Made available in DSpace on 2014-06-11T19:22:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-11-17Bitstream added on 2014-06-13T18:08:28Z : No. of bitstreams: 1 silva_lce_me_ilha.pdf: 4149122 bytes, checksum: ab06272dc64be8ae36635022c8412d4c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Considerando-se as constantes mudanças que vêm ocorrendo no cenário de distribuição de energia elétrica, devido ao grande avanço da eletrônica de potência e cargas não lineares instaladas no sistema elétrico, fazem-se necessários estudos para diagnosticar como e quanto essas alterações interferem nos equipamentos instalados nas redes de distribuição. A proposta desta dissertação é a análise da influência das distorções harmônicas (tensões e correntes) e desequilíbrios (tensões) nos erros de medição de energia elétrica ativa em medidores eletrônicos trifásicos. Estes equipamentos são normalmente projetados para atuarem com condições ideais de freqüência constante, formas de onda de tensão e corrente senoidais e em sistemas equilibrados. Condições estas, que não refletem a realidade das redes de distribuição de energia elétrica. Para a realização da análise dos equipamentos selecionados, submetidos aos efeitos das componentes harmônicas nas tensões e correntes, inclusive desequilíbrios de tensões, montou-se um arranjo padrão de medição, onde foram ensaiados os medidores submetidos a estes distúrbios, sob as mesmas condições laboratoriais, considerando-se três repetições para cada amostra selecionada. As distorções harmônicas de tensões e correntes, aplicadas nos ensaios, foram obtidas por medições em consumidores em ramais de distribuição com características industrial, comercial, rural e residencial, e, os desequilíbrios de tensões admitidos para ensaios foram de 3% (limite atual) e de 5%, considerando-se determinados cenários de um sistema de distribuição real de uma concessionária de energia elétrica. Os resultados são apresentados em forma de tabelas e figuras, e, as análises dos erros são apresentadas considerando-se um padrão de medição composto por analisador de energia com classe de exatidão... / Considering the constant changes that have been occurring in the electric energy distribution scenery, due to the great improvements of the power electronics devices and non linear loads installed in the system, there are several studies developed in order to analyze and diagnosis the effects of these changes, and how much these loads affect the equipments installed on the distribution systems. The proposal of this research is to analyze the influence the harmonic contents (voltage and current) and unbalances (voltage) in the systems on the measurement errors of the active electric energy using three-phase electronic meters. These equipments are usually designed to operate on ideal conditions with constant frequency, sinusoidal voltage and current waveforms, and balanced system. However, these conditions are not the reality of the electric energy distribution systems. The procedures for the measurements, considering the selected samples of the electronics meters under influence of current and voltage harmonic contents, and voltage unbalances, were based on a measurement set-up established for testing, in the same conditions, all the selected samples considering its three repetitions. The harmonic voltage and current contents, applied in the tests, were obtained by measurements in consumers with different load characteristics (industrial, commercial, rural and residential), and the admitted voltage unbalances were of 3% (actual limit imposed by standards) and 5%, considering real cases of an electric energy distribution system of an utilities. The results are summarized in tables and figures, and the analyses of the errors are presented considering comparisons with a standard of measurement composed by an energy analyzer, with accuracy of 0.1% for voltages and currents, and, 0.2% for active power, considering the range of 60Hz until 1kHz. In addition, models were developed... (Complete abstract click electronic access below)

Orientador : Moacyr Trindade de Oliveira Andrade / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-03T13:46:36Z (GMT). No. of bitstreams: 1 Ito_HelioTakashi_M.pdf: 5252784 bytes, checksum: ae8d7712120ea00521b3a11548526975 (MD5) Previous issue date: 2003 / Mestrado

