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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.
1

Proposta de equipamento para medição dos fenômenos relativos à qualidade da energia elétrica utilizando conceitos de instrumentos virtuais / Power quality measuring equipment proposal based on virtual instruments conception

Matana, Gleison Melhado 15 April 2008 (has links)
Este trabalho apresenta um estudo da literatura pertinente sobre qualidade da energia elétrica. O estudo apresentado está baseado na evolução do tema em nível nacional e internacional, buscando explicar o conceito dos principais fenômenos e selecionar as recentes resoluções e normas que regem os princípios de medição e os limites dos distúrbios eletromagnéticos que os caracterizam. As normas da IEC foram selecionadas para a aplicação na construção de um protótipo de um medidor de qualidade da energia elétrica, onde o princípio construtivo é o de instrumento virtual por sua flexibilidade de arquitetura. A implementação do protótipo dá-se em um microcomputador padrão de mercado pelo software LabVIEW, através de vários módulos independentes para cada distúrbio a ser medido. Os resultados numéricos das simulações executadas frente a cada distúrbio, gerando comparações entre valores aplicados e valores medidos são apresentados em forma de tabelas com seus respectivos erros percentuais para cada grandeza de cada módulo. / This dissertation presents a study of existing literature about power quality. The study presented is based on a theme evolution in national and international environment, trying to explain the main phenomenon conceptions and select the most recent standards that rule the measurement conceptions and the electromagnetic disturbances limits that characterize it. The IEC standard were selected to build a prototype of a power quality measure device where the construction conception is a virtual instrument because it has a flexible architecture. The prototype implementation was made from a common computer by the LabVIEW software through some independent modules for each disturbance to be measured. The numerical results of executed simulations of each disturbance generating comparisons between applied values and measured values are presented as tables within their percentage error for each phenomenon of each module.
2

Maintenance of the Quality Monitor Web-Application

Ponomarenko, Maksym January 2013 (has links)
Applied Research in System Analysis (ARiSA) is a company specialized in the development of the customer-specific quality models and applied research work. In order to improve the quality of the projects and to reduce maintenance costs, ARiSA developed Quality Monitor (QM) – a web application for quality analysis. QM application has been originally developed as a basic program to enable customers to evaluate the quality of the sources. Therefore, the business logic of the application was simplified and certain limitations were imposed on it, which in its turn leads to a number of issues related to user experience, performance and architecture design. These aspects are important for both application as a product, and for its future promotion. Moreover, this is important for customers, as end users. Main application issues, which were added to the maintenance list are: manual data upload, insufficient server resources to handle long-running and resource consuming operations, no background processing and status reporting, simplistic presentation of analysis results and known usability issues, weak integration between analysis back-ends and front-end. ­­­­­­­­­­­In order to address known issues and to make improvements of the existing limitations, a maintenance phase of QM application is initiated. First of all, it is intended to stabilize current version and improve user experience. It also needed for refactoring and implementation of more efficient data uploads processing in the background. In addition, extended functionality of QM would fulfill customer needs and transform application from the project into a product. Extended functionality includes: automated data upload from different build processes, new data visualizations, and improvement of the current functionality according to customer comments. Maintenance phase of QM application has been successfully completed and master thesis goals are met. Current version is more stable and more responsive from user experience perspective. Data processing is more efficient, and now it is implemented as background analysis with automatic data import. User interface has been updated with visualizations for client-side interaction and progress reporting. The solution has been evaluated and tested in close cooperation with QM application customers. This thesis describes requirements analysis, technology stack with choice rationale and implementation to show maintenance results.
3

Quality assessment of a large real world industry project

Glazunov, Vladimir January 2013 (has links)
Quality Monitor is application, which automatically analyzes software projects forquality and makes quality assessment reports. This thesis project aims to instantiate Quality Monitor for a large real-world .Net project and to extend Quality Monitor by considering other data sources than just source code. This extended analysis scope includes bug reports, features, and time reports besides .Net assemblies (code) as artifacts. Different tools were investigated for the analysis of code, bug reports, features and time reports. The analysis of .Net assemblies was implemented as none of the existing tools under evaluation met all requirements. The analysis of .Net assemblies was successfully completed; it allows the extraction data necessary for creating Call and Control Flow graphs. These graphs are used for calculating additional metrics allowing for an improved assessment of quality of the project. Implementation of .Net assembly reader was tested using large real world industrial project. Other data sources were analyzed theoretically, but excluded for further implementation. Altogether the thesis includes an analysis of possible Quality Monitor extensions including their requirements, design, and (partially) their implementation and evaluation.
4

