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Robustness Against Non-Normality : Evaluating LDA and QDA in Simulated Settings Using Multivariate Non-Normal DistributionsViktor, Gånheim, Isak, Åslund January 2023 (has links)
Evaluating classifiers in controlled settings is essential for empirical applications, as extensive knowledge on model-behaviour is needed for accurate predictions. This thesis investigates robustness against non-normality of two prominent classifiers, LDA and QDA. Through simulation, errors in leave-one-out cross-validation are compared for data generated by different multivariate distributions, also controlling for covariance structures, class separation and sample sizes. Unexpectedly, the classifiers perform better on data generated by heavy-tailed symmetrical distributions than by the normal distribution. Possible explanations are proposed, but the cause remains unknown. There is need for further studies, investigating more settings as well as mathematical properties to verify and understand these results.
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Likelihood-based testing and model selection for hazard functions with unknown change-pointsWilliams, Matthew Richard 03 May 2011 (has links)
The focus of this work is the development of testing procedures for the existence of change-points in parametric hazard models of various types. Hazard functions and the related survival functions are common units of analysis for survival and reliability modeling. We develop a methodology to test for the alternative of a two-piece hazard against a simpler one-piece hazard. The location of the change is unknown and the tests are irregular due to the presence of the change-point only under the alternative hypothesis. Our approach is to consider the profile log-likelihood ratio test statistic as a process with respect to the unknown change-point. We then derive its limiting process and find the supremum distribution of the limiting process to obtain critical values for the test statistic. We first reexamine existing work based on Taylor Series expansions for abrupt changes in exponential data. We generalize these results to include Weibull data with known shape parameter. We then develop new tests for two-piece continuous hazard functions using local asymptotic normality (LAN). Finally we generalize our earlier results for abrupt changes to include covariate information using the LAN techniques. While we focus on the cases of no censoring, simple right censoring, and censoring generated by staggered-entry; our derivations reveal that our framework should apply to much broader censoring scenarios. / Ph. D.
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Regresní a korelační analýza časového vývoje počtu dopravních nehod při přepravě nebezpečných látek ve vybraném regionu. / Regression and correlation analysis of time development of the traffic accidents number at transportation of dangerous substances in a selected region.VÁVRA, Martin January 2012 (has links)
The aim of this thesis was to conduct a statistical survey and the measurement of statistical dependences of time development of the traffic accident rate at transportation of dangerous solid, liquid and gaseous substances, including their total number and also in case of leakage of these substances in a selected region "the Czech Republic". The purpose of the thesis was to verify statistical data, or more precisely, verification of two basic hypotheses H1 and H2, and five sub-hypotheses H11, H12, H13, H14, H15. For these verifications methods of descriptive and mathematical statistics were used, especially regression and correlation analysis in hypothesis H1. To verify hypothesis H2, nonparametric normality test as a technique of mathematical statistics was applied. Verification of hypotheses H1 and their sub-hypotheses H11, H12, H13, H14, H15 enabled to prove linear regression associated with negative correlation within the development of traffic accidents at transportation of dangerous substances in annual units of time (2002 to 2011). Verification of hypothesis H2 enabled to demonstrate normality in distribution of the number of accidents at transportation of dangerous substances within individual months of the monitored period from 2007 to 2011. As benefits of this thesis both the proposal of the sequence of statistical methods for examining the research topic and the application of the mentioned statistical methods to the number of traffic accidents at transportation of dangerous substances can be considered Based on the results of this study, possible follow-up research work may be suggested. A research is proposed which would survey the ways of prevention or other factors leading to negative correlation dependence. Another possibility of follow-up research work could be, for example, statistical surveys and the measurement of statistical dependences in regions of the CR or investigation of the theoretical distribution of the number of traffic accidents at transportation of dangerous substances within a different time unit.
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Využití Psychobiografického modelu péče při práci se seniory / Using of Psychobiographical model of care when working with seniorsSvobodová, Markéta January 2016 (has links)
My dissertation is focused on usage of psychobiographical model of care during working with seniors. The first part of my dissertation is focused on theories, where I explain things such as old age and its age borders, changes in old age and senior's needs, dementia and its forms. We can also find here informations about senior services, social workers and ethic codex. Besides that, my dissertation contains informations about psychobiographical model and everything that is related to it. Second part of my dissertation is focud on concrete usage of the model in Senior House Háje and Senior House Palata for people with eyes dissorder. Keywords Senior, age, Psychobiographical model of care, dementia, normality principle, regression phases, activities of daily living, biographies, individual care plans, memories Therapy.
