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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Design considerations for high speed clock and data recovery circuits /

Beshara, Michel, January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2002. / Includes bibliographical references (p. 93-95). Also available in electronic format on the Internet.
232

Σχεδίαση ολοκληρωμένων κυκλωμάτων επικοινωνιών, πολύ υψηλών συχνοτήτων

Κορκοτσίδης, Στέλιος 21 December 2012 (has links)
Στα πλαίσια της παρούσας διπλωματικής εργασίας μελετήθηκαν οι βασικές αρχές λειτουργίας και θορύβου στα Phase Locked Loops. Στη συνέχεια σχεδιάστηκε το σχηματικό και το layout ενός PLL μικτού σήματος στο λογισμικό σχεδίασης ολοκληρωμένων κυκλωμάτων, Cadence IC5141. Το κύκλωμα αυτό λειτουργεί σαν συνθέτης συχνοτήτων στην περιοχή των 5GHz, από μία συχνότητα αναφοράς 50MHz, έχει θόρυβο φάσης περίπου 88dBc στο 1MHz από το φορέα και μέση κατανάλωση λιγότερο από 30mW. / Analysis of basic operation principles and noise performance of Phase Locked Loops. Design of a PLL (schematic and layout) in Cadence IC5141.
233

Adapting the polytope model for dynamic and speculative parallelization / Adaptation du modèle polyhédrique à la parallélisation dynamique et spéculatice

Jimborean, Alexandra 14 September 2012 (has links)
Dans cette thèse, nous décrivons la conception et l'implémentation d'une plate-forme logicielle de spéculation de threads, ou fils d'exécution, appelée VMAD, pour "Virtual Machine for Advanced Dynamic analysis and transformation", et dont la fonction principale est d'être capable de paralléliser de manière spéculative un nid de boucles séquentiel de différentes façons, en ré-ordonnançant ses itérations. La transformation à appliquer est sélectionnée au cours de l'exécution avec pour objectifs de minimiser le nombre de retours arrières et de maximiser la performance. Nous effectuons des transformations de code en appliquant le modèle polyédrique que nous avons adapté à la parallélisation spéculative au cours de l'exécution. Pour cela, nous construisons au préalable un patron de code qui est "patché" par notre "runtime", ou support d'exécution logiciel, selon des informations de profilage collectées sur des échantillons du temps d'exécution. L'adaptabilité est assurée en considérant des tranches de code de tailles différentes, qui sont exécutées successivement, chacune étant parallélisée différemment, ou exécutée en séquentiel, selon le comportement des accès à la mémoire observé. Nous montrons, sur plusieurs programmes que notre plate-forme offre de bonnes performances, pour des codes qui n'auraient pas pu être traités efficacement par les systèmes spéculatifs de threads proposés précédemment. / In this thesis, we present a Thread-Level Speculation (TLS) framework whose main feature is to speculatively parallelize a sequential loop nest in various ways, to maximize performance. We perform code transformations by applying the polyhedral model that we adapted for speculative and runtime code parallelization. For this purpose, we designed a parallel code pattern which is patched by our runtime system according to the profiling information collected on some execution samples. We show on several benchmarks that our framework yields good performance on codes which could not be handled efficiently by previously proposed TLS systems.
234

Sistema de reconhecimento de padrÃes para identificaÃÃo de porte de veÃculos atravÃs de anÃlise de perfil magnÃtico / A Pattern recognition system for identification of vehicles by analysis of magnetic profile

