Made available in DSpace on 2015-03-26T13:50:18Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4867589 bytes, checksum: dbb424a056c781a7ce72f8bd99836245 (MD5) Previous issue date: 2007-02-09 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Annual rainfalls data, provived by the Agência Nacional das Águas (ANA), were analyzed with objective of identifying climatically homogeneous data series using the statistical technique of "cumulative residues", starting from data of 78 meteorological stations network of the State of Minas Gerais. For all the climatically homogeneous areas, a reference station was chosen, and later, each reference station data series were analyzed against other rainfall stations within the same homogeneous climatic area. For all over the areas, it was chosen a reference station with the largest number of complete data series, and later, each reference data series was analyzed against the other data series of rainfall stations belonging to the same climatic area. Starting from the identification of statistically homogeneous rainfall data series, an attempt of reconstruction of the series was carried out, by filling of missing values. The "cumulative residues" technique was shown to be very efficient, even when the number of stations used for some climatically homogeneous areas was a limiting factor. After the data series reconstructions, for each station the inverse of the square of the distance method of interpolation (IDW) and the method of ordinary krigging (KG) were used, to analyze the annual precipitation in space for every year between 1942 and 2000. For the krigging algorithm, semi-variograms were adjusted, to verify the degree of space dependence (IDE), by means of spherical model. The IDE mean values found for all analyzed years were about 30.3%, which represent moderate space dependence. Both methods of interpolations employed were also evaluated based on cross validation test, in which it did supply the values of mean error (Em) and the coefficient of variation (ρf). The mean error average found in between 8.198 for the IDW method and 0.457 for the krigging. The coefficients of variation presented varied from 0.121 to 0.372 for IDW and 0.112 to 0.352 for krigging. The results showed that the geostatistic method of ordinary krigging was more efficient than the IDW method with the smallest mean errors (Em) and coefficients of variation (ρf). / Os dados anuais de precipitação, fornecidos pela Agência Nacional de Águas (ANA), foram analisados com o objetivo de identificar séries climatológicas homogêneas, por meio de técnicas estatísticas de resíduos cumulativos a partir dos dados de uma rede de 78 estações meteorológicas do Estado de Minas Gerais. Utilizaram-se os resultados apresentados por Aspiazu et al. (1990), que delimitaram 10 regiões climaticamente homogêneas no Estado de Minas Gerais, para a análise de homogeneidade. Para todas as regiões foi escolhida uma estação de referência, e, posteriormente, cada série de referência foi analisada com as outras estações pertencentes à mesma região climática. As estações de referência escolhidas foram as que apresentaram maior número de dados completos dentro de cada região. A partir da identificação de séries homogêneas, foi feita a reconstrução das séries climatológicas, fazendo-se o preenchimento de falhas com dados faltantes. A técnica de resíduos cumulativos empregada mostrou-se eficiente, mesmo o número de estações utilizadas para algumas regiões climaticamente homogêneas ter sido um fator limitante. Depois do preenchimento de falhas, empregou-se o método de interpolação inverso do quadrado da distância (IDW), bem como o método de krigagem ordinária (KG), para posteriormente promover a espacialização da precipitação anual para cada ano entre 1942 e 2000. Com o método de krigagem, foram ajustados semivariogramas, para verificar o grau de dependência espacial (IDE), havendo predominância do modelo esférico. O valor médio do IDE encontrado para todos os anos analisados foi de 30,3%, que representa moderada dependência espacial. Ambos os métodos de interpolação empregados foram avaliados com base no teste de validação cruzada, que forneceu os valores de erro médio (Em) e o coeficiente de variação (ρf). A média do erro médio encontrada foi de 8,198 com o método IDW e 0,457 com o método de krigagem. Os coeficientes de variação variaram de 0,121 a 0,372 para IDW e 0,112 a 0,352 para krigagem. Os resultados evidenciaram que o método geoestatístico de krigagem ordinária se mostrou mais eficiente do que o método de IDW, tendo em vista os menores erros médios.

