To increase real estate values, developers often apply designs on the land. In the case of a single family housing development, the designs are applied to the unit of subdivisions. In this study, the designs are defined as “value creation concepts,” which increase housing values at the subdivision level. The value creation concepts are classified into five categories – the sense of arrival, product mix, walkability, circulation system, and amenity. This cross-sectional study focuses on exploring the effects of value creation concepts in the subdivision. Two methodologies – the Hedonic Price Model (HPM) and the Hierarchical Linear Model (HLM) – are used to test whether or not the value creation concepts would increase or decrease single family housing values. The study sample is composed of 6,562 single family houses nested in 85 subdivisions in College Station, Texas. Data are composed of two levels: the housing level and the subdivision level. The scores of the sense of arrival were provided by sixtyone graduate students at Texas A&M University using photograph evaluations. Most structural variables were obtained from the Brazos County Appraisal District, and physical environmental variables were objectively measured using the Geographical Information System. In the both models, sense of arrival, greenway connectivity, sidewalk connectivity, and median length of cul-de-sac variables have positive effects on single family housing values while phased project, the number of accessible entrances, street density, single family density, and median length of block variables have negative effects on single family housing values. At the housing level, several structural variables (e.g. bathrooms, attached garage, porches, etc), attached to a golf course, sports facilities, network distance from the nearest elementary school, population density, and personal variables (i.e., tenure, workable age, employment) were significant (p<.05) predictors of single family housing value. Findings support that the value creation concepts have effects on increasing housing values at the subdivision level, which would provide thoughtful insights for developers in residential areas. In addition, the HLM can be used as the complement of the HPM by controlling interaction terms between housing variables and subdivision variables, or among the subdivision variables themselves.

In an experiment to understand colon carcinogenesis, all animals were exposed to a carcinogen while half the animals were also exposed to radiation. Spatially, we measured the existence of aberrant crypt foci (ACF), namely morphologically changed colonic crypts that are known to be precursors of colon cancer development. The biological question of interest is whether the locations of these ACFs are spatially correlated: if so, this indicates that damage to the colon due to carcinogens and radiation is localized. Statistically, the data take the form of binary outcomes (corresponding to the existence of an ACF) on a regular grid. We develop score??type methods based upon the Matern and conditionally autoregression (CAR) correlation models to test for the spatial correlation in such data, while allowing for nonstationarity. Because of a technical peculiarity of the score??type test, we also develop robust versions of the method. The methods are compared to a generalization of Moran??s test for continuous outcomes, and are shown via simulation to have the potential for increased power. When applied to our data, the methods indicate the existence of spatial correlation, and hence indicate localization of damage. Assuming that there are correlations in the locations of the ACF, the questions are how great are these correlations, and whether the correlation structures di?er when an animal is exposed to radiation. To understand the extent of the correlation, we cast the problem as a spatial binary regression, where binary responses arise from an underlying Gaussian latent process. We model these marginal probabilities of ACF semiparametrically, using ?xed-knot penalized regression splines and single-index models. We ?t the models using pairwise pseudolikelihood methods. Assuming that the underlying latent process is strongly mixing, known to be the case for many Gaussian processes, we prove asymptotic normality of the methods. The penalized regression splines have penalty parameters that must converge to zero asymptotically: we derive rates for these parameters that do and do not lead to an asymptotic bias, and we derive the optimal rate of convergence for them. Finally, we apply the methods to the data from our experiment.

This thesis develops and evaluates statistical methods for different types of genetic analyses, including quantitative trait loci (QTL) analysis, genome-wide association study (GWAS), and genomic evaluation. The main contribution of the thesis is to provide novel insights in modeling genetic variance, especially via random effects models. In variance component QTL analysis, a full likelihood model accounting for uncertainty in the identity-by-descent (IBD) matrix was developed. It was found to be able to correctly adjust the bias in genetic variance component estimation and gain power in QTL mapping in terms of precision.  Double hierarchical generalized linear models, and a non-iterative simplified version, were implemented and applied to fit data of an entire genome. These whole genome models were shown to have good performance in both QTL mapping and genomic prediction. A re-analysis of a publicly available GWAS data set identified significant loci in Arabidopsis that control phenotypic variance instead of mean, which validated the idea of variance-controlling genes.  The works in the thesis are accompanied by R packages available online, including a general statistical tool for fitting random effects models (hglm), an efficient generalized ridge regression for high-dimensional data (bigRR), a double-layer mixed model for genomic data analysis (iQTL), a stochastic IBD matrix calculator (MCIBD), a computational interface for QTL mapping (qtl.outbred), and a GWAS analysis tool for mapping variance-controlling loci (vGWAS).

