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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Titulador automático baseado em filmes digitais para determinação de dureza e alcalinidade total em águas minerais/Titulador automático baseado em filmes digitais para determinação de dureza e alcalinidade total em águas minerais

Siqueira, Lucas Alfredo 29 February 2016 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2017-06-21T14:26:33Z No. of bitstreams: 1 arquivototal.pdf: 3690977 bytes, checksum: 752560aa5c7d78968c32cb55f0778788 (MD5) / Made available in DSpace on 2017-06-21T14:26:33Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3690977 bytes, checksum: 752560aa5c7d78968c32cb55f0778788 (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Total hardness and Total alkalinity are important physico-chemical parameters for the evaluation of water quality and are determined by volumetric analytical methods. These methods have difficult to detect the endpoint of the titration due to the difficult of viewing the color transition inherent to each of them. To circumvent this problem, here is proposed a new automatic method for the detection of the titration end point for the determination of total hardness and total alkalinity in mineral water samples. The proposed flow-batch titrator consists of a peristaltic pump, five three-way solenoid valves, a magnetic stirrer, an electronic actuator, an Arduino MEGA 2560TM board, a mixing chamber and a webcam. The webcam records the digital movie (DM) during the addition of the titrant towards mixing chamber, also recording the color variations resulting from chemical reactions between titrant and sample within chamber. While the DM is recorded, it is decompiled into frames ordered sequentially at a constant rate of 30 frames per second (FPS). The first frame is used as a reference to define the region of interest (RI) of 48 × 50 pixels and the R channel values, which are used to calculate the Pearson's correlation coefficient (r) values. r is calculated between the R values of the initial frame and each subsequent frame. The titration curves are plotted in real time using the values of r (ordinate axis) and the total opening time of the valve titrant (abscissa axis). The end point is estimated by the second derivative method. A software written in ActionScript 3.0 language manages all analytical steps and data treatment in real time. The feasibility of the method was attested by its application for the analysis of natural water samples. Results were compared with classical titration and did not present statistically significant differences when the paired ttest at the 95% confidence level was applied. The proposed method is able to process about 71 samples per hour, and its precision was confirmed by overall relative standard deviation (RSD) values, always lower than the 2,4% for total hardness and 1,4% for total alkalinity. / A dureza total e a alcalinidade total são importantes parâmetros físico-químicos para avaliação da qualidade de águas e são determinados por métodos volumétricos de análise. Estes métodos apresentam difícil detecção do ponto final da titulação devido à dificuldade de visualização das transições de cores inerentes a cada um deles. Para contornar este problema, foi proposta neste trabalho uma nova metodologia automática para a detecção do ponto final nas determinações de dureza total e alcalinidade total em águas. O titulador em fluxo-batelada proposto é composto de uma bomba peristáltica, cinco válvulas solenoides de três vias, um agitador magnético, um acionador de válvulas, uma placa Arduíno MEGA 2560TM, uma câmara de mistura e uma webcam. O programa de gerenciamento e controle do titulador foi escrito em linguagem ActionScript 3.0. A webcam grava o filme digital durante a adição do titulante na câmara de mistura, registrando as variações de cor decorrentes das reações químicas entre titulante e amostra no interior de câmara. Enquanto o filme é gravado, este é decomposto em quadros ordenados sequencialmente a uma taxa constante de 30 quadros por segundo (FPS). O primeiro quadro é utilizado como referência para definir uma região de interesse (RI) com 48 x 50 pixels, na qual seus valores R, G e B são utilizados para calcular os valores de coeficiente de correlação de Pearson (r). O valor de r é calculado entre os valores de R do quadro inicial e de cada quadro subsequente. As curvas de titulação são obtidas em tempo real usando os valores de r (ordenadas) e o tempo total de abertura da válvula de titulante (abscissas). O ponto final é estimado pelo método de segunda derivada. O método foi aplicado na análise de águas minerais e os resultados foram comparados com a titulação clássica, não apresentando diferenças estatisticamente significativas com aplicação do teste t pareado a 95% de confiança. O método proposto foi capaz de processar até 71 amostras por hora e a sua precisão foi confirmada pelos valores de desvio padrão relativos (DPR) globais, sempre inferiores as 2,4% para dureza total e 1,4% para alcalinidade total.
22

Parciální a podmíněné korelační koeficienty / Partial correlation coefficients and theirs extension

