Dissertations / Theses: 'Wilcoxon test'

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Kubáňová, Andrea. "Fúze obchodních korporací a jejich vliv na finanční situaci." Master's thesis, Vysoká škola ekonomická v Praze, 2016. http://www.nusl.cz/ntk/nusl-262379.

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This thesis is concerned with domestic mergers of business corporations realized between 2009 - 2012 and their influence on financial situation of chosen subjects. The first part of my paper describes basic theoretical aspects of mergers including their division and motives leading to the realization and their phases. The second chapter consists of trade-legal and accounting adjustment of mergers. Considering practical part, the main focus is on legal modification valid from 31. 12. 2011 to 1. 1. 2012. Following part of this thesis explains accounting solutions of mergers in example, where the immediate impact is shown on realization of the opening balance sheet. The fourth part is concerned with financial analysis, where the sources, users and relevant methods are mentioned. All analysis and results are submitted and described in the final part of my thesis.

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Lousa-Alvin, Alexandra. "Kungsängsverkets kväverening : inverkan på den interna fosforbelastningen i Ekoln." Thesis, Uppsala universitet, Institutionen för ekologi och genetik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-162249.

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Många sjöar är idag påverkade av mänsklig aktivitet, bland annat är 1 % av Sveriges sjöar eutrofierade, däribland Ekoln. Ekoln är en stor sjö i Uppsala län söder om Uppsala som länge varit eutrofierad. Fyrisån och Örsundaån är de största inflödena till Ekoln och Sävjaån är ett betydande biflöde till Fyrisån. Kungsängsverket är Uppsalas reningsverk och har sitt utlopp i Fyrisån och som ett led i att minska eutrofieringen byggdes fosforreningen ut 1972. Fosforhalterna i Ekoln sjönk och algblomningarna blev färre. Kvävereningen byggdes ut 1999 och i detta arbete utvärderas detta reningssteg. Hypotesen är att när ammonium minskar i bottenvattnet kommer syrgasförhållandena att förbättras på grund av minskad ammoniumnedbrytning som förbrukar syrgas. Med ökad halt syrgas är det känt sedan tidigare studier att den interna fosforbelastningen och algblomningen minskar. För att undersöka om det skett en signifikant minskning av näringsämnen i intransporten till Ekoln och av halterna i Ekoln utfördes statistiska test av ämnena för perioden före och perioden efter införandet av kväverening. Intransporterna modellerades även i StormTac. Resultatet visar att det skett en minskning av kväve- och ammoniumtransport och en ökning av fosfor-, fosfat- och TOC-transport. I Ekoln har en minskning påvisats i ammonium-, totalfosforhalt och en ökning i fosfat- och TOC-halt. Ammoniumhalten har minskat i bottenvattnet så den minskade intransporten av ammonium gett en effekt. Fosfor- och fosfathalten har inte förändrats signifikant i bottenvattnet, men det har skett en viss minskning av fosfor och en viss ökning av fosfat i Ekoln perioden 1990-1998 till 2000-2010. Även syrgashalten har ökat i bottenvattnet. Att det inte skett signifikanta förändringar i fosfor, fosfat och syrgas tyder på att intransporten till vattenmassan inte förändrats. Ökade TOC-halter leder till ökad nedbrytning där syrgas förbrukas i bottenvattnet. Det är möjligt att situationen sett ännu värre ut i Ekoln om inte kväveutsläppen minskat.

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Inga, de La Cruz Elvis Edgard. "A abordagem não paramétrica para avaliação da percepção de sustentabilidade do sistema de produção de arroz de terras altas." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/5713.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This study aimed, expand the method of Production Systems Sustainability Perception Rice High -MPSAT Lands. The choice of this method is justified by the fact that it has a good theoretical framework and be easily understood by the actors; however, it lacks nonparametric statistical approach. They were interviewed actors in the production chain of upland rice in Mato Grosso on two occasions, in 2006/07, when the MPSATA and 2014 was developed as part of this research. The methodology transformed the qualitative elements that make up the MPSATA (questions, attributes, indicators, key variables, secondary counselors, primary guiding and sustainability dimensions) for ordinal type and identified the sense of the order of the categories of these elements. Then it verified the significance of matched elements, considering the 2007 and 2014 surveys, with the IBM-SPSS 21. Later the element values were calculated. These elements have as a data source practices and managements carried out along the production chain. The end result of the research was the development of Parametric Method Not for Perception Sustainability Highlands Rice Production System - MPSATA-NP. The results obtained by MPSATA-NP allowed to accept or reject in statistical terms, if there were significant differences between the values of the features found in different eras who were surveyed, revealing that the 221 questions elements, eleven have statistical difference between their medians (three environmental dimension, two of the socioeconomic scale, four in the economic dimension and two territorial dimension). The other sustainability factors have changes compared to paired terms, however, it can´t be said that these elements are in fact different and represent more or less sustainable production conditions. So it follows that not hear significant change in the perception of the actors with respect to the sustainability of the land rice production system in the region.
O presente trabalho teve como objetivo, ampliar o método da Percepção de Sustentabilidade de Sistemas de Produção Arroz de Terras Altas -MPSAT1. A escolha desse método se justifica pelo fato do mesmo possuir uma boa estrutura teórica e ser de fácil compreensão pelos atores, no entanto, carece de abordagem estatística não paramétrica. Foram entrevistados atores da cadeia produtiva de arroz de terras altas em Mato Grosso em dois momentos, em 2006/07, quando o MPSATA foi desenvolvido e 2014, como parte integrante da presente pesquisa. A metodologia utilizada transformou os elementos qualitativos que compõem o MPSATA (quesitos, atributos, indicadores, variáveis essenciais, orientadores secundários, orientadores primários e dimensões de sustentabilidade) para o tipo ordinal e identificou o sentido da ordem das categorias desses elementos. Em seguida foi verificada a significância dos elementos emparelhados, considerando os levantamentos de 2007 e 2014, com o software IBM-SPSS 21. Posteriormente foram calculados os valores dos elementos. Estes elementos possuem como fonte de dados as práticas e manejos realizados ao longo da cadeia produtiva. O resultado final da pesquisa foi a elaboração do Método Não Paramétrico para a Percepção de Sustentabilidade de Sistema de produção de Arroz de Terras Altas – MPSATA-NP. Os resultados obtidos pelo MPSATA-NP permitiram aceitar ou rejeitar em termos estatísticos, se havia diferenças significativa entre os valores dos elementos quesitos encontrados nas diferentes épocas que foram pesquisados, revelando que dos 221 elementos quesitos, onze possuem diferença estatística entre as suas medianas (três da dimensão ambiental, duas da dimensão socioeconômica, quatro da dimensão econômica e dois da dimensão territorial). Os outros elementos de sustentabilidade possuem mudanças, no entanto, não pode-se se afirmar sejam de fato diferentes e que representem condições de produção mais ou menos sustentáveis. Assim, se conclui que não ouve mudança significativa na percepção dos atores com respeito à sustentabilidade do sistema de produção de arroz de terras na região.

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Öhman, Marie-Louise. "Aspects of analysis of small-sample right censored data using generalized Wilcoxon rank tests." Doctoral thesis, Umeå universitet, Statistiska institutionen, 1994. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-7313.