Herivelton Alves de Oliveira 08 September 2011 (has links)
Atualmente os ÃrgÃos de trÃnsito utilizam os sistemas de monitoramento de trÃfego para reduÃÃo de acidentes de trÃnsito e como ferramenta fundamental para a coleta de dados estatÃsticos para auxiliar no planejamento e gerenciamento dos sistemas viÃrios. Nestes dados sÃo observadas informaÃÃes como a quantidade de veÃculos que trafegam em determinado ponto, a velocidade mÃdia e a identificaÃÃo da categoria dos veÃculos. A identificaÃÃo da categoria dos veÃculos que trafegam em uma via permite o controle de acesso a faixas de rolagem destinadas a uma classe de veÃculos especÃfica. O objetivo desse trabalho à propor uma soluÃÃo para classificaÃÃo de veÃculos atravÃs da anÃlise de sinais coletados de sensores indutivos no momento em que o veÃculo passa sobre os mesmos. O conjunto destes sinais para cada veÃculo à denominado perfil magnÃtico. Foi utilizado um classificador baseado em Rede Neural Artificial (RNA) para identificar o tipo de veÃculo de acordo com o padrÃo do perfil magnÃtico coletado. Na implementaÃÃo do sistema foi utilizado um framework Java que possibilitou a integraÃÃo da RNA ao aplicativo que opera no equipamento de monitoramento de trÃfego. TambÃm foi desenvolvido um aplicativo em Java que permite realizar o treinamento da rede utilizando dados coletados no equipamento e tambÃm permite avaliar posteriormente os resultados obtidos pela RNA. Os veÃculos foram classificados nas seguintes categorias: motos, veÃculos pequenos, veÃculos mÃdios, Ãnibus e caminhÃes. O sistema desenvolvido foi integrado a um equipamento de fiscalizaÃÃo de trÃfego fabricado pela empresa Fotosensores e apresentou resultados satisfatÃrios, pois o Ãndice de acerto geral do classificador foi de 97%, alÃm de representar uma melhoria no equipamento que anteriormente realizava a classificaÃÃo em somente quatro classes de veÃculos. / Currently, transit agencies use traffic monitoring systems to reduce traffic accidents and as a fundamental tool for collecting statistical data for planning and management of road systems. These data are observed as the amount of information vehicles that travel at a certain point, the average speed and the identification of the category of vehicles. The identification of the category of vehicles that travels on a path allows you to control access lanes connecting to a specific class of vehicles. The objective of this work is to propose a solution for vehicle classification by analyzing signals collected from inductive sensors at the time the vehicle passes over the sensors. This set of signs for each vehicle is called the magnetic profile. This work used a classifier based on Artificial Neural Network (ANN) to identify the type of vehicle according to the pattern of magnetic profile collected. The implemented system used a Java framework that enabled the integration of ANN to the application that operates in the traffic monitoring equipment. It was developed a Java application that trains the ANN using data collected in the equipment and also allows evaluating further classification results obtained by the ANN. The vehicles were classified into the following categories: motorcycles, small vehicles, medium vehicles, buses and trucks. The developed system has been integrated into a traffic monitoring equipment manufactured by Fotosensores and gave satisfactory results with an overall success rate above 97%. It represents an improvement in the equipment that carried out the classification.
235

Análise de explosões solares em 45 e 90 GHz observadas por POEMAS com medidas de polarização