Proposta de equipamento para medição dos fenômenos relativos à qualidade da energia elétrica utilizando conceitos de instrumentos virtuais / Power quality measuring equipment proposal based on virtual instruments conception

Gleison Melhado Matana 15 April 2008 (has links)
Este trabalho apresenta um estudo da literatura pertinente sobre qualidade da energia elétrica. O estudo apresentado está baseado na evolução do tema em nível nacional e internacional, buscando explicar o conceito dos principais fenômenos e selecionar as recentes resoluções e normas que regem os princípios de medição e os limites dos distúrbios eletromagnéticos que os caracterizam. As normas da IEC foram selecionadas para a aplicação na construção de um protótipo de um medidor de qualidade da energia elétrica, onde o princípio construtivo é o de instrumento virtual por sua flexibilidade de arquitetura. A implementação do protótipo dá-se em um microcomputador padrão de mercado pelo software LabVIEW, através de vários módulos independentes para cada distúrbio a ser medido. Os resultados numéricos das simulações executadas frente a cada distúrbio, gerando comparações entre valores aplicados e valores medidos são apresentados em forma de tabelas com seus respectivos erros percentuais para cada grandeza de cada módulo. / This dissertation presents a study of existing literature about power quality. The study presented is based on a theme evolution in national and international environment, trying to explain the main phenomenon conceptions and select the most recent standards that rule the measurement conceptions and the electromagnetic disturbances limits that characterize it. The IEC standard were selected to build a prototype of a power quality measure device where the construction conception is a virtual instrument because it has a flexible architecture. The prototype implementation was made from a common computer by the LabVIEW software through some independent modules for each disturbance to be measured. The numerical results of executed simulations of each disturbance generating comparisons between applied values and measured values are presented as tables within their percentage error for each phenomenon of each module.
5

Electromagnetic Compatibility Of Electric Power Quality Monitor According To En 61326 Standard

Yaman, Ozgur 01 December 2007 (has links) (PDF)
In this thesis / Electromagnetic Compatibility (EMC) of Electric Power Quality Monitor developed within the scope of National Power Quality Project has been investigated according to EN 61326 standard. Both immunity and emission tests have been carried out in EMC laboratories of ELDAS and ASELSAN for the device under test. Necessary counter measures such as using electromagnetic interference (EMI) filters and transient voltage suppressors, shielding the case of device with EMI protective materials have been taken to satisfy the immunity and emission limits defined in the standard for the device, and their success have been verified by laboratory tests. This research work has been fully supported by Public Research Grant Committee (KAMAG) of T&Uuml / B&amp / #272 / TAK within the scope of National Power Quality Project (105G129).
6

Metodologia e simplificação do espaço de busca para a alocação de medidores de qualidade da energia elétrica frente às variações de tensão de curta duração / Methodology and simplification of the search space for power quality monitor allocation facing voltage variations