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Modelling and experimental analysis of frequency dependent MIMO channelsGarcía Ariza, Alexis Paolo 04 December 2009 (has links)
La integración de tecnologías de ulta-wideband, radio-cognitiva y MIMO representa una herramienta podersoa para mejorar la eficiencia espectral de los sistemas de comunicación inalámbricos. En esta dirección, nuevas estrategias para el modelado de canales MIMO y su caracterización se hacen necesarias si se desea investigar cómo la frecuencia central y el acho de banda afectan el desempeño de los sistemas MIMO. Investigaciones preliminares han enfocado menos atención en cómo estos parámetros afectan las características del canal MIMO. Se presenta una caracterización del canal MIMO en función de la frecuencia, abondándose puntos de vista experimentales y teóricos. Los problemas indicados tratan cinco áreas principales: medidas, post-procesado de datos, generación sintética del canal, estadística multivariable para datos y modelado del canal.
Se ha diseñado y validado un sistema de medida basado en un analizador vectorial de redes y se han ejecutado medidas entre 2 y 12 GHz en condiciones estáticas, tanto en línea de vista como no línea de vista. Se ha propuesto y validado un procedimiento confiable para post-procesado, generación sintética de canal y análisis experimental basado en medidas en el dominio de frecuencia. El procedimiento experimental se ha focalizado en matrices de transferencia del canal para casos no selectivos en frecuencia, estimándose además las matrices complejas de covarianza, aplicándose la factorización de Cholesky sobre ls CCM y obteniéndose finalmente matrices de coloreado del sistema. Se presenta un procedimiento de corrección para generación sintética del canal aplicado a casos MIMO de grandes dimensiones y cuando la CCM es indefinida. Este CP permite la factorización de Cholesky y de dichas CCM. Las características multivariables de los datos experimentales han sido investigadas, realizándose un test de normalidad compleja multivariable. / García Ariza, AP. (2009). Modelling and experimental analysis of frequency dependent MIMO channels [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/6563 / Palancia
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Simulating Statistical Power Curves with the Bootstrap and Robust EstimationHerrington, Richard S. 08 1900 (has links)
Power and effect size analysis are important methods in the psychological sciences. It is well known that classical statistical tests are not robust with respect to power and type II error. However, relatively little attention has been paid in the psychological literature to the effect that non-normality and outliers have on the power of a given statistical test (Wilcox, 1998). Robust measures of location exist that provide much more powerful tests of statistical hypotheses, but their usefulness in power estimation for sample size selection, with real data, is largely unknown. Furthermore, practical approaches to power planning (Cohen, 1988) usually focus on normal theory settings and in general do not make available nonparametric approaches to power and effect size estimation. Beran (1986) proved that it is possible to nonparametrically estimate power for a given statistical test using bootstrap methods (Efron, 1993). However, this method is not widely known or utilized in data analysis settings. This research study examined the practical importance of combining robust measures of location with nonparametric power analysis. Simulation and analysis of real world data sets are used. The present study found that: 1) bootstrap confidence intervals using Mestimators gave shorter confidence intervals than the normal theory counterpart whenever the data had heavy tailed distributions; 2) bootstrap empirical power is higher for Mestimators than the normal theory counterpart when the data had heavy tailed distributions; 3) the smoothed bootstrap controls type I error rate (less than 6%) under the null hypothesis for small sample sizes; and 4) Robust effect sizes can be used in conjuction with Cohen's (1988) power tables to get more realistic sample sizes given that the data distribution has heavy tails.
