906 resultados para New Space Vector Modulation


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A DSP implementation of Space Vector PWM (SVPWM) using constant V/Hz control for the open winding doubly-fed generator is proposed. This control of SVPWM modulation mode and open winding structure combination has the high voltage utilization ratio, greatly improves the control precision of the system, and reduces the stator winding output current distortion rate, though the complexity of the system is increased. This paper describes the basic principle of SVPWM and discusses the particularity of SVPWM waveform generated by hybrid vector under the condition of open winding. This method is applied to a state of doubly-fed wind power generator. The experimental verification shows that this control method can make the output voltage amplitude of the doubly-fed induction generator be 380V and the frequency be 50Hz by using of TMS32028335 chip based on constant V/Hz control of symmetric SVPWM modulation wave.

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Este estudo centra-se numa investigação sobre o conceito de trabalho em open space na nova sede no Porto da empresa Energias de Portugal - SA, tendo em conta a estratégia implementada e os resultados conseguidos. Para isso, dissecámos as premissas apresentadas aos trabalhadores na cerimónia de inauguração do novo espaço - “O Open Space opera como plataforma de comunicação e de partilha de informação” e “O Open Space responde às necessidades dos trabalhadores, criando ambientes de trabalho modernos e funcionais”. A fim de avaliarmos o campo empírico, construímos e enviámos em formato eletrónico para o e-mail de todos os trabalhadores da amostra um instrumento de medida que denominámos de open space (OS). As ilações retiradas estão baseadas nos resultados analisados e discutidos após processamento em SPSS - predictive analytics software and solutions e em reports gráficos. O open space da EDP Porto é um local moderno e funcional, privilegiado em relação à fluidez e partilha de informação, capaz de manifestar estratégias de negócio e de salientar aspetos da marca e da cultura da Empresa. A formação/informação sobre comportamentos e regras básicas a seguir na partilha de um mesmo espaço, as razões de negócio que levam a organização a mudar o espaço de trabalho, a par das vantagens que ambas as partes podem tirar do novo conceito, influencia positivamente ou negativamente a perceção da mudança e o estado emocional dos trabalhadores. O ruído, a temperatura ambiente, a concentração ou a privacidade, são alguns dos fatores que poderão variar com o layout e funcionam como condicionantes de uma maior ou menor satisfação ambiental. No entanto, existem sempre questões que permanecem pendentes e foi nesse contexto que deixámos algumas propostas para novas investigações num trabalho científico que nunca se esgota. / This study focuses on researching the concept of working in an open space in the new Oporto’s headquarters of the company Energias de Portugal - SA, given the strategy implemented and the results achieved. For this, we dissected the assumptions presented to workers at the inauguration ceremony of the new space - "The Open Space operates as a platform for communication and information sharing" and "The Open Space responds to the needs of workers, creating modern and functional workplaces". In order to evaluate the empirical side, we built and sent, in electronic format, an e-mail to all the workers of the sample with a measurement tool that we called the open space (OS). The conclusions are based on the results analyzed and discussed after being processed in SPSS - predictive analytics software and solutions and graphs in reports. The open space of the EDP Oporto is a modern and functional place, privileged in relation to fluidity and information sharing, capable of manifesting business strategies and highlight aspects of the brand and culture of the Company. The training/information on behaviors and basic rules to follow when sharing the same space, the business reasons that lead the organization to change the workspace, along with the advantages that both parties can benefit from the new concept, influence positively or negatively the perception of change and the emotional state of workers. Noise, temperature, concentration or privacy, are some of the factors that may vary with the layout and function as constraints in a greater or lesser environmental satisfaction. However, there are always issues that remain outstanding and it was in this context that we made some proposals for further research in a scientific paper that never runs out.

