É muito importante que se reconheça os fatores relacionados com à má oclusão que ocorrem em uma determinada população à fim de que medidas preventivas e tratamentos ortodônticos possam ser conduzidos. O objetivo do presente estudo epidemiológico foi obter dados representativos sobre fatores relacionados com as más oclusões na dentição decídua e mista no Equador. Os responsáveis por 400 crianças, de 3 a 9 anos, em atendimento na Faculdade de Odontologia da Universidade Central do Equador foram questionados, incialmente, quanto aos dados pessoais, histórico familiar e saúde. Em sequência as crianças foram examinadas, clinicamente, extra e intra oralmente. O exame funcional, avaliação de hábitos e nível socioeconômico também foram conduzidos por um único avaliador. Os dados obtidos foram tabulados para se obter tabelas de frequência e porcentagem. Foi aplicado o Teste Qui quadrado ou Teste de Fisher (p<0,05). Um número maior de crianças com má oclusão (77%) foi encontrado do que crianças com oclusão adequada (p=0,00001). Não se pode afirmar que houve correlação significativa entre classe socioeconômica e má oclusão (p=0,12). Houve predomínio do hábito de morder objetos estranhos e onicofagia. 33,33% das crianças com mordida aberta apresentavam respiração bucal, no entanto, entre as crianças que apresentaram outros tipos de oclusão, 32,47% tinham respiração bucal. A sucção digital foi encontrada em 14% das crianças. Conclui-se que existe um número significante de má oclusão; há correlação entre interferências oclusais e a presença de mordida cruzada; a atrição fisiológica desenvolve-se com o avanço da idade; não houve associação significativa entre respiração bucal e mordida aberta e o nível sócio econômico não interfere nas características de oclusão. / It is very important to recognize the factors related to bad occlusion that occur in a certain population so that the measures Preventive and orthodontic treatments can be carried out. The objective of the present epidemiological study was to obtain representative data on factors related to malocclusions in deciduous and mixed dentition in Ecuador. Those responsible for 400 children, from 3 to 9 years old, in care in School of Dentistry of the Central University of Ecuador were respondents, in terms of personal data, family history and Health. In sequence the children were examined, clinically, extra and intra orally. Functional examination, evaluation of habits and socioeconomic status They were conducted by a single researcher. The data They were tabulated to obtain frequency and percentage tables. The application was applied Chi square test or Fisher\'s test (p <0.05). A greater number of Children with malocclusion (77%) were found to be children with correct occlusion (p = 0.00001). It cannot be said that there was significant correlation between socioeconomic class and bad occlusion (p = 0.12). A predominance was observed the habit of biting foreign objects and Onychophagia. 33.33% of children with open bite had mouth breathing, however, among children who presented other types of occlusion, 32.47% had mouth breathing. The digital suction 14% of children were found. It is concluded that there is a significant number of malocclusion; there is correlation between occlusal interferences and the presence of a crossbite; Physiological attrition develops as Age advances; there was no significant association between mouth breathing and open bite and socioeconomic status does not interfere with the characteristics of occlusion.

Due to the natural, non-intrusive, easily collectible, widespread applicability, machine-based face recognition has received significant attention from the biometrics community over the past three decades. Compared with traditional appearance-based (2D) face recognition, shape-based (3D) face recognition is more stable to illumination variations, small head pose changes, and varying facial cosmetics. However, 3D face scans captured in unconstrained conditions may lead to various difficulties, such as non-rigid deformations caused by varying expressions, data missing due to self occlusions and external occlusions, as well as low-quality data as a result of some imperfections in the scanning technology. In order to deal with those difficulties and to be useful in real-world applications, in this thesis, we propose two 3D face recognition approaches: one is focusing on handling various expression changes, while the other one can recognize people in the presence of large facial expressions, occlusions and large pose various. In addition, we provide a provable and practical surface meshing algorithm for data-quality improvement. To deal with expression issue, we assume that different local facial region (e.g. nose, eyes) has different intra-expression/inter-expression shape variability, and thus has different importance. Based on this assumption, we design a learning strategy to find out the quantification importance of local facial regions in terms of their discriminating power. For facial description, we propose a novel shape descriptor by encoding the micro-structure of multi-channel facial normal information in multiple scales, namely, Multi-Scale and Multi-Component Local Normal Patterns (MSMC-LNP). It can comprehensively describe the local shape changes of 3D facial surfaces by a set of LNP histograms including both global and local cues. For face matching, Weighted Sparse Representation-based Classifier (W-SRC) is formulated based on the learned quantification importance and the LNP histograms. The proposed approach is evaluated on four databases: the FRGC v2.0, Bosphorus, BU-3DFE and 3D-TEC, including face scans in the presence of diverse expressions and action units, or several prototypical expressions with different intensities, or facial expression variations combine with strong facial similarities (i.e. identical twins). Extensive experimental results show that the proposed 3D face recognition approach with the use of discriminative facial descriptors can be able to deal with expression variations and perform quite accurately over all databases, and thereby has a good generalization ability. To deal with expression and data missing issues in an uniform framework, we propose a mesh-based registration free 3D face recognition approach based on a novel local facial shape descriptor and a multi-task sparse representation-based face matching process. [...]