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The estimated bias and variance of commonly applied and jackknife variance estimators and observed significance level and power of standardised generalized Wilcoxon linear rank sum test statistics and tests, respectively, of Gehan and Prentice are compared in a Monte Carlo simulation study. The variance estimators are the permutational-, the conditional permutational- and the jackknife variance estimators of the test statistic of Gehan, and the asymptotic- and the jackknife variance estimators of the test statistic of Prentice. In unbalanced small sample size problems with right censoring, the commonly applied variance estimators for the generalized Wilcoxon rank test statistics of Gehan and Prentice may be biased. In the simulation study it appears that variance properties and observed level and power may be improved by using the jackknife variance estimator. To establish the sensitivity to gross errors and misclassifications for standardised generalized Wilcoxon linear rank sum statistics in small samples with right censoring, the sensitivity curves of Tukey are used. For a certain combined sample, which might contain gross errors, a relatively simple method is needed to establish the applicability of the inference drawn from the selected rank test. One way is to use the change of decision point, which in this thesis is defined as the smallest proportion of altered positions resulting in an opposite decision. When little is known about the shape of a distribution function, non-parametric estimates for the location parameter are found by making use of censored one-sample- and two-sample rank statistics. Methods for constructing censored small sample confidence intervals and asymptotic confidence intervals for a location parameter are also considered. Generalisations of the solutions from uncensored one-sample and two-sample rank tests are utilised. A Monte-Carlo simulation study indicates that rank estimators may have smaller absolute estimated bias and smaller estimated mean squared error than a location estimator derived from the Product-Limit estimator of the survival distribution function. The ideas described and discussed are illustrated with data from a clinical trial of Head and Neck cancer.
digitalisering@umu

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Moradi, Behrouz. "Utvärdering av tre olika metoder för Van Gieson Elastin färgning på Kolorektalcancer i syfte att identifiera venös invasion." Thesis, Örebro universitet, Institutionen för hälsovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-92919.

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Kolorektalcancer är den tredje vanligaste cancerformen hos både män och kvinnor i Sverige där storkärls invasion, venös invasion (VI), är en viktig prognostisk indikator. Noggrann bedömning av VI är särskilt viktigt för patienter med kolorektal cancer i stadium II eftersom det kan påverka beslutet att erbjuda adjuvant behandling. Histologisk bedömning av VI kan vara utmanande på rutinmässig Hematoxylin och Eosin färgning (H&E). Elastinfärgning med syfte att identifiera elastinfibrer i kärlväggen kan underlätta bedömning av VI. I dagsläget finns inte någon bra elastinfärgning som kan användas rutinmässigt hos klinisk patologi i Värmland, Centralsjukhuset Karlstad, prover måste skickas till annat laboratorium vilket är tidskrävande. Denna studie ska finna den optimala färgningsmetoden för elastin genom att utvärdera tre olika färgningsmetoder för elastin fibrer. Färgningens resultat bedömdes rent histokemiskt av överläkare enlig kriterierna, frånvaro av avsedda kärl (skala 0–1), specifik infärgning (skala 0–1), specifik infärgnings intensitet (skala 1–3) och ospecifik infärgning (skala 0–1) och data samlades för respektive metod. Resultatet tyder på att rent histokemiskt är den manuella elastinfärgning metoden från Region Jönköpings län konsekvent och visade signifikant skillnad. Därför metoden är potentiellt användbar för den större frågeställningen om storkärlsinväxt i kolorektal cancer samt rekommenderas starkt som en rutinmässig elastinfärgning till klinisk patologi i Värmland, Centralsjukhuset Karlstad.
The third most common form of cancer in both men and women in Sweden is Colorectal cancer. Prognostic indicators of colorectal cancer include Large vessel invasion and venous invasion (VI). Careful assessment of VI is of particular interest especially with patients having stage II colorectal cancer. This is because it may influence decisions to offer adjuvant therapy. Accurate histological assessment of VI can be challenging on routine hematoxylin and eosin staining. But staining that can identify the elastin fibers in the vessel can enhance the assessment of VI. Currently, there is not any good Elastin staining that can be routinely used in clinical pathology in Värmland, Karlstad Central Hospital. Therefore, samples are required to be sent to other laboratories which in effect is time consuming. This study is aimed at finding an optimal elastin staining method through evaluations of three different staining methods for elastin fibers. Staining results were assessed histochemically by the chief physician according to the following criteria, absence of intended vessels (scale 0–1), specific staining (scale 0–1), specific staining intensity (scale 1–3) and nonspecific staining (scale 0–1), while different data were collected for each method. The results indicate that purely histochemically, elastin staining-manual method Region Jönköping County is consistent and significant. Therefore, the method is potentially useful for the detection of colorectal cancer and is strongly recommended as a routine elastin staining for clinical pathology in Värmland, Karlstad Central Hospital.

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Zhang, Yan. "The impact of midbrain cauterize size on auditory and visual responses' distribution." unrestricted, 2009. http://etd.gsu.edu/theses/available/etd-04202009-145923/.

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Thesis (M.S.)--Georgia State University, 2009.
Title from file title page. Yu-Sheng Hsu, committee chair; Xu Zhang, Sarah. L. Pallas, committee members. Description based on contents viewed June 12, 2009. Includes bibliographical references (p. 37). Appendix A: SAS code: p. 38-53.

