En vision par ordinateur, les points saillants sont des caractéristiques essentielles aux algorithmes. Les performances dépendent de paramètres extérieurs (ex. illumination). Les mesures de similarité sont centrales à la reconnaissance. Pour assurer l'efficacité de traitement, les caractéristiques extraites d'une image doivent être stables, et la mesure de similarité doit les distinguer parfaitement.Dans cette thèse, des caractéristiques conjointes géométrie/couleur sont étudiées : lignes de couleur et régions. Elles fondent la détection d'une troisième, la profondeur, qui sert en retour à évaluer leurs performanceLes lignes sont des extensions des classiques lignes de niveau: l'espace couleur 3-D est projeté sur un espace 1-D adapté pour résumer l'information chromatique là où elle est adéquate,Les régions exploitent classiquement la connexité image mais jointe à une compacité dans l'histogramme bidimensionnel issu du modèle dichromatique. L'homogénéité ainsi définie garantit une robustesse a priori aux variations d'éclairage en séparant la couleur de l'intensité et les couleurs entre elles.Cette homogénéité est exploitée selon 2 méthodes d'extraction d'ensembles compacts autour des modes de l'histogramme: extraction analytique des extrema locaux de couleur, extraction de ces mêmes extrema contrôlée par les régions correspondantes de l'image.Pour la profondeur, trois calculs de disparité stéréoscopique sont proposés et les performances comparées avec la réalité terrain:1. Appariement de lignes couleur avec une distance de Hausdorff revisitée.2. Exploitation de la forme des histogrammes de disparité par régions3.Coopération entre appariement de points et de régions. / In computer vision, salient points are essential features to algorithms. Performances depend on external parameters (e.g. illuminant). Similarity measures are central to recognition.To secure the processing efficiency, extracted features have to be stable enough, and the similarity measure needs to perfectly distinguish between them.In the thesis, joint geometrical and color features are studied: color lines and regions. They found the detection of a third one, range, that helps in turn to assess their goodness.Color lines are extensions of classical level lines: the 3 D color space is mapped onto a 1 D scale especially designed to retain the chromatic information where it is suitable.Regions require the usual image connectivity but in association with compactness in the bi-dimensional histogram stemming from the dichromatic model. The so-designed homogeneity is granting an a priori good robustness against illumination variations in separating the body colors and splitting color from intensity.The latter homogeneity gives raise to 2 methods for extracting compact sets around histogram modes: color first analysis (an analytic extraction of color local extrema) , and joint color/space analysis (same but controlled by the region growing).As for depth, 3 methods to compute the stereo disparity are proposed for their results to be confronted with the ground-truth:1. Color line matching based on a modified Hausdorff distance,2. Studying the shape of the disparity histogram between regions,3. Cooperation between pixel correlation and region matching.The robustness of the designed features is proved on several stereo pairs. Future work deals with improving efficacy and accuracy.

We investigate some problems commonly found when dealing with stereo images. Working within the context of visual effects for films, we explore software solutions to issues arising with stereo images captured on-set. These images originate from a wide variety of hardware which may or may not provide additional data support for post-production needs. Generic software solutions are thus greatly to be preferred. This dissertation documents contributions in the following three areas. Each project was undertaken at Double Negative and investigated with the aim of improving the post-production pipeline for 3D films. Colour matching is the process whereby the colours of one view from a stereo pair are matched with those of the other view. This process is necessary due to the fact that slight differences in hardware and viewing angle can result in some surprisingly large colour discrepancies. Chapter 3 presents a novel approach to colour matching between stereo pairs of images, with a new tool for visual effects artists given in section 6.2.Vertical alignment of stereo images is key to providing a comfortable experience for the viewer, yet we are rarely presented with perfectly aligned footage from the outset. In chapter 4 we discuss the importance of correcting misalignments for both the final audience and the artists working on these images. We provide a tool for correcting misalignments in section 6.3.Disparity maps are used in many areas of post-production, and so in chapter 5 we investigate ways in which disparity map generation can be improved for the benefit of many existing tools at Double Negative. In addition, we povide an extensive exploration of the requirements of 3D films in order to make them presentable in the cinema. Through these projects, we have provided improvements to the stereo workflow and shown that academic research is a necessary component of developing tools for the visual effects pipeline. We have provided new algorithms to improve the 3D experience for moviegoers, as well as artists, and conclude by discussing the future work that will provide further gains in the field.