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Rätten till ett liv som andra : Föreställningar om funktionalitet, normalitet och sårbarhet i LSS (Lagen om stöd och service till vissa funktionshindrade)Ullgren, Kristina January 2016 (has links)
This thesis analyzes the concept of ”funktionalitet” (the dis/ability divide), normality and vulnerability in the Swedish Law on Support and Service to Certain Disabled People (Lagen om stöd och service till vissa funktionshindrade – LSS). LSS is the main rights law for people with disabilities and was groundbreaking when it came, but has since its legislation not been developed any further. Recent debate has shown that the law is not implemented according to its intentions. Through the use of discourse analysis and the theoretical perspectives ableism, intersectionality and vulnerability this thesis investigates the understanding of ”funktionalitet” in the legislation and the official government inquiry (SOU 1991:46) that submitted a proposal for the law in 1991. The main conclusions of the analysis point toward a conception of ”funktionalitet” as both depending on the power structure of ableism and as a diversity in humanity. The position as a person with disability is portrayed as a special (or pathogenic) vulnerability in order to claim special rights. Moreover the thesis briefly discusses how the position as a person with disabilities is denied other identificatory categories such as a person with a gender identity, sexuality and/or being a parent. These are topics for further research.
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Estimating rigid motion in sparse sequential dynamic imaging: with application to nanoscale fluorescence microscopyHartmann, Alexander 22 April 2016 (has links)
No description available.
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Avaliação da videolaringoscopia de alta velocidade de sujeitos normais / Evaluation of high-speed videolaryngoscopy in normal subjectsTsutsumi, Monike 30 January 2015 (has links)
Estudos utilizando imagens laríngeas de sujeitos normais captadas por videolaringoscopia de alta velocidade revelam o uso de diversas ferramentas e métricas em diferentes populações. No entanto, é evidente a escassez de normatizações operacionais e de parâmetros vocais de referência. Os objetivos desse estudo foram obter parâmetros da dinâmica vocal utilizando ferramentas computacionais de uso corrente pelo Grupo de Pesquisa em Engenharia Médica (GPEM - CNPq) e caracterizar o padrão vibratório das pregas vocais de sujeitos normais por meio das ondas da área glótica e quimografia de alta velocidade do utilizando Videolaringoscopia de alta velocidade. Metodologia: A partir de imagens laríngeas captadas pela videolaringoscopia de alta velocidade foram extraídos os parâmetros quantitativos: i) tempos de fases e período total do ciclo vibratório das pregas vocais das ondas da área glótica, ii) tempos de fases e período total do ciclo vibratório das pregas vocais da quimografia de alta velocidade, iii) coeficientes (de abertura, de fechamento e de velocidade). Além disso, foram analisados os parâmetros qualitativos das ondas da área glótica e da quimografia de alta velocidade de acordo com a aplicação de protocolos elaborados para classificação de padrões visuais. Resultados: Das ondas da área glótica foram obtidos os valores médios, em milissegundos, de fase fechada: feminino=0.83 e masculino= 2.47; de abertura: feminino= 2.43 e masculino= 2.95; de fechamento: feminino=2.08 e masculino= 2.53; aberta: feminino= 6.15 e masculino= 6.18, período total do ciclo vibratório: feminino=6.98 e masculino= 8.65; coeficientes: de fechamento: feminino=0.14 e masculino=0.29, de abertura: feminino=0.85 e masculino=0.70, de velocidade: feminino=1.16 e masculino=1.19, além de 73% dos traçados apresentarem sinal periódico. Quanto à quimografia de alta velocidade os parâmetros quantitativos obtidos foram: fase fechada: feminino=1.75 e masculino=3.32, de abertura: feminino= 1.47 e masculino= 2.32; de fechamento: feminino= 1.51 e masculino= 2.22; aberta: feminino= 2.91 e masculino= 4.56, e período total do ciclo vibratório: feminino= 4.67 e masculino= 7.89. Os coeficientes obtidos foram: de fechamento: feminino= 0.37 e masculino= 0.42.; de abertura: feminino= 0.62 e masculino= 0.57; e de velocidade: feminino= 1.02 e masculino= 1.12. 