Říha, Samuel January 2015 (has links)
No description available.
23

Grandes déviations précises pour des statistiques de test / Sharp Large Deviations for some Test Statistics

Truong, Thi Kim Tien 10 December 2018 (has links)
Cette thèse concerne l’étude de grandes déviations précises pour deux statistiques de test:le coefficient de corrélation empirique de Pearson et la statistique de Moran.Les deux premiers chapitres sont consacrés à des rappels sur les grandes déviations précises et sur la méthode de Laplace qui seront utilisés par la suite. Par la suite, nous étudions les grandes déviations précises pour des coefficients de Pearson empiriques qui sont définis par:$r_n=\sum_{i=1}^n(X_i-\bar X_n)(Y_i-\bar Y_n)/\sqrt{\sum_{i=1}(X_i-\bar X_n)^2 \sum_{i=1}(Y_i-\bar Y_n)^2}$ ou, quand les espérances sont connues, $\tilde r_n=\sum_{i=1}^n(X_i-\mathbb E(X))(Y_i-\mathbb E(Y))/\sqrt{\sum_{i=1}(X_i-\mathbb E(X))^2 \sum_{i=1}(Y_i-\mathbb E(Y))^2} \, .$. Notre cadre est celui d’échantillons (Xi, Yi) ayant une distribution sphérique ou une distribution gaussienne. Dans chaque cas, le schéma de preuve suit celui de Bercu et al.Par la suite, nous considérons la statistique de Moran $T_n=\frac{1}{n}\sum_{k=1}^n\log\frac{X_i}{\bar X_n}+\gamma \, ,$o\`u $\gamma$, où γ est la constante d’ Euler. Enfin l’appendice est consacré aux preuves de résultats techniques. / This thesis focuses on the study of Sharp large deviations (SLD) for two test statistics:the Pearson’s empirical correlation coefficient and the Moran statistic.The two first chapters aim to recall general results on SLD principles and Laplace’s methodsused in the sequel. Then we study the SLD of empirical Pearson coefficients, name $r_n=\sum_{i=1}^n(X_i-\bar X_n)(Y_i-\bar Y_n)/\sqrt{\sum_{i=1}(X_i-\bar X_n)^2 \sum_{i=1}(Y_i-\bar Y_n)^2}$ and when the meansare known,$\tilde r_n=\sum_{i=1}^n(X_i-\mathbb E(X))(Y_i-\mathbb E(Y))/\sqrt{\sum_{i=1}(X_i-\mathbb E(X))^2 \sum_{i=1}(Y_i-\mathbb E(Y))^2} \, .$ .Our framework takes place in two cases of random sample (Xi, Yi): spherical distributionand Gaussian distribution. In each case, we follow the scheme of Bercu et al. Next, westate SLD for the Moran statistic $T_n=\frac{1}{n}\sum_{k=1}^n\log\frac{X_i}{\bar X_n}+\gamma \, ,$o\`u $\gamma$ , where γ is the Euler constant.Finally the appendix is devoted to some technical results.
24

En jämförelse av den riskjusterade avkastningen mellan aktiemarknaden och bostadsrättsinvesteringar.

Kroon, Theo, Rolfmark, Rasmus January 2023 (has links)
This is a study where the purpose is to investigate the risk-adjusted return and the correlation between the two investments, the stock market and the condominium market. In addition to this, it was analyzed how the two investments performed during the financial crisis and the covid-19 crisis. Study is carried out to get answers to the eternal question of which of these two investments is considered the most suitable for both short-term or long-term investment goals where financial conditions are taken into account. The study conducted various tests such as Pearson correlation test, volatility and regression models. The Sharpe ratio was used to measure the risk-adjusted return. These are carefully selected to see what returns the two investments give at different risks, as well as how the investments correlate with each other during crises and conditions of economic growth. The conclusion reached by this study is that the investor should diversify and invest in both investments. This is because their risk versus return profile becomes more even by investing in both investments. When one investment does worse, the other investment will, according to the study's various tests, make the return and risk profile more stable. Despite the high correlation between the investments, diversification is useful in case of possible future economic crises. / Detta är en studie där syftet är att undersöka den riskjusterade avkastningen samt korrelationen  mellan de två investeringarna aktiemarknaden och bostadsrättsmarknaden. Utöver detta analyserades hur de två investeringarna presterade under finanskrisen och covid-19-krisen.  Studie är genomförd för att få svar på den eviga frågan om vilken av dessa två investeringar som anses vara lämpligast för både kortsiktiga eller långsiktiga investeringsmål där ekonomiska förhållanden tas i akt.  Studien genomförde olika tester som Pearson korrelationstest, volatilitet och regressionsmodeller. Sharpekvoten användes  för att mäta den riskjusterade avkastningen. Dessa är noga utvalda för att se vad de två investeringarna ger för avkastning vid olika risker, samt hur investeringarna korrelerar med varandra under kriser och förhållanden vid ekonomisk tillväxt. Slutsatsen som denna studie kom fram till är att investeraren bör diversifiera sig och investera i båda investeringarna. Detta på grund av att deras riskprofil kontra avkastning blir mer jämnare genom att investera i båda investeringarna. När den ena investeringen går sämre kommer den andra investeringen som enligt studiens olika tester att göra att avkastningen och riskprofilen blir mer stabil. Trots den höga korrelationen mellan investeringarna så är diversifiering användbar vid eventuella framtida ekonomiska kriser.
25