Silva, Douglas Félix da 28 January 2016 (has links)
Made available in DSpace on 2016-03-15T19:35:58Z (GMT). No. of bitstreams: 1 Douglas Felix da Silva.pdf: 5938737 bytes, checksum: aa521c46d45966ffa8b9f1f8067be11c (MD5) Previous issue date: 2016-01-28 / Fundação de Amparo a Pesquisa do Estado de São Paulo / Solar flares are characterized by a sudden release of energy, of magnetic origin, that accelerates particles producing emission throughout the entire electromagnetic spectrum and plasma heating. It is believed that a fraction of these accelerated particles are injected into bipolar magnetic fields. Radiation from these events at radio wavelengths is due to the acceleration of the energetic particles that spiral around magnetic loops. Thus masurements of right and left circularly polarized brightness temperature of three flares at the frequencies of 45 and 90 GHz yield degrees of circular polarization that reached 5 to 40 % and were opposites at 45 and 90 GHz, always being reversed for the events. The interpretation of these results may be associated with the asymmetry of the field strength of magnetic loop legs. The objective of this work is to study the magnetic field configuration and energy distribution of accelerated particles in solar flares. For the study of these solar flares, we use the observations of the telescopes POEMAS (POlarization Emission of Millimeter Solar Activity), that monitor the Sun at 45 and 90 GHz with circular polarization. Observations in radio were complemented with microwaves, using data from the Radio Solar Telescope Network (RSTN) at 1-15 GHz, and high frequency emission, at 212 and 405 GHz, observed by the Solar Submillimeter Telescope (SST). X-ray data were obtained from FERMI and RHESSI telescopes; and the Solar Dynamics Observatory (SDO) provided images at 171 Å and magnetograms of the active regions. To study the interaction between the particles and magnetic field we applied the model developed by Simões (2009). Numerical simulations were performed and produced sources at 45 and 90 GHz in a three dimensional magnetic loop with maximum intensity in opposite polarities of a dipole loop. The simulations also reproduced the degree of polarization and radio spectra observed in each event. Thus, by means of the simulations, we obtained the location of 45 and 90 GHz sources with predominant intensities in opposite magnetic polarities and with reversed degree of polarization. / A explosão solar é caracterizada por uma súbita liberação de energia, de origem magnética, a qual acelera as partículas produzindo emissão em todo o espectro eletromagnético e promovendo o aquecimento do plasma. Acredita-se que uma fração destas partículas não térmicas aceleradas são injetadas em campos magnéticos bipolares. A emissão de radiação proveniente dos eventos na faixa rádio é devida à aceleração das partículas energéticas associada ao movimento em espiral que fazem em torno dos arcos magnéticos. Medidas de temperatura de brilho circularmente polarizada à direita e à esquerda em três explosões solares nas frequências de 45 e 90 GHz apresentaram graus de polarização circular que alcançaram de 5 a 40 % e opostos em 45 e 90 GHz, sempre sendo invertidos para os eventos estudados. Uma interpretação desses resultados pode estar associada com a assimetria de intensidade do campo nos pés do arco magnético. O objetivo do trabalho é estudar a configuração do campo magnético e a distribuição de energia das partículas aceleradas em explosões solares na faixa rádio. Para o estudo das explosões, utilizamos as observações do sistema de telescópios POEMAS (POlarização da Emissão Milimétrica da Atividade Solar), que monitora o Sol em 45 e 90 GHz com medidas de polarização. As observações em rádio foram complementadas em micro-ondas, utilizando os dados da Rede de Radio Telescópios Solares (RSTN), de 1 a 15 GHz, e em altas frequências (212 e 405 GHz) pelo Telescópio Solar Submilimetrico (SST). Na faixa de raio X foram utilizados dados dos telescópios FERMI e RHESSI; enquanto do Solar Dynamics Observatory (SDO) foram obtidas imagens em 171 Å e magnetogramas das região ativas. Para estudar a interação entre as partículas e campo magnético foi aplicado o modelo desenvolvido por Simões (2009). Foram realizadas simulações numéricas que produziram fontes em 45 e 90 GHz num arco magnético em três dimensões, cujas fontes apresentaram máximos de intensidade em polaridades opostas de um arco dipolar. As simulações também reproduziram qualitativamente o grau de polarização observado em cada um dos eventos e também o espectro rádio. Assim, por meio da simulação, obtivemos as possíveis localizações das fontes em 45 e 90 GHz com intensidades predominantes em polaridades opostas e grau de polarização invertido.
236

Monitoramento hidrossedimentológico numa bacia hidrográfica do Escudo Sul-Rio-Grandense / Hydrosedimentological monitoring in catchment from Sul-RioGrandense shield