Depuis 1979, la Chine a entrepris les politiques des Réformes et de l’Ouverture. Cette période marque un tournant de la Chine. La libéralisation du marché, l’industrialisation et l’internationalisation, qui sont réalisées de manière systématique et graduelle, ont permis d’intégrer la Chine dans l’économie mondiale et la mondialisation. En étudiant le processus de la mondialisation et du développement régional en Chine, nous pouvons constater une évolution multipolaire : une transition de l’économie traditionnelle, planifiée et fermée vers une économie moderne et ouverte du marché, une transformation d’une société agricole vers une société industrielle et de services et un changement conceptuel du centrisme chinois et de tradition vers la mondialisation et la modernité. Cette évolution est le résultat des forces irrésistibles de la mondialisation et des expériences de la Chine quant à son refus, sa résistance, son acceptation forcée, et ses essais en matière d’apprentissage vers la mondialisation. Cependant, la croissance n’est pas partagée de manière équilibrée entre les régions de la Chine. En raison des différences dans l’environnement naturel, dans les ressources, dans les structures industrielles, dans le développement social et compte tenu des éléments historiques et politiques, le développement des régions retardées est une question qui relève non seulement de la stabilité économique et politique de la Chine, mais aussi d’une source de durabilité de la croissance chinoise. Les IDE sont un des facteurs contribuant à la croissance économique en Chine, mais ils ne sont pas les seuls facteurs fautifs à l’écart de la disparité en Chine. / Since 1979, China has undertaken the policies of the Reforms and the Opening. This period marks a turning-point of China. The liberalization of the market, the industrialization and the internationalization, which are carried out in a systematic and gradual way, made it possible to integrate China in the world economy and globalization. By studying the process of globalization and regional development in China, we can observe a multiple evolution: a transition from the traditional economy, planned and closed towards an economy modern and opened market, a transformation of an agricultural society towards an industrial society and services and a conceptual change of the Chinese centrism and tradition towards globalization and modernity. This evolution is the result of the irresistible forces of the globalization and the experiments of China as for its refusal, its resistance, its acceptance forced, and its tests as regards training towards globalization. However, the growth of China is not shared in a balanced way between the regions of China. Because of the differences in natural environment, in the resources, the industrial structures, social development and taking into account the historical and political elements, the development of the delayed areas of China is a question which concerns not only the economic stability and policy of China, but also of a source of durability of the Chinese growth. The FDI is one of the factors contributing to the economic growth in China, but they are not the only faulty factors for the disparity in China.

Neural tube defects (NTD) are among the most common birth defects and the leading cause of infant mortality. NTDs occur when the neural tube fails to close during early fetal development. The two most common types of NTD are spina bifida and anencephaly. NTDs result in lifelong complications like musculoskeletal deformities and loss of strength. The etiology of NTDs is complex and involves still unclear environmental and genetic factors. However, one of the well-established risk factors of NTDs is folic acid deficiency. The prevalence of NTDs can be lowered by an adequate intake of folic acid in the periconceptual period. In 1996, the Food and Drug Administration mandated that 140 micrograms of folic acid be added to 100 grams of bleached grain products with the goal of reducing the prevalence of NTDs. In the years following this fortification mandate, studies have shown that blood folate levels have more than doubled on average, that there are demographic and socioeconomic disparities in blood folate gains and that NTD rates have declined. However, no studies after the mandate have examined changes in blood folate distribution and differences in NTD prevalence by a wide range of theoretically and biologically relevant risk factors after the mandate. Using a nationally representative sample of non-institutionalized women of reproductive age, I investigated the relationship between the fortification mandate and blood folate levels. I also examined changes in the range/spread of blood folate distribution after the mandate. Using data on US live births from 45 states and the District of Colombia, the second study examined whether (1) the disparities in blood folate changes translate into differences in NTD prevalence and (2) NTD risk factors moderate the association between the mandate and NTD prevalence,. The final study explored potential unintended impacts of the mandate on birth weight, low birth weight, very low birth weight, high birth weight, and physician-diagnosed developmental delay, asthma and allergies. For this study, I employed samples from the Natality files and the National Survey for Children's Health. The cumulative results of my research suggested that the mandate was associated with increases in blood folate concentration, with greater increases in higher quantiles of the blood folate distribution and that the spread of blood folate distribution after the mandate widened. Additionally, the mandate was associated with a decrease in the prevalence of NTDs in the entire US population although the impact of the mandate was moderated by race/ethnicity, maternal educational attainment, acute illness during pregnancy and infant region of birth. Furthermore, the mandate was associated with other unintended infant and child health outcomes such as average birth weight increases in the population and increased risks of developmental delay among six year olds. This research is the first of its kind to examine changes in the spread of blood folate distribution after the mandate and whether NTD risk factors moderate the association between the mandate and NTD prevalence. It is also the first study to explore potential impacts of the actual mandate (not prenatal folic acid supplementation) on other unintended infant and child health outcomes. The results add significantly to our understanding of the effects of the mandate and have important implications for health care providers, women of reproductive age and policy makers because of the potentially increased risk of developmental delay among children and the increasing disparity in blood folate concentrations after the mandate.