59% de simetria em amplitude e 54% de assimetria de fase foram encontrados no traçado da quimografia de ata velocidade de sujeitos normais. Conclusão: A partir do uso de ferramentas computacionais específicas para analisar imagens laríngeas da videolaringoscopia de alta velocidade foi possível obter parâmetros quantitativos e qualitativos das ondas da área glótica e quimografia de alta velocidade de sujeitos normais e obter dados de referência quanto à normalidade para futuros estudos. / Several studies using laryngeal images from high-speed videolaryngoscopy of normal subjects reveals the diversity of tools and metrics used for different population. However, shortage of operational standardization and references of vocal fold parameters are evident. The main objectives of this study were to obtain parameters of vocal dynamics using computational tools of Medical Engineering Research Group (GPEM - CNPq) and to characterize the vocal fold\'s vibration pattern of normal subjects using glottal area waveforms and high-speed kymography. Methods: From laryngeal images of high-speed videolaryngoscopy we extracted the following quantitative parameters: i) phase time of glottal area waveforms, ii) phase time of vibratory cicle\'s total period, iii) quocients of high-speed kymography. Furthermore, qualitative parameters of glottal area waveform were analyzed according to visual pattern protocol. Results: Media values of glottal area waveforms, in milliseconds, of closed phase: female=0.83 and male= 2.47; opening phase: female= 2.43 and male= 2.95; closing phase: female= 2.08 and male= 2.53; opened phase: female=6.15 and male= 6.18, vibratory cicle of total period: female= 6.98 and male= 8.65, closing quotient: female= 0.14 and male= 0.29; opening quotient: female= 0.85 and male= 0.70; speed quotient: female= 1.16 and male= 1.19, besides 73% showed periodic signal. As the high- speed kymography the quantitative parameters obtained were: closed phase: female= 1.75 and male= 3.32; opening phase: female= 1.47 and male= 2.32; closing phase: female= 1.51 and male= 2.22; opened phase: female= 2.91 and male= 4.56, and vibratory cicie of total period: female= 4.67 and male= 7.89. The quotients obtained were: closing quotient: female= 0.37and male= 0.42; opening quotient: female= 0.62 and male= 0.57; speed quotient: female= 1.02 and male= 1.12. 59% amplitude symmetry and 54% phase asymmetry were obtained in the high- speed kymography of normal subjects. Conclusion: using specific computational tools to analyse high-speed laryngeal images we obtained quantitative and qualitative parameters of glottal area waveforms and high-speed kymography that can be used as a standard reference data for normal subjects.
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Le droit de la procréation en France et en Allemagne : étude sur la normalisation de la vie / Reproductive rights in France and Germany : study on the normalization of lifeMarguet, Laurie 05 December 2018 (has links)
Le traitement juridique de la procréation est volontiers présenté, en France et en Allemagne, comme servant à limiter les dérives, à garantir les valeurs fondatrices de la société tout en assurant la protection du corps humain, de la personne et de la dignité humaine. Cet encadrement apparaît comme nécessaire pour lutter contre les abus que la consécration d’une liberté procréative rendrait possibles. Mais est-ce réellement le principe de protection de la vie et de la personne qui constitue le paradigme principal du droit de la procréation ? En prenant notamment pour cadrage théorique les réflexions de Michel Foucault et de Giorgi Agamben sur la biopolitique, il apparaît que ce n’est pas la protection de la vie biologique, zoe, la vie nue, c'est-à-dire le seul fait de vivre, commun à toutes les espèces vivantes, que l’État entend protéger mais seulement certaines de ces formes : la vie bonne - c'est-à-dire la vie bonne, celle qui est axiologiquement et politiquement significative. Les diverses réglementations du champ procréatif - contraception, avortement, procréation médicalement assistée et gestation pour autrui - entendent mettre en œuvre des processus de normalisation de la vie, particulièrement visibles en ce qui concerne la famille et le handicap physique et mental. / How Law addresses procreation is often presented, both in France and Germany, as a way to limit abuses, to guarantee founding values of the society while ensuring at the same time the protection of the human body, the human person and its personal dignity.This legal framework seems to be necessary to prevent any abuse that may arise from procreative freedoms’ enshrinement.The question is thus the following : Is this principle of protection really constitutive of the main paradigm of reproductive rights ? Is the protection of life and of the human person the base of this paradigm ? Taking Michel Foucault’s and Giorgi Agamben’s work on biopolitic as a theoretical frame, it seems that the State does not intend to protect zoe (biological life), the « bare life », i.e. the simple fact of living, encompassing all living species.It appears that the State aims to only protect some forms of life : the « good » life, i.e. the life which is meaningful both axiologically and politically.Via various regulations on procreation - birth control, abortion, medically-assisted procreation or surrogate motherhood - the State implement processes that lead to normalize the life per se. These processus are especially visible when relate to the family as well as physical or mental disability.
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