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NASCIMENTO, Rosângela Silveira do. "Análise de correlação de longo alcance no registro da atividade elétrica cortical no fenômeno da depressão alastrante em ratos." Universidade Federal Rural de Pernambuco, 2008. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5308.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
In the present work we analyze the dynamics of electrical cortical activity during the phenomenon of spreading depression (DA) and during the periods before and after this phenomenon. The characteristic of DA is reduced amplitude of spontaneous electrical activity that occurs in neural tissue after the application of stimulus that can be electrical, chemical, mechanical, luminous etc. In order to study properties of time series of electrical cortical activity recorded by ECoG (electrocortiogram) before,during and after DA, we apply Detrended Fluctuation Analysis(DFA). This method is designed to quantify long term correlations (memory) in temporal series such ECoG register. The method was successfully applied in studies of DNA sequences and non-stationary time series as heart rate variability, stride intervals, financial time series etc. The application of DFA results in scaling exponentα that quantifies correlation properties of nonlinear dynamical systems. This experiment indicates if temporal series posses long term correlations. In this work we calculate exponent α for different intervals: control (before the stimulus), after the stimulus, during the avalanche, during DA and after DA for two experimental groups of rats, nourished and malnourished. For both experimental groups the values of exponent α indicates persistent behavior for all intervals except during the avalanche in which correlations degrade. The presence of long term correlations in physiological time series observed in healthy organisms represents complexity that guaranties the organism’s adaptability to stress and disease. The absence of correlations during the avalanche indicates the loss of this complexity. Non-parametric Wilcoxon test was used to compare mean values of exponents α for all intervals of analyzed time series. In cases of nourished rats, the mean values ofα are significantly different for control, stimulus, avalanche, DA and after-DA intervals. Wilcoxon test was also used to compare mean values of α for corresponding intervals for the two experimental groups. The result is significant difference in mean values of α for control, stimulus avalanche, DA and after DA intervals between two experimental groups. The hypothesis that α =0.5 for avalanche intervals was not rejected by test, confirming the loss of correlations in this phase. Comparison of mean values of α for different intervals (control, stimulus, DA and after DA) with avalanche using the Wilcoxon test results in significant difference between two groups.
O presente estudo se propõe a analisar a dinâmica da atividade elétrica cortical durante o fenômeno da depressão alastrante (DA) e nos períodos que antecede e sucede o fenomêno. A DA é caracterizada pela redução da amplitude da atividade elétrica espontânea que ocorre no tecido neural, após a aplicação de um estímulo de natureza elétrica, química, mecânica, luminosa e outros. Visando estudar o comportamento da série temporal da atividade elétrica cortical, registrada no ECoG (eletrocorticograma), durante a DA e nos períodos que precede e sucede o fenômeno, foi aplicado o método do DFA (Detrended Fluctuation Analysis). Este método permite quantificar a existência de correlação de longo alcance (memória) numa série temporal, como é o caso do registro do ECoG. Anteriormente, o método foi aplicado em seqüências de DNA e no estudo de séries temporais não estacionárias, tais como, dinâmica da variabilidade cardíaca, flutuações de eletroencefalograma de humanos, intervalos entre passos sucessivos de humanos, séries econômicas e outros. A aplicação do DFA numa série temporal permite a determinação de um expoente de escalonamento α, que pode contribuir para a compreensão das propriedades dos sistemas dinâmicos não lineares. Este expoenteα revela se a série temporal apresenta correlação de longo alcance ou não. Neste trabalho os expoentes α foram calculados nas fases de controle, estímulo, avalanche, DA e após a DA para o ECoG, em dois grupos experimentais, ratos nutridos e ratos desnutridos. Em ambos os grupos experimentais, os valores obtidos para o expoente de escalonamento α denotam que a série temporal do ECoG apresenta correlação persistente (comportamento da série no presente se mantém no futuro) em todas as fases do processo com exceção da avalanche, período no qual ocorre perda de correlação. A presença de correlação de longo alcance numa série temporal biológica é uma resposta sempre observada em organismos saudáveis cuja complexidade do sinal registrado garante a adaptabilidade do organismo a situações de estresse e/ou distúrbios. Enquanto a ausência de correlação, observada na avalanche, indica a perda de propriedades fractais nos sistemas fisiológicos. O uso do método não-paramétrico de Wilcoxon, para comparar os valores médios dos expoentes α obtidos para o grupo de animais nutrido, durante as fases de controle, estimulação, DA, após DA, revelou que essas diferentes fasesdiferem significativamente. Os valores médios dos expoentes α obtidos para o grupo de animais desnutrido, durante as fases de controle, estimulação, DA, após DA, também não foram significativamente diferentes, quando comparados pelo método de Wilcoxon. Na comparação dos valores médios de α nas fases de controle, estimulação, DA, após DA entre os dois grupos de animais (nutrido e desnutrido) o teste de Wilcoxon revelou que as médias dos expoentes α em cada fase para os animais nutridos diferem significativamente daquelas obtidas para os animais desnutridos. Na avalanche a hipótese de que o expoente α é igual a 0,5, não foi rejeitada pelo teste de Wilcoxon, ou seja, o teste confirmou a perda de correlação nessa fase. Na comparação entre as médias dos expoentes α nos diferentes intervalos (controle, estimulação, DA, após DA) com o valor do expoente α na avalanche, o teste de Wilcoxon acusou diferença significativa tanto no grupo dos nutridos como no grupo dos desnutridos.

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FOSTER, WARREN R. "THE IMPACT OF A BIDDER WORKSHOP ON SELF-EFFICACY." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1171310672.

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Fagerlund, Elias, and Talukder Mashrukh. "Where to Invest? : Choosing the optimal stock market for investing in a cross-listed Nordic firm." Thesis, Umeå universitet, Företagsekonomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-60556.

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The purpose of this study is to investigate whether the location of buying stocks in a Nordic cross-listed company matters in terms of 1) earning abnormal returns, or 2) gaining in optimizing the amount spent by buying the specific stock cheap. Nowadays, markets are becoming more integrated and if we believe in the efficient market hypothesis, prices of the same class of stocks paying the same dividend annually, of an MNC must be the same irrespective of the stock exchange it is listed upon. Though efficient market hypothesis exists in theory, market imperfection is a reality. All the Nordic (Swedish, Finnish, Norwegian, Danish and Icelandic) firms listed on foreign stock exchanges in addition to their home market have been included in the sample. In fact, this sample represents 100% of the population. The daily prices of cross-listed stocks have been analyzed and conclusions have been drawn based on the mean returns and mean prices along with Wilcoxon Signed-Rank test statistics. The data have been analyzed over the last ten years capturing the recent economic cycle. The whole period has also been divided into three sub-periods to establish comparisons with the whole period. This paper reports that even though returns on cross-listed stocks are statistically same over all periods, prices of the stocks vary according to the location of listing. That is, investors can buy from a stock exchange where the specific stock is underpriced thereby decreasing the amount invested in absolute term and optimizing the amount spent if not the return. The returns and prices have analyzed using the local currency of the MNC’s country of origin and Special Drawing Rights (SDRs). No considerable differences on the returns or pattern of price movements have been observed while using two currencies.

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Matsouaka, Roland Albert. "Contributions to Imputation Methods Based on Ranks and to Treatment Selection Methods in Personalized Medicine." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10078.

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The chapters of this thesis focus two different issues that arise in clinical trials and propose novel methods to address them. The first issue arises in the analysis of data with non-ignorable missing observations. The second issue concerns the development of methods that provide physicians better tools to understand and treat diseases efficiently by using each patient's characteristics and personal biomedical profile. Inherent to most clinical trials is the issue of missing data, specially those that arise when patients drop out the study without further measurements. Proper handling of missing data is crucial in all statistical analyses because disregarding missing observations can lead to biased results. In the first two chapters of this thesis, we deal with the "worst-rank score" missing data imputation technique in pretest-posttest clinical trials. Subjects are randomly assigned to two treatments and the response is recorded at baseline prior to treatment (pretest response), and after a pre-specified follow-up period (posttest response). The treatment effect is then assessed on the change in response from baseline to the end of follow-up time. Subjects with missing response at the end of follow-up are assign values that are worse than any observed response (worst-rank score). Data analysis is then conducted using Wilcoxon-Mann-Whitney test. In the first chapter, we derive explicit closed-form formulas for power and sample size calculations using both tied and untied worst-rank score imputation, where the worst-rank scores are either a fixed value (tied score) or depend on the time of withdrawal (untied score). We use simulations to demonstrate the validity of these formulas. In addition, we examine and compare four different simplification approaches to estimate sample sizes. These approaches depend on whether data from the literature or a pilot study are available. In second chapter, we introduce the weighted Wilcoxon-Mann-Whitney test on un-tied worst-rank score (composite) outcome. First, we demonstrate that the weighted test is exactly the ordinary Wilcoxon-Mann-Whitney test when the weights are equal. Then, we derive optimal weights that maximize the power of the corresponding weighted Wilcoxon-Mann-Whitney test. We prove, using simulations, that the weighted test is more powerful than the ordinary test. Furthermore, we propose two different step-wise procedures to analyze data using the weighted test and assess their performances through simulation studies. Finally, we illustrate the new approach using data from a recent randomized clinical trial of normobaric oxygen therapy on patients with acute ischemic stroke. The third and last chapter of this thesis concerns the development of robust methods for treatment groups identification in personalized medicine. As we know, physicians often have to use a trial-and-error approach to find the most effective medication for their patients. Personalized medicine methods aim at tailoring strategies for disease prevention, detection or treatment by using each individual subject's personal characteristics and medical profile. This would result to (1) better diagnosis and earlier interventions, (2) maximum therapeutic benefits and reduced adverse events, (3) more effective therapy, and (4) more efficient drug development. Novel methods have been proposed to identify subgroup of patients who would benefit from a given treatment. In the last chapter of this thesis, we develop a robust method for treatment assignment for future patients based on the expected total outcome. In addition, we provide a method to assess the incremental value of new covariate(s) in improving treatment assignment. We evaluate the accuracy of our methods through simulation studies and illustrate them with two examples using data from two HIV/AIDS clinical trials.

