O turismo tem apresentado uma demanda mundial cada vez maior e, por conseguinte, há uma crescente necessidade de preservar o meio ambiente com vistas às gerações futuras. O geoturismo e a roteirização, são ferramentas que podem ser utilizadas para este fim. Este trabalho visa, portanto, integrar dados turísticos, através do Sensoriamento Remoto com dados altimétricos representados por um Modelo Digital de Elevação - MDE. Desta forma, esta sistemática permite desenvolver um ambiente virtual onde o usuário pode realizar vôos cênicos em 3D (terceira dimensão) sobre o município de Três Cachoeiras e realizar, com isso um planejamento eficaz de suas atividades turísticas antes mesmo de ir a campo. Com a imagem de alta resolução espacial IKONOS (1m) sobreposta ao MDE é possível caracterizar a região e definir critérios, como por exemplo, a declividade do terreno para avaliar cada percurso. Estas ferramentas permitem, portanto, o estabelecimento de critérios de deslocamento e aos níveis de dificuldade para cada percurso. Os dados de campo, bem como aqueles provenientes da análise das imagens orbitais e do MDE, resultaram em uma roteirização turística sobre dois temas distintos: o Geoturismo e o Turismo Rural. / The tourism has presented a world-wide demand (2008). Representing an increasing necessity to preserve the environment with sights to the future generations, by the geotourism and the route planning, as well as the scientific research. This work aims at, therefore, to integrate tourist and de Remote sensing with altimetric data, represented by a Digital Elevation Model - DEM. In such a way, this systematics, allows to develop a virtual environment where the user can to visualize through scenic flights in 3D (third dimension) the city of Três Cachoeiras and make an efficient planning of tourist activities before exactly to go the field. With high resolution space image IKONOS (1m) overlapped to the DEM, is possible to characterize the region and to define criteria, as for example, the declivity of the land for evaluate each passage. These tools allow the establishment of criteria of displacement and the levels of difficulty for each passage. The field data, as well as those proceeding from the analysis of the orbital images and the DEM, had resulted in a touristic route on two distinct subjects: the Geotourism and the Rural Tourism.

O turismo tem apresentado uma demanda mundial cada vez maior e, por conseguinte, há uma crescente necessidade de preservar o meio ambiente com vistas às gerações futuras. O geoturismo e a roteirização, são ferramentas que podem ser utilizadas para este fim. Este trabalho visa, portanto, integrar dados turísticos, através do Sensoriamento Remoto com dados altimétricos representados por um Modelo Digital de Elevação - MDE. Desta forma, esta sistemática permite desenvolver um ambiente virtual onde o usuário pode realizar vôos cênicos em 3D (terceira dimensão) sobre o município de Três Cachoeiras e realizar, com isso um planejamento eficaz de suas atividades turísticas antes mesmo de ir a campo. Com a imagem de alta resolução espacial IKONOS (1m) sobreposta ao MDE é possível caracterizar a região e definir critérios, como por exemplo, a declividade do terreno para avaliar cada percurso. Estas ferramentas permitem, portanto, o estabelecimento de critérios de deslocamento e aos níveis de dificuldade para cada percurso. Os dados de campo, bem como aqueles provenientes da análise das imagens orbitais e do MDE, resultaram em uma roteirização turística sobre dois temas distintos: o Geoturismo e o Turismo Rural. / The tourism has presented a world-wide demand (2008). Representing an increasing necessity to preserve the environment with sights to the future generations, by the geotourism and the route planning, as well as the scientific research. This work aims at, therefore, to integrate tourist and de Remote sensing with altimetric data, represented by a Digital Elevation Model - DEM. In such a way, this systematics, allows to develop a virtual environment where the user can to visualize through scenic flights in 3D (third dimension) the city of Três Cachoeiras and make an efficient planning of tourist activities before exactly to go the field. With high resolution space image IKONOS (1m) overlapped to the DEM, is possible to characterize the region and to define criteria, as for example, the declivity of the land for evaluate each passage. These tools allow the establishment of criteria of displacement and the levels of difficulty for each passage. The field data, as well as those proceeding from the analysis of the orbital images and the DEM, had resulted in a touristic route on two distinct subjects: the Geotourism and the Rural Tourism.

