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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.
21

PSINCO-um programa para calculo da distribuicao de potencia e supervisao do nucleo de reatores nucleares, utilizando sinais de detetores tipo 'SPD'

HIROMOTO, MARIA Y.K. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:43:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:31Z (GMT). No. of bitstreams: 1 06442.pdf: 6689802 bytes, checksum: 46ba1e2b896e77a4288d24e80ac804ff (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
22

Utilizacao de redes neurais na monitoracao da potencia do reator IEA-R1

ROSSI, ROSA H.P.S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:45:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:32Z (GMT). No. of bitstreams: 1 07285.pdf: 7589238 bytes, checksum: 2dd074efcd927657975875bc5a121997 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
23

Desenvolvimento de um amplificador isolador para analise de sinais dinamicos

DYRJAWOJ, NICOLAU 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:25Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:36Z (GMT). No. of bitstreams: 1 08984.pdf: 7815530 bytes, checksum: 2846bcddfb4f882d621deacbf8447f3e (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
24

Análise das variáveis de entrada de uma rede neural usando teste de correlação e análise de correlaçao canônica / Analysis of input variables of an artificial neural network using bivariate correlation and canonical correlation

COSTA, VALTER M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:03Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:52Z (GMT). No. of bitstreams: 0 / A monitoração de variáveis e o diagnóstico de falhas é um aspecto importante a se considerar seja em plantas nucleares ou indústrias de processos, pois um diagnóstico precoce de falha permite a correção do problema proporcionando a não interrupção da produção e a segurança do operador e, assim, não causando perdas econômicas. O objetivo deste trabalho é, dentro do universo de todas as variáveis monitoradas de um processo, construir um conjunto de variáveis, não necessariamente mínimo, que será a entrada de uma rede neural e, com isso, conseguir monitorar, o maior número possível de variáveis. Esta metodologia foi aplicada ao reator de pesquisas IEA-R1 do IPEN. Para isso, as variáveis Potência do reator, Vazão do primário, Posição de barras de controle/segurança e Diferença de pressão no núcleo do reator D P, foram agrupadas, pois por hipótese quase todas as variáveis monitoradas em um reator nuclear tem relação com alguma dessas ou pode ser resultado da interação de duas ou mais. Por exemplo, a Potência está relacionada ao aumento e diminuição de algumas temperaturas bem como à quantidade de radiação devido à fissão do urânio; as Barras são reguladoras de potência e, por conseqüência podem influenciar na quantidade de radiação e/ou temperaturas; a Vazão do Circuito Primário, responsável pelo transporte de energia e pela conseqüente retirada de calor do núcleo. Assim, tomando o grupo de variáveis mencionadas, calculamos a correlação existente entre este conjunto B e todas as outras variáveis monitoradas (coeficiente de correlação múltipla), isto é, através do cálculo da correlação múltipla, que é uma ferramenta proposta pela teoria das Correlações Canônicas, foi possível calcular o quanto o conjunto B pode predizer cada uma das variáveis monitoradas. Uma vez que não seja possível uma boa qualidade de predição com o conjunto B, é acrescentada uma ou mais variáveis que possuam alta correlação com a variável melhorando a qualidade de predição. Finalmente, uma rede pode ser treinada com o novo conjunto e os resultados quanto a monitoração foram bastante satisfatórios quanto às 64 variáveis monitoradas pelo sistema de aquisição de dados do reator IEA-R1 através de sensores e atuadores , pois com um conjunto de 9 variáveis foi possível monitorar 51 variáveis. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
25

Metodologia para monitoracao e diagnostico de vibracao das bombas moto-operadas do circuito primario de refrigeracao do Reator IEA-R1

BENEVENUTI, ERION de L. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:23Z (GMT). No. of bitstreams: 1 09626.pdf: 11035558 bytes, checksum: 15aa6dd9cdacdf9c6ea1b493f68aba84 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
26

Visualizing industrial energy use : Inviting shop floor employees to the conversation