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Burson, Patrick A. R. "An analysis of the impact of data errors on backorder rates in the F404 engine system." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FBurson.pdf.

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Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2003.
Thesis advisor(s): Robert A. Koyak, Samuel E. Buttrey. Includes bibliographical references (p. 63-64). Also available online.

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Tang, Tian. "Infrared Spectroscopy in Combination with Advanced Statistical Methods for Distinguishing Viral Infected Biological Cells." Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/math_theses/59.

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Fourier Transform Infrared (FTIR) microscopy is a sensitive method for detecting difference in the morphology of biological cells. In this study FTIR spectra were obtained for uninfected cells, and cells infected with two different viruses. The spectra obtained are difficult to discriminate visually. Here we apply advanced statistical methods to the analysis of the spectra, to test if such spectra are useful for diagnosing viral infections in cells. Logistic Regression (LR) and Partial Least Squares Regression (PLSR) were used to build models which allow us to diagnose if spectral differences are related to infection state of the cells. A three-fold, balanced cross-validation method was applied to estimate the shrinkages of the area under the receiving operator characteristic curve (AUC), and specificities at sensitivities of 95%, 90% and 80%. AUC, sensitivity and specificity were used to gauge the goodness of the discrimination methods. Our statistical results shows that the spectra associated with different cellular states are very effectively discriminated. We also find that the overall performance of PLSR is better than that of LR, especially for new data validation. Our analysis supports the idea that FTIR microscopy is a useful tool for detection of viral infections in biological cells.

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Luo, Shan. "Advanced Statistical Methodologies in Determining the Observation Time to Discriminate Viruses Using FTIR." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/math_theses/86.

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Fourier transform infrared (FTIR) spectroscopy, one method of electromagnetic radiation for detecting specific cellular molecular structure, can be used to discriminate different types of cells. The objective is to find the minimum time (choice among 2 hour, 4 hour and 6 hour) to record FTIR readings such that different viruses can be discriminated. A new method is adopted for the datasets. Briefly, inner differences are created as the control group, and Wilcoxon Signed Rank Test is used as the first selecting variable procedure in order to prepare the next stage of discrimination. In the second stage we propose either partial least squares (PLS) method or simply taking significant differences as the discriminator. Finally, k-fold cross-validation method is used to estimate the shrinkages of the goodness measures, such as sensitivity, specificity and area under the ROC curve (AUC). There is no doubt in our mind 6 hour is enough for discriminating mock from Hsv1, and Coxsackie viruses. Adeno virus is an exception.

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Öhman, Marie-Louise. "Aspects of analysis of small sample right censored data using generalized Wilcoxon rank tests /." Umeå : Univ, 1994. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=006873072&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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15

Liu, Yunfeng. "Tests of Bivariate Stochastic Order." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20257.

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The purpose of this thesis is to compare rank-based tests of bivariate stochastic order. Given two bivariate distributions $F$ and $G$, the general problem we are dealing with is to test $H_0: F=G$ against $H_1:F

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16

Nyström, Josefina. "Multivariate non-invasive measurements of skin disorders." Doctoral thesis, Umeå University, Chemistry, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-865.

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The present thesis proposes new methods for obtaining objective and accurate diagnoses in modern healthcare. Non-invasive techniques have been used to examine or diagnose three different medical conditions, namely neuropathy among diabetics, radiotherapy induced erythema (skin redness) among breast cancer patients and diagnoses of cutaneous malignant melanoma. The techniques used were Near-InfraRed spectroscopy (NIR), Multi Frequency Bio Impedance Analysis of whole body (MFBIA-body), Laser Doppler Imaging (LDI) and Digital Colour Photography (DCP).

The neuropathy for diabetics was studied in papers I and II. The first study was performed on diabetics and control subjects of both genders. A separation was seen between males and females and therefore the data had to be divided in order to obtain good models. NIR spectroscopy was shown to be a viable technique for measuring neuropathy once the division according to gender was made. The second study on diabetics, where MFBIA-body was added to the analysis, was performed on males exclusively. Principal component analysis showed that healthy reference subjects tend to separate from diabetics. Also, diabetics with severe neuropathy separate from persons less affected.

The preliminary study presented in paper III was performed on breast cancer patients in order to investigate if NIR, LDI and DCP were able to detect radiotherapy induced erythema. The promising results in the preliminary study motivated a new and larger study. This study, presented in papers IV and V, intended to investigate the measurement techniques further but also to examine the effect that two different skin lotions, Essex and Aloe vera have on the development of erythema. The Wilcoxon signed rank sum test showed that DCP and NIR could detect erythema, which is developed during one week of radiation treatment. LDI was able to detect erythema developed during two weeks of treatment. None of the techniques could detect any differences between the two lotions regarding the development of erythema.

The use of NIR to diagnose cutaneous malignant melanoma is presented as unpublished results in this thesis. This study gave promising but inconclusive results. NIR could be of interest for future development of instrumentation for diagnosis of skin cancer.

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17

Janstad, Tobias. "Case study of a contract system : considering pulp prices from 1996-2006." Thesis, Växjö University, School of Mathematics and Systems Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1684.

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Södra Cell sells 1 900 000 ton pulp every year. Of this 490 000 tonne is sold with a contract system based on a pricing index called PIX NBSK. This index was started in 1996 and reflects the price of pulp from conferious forest. We study the NBSK PIX value of softwood from October 1996 to December 2006.

People working in this branch known that there is strong periodicity in the prices. We use predictive analysis to see if clients can benefit from the periodicity and use the options in the contract system Södra offers today. We conclude that a drawback for the current contract system is that there are too many contracts in proportion to the duration time that is one year for all contracts. Using a time series model called ARMA we make successfull predictions the price difference between two contracts. Based on this prediction we change between these contracts, reducing the price with 0.81% in mean during 1997-2006. Due to the total turnover, if all clients would used such predictions during 1997-2006 Södra's income would have been reduced with 2.77 million USD a year in mean.

The prices used before PIX are called list prices. The list prices seem to behave like the PIX index. Supposing that the same contract system we see in PIX today was used 1975-2006 with the list price as the base index I made a prediction of the list prices from 1986-2006. Thanks to my predictions, if I had been a client during this period and under mentioned considerations I would have been buying pulp to a price reduced with 0.57%.

If clients had known the PIX between 1996-2006 in say 1995 Södra's contract system based on PIX would give them a price reduction that were 1.5% in mean during 1996-2006. Price reduction is not possible all years, but when it occurs it can be as big as 3% of the price. Suppose the clients always choose the contract with the lowest price and thereby get a reduced price over time. Then with 95% probability over a long period the price reduction is somewhere in between 0.4-2.7%.

