The quadrotor helicopter is a unique flying vehicle which uses the thrust from four motors to provide hover flight capability. The uncoupled nature of the longitudinal and lateral axes and its ability to support large payloads with respect to its size make it an attractive vehicle for autonomous vehicle research. In this thesis, the quadrotor is modeled based on first principles and a proportional-derivative control method is applied for attitude stabilization and position control. A unique means of using an optic flow sensor for velocity and position estimation in an indoor setting is presented with flight results. Reliable hover flight and hallway following capabilities are exhibited in GPS-denied indoor flight using only onboard sensors. Attitude angles can be reliably estimated in the short run by integrating the angular rates from MEMS gyros, but noise on the signal leads to drift which renders the measurement unsuitable to attitude estimation. Typical methods of providing vector attitude corrections such as accelerometers and magnetometers have inherent weaknesses on hovering vehicles. Thus, an additional vector measurement is necessary to correct attitude readings for long-term flights. Two methods of using image processing to determine vanishing points in a hallway are demonstrated. The more promising of the two uses a Hough transform to detect lines in the image and forms a histogram of the intersections to detect likely vanishing point candidates. Once the vanishing point is detected, it acts as a vector measurement to correct attitude estimates on the quadrotor vehicle. Results using onboard vision to estimate heading are demonstrated on a test stand. Together, these capabilities improve the utility of the quadrotor platform for flight without the need of any external sensing capability.

No description available.

This paper investigates garments as containers of stories in Maggie O’Farrell’s The Vanishing Act of Esme Lennox (2007). Michel Foucault’s ideas about penal practice are used to study how items of clothing are used to discipline the female body and sexuality. O’Farrell’s novel is also analyzed from the perspective of trauma theory as presented by Cathy Caruth. In this context, we study how trauma is portrayed through the novel's presence and absence of garments. Further, a didactic perspective is added to our discussion of trauma theory, garments, and Foucault’s theories in the classroom. An issue to be investigated is how a safe space can be created in the classroom so that the teacher may introduce sensitive topics such as rape.   Keywords: garments, Foucault, trauma theory

No description available.

<p>The thesis consists of three research projects concerning mathematical models for analog computers, originally developed by John Tucker and Jeff Zucker. The models are capable of representing systems that essentially “diverge,” exhibiting no valid behaviour---much the way that digital computers are capable of running programs that never halt. While there is no solution to the general Halting Problem, there are certainly theorems that identify large collections of instances that are guaranteed to halt. For example, if we use a simplified language featuring only assignment, branching, algebraic operations, and loops whose bounds must be fixed in advance (i.e. at “compile time”), we know that all instances expressible in this language will halt.</p> <p>In this spirit, one of the major objectives of all three thesis projects is identify a large class of instances of analog computation (analog computer + input) that are guaranteed to “converge.” In our semantic models, this convergence is assured if a certain operator (representing the computer and its input) has a unique fixed point. The first project is based on an original fixed point construction, while the second and third projects are based on Tucker and Zucker's construction. The second project narrows the scope of the model to a special case in order to concretely identify a class of operators with well-behaved fixed points, and considers some applications. The third project goes the opposite way: widening the scope of the model in order to generalize it.</p> / Doctor of Philosophy (PhD)

A redução de custos e a melhora do processo produtivo são essenciais para o aumento da rentabilidade e da produtividade das áreas agrícolas. O investimento em tecnologia se torna, portanto, fundamental em um mundo cada vez mais competitivo. Neste trabalho é apresentado o desenvolvimento de um método de extração da posição de máquinas agrícolas, em relação às linhas de cultivo, a partir do processamento de imagens fornecidas por uma câmera de vídeo colorida. A posição extraída é a informação básica utilizada em um sistema de direcionamento automático, permitindo determinar quais ações devam ser tomadas para manter a máquina em sua trajetória. O correto posicionamento da máquina sobre as linhas de cultivo melhora o processo de pulverização, ocasionando a redução de custos e o aumento da produtividade da área. O método proposto está embasado nos conceitos de ponto de fuga e busca antecipada. Essas técnicas permitiram simplificar o processamento das imagens e conseqüentemente a redução do tempo de processamento. Essas características, aliadas ao correto posicionamento da câmera, devem permitir que o método proposto possa ser utilizado no controle de máquinas agrícolas que operam em grandes velocidades como os pulverizadores. / Cost reduction and productive process improvement are essential to increase yield in agricultural areas. Investments in technology become, therefore, important in a competitive world. This work presents a novel approach for extracting agricultural machine position, with respect to crop rows, processing images captured by a color video camera. The correct machine positioning in crop rows can improve agricultural processes such as spraying, decreasing the costs and increasing the area yield. The proposed method is based on the look-ahead and vanishing points techniques. These techniques allow the reduction of the algorithm complexity and, therefore, the reduction of the processing time. These characteristics added to the camera position may allow the system to control agricultural machines that run at high speeds, such as sprayers.