Bartels, Guilherme Kruger 30 April 2015 (has links)
Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2016-04-08T19:47:07Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Monitoramento hidrossedimentológico numa bacia hidrográfica do escudo sul-rio-grandense.pdf: 3298608 bytes, checksum: 197f42a8c4f63d0217bc52c6db4902f1 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-04-08T19:47:19Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Monitoramento hidrossedimentológico numa bacia hidrográfica do escudo sul-rio-grandense.pdf: 3298608 bytes, checksum: 197f42a8c4f63d0217bc52c6db4902f1 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-04-08T19:47:29Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Monitoramento hidrossedimentológico numa bacia hidrográfica do escudo sul-rio-grandense.pdf: 3298608 bytes, checksum: 197f42a8c4f63d0217bc52c6db4902f1 (MD5) / Made available in DSpace on 2016-04-08T19:47:39Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Monitoramento hidrossedimentológico numa bacia hidrográfica do escudo sul-rio-grandense.pdf: 3298608 bytes, checksum: 197f42a8c4f63d0217bc52c6db4902f1 (MD5) Previous issue date: 2015-04-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A construção e uso de redes de monitoramento hidrossedimentológicas, são extremamente importantes para compreensão da dinâmica dos fenômenos envolvidos, chuva, vazão e produção de sedimentos. O monitoramento hidrossedimentológico realizado para descrever e compreender o transporte e a produção de sedimentos em uma bacia hidrográfica. Assim o objetivo deste trabalho foi analisar relações entre os processos hidrossedimentológicos numa bacia hidrográfica rural, utilizando técnicas de monitoramento. O trabalho foi realizado na bacia hidrográfica do Arroio do Ouro, localizada entre os municípios de Pelotas e Morro Redondo/RS, com área de 17,17km2, elevação média de 194 metros, predominância de relevo ondulado. Os usos predominantes do solo são das atividades desenvolvidas em pequenas propriedades familiares, observando-se o cultivo de espécies como pêssego, milho e tabaco, além de atividades de pecuária leiteira e avicultura. O monitoramento hidrossedimentológico contínuo teve início em 2014, com sensores de precipitação (pluviógrafos), sensor de pressão (nível) e sensor de turbidez (turbidímetro). Durante o período de monitoramento de 6 meses (abril a outubro de 2014) foram monitorados 13 eventos de precipitação, com diferentes características e em diferentes condições de uso e manejo do solo. Os resultados demonstram que a produção de sedimento tem relação direta com a magnitude dos eventos de precipitação, na qual um evento extremo foi responsável pelo transporte de 1.335,58 toneladas de sedimento, correspondendo a 59,4% da produção total de sedimentos de todos os eventos monitorados. O sedimento transportado em arraste representou de 9 a 43,8% do total de sedimento transportado, destacando sua importância do transporte em arraste no Arroio do Ouro. O laço de histerese não apresentou predominância em um único sentido, observando-se eventos com sentido horário e anti-horário. No entanto os eventos que apresentaram histerese anti-horária foram caracterizados por serem de pequena magnitude, nestes eventos é possível que ocorra a deposição de sedimento na calha fluvial, limitados ao transporte de sedimento proveniente de áreas mais distantes como é o característico deste tipo de histerese. / The construction and the use of hydrosedimentological monitoring networks, are extremely important for the comprehension of the dynamics of phenomena involved, e.g. rain, discharge and sediment production. The hydrosedimentological monitoring is realized to describe and understand the transport and production of sediment in one catchment. Therefore the objective of this work was to analyze the relationship between the hydrosedimentological processes in one rural catchment, using monitoring techniques. This work was developed in the Arroio do Ouro catchment, situated between Pelotas and Morro Redondo/RS, with a drainage area of 17,27km², with average elevation of 194 meters, and undulating relief predominant. The soil uses are destined to activities in small farms, observing the cultivate of peach, corn and tobacco, apart from activities of livestock milk and aviculture. The continuous hydrosedimentological monitoring began in the beginning of 2014, with precipitation sensors (rain gauges), pressure sensors (pressure-sensing limnograph), and turbidity sensors (turbidity meter).During the 6-month monitoring period (April to October, 2014) 13 precipitation events were monitored, with different features and different condition of use and management. The results demonstrate that the sediment production has a direct relation with the magnitude of the precipitation events, in which one of these events was responsible for the transport of 1335,58 tons of sediment, corresponding to 59,4% of the total production of sediments of the all monitoring events. The bedload transported represented from 9 to 43,8% of the total of sediment rate, highlighting the importance of the total bedload in Arroio do Ouro. The hysteretic loops did not produce predominance of one type of way, presenting clockwise and counter-clockwise events. However, the events which presented counter-clockwise hysteretic loops were characterized by the lower magnitude. In these events it is possible the occurence of sediment deposition in the river channel, limited to transport of sediment from more distant areas, as it is typical in this type of hysteretic loops.
237