To strangle this price reduction possibility for the clients there are two ways to go: either reduce the number of contracts or extend the duration time of the contracts.

To find a suitable duration time, we do spectral density estimation to get indications of which periods that are most important. From this we see that PIX index has a period of five years, wavelet approximated PIX index has 3.4 years and the list prices has a period of 5.6 years. This indicates that current duration time one year is too short. Therefore if it wouldn't effect Södra's clients, an extension of the duration time from one to five years would be good.

If Södra don't extend the duration time of the contracts my recommendation is to have fewer contracts. The possibility to change between the contracts ''average last three months'' and ''average current month'' every other year is the weakest point of today's system. Therefore I recommend stop selling pulp to the contract ''average PIX last three months''.

We can't prove any longterm difference between the contracts. If Södra chooses to have just one contract from this point of view it does not matter which one they choose. However, it seems like a good idea to follow the global market and therefore I recommend to choose ''average PIX current month'' rather than ''average PIX last three months'' which lags behind the market front. Since the price ''average current month'' is available at FOEX web page I think Södra should choose this contract if they decide to have only one contract.

Södra Cell säljer årligen 1 900 000 ton pappersmassa. Av denna mängd säljs 490 000 ton enligt ett kontraktsystem baserat på ett prisindex som heter PIX NBSK. Detta index introducerades 1996 och reflekterar priset på pappersmassa gjord av barrträd. Jag studerar priset på indexet från Oktober 1996 till December 2006.

Dagens kontraktsystem är baserat på kontrakt med löptiden ett år. Jag undersöker om man kan prediktera prisskilllnaden mellan kontrakten, dra nytta att dagens löptid som bara är ett år och välja det kontrakt som ger det billigaste priset så ofta att priset över lång tid reduceras. När man predikterar gör man en uppskattningen av framtiden utifrån en modell av hur framtid beror på dåtid och nutid. Den modell jag har använt kallas ARMA. Denna tillsammans med priserna på pappersmassa från 1975 och framåt gav mig ett fruktbart sätt att förutsäga priserna. Resultatet blev ett pris reducerat med 0.81% i medel under perioden 1996-2006. Eftersom Södra ha så stor försäljningsvolym skulle de ha förlorat 2.27 miljoner dollar per ton i medel om alla kunder ha spekulerat utifrån den modellen jag använde.

Om dagens kontraktsystem hade börjat användas 1975 med listpriserna som bas hade en kund som använt min prediktionsmetod fått ett pris reducerat med 0.57% under perioden 1986-2006.

Om kunderna i förväg hade vetat priset under 1996-2001 gav det nuvarande systemet en reducerad medelintäkt med 1.5% av priset. Enskilda år reducerades intäkten med så mycket som 3%. Beräknar man konfidensintervall för prisreduktionerna så inser man att på lång sikt kommer dessa vara av storleksordningen 0.4-2.7% med sannolikheten 95%. Detta förutsatt att klienterna kan se in i framtiden. Siffran 2.7% alltså ett mått på hur stor risk man tar med dagens system. Jag tror inte att klienterna kommer reducera priset med 2.7% med nuvarande system, men det är en övre gräns.

De gynsamma prediktionerna har sitt ursprung i att det finns periodicitet i priserna. Jag undersöker denna periodicitet med spektralanalys. Periodiciteten för PIX indexet är starkast kring 5 år. En wavelet-approximation av PIX-indexet hade störst periodicitet kring 3.4 år. Listpriserna hade starkast periodicitet kring 5.6 år. Detta indikerar att den nuvarande löptiden, ett år, är för kort. En lämpligare löptid för kontrakten är 5 år.

Förmodligen är fem års löptid alltför lång tid att binda sig för många kunder. Därför föreslår jag att man reducerar antalet kontrakt istället. Den största svagheten i dagens system är den korta löptiden tillsammans med kontrakten ''average current month'' och ''average last three months''. Jag rekommenderar att man slutar erbjuda kontraktet ''average last three months''. Det allra säkraste är att endast erbjuda ett kontrakt. Vi har inte kunnat påvisa några skillnader över lång sikt mellan kontrakten såtillvida att något kontrakt skulle ge ett lägre medelpris än ett annat. Ur den aspekten är det godtyckligt vilket kontrakt man väljer, men det verkar vettigt att följa den globala marknaden. Därför är det eftersläpande kontraktet ''average PIX last three months'' inte att rekommendera, välj heller ''average PIX current month''. Ett annat argument för att välja ''average PIX current month'' är att dessa priser finns på FOEX hemsida och inga extra beräkningar behöver göras.

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18

Khan, Abdul Kareem. "Electrostaticanalisys the Ras active site." Doctoral thesis, Universitat Pompeu Fabra, 2009. http://hdl.handle.net/10803/7161.

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La preorganització electrostàtica del centre actiu s'ha postulat com el mecanisme genèric de l'acció dels enzims. Així, alguns residus "estratègics" es disposarien per catalitzar reaccions interaccionant en una forma més forta amb l'estat de transició, baixant d'aquesta manera el valor de l'energia dactivació g cat. S'ha proposat que aquesta preorientació electrostática s'hauria de poder mostrar analitzant l'estabilitat electrostàtica de residus individuals en el centre actiu.
Ras es una proteïna essencial de senyalització i actúa com un interruptor cel.lular. Les característiques estructurals de Ras en el seu estat actiu (ON) són diferents de les que té a l'estat inactiu (OFF). En aquesta tesi es duu a terme una anàlisi exhaustiva de l'estabilitat dels residus del centre actiu deRas en l'estat actiu i inactiu.
The electrostatic preorganization of the active site has been put forward as the general framework of action of enzymes. Thus, enzymes would position "strategic" residues in such a way to be prepared to catalyze reactions by
interacting in a stronger way with the transition state, in this way decreasing the activation energy g cat for the catalytic process. It has been proposed that
such electrostatic preorientation should be shown by analyzing the electrostatic stability of individual residues in the active site.
Ras protein is an essential signaling molecule and functions as a switch in the
cell. The structural features of the Ras protein in its active state (ON state) are different than those in its inactive state (OFF state). In this thesis, an exhaustive analysis of the stability of residues in the active and inactive Ras active site is performed.

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19

Hansson, Mats. "Analys av argument som uttrycks i samband med ett levande rollspel om embryonala stamceller : En designbaserad studie med analysverktyget TKE av hur argumentens kvalitet utvecklas under en undervisningssekvens." Thesis, Stockholms universitet, Institutionen för matematikämnets och naturvetenskapsämnenas didaktik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-114131.