Introduction: The Center for Disease Control (CDC) reports that the maternal mortality ratio (MMR) in 1987 was 7.2 deaths per 100,000 live births compared to 18.0 deaths in 2015. This increase in MMR has occurred disproportionately. The same report demonstrates that black women are more than 3 times as likely to die of pregnancy-related causes than non-Hispanic white women. The present study explores how structural differences in the economy, education system, and public policy affect the health of black, pregnant women in the U.S. Methods: This research examined epidemiological studies of maternal mortality in the U.S. Data from previous studies was used to investigate the relationship between the racial disparity in MMR and societal, economic, and political factors that contribute to said relationship. Data from the Center for Disease Control (CDC), the U.S. Census Bureau, the United Nations (UN), and the Claremont Colleges Library network was examined. Results: Studies show that between 2008-2012, black women were found to have the greatest prevalence of preexisting conditions prior to pregnancy. Furthermore, white women are more likely to have their labor induced than black, Asian, and Hispanic women. The increased prevalence of preexisting conditions among black women can be greatly attributed to factors stemming from institutional racism. These factors include less access to health care, education, and equal economic opportunities. Conclusion: Implicit bias among practicing health professionals must be addressed via multiethnic education. It is necessary to create an equally safe environment for women of all races. Additionally, health care providers should take on the responsibility of educating pregnant women about any possible preexisting chronic conditions to properly care for themselves. Prenatal health education must be made readily available and accessible to all demographics. Reports demonstrate that the creation of standardized, disease-specific procedures that target chronic conditions may reduce the U.S. MMR. For black women to overcome the current rates of comorbidity, U.S. public policy must change in a way that decreases the disparity in the socioeconomic status of all Americans.

Does wage disparity, measured as the difference between highest and lowest paid workers, affect the quality of reported financial information? I collect accounting professional wage data from an international accounting and finance employment placement firm for the period of 1972 to 2017. I investigate to what degree wage disparity in corporate and public accounting has affected accounting information quality by testing predictions derived from equity theory and tournament theory. I find that vertical wage disparity within, as well as horizontal wage disparity between, corporate and public accounting is associated with measures of the relevance and reliability of accounting information. Specifically, pay disparity within corporate accounting is associated with a significant reduction in earnings persistence, in the earnings-returns relationship, in the accruals-cashflow relationship, and with higher levels of absolute abnormal accruals. In tests of pay disparity within the public accounting profession I find evidence of improved information quality associated with higher pay disparity. These findings are consistent with the different structures of employment and career advancement within the corporate and public accounting professions.