Exploring the use of a digital audio workstation and tangible controllers to democratize musical expression among children with motor disabilities

Knutsson, Marcus January 2017 (has links)
There is a lot of research connecting musical expression with well-being, motivation and meaningfulness, especially when introduced in early years. Children should have the opportunity to express themselves through music regardless of motor disability. There is research targeting children with motor disabilities and musical expression but when the projects ends the children are left without the technology. There is a gap in research exploring technologies accessible in terms of availability to buy and use for the children. This thesis take advantage of the evolution of music production technologies where standard digital audio workstations are highly customizable and therefore an option to use as tools to democratize musical expression among children with motor disabilities. Democratize in this context means to make the children able to participate in a musical performance and express themselves in a similar way as fully abled children. To explore the use of music production technologies to promote musical expression among children with motor disabilities a proposed solution of digital audio workstation Ableton Live and beat matched functionalities coupled with various tangible controllers was explored during 3 sessions at a school in Malmö. Four children at the age of 10 with motor disabilities participated together with their music teacher. The result indicates that the proposed solution has great potential to democratize musical expression among the children using available music production technology. The key component in the proposed prototype was the use of beat matched loops and effects which were synchronized to the songs tempo and made it possible for the children to express themselves musically.  The result also show that an important aspect of gaining well-being, motivation and meaningfulness among the children was connected to the proposed prototype ability to generate a musical outcome matching the children's expectations and personal preferences.
238

Disruption-free routing convergence : computing minimal link-state update sequences / Convergence du routage sans perturbation : calcul de séquences minimales de mises à jour d’états des liens

Clad, François 22 September 2014 (has links)
Avec le développement des applications temps-réel sur Internet, telles que la télévision, la voix sur IP et les jeux en ligne, les fournisseurs d'accès à Internet doivent faire face à des contraintes de plus en plus fortes quant aux performances de leurs services. Cependant, après chaque changement topologique, les protocoles de routage à état des liens, utilisés dans les réseaux de cœur de ces opérateurs, entrent dans une période de convergence durant laquelle des boucles de routage peuvent apparaître. Ce phénomène dégrade les performances du réseau (latence, congestions, pertes de paquets) et peut durer plusieurs secondes. Dans le cadre de cette thèse, nous proposons de nouvelles solutions permettant de prévenir ces perturbations dans le cas de reconfigurations sur un lien ou un routeur. Notre approche a pour particularité de ne reposer que sur les mécanismes de base des protocoles de routage à état des liens, et d’être ainsi déployable de manière incrémentale dans n’importe quel réseau. Intuitivement, il s’agit de contrôler implicitement l’ordre de mise à jour des routeurs, à travers une modification progressive du poids d’un sous-ensemble de liens. Par exemple, l’augmentation du poids d’un lien aura pour effet de forcer les routeurs les plus éloignés de ce composant à se mettre à jour avant les routeurs plus proches. En adaptant finement l’amplitude de tels changements, il est alors possible de répartir la mise à jour de routeurs potentiellement impliqués dans une boucle sur plusieurs étapes. Cette opération peut ensuite être répétée jusqu’à ce que le composant ne soit plus utilisé pour acheminer des données dans le réseau, permettant un retrait sans impact sur le routage. / The use of real time media or mission critical applications over IP networks is making strong pressure on service providers to operate disruption free networks. However, after any topological change, link-state Interior Gateway Protocols (IGPs), such as IS-IS or OSPF, enter a convergence phase during which transient forwarding loops may occur. Such loops increase the network latency and cause packet losses for several seconds. In this thesis, we propose and evaluate innovative solutions to prevent these perturbations in case a planned modification on a link or a router. Our approach only relies on core functionalities of link-state routing protocols, thus being incrementally deployable in any network. Intuitively, it consists in implicitly controlling the routers update order through successive IGP weight reconfigurations on a subset of links. For example, progressively increasing the weight of a link forces farthest routers to update their routes first, before closest ones. Hence, finely tuning such changes may allow to spread the update of routers potentially implied in a loop across multiple steps. This operation can be repeated until the component to be removed is no longer used to forward traffic in the network, thus allowing its removal with no impact on the routing decisions.
239