Since 1992, the Swedish government and more specifically the Swedish Transport Administration (STA), has subsidized unprofitable flights in the country. Most of these flights are to remote towns in the northern half of the country in which alternative methods of transport are limited, and it is therefore argued that these flights need to be subsidized in order to make these towns easily accessible and to continue being economically stable. The purpose of this thesis is to determine whether or not the Swedish government should continue subsidizing unprofitable flight routes, or if it should subsidize some of the routes or simply none of them. This was done with a so-called cost-benefit analysis. The cost-benefit analysis comes to a conclusion that, likely, four out of the seven PSOs should be abolished, while three could possibly still be subsidized. However, since a cost-benefit analysis was used, it is difficult to test the result for statistical significance meaning the result is uncertain and open for discussion and future evaluation.

The Federal Aviation Administration (FAA) has been modernizing the United States' air transportation system within a series of initiatives called the Next Generation Air Transportation System (NextGen). The goal of NextGen is to increase the safety, efficiency, capacity, predictability, and resiliency of American Air Traffic Control (ATC) by implementing satellite-based communication, and navigation systems. Because of the vast oceanic areas controlled by Oakland, New York, and Anchorage air traffic control centers, improving oceanic operations is significant for the United States. According to the FAA, oceanic flights generate 31% of passenger revenue and 40% of cargo revenue in U.S.-controlled airspace. New NextGen procedures offer the opportunity for aircraft to save fuel consumption by allowing oceanic flights to fly at more efficient routes and flight levels. This dissertation investigates three areas to improve flight operations over oceanic airspace. The first area studies the operational benefits of providing satellite-based meteorological information to aircraft operating in remote and oceanic airspace. This research effort uses two approaches as follows: 1) statistical flight analysis, and 2) simulation-based analysis. The second area provides an optimization technique to improve the current procedures for assigning flights to the Organized Track System (OTS) in the Atlantic Ocean based on the Collaborative Decision Making (CDM) concept. The third area investigates the potential savings of "In-Trail Procedure" (ITP) as one of the advanced surveillance operations in the Pacific and Atlantic oceanic airspace. To quantify the operational benefits of the proposed procedures, a fast-time simulation tool, the Global Oceanic (GO) model, is developed and employed. The GO model is a microscopic flight simulation tool that has been developing by the Air Transportation Systems Laboratory at Virginia Tech offering realistic and inexpensive evaluations of novel technologies and procedures to improve flight operations over global oceanic airspace. the results of these studies are analyzed in terms of fuel consumption, travel distance, travel time, level of service, and potential air traffic controllers' workload. / Doctor of Philosophy / The economic growth and social connectivity of nations are highly correlated to effective and efficient air transportation systems. The Federal Aviation Administration (FAA) has initiated a program to modernize America's air transportation system and make flight operations safer, and more efficient. This program is called the Next Generation Air Transportation System (NextGen) and its goal is transforming the communication and navigation technologies to satellite-based systems. Improving oceanic flights is one of the main concerns of the NextGen program since the United States controls massive oceanic areas in the Atlantic and the Pacific Ocean. The FAA needs to evaluate the benefits and costs of advanced technologies and procedures to justify the NextGen initiatives. The FAA has employed computer simulation tools to support decisions for future infrastructure investments and encourage airlines to equip their aircraft with more advanced avionics. The Global Oceanic (GO) model is a microscopic flight simulation tool developed jointly by the Air Transportation Systems Laboratory at Virginia Tech and the FAA providing quick, realistic, and inexpensive evaluations of advanced procedures to improve flight operations over oceans. This dissertation investigates the operational benefit of three advanced procedures using the GO model. The areas to improve flight operations over oceanic airspace are as follows: 1) operational benefits of providing satellite-based meteorological information to aircraft operating in remote and oceanic airspace, 2) operational benefits of an optimization technique for flight assignments to the Organized Track System (OTS) in the Atlantic Ocean, 3) operational benefits of "In-Trail Procedure" (ITP) as one of the advanced surveillance operations in the Pacific and Atlantic oceanic airspace. These studies quantify the potential savings of these procedures in terms of reducing fuel consumption, travel distance, travel time, greenhouse gas emissions, and potential air traffic controllers' workload.