Due to the inherently hierarchical nature of many natural phenomena, data collected rests in nested entities. As an example, students are nested in schools, school are nested in districts, districts are nested in counties, and counties are nested within states. Multilevel models provide a statistical framework for investigating and drawing conclusions regarding the influence of factors at differing hierarchical levels of analysis. The work in this paper serves as an introduction to multilevel models and their comparison to Ordinary Least Squares (OLS) regression. We overview three basic model structures: variable intercept model, variable slope model, and hierarchical linear model and illustrate each model with an example of student data. Then, we contrast the three multilevel models with the OLS model and present a method for producing confidence intervals for the regression coefficients. / text

Receiver operating characteristic (ROC) curves have been widely used in evaluation of the goodness of the diagnostic method in many study fields, such as disease diagnosis in medicine. The area under the ROC curve (AUC) naturally became one of the most used variables in gauging the goodness of the diagnosis (Mossman, Somoza 1991). Since medical diagnosis often is not dichotomous, the ROC curve and AUC need to be generalized to a multi-dimensional case. The generalization of AUC to multi-class case has been studied by many researchers in the past decade. Most recently, Nakas & Yiannoutsos (2004) considered the ordered d classes ROC analysis by only considering the sensitivities of each class. Hence, their dimension is only d. Cha (2005) considered more types of mis-classification in the ordered multiple-class case, but reduced the dimension of Ferri, at.el. from d(d-1) to 2(d-1). In this dissertation we are trying to adjust and calculate the VUS for an ordered multipleclass with Cha’s 2(d-1)-dimension method. Our methodology of finding the VUS is introduced. We present the method of adjusting and calculating VUS and their statistical inferences for the 2(d-1)-dimension. Some simulation results are included and a real example will be presented. Intellectual outcomes in pediatric brain-tumor patients were investigated in a prospective longitudinal study. The Standard-Binet Intelligence Scale-Fourth Edition (SB-IV) Standard Age Score (SAS) and Composite intelligence quotient (IQ) score are examined as cognitive outcomes in pediatric brain-tumor patients. Treatment factors, patient factors and time since diagnosis are taken into account as the risk factors. Hierarchical linear/quadratic models and Gompertz based hierarchical nonlinear growth models were applied to build linear and nonlinear longitudinal curves. We use PRESS and Volume Under the Surface (VUS) as the criterions to compare these two methods. Some model interpretations are presented in this dissertation.

本研究旨在探討猝睡症患者生活品質受症狀變化及神經認知功能改變的影響情況，以及不同層次影響因素對患者生活品質的初始狀態及後續變化軌跡的影響效果。 本研究於北部一所醫學中心睡眠障礙科及兒童心智科募集確診為猝睡症之患者，經同意後進行為期五年的長期研究，募集總人數168人，完成五年資料收集人數85人。本研究使用睡眠多項檢驗（polysomnography, PSG）、多段入睡測試（multiple sleep latency test, MSLT）、人類白血球抗原檢驗（human leukocyte antigen, HLA）為基本檢驗工具，以電腦化第二版康氏持續注意力測驗（Continuous Performance Test- II）及威斯康辛卡片分類測驗（Wisconsin Card Sorting Test, WCST）為檢測神經認知功能之工具，以自填艾普渥斯嗜睡程度量表（Epworth sleepiness scale, ESS）、史丹佛睡眠問卷（Stanford sleep inventory, SSI）及簡式生活品質量表（short from-36 items of health related quality of life, SF-36）做為症狀嚴重度及生活品質的依據。資料分析以描述統計及階層線性模式（hierarchical linear models , HLM）統計方法進行。主要結果如下： 一、 猝睡症患者生活品質分為生理與心理兩個層面，患者生理層面在五年期間維持相對穩定沒有顯著變化；心理層面中之不同向度則有不同變化趨勢，心理健康與活力向度隨時間有逐漸提高的趨勢，患者此二向度生活品質接受治療後有穩定上升的趨勢，而社會功能及情緒角色限制則呈現二次方曲線變化，以及呈現先增後減的發展軌跡，患者此二向度接受治療後顯著上升，第三年後有逐年下降的趨勢。 二、 患者嗜睡程度及猝倒嚴重度變化隨時間有顯著成長軌跡，呈二次方曲線發展，轉折點在第三年，接受治療前三年症狀呈現穩定降低的軌跡，但自第三年起逐年增加，此結果與藥物治療初期症狀獲得顯著改善，後期改善幅度相對減少，及藥物效果具有關聯。 三、 個體間層次變項僅疾病持續時間、HLA對患者生活品質具顯著解釋力，其中疾病持續時間越長，患者可能發展因應症狀之策略，從而降低疾病對生活品質之衝擊。而HLA則對症狀有不同影響，HLA陽性患者初始嗜睡程度較陰性者為低，且接受治療後改善效果較陰性者顯著，猝倒嚴重度起始值較陰性者高，且接受治療後的趕善幅度較陰性者小。 