The scientific development has the aim of executing experiments with such quality so that obtained results are accepted and recommended. The quality of an experiment can be described through statistics, ascribing it reliance on the obtained data, being the experimental error one of the parameters the evaluations of such quality. Therefore, the present work aimed at verifying the interference of different positions of seedlings on polystyrene trays on the normality and homogeneity of the errors in experiments carried out in different environments of lettuce production. Six experiments were carried out in the Departamento de Fitotecnia da Universidade Federal de Santa Maria in the summer (2006-2007) and fall winter (2007) with the lettuce crop, cultivar Vera two with seedling production in a greenhouse and four with the production of plants, two in a plastic structure and two in the field, the treatments were defined by 12 different positions of the seedlings on the tray of production. The analyzed variables in the seedling production and after their transplant to the environments were the fresh and dry phytomass of leaves and roots (g) and the fresh and dry phytomass of leaves (g), respectively. Presuppositions of errors normality and homogeneity were tested being compared to the averages of each treatment, as well as the conjoint analysis of the experiments. The different positions of the lettuce seedlings on the production trays did not significantly interfere in the experimental error estimative in the carried out experiments in plastic greenhouse and in the field. The central positions of seedlings was contributive in the final media of the lecttuce plants in greenhouse and in the field. In the summer experiments, the recommendations should be carried out individually to each environment, while in the fall winter experiments they can be generalized to both production environments. / O desenvolvimento da ciência é atingido pela execução de experimentos com qualidade, para que os resultados gerados sejam aceitos e recomendados. A qualidade de um experimento pode ser descrita através de estatísticas, sendo o erro experimental um dos parâmetros de avaliação dessa qualidade. Assim, o objetivo desse trabalho foi verificar a interferência de diferentes posições de mudas em bandeja de poliestireno sobre a normalidade e homogeneidade dos erros em experimentos realizados em dois ambientes de produção de alface. Foram conduzidos seis experimentos no Departamento de Fitotecnia da Universidade Federal de Santa Maria nas estações verão (2006-2007) e outono-inverno (2007) com a cultura da alface, cultivar Vera, dois com produção de mudas em casa de vegetação e quatro com produção de plantas, sendo dois em estufa plástica e dois a campo. Os tratamentos foram 12 diferentes posições das mudas na bandeja de produção. As variáveis analisadas na produção de mudas e após o transplante aos ambientes foram a fitomassa fresca e seca da parte aérea e raiz (g) e fitomassa fresca e seca da parte aérea (g), respectivamente. Foram testadas as pressuposições da homogeneidade dos tratamentos e normalidade dos erros sendo comparadas as médias de cada tratamento, bem como realizada a análise conjunta dos experimentos. Não houve violação das pressuposições de homogeneidade das variâncias dos tratamentos e normalidade dos erros nos experimentos com diferentes posições de mudas na bandeja de produção, nos diferentes ambientes e épocas de cultivo para a cultura do alface. As diferentes posições das mudas de alface nas bandejas de produção não interferiram na estimativa do erro experimental nos experimentos conduzidos em estufa plástica e em campo. As posições centrais das mudas das repetições contribuíram na produtividade final das plantas de alface em estufa plástica e em campo. Em experimentos com a cultura da alface conduzidos no verão, as recomendações das diferentes posições das plântulas para o cultivo devem ser realizadas individualmente em estufa e em campo, enquanto que no outono-inverno as mesmas podem ser generalizadas para os dois ambientes de produção.

The currently reported thesis was concerned with visualisation of the charge homogeneity and cyclic variations within the planar fuel field near the spark plug in an optical spark ignition engine fitted with an outwardly opening central direct fuel injector. Specifically, the project examined the effects of fuel type and injection settings, with the overall view to understanding some of the key mechanisms previously identified as leading to particulate formation in such engines. The three fuels studied included a baseline iso-octane, which was directly compared to two gasoline fuels containing 10% (E10) and 85% (E85) volume of ethanol respectively. The engine was a bespoke single cylinder with Bowditch style optical access through a flat piston crown. Charge stratification was studied over a wide spectrum of injection timings using the Planar Laser Induced Fluorescence (PLIF) technique, with additional variation in charge temperature due to injection also estimated when viable using a two-line PLIF approach. Overall, both gasoline-ethanol fuels generally exhibited a higher degree of stratification, albeit at least partly alleviated with elevated rail pressures. Under both warm and cold liner conditions the E10 fuel showed clear evidence of fuel droplets persisting up until ignition. Interestingly, with late injection timing the repeatability of the injection was superior (statistically) with higher ethanol content in the fuel, which may have been associated with the higher charge temperatures aiding control of the evaporation of the main mass of alcohol. The findings were corroborated by undertaking a comprehensive study of the influence of varying fuel type and injection settings on thermodynamic performance and engine-out emissions during firing operation, with additional gas exchange effects also influencing the optimum fuel injection timings.