Gomes, Douglas Pinto Sampaio 28 June 2016 (has links)
A presente pesquisa tem como tema principal a alocação otimizada de Monitores de Qualidade da Energia Elétrica (MQEEs) em sistemas de distribuição para a observação das Variações de Tensão de Curta Duração (VTCDs). Busca-se pela pesquisa apresentar adequações que podem ser facilmente incorporadas aos métodos de alocação que se baseiam no uso de algoritmos inteligentes, neste caso em específico, em Algoritmos Genéticos (AGs), para resolver o problema da alocação de MQEEs. Também como contribuição, a pesquisa apresenta uma técnica para a diminuição do espaço de busca das soluções, imprimindo assim, uma melhoria da observação das VTCDs em Sistemas de Distribuição (SDs), e caracterizando um método simplificado para a alocação desejada. A metodologia como formulada (via AG e método simplificado) foi testada através da sua aplicação nos sistemas de distribuição de 13, 34 e 123 nós, simulados via o ATP (Alternative Transients Program), e provindos da base de dados do IEEE (Institute of Electrical and Electronic Engineers). A pesquisa também foi testada considerando um alimentador real de uma concessionária regional, e validada através de simulações estatísticas pelo Método de Monte Carlo. / The present research has the optimized allocation of Power Quality Monitors in distribution systems as its main subject aimed at voltage sags and swells observation. The work intention is to propose adjustments that can be easily incorporated into the allocation methods based on the use of intelligent algorithms, in this case specifically, the Genetic Algorithms addressing the problem of monitor allocation. Also, as contribution, the research presents a technique to reduce the search space of solutions, thus printing an improvement on the observation of voltage variations in distribution systems and characterizing a simplified method for the desired allocation. The methodology, as formulated (by the genetic algorithm application and the simplified method), was tested through its application in distribution systems of 13, 34 and 123 nodes, simulated on ATP (Alternative Transients Program), and stemmed by the IEEE database (Institute of Electrical and Electronic Engineers). The research was also tested considering a real feeder of a regional utility, and validated through statistical simulations by the Monte Carlo method.
7

Metodologia e simplificação do espaço de busca para a alocação de medidores de qualidade da energia elétrica frente às variações de tensão de curta duração / Methodology and simplification of the search space for power quality monitor allocation facing voltage variations

Douglas Pinto Sampaio Gomes 28 June 2016 (has links)
A presente pesquisa tem como tema principal a alocação otimizada de Monitores de Qualidade da Energia Elétrica (MQEEs) em sistemas de distribuição para a observação das Variações de Tensão de Curta Duração (VTCDs). Busca-se pela pesquisa apresentar adequações que podem ser facilmente incorporadas aos métodos de alocação que se baseiam no uso de algoritmos inteligentes, neste caso em específico, em Algoritmos Genéticos (AGs), para resolver o problema da alocação de MQEEs. Também como contribuição, a pesquisa apresenta uma técnica para a diminuição do espaço de busca das soluções, imprimindo assim, uma melhoria da observação das VTCDs em Sistemas de Distribuição (SDs), e caracterizando um método simplificado para a alocação desejada. A metodologia como formulada (via AG e método simplificado) foi testada através da sua aplicação nos sistemas de distribuição de 13, 34 e 123 nós, simulados via o ATP (Alternative Transients Program), e provindos da base de dados do IEEE (Institute of Electrical and Electronic Engineers). A pesquisa também foi testada considerando um alimentador real de uma concessionária regional, e validada através de simulações estatísticas pelo Método de Monte Carlo. / The present research has the optimized allocation of Power Quality Monitors in distribution systems as its main subject aimed at voltage sags and swells observation. The work intention is to propose adjustments that can be easily incorporated into the allocation methods based on the use of intelligent algorithms, in this case specifically, the Genetic Algorithms addressing the problem of monitor allocation. Also, as contribution, the research presents a technique to reduce the search space of solutions, thus printing an improvement on the observation of voltage variations in distribution systems and characterizing a simplified method for the desired allocation. The methodology, as formulated (by the genetic algorithm application and the simplified method), was tested through its application in distribution systems of 13, 34 and 123 nodes, simulated on ATP (Alternative Transients Program), and stemmed by the IEEE database (Institute of Electrical and Electronic Engineers). The research was also tested considering a real feeder of a regional utility, and validated through statistical simulations by the Monte Carlo method.
8

Analýza kvality obrazu v digitálních televizních systémech / Picture Quality Analysis in Digital Television Systems

Bednarz, Robin January 2009 (has links)
Diploma thesis deals with the analysis of quality in digital television systems and contains theoretical description of subjective and objective assessment of quality picture methods. The thesis contains short-term and long-term analysis of quality picture of terrestrial television DVB-T. Measurements and experimentations were carried out with the help of Rohde&Schwarz DVQ analyzer of picture quality and software MPEG-2 Quality Monitor and MPEG-2 Elementary stream analyzer.

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