四、 疾病嚴重度變化對生活品質具顯著影響，完整模式分析中，時間主效應未達顯著，但可由症狀變化及神經認知功能改變進行更佳的解釋。嗜睡程度變化僅對身體疼痛向度變化不具有解釋力外，對其餘七個向度均具顯著影響；猝倒影響層面不及嗜睡程度，但亦可解釋生理量表、生理角色限制、心理量表、心理健康、情緒角色限制、活力等向度上的變化。 五、 神經認知功能改變與否對患者生活品質具有加成效果，分析顯示患者神經認知功能改善時，其生活品質提升速率較未改善者高，影響較顯著的包括注意力、警覺度及概念反應，此結果與下視丘泌素參與的維持注意力及前額葉功能有關。 本研究依據分析結果提出猝睡症患者生活品質受嗜睡症狀及猝倒嚴重度改變直接影響，同時受人類白血球抗原屬性及神經認知功能改變調節之假設模型，作為未來研究參考依據。並根據研究結果與限制，提出對臨床實務的應用與心理介入的建議，並對未來提升猝睡症患者生活品質相關研究提供建議。 / The current study aims to: (1) examine the change of eight domains of quality of life in narcoleptics within five years, (2) investigate the impact of the change of symptom severity on different dimension of quality of life, as well as the influence associated with the change of neuro-cognitive function. There were 168 participants recruited from a medical center in northern Taiwan. 85 of them completed the 5-year annual follow-up data collection. During the follow-ups, polysomnography (PSG), multiple sleep latency test (MSLT) and human leukocyte antigen (HLA) test were conducted. Computerized neuropsychological tests of Conners’ Continuous Performance Test- II (CPT-II) and Wisconsin Card Sorting Test (WCST) were also administered to obtain attention and executive function data. The short from-36 items of health related quality of life (SF-36), Stanford sleep inventory (SSI) and Epworth sleepiness scale were applied to assess quality of life and symptom severity. Descriptive statistics and hierarchical linear models were applied for data analysis. The main results were: 1. The quality of life was divided into physical and psychological domains. The physical domain kept relatively stable during the 5-year follow up as opposed to the psychological domain. In psychological domain, the vitality and psychological health showed increasing tendency overtime. However, the social function and role functioning-emotion increased during the first 3 years then declined afterward. 2. The symptom severity also showed a tendency corresponded to quadratic curve. The daytime sleepiness together with cataplexy severity reduced immediately after treatment but rose after the third year. 3. The variables of individual characteristics that showed significant impact on quality of life were disease duration and HLA type. The longer the duration, the better quality of life one had. Positive HLA typing seemed to be a protective factor on severity of sleepiness. It also predicted better treatment outcomes, but worsen the severity of cataplexy and treatment effects. 4. The symptom severity could be a good explanation as a variable of quality of life. The daytime sleepiness altered all domain of SF-36 expect body pain. Cataplexy affected only psychological domain of SF-36. 5. The neuro-cognitive function was also found to affect quality of life. Those who improved in attention and executive function test got greater improvement on SF-36 as well. The vigilance on CPT-II and conceptualized response on WCST had most significant impact. I proposed a model of change of quality of life in patients with narcolepsy based on the results obtained. Several suggestions were also proposed for clinical and psychological intervention for narcolepsy to improve their quality of life.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Reliable growth data from trees are very important in the context of forest management. Tree-characteristics such as architecture and competition are associated with diameter growth. Previous studies analyzing tree growth changes have indicated that these variables can describe these effects more effectively. However, the precise role of these effects in the growth modeling of tropical trees needs to be studied further to discuss more effectively the actual forest management practices. Here, we reconstructed the periodic annual basal area increment (IPAg) of four long-lived timber species from the Amazon forest: Cedro (Cedrela odorata); Cerejeira (Amburana cearensis); Copaíba (Copaifera paupera) e Mogno (Swietenia macrophylla) aiming