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[pt] Encontrar manualmente uma boa função de transferência para visualização volumétrica é uma tarefa difícil que exige um conhecimento prévio sobre os dados sendo visualizados. Por isso, muitas pesquisas têm sido desenvolvidas nos últimos anos, com o objetivo de facilitar esse processo. No entanto, poucos trabalhos se esforçaram em obter métodos automáticos para a detecção de funções de transferência. A grande maioria busca melhorar o controle do usuário sobre a função de transferência indicando regiões potencialmente interessantes em histogramas e facilitando sua manipulação através de interfaces. Além disso, os resultados encontrados são geralmente apresentados na área médica, buscando melhorar a visualização dos exames de ressonância magnética, tomografia computadorizada ou ultrassom. Assim, visando mostrar que os conceitos utilizados nesses trabalhos podem ser explorados na área de petróleo e gás, este trabalho propõem um novo método para detecção automática de funções de transferência com o intuito de visualizar as interfaces entre regiões de um reservatório de petróleo. A abordagem proposta também é avaliada na detecção de fronteiras entre diferentes materiais de volumes médicos e outros volumes científicos amplamente utilizados. / [en] Finding a good transfer function for volume rendering is a difficult task that requires previous knowledge about the data domain itself. Therefore, many researches have been developed in the past few years aiming to overcome this barrier. However, only a few of them have concentrated forces into obtaining an automatic transfer function detector. Most of them focus on improving user control over transfer function domain, indicating potentially interesting regions and easing its manipulation through different histograms. Also, the results are often presented in medical field, through MRI, CT scan or ultrasound images. Thus, with the purpose of showing that the concepts used in these works can be exploited on oil and gas research field, this work proposes a novel method to automatically detect transfer functions, aiming to visualize the interfaces between different regions in the reservoir. The proposed approach is also tested in detecting boundaries between different materials of medical datasets and other datasets widely used.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2005. / Due to a more densely packed frequency spectrum, there is an increasing demand for narrow band filters with asymmetrical transfer function characteristics. The resulting coupling matrices contain both positive and negative couplings, cross couplings and individual resonator frequency offsets.

Magistro baigiamajame darbe tiriamos nevienalyčių plačiajuosčių periodinių sistemų užtvarinės savybės. Aptariamos periodinės sistemos ir jų charakteristikų skaičiavimo metodai. Nevienalyčių periodinių savybių tyrimui panaudoti du modeliai. Pradžioje nagrinėjamos periodinės ilgosios linijos savybės, vėliau taikomas spiralinės sistemos modelis. Modelių analizė atliekama klasikiniu, matriciniu ir daugialaidžių linijų metodais. Taikomas kompiuterinis modeliavimas. Sudarytos įėjimo varžos, perdavimo ir lėtinimo koeficientų, vėlinimo laikų bei pereinamosios charakteristikos skaičiavimo programos. Parodyta, kad linijos su periodiniais netolygumais įgyja užtvarinio filtro savybes, kurios ryškėja, didėjant sistemos nevienalytiškumui. / In order to reveal general properties of the structures, containing periodical inhomogeneities, the inhomogeneous electromagnetic line and the inhomogeneous helical retard structure are considered. The overview of periodical systems and methods of their analysis are presented. The structures, containing periodical inhomogeneities, are analyzed using classical, matrix and multiconductor line methods. The programs for calculation of line input impedance, transfer coefficient, delay coefficient and width of the stop-band are developed. The results show that the stop–band appears due to periodical inhomogeneities and the width of the stop-band and the attenuation in it depend on intensities of periodical inhomogeneities.