Kullberg, Michael January 2022 (has links)
Researchers and industrial actors alike have identified employees as a potential resource ineffective energy management. Access to visualized progress of energy efficiency is said tobe required for this to be successful, yet few have identified if there are differences in therequirements based on the industrial roles. This survey-based study has aimed to begin thisconversation by comparing shop floor employees and managers in terms of perceivedimportance of energy efficiency and underlying motivation to behave energy efficiently.Additionally, a small randomized set of visualizations containing energy related informationwas presented in order to identify if some information had a higher impact on perceivedenergy use, associated costs, environmental impact and prioritization of energy efficiency.Although no statistically significant differences related to the type of information displayedwere found, the results indicate that both managers and shop floor employees place highimportance on energy efficiency in the workplace and have similar motivations to act energyefficiently. On average, both shop floor employees and managers believe a 26% increase inenergy efficiency is possible to achieve in their industry.
27

A video-based traffic monitoring system

Magaia, Lourenco Lazaro 12 1900 (has links)
Thesis (PhD (Mathematical Sciences. Applied Mathematics))--University of Stellenbosch, 2006. / This thesis addresses the problem of bulding a video-based traffic monitoring system. We employ clustering, trackiing and three-dimensional reconstruction of moving objects over a long image sequence. We present an algorithms that robustly recovers the motion and reconstructs three-dimensional shapes from a sequence of video images, Magaia et al [91]. The problem ...
28

Sistemas optoeletrônicos portáteis para detecção de gases, oxigênio dissolvido e de metais pesados aplicados no controle ambiental. / Portable environmental monitoring systems, dissolved oxygen, heavy metals, colorimetric, fluorimetry.

Braga, Mauro Sergio 02 August 2016 (has links)
O monitoramento ambiental de forma contínua e em tempo real são desafios da realidade atual dos grandes centros urbanos, com a finalidade de prevenir desastres ambientais que possam pôr em perigo a saúde dos seres humanos e a existência de sistemas biológicos. Na presente tese foram propostos e desenvolvidos sistemas optoeletrônicos portáteis aplicados na detecção de O2, OD e íons de metais pesados, visando seu emprego no monitoramento de sistemas hidrológicos como mares, rios, lagos e lençóis freáticos. A definição final da estrutura do sistema portátil foi atingida após o desenvolvimento sistemático de diferentes ensaios experimentais. Primeiramente, foram estudadas e analisadas matrizes hospedeiras em estado sólido que fossem capazes de hospedar sistemas moleculares corantes sensíveis a certas substâncias específicas. A seguir, foi proposta e executada a integração direta dos filmes hospedeiros, dopados com moléculas corantes ativas, diretamente na superfície ativa de dispositivos fotodetectores para detecção de O2 e OD. Os resultados obtidos com estes sistemas que integram o detector e o filme ativo mostraram o mesmo nível de desempenho aos espectrômetros de bancada. Finalmente, de posse destes resultados, foi projetado e desenvolvido um sistema colorimétrico e fluorimétrico portátil e embarcado em uma placa de aquisição (myRIO-1900) da National Instruments, aplicado na detecção e classificação de íons metálicos. Destaque principal é outorgado à aplicação do colorímetro que, juntamente com o processamento de sinais e análises de padrões, utilizando o método de discriminante de Fisher, permitiu obter resultados excelentes na detecção e classificação dos íons de Pb2+, Cd2+, Zn2+, Cu2+, Fe3+ e Ni2+, com os mesmos níveis de desempenho que os obtidos a partir de espectrômetros de bancada de elevada resolução espectral. O sistema portátil desenvolvido sugere sua aplicação no controle ambiental in situ e em tempo real, podendo ser integrado em uma rede de sensores que possam fornecer dados de maneira contínua e receber comandos de centros de controle de monitoramento ambiental. No entanto, seria necessária a formulação de algoritmos eficientes no processo de mineração de dados da rede de sensores. / The continuous and in real time environmental monitoring are challenges of the current days of large urban centers, with the aim of preventing environmental disasters that could endanger human health and the existence of biological systems. In this thesis we have proposed and developed portable optoelectronic systems applied to the detection of O2, OD and heavy metal ions, aiming its use in monitoring hydrological systems such as oceans, rivers, lakes and groundwater. The final definition of the portable system structure was achieved after the systematic development of different experimental assays. First, host matrices were studied and analyzed in solid state which were able to host dye molecular systems sensitive to certain substances. Then, we proposed and executed the direct integration of the host film, doped with active dye molecules directly on the active surface of photodetector devices to the detection of O2 and OD. The results obtained with these systems that integrate the detector and the active film showed the same level of performance than those of benchtop spectrometers. Finally, with these results, we designed and developed a colorimetric and fluorimetric portable system with an embedded acquisition board (myRIO-1900) from National Instruments, applied to the detection and classification of metal ions. Main focus is given to the application of the colorimeter which, along with the signal processing and pattern analysis using the Fisher discriminant method, allowed to obtain excellent results in the detection and classification of Pb2+, Cd2+, Zn2+, Cu2+, Fe3+ and Ni2+ ions, with the same level of performance related to those obtained from high spectral resolution benchtop spectrometers. The portable system developed in the present thesis suggests its application in environmental control in situ and in real time, so that it can be integrated in a network of sensors that may provide continuous data and receive commands from environmental monitoring control center; nevertheless, requiring for that the development of efficient algorithms in data mining process of the sensor network.
29