to explain the IPAg variation by developing a individua-tree growth model using the following potential predictors: tree size, morphometric data, competition; crown position and liana load. The model was fitted using a Gamma distribution in the context of Generalized Linear Models. The statistics criteria and residual distributions showed that growth model was adequate to adjust the observed IPAg data and revealed some dendrometric variables that were involved into the effects that lead the observed variation in IPAg, presenting a broad range of the observed data in situations were growth is complex and variable between species. Trees sampled in good site conditions - expressed as a good crown exposure to light, and therefore low competition - presented higher growth rates than trees sampled under high competition from neighboring trees. Besides, the variables Liana load, for Cedrela, the crown diameter and the Hegyi competition index was demonstrated to be highly influential predictive variable. Also, trees sampled in densities greater than 25 m2.ha-1 had their IPAg% significantly reduced. In the context of basal area increment yield by the space occupied in the forest (crown efficiency) the species presented mostly efficiency when growth in dominant position with thin and long crown (crown formal). Among the species, Cedrela odorata was the most efficient in growth. This behavior reinforces the importance of release trees to obtain better crown exposure. / Dados confiáveis de crescimento de árvores são muito importantes no contexto do manejo florestal. Características próprias da árvore como a arquitetura e a competição estão associadas diretamente com o crescimento em diâmetro e altura. Estudos anteriores indicaram que essas variáveis podem descrever a variação do incremento. No entanto, o efeito dessas variáveis na modelagem do crescimento de árvores tropicais precisa ser mais bem estudado, para discutir efetivamente as praticas de manejo florestal atuais. Portanto, nessa pesquisa reconstruiu-se o incremento periódico anual em área basal (IPAg) de quatro espécies de árvores madeiráveis de vida longa da Amazônia: Cedro (Cedrela odorata); Cerejeira (Amburana cearensis); Copaíba (Copaifera paupera) e Mogno (Swietenia macrophylla) com o objetivo de explicar a variação de IPAg, propondo um modelo de crescimento tipo de árvore individual utilizando os seguintes preditores potenciais: tamanho e morfometria da árvore; o status competitivo; a posição social e a carga de lianas na copa. O modelo foi ajustado considerando a distribuição de probabilidade Gama no contexto de Modelo Linear Generalizado. Em base a critérios estatísticos e avaliação residual, o modelo de crescimento demonstrou ser adequado para explicar a variação de IPAg e revelou variáveis dendrométricas que englobam grande parte dos efeitos que moldaram a variação observada do IPAg, apresentando boa abrangência dos dados observados em situações onde o crescimento é complexo e variado entre as espécies. As árvores quando amostradas em boas condições de sítio, expressado por boa exposição da copa à luz solar e, portanto, pouca competição, apresentaram as maiores taxas de IPAg, no período avaliado, do que aquelas encontradas sob forte competição por árvores vizinhas. Além disso, as variáveis carga de lianas na copa, para Cedrela, o diâmetro de copa e o status competitivo de Hegyi influenciaram de forma significativa o IPAg. Árvores amostradas em densidade maior do que 25 m2.ha-1 mostraram queda significativa do IPAg%. No contexto de incremento em área basal por área ocupada na floresta (eficiência da copa), todas as quatro espécies mostraram-se mais eficientes quando em melhor posição social e quando com copas estreitas e longas (formal de copa pequeno). Entre as espécies a Cedrela odorata foi a mais eficiente no crescimento, comportamento que reforça a importância da liberação das árvores o que proporcionaria melhor exposição da copa à luz solar.