Introdução: As leucoencefalopatias constituem um vasto grupo de doenças que desafiam a equipe médica. Dentre elas, a doença da Substância Branca Evanescente, é uma das mais comuns, com destaque nos últimos anos pelo significativo avanço na caracterização de suas bases clínicas, moleculares e de imagem. O fenótipo típico tem início dos 2 aos 6 anos, marcado por declínio neurológico crônico e progressivo, com episódios de deterioração desencadeados por trauma ou infecção, que podem levar a coma e até óbito. Essa é uma desordem genética, autossômica recessiva, relacionada a mutações nos genes que codificam o fator iniciador de tradução dos eucariontes 2B (eIF2B), complexo responsável por coordenar a tradução do RNA em proteína. As características típicas na Ressonância Magnética (RM) encefálica, com padrão de acometimento difuso da substância branca e degeneração cística, constituem a forma de diagnóstico mais acessível em associação com os dados clínicos. Objetivo: Caracterizar os casos de doença da Substância Branca Evanescente em relação ao aspecto de imagem, correlação com achados clínicos e moleculares, além de avaliação evolutiva da neuroimagem e comparação com dados da literatura. Método: Delineamento do tipo prospectivo histórico por meio de prontuários e imagens de RM de encéfalo de 13 pacientes com diagnóstico molecular de doença da Substância Branca Evanescente do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - HCFMRPUSP - do período de 2006 a 2016. Resultados: Os pacientes eram na maioria do sexo feminino, todos brancos, com idade média de início dos sintomas aos 10 anos. Todas as mutações foram no gene EIF2B5, sendo prevalente c.338G> A (p.Arg113His). Trauma ou infecção como desencadeante foi descrito em 38,4%. O sintoma mais frequente foi ataxia (100%). Falência ovariana afetou metade das mulheres. Todos os exames de RM mostraram comprometimento da substância branca profunda, poupando relativamente a subcortical, com preferência frontoparietal (84,6%). Todas apresentaram lesões no corpo caloso e envolvimento cerebelar. Atrofia óptica acometeu 46,1%. Espectroscopia de prótons mostrou redução dos valores de Nacetil-aspartato e pico de lactato. O seguimento em imagem evidenciou evolução das lesões na substância branca e da atrofia, com maior acometimento da alta convexidade e dilatação ventricular, porém sem colapso do parênquima. Concomitantemente, o seguimento clínico mostrou piora neurológica progressiva e desfecho desfavorável em 12 dos 13 pacientes. Conclusões: Este é um dos estudos brasileiros com maior casuística de pacientes com diagnóstico molecular de Doença da Substância Branca Evanescente. Embora sendo uma doença multifacetada, os dados epidemiológicos, clínicos e de imagem encontrados foram semelhantes aos classicamente descritos na literatura para outras populações. Ressalta-se, ainda, extrema importância da RM de encéfalo para diagnóstico, evolução e triagem genética dessa desordem. / Introduction: Leukoencephalopathies constitute a vast group of differential diagnoses that challenge the medical team. Among them, Vanishing White Matter (VWM) Disease is one of the most common, and has been highlighted nowadays for significant progress in the characterization of its clinical, molecular and imaging basis. The typical phenotype begins at 2 to 6 years old, marked by chronic and progressive neurological decline, with episodes of deterioration triggered by trauma or infection that can lead to coma and even death. This is a genetic, autosomal recessive disorder related to mutations in the genes that encode the eukaryotic translation initiator factor 2B (eIF2B), a complex responsible for coordinating the translation of RNA into protein. The typical features in brain Magnetic Resonance Imaging (MRI), with a pattern of diffuse white matter involvement and cystic degeneration, are the most accessible form of diagnosis in association with clinical data. Purpose: to characterize VWM disease cases in relation to brain MRI appearance, clinical and molecular correlation and evolution over the time, comparing with data already described. Methods: A prospective historical design was performed using a review of medical records and brain MRI images of 13 patients from Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - HCFMRPUSP - with imaging and molecular diagnostic of VWM disease during the period from 2006 to 2016. Results: The patients were mostly female, all white, with a mean age of symptoms onset at 10 years old. All mutations were in the EIF2B5 gene, the most prevalent of them was c.338G> A (p.Arg113His). Trauma or infection as a trigger was described in 38.4%. The most frequent symptom was ataxia (100%). Ovarian failure affected half of women. All MRI showed deep white matter impairment, in a less prominent degree in the subcortical region, with frontoparietal preference (84.6%). All had lesions in the corpus callosum and cerebellar white matter involvement. Optic atrophy affected 46.1%. Proton spectroscopy showed a reduction in NAA values and a lactate peak. Image follow-up revealed white matter lesions and atrophy progression, with ventricular dilatation, however without parenchymal collapse. Concomitantly, there was progressive neurological worsening and unfavorable outcome in 12 of the 13 patients. Conclusion: This is one of the Brazilian studies with the largest number of patients with molecular diagnosis of VWM Disease. Although it is a multifaceted disease, the epidemiological, clinical and imaging data found were similar to those classically described in the literature for other populations. The importance of brain MRI for the diagnosis, evolution and genetic screening of this disorder is also highlighted.