Sistemas optoeletrônicos portáteis para detecção de gases, oxigênio dissolvido e de metais pesados aplicados no controle ambiental. / Portable environmental monitoring systems, dissolved oxygen, heavy metals, colorimetric, fluorimetry.

Mauro Sergio Braga 02 August 2016 (has links)
O monitoramento ambiental de forma contínua e em tempo real são desafios da realidade atual dos grandes centros urbanos, com a finalidade de prevenir desastres ambientais que possam pôr em perigo a saúde dos seres humanos e a existência de sistemas biológicos. Na presente tese foram propostos e desenvolvidos sistemas optoeletrônicos portáteis aplicados na detecção de O2, OD e íons de metais pesados, visando seu emprego no monitoramento de sistemas hidrológicos como mares, rios, lagos e lençóis freáticos. A definição final da estrutura do sistema portátil foi atingida após o desenvolvimento sistemático de diferentes ensaios experimentais. Primeiramente, foram estudadas e analisadas matrizes hospedeiras em estado sólido que fossem capazes de hospedar sistemas moleculares corantes sensíveis a certas substâncias específicas. A seguir, foi proposta e executada a integração direta dos filmes hospedeiros, dopados com moléculas corantes ativas, diretamente na superfície ativa de dispositivos fotodetectores para detecção de O2 e OD. Os resultados obtidos com estes sistemas que integram o detector e o filme ativo mostraram o mesmo nível de desempenho aos espectrômetros de bancada. Finalmente, de posse destes resultados, foi projetado e desenvolvido um sistema colorimétrico e fluorimétrico portátil e embarcado em uma placa de aquisição (myRIO-1900) da National Instruments, aplicado na detecção e classificação de íons metálicos. Destaque principal é outorgado à aplicação do colorímetro que, juntamente com o processamento de sinais e análises de padrões, utilizando o método de discriminante de Fisher, permitiu obter resultados excelentes na detecção e classificação dos íons de Pb2+, Cd2+, Zn2+, Cu2+, Fe3+ e Ni2+, com os mesmos níveis de desempenho que os obtidos a partir de espectrômetros de bancada de elevada resolução espectral. O sistema portátil desenvolvido sugere sua aplicação no controle ambiental in situ e em tempo real, podendo ser integrado em uma rede de sensores que possam fornecer dados de maneira contínua e receber comandos de centros de controle de monitoramento ambiental. No entanto, seria necessária a formulação de algoritmos eficientes no processo de mineração de dados da rede de sensores. / The continuous and in real time environmental monitoring are challenges of the current days of large urban centers, with the aim of preventing environmental disasters that could endanger human health and the existence of biological systems. In this thesis we have proposed and developed portable optoelectronic systems applied to the detection of O2, OD and heavy metal ions, aiming its use in monitoring hydrological systems such as oceans, rivers, lakes and groundwater. The final definition of the portable system structure was achieved after the systematic development of different experimental assays. First, host matrices were studied and analyzed in solid state which were able to host dye molecular systems sensitive to certain substances. Then, we proposed and executed the direct integration of the host film, doped with active dye molecules directly on the active surface of photodetector devices to the detection of O2 and OD. The results obtained with these systems that integrate the detector and the active film showed the same level of performance than those of benchtop spectrometers. Finally, with these results, we designed and developed a colorimetric and fluorimetric portable system with an embedded acquisition board (myRIO-1900) from National Instruments, applied to the detection and classification of metal ions. Main focus is given to the application of the colorimeter which, along with the signal processing and pattern analysis using the Fisher discriminant method, allowed to obtain excellent results in the detection and classification of Pb2+, Cd2+, Zn2+, Cu2+, Fe3+ and Ni2+ ions, with the same level of performance related to those obtained from high spectral resolution benchtop spectrometers. The portable system developed in the present thesis suggests its application in environmental control in situ and in real time, so that it can be integrated in a network of sensors that may provide continuous data and receive commands from environmental monitoring control center; nevertheless, requiring for that the development of efficient algorithms in data mining process of the sensor network.
30