Made available in DSpace on 2015-03-26T13:32:10Z (GMT). No. of bitstreams: 1 texto completo.pdf: 888452 bytes, checksum: 8d80ca0e2b7ce975cc072fb5b159da92 (MD5) Previous issue date: 2011-02-14 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / This study aims to verify the effect of restrictions in the data set as the minimum number of weighings per animal on the nonlinear models parameters estimation of growth curves for sheep crossed. It was used data on average weight for age and individual weight for age of 74 crossbred, from the Texel and Santa Inês cross grown in the northeastern region in order to estimate the growth curves parameters. It was used seven data structures with restriction of at least 5, 6, 7, 8, 9 or 10 weights per animal and without restriction. Brody, von Bertalanffy, Logistic and Gompertz models were fitted to weight-age data. The quality of the models adjustment according to the restrictions on data was evaluated by the coefficient of determination (R2 aj), Mean prediction error (MPE) and Mean Square Residual (MSR). Usual diagnostic techniques, such as leverage points, aberrant points and influential measures were used to identify atypical points. All the structures presented estimates for mature weight, maturity index, instantaneous growth rate, relative instantaneous growth rate and inflection point very close and consistent to the ones presented by the literature. Once the values of R2 aj, EPM and QMR were close, it can be concluded that with or without restriction, the quality of fit was very similar, then the use of data with large variation in the number of weighings per animal (4-13) did not compromise the quality of the models adjustments. It can be concluded also that it is possible to obtain good fit, even for data set with few animals, since they present with a greater frequency. / O objetivo deste trabalho foi verificar o efeito de restrições no conjunto de dados quanto ao número mínimo de pesagens por animal sobre a estimação de parâmetros de modelos não-lineares de curvas de crescimento para ovinos cruzados. Utilizou-se dados de pesos médios por idade e pesos individuais por idade de 74 animais mestiços, do cruzamento Texel x Santa Inês criados na região nordeste para estimar os parâmetros das curvas de crescimento. Foram utilizadas 7 estruturas de dados com restrição de no mínimo 5, 6, 7, 8, 9 ou 10 pesagens por animal e sem restrição. Os modelos Brody, von Bertalanffy, Logístico e Gompertz foram ajustados aos dados de peso-idade. A qualidade de ajuste dos modelos em função da restrição nos dados foi avaliada pelo coeficiente de determinação ajustado (R2 aj), Erro de Predição Médio (EPM) e o Quadrado Médio do Resíduo (QMR). Técnicas usuais de diagnóstico, como pontos de alavanca, pontos aberrantes e medidas influentes foram utilizadas para a identificação de pontos atípicos. Todas as estruturas de dados apresentaram estimativas para o peso adulto, taxa de maturidade, taxa de crescimento instantâneo, taxa de crescimento instantâneo relativo e ponto de inflexão muito próximos e condizentes com a literatura. Como os valores de R2 aj, EPM e QMR foram próximos, conclui-se que com ou sem restrição, a qualidade de ajuste foi muito similar. Portanto, a utilização de dados com grande variação no número de pesagens por animal (de 4 a 13 pesagens) não comprometeu a qualidade de ajuste dos modelos. Pode-se concluir, também, que é possível obter boa qualidade de ajuste mesmo para conjunto de dados com poucos animais, desde que estes apresentem maior freqüência de pesagens.

