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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.
1

Um estudo de simulação para comparação entre métodos de cálculo do número aproximado de graus de liberdade da estatística F em dados desbalanceados / A simulation study to compare the approximate number calculation methods of degrees of freedom of the F statistic in unbalanced data

Hilário, Andréia Pereira Maria 21 January 2015 (has links)
O desbalanceamento de dados em experimentos está muitas vezes presente em diversas pesquisas nas mais variadas áreas do conhecimento. Embora existam muitas maneiras de análise de tais dados, além de diversos recursos computacionais já implementados em diversos softwares estatísticos, ainda perdura dúvidas entre os pesquisadores a respeito da opção de análise mais eficiente. A literatura fornece ao pesquisador direção na escolha da metodologia de análise a obter maior eficácia nos resultados de sua pesquisa, mas o número elevado de opções pode tornar a escolha difícil. Em se tratando de testes estatísticos, algumas das opções para se trabalhar com dados desbalanceados são os testes t e Wald-F, mas ainda resta ao pesquisador decidir entre as várias opções disponíveis nos pacotes, pois nem sempre as opções padrões são as mais indicadas. No presente trabalho foram realizadas simulações com diferentes cenários experimentais, utilizando-se o delineamento casualizado em blocos com um fator de tratamento em uma situação e o esquema de tratamentos em parcelas subdividas em outra, sendo comparados quatro métodos de cálculo do número aproximado de graus de liberdade (Containment, Residual, Satterthwaite e Kenward-Roger). Verificou-se que o método de Kenward-Roger controla de maneira mais eficiente a taxa de erro tipo I e não é inferior aos outros métodos com respeito ao poder do teste Wald-F. / The data imbalance in experiments is often present in several researches in various fields of knowledge. While there are many ways to analyze these data in addition to various computer resources already implemented in many statistical software, doubt still lingers among researchers about the most efficient analysis option. The literature provides the researcher direction in choosing the analysis methodology to get better in your search results, but the large number of options can make the difficult choice. When it comes to statistical tests, some of the options for working with unbalanced data are the tests t and Wald-F, but there is still the researcher to decide between the various options available in the packages because the defaults are not always the most suitable. This experiment was carried out simulations with different experimental scenarios, using the randomized block design with one factor in a situation treatment and treatment regimen subdivided parcels in another, and compared four methods of calculating the approximate number of degrees of freedom (Containment, Residual, Satterthwaite and Kenward-Roger). It has been found that the method of Kenward-Roger controls more efficiently the type I error rate and is not inferior to other methods with respect to the power of the test Wald-F.
2

Um estudo de simulação para comparação entre métodos de cálculo do número aproximado de graus de liberdade da estatística F em dados desbalanceados / A simulation study to compare the approximate number calculation methods of degrees of freedom of the F statistic in unbalanced data

Andréia Pereira Maria Hilário 21 January 2015 (has links)
O desbalanceamento de dados em experimentos está muitas vezes presente em diversas pesquisas nas mais variadas áreas do conhecimento. Embora existam muitas maneiras de análise de tais dados, além de diversos recursos computacionais já implementados em diversos softwares estatísticos, ainda perdura dúvidas entre os pesquisadores a respeito da opção de análise mais eficiente. A literatura fornece ao pesquisador direção na escolha da metodologia de análise a obter maior eficácia nos resultados de sua pesquisa, mas o número elevado de opções pode tornar a escolha difícil. Em se tratando de testes estatísticos, algumas das opções para se trabalhar com dados desbalanceados são os testes t e Wald-F, mas ainda resta ao pesquisador decidir entre as várias opções disponíveis nos pacotes, pois nem sempre as opções padrões são as mais indicadas. No presente trabalho foram realizadas simulações com diferentes cenários experimentais, utilizando-se o delineamento casualizado em blocos com um fator de tratamento em uma situação e o esquema de tratamentos em parcelas subdividas em outra, sendo comparados quatro métodos de cálculo do número aproximado de graus de liberdade (Containment, Residual, Satterthwaite e Kenward-Roger). Verificou-se que o método de Kenward-Roger controla de maneira mais eficiente a taxa de erro tipo I e não é inferior aos outros métodos com respeito ao poder do teste Wald-F. / The data imbalance in experiments is often present in several researches in various fields of knowledge. While there are many ways to analyze these data in addition to various computer resources already implemented in many statistical software, doubt still lingers among researchers about the most efficient analysis option. The literature provides the researcher direction in choosing the analysis methodology to get better in your search results, but the large number of options can make the difficult choice. When it comes to statistical tests, some of the options for working with unbalanced data are the tests t and Wald-F, but there is still the researcher to decide between the various options available in the packages because the defaults are not always the most suitable. This experiment was carried out simulations with different experimental scenarios, using the randomized block design with one factor in a situation treatment and treatment regimen subdivided parcels in another, and compared four methods of calculating the approximate number of degrees of freedom (Containment, Residual, Satterthwaite and Kenward-Roger). It has been found that the method of Kenward-Roger controls more efficiently the type I error rate and is not inferior to other methods with respect to the power of the test Wald-F.
3

Protesting smoke: a social and political history of Vancouver air pollution

Thiessen, Lee 25 August 2017 (has links)
This thesis examines social and political responses to poor air quality in Vancouver, British Columbia from the 1950s through the early 1970s. Businesses dependent on local markets, the City of Vancouver and medical health officers organized the first civic efforts to strengthen air pollution control in the early 1950s. The provincial government only engaged with the air pollution issue publicly in the early 1960s, and delayed developing clear policy until 1969. Social Credit politicians and representatives of exporting industries generally characterized pollution impacts as aesthetic rather than as harmful to health. This characterization helped justify keeping air policy implementation at the municipal level. Excepting Vancouver, this level proved incapable of dealing with the problem. Public protests of poor air quality increased over time even as visible pollutants decreased. The capitalist state’s imperative to support large corporate interests helps explain the Province’s consistently weak stance on air pollution policy. However, the contradictory imperative of democratic legitimation helps explain policy shifts during the Bennett administration, such as occurred during the public wave of environmental concern in the late 1960s. Vancouver’s consistently stronger stand on air pollution was supported by the local market oriented business community, market shifts to liquid fuels and deindustrialization. Vancouver’s policy experience and federal-provincial political rivalries best explain Greater Vancouver’s retention of industrial air pollution management when the Bennett administration finally asserted control over this pollution source for the rest of the province. / Graduate
4

Metodika zabezpečování optimální přesnosti měření v souladu s metrologickou konfirmací / The Optimal Accuracy of Measurement Assurance in Accordance with Metrological Confirmation

Frank, Petr January 2009 (has links)
This thesis deals with the evaluation of accuracy of measurement and achieving the required accuracy level. This includes global analysis of the uncertainty evaluation, the calibration interval design and the creation of confirmation system. Basis of this work is in identification of all possible problems, which may occur during evaluation of accuracy and achieving the required accuracy level. The analysis is followed by suggested solutions for identified problems. It means namely the selection of probability distribution in case of uncertainty type A, evaluation of degrees of freedom in case of uncertainty type B, nonlinear correlation of input values, evaluation of coverage factor, the choice of method for calibration interval design and the procedure for meeting all metrological confirmation requirements. The last part of the thesis is practical measurement and result evaluation in the field of surge protection devices. This chapter demonstrates conclusions from the syntactical part.

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