Not too long ago, commercial supersonic aircraft flights were part of the air transportation system. In the 1970's we had the Russian-built Tupolev Tu-144 and the BAC/Aerospatiale Concorde, the latest being tin operation for 27 years. The work documented in this dissertation focused on the viability of bringing back supersonic aircraft as a transportation mode. Throughout three years, Virginia Tech and a team from NASA have been combining efforts to develop a model capable of predicting future air travel demand for supersonic vehicles. The model can predict future supersonic commercial services and allows aircraft designers from NASA to optimize aircraft performance and characteristics by maximizing the potential air travel demand. The final product of this study was the development of the Low-Boom Supersonic Aircraft Model (LBSAM). The development progress took three years to be completed, and during each year, a version of the model with the preliminary predictions was made available to NASA. Each of the three versions of the model predicts future supersonic commercial services. What differentiates each version is the data, method, and aircraft type/design implemented; the latest version of the model is more realistic and provides a higher number of functionalities. The first version of the model predicted the possible supersonic commercial service for three aircraft types: each with two variations. An 18-seat, 40-seat, and 60-seat low-boom and non-low-boom aircraft were analyzed. The second version of the model analyzed a 20-seat and 40-seat low-boom, non-low-boom aircraft with restrictions and non-low-boom aircraft without restrictions. The latest version of the model tries to estimate potential demand for a 43-seat and a 52-seat supersonic low-boom aircraft design. The low-boom concept refers to the implementation of technology that reduces the loudness of a sonic boom. A non-low-boom concept refers to an aircraft flying faster than Mach 1 with the technology's implementation that reduces the loudness of a sonic boom. The final results suggest that for a 52-seat LBSA, the potential worldwide demand is as follows. • 33.4 million seats worldwide. Assuming an overland range of 3,200 nm., an overland Mach 1.7, and an overland fuel scale factor of 0.98. • 772 aircraft needed worldwide. Assuming an overland range of 2,800 nm., an overland Mach 1.7, and an overland fuel scale factor of 0.90. • 1,032 one-way OD pairs where LBSA can operate. Assuming an overland range of 2,800 nm., an overland Mach 1.7, and an overland fuel scale factor of 0.90. The LBSAM is mainly driven by the cost per passenger mile values calculated for each one-way Origin-Destination (OD) pair. Additional uncertainties in the model include the market share and annual aircraft utilization. The market share refers to the percent of the demand that will switch from current subsonic commercial services to commercial supersonic services. During the three-year work, we considered a market share of 50% and 100%. Aircraft utilization refers to the number of hours that the airline will be able to use the aircraft. The majority of the projections were based on a 3,500-hour aircraft utilization. / Doctor of Philosophy / Not too long ago, commercial supersonic aircraft flights were part of the air transportation system. An aircraft flying faster than the speed of sound is known as an aircraft flying at supersonic speed. Current commercial aircraft fly at subsonic speed. Subsonic speed refers to aircraft flying at a speed lower than the speed of sound. In the 1970's we had the Russian-built Tupolev Tu-144 and the BAC/Aerospatiale Concorde, the latest being tin operation for 27 years. The work documented in this dissertation focused on the viability of bringing back supersonic aircraft as a transportation mode. Throughout three years, Virginia Tech and a team from NASA have been combining efforts to develop a model capable of predicting future air travel demand for supersonic vehicles. The model can predict future supersonic commercial services and allows aircraft designers from NASA to optimize aircraft performance and characteristics by maximizing the potential air travel demand. The purpose of this dissertation effort is to provide a better understanding of what could be the potential commercial demand for supersonic flight in the near future. We consider all the benefits and characteristics of supersonic flight and studied in detail what percentage of the travelers might be willing to migrate from the current subsonic market to the supersonic market. We estimated this ratio by studying the spending behavior of passengers in the current market. How much more are passengers willing to pay to save time? We can infer how much travelers value their time by comparing direct flights versus flights with an intermediate stop. The results show that a demand of 33.4 million seats could be reached by the year 2040. The supersonic market would consist of more than one thousand one-way origin-destination pairs worldwide, and more than seven hundred supersonic aircraft are expected to satisfy the forecast demand.