Neste trabalho estudamos superfícies com a propriedade que suas componentes irredutíveis são superfícies tóricas. Em particular, apresentamos uma fórmula para calcular a obstrução de Euler local destas superfícies. Como uma aplicação desta fórmula, calculamos a obstrução de Euler local para algumas famílias de superfícies determinantais. Além disso, definimos a característica de Euler evanescente de uma superfície tórica normal X&sigma;, damos uma fórmula para calcular tal invariante e relacionamos este número com a segunda multiplicidade polar de X&sigma;. Apresentamos também, uma fórmula para a obstrução de Euler de uma função f : X&sigma; &rarr; C e para o número de Brasselet de tal função. Como uma aplicação deste resultado, calculamos a obstrução de Euler de um tipo de polinômio definido em uma família de superfícies determinantais. / In this work we study surfaces with the property that their irreducible components are toric surfaces. In particular, we present a formula to compute the local Euler obstruction of such surfaces. As an application of this formula we compute the local Euler obstruction for some families of determinantal surfaces. Furthermore, we define the vanishing Euler characteristic of a normal toric surface X&sigma;, we give a formula to compute it, and we relate this number with the second polar multiplicity of X&sigma;. We also present a formula for the Euler obstruction of a function f : X&sigma; &rarr; C and for the Brasselet number of it. As an application of this result we compute the Euler obstruction of a type of polynomial on a family of determinantal surfaces.