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Diskussioner om användandet av embryonala stamceller är exempel på ett område där naturvetenskapliga teorier möter en diskussion i samhällshällsdebatten. Värderingar med t ex etiska utgångspunkter påverkar hur naturvetenskaplig forskning bedrivs och hur resultaten från denna forskning tillämpas. När sådana frågor, samhällsfrågor med naturvetenskapligt innehåll, SNI (socioscientific issues, SSI), tas upp i undervisningen är det angeläget att belysa att det i samhällsdebatten förekommer en diskussion där företrädare för ståndpunkter för fram olika argument i frågan. Ett sätt att möta detta behov är att designa en undervisningssekvens som innehåller en rollspelsdiskussion kring en dagordning. Ytterligare bidrag till utvecklingen av argument kan användandet av skrivramar ge. I denna undersökning har ett levande rollspel om embryonala stamceller designats, och några av komponenterna i denna undervisningssekvens har undersökts i en designbaserad studie vid fyra gymnasieskolor. Ett analysverktyg har satts samman av befintliga analysverktyg ur forskningslitteraturen med en del med vars hjälp man kan studera argumentstruktur baserat på Toulmins argument patterns (T), en annan del som tar fasta på inslaget av specifika biologiska kunskaper (K) och en tredje del som belyser den epistemiska nivån (E). TKE- analys av argument kan ge ett underlag som kan användas till att belysa betydelsen av hur undervisningen i SSI läggs upp för elevernas möjligheter att utveckla naturvetenskapliga argument av hög kvalitet. Med analysverktyget TKE kan man se hur olika delar av en undervisningssekvens påverkar utvecklingen av argumentens kvalitet. Eftersom de tre delarna av TKE innehåller olika kvalitativt beskrivna och rangordningsbara nivåer så är det möjligt att koda argumentens kvalitet och därefter genomföra en hypotesprövning. Vid en sådan hypotesprövning bör man beakta att de kodade resultaten är parade ordinaldata och att hypotesprövning kan ske med Wilcoxons teckenrangtest. Genom analys av argument med analysverktyget TKE kan man belysa kvaliteter på olika nivåer hos argument. De kvaliteter som syns i TKE-analys av argument är också kvaliteter som ger belägg vid bedömning enligt skolverkets kunskapskrav aspekt fyra för biologikurserna i gymnasieskolan. TKE - analys visar i att argumentens kvalitet är god efter förberedelserna med skrivramarna som stöd. Rollspelsdiskussioner med konsensuskrav verkar påverka argumentens kvalitet i kvalitetsklassen E men i övrigt kan det inte påvisas att rollspelsdiskussionen bidrar till att argumenten av högre kvalitet kan uttryckas. Men argumentens kvalitet kan förbättras signifikant genom aktiviteter efter rollspelsdiskussionen som att man efter denna erbjuder skriftlig återkoppling på skrivna argument.
Discussions about the use of embryonic stem cells is an example of a socioscientific issue (SSI) where the use of scientific progresses meets the social debate where values with for example ethic points of view affect the discussion. When such topics, socioscientific issues, are included in educational instructions, is it important to illustrate that a discussion takes place in the social debate where arguments based on different points of view are presented. One way to meet this need is to design a teaching sequence, which contains a live role play with a discussion, where students are given the opportunity to exchange arguments with scientific grounds and to listen to others. The use of writing frames is a further contribution to the development of argumentation instruction for an SSI. In this study, a live role play is designed on the socioscientific issue embryonic stem cells. Parts of these teaching sequences have been analyzed in a design based study in four upper secondary schools. An analysis tool has been developed based on the didactic literature with one part that shows the structure of arguments based on Toulmin’s argument patterns (T), a second part that focus on the specific biology knowledge (K) and a third part that makes it possible to analyze the epistemic level (E) of the argument. TKE-analysis could be useful when studying the quality of arguments to show the importance of how instructions for teaching in SSI are structured in order to give the students opportunity to develop scientific arguments of high quality. When analyzing arguments with TKE it is possible to see how different parts of teaching sequences are affecting the development of the quality of arguments with a focus on the structural and conceptual qualities. Since it is possible to rank the quality levels of the three parts of TKE it is possible to test hypotheses. In such a hypothesis-testing it is important to notice that the results from the TKE analysis are paired ordinal data and that hypothesis-testing could be done with Wilcoxon’s sign rank test. By using TKE–analysis it is possible to get information about the quality of arguments of different levels. The qualities of arguments that are illustrated in TKE-analysis are qualities that also are important in assessment with the grade criteria aspect four for the scientific courses from the Swedish national agency for education. TKE-analyses of shows that the qualities of arguments are good after the arguments are prepared supported by the writing frames. The role play discussion affects only the epistemic level of arguments only in the consensus discussion. In the other quality categories, T and K there were no significant increase of the argument quality after the role play discussions. But according to TKE-analysis, the quality of arguments could be increased significantly by offering activities after the role play discussion such as written feed back on written arguments.

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20

Roothaer, Xavier. "Approche multi-échelle du comportement mécanique des os porteurs et non-porteurs : vers une personnalisation des modèles numériques EF de l'être humain." Thesis, Valenciennes, Université Polytechnique Hauts-de-France, 2019. http://www.theses.fr/2019UPHF0020.

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Le squelette humain a pour fonction de protéger les organes internes tout en participant au système de locomotion. Aﬁn d’en assurer la rigidité mécanique, l’os cortical est présent dans toutes les parties du squelette. Le remodelage osseux, processus dynamique, est actif tout au long de la vie. Il permet à l’os cortical d’adapter sa géométrie et son architecture interne en fonction des contraintes qui lui sont appliquées. Étant un processus complexe, le remodelage osseux est amené à dysfonctionner chez les personnes âgées et fragiliser leurs os. Ainsi, cette thèse étudie les os porteurs et non porteurs humains en se concentrant sur le fémur et l’humérus. La revue de la littérature, eﬀectuée dans le chapitre 1, met en évidence plusieurs verrous scientiﬁques à résoudre. En eﬀet, pour diverses raisons pratiques, le fémur est très largement étudié, délaissant l’étude des autres os. Cela a pour eﬀet d’en impacter les données matériaux utilisées par les modèles numériques du corps humain, souvent extraites d’études très anciennes et obsolètes dont les sujets humains diﬀèrent. De plus, les études architecturales sont, pour la plupart, limitées à des analyses en 2D et ne sont pas adaptées par rapport à l’architecture osseuse complexe. Par conséquent, le second chapitre décrit une méthode innovante capable d’analyser et de quantiﬁer l’architecture en 3D à partir de scans tomographiques. Les canaux, connectivités et BMUs, berceaux du remodelage osseux, sont automatiquement détectés. 77 échantillons, prélevés sur humérus et fémurs gauche et droit, sont scannés et quantiﬁés à partir de cette méthode. Étant donné que de nombreuses caractéristiques, jamais mesurées auparavant, sont obtenues, des essais de traction et d’indentation sont eﬀectués aﬁn de comprendre et de mettre en évidence l’impact de l’architecture sur le comportement mécanique. Par conséquent, l’intégralité des échantillons, précédemment scannée, est testée. Dans l’objectif d’extraire des tendances générales, les humérus et fémurs sont comparés suivant diﬀérents tests statistiques. De même, l’impact de la latéralité est aussi étudié. Pour terminer, une étude de corrélation, suivie d’une étude de régressions, est eﬀectuée aﬁn de fournir des fonctions polynomiales destinées à prédire le comportement mécanique à partir d’une simple étude architecturale
The human skeleton aims at participating to the locomotor system, protecting and serving as brackets for the internal organs. To ensure the mechanical stiﬀness of the entire body, the cortical bone can be found in every part of the skeleton. A dynamic process occurs throughout the life and is named bone remodelling. This process adapts the cortical bone architecture and the shape of bones according to their functions. Due to its complexity, bone remodelling can defect in the elderly and weakens bones. This thesis studies the bearing and non-bearing long human bones by focusing on the humerus and femur. A survey of the state of the art, detailed in the ﬁrst chapter, reveals several lacks. First, the femur is widely investigated compared to the other bones and this unbalance creates a lack of data for the other bones. Therefore, inputs for numerical human models come from deprecated and contradictory studies where the extra-individual diﬀerences impact the trends. Second, architectural studies are mainly limited to in-plane assessment whereas the vascular network is complex and needs more robust analyses. Thus, the second chapter describes an innovative method to 3D assess the cortical vascular network from tomographic data. This Python script automatically detects canals, connectivity and Bone Multicellular Units (BMUs), cradle of the bone remodelling activity. Then, 77 samples from left and right femurs and humeri of ten human cadavers are scanned and analysed using this method. As this method provides numerous novel features of the cortical architecture, tensile and indentation tests are also carried out in order to understand and exhibit the impact of the architecture on the mechanical behaviour. Hence, all the scanned samples are tested and available for statistical analysis. So as to identify global trends, humerus and femur are compared using diﬀerent statistical tests. Likewise, the bias impact is also investigated. Finally, a correlation study followed by a regression study is described so as to provide polynomial functions in order to be used to predict the mechanical behaviour from an architectural study