A measurement of the mass of the top quark is presented, using top-antitop pair (t-tbar) candidate events for the lepton+jets decay channel. The measurement makes use of Tevatron proton-antiproton collision data at centre-of-mass energy 1.96 TeV, collected at the CDF detector. The top quark mass is measured by employing an unbinned maximum likelihood method where the event probability density functions are calculated using signal (t-tbar) and background (W+jets) matrix elements, as well as a set of parameterised jet-to-parton mapping functions. The likelihood function is maximised with respect to the top quark mass, the fraction of signal events, and a correction to the jet energy scale (JES) of the calorimeter jets. The simultaneous measurement of the JES correction (ΔJES) provides an in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using 578 lepton+jets candidate events corresponding to 3.2 inverse femtobarns of integrated luminosity, the top quark mass is measured to be 172.4 ± 1.4(stat+ΔJES) ± 1.3(syst) GeV/c², one of the most precise single measurements to date.

Les réglementations toujours plus drastiques sur les émissions de polluants ont conduit au développement de systèmes de combustion opérant en régimes pauvres qui sont malheureusement sujet aux instabilités thermo acoustiques. La capacité de la Simulation aux Grandes Echelles (SGE) à simuler des turbines à gaz industrielles complexes de grande puissance est mise en évidence au cours de ce travail de thèse. Tout d’abord, la SGE est appliquée à un brûleur académique et validée par comparaison à des mesures effectuées à l’Université de Berlin ainsi qu’à des simulations SGE effectuées avec OpenFOAM chez Siemens. Afin de déterminer la stabilité de ce bruleur le couplage entre l’acoustique et la combustion est modélisé par l’approche de type fonction de transfert de flamme (FTF). Suite à ces calcules et l’évaluation de la FTF les fluctuations du nombre de swirl sont identifiées comme un paramètre à même de modifier cette réponse de flamme. Après cette première étape de validation, une turbine à gaz industrielle est simulée en SGE pour deux géométries différentes du brûleur et pour deux points de fonctionnement. La FTF issue de ces calculs est peu influencée par les deux points de fonctionnement. A l’inverse, des légères modifications de la géométrie du swirler modifient les caractéristiques de la FTF montrant que plusieurs mécanismes sont en jeu. Ces mécanismes sont identifiés comme étant la vitesse d’entrée, les fluctuations de swirl et les fluctuations de fraction de mélange. Cette dernière est causée par: 1) la pulsation du débit de carburant injecté et 2) la trajectoire fluctuante des jets de carburant. Bien que le swirler soit conçu pour fournir un mélange le plus homogène possible, d’importantes hétérogénéités de mélange à l’entrée de la chambre de combustion sont présentes. Les perturbations de mélange se combinent avec les fluctuations de vitesse (et donc avec les fluctuations de swirl) aboutissant à des résultats de FTF différents. Un modèle étendu pour la FTF reliant le dégagement de chaleur à la vitesse d’entrée et à la fluctuation de fraction de mélange (modèle MISO) se révèle être une bonne solution pour ces systèmes complexes. Une analyse non linéaire montre en outre que l’amplitude de forçage conduit non seulement à une saturation de la flamme, mais aussi à un changement de la réponse de flamme. La saturation de la flamme n’est vérifiée que pour la FTF globale et le gain augmente localement avec une amplitude croissante. Pour ce système on notera enfin que la flamme linéaire, comme la flamme non linéaire, ne sont pas compactes: certaines zones pourtant situées l’une à coté de l’autre, ont des différences significatives de délai de FTF, montrant que certaines parties de la flamme amortissent l’excitation alors que d’autres l’amplifient. / Modern pollutant regulation have led to a trend towards lean combustion systems which are prone to thermo-acoustic instabilities. The ability of Large Eddy Simulation (LES) to handle complex industrial heavy-duty gas turbines is evidenced during this thesis work. First, LES is applied to an academic single burner in order to validate the modeling against measurements performed at TU Berlin and against OpenFoam LES simulations done at Siemens. The coupling between acoustic and combustion is modeled with the Flame Transfer Function (FTF) approach and swirl number fluctuations are identified changing the FTF amplitude response of the flame. Then, an industrial gas turbine is analyzed for two different burner geometries and operating conditions. The FTF is only slightly influenced for the two operating points but slight modifications of the swirler geometry do modify the characteristics of the FTF showing that a simple model taking only into account the flight time is not appropriate and additional mechanisms are at play. Those mechanisms are identified being the inlet velocity, the swirl and the inlet mixture fraction fluctuations. The latter is caused by two mechanisms: 1) the pulsating injected fuel flow rate and 2) the fluctuating trajectory of the fuel jets. Although the diagonal swirler is designed to provide good mixing, effects of mixing heterogeneities at the combustion chamber inlet occur. Mixture perturbations phase with velocity (and hence with swirl) fluctuations and combine with them to lead to different FTF results. Another FTF approach linking heat release to inlet velocity and mixture fraction fluctuation (MISO model) shows further to be a good solution for complex systems. A nonlinear analysis shows that the forcing amplitude not only leads to a saturation of the flame but also to changes of the delay response. Flame saturation is only true for the global FTF and the gain increases locally with increasing forcing amplitude. Both, the linear and the nonlinear flames, are not compact: flame regions located right next to each other exhibited significant differences in delay meaning that at the same instant certain parts of the flame damp the excitation while others feed it.