Orientador: Elnatan Chagas Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T07:37:40Z (GMT). No. of bitstreams: 1 Bacurau_RodrigoMoreira_M.pdf: 7520389 bytes, checksum: 2e88cad485dbbbdbd306a531c0ed2298 (MD5) Previous issue date: 2014 / Resumo: Neste trabalho é apresentado o desenvolvimento de um módulo medidor de energia residencial capaz de medir, além do consumo de energia total, os parâmetros elétricos necessários para a discriminação de consumo de energia por aparelho. Também é apresentado um levantamento de quais parâmetros elétricos derivados das curvas de tensão e corrente são úteis para a definição de assinatura de cargas residenciais. Os resultados dos experimentos realizados indicaram a potência ativa, a potência reativa, o fator de potência, a tensão e corrente eficazes e as cinco primeiras harmônicas ímpares do sinal de corrente como os parâmetros mais adequados para uso em sistemas não intrusivos para identificação de consumo por aparelho. Graças a técnicas de programação e decisões de projeto acertadas, foi possível desenvolver um módulo medidor de alta precisão e baixo custo, usando um microcontrolador simples e de baixo consumo. Este módulo é capaz de calcular todas as grandezas elétricas supramencionadas a frequência de 46 Hz. Os valores de tensão, corrente, fator de potência, potência ativa e potência aparente apresentaram erros inferiores a 0,3% (para cargas resistivas). O erro nas componentes harmônicas do sinal de corrente foi de 0,03% para a componente fundamental, 0,58% para a 3ª harmônica, 3,69% para a 5ª harmônica, 6,63% para a 7ª harmônica e 11,81% para a 9ª harmônica. O medidor desenvolvido será usado no projeto "Sistema Inteligente de Gestão Energética para Unidades Consumidoras de Baixa Tensão" o qual consistirá em um sistema completo de gestão de consumo de energia residencial / Abstract: We present in this project the development of a residential power meter module capable of measuring besides the total energy consumption, the electrical parameters needed for power consumption breakdown. We also present a study of which electrical features derived from current and voltage waveforms are more adequate to define signatures of residential loads. The experimental results indicated that the active power, reactive power, power factor, voltage, current and the first five odd harmonics of the current signal are good parameters to use in Non-Intrusive Load Monitoring Systems - NILM. Thanks to the use of advanced programming techniques and right design decisions, we developed, using a simple microcontroller, a high-precision, low-power and low cost smart meter. This module is capable to calculate all electrical parameters above mentioned at 46 Hz frequency. The voltage, current, power factor active and apparent power presented errors lower than 0.3% for resistive loads. The error in the harmonics of the current signal was 0.03% for the fundamental harmonic, 0.58% for the 3rd harmonic, 3.69% for the 5th harmonic, 6.63% for the 7th harmonic and 11.81% for the 9th harmonic. The smart meter presented here will be used in a larger project entitled "Intelligent Energy Management System for Consumer Units Low Voltage" which consists of a complete management system of residential energy consumption / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

The events of September 11, 2001, seemed to many to presage the end of the skyscraper as an urban form. Some 15 years later, the skyscraper is more prevalent than ever before, owing to its unique advantages over other building forms in an urban, environmental, and sociological context. Skyscrapers are rising ever higher, pushing the limits of architecture and engineering. In 2001 there were 23 buildings over 1,000 feet in height. As of this writing there are 173 buildings over 1,000 feet completed or under construction, with 300 more in various phases of proposal. Despite their enormous initial cost in both capital and energy, the skyscraper maximizes the use of constricted urban space and provides enormous opportunities for technological and sociological innovation which, despite more that 100 years of skyscraper construction, are only just beginning to be realized. This thesis will explore a number of as-yet unrealized possibilities for skyscraper development to prognosticate and articulate future typologies designed to address increasing problems of energy efficiency, population density and disaster preparedness. As the human population grows, and more people move to the cities, larger and larger buildings will be necessary to house them at densities sufficient to ensure energy efficiency and minimize sprawl. The skyscraper is uniquely suited to meet these demands. / Master of Architecture

Made available in DSpace on 2016-12-12T20:15:54Z (GMT). No. of bitstreams: 1 pre_textuais.pdf: 54354 bytes, checksum: 81cdd6a9b6a26b1b93efdeee869b2de9 (MD5) Previous issue date: 2011-07-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work we study the self-organization of periodic structures on parameter-spaces of the largest Lyapunov exponent (Lyapunov diagrams) of the Watt governor system model. A hierarchical organization and period-adding bifurcation cascades of the periodic structures are observed, and these self-organized cascades accumulate on a periodic boundary. We also show that the periods of the structures organize themselves obeying the solutions of a diophantine equation. / Neste trabalho estudamos a auto-organização de estruturas periódicas no espaço de parâmetros do maior expoente de Lyapunov (diagramas de Lyapunov) em um modelo do sistema regulador deWatt. Uma organização hierárquica e cascatas de bifurcação por adição de período das estruturas periódicas são observadas e estas cascatas auto-organizadas se acumulam em fronteiras periódicas. Também mostramos que os períodos das estruturas organizam-se obedecendo as soluções de equações diofantina

Bakgrund: Tidigare forskning har visat att den aeroba kapaciteten i delar av den svenska befolkningen har försämrats under en längre tid. Syfte: Syftet med uppsatsen är att undersöka ifall de mönstrande ungdomarna för åren 2001, 2008 och 2018 följer samma nedåtgående trend när det gäller aerob kapacitet som tidigare forskning har visat för andra delar av befolkningen. Samt undersöka om en liknande nedåtgående trend går att hitta för muskelstyrka. Metod: Data som samlades in var från Rekryteringsmyndighetens mönstringstester för åren 2001(män N=18 074, kvinnor N=487), 2008(män N=15709, kvinnor N=911) och 2018(män N=4453, kvinnor N=1346). Dessa data jämfördes emot varandra med ett t-test. Data som analyserades var muskelstyrka, aerob kapacitet och vikt. Resultat: Resultatet för kvinnor och män när det gäller aerob kapacitet minskade med 7 % för kvinnor respektive 8 % för män från året 2001. Resultatet gällande muskelstyrka ökade med 8 % för kvinnor och 11 % för män från året 2001. Slutsats: Den minskade aeroba kapacitet ligger i linje med den tidigare forskningen som visar en försämring hos både kvinnor och män. Trenden när det gäller muskelstyrka visar en förbättring hos både kvinnor och män. Detta öppnar frågan för vad dessa trender beror på?