Spatial Dynamics and Productivity of a Gulf of Mexico Commercial Reef Fish Fishery Following Large Scale Disturbance and Management Change

Cockrell, Marcy Lynn 18 April 2018 (has links)
The Gulf of Mexico commercial reef fish fishery has experienced significant management changes and disturbance in recent years, including transitioning two major fisheries from a traditional open access system into a limited entry individual fishing quota (IFQ) system in 2007 and 2010. Also in 2010, the Deepwater Horizon oil spill (DWH) released an estimated 4.9 million barrels of oil into the Gulf (~206 million U.S. gallons), and is still the largest U.S. environmental disaster to date. Emergency fishing closures initiated shortly after the oil spill began were successful in keeping tainted seafood from reaching markets. However, effects of DWH closures on fisher decision making, fishery productivity, and distribution of fishing effort all remain poorly understood. Understanding the range and magnitude of fishers’ responses to perturbations — including regulatory change and human-induced environmental disasters — is critical for designing effective management and disaster response policies that can meet biological, ecological, economic, social, and sustainability objectives. This work characterized the spatial and temporal patterns of productivity and fishing effort for the Gulf of Mexico (GoM) commercial reef fish fishery. Patterns of productivity and effort distribution were used to examine the response of fishers to management change and large-scale disturbance, namely the DWH fishing closures. Fisheries-dependent logbook trip reports were used to quantify revenue and catch-per-unit-effort (CPUE) patterns from 2000-2014. Novel to fisheries work in the GoM, complementary vessel monitoring systems (VMS) satellite tracking data were used to quantify high-resolution spatial distribution patterns over time, relative to the DWH fishing closures. A general linear modeling (GLM) approach was also used to examine which variables may have contributed to resilience of fishers after DWH closures. Results suggested that this fishery was largely resilient to the DWH fishing closures in 2010, although exact outcomes varied by region. Overall fleet-level productivity steadily increased over time, but regional patterns were based on major species in catch. Productivity in the western GoM was consistently highest over time, and trips in the west and central GoM were dominated by Red snapper (Lutjanus campechanus) and Vermilion snapper (Rhomboplites aurorubens). Trips in the east were dominated by Red grouper (Epinephelus morio) and Gag grouper (Mycteroperca microlepis). Shifts in spatial distribution to new productive fishing grounds or reduced competition via fewer vessels or trips may explain the increases in productivity observed over the study period. Consolidation in the fleet was apparent, with fewer individual vessels and fewer total trips over time. However, the rate of vessel drop out after DWH (5%) was far below the annual background attrition rate of ~14-20%. Relative productivity patterns inside vs. outside the boundaries of fishing closures did not change over time, and there were even some increases in productivity observed during and after DWH in the eastern GoM. Yet, vessels that dropped out after DWH were concentrated in the north-central and eastern GoM. Distribution of fishing grounds before and after DWH were highly similar, and there were increases in effort along the outer West Florida Shelf. Variability in revenue and CPUE, CPUE magnitude, and magnitude of grouper landings were significant predictors of dropping out of the fishery in the GLMs. Synergies with the Red snapper or Grouper-Tilefish IFQs may have “primed” the fishery for resilience by eliminating inconsistent or marginal fishers before the oil spill, and may further explain some of the spatially varying patterns of productivity and attrition after 2010. Resilience was likely also enhanced by the more than $2 billion in emergency compensation payments made to captains, crew, and vessel owners for lost fishing income and assistance with oil remediation efforts. This work stands to make a significant contribution to our understanding of how the DWH oil spill impacted fisheries and communities in the GoM. The results add to a growing body of literature suggesting that the acute population- and ecosystem-level impacts of the DWH oil spill were not as strong or severe as initially anticipated. This work also stands to make contributions to the broader understanding of how this fishery has performed in the wake of recent management change and major environmental disturbance.

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