Approved for public release, distribution is unlimited / In this study, the use of multi narrow-band filters was explored to correlate or fuse information to improve detection and recognition for specific targets of interest. To fully understand the viability and limitations of narrow band filters in thermal imaging, laboratory test procedures were first designed to characterize thermal images using common performance parameters, particularly the Noise Equivalent Temperature Difference (NETD), the Modulation Transfer Function (MTF) and the Minimum Resolvable Temperature (MRT). An available thermal imager, the Cincinnati Electronics IRRIS-256LN, and a newly purchased thermal imager, the Indigo Systems Merlin InSb Laboratory Camera, were investigated and compared. The MRT measurement showed a superior cut-off spatial frequency of 1.33 cycle/mrad for the Merlin camera, compared with 1.18 cycle/mrad for the Cincinnati, with similar sensitivity of about 0.1 ʻC for both cameras. Below cut-off the Modulation Transfer for the Merlin was approximately twice that of the Cincinnati. NETD measurements for both systems were inhibited by excess noise in the measurement system. The Merlin camera was consequently employed for further research on narrow band images. Three commercially available narrow band filters, 4110/4720 nm, 4540/4720 nm and 3750/4020 nm, were selected to isolate the "red" and "blue" spike signatures of plume emission and aerodynamic heating found in the signature of fast moving air targets. Similar sensor characterization was carried out with these filters, however, quantitative performance parameter measurements were hindered by excessive measurement system noise. As a preliminary study in multi-spectral image analysis, spectral features of hydrocarbon combustion were extracted from correlated narrow-band images of a laboratory propane flame. Digital analysis using software statistical tools showed potential for discrimination of hydrocarbon emission from other thermal sources by correlating pixel number and pixel radiant intensity. / Captain, Singapore Armed Forces

Este trabalho apresenta diversas propostas associadas ao uso ótimo de funções de transferência relativas à cabeça (HRTFs) em sistemas de reprodução acústica virtual por fones de ouvido. Estas propostas permitem personalizar a HRTF a indivíduos particulares, tomando como base uma combinação da modelagem estrutural e morfológica de HRTFs. Dentro do contexto da modelagem estrutural, o presente trabalho se concentrou no estudo da contribuição do pinna à HRTF. O pinna é a estrutura anatômica responsável pela percepção de elevação. Assim, o primeiro passo foi extrair um conjunto de funções de transferência relativas ao pinna (PRTFs) das HRTFs de uma base de dados. Para tanto, foram usadas diversas técnicas como análise preditiva linear para rastrear as ressonâncias, janelamento para eliminar a influência do torso, funções de autocorrelação e de atraso de grupo para salientar as antirressonâncias, e outros algoritmos para combinar ressonâncias e antirressonâncias em apenas uma magnitude espectral. Usando essa nova base de dados de PRTFs e parâmetros antropométricos propostos mais outros registrados na base de dados, um espaço vetorial correspondente à antropometria do pinna foi mapeado linearmente em um espaço vetorial correspondente às características espectrais da PRTF, calculando-se assim várias transformações lineares para estimação de novas PRTFs fora da base de dados. A estimação atingiu 66% de reconstrução no grupo de treino. O trabalho está orientado à exploração das características espectrais importantes na percepção de elevação, portanto, está limitado ao plano médio do hemisfério frontal, onde não existem diferenças interaurais significativas nem efeitos difrativos da cabeça. Finalmente é proposto um sistema de testes de localização de fonte sonora para validar o modelo. / This work presents several proposals associated with the optimal use of head-related transfer functions (HRTF) in virtual auditory spaces presented via headphones. These proposals lead to personalization of the HRTF to particular individuals, using a combination of the structural and morphological modeling techniques. In the context of structural modeling, this work focuses on modeling the contribution of the pinna to the HRTF. The pinna is the anatomical structure responsible for vertical sound localization. Thus, the first