Experimentos sistemáticos de crescimento de cristais pelo método de soluções sólidas óxidas de GdAlO3:Cr3+ (estrutura pseudo perovskita), foram efetuados em diversas composições de solventes. Os perfis de concentrações dopante (Cr3+) e do solvente (Pb),em amostras previamente selecionadas e os coeficientes de segregação efetivos foram determinados e comparados com os dos cristais crescidos pelo método Czochralski. Modelos teóricos foram desenvolvidos para o entendimento dos resultados experimentais e outros são propostos com o objetivo de fornecer tratamentos alternativos para os efeitos dos parâmetros de crescimento tais como: flutuações térmicas, forma geométrica nucleações secundárias, evaporação do dopante, reações químicas e estabilidade de crescimento na homogeneidade das soluções sólidas. Devido ao interesse científico-tecnológico também foram crescidos outros cristais de estrutura perovskita como GdAlO3:La3+, LaAlO3:Cr3+ e NdAlO3:La3+ pelo método de fluxo e GdAlO3:Cr3+:La3+, pelo método Czocharalski e os resultados das experiências de crescimento estão descritas neste trabalho. / Systematic growth experiments by flux method of the oxides solid solutions of GdAlO3:Cr3+ (perovskite type) were done with several solvents compositions. The doping (Cr3+) and solvent (Pb) concentrations profiles in selected samples, and the effetive segregations coefficient were determined and compared with those obtained by Czochralski method. Theoretical models for crystal growth process were developed to understand the experimental results, and others are proposed to give alternative treatment on several growing parameters like thermal fluctuations, geometric crystal shape, secondary nucleations, doping evaporations, chemical reactions and growth stability effects in the solid solutions homogeneity. Due to scientific and technological interest, also were grown other perovskite crystals like GdAlO3:La3+, LaAlO3:Cr3+ and NdAlO3:La3+ by flux method and GdAlO3:Cr3+:La3+ by Czochralski method and the results are descrived in the present work.

Background: Automobile lighting is a major function on any automobile to illuminate the road to let drivers and commuters see the road ahead. It also serves a variety of other purposes. However, it is now becoming a luxury design feature, with each automobile manufacturer having their own unique lamps. Every car manufacturer now has its own characteristic lights that can be recognized from a considerable distance, and they strive for homogeneity. As a result, it’s critical to check and assess a lamp's homogeneity during the product development phase to identify any potential flaws. Objectives: This research presents a HDRImage encoding for visualizing and verifying luminance data in image format. For an intuitive and subjective evaluation also the colour is used. Secondly, using the mean filter technique to validate an internal Volvo Cars lit surface homogeneity requirement and automate the time-consuming process. Lastly, using the ISOcontour approach to propose and implement a simple yet effective verification method for distributed light homogeneity. Methods: The research methods used in this study are literature review and experiment. To discover further about HDRImage encoding using luminance data, as well as existing light measurement and evaluation approaches, a literature review is conducted. The appropriate approaches for this study are then combined and implemented to produce a verification method that uses the homogeneity requirement to automatically verify lit surfaces. This thesis also presented ISOcontour lines as a way for evaluating distributed light. Results: The findings of this thesis demonstrate that it is possible to develop a method for verifying and evaluating luminance data obtained from simulation software and photometers without relying on any licensed software for light evaluation. The methods are, for visualisation using HDRImage encoding, a method to evaluate light such as false colour, ISOcontour lines for distributed light verification, and an automatic homogeneity verification approach for lit surface to make the verification of illumination process efficient. Conclusions:  Experiment provided a means of visualizing luminance data of both virtual and physical prototypes, verifying distributed light, and automatically verifying it surface homogeneity, while literature review assisted in gathering information in certain fields to better comprehend light evaluation methods.

