Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 88 pages. Includes vita. Includes bibliographical references.

Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 42 pages. Includes vita. Includes bibliographical references.

Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 44 pages. Includes vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed Aug. 2, 2007). PDF text: xviii, 388 p. : ill. UMI publication number: AAT 3258404. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 107-112). Also available via the Internet.

Made available in DSpace on 2015-03-03T11:52:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-22Bitstream added on 2015-03-03T12:06:49Z : No. of bitstreams: 1 000802248.pdf: 1455012 bytes, checksum: 1ff27825cc53baa7bf760b7595037fde (MD5) / O Brasil possui um grande potencial no setor do agronegócio e a associação desse setor com o desenvolvimento tecnológico deu origem à Agricultura de Precisão. Nesse contexto, o uso de sensores de Nitrogênio foliar de tempo real, especificamente os que utilizam como princípio de funcionamento e espectrometria, em conjunto com sistemas inteligentes computacionais, tem contribuído de forma decisiva para o incremento da produtividade no campo, evitando a aplicação excessiva de insumos e, assim, preservando o meio ambiente. Um insumo comumente aplicado na cultura de cana-de-açúcar é o Nitrogênio que, apesar de ter grande contribuição econômica, impõe grande impacto ao meio ambiente, principalmente na poluição de aquíferos e mananciais. Dessa maneira, a quantidade aplicada desse nutriente é de grande importância, pois sua falta limita o crescimento da cultura e seu excesso polui o meio ambiente. A determinação da quantidade de Nitrogênio pode ser feita por meio do uso de sensores espectrométricos na faixa do infravermelho próximo visando a cobertura verde da cultura. Entretanto, no estágio inicial de crescimento, a cobertura verde não é plena, de forma que o sensor detecta, além da cobertura verde, o solo e cobertura morta, acrescentando ruído à medida da refletância usada para a estimação do teor de Nitrogênio na planta. Nesse cenário, este trabalho tem o objetivo de mapear a relação entre os valores fornecidos pelo sensor N-SENSOR ALS do fabricante norueguês YARA e os teores reais de Nitrogênio na planta medidos em laboratório. Mais especificamente, sistema de inferência neuro-fuzzy adaptativo (ANFIS), redes neurais artificiais do tipo Perceptron de Múltiplas Camadas (PMC) e General Regression Neural Network (GRNN) serão empregados visando a identificação e o aprendizado da relação entre os valores medidos pelo sensor N-SENSOR ALS e os valores reais obtidos em laboratório, eliminando os ruídos... / Brazil has a great potential in the agribusiness sector and the association of this sector with technological development gave rise to precision agriculture. In this context, the use of soil sensors for real-time, specifically those using operating principle as spectrometry, together with computational intelligent systems are contributing decisively to increasing productivity in the field, avoiding excessive use of inputs and thus preserving the environment. An ingredient commonly used in the cultivation of sugar cane is the nitrogen that, depite great economic contribution, imposes great impact on the environment, especially in aquifers and fountains pollution. Thus, the applied amount of this nutrient is of great importance, since the lack of limits crop growth and excess pollute the environment. The determination of the nitrogen content can be made through the use of spectrometric sensors in the near-infrared aiming the green cover crop. However, in the initial stage of growth the green coverage is not complete, so the sensor sees beyond the green cover, soil and mulch, adding noise to the measurement of reflectance used to estimate the percentage of nitrogen in plant. In this scenario, this paper aims to map the relationship between the values provided by the sensor N-SENSOR ALS Norwegian YARA manufacturer and the actual levels of nitrogen in the plant measured in the laboratory. More specifically, systems of inference adaptive neuro-fuzzy (ANFIS), artificial neural network Multilayer Perceptron type (MLP) and General Regression Neural Network (GRNN) are employed in order to identify learning and the relationship between the values measured by the sensor N-SENSOR ALS and actual obtaind in the laboratory, eliminating the noise imposed by non-green roof and external disturbances such as the variation of ambient light. The results indicate that the neuro-fuzzy approach has superior performance and neural networks can be used to correct...