step was to extract a set of pinna-related transfer functions (PRTFs) from HRTFs published in a database. This was accomplished using several techniques like linear prediction analysis for tracking the resonances, windowing for eliminating the torso influence, autocorrelation and group delay functions for emphasizing the notches and other algorithms for combining resonances and notches in only one magnitude response. Using this novel database of PRTFs and a set of proposed anthropometric parameters plus some others registered in the database, a vector space corresponding to pinna anthropometry is linearly mapped into a vector space corresponding to spectral features of the PRTF, being calculated, in this way, several linear transformations for estimation of new PRTFs, outside the database. The estimation attains 66% of reconstruction in the training group. The work focuses on the exploration of spectral characteristics important for elevation perception, therefore, it is limited to the median plane where there are no meaningful interaural differences nor head diffraction effects. Finally, a system for sound localization tests is proposed in order to validate the model.

Made available in DSpace on 2016-07-27T14:20:52Z (GMT). No. of bitstreams: 1 Lucas Delfino Araujo.pdf: 602785 bytes, checksum: 69699e38b827976292d3cd40cebe4b0e (MD5) Previous issue date: 2015-03-13 / The aim of this study was to evaluate the effect of different procedures on the transfer function between perceptual and verbal stimuli. Three experiments were conducted with 10 participants each, of both sex and university. In Experiment 1 was performed a conditional discrimination procedure using Matching-to-Smple having a stimulus as a model and three as a comparison. A set A was composed of three perceptual stimuli (pictures), a joint B consisted of three words without meaning and set C consisted of three words with meaning. Training was made between set B and set C then set A to set B (Group 1) and inverse training (group 2). The Experiment 2 was similar to Experiment 1, but comparisons were made gradually over the first comparison blocks to complete 3 comparisons and all followed the Group s training sequence 1 Experiment 1. In Experiment 3 was made a training with presentation of stimuli verbal (sentences) and a conditional discrimination training between meaningless words and words with meaning. Data from the three procedures indicate that there is transfer function between words with meaning, figures and meaningless words, and 40% of the participants in Experiment 1 were obtained transfer function for the three meaningless words, 80% of the participant in Experiment 2 achieved transfer function for the three meaningless words and 100% of the participants in Experiment 3 obtained transfer function for the three meaningless words. / O objetivo do presente trabalho foi verificar o efeito de diferentes procedimentos sobre a transferência de função entre estímulos perceptuais e verbais. Foram realizados três experimentos contendo 10 participantes cada, de ambos os sexos e universitários. No Experimento 1 foi realizado um procedimento de discriminação condicional utilizando Matching-to-Smple tendo um estímulo como modelo e três como comparação. Um conjunto A compunha-se de três estímulos perceptuais (figuras), um Conjunto B compunha-se de três palavras sem sentido e um Conjunto C compunha-se de três palavras com sentido. Foi feito treino entre Conjunto B e Conjunto C e depois de Conjunto A com Conjunto B (Grupo 1) e treino inverso (Grupo 2). No Experimento 2 foi semelhante ao Experimento 1, mas as comparações eram apresentadas gradualmente durante os blocos de 1 comparação até completar 3 comparações e todos seguiram a sequência de treino do Grupo 1 do Experimento 1. No Experimento 3 foi feito um treino com apresentação de estímulos verbais (sentenças) e um treino de discriminação condicional entre palavras sem sentido e palavras com sentido. Os dados dos três procedimentos indicam que há transferência de função entre palavras com sentido, figuras e palavras sem sentido, sendo que 40% dos participantes do Experimento 1 obtiveram transferência função para as três palavras sem sentido, 80% dos participantes do Experimento 2 obtiveram transferência de função para as três palavras sem sentido e 100% dos participantes do Experimento 3 obtiveram transferência de função para as três palavras sem sentido.