Nos travaux se sont articulés autour du problème de recouvrement temporel rencontré lors de l'estimation des potentiels évoqués. Il constitue, plus particulièrement, une limitation majeure pour l'estimation des potentiels évoqués par les fixations ou saccades oculaires lors d'une expérience en enregistrement conjoint EEG et oculométrie. En effet, la méthode habituellement utilisée pour estimer ces potentiels évoqués, la méthode par simple moyennage du signal synchronisé sur l'évènement d'intérêt, suppose qu'il y a un seul potentiel évoqué par essai. Or selon les intervalles inter-stimuli, cette hypothèse n'est pas toujours vérifiée. Ceci est d'autant plus vrai dans le contexte des potentiels évoqués par fixations ou saccades oculaires, les intervalles entre ceux-ci n'étant pas contrôlés par l'expérimentateur et pouvant être plus courts que les latences des potentiels d'intérêt. Le fait que cette hypothèse ne soit pas vérifiée donne une estimation biaisée du potentiel évoqué du fait des recouvrements entre les potentiels évoqués.Nous avons donc utilisé le Modèle Linéaire Général (GLM), méthode de régression linéaire bien connue, pour estimer les potentiels évoqués par les mouvements oculaires afin de répondre à ce problème de recouvrement. Tout d'abord, nous avons introduit, dans ce modèle, un terme de régularisation au sens de Tikhonov dans l'optique d'améliorer le rapport signal sur bruit de l'estimation pour un faible nombre d'essais. Nous avons ensuite comparé le GLM à l'algorithme ADJAR dans un contexte d'enregistrement conjoint EEG et oculométrie lors d'une tâche d'exploration visuelle de scènes naturelles. L'algorithme ADJAR ("ADJAcent Response") est un algorithme classique d'estimation itérative des recouvrements temporels développé en 1993 par M. Woldorff. Les résultats ont montré que le GLM était un modèle plus flexible et robuste que l'algorithme ADJAR pour l'estimation des potentiels évoqués par les fixations oculaires. Puis, deux configurations du GLM ont été comparées pour l'estimation du potentiel évoqué à l'apparition du stimulus et du potentiel évoqué par les fixations au début de l'exploration. Toutes deux prenaient en compte les recouvrements entre potentiels évoqués mais l'une distinguait également le potentiel évoqué par la première fixation de l'exploration du potentiel évoqué par les fixations suivantes. Il est apparu que le choix de la configuration du GLM était un compromis entre la qualité de l'estimation des potentiels et les hypothèses émises sur les processus cognitifs sous-jacents.Enfin, nous avons conduit de bout en bout une expérience d'envergure en enregistrement conjoint EEG et oculométrie portant sur l'exploration des expressions faciales émotionnelles naturelles statiques et dynamiques. Nous avons présenté les premiers résultats pour la modalité statique. Après avoir discuté de la méthode d'estimation des potentiels évoqués selon l'impact des mouvements oculaires sur leur fenêtre de latence, nous avons étudié l'effet du type d'émotion. Nous avons trouvé des modulations du potentiel différentiel EPN (Early Posterior Negativity), entre 230 et 350 ms après l'apparition du stimulus et du potentiel LPP (Late Positivity Potential), entre 400 et 600 ms après l'apparition du stimulus. Nous avons également observé des variations du potentiel évoqué par les fixations oculaires. Pour le potentiel LPP, qui est un marqueur de la reconnaissance consciente de l'émotion, nous avons montré qu'il était important de dissocier l'information qui est immédiatement encodée à l'apparition du stimulus émotionnel, de celle qui est apportée à l'issue de la première fixation. Cela met en évidence un motif d'activation différencié pour les stimuli émotionnels à valence négative ou à valence positive. Cette différenciation est en accord avec l'hypothèse d'un traitement plus rapide des stimuli émotionnels à valence négative que des stimuli émotionnels à valence positive. / Our research focuses on the issue of overlapping for evoked potential estimation. More specifically, this issue is a significant limitation for Eye-Fixation Related Potentials and Eye-Saccade Related Potentials estimations during a joint EEG and eye-tracking recording. Indeed, the usual estimation, by averaging the signal time-locked to the event of interest, is based on the assumption that a single evoked potential occurs during a trial. However, depending on the inter-stimulus intervals, this assumption is not always verified. This is especially the case in the context of Eye-Fixation Related Potentials and Eye-Saccade Related Potentials, given the fact that the intervals between fixations (or saccades) are not controlled by the experimenter and can be shorter than the latencies of the potentials of interest.The fact that this assumption is not verified gives a distorted estimate of the evoked potential due to overlaps between the evoked potentials.We have therefore used the Linear Model (GLM), a well-known linear regression method, to estimate the potentials evoked by ocular movements in order to take into account overlaps. First, we