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21

Huang, Yi-hsuan, and 黃怡萱. "Wilcoxon Rank Sum Test for Interval Censored Data." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/57947053170538616505.

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碩士
國立高雄大學
統計學研究所
102
Wilcoxon rank sum test is a useful nonparametric method for testing the equality of distribution of two populations. It has greater efficiency than the t-test on heavy tail distribution, and is nearly as efficient as the t-test on normal distribution. In this paper, an extension of Wilcoxon test for interval censored data which are often found in longitudinal studies is provided. A series of simulation is given to show the performance of the proposed method and the power of our proposed test is better than Finkelstein (1986) and Sun (1996) in some circumstance. We also use our proposed teat to analyze three examples and show the results.

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Shen, Ching-Fu, and 沈清福. "A Weighted Wilcoxon-Type Rank Test for Interval-Censored Data." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/77062299331027697269.

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博士
國立中山大學
應用數學系研究所
101
Interval-censored (IC) failure time data are often observed in medical follow-up studies and clinical trials where subjects can only be followed periodically and the failure time can only be known to lie in an interval. In this paper, we propose a weighted Wilcoxon-type rank test for the problem of comparing two IC samples. Under a very general sampling technique developed by Fay (1999), the mean and variance of the test statistic under the null hypothesis can be derived. Through simulation studies, we ‾nd that the performance of the proposed test is better than that of the two existing Wilcoxon-type rank tests proposed by Mantel (1967) and Peto and Peto (1972). The proposed test is illustrated by means of an example involving patients in AIDS cohort studies.

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23

Alharbi, Abdulwahab. "The Use of Net Benefit in Modeling Non-Proportional Hazards." Thesis, 2020. http://hdl.handle.net/1805/24746.

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Indiana University-Purdue University Indianapolis (IUPUI)
Background: The hazard ratio (HR), representing the quantified estimate of treatment effect in survival analysis, measures the instantaneous relative difference of failure risk between two groups. The HR is typically assumed to be independent of time; however, this assumption is usually violated in practice. If the proportionality assumption holds, HR can be validly with the popular Cox proportional hazards model. When not proportional, the Wilcoxon-Gehan has been proposed to test the hypothesis of no difference. These have been recently generalized to evaluate differences in survival time for more than zero survival differences (the “net survival benefit”). Method: In this thesis, an attempt is made to illustrate the properties of generalized Wilcoxon Gehan tests as proposed by Buyse (2009). We use the concept of net survival benefit to re-analyze the trial by the Gastrointestinal Tumor Study Group (1982) by comparing chemotherapy versus combined chemotherapy and radiation in the treatment of locally unresectable gastric cancer. Survival times in days, for the 45 patients were recorded in each treatment arm. In that trial, a delayed treatment effect was observed, thus the HR is non-proportional. To provide a flexible assessment of the treatment effect, the net survival benefit was computed using datasets simulated under typical scenarios of proportional hazards, such as delayed treatment effect. Results: The generalized Wilcoxon statistic U, favored not adding radiation to chemotherapy, but only for survival up to 12 months. At Δ=0, U (0) = 491. In the simulated data sets, the confidence interval under the null hypothesis U (0) is (-152, 388). The test statistic 491 is outside this interval indicating radiation treatment might be beneficial. At U(12) = 219, it is inside the confidence interval of no treatment effect (-154,268) indicating the benefit of Chemo only is gone after 12 months. Conclusions: The net survival benefit measured via Buyse’s generalized Wilcoxon statistic is a measure of treatment effect that is meaningful whether or not hazards are proportional. The associated statistical test is more powerful than the standard log-rank test when a delayed treatment effect is anticipated.

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24

Quintero-Rincón, Antonio. "Familiaridad en melodías, un estudio introductorio a la memoria musical basándose en la medición del potencial evocado N400." Tesis, 2015. http://hdl.handle.net/10915/46281.