Etude par simulations de dynamique des dislocations des effets d'irradiation sur la ferrite à haute température / Study by dislocation dynamics simulations of radiation effects on the plasticity of ferrite at high temperature

Shi, Xiangjun 01 December 2014 (has links)
Cette étude s’insère dans le cadre d’une modélisation multi-échelles du durcissement et de la fragilisation par irradiation de l’acier de cuve des Réacteurs nucléaires à Eau Pressurisée (REP). Des simulations en Dynamique des Dislocations (DD) ont été menées pour décrire la plasticité du fer pur irradié à l’échelle du grain et fournir aux échelles supérieures des informations quantitatives telles que la force d’épinglage des dislocations par les boucles induites par l’irradiation. Nous avons débuté notre étude par l’analyse des interactions élémentaires entre une dislocation coin et différents types de boucles. Un nouveau modèle de DD a été identifié puis validé, que ce soit d’un point de vue qualitatif (mécanismes d’interaction) ou quantitatif (contrainte critique), en comparant ces résultats à ceux obtenus en Dynamique Moléculaire dans la littérature. L’influence de la taille des boucles et de la vitesse de déformation a été particulièrement étudiée.Des simulations élémentaires impliquant cette fois-ci une dislocation vis et les mêmes défauts d’irradiation ont permis d’étendre le domaine de validité du modèle de DD, en se comparant toujours aux résultats de DM de la littérature. Enfin, un premier jeu de simulations massives entre une dislocation coin et différents types de boucles a permis d’obtenir une première estimation de la valeur de la force d’obstacle pour ce type de défauts, α≈0,26. Cette valeur est en accord avec différents travaux précédents, expérimentaux ou numériques, et permet d’envisager avec confiance de futurs travaux s’appuyant sur ce nouveau modèle de DD. / This study is a contribution to the multi-scale modeling of hardening and embrittlement of the vessel steel in Pressurized Water Reactors (PWR) under irradiation conditions. Dislocation Dynamics simulations (DD) were conducted to describe the plasticity of irradiated iron at grain scale. Quantitative information about the pinning strength of radiation-induced loops was extracted and can be transferred at crystal plasticity scale. Elementary interactions between an edge dislocation and different types of loops were first analyzed. A new model of DD was identified and validated, both qualitatively in terms of interaction mechanisms and quantitatively in terms of critical stress, using Molecular Dynamics results available in the literature. The influence of the size of the loops and of the strain rate was particularly studied. Elementary simulations involving a screw dislocation and the same radiation-induced defects were conducted and carefully compared to available MD results, extending the range of validity of our model. Finally, a set of massive simulations involving an edge dislocation and a large number of loops was performed and allowed a first estimation of the obstacle strength for this type of defects (α≈0.26). This value is in a good agreement with previous experimental and numerical studies, and gives us confidence in future work based on this new DD model.
240

The impact of the integrated stress response on DNA replication

Choo, Josephine Ann Mun Yee 12 December 2019 (has links)
No description available.

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