Comparative analysis of the relationship between the producer and consumer price index of beef and chicken meat in South Africa from 1991to 2018

Aphane, Thabang Rasehla January 2022 (has links)
Thesis (M.Sc. Agriculture (Agricultural Economics)) -- University of Limpopo, 2022 / Beef and chicken meat play a very crucial role in providing food to South African consumers. However, the rise of food prices in South Africa is viewed to curtail progress and drives consumers into debt and forgone opportunity to access food. Hence, it is of importance to understand the consumer price index (CPI) of meat and the disaggregate components of beef and chicken meat producer price indexes (PPI) as they give a clear insight into how individual commodities contribute to the general and food price inflation. The study aimed to comparatively analyse the relationship between PPI beef and CPI meat as well as PPI chicken meat and CPI meat in South Africa from 1991 to 2018. The objectives of the study were to compare the indexes’ variability, correlation, and causality between the different PPI and CPI components. The objectives were analysed using the Coefficient of variation (CV), the Pearson coefficient correlation, the Granger causality test, and the Vector Error Correction model. The CV findings highlight that PPI beef had high variability (65%) compared to CPI meat (56.7%), whereas PPI chicken meat had low variability (49.2%) compared to CPI meat(56.7%). There was evidence of a positive correlation (0.99) between PPI beef and CPI meat as well as PPI chicken meat and CPI meat using Pearson coefficient correlation. In addition, a long-run relationship was found between PPI beef and CPI meat as well as between PPI chicken meat and CPI meat by using the VEC model. Granger causality results indicated that there was a unidirectional relationship from PPI chicken meat to CPI meat, and independent relationships were found from PPI beef to CPI meat, CPI meat to PPI beef as well as CPI meat to PPI chicken meat. Based on the findings, the study recommends that policymakers, through evaluation of monetary policies, should continue maintaining a specific inflation target range as that will assist in stabilising meat prices in the economy. At the same time, protect meat producers against input price inflation using instruments such as input subsidies, grants, and the provision of modern technologies. / National Research Foundation (NRF)
26

Analysis of Suspended Sediment Loads in Streams and Rivers using Linear Regression and Pearson Correlation

Sakwe, Chantal Wase January 2015 (has links)
No description available.
27

Vliv vybraných kondičních faktorů na výkonnost ve vodním slalomu / Influence of selected conditional factors on performance in white water slalom

Vondra, Jan January 2016 (has links)
Title: Influence of selected conditional factors on performance in white water slalom. Aims: The aim of the study was to investigate the relationship of selected specific movement abilities being examined modified test battery with the performance of athletes in the water slalom. Methods: It was used field measurements where the applied modified test battery. Using GPS module to determine the distance partial tests from batery. For measuring was used manual measurement. To determine the statistical correlation between the modified battery and performance ability of competitors was used two different coefficients of correlation and regression analysis. According to the order of the test and the race was used nonparametric correlation study - Spearman correlation coefficient. Determining the statistical significance of the relationship of measured times in tests and final time in the nomination races have used the Pearson correlation coefficient. Results: For a statistically significant relationship was determined value when r ≥ 0.8. Spearman's correlation coefficient: In the test at 40 m were obtained these correlation coefficients: Nomination races rs = 0,380952, Czech cup rs = 0,595238. In the test at 80 meters they were obtained these correlation coefficients: nomination races rs = 0,857143,...
28