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La cognición y la percepción musical es el estudio científico de las operaciones mentales y neuronales que subyacen al escuchar, crear, moverse y componer música; su interdisciplinariedad incluye métodos de la psicología cognitiva y sensorial, la neurociencia, la musicología, la informática, la teoría musical, las matemáticas, el procesamiento de señales, la genética, la biología y los aspectos socioculturales de la música. El Procesamiento de la música es una actividad mental compleja con un alto componente cognitivo que involucra varias áreas del cerebro, la música cada vez más se utiliza como una forma de investigar la comprensión de las funciones de la mente y el cerebro involucrando temas de la psicológia cognitiva, como la memoria, la atención, la organización perceptual, la categorización y la emoción. Una herramienta poderosa para este fin son los Potenciales Evocados por Eventos (ERP), son mediciones directas de la corteza cerebral generadas en respuesta a estímulos externos, por lo general se usan para medir eventos sensoriales, afectivos y cognitivos. El componente ERP más relacionado con el lenguaje y mejor estudiado es el N400, es una onda con pendiente negativa localizada en la zona central y parietal del cerebro, con una amplitud ligeramente mayor en el hemisferio derecho respecto a del hemisferio izquierdo. El N400 normalmente es visto como una respuesta a violaciones de las expectativas semánticas y su primer uso data de 1980 por M. Kutas y S.A. Hillyard, en este estudio se creo un paradigma que consistió en una lectura con frases fuera de contexto, los resultados mostraron que las palabras que eran más anormales suscitaron un valor positivo en los ERPs, mientras que las palabras semánticamente incorrectas provocaron una onda negativa N400 tardía. Posteriores estudios muestran que la música y el lenguaje se pueden comparar a pesar de que se representan de forma similar, pero a la vez diferente, esto ha llevado a determinar que estos dos dominios pueden transmitir índices fisiológicos, información y conceptos, fortaleciendo cada vez más la unión entre estos dos dominios. La presente tesis forma parte de la primera etapa de un estudio macro donde se pretende determinar si la memoria musical está preservada en personas con deterioro congnitivo leve (DLC) y Alzheimer, en este estudio se plantea la siguiente hipótesis: Conociendo que el potencial evocado N400 es un marcador de deterioro cognitivo, debería esperarse que al evaluar el N400 musical no esté afectado en el DLC y en el Alzheimer, por lo tanto la memoria musical está preservada y puede medirse con el N400. Este estudio está basado en la investigación de Robbin Miranda con la supervisión de Michael T. Ullman, de la Universidad de Georgetown sobre: Doble disociación entre las reglas y la memoria en la música, un estudio de Potenciales Evocados por Eventos, publicado en el Journal Neuroimage. Los resultados en este estudio mostraron una doble disociación, independiente de la formación musical, entre las reglas musicales y la memoria. Además los autores sugieren que las disociaciones de las reglas/memoria, neurocognitivamente se extienden desde el lenguaje a la música, fortaleciendo aún más las similitudes entre los dos dominios. En este estudio se desarrollo un set de estímulos con melodías bien conocidas en Estados Unidos con las siguientes tres condiciones: melodía original (Control), melodía con violación en tono (In-key) y melodía con violación fuera de tono (Out-of-key), esto con el fin de poder estudiar la doble disociación y la dependencia de reglas tanto en la música como en el lenguaje. Teniendo todo esto en cuenta, para la presente tesis se planteo la siguiente hipótesis: Sabiendo que existen melodías bien conocidas es de esperar que si tienen una violación en tono o fuera de tono, sea percibida por el oyente, igualmente si la melodía no es conocida, se espera que la violación fuera de tono sea percibida por el oyente, más no una violación en tono. Para dicho fin, se plantearon dos objetivos: a) Adaptar los estímulos a la cultura musical Argentina, construyendo nuevos estímulos donde fuera necesario y b) Determinar la Familiaridad de las Melodías en sujetos normales. El desarrollo de esta tesis cuenta con un amplio estado del arte y está divido en los siguientes capítulos: dos capítulos iniciales introductorios, necesarios para un tema interdisciplinario como este, uno sobre el Cerebro donde se abordan temas re- ferentes a la actividad eléctrica del cerebro, la neocorteza, el encefalograma, el N400 y las oscilaciones cerebrales; y otro sobre el Procesamiento Cognitivo, donde se abor- dan temas sobre el estado mental, la psicología del sentido común, la conciencia, la persepción auditiva, la atención, la emoción y la memoria. Posteriormente sigue un capítulo donde se explora el tema de la especialización del hemisferio derecho desde el punto de vista de la psicología del arte, tema de mucha controversia y que hasta la fecha sigue abierto. Una vez dados esto temas, en el capítulo sobre el Material y Métodos, se dan temas relacionados con el estímulo, consonancia y disonancia, los cuales son atributos sensoriales cognitivos claves en la percepción musical y el estudio base usado en este trabajo. Finalmente se muestra un experimento con los Resultados y Discusión donde la evaluación de la familiaridad permitió determinar las melodías a usar para el estudio y validar las diferentes condiciones para trabajo futuros.
Esta tesis es un proyecto multidisciplinario en temas de psicología cognitiva y sensorial, neurociencia, música, informática, teoría musical, biología, estadística y procesamiento de señales encefalográficas. Contó con dos directores: el Dr. Marcelo Risk y el Ing. José A. Rapallini. Además del texto, se incluye una muestra de los audios utilizados.

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Bouvrette, Mathieu. "Modèle bayésien pour les prêts investisseurs." Thèse, 2006. http://hdl.handle.net/1866/8193.

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Mothobi, Neo Jack. "Experiences of Physical Sciences teachers when introduced to an electronic expert system." Diss., 2013. http://hdl.handle.net/2263/37313.

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This study outlines the strategies that were employed during the training of Grade 11 Physical Sciences teachers in the use and development of an Electronic Performance Support System (EPSS). The EPSS process involves extended individualised support for teachers through face-to-face training. A purposive sample was utilised and 22 Grade 11 Physical Sciences teachers participated in the study. Teachers’ skills and knowledge before and after the EPSS training process were measured on three measures of satisfaction (course material, the EPSS training process and the trainer’s competencies) and three measures regarding the EPSS (using an EPSS, creating a flowchart and designing an EPSS). A customer satisfaction index questionnaire and retrospective opinionnaire were used to collect data from the participants. Microsoft Excel was used to analyse data collected using the customer satisfaction index questionnaire. Furthermore a Statistical Package for the Social Sciences (SPSS) program was used to analyse data collected using a retrospective opinionnaire. Significant effects were found on all six measures when comparing the skills of teachers before and after attending the EPSS training programme. The results reveal that teachers who participated in the research are satisfied with the use, design and development of an EPSS in education.
Dissertation (MEd)--University of Pretoria, 2013.
gm2014
Science, Mathematics and Technology Education
unrestricted

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Datta, Arya. "Exploring the effects of ECBs unconventional monetary policy announcements on European stock markets." Master's thesis, 2020. http://hdl.handle.net/10400.14/29823.

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This paper conducts an event-study analysis to investigate the relationship between unconventional monetary policy announcements by the ECB and corresponding stock returns in the EMU, furthermore, it also postulates a second hypothesis to ascertain whether this relationship differs for firms listed amongst exchanges in Northern region of the EU name Germany, France and The Netherlands with their Southern Counterparts in the EMU, namely Italy, Portugal and Spain between 2006 and 2015. 10-year Government bond yields for Italy and Germany are used to calculate the surprise coefficient, while the returns are calculated from the return’s indices of the firms on the CAC, PSI, IBEX, DAX, AEX, and MIB30. The significance of the variations of the Returns are tested with Wilcoxon and GRANK tests (Non- Parametric) for AARs and CAARs respectively. The results suggest that there is a relationship between an unconventional monetary policy announcement and stock returns. The results also indicate that this relationship differs for Northern and Southern European firms. The Average Abnormal Returns (AARs) and Cumulative Average Abnormal Returns (CAARs) indicate opposite movement of stock returns in most cases. Finally, an event study analysis is also conducted on 6 portfolios of Europe wide firms segregated through an intersection of firm size and market capitalisation, the results of which do not show enough evidence to claim substantive inference.
Este artigo conduz uma análise de estudo de evento para investigar a relação entre anúncios de política monetária não convencionais do BCE e retornos de ações correspondentes na UEM. Além disso, postula uma segunda hipótese para verificar se essa relação difere para as empresas listadas nas bolsas de valores. Região norte do nome da UE Alemanha, França e Países Baixos, com suas contrapartes do sul na UEM, nomeadamente Itália, Portugal e Espanha entre 2006 e 2015. Os rendimentos dos títulos do governo a 10 anos para Itália e Alemanha são usados para calcular o coeficiente de surpresa, enquanto os retornos são calculados a partir dos índices de retorno das empresas no CAC, PSI, IBEX, DAX, AEX e MIB30. A significância das variações dos retornos é testada com os testes Wilcoxon e GRANK (não paramétricos) para AARs e CAARs, respectivamente. Os resultados sugerem que existe uma relação entre um anúncio de política monetária não convencional e o retorno das ações. Os resultados também indicam que esse relacionamento difere para as empresas do Norte e do sul da Europa. Os retornos anormais médios (AARs) e os retornos anormais médios cumulativos (CAARs) indicam um movimento oposto dos retornos das ações na maioria dos casos. Por fim, também é realizada uma análise de estudo de eventos em 6 carteiras de empresas na Europa, segregadas por uma interseção entre tamanho da empresa e capitalização de mercado, cujos resultados não mostram evidências suficientes para reivindicar inferência substantiva.

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Dissertations / Theses on the topic 'Wilcoxon test'

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