Le kilogramme est la seule unité de base du système international encore définie par un artefact matériel. Le Laboratoire National de métrologie et d'Essais (LNE) développe, dans le cadre d'un projet fédéré, une expérience nommée balance du watt dont le but est de contribuer à la redéfinition de l'unité de masse.<br />Les travaux réalisés au cours de cette thèse ont pour but de contrôler, sur une plage de l'ordre de quelques centimètres, la vitesse de déplacement et le positionnement d'une bobine à l'aide d'un dispositif constitué d'un interféromètre hétérodyne associé à une platine de translation et à un actionneur piézo-électrique. Une source laser a été développée afin de mieux adapter la méthode aux contraintes exigées par la balance du watt. La méthode de contrôle de vitesse permet une instabilité résiduelle relative de 2.4⊂10-9 pour un simple miroir pesant quelques grammes et de 4,2⊂10-7 pour une masse de 1200 g, ceci sur 100 secondes de temps d'intégration. La méthode développée a par ailleurs démontrée son utilité dans d'autres applications en nanométrologie.

A method for improving performance/watt of an embedded single-instruction multiple-data (SIMD) architecture using application-guided a priori scheduling of hardware resources is presented. A multi-core architectural simulator is adopted that accurately estimates power, performance, and utilization of various processor components (logic, interconnect and memory). A greedy search is then performed on each algorithm block of a signal processing chain in order to schedule each component's throughput and power. The proposed software-directed hardware rebalancing, applied to a typical electroencephalography (EEG) filtering chain, is analyzed for two different SIMD architectures. The first, representing a super V[subscript th] processor demonstrates a 51%-86% improvement in performance/watt at 1%-10% throughput reduction using block level or algorithm level a priori scheduling. The second architecture used is Synctium, a near V[subscript th] processor which demonstrates 50%-99% performance/watt improvement across the same throughput reduction range and optimization techniques. / Graduation date: 2012

Univ., Diss.--Oldenburg, 1998. / Auch als: Berichte // Forschungszentrum Terramare ; 9.

This study explores the history of a group of London handicraftsmen, the multi-skilled millwrights, who were power-transmission mechanics and rudimentary engineers, from 1775-1825. It reveals an organised group of old-style journeymen, who had developed a powerful grip on all aspects of the trade itself, not just their terms and conditions (which were in the top bracket of London artisans of the time). This amounted to a power-sharing partnership with their masters who accepted this arrangement for decades of the late eighteenth century because of the millwrights' unique skills, quality work and organised power as a trade club. The millwrights as individual handicraftsmen varied from 'rough and ready rule of thumb' mechanics to ingenious mechanical and civil engineers. Many of these latter could design and erect complex buildings and infrastructure for water, wind or horse-driven mills and install the transmission millwork/gear wheels of the time. They were, in effect, a powerful guild to which many of the masters belonged. With the growing demand for larger and more complex power sources of the early industrial revolution, this traditional trade came under tremendous pressure to overcome the restrictions imposed by the journeymen millwrights, especially from the businesses who employed the masters as contractors. The study examines the previously unappreciated role of the London brewers, distillers and other manufacturers in pressurising the master millwrights to resist the power of their combined journeymen. It was this pressure which induced the master millwrights to bring to Parliament a Combination Bill seeking to outlaw the London Society of Journeymen Millwrights' trade club and replace them by wage regulation of the magistrates of the City and neighbouring Home Counties. This wider development is examined in detail. Those City employers were also prominent in the more successful 1812-14 bid to remove the medieval apprenticeship laws which then underpinned all journeymen's control of skilled labour supply. But it was the exigencies of the wars with the French from the 1800s which really drove the technological changes which undermined the millwrights' exclusive control of mechanical work, especially using the new, better quality fabrication of iron and machinery. This development is examined at the Portsmouth naval dockyard in 1805 and the spread of new engineering works in the London area thereafter. A new breed of engineering employer now emerged who were successful in breaking the millwrights' grip on the trade with greater control in larger establishments. They made a practice of employing/training non- or short-apprenticed skilled fitters, turners and a variety of other specialised engineering workers to do aspects of the more expensive and less tractable high-skilled millwrights with what became known as an Engineers' Economy. This little-known episode of early British engineering history was illustrated throughout with contemporary prints and drawings and pen-pictures of the key figures who became involved - John Rennie, James Watt and Henry Maudslay, to name but a few. An update and rewrite has recently been produced entitled, The Old London Artisans: the Millwrights 1775-1825.