Path integral approaches have been widely used for long in both quantum mechanics as well as statistical mechanics. In addition to being a tool for obtaining the probability distributions of interest(wave functions in the case of quantum mechanics),these methods are very instructive and offer great insights into the problem. In this thesis, path integrals are extensively employed to study some very interesting problems in both equilibrium and non-equilibrium statistical mechanics. In the non-equilibrium regime, we have studied, using a path integral approach, a very interesting class of anomalous diffusion, viz. the L´evy flights. In equilibrium statistical mechanics, we have evaluated the partition function for a class of molecules referred to as the hindered rotors which have a barrier for internal rotation. Also, we have evaluated the exact quantum statistical mechanical propagator for a harmonic potential with a time-dependent force constant, valid under certain conditions. Diffusion processes have attracted a great amount of scientific attention because of their presence in a wide range of phenomena. Brownian motion is the most widely known class of diffusion which is usually driven by thermal noise. However ,there are other classes of diffusion which cannot be classified as Brownian motion and therefore, fall under the category of Anomalous diffusion. As the name suggests, the properties of this class of diffusion are very different from those for usual Brownian motion. We are interested in a particular class of anomalous diffusion referred to as L´evy flights in which the step sizes taken by the particle during the random walk are obtained from what is known as a L´evy distribution. The diverging mean square displacement is a very typical feature for L´evy flights as opposed to a finite mean square displacement with a linear dependence on time in the case of Brownian motion. L´evy distributions are characterized by an index α where 0 <α ≤ 2. When α =2, the distribution becomes a Gaussian and when α=1, it reduces to a Cauchy/Lorentzian distribution. In the overdamped limit of friction, the probability density or the propagator associated with L´evy flights can be described by a position space fractional Fokker-Planck equation(FFPE)[1–3]. Jespersen et al. [4]have solved the FFPE in the Fourier domain to obtain the propagator for free L´evy flight(absence of an external potential) and L´evy flights in linear and harmonic potentials. We use a path integral technique to study L´evy flights. L´evy distributions rarely have a compact analytical expression in the position space. However, their Fourier transformations are rather simple and are given by e−D │p│α where D determines the width of the distribution. Due to the absence of a simple analytical expression, attempts in the past to study L´evy flights using path integrals in the position space [5, 6] have not been very successful. In our approach, we have tried to make use of the elegant representation of the L´evy distribution in the Fourier space and therefore, we write the propagator in terms of a two-dimensional path integral –one over paths in the position space(x)and the other over paths in the Fourier space(p). We shall refer to this space as the ‘phase space’. Such a representation is similar to the Hamiltonian path integral of quantum mechanics which was introduced by Garrod[7]. If we try to perform the path integral over Fourier variables first, then what remains is the usual position space path integral for L´evy flights which is rather difficult to solve. Instead, we perform the position space path integral first which results in expressions which are rather simple to handle. Using this approach, we have obtained the propagators for free L´evy flight and L´evy flights in linear and harmonic potentials in the over damped limit [8]. The results obtained by this method are in complete agreement with those obtained by Jesepersen et al. [4]. In addition to these results, we were also able to obtain the exact propagator for L´evy flights in a harmonic potential with a time-dependent force constant which has not been reported in the literature. Another interesting problem that we have considered in the over damped limit is to obtain the probability distribution for the area under the trajectory of a L´evy particle. The distributions, again, were obtained for free L´evy flight and for L´evy flights subjected to linear and harmonic potentials. In the harmonic potential, we have considered situations where the force constant is time-dependent as well as time-independent. Like in the case of the over damped limit, the probability distribution for L´evy flights in the under damped limit of friction can also be described using a fractional Fokker-Planck equation, although in the full phase space. However, this has not yet been solved for any general value of α to obtain the complete propagator in terms of both position and velocity. Using our path integral approach, the exact full phase space propagators have been obtained for