This thesis deals with study homogeneity of thin organic layers using image analysis. The theoretical parts deal with preparation thin layers and some methods examining their surface, especially optical microscopy and profilometry. Optical microscope NIKON ECLIPSE E200, digital camera NIKON 5400 and computer was used for study homogeneity of organic layers by image analysis. Images of the organic layer and single electrodes, which were steamed on organic layer, were surveyed. Homogeneity of surfaces layers was assessed by errors related with common moments (roughness average, root mean square roughness, skewness, and kurtosis). Differences between single samples in connection with size their common moments and homogeneity are discussed at the close of this work.

The selection of a representative sample is a delicate problem when drug seizures comprised of large number of units arrive at the Swedish National Forensic Centre (NFC). If deviating objects in the selected sample size are found, additional analyzes are required to investigate how representative the results are for the entire population. This generates further pressure on operational analysis flow. With the goal to provide a tool which forensic scientists at NFC can base their assessment of the representative nature of the selected sampling of large drug seizures on, this project investigated the possibilities of evaluating the level of homogeneity in drug seizures using near-infrared (NIR) hyperspectral imaging along with principal component analysis (PCA). A total of 27 sample groups (homogeneous, heterogeneous and seized sample groups) were analyzed and different predictive models were developed. The models were either based on quantifying the variation in NIR spectra or in PCA scores plots. It was shown that in the spectral range of 1300-2000 nm, using a pre-processing combination of area normalization, quadratic (second polynomial) detrending and mean centering, promising predictive abilities of the models in their evaluation of the level of homogeneity in drug seizures were achieved. A model where the approximated signal-dependent variation was related to the quotient of significant and noise explained variance given by PCA indicated most promising predictive abilities when quantifying the variation in NIR spectra. Similarly, a model where a rectangular area, defined by the maximum distances along PC1 and PC2, was related to the cumulative explained variance of the two PCs showed most promising predictive abilities when quantifying the variation in PCA scores plots. Different zones for which within sample groups are expected to appear based upon their degree of homogeneity could be established for both models. The two models differed in sensitivity. However, more comprehensive studies are required to evaluate the models applicability from an operational point-of-view.

Using DiVAs data on published works and their authors, a database was constructed on which Girvan-Newmans (2002) and Rosvall-Bergstroms (2007) community finding algorithms were applied. The results were compared in an effort to evaluate the current allocation of researchers at KTH's divisions and the performance of said algorithms on the collaboration network. Rosvall-Bergstrom performed better than Girvan-Newman both in result and performance. The results of both algorithms are similar, and illustrate that the current allocation of researchers forces work across school borders. / Med DiVAs data om publicerade verk och deras författare, skapades en databas som Girvan-Newmans (2002) and Rosvall-Berstroms (2007) grupperingsdetektionsalgoritmer applicerades på. Resultaten jämfördes med som mål att utvärdera den nuvarande placeringen av forskare vid KTHs interna skolor och algoritmernas prestanda på samarbetsnätverket. Rosvall-Bergstroms presterade bättre än Girvan-Newmans både i resultat och i prestanda. Resultatet av båda algoritmerna är lika, och visar att den nuvarande placeringen av forskare tvingar till samarbete över skolornas gränser.

We analyze the replica-symmetry-breaking (RSB) construction in the Sherrington - Kirkpatrick (SK) model and in the p-state Potts glass for p ≤ 4. We present a general scheme for deriving an asymptotic solution with an arbitrary number of discrete hierarchies of broken replica symmetry near the critical temperature for both models, and close to the de Almeida- Thouless instability line in the SK model. We show that in the SK model all solutions with finite many hierarchies are unstable and only the scheme with infinite many hierarchies becomes marginally stable in the spin-glass phase. For the Potts glass, we find, moreover, an one-step RSB solution which co- exists with the infinite RSB solution for p > p∗ ≈ 2.82. The former solution is locally stable but has lower free energy than the latter which is marginally stable and has the highest free energy. 1

Práce je věnována generování náhodných struktur dvousložkových vláknových kompozitních materiálů a statistickým metodám analýzy náhodnosti těchto struktur. Byly vyvinuty čtyři algoritmy a vygenerované struktury byly statisticky porovnány s reálnými daty.