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The voltage source inverter (VSI) and current voltage source inverter (CSI) are widely used in industrial application. But the traditional VSIs and CSIs have one common problem: can’t boost or buck the voltage come from battery, which make them impossible to be used alone in Hybrid Electric Vehicle (HEV/EV) motor drive application, other issue is the traditional inverter need to add the dead-band time into the control sequence, but it will cause the output waveform distortion. This report presents an impedance source (Z-source network) topology to overcome these problems, it can use one stage instead of two stages (VSI or CSI + boost converter) to buck/boost the voltage come from battery in inverter system. Therefore, the Z-source topology hardware design can reduce switching element, entire system size and weight, minimize the system cost and increase the system efficiency. Also, a modified space vector pulse-width modulation (SVPWM) control method has been selected with the Z-source network together to achieve the best efficiency and lower total harmonic distortion (THD) at different modulation indexes. Finally, the Z-source inverter controlling will modulate under two control sequences: sinusoidal pulse width modulation (SPWM) and SVPWM, and their output voltage, ripple and THD will be compared.

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The reconstruction of physical environments of Amazonian areas is of great interest to determine the dynamic evolution of the Amazon drainage basin. However. few studies have emphasized the Quaternary deposits in this region. which is mostly due to the lack of natural exposures imposed by the low topography. This work integrates facies analysis. radiocarbon dating, delta(13)C, delta(15)N, and C/N of an 124 m-thick core from an area located at the mouth of the Amazon River. northeastern Amazonia. The study records deposits up to 50.795 (14)C yr B P. in age. which formed in a variety of depositional environments including fluvial channel, tidal flat, outer estuarine basin to shallow marine. inner estuarine basin, estuarine channel and lagoon. Facies interpretation was significantly improved with the inclusion of delta(13)C, delta(15)N, and C/N analyses of organic matter extracted from the sediments The obtained values conform to a transitional. mostly estuarine paleosetting evolved during successive relative sea-level fluctuations. The results suggest fluvial deposition between 40,950 (+/- 590) and 50.795 (14)C yr B P, with a rise in relative sea level that commenced between 35,567 (+/- 649) and 39,079 (+/- 1114) (14)C yr B P. An overall transgression took place until 29,340 (+/- 340) (14)C yr B P., after which the relative sea level dropped, favoring valley rejuvenation and incision. Following this time up to 10,479 (+/- 34) (14)C yr B.P. a rise in relative sea level filled up the valley with estuarine deposits After 10.479(+/- 34) (14)C yr B.P., the estuary was replaced by a lagoon At the end of the Holocene, the coastline prograided approximately 45 km northward, replaci ng the lagoon by a lake system Despite the influence of eustatic fluctuations. regional tectonics played a significant role to create new space where these Late Pleistocene and Holocene sediments accumulated. (C) 2009 Elsevier B V All rights reserved.

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Relatório de Estágio para obtenção de grau de Mestre em Engenharia Civil Perfil de Edificações

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Relatório da Prática Profissional Supervisionada Mestrado em Educação Pré-Escolar

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Dissertação de mestrado integrado em Engenharia Civil

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Background: Nitric oxide (NO) has been largely associated with cardiovascular protection through improvement of endothelial function. Recently, new evidence about modulation of NO release by microRNAs (miRs) has been reported, which could be involved with statin-dependent pleiotropic effects, including anti-inflammatory properties related to vascular endothelium function. Objective: To evaluate the effects of cholesterol-lowering drugs including the inhibitors of cholesterol synthesis, atorvastatin and simvastatin, and the inhibitor of cholesterol absorption ezetimibe on NO release, NOS3 mRNA expression and miRs potentially involved in NO bioavailability. Methods: Human umbilical vein endothelial cells (HUVEC) were exposed to atorvastatin, simvastatin or ezetimibe (0 to 5.0 μM). Cells were submitted to total RNA extraction and relative quantification of NOS3 mRNA and miRs -221, -222 and -1303 by qPCR. NO release was measured in supernatants by ozone-chemiluminescence. Results: Both statins increased NO levels and NOS3 mRNA expression but no influence was observed for ezetimibe treatment. Atorvastatin, simvastatin and ezetimibe down-regulated the expression of miR-221, whereas miR-222 was reduced only after the atorvastatin treatment. The magnitude of the reduction of miR-221 and miR-222 after treatment with statins correlated with the increment in NOS3 mRNA levels. No influence was observed on the miR-1303 expression after treatments. Conclusion: NO release in endothelial cells is increased by statins but not by the inhibitor of cholesterol absorption, ezetimibe. Our results provide new evidence about the participation of regulatory miRs 221/222 on NO release induction mediated by statins. Although ezetimibe did not modulate NO levels, the down-regulation of miR-221 could involve potential effects on endothelial function.