Seleção de linhagens de feijão para caracteres agronômicos e com qualidade de sementes, nutricionale tecnológica / Selection of common bean lines of high performance agronomic and seeds, nutritional and technological quality

Mambrin, Ritieli Baptista 22 February 2013 (has links)
The common bean (Phaseolus vulgaris L.) has a great national importance and therefore, the development of new cultivars with excellent agronomic performance, seed quality, technological and nutritional, represent an alternative to solve food, social and economic problems. Therefore, experiments were carried out, conducted in three growing seasons: normal rainy 2010/2011, dry season 2011 and normal rainy 2011/2012. Treatments consisted of 16 inbred common bean lines, 12 inbred lines belonging to different breeders and four commercial cultivars used as control. The objectives of this work were: (1) evaluated the effects of the line x environment interaction on the morphological, phenological and grain yield characters of inbred common bean lines and to study the correlation and the direct and indirect association between these characters; (2) evaluate the morphological characteres and the health and physiological quality of bean seeds by different tests, and to determine the association of vigor tests with field emergence to evaluate the morphological and physiological and sanitary quality of seeds advanced lines of beans by different tests, and to determine the association of vigor tests with field emergence seedling in the field; and (3) study genetic variability of common bean lines as grain yield, cooking time and minerals concentration in grains, study the linear correlation between grain yield, cooking time and the minerals concentration in grains and use the Z index to select the common bean lines with superiority for most characters. Significant line x environment interaction was obtained for the seed coat colour, days number for the flowering, pods number per plant, seeds number per plant, 100 seed mass and grain yield. The grain yield and morphological characters don t show correlation coefficients estimates favorable for the selection common bean lines with high grain yield. It was observed that genetic variability exists to proceed with the selection of lines regarding morphological, physiological and sanitary quality of seeds. The lines, TB 02- 24, LP 07-80, LP 08-90, CNFP 10104, Carioca, TB 02-07 and SM 1810 had higher germination and vigor and the lines, Guapo Brilhante, Gen P5-4-3-1 and Gen PR14-2-3 show up with lower germination and vigor. The accelerated aging test is the most appropriate to estimate the effect of bean seeds. The common bean lines showed genetic variability for the grain yield, the cooking time and the calcium and iron concentrations in grains. Correlation of low magnitude was found between the study variables, indicating the no existence of casual correlation. The selection of the Gen Pr 14-2-3 line is recommended because it provided the highest Z index values for most characters. According to the results, genetic variability exists to make selection of lines as the morphological, physiological and sanitary quality of the seed. / O feijão (Phaseolus vulgaris L.) tem uma grande importância nacional e, por isso, o desenvolvimento de novas cultivares com excelentes características agronômicas, com qualidade de sementes, nutricional e tecnológica, representaria uma alternativa para solucionar problemas alimentares, sociais e econômicos. Diante disso, foram conduzidos três experimentos em cultivo de safra 2010/2011, safrinha 2011 e safra 2011/2012. Os tratamentos consistiram de 16 linhagens avançadas de feijão, sendo 12 linhagens pertencentes a diferentes obtentores e quatro cultivares comerciais, utilizadas como testemunhas. Os objetivos deste trabalho foram: (1) avaliar os efeitos da interação linhagem x ambiente sobre os caracteres morfológicos, fenológicos e de produção das linhagens avançadas de feijão e estudar as associações lineares e as relações diretas e indiretas entre esses caracteres; (2) avaliar as características morfológicas e da qualidade sanitária e fisiológica de sementes de feijão por diferentes testes, bem como determinar a associação dos testes de vigor com a emergência de plântulas a campo; e (3) estudar a variabilidade genética das linhagens de feijão quanto à produtividade de grãos, o tempo de cozimento e a concentração de minerais em grãos e a associação linear entre esses caracteres, utilizando o índice Z para selecionar as linhagens com superioridade para a maioria dos caracteres. Interação linhagem x ambiente significativa foi obtida para a coloração do tegumento das sementes, o número de dias da emergência à floração, o número de vagens por planta, o número de sementes por planta, a massa de 100 sementes e a produtividade de grãos. Os caracteres morfológicos não apresentam estimativas de coeficiente de correlação favoráveis à seleção de linhagens de feijão com superioridade para a produtividade de grãos. Foi observado que existe variabilidade genética para se proceder à seleção de linhagens quanto às características morfológicas, qualidade sanitária e fisiológica de sementes. As linhagens Pérola, TB 02-24, LP 07-80, LP 08-90, CNFP 10104, Carioca, TB 02-07 e SM 1810 apresentaram maior germinação e vigor e as linhagens, Guapo Brilhante, Gen P5-4-3-1 e Gen Pr14-2-3 mostram-se com menor germinação e vigor. O teste de envelhecimento acelerado é o mais indicado para estimar o vigor de sementes de feijão. As linhagens de feijão apresentaram variabilidade genética para a produtividade de grãos, o tempo de cozimento e a concentração de cálcio e de ferro em grãos. Correlações de baixa magnitude foram obtidas entre as variáveis em estudo, indicando a inexistência de relação casual. A seleção da linhagem Gen Pr 14-2-3 é recomendável, pois forneceu os maiores valores de índice Z para a maioria dos caracteres.
29