Dans cette thèse, nous nous intéressons au problème du suivi comportemental des piétons au sein d'un environnement critique partiellement observé. Tandis que plusieurs travaux de la littérature s'intéressent uniquement soit à la position d'un piéton dans l'environnement, soit à l'activité à laquelle il s'adonne, nous optons pour une vue générale et nous estimons simultanément à ces deux données. Les contributions présentées dans ce document sont organisées en deux parties. La première partie traite principalement du problème de la représentation et de l'exploitation du contexte environnemental dans le but d'améliorer les estimations résultant du processus de suivi. L'état de l'art fait mention de quelques études adressant cette problématique. Dans ces études, des modèles graphiques aux capacités d'expressivité limitées, tels que des réseaux Bayésiens dynamiques, sont utilisés pour modéliser des connaissances contextuelles a priori. Dans cette thèse, nous proposons d'utiliser des modèles contextuelles plus riches issus des simulateurs de comportements d'agents autonomes et démontrons l’efficacité de notre approche au travers d'un ensemble d'évaluations expérimentales. La deuxième partie de la thèse adresse le problème général d'influences mutuelles - communément appelées interactions - entre piétons et l'impact de ces interactions sur les comportements respectifs de ces derniers durant le processus de suivi. Sous l'hypothèse que nous disposons d'un simulateur (ou une fonction) modélisant ces interactions, nous développons une approche de suivi comportemental à faible coût computationnel et facilement extensible dans laquelle les interactions entre cibles sont prises en compte. L'originalité de l'approche proposée vient de l'introduction des "représentants'', qui sont des informations agrégées issues de la distribution de chaque cible de telle sorte à maintenir une diversité comportementale, et sur lesquels le système de filtrage s'appuie pour estimer, de manière fine, les comportements des différentes cibles et ceci, même en cas d'occlusions. Nous présentons nos choix de modélisation, les algorithmes résultants, et un ensemble de scénarios difficiles sur lesquels l’approche proposée est évaluée / In this thesis, we are interested in the problem of pedestrian behavioral tracking within a critical environment partially under sensory coverage. While most of the works found in the literature usually focus only on either the location of a pedestrian or the activity a pedestrian is undertaking, we stands in a general view and consider estimating both data simultaneously. The contributions presented in this document are organized in two parts. The first part focuses on the representation and the exploitation of the environmental context for serving the purpose of behavioral estimation. The state of the art shows few studies addressing this issue where graphical models with limited expressiveness capacity such as dynamic Bayesian networks are used for modeling prior environmental knowledge. We propose, instead, to rely on richer contextual models issued from autonomous agent-based behavioral simulators and we demonstrate the effectiveness of our approach through extensive experimental evaluations. The second part of the thesis addresses the general problem of pedestrians’ mutual influences, commonly known as targets’ interactions, on their respective behaviors during the tracking process. Under the assumption of the availability of a generic simulator (or a function) modeling the tracked targets' behaviors, we develop a yet scalable approach in which interactions are considered at low computational cost. The originality of the proposed approach resides on the introduction of density-based aggregated information, called "representatives’’, computed in such a way to guarantee the behavioral diversity for each target, and on which the filtering system relies for computing, in a finer way, behavioral estimations even in case of occlusions. We present the modeling choices, the resulting algorithms as well as a set of challenging scenarios on which the proposed approach is evaluated

Kang, Ning. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Abstract also in Chinese. / Abstracts --- p.i / Abbreviations --- p.v / List of Figures and Tables --- p.vii / Contents --- p.viii / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1. --- Saphenous vein graft patency after coronary artery bypass grafting --- p.1 / Chapter 2. --- Mechanism of vein graft failure and therapeutic strategies --- p.8 / Chapter 2.1 --- Mechanism --- p.15 / Chapter 2.2 --- Therapeutic strategies --- p.18 / Chapter 3. --- Summary --- p.22 / Chapter 4. --- References --- p.23 / Chapter Chapter 2: --- Animal model and laboratory investigations --- p.34 / Chapter 1. --- Surgical procedure --- p.35 / Chapter 2. --- Postoperative management --- p.37 / Chapter 3. --- Adenoviral-mediated gene transfer ex vivo for gene therapy study --- p.38 / Chapter 4. --- Laboratory investigations --- p.39 / Chapter 5. --- Statistical analysis --- p.40 / Chapter 6. --- Summary --- p.41 / Chapter 7. --- References --- p.41 / Chapter Chapter 3: --- "Impact of osteopontin expression in vein grafts on VSMC migration, proliferation, and neointimal formation" --- p.42 / Chapter 1. --- Introduction --- p.42 / Chapter 2. --- Methods and materials --- p.43 / Chapter 3. --- Results --- p.43 / Chapter 4. --- Discussion --- p.49 / Chapter 5. --- Summary --- p.52 / Chapter 6. --- References --- p.53 / Chapter Chapter 4: --- Potential Role of gene therapy in prevention of vein graft failure --- p.56 / Chapter 1. --- Vectors --- p.56 / Chapter 2. --- "Reporter gene, timing and titer" --- p.57 / Chapter 3. --- Candidate genes --- p.58 / Chapter 4. --- Summary --- p.64 / Chapter 5. --- References --- p.66 / Chapter Chapter 5: --- Conclusions --- p.70 / Acknowledgements --- p.72

Cette dissertation traite du problème du suivi d'objets visuels, dont le but est de localiser un objet et de déterminer sa trajectoire au cours du temps. En particulier, nous nous concentrons sur les scénarios difficiles, dans lesquels les objets subissent d'importantes déformations et occlusions, ou quittent le champs de vision. A cette fin, nous proposons deux méthodes robustes qui apprennent un modèle pour l'objet d'intérêt et le mettent à jour, afin de refléter ses changements au cours du temps.Notre première méthode traite du problème du suivi dans le cas où les objets subissent d'importantes transformations géométriques comme une rotation ou un changement d'échelle. Nous présentons un nouvel algorithme de sélection de propositions, qui étend l'approche traditionnelle de ``suivi par détection''. Cette méthode procède en deux étapes: proposition puis sélection. Dans l'étape de proposition, nous construisons un ensemble de candidats qui représente les localisations potentielles de l'objet en estimant de manière robuste les transformations géométriques. La meilleure proposition est ensuite sélectionnée parmi cet ensemble de candidats pour précisément localiser l'objet en utilisant des indices d'apparence et de mouvement.Dans un second temps, nous traitons du problème de la mise à jour de modèles dans le suivi visuel, c'est-à-dire de déterminer quand il est besoin de mettre à jour le modèle de la cible, lequel peut subir une occlusion, ou quitter le champs de vision. Pour résoudre cela, nous utilisons des indices de mouvement pour identifier l'état d'un objet de manière automatique et nous mettons à jour le modèle uniquement lorsque l'objet est entièrement visible. En particulier, nous utilisons des trajectoires à long terme ainsi qu'une technique basée sur la coup de graphes pour estimer les parties de l'objet qui sont visibles.Nous avons évalué nos deux approches de manière étendue sur différents bancs d'essai de suivi, en particulier sur le récent banc d'essai de suivi en ligne et le jeu de donnée du concours de suivi visuel. Nos deux approches se comparent favorablement à l'état de l'art et font montre d'améliorations significatives par rapport à plusieurs autres récents suiveurs. Notre soumission au concours de suivi d'objets visuels de 2015 a par ailleurs remporté l'une de ces compétitions. / In this dissertation we address the problem of visual object tracking, whereinthe goal is to localize an object and determine its trajectory over time. Inparticular, we focus on challenging scenarios where the object undergoessignificant transformations, becomes occluded or leaves the field of view. Tothis end, we propose two robust methods which learn a model for the object ofinterest and update it, to reflect its changes over time.Our first method addresses the tracking problem in the context of objectsundergoing severe geometric transformations, such as rotation, change in scale.We present a novel proposal-selection algorithm, which extends the traditionaldiscriminative tracking-by-detection approach. This method proceeds in twostages -- proposal followed by selection. In the proposal stage, we compute acandidate pool that represents the potential locations of the object byrobustly estimating the geometric transformations. The best proposal is thenselected from this candidate set to localize the object precisely usingmultiple appearance and motion cues.Second, we consider the problem of model update in visual tracking, i.e.,determining when to update the model of the target, which may become occludedor leave the field of view. To address this, we use motion cues to identify thestate of the object in a principled way, and update the model only when theobject is fully visible. In particular, we utilize long-term trajectories incombination with a graph-cut based technique to estimate parts of the objectsthat are visible.We have evaluated both our approaches extensively on several trackingbenchmarks, notably, recent online tracking benchmark and the visual objecttracking challenge datasets. Both our approaches compare favorably to thestate of the art and show significant improvement over several other recenttrackers. Specifically, our submission to the visual object tracking challengeorganized in 2015 was the winner in one of the competitions.