Made available in DSpace on 2016-08-10T10:40:36Z (GMT). No. of bitstreams: 1 MARINA MEIRELES PEREIRA.pdf: 5021994 bytes, checksum: 7b9170817bc15d6c6c8810e83ac1330e (MD5) Previous issue date: 2016-02-15 / This research aims to apply a prediction model to a tire closed-loop supply chain to estimate the volume returned of scrap tires, through the variables that influence the amount and time that these tires are returned to destination. The methodological approach applied in this research is the modeling by applying the Transfer Function Model. It starts with the analysis that the tire closed-loop supply chain of Goiás and the Federal District is structured and there is a direct relationship between sales of tires with the amount returned. Were adopted as model input variables the amount of tires placed on the market for after-market and the size of the current fleet of these places, representing the amount of tires entered the market for new cars sold. For the output variable was considered the quantity of scrap tires collected and sent for disposal. The data for the survey were collected in the organization s databases adopted as an object of study, IBAMA, DENATRAN, ANIP and AliceWeb considering a period of 54 months. Data were analyzed by the transfer function model and the results showed that the lag time after the tires were entered on the market was around 12 months for all input variables, the return probability of the after-market are greater than the return probability of the tire fleets, and the behavior of the predicted return showed an approximate behavior of the real return with a percentage deviation of 3.4%. Therefore, this study enabled us to identify the variables that influence the return of scrap tires and scale the amount of returned volume tires and the time of this return to facilitate the planning of the tires of closed-loop supply chain. / Esta pesquisa visa aplicar um modelo de previsão a uma cadeia de suprimentos de ciclo fechado de pneus, para estimar o volume de pneus inservíveis retornados, por meio das variáveis que influenciam na quantidade e no tempo que estes pneus retornam para serem destinados. A abordagem metodológica aplicada nessa pesquisa se situa na Modelagem, aplicando o Modelo de Função de Transferência. Parte-se da análise de que a cadeia de suprimentos de ciclo fechado do Estado de Goiás e Distrito Federal está estruturada e que há uma relação direta entre as vendas de pneus com a quantidade retornada. Foram adotadas como variáveis de entrada do modelo a quantidade de pneus inseridos no mercado, pelo mercado de reposição e o tamanho da frota circulante destas localidades, representando a quantidade de pneus inseridos no mercado pelos carros novos vendidos. Para a variável de saída foi considerada a quantidade de pneus inservíveis coletados e encaminhados para destinação final. Os dados utilizados na pesquisa foram coletados em bancos de dados da organização adotada como objeto de estudo, IBAMA, DENATRAN, ANIP e AliceWeb, considerando de um período de 54 meses. Os dados foram analisados pelo modelo de função de transferência e os resultados obtidos mostraram que o tempo de defasagem da entrada de pneus no mercado foi em torno de 12 meses para todas as variáveis de entrada, que as probabilidades de retorno do mercado de reposição são maiores que as probabilidades de retorno dos pneus das frotas e que a previsão de retorno apresentou um comportamento aproximado do comportamento real do retorno com um desvio percentual de 3,4%. Portanto, este estudo possibilitou identificar as variáveis que influenciam no retorno de pneus inservíveis e a dimensionar a quantidade de volume de pneus retornados e o tempo desse retorno para viabilizar o planejamento da cadeia de suprimentos de ciclo fechado de pneus.