all values of α for free L´evy flights as well as in the presence of linear and harmonic potentials[8]. The results that we obtain are all exact when the potential is at the most harmonic. If the potential is higher than harmonic, like the cubic potential, we have used a semi classical evaluation where, we extremize the action using an optimal path and further, account for fluctuations around this optimal path. Such potentials are very useful in describing the problem of escape of a particle over a barrier. The barrier crossing problem is very extensively studied for Brownian motion (Kramers problem) and the associated rate constant has been calculated in a variety of methods, including the path integral approach. We are interested in its L´evy analogue where we consider the escape of a particle driven by a L´evy noise over a barrier. On extremizing the action which depends both on phase space variables, we arrived at optimal paths in both the position space as well as the space of the conjugate variable, p. The paths form an infinite hierarchy of instant on paths, all of which have to be accounted for in order to obtain the correct rate constant. Care has to be taken while accounting for fluctuations around the optimal path since these fluctuations should be independent of the time-translational mode of the instant on paths. We arrived at an ‘orthogonalization’ scheme to perform the same. Our procedure is valid in the limit when the barrier height is large(or when the diffusion constant is very small), which would ensure that there is small but a steady flux of particles over the barrier even at very large times. Unlike the traditional Kramers rate expression, the rate constant for barrier crossing assisted by L´evy noise does not have an exponential dependence on the barrier height. The rate constant for wide range of α, other than for those very close to α = 2, are proportional to Dμ where, µ ≈ 1 and D is the diffusion constant. These observations are consistent with the simulation results obtained by Chechkin et al. [9]. In addition, our approach when applied to Brownian motion, gives the correct dependence on D. In equilibrium statistical mechanics we have considered two problems. In the first one, we have evaluated the imaginary time propagator for a harmonic oscillator with a time-dependent force constant(ω2(t))exactly, when ω2(t) is of the form λ2(t) - λ˙(t)where λ(t) is any arbitrary function of t. We have made use of Hamiltonian path integrals for this. The second problem that we considered was the evaluation of the partition function for hindered rotors. Hindered rotors are molecules which have a barrier for internal rotation. The molecule behaves like free rotor when the barrier is very small in comparison with the thermal energy, and when the barrier is very high compared to thermal energy, it behaves like a harmonic oscillator. Many methods have been developed in order to obtain the partition function for a hindered rotor. However, most of them are some what ad-hoc since they interpolate between free-rotor and the harmonic oscillator limits. We have obtained the approximate partition function by writing it as the trace of the density matrix and performing a harmonic approximation around each point of the potential[10]. The density matrix for a harmonic potential is in turn obtained from a path integral approach[11]. The results that we obtain using this method are very close to the exact results for the problem obtained numerically. Also, we have devised a proper method to take the indistinguishability of particles into account in internal rotation which becomes very crucial while calculating the partition function at low temperatures.

Orientador: Maria Cristina Dias Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-26T08:28:58Z (GMT). No. of bitstreams: 1 Garcia_AthosPovoa_M.pdf: 9594597 bytes, checksum: c99eaf2e0c3c48d6e04df60e99d62937 (MD5) Previous issue date: 2014 / Resumo: Este trabalho apresenta uma metodologia para a obtenção dos parâmetros sustentados do arco elétrico, especificamente a corrente de condução e a corrente de deslocamento. Os resultados apresentados são provenientes da análise de 410 ensaios realizados em ambiente não confinado de um trecho experimental de linha de transmissão aérea de 500 kV , composta por três torres e dois vãos. Foram analisados diversos níveis de corrente entre 15 Aef e 10 kAef. O método apresentado é baseado na obtenção de um novo elemento para a caracterização do arco elétrico, a capacitância. Verifica-se que existe um atraso da forma de onda da tensão entre os terminais do arco em relação à forma de onda da corrente do arco elétrico próximo ao cruzamento das curvas pelo zero. Este comportamento indica uma resposta a um circuito que não pode ser considerado puramente resistivo, mas sim composto por uma resistência e uma capacitância. Desta forma a contribuição da presente pesquisa consiste na identificação da capacitância do arco elétrico. Os resultados obtidos mostram que a utilização da metodologia desenvolvida é