Introdução: As leucoencefalopatias constituem um vasto grupo de doenças que desafiam a equipe médica. Dentre elas, a doença da Substância Branca Evanescente, é uma das mais comuns, com destaque nos últimos anos pelo significativo avanço na caracterização de suas bases clínicas, moleculares e de imagem. O fenótipo típico tem início dos 2 aos 6 anos, marcado por declínio neurológico crônico e progressivo, com episódios de deterioração desencadeados por trauma ou infecção, que podem levar a coma e até óbito. Essa é uma desordem genética, autossômica recessiva, relacionada a mutações nos genes que codificam o fator iniciador de tradução dos eucariontes 2B (eIF2B), complexo responsável por coordenar a tradução do RNA em proteína. As características típicas na Ressonância Magnética (RM) encefálica, com padrão de acometimento difuso da substância branca e degeneração cística, constituem a forma de diagnóstico mais acessível em associação com os dados clínicos. Objetivo: Caracterizar os casos de doença da Substância Branca Evanescente em relação ao aspecto de imagem, correlação com achados clínicos e moleculares, além de avaliação evolutiva da neuroimagem e comparação com dados da literatura. Método: Delineamento do tipo prospectivo histórico por meio de prontuários e imagens de RM de encéfalo de 13 pacientes com diagnóstico molecular de doença da Substância Branca Evanescente do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - HCFMRPUSP - do período de 2006 a 2016. Resultados: Os pacientes eram na maioria do sexo feminino, todos brancos, com idade média de início dos sintomas aos 10 anos. Todas as mutações foram no gene EIF2B5, sendo prevalente c.338G> A (p.Arg113His). Trauma ou infecção como desencadeante foi descrito em 38,4%. O sintoma mais frequente foi ataxia (100%). Falência ovariana afetou metade das mulheres. Todos os exames de RM mostraram comprometimento da substância branca profunda, poupando relativamente a subcortical, com preferência frontoparietal (84,6%). Todas apresentaram lesões no corpo caloso e envolvimento cerebelar. Atrofia óptica acometeu 46,1%. Espectroscopia de prótons mostrou redução dos valores de Nacetil-aspartato e pico de lactato. O seguimento em imagem evidenciou evolução das lesões na substância branca e da atrofia, com maior acometimento da alta convexidade e dilatação ventricular, porém sem colapso do parênquima. Concomitantemente, o seguimento clínico mostrou piora neurológica progressiva e desfecho desfavorável em 12 dos 13 pacientes. Conclusões: Este é um dos estudos brasileiros com maior casuística de pacientes com diagnóstico molecular de Doença da Substância Branca Evanescente. Embora sendo uma doença multifacetada, os dados epidemiológicos, clínicos e de imagem encontrados foram semelhantes aos classicamente descritos na literatura para outras populações. Ressalta-se, ainda, extrema importância da RM de encéfalo para diagnóstico, evolução e triagem genética dessa desordem. / Introduction: Leukoencephalopathies constitute a vast group of differential diagnoses that challenge the medical team. Among them, Vanishing White Matter (VWM) Disease is one of the most common, and has been highlighted nowadays for significant progress in the characterization of its clinical, molecular and imaging basis. The typical phenotype begins at 2 to 6 years old, marked by chronic and progressive neurological decline, with episodes of deterioration triggered by trauma or infection that can lead to coma and even death. This is a genetic, autosomal recessive disorder related to mutations in the genes that encode the eukaryotic translation initiator factor 2B (eIF2B), a complex responsible for coordinating the translation of RNA into protein. The typical features in brain Magnetic Resonance Imaging (MRI), with a pattern of diffuse white matter involvement and cystic degeneration, are the most accessible form of diagnosis in association with clinical data. Purpose: to characterize VWM disease cases in relation to brain MRI appearance, clinical and molecular correlation and evolution over the time, comparing with data already described. Methods: A prospective historical design was performed using a review of medical records and brain MRI images of 13 patients from Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - HCFMRPUSP - with imaging and molecular diagnostic of VWM disease during the period from 2006 to 2016. Results: The patients were mostly female, all white, with a mean age of symptoms onset at 10 years old. All mutations were in the EIF2B5 gene, the most prevalent of them was c.338G> A (p.Arg113His). Trauma or infection as a trigger was described in 38.4%. The most frequent symptom was ataxia (100%). Ovarian failure affected half of women. All MRI showed deep white matter impairment, in a less prominent degree in the subcortical region, with frontoparietal preference (84.6%). All had lesions in the corpus callosum and cerebellar white matter involvement. Optic atrophy affected 46.1%. Proton spectroscopy showed a reduction in NAA values and a lactate peak. Image follow-up revealed white matter lesions and atrophy progression, with ventricular dilatation, however without parenchymal collapse. Concomitantly, there was progressive neurological worsening and unfavorable outcome in 12 of the 13 patients. Conclusion: This is one of the Brazilian studies with the largest number of patients with molecular diagnosis of VWM Disease. Although it is a multifaceted disease, the epidemiological, clinical and imaging data found were similar to those classically described in the literature for other populations. The importance of brain MRI for the diagnosis, evolution and genetic screening of this disorder is also highlighted.

Visual surveillance in the maritime domain has been explored for more than a decade. Although it has produced a number of working systems and resulted in a mature technology, surveillance has been restricted to the port facilities or areas close to the coastline assuming a fixed-camera scenario. This dissertation presents several contributions in the domain of maritime surveillance. First, a novel algorithm for open-sea visual maritime surveillance is introduced. We explore a challenging situation with a camera mounted on a buoy or other floating platform. The developed algorithm detects, localizes, and tracks ships in the field of view of the camera. Specifically, our method is uniquely designed to handle a rapidly moving camera. Its performance is robust in the presence of a random relatively-large camera motion. In the context of ship detection, a new horizon detection scheme for a complex maritime domain is also developed. Second, the performance of the ship detection algorithm is evaluated on a dataset of 55,000 images. Accuracy of detection of up to 88% of ships is achieved. Lastly, we consider the topic of detection of the vanishing line of the ocean surface plane as a way to estimate the horizon in difficult situations. This allows extension of the ship-detection algorithm to beyond open-sea scenarios.