agencies, brands, individuals, and corporations to serve their work and purpose; utilising them for news and emergency communication, marketing, social activism, political campaigning, and even spam and spreading malicious content. Their influence was recently substantiated by coordinated social hacking and computational political propaganda. The thesis of my dissertation argues that automated agents exercise a profound impact on OSNs that transforms into an array of influence on our society and systems. However, latent or veiled, these agents can be successfully detected through measurement, feature extraction and finely tuned supervised learning models. The various types of automated agents can be further unravelled through unsupervised machine learning and natural language processing, to formally inform the populace of their existence and impact.
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Näslund, Mats. "Bit extraction, hard-core predicates and the bit security of RSA." Doctoral thesis, KTH, Numerical Analysis and Computer Science, NADA, 1998. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-2687.
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Xiao, Xin, Bane Vasic, and Shu Lin. "MULTI-BIT BIT-FLIPPING ALGORITHM FOR COLUMN WEIGHT-4 LDPC CODES." International Foundation for Telemetering, 2017. http://hdl.handle.net/10150/627015.
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Low-density parity-check (LDPC) codes with column weight-4 are widely used in many commu-nication and storage systems. However, traditional hard decision decoding algorithms such as the bit-flipping (BF) algorithm suffer from error floor due to trapping sets in LDPC codes. In this paper, to lower error floor of the BF algorithm over the Binary Symmetric Channel (BSC), we design a set of decoding rules incorporated within the BF algorithm for column weight-4 LDPC codes. Given a column weight-4 LDPC code, the dominate error patterns of the BF algorithm are first specified, and according to the designed rules, additional bits at both variable nodes (VN) and check nodes (CN) provide more information for the BF algorithm to identify the dominate error patterns, so that the BF algorithm could deliberately flip some bits to break them. Simulation results show that the modified BF algorithm eliminates all 4-error patterns and lowers the Bit Error Rate (BER) for at least two orders of magnitude with a trivial increment of complexity.
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Hirt, Samuel James Best Troy L. "Analysis of stable isotopes of hydrogen to determine migrational source of silver-haired bats (Lasionycteris noctivagans) in Alabama." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Biological_Sciences/Thesis/Hirt_Samuel_52.pdf.
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CHAKRABORTY, S. K., and R. K. RAJANGAM. "PROGRAMMABLE HIGH BIT RATE FRAME SYNCHRONISER." International Foundation for Telemetering, 1989. http://hdl.handle.net/10150/614490.
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International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California<br>The first Indian Remote Sensing Satellite was launched on 17th March 1988 from a Soviet Cosmodrome into a 904 Km Polar Sunsynchronous orbit. The data transmission from the satellite is at 5.2 Mega Bits/sec in S-Band and 10.4 Mega Bits/sec in X-Band. The payload data is formatted into custom made 8328 words format. A programmable unique versatile frame sync and Decommutation unit has been developed to test the data from the data handling system during its various phases of development. The system works upto 50 Mega Bits/sec and can handle frame sync code length upto 128 bits and a frame length of 2 Exp 20 bits. Provision has been made for programming the allowable bit errors as well as bit slippages, using a front panel setting. This paper describes the design and implementation of such a high bit rate frame synchroniser developed specially for IRS Spacecraft application. It will also highlight the performance of the system.
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Köhlmoos, Melanie. "Bet-El - Erinnerungen an eine Stadt Perspektiven der alttestamentlichen Bet-El-Überlieferung." Tübingen Mohr Siebeck, 2006. http://deposit.ddb.de/cgi-bin/dokserv?id=2773069&prov=M&dok_var=1&dok_ext=htm.
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吳景濤 and King-to Ng. "A novel bit allocation buffer control algorithm for low bit-rate videocompression." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31221518.
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Zimic, Sheila. "Internetgenerationen bit för bit : Representationer av IT och ungdom i ett informationssamhälle." Doctoral thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-21926.
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The aim of this thesis is to gain a deeper understanding in relation to the construction of a ‘Net Generation’. With regards to the idea of an information society, technologies and young people are given certain positions, which are not in any sense natural but are socially constructed. This thesis explores these socially given meanings and shows what types of meanings are prioritized and legitimized. The exploration is conducted by examining, both externally and internally, given meanings of a generation identity. The external (nominal identification) in this study is understood as the construction of an abstract user and is studied by means of academic texts concerning the ‘Net Generation’. The internal (virtual identification) involves young people’s construction of their generation identity and is studied by means of collage. The collages are used to understand how the young participants position themselves in contemporary society and how they, as concrete users, articulate their relationship with information technologies. The findings show that the ‘type of behavior’ which is articulated in the signifying practice of the construction of the abstract user, ‘Net Generation’, reduces users and technology to a marketing / economical discourse. In addition the idea of the abstract user implies that all users have the same possibilities to achieve ‘success’ in the information society, by being active ‘prosumers’. The concrete users articulate that they feel stressed and pressured in relation to all the choices that they are expected to make. In this sense, the participants do not articulate the (economical) interests as assumed for the ‘Net Generation’, but, rather articulate interests to play, to have a hobby and be social when using information technologies. What this thesis thus proposes, is to critically explore the ‘taken for granted’ notions of a technological order in society as pertaining to young people. Only if we understand how socially given meaning is constructed can we break loose from the temporarily prioritized values to which the position of technology and users are fixed.