eficaz para a obtenção dos parâmetros sustentados do arco elétrico e que tais parâmetros possuem uma relação de proporcionalidade em relação aos níveis de corrente do arco elétrico / Abstract: This work presents a methodology to obtain the stationary parameters of the electric arc, specifically the conductive current and the displacement current. The results presented are from analysis by 410 assays performed at field tests of a test section of 500 kV transmission line. The section is formed by three transmission towers, one anchor tower positioned between two suspension towers. This work presents the analysis of tests with current levels between 15 Arms and 10 kArms. The presented method is based on obtaining a new element to characterize the arc, the capacitance. It is verified that there is a delay of the waveform of the voltage across the arc terminals relative to the waveform of the current arc near zero crossing. This behavior indicates that the arc can not be considered purely resistive, but instead it has a behavior of a parallel resistance and a capacitance impedance. Therefore the contribution of this research is to identify the capacitance of the electric arc. The results show that the use of the developed methodology is effective for obtaining the stationary parameters of the electric arc and that these parameters have a relationship of proportionality in relation to the arc current range.winz / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientador: Maria Cristina Dias Tavares / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T11:02:17Z (GMT). No. of bitstreams: 1 Santos_GilmarioBarbosa_D.pdf: 14752419 bytes, checksum: b5450debd9ddfb2a4a50a26c4b326901 (MD5) Previous issue date: 2012 / Resumo: O comprimento do arco elétrico é um parâmetro importante para a modelagem matem ática do arco elétrico. O perfil da variação do comprimento do arco atualmente é estimado pela análise da tensão medida entre os terminais do arco e da corrente do arco. Porém esses resultados não são conclusivos, pois não apresentam uma medição (escala métrica) do eixo-médio tridimensional do arco elétrico. Por outro lado, as imagens da evolução do arco podem fornecer informação suficiente à reconstrução do seu eixo tridimensional e à estimativa do comprimento do arco a cada instante, determinando uma curva de variação do comprimento. A principal contribuição deste trabalho, portanto, reside na obtenção da estimativa do comprimento do arco e, por conseguinte, do alongamento de arcos elétricos baseada na aplicação do modelo snake-3D na reconstrução tridimensional dos eixos longitudinais de arcos elétricos gerados artificialmente. Foram realizados diferentes experimentos para avaliar a proposta de aplicação da snake-3D. Inicialmente, algumas características geométricas dos arcos foram reproduzidas em curvas paramétricas cujas projeções, sobre seções de planos, formaram as sequências de pares de imagens e determinaram os conjuntos de casos experimentais. Em seguida os resultados obtidos através da aplicação da snake-3D foram analisados comparativamente a outros métodos de reconstrução 3D frente aos valores verdadeiros dos comprimentos das curvas. Também foram realizados experimentos com um objeto concreto, nesse caso, um neon flexível manipulado defronte a um par de câmeras reais. As matrizes de calibração foram determinadas por meio de procedimento específico, o comprimento verdadeiro do objeto foi estimado por meio de medição direta e comparado aos resultados obtidos através da aplicação da snake-3D e outro método de reconstrução 3D. Em seguida a snake-3D foi aplicada a imagens de arcos elétricos reais cuja evolução foi capturada utilizando câmeras reais. Nesses casos as estimativas dos comprimentos por meio de snake-3D foram contrapostas aos estudos baseados na análise dos sinais de tensão e de corrente medidos nas extremidades do arco em evolução. Os comprimentos obtidos com a abordagem proposta foram semelhantes aos obtidos através de medidas elétricas, o que valida o uso da metodologia desenvolvida para este tipo de aplicação / Abstract: The electrical arc length is an important parameter for the arc mathematical modeling. Nowadays the profile of the arc length variation is estimated by the analysis of the voltage measured at the extremities of the arc and the current of the arc. But these results are not conclusive because they do not present a metrical measurement of the three-dimensional medial-axis of the arc. On the other hand, the images of the spatial evolution of the arc can provide enough resources for recovering the 3D longitudinal axis for estimation of the arc length as well as for obtaining the curve of length variation along the time. The main contribution of this work therefore lies in the estimation of the arc length, and consequently the elongation of electric arcs based on the application of the model (3D-snake) for the three-dimensional reconstruction of the longitudinal axes of artificially generated electrical arcs. Different experiments were conducted to evaluate the