Orientador: Jose Ricardo Pelaquim Mendes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-12T14:15:08Z (GMT). No. of bitstreams: 1 Melo_AndreVerasde_M.pdf: 5529810 bytes, checksum: 4537025b6d5ddedffce982368776dbbd (MD5) Previous issue date: 2008 / Resumo: O cenario de producao em campos de petroleo tem apresentado nos anos recentes condicoes cada vez mais severas e complexas. Muitas descobertas em regioes de maior profundidade e com formacoes geologicas mais diversas tem demandado solucoes tecnológicas que beiram a fronteira do conhecimento, de forma que a producao tem andado lado a lado com o desenvolvimento de novas tecnologias. Assim, a necessidade do aumento do fator de recuperação para justificar os investimentos nestas condicoes sao desafios presentes nos novos projetos de pocos, de elevacao artificial e de recuperacao secundaria, o que vem levando ao desenvolvimento de solucoes submarinas e integradas, como o caso do separador submarino VASPS. No entanto, o controle de processos continuos, como a vazao de producao, a temperatura e a pressao, ainda e tratado da mesma forma que era feito quando do comeco da producao offshore em campos de oleo leve. Este trabalho visa permitir a melhoria de desempenho operacional do sistema VASPS, mensurada pelos custos totais gerados pelo sistema e pelos proventos gerados na producao de oleo e gas, bem como propor novas metodologias de sistemas de controle para sistemas similares, utilizando tecnologias recentes de controle inteligente. Vale ressaltar que o problema de controle e atualmente tratado em campo com solucoes de automacao, sem o estudo devido, causando danos a equipamentos que exigem intervencoes custosas. Os controladores propostos neste trabalho visam minimizar os esforcos aos quais estes atuadores estao expostos, provendo uma maior vida util as tecnologias de elevacao artificial de alta vazão e podendo ser aplicado de forma modular a outros processos relacionados. / Abstract: The oil production scenario has been becoming more and more complex and severe in the recent years. Plenty discoveries in deeper and more diversified formations have been requiring cutting edge technological solutions., such that the production has been deployed side by side with the technological development. Thus, the need for the enhancement of the recuperation factor in order to justify the investment in these new conditions are actual challenges within the recent design of wells, artificial lift systems and secondary recuperation projects, which has been leading to the development towards subsea integrated solutions, such as the VASPS subsea separator. However, the control of continuous processes, i.e. flow, temperature and pressure, is still dealt the same way it was done when the offshore production in light oil fields began. This work envisions the enhancement of the operational performance of the VASPS system, measured as a function of the total costs implied by the technology, altogether with the receipts generated in the gas and oil production, as well as the delivering of new methodologies for the design of controllers using late technologies of intelligent control. Also, it is worth recalling that nowadays the control task is dealt with automation solutions, without the proper handling, causing failures in equipments that require expensive rig intervention for workover. The controllers proposed in this work are designed to minimize the control effort, to which these actuators are exposed, providing extended lifetime to the high level production artificial lift technologies, being also able to be applied to other related processes in a modular form. / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo

This thesis proposes a novel framework for solving the energy management problem of Hybrid Electric Vehicles (HEVs). We aim to establish a practical and effective approach targeting an optimal Energy Management Strategy (EMS). A situation-specific Equivalent Consumption Minimization Strategy (ECMS) is developed to minimize fuel consumption and improve battery charge sustainability while maintaining an acceptable drive quality. The investigated methodology will be broadly applicable to all HEV applications; however, it will be well-suited for hybrid electric delivery applications. / Thesis / Master of Applied Science (MASc)

Repetitive control (RC) was proven to enable high performance for systems that are subject to periodically repeating signals by enhancing an existing feedback control system so that it produces zero tracking error to a periodic command, or zero tracking error in the presence of a periodic disturbance of known period. Periodic signals are very common in many applications like robotics, disk drive systems, power converters, photolithography, jitter or vibration elimination in spacecraft and many more. Due to the growth in micro-processor and micro-controller technologies, most of the controllers are implemented in digital domain. Digital RC is typically designed by assuming a known constant period of command/disturbance signal, which then leads to the selection of a fixed sampling period that keeps it synchronized with the command/disturbance signal. However, in practice, the period for these signals might not be accurately known or might vary with time. In order to overcome this problem, higher order RC (HORC) was proposed as one method to make RC less sensitive to period error or period fluctuations. This dissertation investigates HORC, specifically second and third order RC designs (SORC and TORC), to identify the limitations, gaps, and design tradeoffs that a control system designer faces. New designs and methods are developed to address such gaps including stability, designer tradeoffs, robustness and other related performance characteristics. This dissertation has three major parts: SORC designs and stability, SORC design tradeoffs, and TORC designs and stability.

Growing congestion problems of many metropolitan areas which cause excessive traffic delay, instability of travel time generated the need for the development of an Intelligent Vehicle Highway System (IVHS) program that is capable of making significant improvements in mobility, highway safety, and productivity on highways and urban streets. The success of such real time control system highly depends on the new methods that address dynamic traffic assignment. Thus there is an urgent need for an effective dynamic assignment model. The main objective of this research is to emphasize the importance of dynamic traffic assignment for Advanced Driver Information Systems (ADIS) which is one of the major components of IVHS and to present a practical traffic assignment model that is capable of running in real time and which can accurately predict link travel times, queue build up, and network performance. DYNTRAS (DYNamic Traffic Simulation Assignment), a simulation /assignment model is developed. The model uses an incremental loop that assigns a portion of the Origin-Destination matrix, and simulates the movement of the vehicles. Then, it updates travel times and assigns an additional portion of the O-D matrix. In contrast to traditional traffic assignment models like "capacity restraint" and “incremental assignment" techniques that do not consider time dimension, DYNTRAS incorporates time as a third dimension by keeping track of the vehicle movements in time. As a result, it is capable of predicting time-dynamic impacts of congestion and effects of diverted traffic on traffic flow more realistically. The model is applied to a test network. “Several experimental factors are varied to test the sensitivity of the model. The results obtained are presented and general conclusions are derived. The differences between dynamic and static traffic assignment results are also discussed by considering results obtained from both methods. The model needs to be calibrated using real traffic data. According to the results obtained, it needs to be validated. In addition, its long computation time should be reduced to be able to use it for real time applications. / Master of Science