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Ante el nuevo reto que supone la adaptación al Espacio Europeo de Educación Superior (EEES) con una acción política que propone introducir importantes modificaciones en la concepción del proceso de enseñanza-aprendizaje entre las que se encuentran el replanteamiento del papel del profesor y del alumno, y el proceder metodológico en la acción docente, todos los agentes educativos deben aunar esfuerzos para articular medidas que posibiliten la adaptación a este nuevo escenario de manera óptima. Las universidades están ofreciendo a los docentes herramientas que puedan facilitar el acceso a los procesos de innovación educativa que exige el nuevo espacio de formación. En este marco es donde nace el proyecto titulado 'Programa de Introducción a la Investigación y al Desarrollo de las Destrezas Comunicativas (hablar y escribir correctamente)' que, valiéndose de los recursos tecnológicos que nos ofrece el Servicio de Innovación Educativa de la Universidad de Málaga, busca mejorar las competencias de expresión oral y escrita de los alumnos, así como la capacidad para organizar sus trabajos de investigación de manera rigurosa y ordenada, siguiendo una secuenciación razonada y científica. En la presente comunicación se detallan los objetivos del proyecto, la descripción del mismo, el modo de proceder en su desarrollo, las partes de las que ha constado y las conclusiones a las que se ha llegado.

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Implantació d¿una botiga online de llibres, modernitzant la nostra actual. Ambaquest nou espai, es pretén oferir un producte atractiu per a qualsevol client, que li permetrà realitzar laseva compra des de qualsevol part del mon

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Partiendo de la idea ampliamente aceptada de que las TIC (Tecnologías de Información y Comunicación) han tenido una profunda influencia en los modos en que la sociedad contemporánea experimenta y concibe las nociones de espacio y tiempo, y sustentándose en el contexto de la importancia adquirida por dichas nociones en la comprensión de los procesos sociales en general y estéticos en particular, esta investigación ha tenido por objetivo analizar la espacio-temporalidad en el contexto específico de la era digital. Poniendo en relación la fenomenología de los dispositivos tecnológicos con las nuevas estrategias de representación y puesta en imagen del espacio y el tiempo, nuestro propósito ha sido mostrar no sólo cómo a través de las prácticas artísticas digitales puede identificarse y analizarse el imaginario espacio-temporal de la era digital, sino también cómo éstas –basadas en una larga trayectoria estética de intersecciones entre arte y tecnología- han revestido al espacio y al tiempo de nuevas fenomenologías posibles, dando lugar a nuevas formas de percibirlos y cumpliendo, por tanto, un papel activo en la configuración de dicho imaginario y sus sucesivas transformaciones. La perspectiva teórica adoptada para esta investigación parte de las teorías postmodernas del espacio y el tiempo –considerando autores como Harvey o Jameson-, recurriendo a la sociología del Imaginario Social desarrollada por Castoriadis, Castro-Nogueira o J. L. Pintos para comprender cómo el espacio y el tiempo adquieren significaciones particulares. Combinando estas bases teóricas con los estudios visuales y los trabajos de teóricos de los medios como McLuhan, De Kerckhove o Lev Manovich, se establecerían las posibles relaciones entre las tecnologías, las representaciones sociales del espacio y el tiempo – analizadas a partir de metáforas como “compresión espacio-temporal”, “espacio de los flujos” o “tiempo atemporal” y sus relaciones con el Ciberespacio- y la fenomenología espacio-temporal de las prácticas artísticas y sus estrategias de representación visual –tomando como objeto de estudio tipologías artísticas que van desde el Hipercine a la Realidad Virtual y Aumentada, los Medios Locativos o la Telepresencia. La conclusión que hemos podido extraer de este estudio es que si bien distintos tipos de tecnologías afectan operacional y perceptivamente a la construcción social de la espacio-temporalidad, los modos en que estas tecnologías han estetizado la propia realidad y los modos en que condicionan la construcción estética de las nociones de espacio y tiempo, tanto a partir de la propia fenomenología del dispositivo como de la experimentación creativa con el mismo, ejercen una profunda influencia sobre el imaginario social y espacio-temporal propios de la era digital.