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Simón, Gallego Carlos. "Bit-Torrent in Erlang." Thesis, Uppsala University, Department of Information Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-98284.
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<p>The goal of my project has been to programme a Bit-torrent application using Erlang language. A Bit-Torrent application permits the user to download files from the system and share files at the same time. The reason Erlang was chosen is because this programming language has suitable features for concurrency and distributed system.</p><p>The most important aspect I have considered in my project has been to manage a proper behaviour of the system, more than the simply fact of transferring stuff. This way, the program will be able to response to changes immediately. The changes could be: a user uploads a new file to share with other peers, a file is removed, new chunks of a file appear… and others like that.</p><p>My Bit-Torrent system contains five modules: Bittorrent, Tracker, Statistic, Server and User module, and all of them will be explained going into details in this document.</p>
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Vogt, Isabelle. "“Born in Africa but...”." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-103684.
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Blankenship, Cecil, Bill Garris, Mary Langenbrunner, Teresa Brooks Taylor, and Teresa Brooks Taylor. "I’m Not Prejudiced, But…" Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/3636.
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Baier, Uwe [Verfasser]. "BWT tunneling / Uwe Baier." Ulm : Universität Ulm, 2021. http://d-nb.info/122799530X/34.
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Nesbitt, Robyn. "Not today, but tomorrow." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/10651.
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Includes bibliographical references.<br>'Not today, but tomorrow', the title of this body of work, references a collection of daily lists I assembled during my first year of the Masters of Fine Arts (MFA) programme. I had written 'not today but tomorrow' on one of my Monday lists and that was all. It seems a fitting description and context for this body of work as I try to hold on to the moment, today, in anticipation of what is yet to come, tomorrow.
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Danielsson, Petra. "Same same, but different." Thesis, Malmö högskola, Fakulteten för kultur och samhälle (KS), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-22979.
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Det senaste året har matsvinn som orsakas på grund av att frukter och grönsaker medskönhetsfel slängs uppmärksammats. Uppsatsen undersöker vad man kan tänka på vidframställning av säljbudskap där frukter och grönsaker med abnorma former är i fokus. Hurkan det framgå att det är ett allvarligt budskap och hur får man konsumenter att tilltalas avinnehållet? Vilka teoretiska utgångspunkter finns det för formgivandet av någontingnormavvikande, för att inge förtroende hos de som är möjliga konsumenter?Målet med undersökningen är att, utifrån retoriska och semiotiska teorier och metoder, tareda på om det finns några likheter i utformningen av annonser vars avsikt är att sälja dessaråvaror. För en så rättvis och likgiltig granskning som möjligt av analysmaterialet kommerannonserna från likartade avsändare och medier.Resultatet av undersökning visar att ett antal likheter finns i bildanvändningen, i takt medatt de vill bidra till en positiv attityd gentemot råvarorna i fråga. I förhållande till demresonerar jag kring huruvida mitt designprojekt hade gynnats av att genomgå en liknandeanalys i designprocessens slutskede.<br>The past year, food wastage caused due to fruits and vegetables with blemishes have been highlighted. The essay explores what designers can have in mind at preparation of sales messages, in which fruits and vegetables with abnormal forms are in focus. How will it communicate that there is a serious message and how to get consumers to be addressed by the content? What theoretical approaches can designers relate to while creating standard deviant ads, to inspire those who are potential consumers? The goal of the survey is that, based on rhetorical and semiotic theories and practices, is to find out if there are any similarities in the design of advertisements whose intention is to sell these commodities. To make the analysis as fair and indifferent as possible the material are from similar senders and medias.The result of the survey shows that there are a number of similarities in image usage, alongside that they want to contribute to a positive attitude towards the raw materials in question. In relation to the similarities, the study discusses whether my design project had benefited from undergoing a similar analysis during the final stage of the design process.
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Landrum-Bittles, Jenita. "Confined, but not contained." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1327690698.
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Grayson, Neil R. "The Bit - Collected Stories." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555428898931184.
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Burgess, George, and Lloyd Bridges. "Single Board Bit Synchronizer." International Foundation for Telemetering, 1989. http://hdl.handle.net/10150/614628.
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International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California<br>ASIC developments have made it possible to include the essential signal processing functions for data detection, clock recovery, and NCO in a single custom-designed chip. Using this chip and PLDs enabled the implementation of a fully-featured bit synchronizer on a single VME board in a rack-mountable 1.75" high, 19" wide chassis. This represents a space savings of 2/3 over existing units. The data rates supported are 250 bps to 5Mbps (2.5 Mbps biphase).