decided to introduce a term of Tikhonov regularization into this model in order to improve the signal-to-noise ratio of the estimate for a small number of trials. Then, we compared the GLM to the ADJAR algorithm in a context of joint EEG and eye-tracking recording during a task of visual exploration of natural scenes. The ADJAR ("ADJAcent Response") algorithm is an algorithm for iterative estimation of temporal overlaps developed in 1993 by M. Woldorff. The results showed that the GLM model was more flexible and robust than the ADJAR algorithm in estimating Eye-Fixation Related Potentials. Further, two GLM configurations were compared in their estimation of evoked potential at the onset of the stimulus and the eye-fixation related potential at the beginning of the testing. Both configurations took into account the overlaps between evoked potentials, but one additionally distinguished the potential evoked by the first fixation of the exploration from the potential evoked by the following fixations. It became clear that the choice of the GLM configuration was a compromise between the estimation quality of the potentials and the assumptions about the underlying cognitive processes.Finally, we conducted an extensive joint EEG and eye-tracking experiment on the exploration of static and dynamic natural emotional facial expressions. We presented the first results for the static modality. After discussing the estimation method of the evoked potentials according to the impact of the ocular movements on their latency window, we studied the influence of the type of emotion. We found modulations of the differential EPN (Early Posterior Negativity) potential, between 230 and 350 ms after the stimulus onset and the Late Positivity Potential (LPP) , between 400 and 600 ms after the stimulus onset. We also observed variations for the Eye-Fixation Related Potentials. Regarding the LPP component, a marker of conscious recognition of emotion, we have shown that it is important to dissociate information that is immediately encoded at the onset of the emotional stimulus from information encoded at the first fixations. This shows a differentiated pattern of activation according to the emotional stimulus valence. This differentiation is in agreement with the hypothesis of a faster treatment of negative emotional stimuli than of positive emotional stimuli.

[pt] Um dos principais problemas em manufatura é como ajustar um processo de produção que não está obtendo uma performance desejada. O intuito é fazer com que o parâmetro do processo volte a assumir um valor alvo requerido. As técnicas de controle estatístico de processo (CEP) são amplamente utilizadas na indústria para monitorar processos e, conseqüentemente, para melhoria da qualidade. Os gráficos de controle para variáveis mais freqüentemente utilizados para monitorar a média e a variabilidade do processo são os gráficos de Shewhart, os gráficos de CUSUM e os gráficos de EWMA. Porém, as considerações básicas para se utilizar um gráfico de Shewhart são que os dados gerados pelo processo sejam independentes e identicamente distribuídos (IID). Quando a hipótese de independência dos dados não é satisfeita, tais gráficos não funcionam bem, pois fornecerão resultados não confiáveis na forma de excesso de alarme falsos, ou seja, conduz a interpretações equivocadas acerca do processo e gera custos adicionais de controle. Esta tese utiliza uma formulação bayesiana, o Modelo Linear Dinâmico de Harrison & Stevens (MLD-HS) para o monitoramento da média de processos cujas observações podem ser modeladas como um processo ARMA (1,1). O Fator de Bayes acumulado foi utilizado na detecção de desvios na média de um dado processo. Posteriormente, os resultados obtidos pelo modelo proposto, que foi nomeado como MLD-CEP, são comparados aos resultados obtidos por Lu & Reynolds (2001). Os resultados obtidos pelo MLD-CEP sugerem bom desempenho na detecção de alterações na média em processos de baixo a moderadamente alto nível de autocorrelação. / [en] Monitoring a manufacturing process is an important subject in the industries currently. Statistical process control techniques are widely used for process monitoring and quality improvement. Control charts for variables more often used to control both process mean and variance are Shewhart control charts, CUSUM charts and EWMA charts. However, the basic assumptions to use a Shewhart chart are: independent and identically distributed observations (IID); but,autocorrelation may be present in many process, and may have a strong impact nthe properties of control charts. This thesis used a bayesian formulation, Dynamic Linear Model of Harrison & Stevens (MLD-HS), for monitoring the process mean for the situation in which observations from the process can be modeled as an ARMA(1,1). The cumulative Bayes factor has been used for detecting shifts on the process mean. After that, the results obtained by MLD-CEP are compared with the results obtained by Lu & Reynolds (2001). The MLD-CEP results indicate a good performance in detecting shifts in the process mean.