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A statistical method for classification of sags their origin downstream or upstream from the recording point is proposed in this work. The goal is to obtain a statistical model using the sag waveforms useful to characterise one type of sags and to discriminate them from the other type. This model is built on the basis of multi-way principal component analysis an later used to project the available registers in a new space with lower dimension. Thus, a case base of diagnosed sags is built in the projection space. Finally classification is done by comparing new sags against the existing in the case base. Similarity is defined in the projection space using a combination of distances to recover the nearest neighbours to the new sag. Finally the method assigns the origin of the new sag according to the origin of their neighbours

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We study dynamics of domain walls in pattern forming systems that are externally forced by a moving space-periodic modulation close to 2:1 spatial resonance. The motion of the forcing induces nongradient dynamics, while the wave number mismatch breaks explicitly the chiral symmetry of the domain walls. The combination of both effects yields an imperfect nonequilibrium Ising-Bloch bifurcation, where all kinks (including the Ising-like one) drift. Kink velocities and interactions are studied within the generic amplitude equation. For nonzero mismatch, a transition to traveling bound kink-antikink pairs and chaotic wave trains occurs.

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Työn tavoitteena oli tutkia Etelä-Karjalan keskussairaalaan mahdollisesti perustettavan yhdistelmätarkkailuosaston kannattavuutta määrittämällä osaston kustannukset ja hyödyt. Määritettyjen kustannusten avulla vertailtiin päivystys-potilaiden eri hoitoketjuvaihtoehtoja. Lähdeaineistona työssä käytettiin sairaalan omia materiaaleja ja tilastoja, henkilöstön haastatteluja sekä muita kirjallisuuslähteitä. Kirjallisuuden mukaan sairaalan ylikuormitus johtuu sen huonosta potilasvirtojen kulusta, jota voidaan parantaa joko toimintaa tehostamalla tai investoimalla uusiin resursseihin. Eräs vaihtoehto ylikuormituksen purkuun on tarkkailuosaston perustaminen, joka ei ole vain lisätila vaan potilasvirtojen ohjauskeino. Tehtyjen laskemien mukaan Etelä-Karjalan keskussairaalan tarkkailuosasto vaikuttaisi kannattavalta. Tarkkailuosaston kustannukset vuodessa olisivat 1 099 745 €, tuotot 1 170 108 € ja voitto 70 363 €. Osaston perustamiskustannukset olisivat 950 324 €. Hoitoketjujen potilaskohtaisen kannattavuuden mukaan päivystyspotilaiden tarkkailu ja lyhytaikainen hoito kannattaisi tehdä joko vuodeosastoilla tai tarkkailuosastolla, mutta ei tappiota tuottavalla ensiapupoliklinikalla. Tarkkailuosastosta olisi taloudellisten tekijöiden lisäksi myös muita hyötyjä ja haittoja sairaalan sidosryhmille. Sairaalan valitsemasta ylikuormituksen vähentämiskeinosta riippumatta, on sen tärkeätä aloittaa jo lähivuosina valmistautuminen väestön ikääntymisen aiheuttamaan lisääntyvään kuormitukseen.

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Työssä johdettiin sähköisen lineaariservomoottorijärjestelmän dynaaminen malli. Lineaarimoottori on keksintönä vanha, mutta vasta viimeaikoina kestomagneettimateriaalien kehittyessä ja halvetessa lineaarimoottorista on tullut varteenotettava vaihtoehto pyörivän moottorin ja lineaarisen liikkeen toteuttavan mekanismin yhdistelmälle. Kestomagnetoituja lineaarimoottoreita käytetään sovelluksissa, joissa tarvitaan tarkkaa paikoitusta ja nopeudella ja kiihtyvyydellä on suuret vaatimukset. Moottorimalli toteutettiin vuorovaikutteisena simulointimallina. Moottorimalli, josta saatiin moottorin voima, rakennettiin MatLabâ 6.0/Simulinkâ –ohjelmalle ja moottoriin kiinnitetyn mekaniikan malli ADAMS 10.0 –ohjelmalle. Mallit on liitetty tämän jälkeen vuorovaikutteiseksi simulointimalliksi. Simuloinnista saatuja tuloksia on verrattu koneautomaation laboratorioon hankitun lineaarimoottorijärjestelmän mitattuihin vasteisiin.