proposed application of the 3D-snake. Initially, some geometrical characteristics of the arcs were reproduced in parametric curves whose projections formed sequences of image pairs and determined the sets of test cases. Then the results obtained by applying the 3D-snake were analyzed in comparison to other 3D reconstruction methods against the true values of the lengths of curves. Also experiments were performed with a concrete object, in this case, a flexible neon manipulated in front of a pair of real cameras. The calibration matrices were determined by specific procedure, the length of the real object was estimated by direct measurement and compared to results obtained by applying the 3D-snake and other 3D reconstruction method. Next the 3D-snake was applied to real images of arcs whose evolutions were captured using real cameras. In these cases the estimation of measurement through 3D-snake were opposed to results based on arc current and arc voltage measured at arc terminals. The lengths obtained with the proposed model were similar to those obtained through electrical measurements, which validates the use of the method developed for this type of application / Doutorado / Engenharia de Computação / Doutor em Engenharia Elétrica

Orientador: Maria Cristina Dias Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T16:31:47Z (GMT). No. of bitstreams: 1 Talaisys_JonasLemos_M.pdf: 12385917 bytes, checksum: 5619a3284121ab56d2a0a337ef2456b4 (MD5) Previous issue date: 2012 / Resumo: Este trabalho apresenta resultados do estudo do conteúdo harmônico e da variação do comprimento de arcos elétricos longos, com comprimento inicial superior a 4 m. Os resultados decorreram da análise de uma grande quantidade de dados obtidos de 647 ensaios realizados em ambiente não confinado em um trecho experimental de linha de transmissão aérea de 500 kV. Diversos níveis de corrente de arco foram abrangidos, desde 15 Aef até 10.000 Aef. O conteúdo harmônico da tensão e da corrente dos arcos foi analisado através da Trans-formada de Fourier Discreta em Tempo Reduzido. Mediante um tratamento estatístico, este conteúdo harmônico possibilitou a consolidação da assinatura harmônica dos arcos estudados. Uma contribuição importante da pesquisa consiste na verificação de que o conteúdo harmônico do arco pode ser utilizado para identificar o momento a partir do qual o arco elétrico se encontra com suas características elétricas estabilizadas. A partir deste instante os parâmetros elétricos do arco podem ser utilizados para obtenção de um modelo matemático. Utilizando-se do conteúdo harmônico e de registros visuais, a variação de comprimento foi obtida para 69 arcos. Esta análise inicial permite que se tenha uma noção da velocidade de alongamento destes arcos em relação ao seu nível de corrente. Permitiu também a obtenção de um gradiente de tensão mais preciso dos arcos, considerando-se tanto o alongamento quanto a estabilidade destes. Por fim, este trabalho tem por objetivo apresentar resultados que forneçam características e informações relevantes à obtenção de um modelo matemático de arco elétrico secundário adequado para o estudo da Manobra de Abertura e Religamento Monopolar. O conteúdo harmônico é identificado como uma ferramenta eficaz para caracterização da estabilidade destes arcos e o alongamento é um dos principais fatores relacionados com a extinção e duração do arco secundário / Abstract: This document presents results related to harmonic content and length variation of long electrical arcs in air, with initial length of 4 m. The results are based in the analysis of a data-base containing 647 experiments in non-confined environment of an experimental aerial 500 kV transmission line. The current range analyzed lies between 15 Arms and 10,000 Arms. The harmonic contents of voltage and current of electrical arcs were analyzed by the Short Time Discrete Fourier Transform. Using a statistic treatment this harmonic content allowed to consolidate the harmonic signature of the arcs in study. Furthermore, in the present work it was proposed that the harmonic content of an electrical arc defines the moment when the electric arc has its electrical characteristics stabilized. This instant is crucial to obtain the correct arc electrical parameters that will used to represent the arc. Using the harmonic content and visual data, the variation in length was obtained for 69 arcs. This initial analysis lead to arc elongation velocity regarding the current level and permit-ted to obtaining a more precise arc voltage gradient, considering both elongation as its stability. Finally, this work aims to supply relevant characteristics and information to obtaining a secondary arc model useful to the Single-Phase Autoreclosing Maneuver study. The harmonic content is an efficient way to characterize these arcs and the arc elongation is one of the main factors related to the duration and self-extinction of the secondary arc / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

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