Sistema de visão para guiar um robô de manipulação de cabeçotes fundidos / Industrial robot guided by vision system to handling foundry head blocks

Semim, Ramon Cascaes 13 August 2012 (has links)
Made available in DSpace on 2016-12-12T17:38:31Z (GMT). No. of bitstreams: 1 Ramon Semim.pdf: 14297122 bytes, checksum: 53b76af6dde165965a87172ef45a1143 (MD5) Previous issue date: 2012-08-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents the development of low cost vision system to use on the robotized work cell installed in a foundry finishing line at Tupy S.A. The work cell will use an industrial robot to make the Oil bath and Palletizing of head blocks. The robot job will be moving the parts inside work station. The head blocks input at work cell through a conveyor that moves the parts to robot grasp area. The robotized cell will process 26 different kinds of parts and will be feeding by a human operator, so this is a problem because the head blocks position/orientation on the conveyor will be random. To development was used both low cost webcam and lightning modules. The vision system should find the head block model as well as find its position/orientation. These information are enough to robot grasp the head blocks on the input conveyor. The main image processing tools used on the project are the Pearson Correlation and the Hough Transform. System calibration defines the coordinate system position and orientation, as well as the pixel size. These parameters are important to find out the head block position/orientation. To grasp the parts the robot will reposition and reorient its coordinate system. The industrial robot used in this work is IRB6640, supplied by ABB. It has six degrees of freedom and uses quaternion to define the position/orientation of its end effector. / Este trabalho apresenta o desenvolvimento de um sistema de visão de baixo custo que será utilizado em uma célula robotizada, implantada em uma das linhas de acabamento de cabeçotes da Tupy S.A. Tal célula será responsável pelas operações de oleação e paletização de cabeçotes fundidos, e a função do robô será manipular as peças entre as estações de trabalho. Os cabeçotes entrarão na célula por meio de um transportador com roletes, onde o robô fará a pega das peças para iniciar a sua manipulação. A célula processará 26 tipos diferentes de cabeçotes e será abastecida manualmente, por isso as peças são disponibilizadas ao robô de forma aleatória. Foram empregados uma webcam e módulos de iluminação de baixo custo no projeto. O sistema de visão deve classificar os cabeçotes, de modo a identificar o modelo de cada peça analisada. Outra função do sistema de visão é encontrar a posição e a orientação de cada cabeçote que entrar na célula. Com essas informações o robô será capaz de efetuar a pega de forma correta, independentemente da orientação com a qual o cabeçote entrar na linha. As principais ferramentas de processamento de imagens utilizadas são a Correlação de Pearson e a Transformada de Hough. A calibração do sistema de visão define a posição e a orientação do sistema de coordenadas da câmera, bem como a dimensão de um pixel. Esses parâmetros são fundamentais para que a posição de pega do robô seja encontrada corretamente. Para que seja possível efetuar a pega dos cabeçotes o robô terá de reposicionar e reorientar o seu sistema de coordenadas. O robô usado é o modelo IRB6640, fabricado pela empresa ABB. Ele possui seis graus de liberdade e utiliza quatérnios para definir a orientação do seu efetuador final.
30

Řízení poslechových testů pro subjektivní hodnocení kvality audio signálu / Evaluation of listening tests for subjective assessment of audio quality

Kovařík, Tomáš January 2012 (has links)
The point of this thesis was to perform listening tests. Appropriate methods of performance were selected for these tests, tests were carried out and the data were analyzed using statistical analysis. Then was compiled the resulting interval scale from results of the first test and in the second listening test were determined average values SNR for background noises.

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