The Anderson and Aday access framework (1974) is utilized to investigate the association of individual and community level, predisposing, socio-demographic, and enabling factors, on potential and realized access to coronary heart disease (CHD) preventive care. The cross-sectional study is based on a sample of adults age 18-85 from the Medical Expenditure Panel Survey (MEPS) who were identified with CHD risk or who had a CHD diagnosis.Variables from the MEPS and the Area Resource File (ARF) are used to test logistic regression models for dependent variables measuring primary and secondary CHD preventive care services. The primary preventive care measures include blood cholesterol testing, blood pressure checks, and, diet, exercise and smoking cessation counseling. The secondary preventive measures include beta-blocker reciept after myocardial infarction (MI) and statin drug use for the treatment of high blood cholesterol.Being uninsured is associated with a reduced likelihood of receiving primary CHD preventive care. Overall study results indicated gender and race are more consistent predictors of the receipt of CHD preventive care services than individual enabling or community characteristics. Women had a greater likelihood of receiving primaryCHD preventive care services than men. Hispanics are less likely than Caucasians to receive primary CHD preventive care services, except for blood cholesterol testing for which they are more likely to receive. Blacks are more likely than Caucasians to have blood cholesterol testing, but are no less likely to receive the other primary CHD preventive care measures. Blacks demonstrate a lower likelihood of receiving secondary CHD preventive care than Caucasians, specifically beta-blocker post myocardial infarction indicating that disparities in secondary CHD preventive care persist for segments of the study population. Persons over 75 years of age are less likely to receive primary CHD preventive care services as well as the secondary preventive measure ofstatin use for high blood cholesterol.Community level factors did not improve the logistic regression model for the receipt of CHD preventive care, yet, when predicting potential access for preventive services, persons from a higher percent Hispanic or black community were less likely to have a usual source of care.

The roles of immigration status in preventive health care services among Nigerian immigrants in the United States were investigated in this quantitative, cross-sectional survey study. About 260,724 Nigerian immigrants reside in the Unites States, but many do not complete lifesaving preventive health services such as immunization and screening, a major factor contributing to the rise in the cost of healthcare resultant from their use of emergency room services. This study investigated the extent to which immigration status independently explains the relationship between health disparities and risks in non-completion of preventive health care among Nigerian immigrants in the United States by comparing data from Nigerian immigrant adults residing in the United States to data from the African American adults in the United States. Socio-cognitive theory and the social behavioral model served as the conceptual framework for this study. There were 291 adult Nigerian immigrants in the cross-sectional survey using a purposive sampling technique. The data were analyzed using the Levene's test for homogeneity of variances, the Pearson's Chi- Square test and the Kruskal-Wallis non-parametric test. The Kruskal-Wallis results showed that there was a significant difference in screening for preventive care services among the 4 immigrant status categories (p = .000) based on length of residency in the United States. Understanding the health disparities of this population according to their country of origin and immigration status will assist health providers with awareness of population-specific health needs, and may be beneficial in designing public health programs for this population group.

Many lesbian, gay, bisexual, and transgender (LGBT) individuals report experiencing discrimination in their health care that leads to avoidance of regular appointments with providers. Lack of regular primary care can delay diagnoses of preventable conditions and increase patient risks for chronic disease complications. A systematic review of the literature was conducted to understand LGBT cultural competencies for nursing and other health care providers. The Cochrane Handbook for Systematic Reviews and Melnyk's levels of evidence framed this systematic literature review. Articles for inclusion were limited to those published in English between 2008 and 2018. Keywords used in the literature search included LGBT health disparity, LGBT cultural competency orientation, and nursing LGBT education. The search yielded 70 article results, which were further reduced to 12 articles by critically analyzing the applicability of the literature to the practice-related questions and removing duplicate articles. Five articles met the criteria for Levels III-IV (case-control or cohort), 6 met the criteria for Level II (randomized control trials), and 1 was Level 1 (systematic review). The analysis of evidence demonstrated the importance of providing education to nurses and other health care providers regarding LGBT cultural competency. Recommendations are offered for best practice strategies regarding the inclusion of LGBT cultural competencies in nursing orientation modules. Application of the findings may lead to positive social change if knowledgeable health care providers engage the LGBT population in primary care leading to improved health care outcomes.

Objective: Deficits in temporal resolution may be one element underlying the speech understanding difficulties experienced by older listeners in degraded acoustic environments. In real listening environments, important temporal cues are surrounded by stimuli of varying frequencies. This study was designed to assess temporal resolution as a function of frequency region, frequency-disparity, and age in listeners with normal hearing. Design: Gap duration difference limens (GDDLs) were measured using leading and trailing markers that were fixed at the same frequency (fixed-frequency) or at frequencies one-half octave apart (frequency-disparate) for two groups of listeners with normal hearing: (1) 18-22 years and (2) 55-66 years. Two distinct frequency regions were represented, 500 Hz and 4000 Hz. Results: The results indicated significant effects of age, frequency region, and frequency disparity on GDDLs. Poorer overall performance was observed for the older listeners, the lower frequency region, and the frequency-disparate condition. Conclusions: Gap discrimination is negatively affected by advanced age, lower marker frequencies, and larger marker frequency disparities.