742 resultados para Deformable templates


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This thesis proposes a generic visual perception architecture for robotic clothes perception and manipulation. This proposed architecture is fully integrated with a stereo vision system and a dual-arm robot and is able to perform a number of autonomous laundering tasks. Clothes perception and manipulation is a novel research topic in robotics and has experienced rapid development in recent years. Compared to the task of perceiving and manipulating rigid objects, clothes perception and manipulation poses a greater challenge. This can be attributed to two reasons: firstly, deformable clothing requires precise (high-acuity) visual perception and dexterous manipulation; secondly, as clothing approximates a non-rigid 2-manifold in 3-space, that can adopt a quasi-infinite configuration space, the potential variability in the appearance of clothing items makes them difficult to understand, identify uniquely, and interact with by machine. From an applications perspective, and as part of EU CloPeMa project, the integrated visual perception architecture refines a pre-existing clothing manipulation pipeline by completing pre-wash clothes (category) sorting (using single-shot or interactive perception for garment categorisation and manipulation) and post-wash dual-arm flattening. To the best of the author’s knowledge, as investigated in this thesis, the autonomous clothing perception and manipulation solutions presented here were first proposed and reported by the author. All of the reported robot demonstrations in this work follow a perception-manipulation method- ology where visual and tactile feedback (in the form of surface wrinkledness captured by the high accuracy depth sensor i.e. CloPeMa stereo head or the predictive confidence modelled by Gaussian Processing) serve as the halting criteria in the flattening and sorting tasks, respectively. From scientific perspective, the proposed visual perception architecture addresses the above challenges by parsing and grouping 3D clothing configurations hierarchically from low-level curvatures, through mid-level surface shape representations (providing topological descriptions and 3D texture representations), to high-level semantic structures and statistical descriptions. A range of visual features such as Shape Index, Surface Topologies Analysis and Local Binary Patterns have been adapted within this work to parse clothing surfaces and textures and several novel features have been devised, including B-Spline Patches with Locality-Constrained Linear coding, and Topology Spatial Distance to describe and quantify generic landmarks (wrinkles and folds). The essence of this proposed architecture comprises 3D generic surface parsing and interpretation, which is critical to underpinning a number of laundering tasks and has the potential to be extended to other rigid and non-rigid object perception and manipulation tasks. The experimental results presented in this thesis demonstrate that: firstly, the proposed grasp- ing approach achieves on-average 84.7% accuracy; secondly, the proposed flattening approach is able to flatten towels, t-shirts and pants (shorts) within 9 iterations on-average; thirdly, the proposed clothes recognition pipeline can recognise clothes categories from highly wrinkled configurations and advances the state-of-the-art by 36% in terms of classification accuracy, achieving an 83.2% true-positive classification rate when discriminating between five categories of clothes; finally the Gaussian Process based interactive perception approach exhibits a substantial improvement over single-shot perception. Accordingly, this thesis has advanced the state-of-the-art of robot clothes perception and manipulation.

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Despite significant progress in the field of tissue engineering within the last decade, a number of unsolved problems still remain. One of the most relevant issues is the lack of proper vascularization that limits the size of engineered tissues to smaller than clinically relevant dimensions. In particular, the growth of engineered tissue in vitro within bioreactors is plagued with this challenge. Specifically, the tubular perfusion system bioreactor has been used for large scale bone constructs; however these engineered constructs lack inherent vasculature and quickly develop a hypoxic core, where no nutrient exchange can occur, thus leading to cell death. Through the use of 3D printed vascular templates in conjunction with a tubular perfusion system bioreactor, we attempt to create an endothelial cell monolayer on 3D scaffolds that could potentially serve as the foundation of inherent vasculature within these engineered bone grafts.

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Les petites molécules de type p à bandes interdites étroites sont de plus en plus perçues comme des remplaçantes possibles aux polymères semi-conducteurs actuellement utilisés conjointement avec des dérivés de fullerènes de type n, dans les cellules photovoltaïques organiques (OPV). Par contre, ces petites molécules tendent à cristalliser facilement lors de leur application en couches minces et forment difficilement des films homogènes appropriés. Des dispositifs OPV de type hétérojonction de masse ont été réalisés en ajoutant différentes espèces de polymères semi-conducteurs ou isolants, agissant comme matrices permettant de rectifier les inhomogénéités des films actifs et d’augmenter les performances des cellules photovoltaïques. Des polymères aux masses molaires spécifiques ont été synthétisés par réaction de Wittig en contrôlant précisément les ratios molaires des monomères et de la base utilisée. L’effet de la variation des masses molaires en fonction des morphologies de films minces obtenus et des performances des diodes organiques électroluminescentes reliées, a également été étudié. La microscopie électronique en transmission (MET) ou à balayage (MEB) a été employée en complément de la microscopie à force atomique (AFM) pour suivre l’évolution de la morphologie des films organiques minces. Une nouvelle méthode rapide de préparation des films pour l’imagerie MET sur substrats de silicium est également présentée et comparée à d’autres méthodes d’extraction. Motivé par le prix élevé et la rareté des métaux utilisés dans les substrats d’oxyde d’indium dopé à l’étain (ITO), le développement d’une nouvelle méthode de recyclage eco-responsable des substrats utilisés dans ces études est également présenté.

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As exigências da sociedade atual obrigam a mudanças tecnológicas cada vez mais rápidas e constantes para satisfazer as necessidades empresariais, especialmente no que concerne à transmissão de informações de forma cada vez mais rápidas, mas sempre mantendo um elevado padrão de qualidade de conteúdos, bem como níveis de segurança elevados para impedir que os mesmos sejam corrompidos. Desde o aparecimento da Internet que a informação circula de forma cada vez mais veloz, em maiores quantidades e alcança cada vez mais pessoas. No entanto, nem todas as pessoas têm acesso a conteúdos de qualidade, sendo nesse ponto que o desenvolvimento do presente trabalho terá importância na respectiva área. O portveb.com é um website que pretende colmatar uma carência de conteúdos de qualidade para especialistas web designers, programadores e optimizadores de motores de busca. A importância do trabalho desenvolvido deve-se à escassez de websites da referida temática, sendo uma oportunidade para explorar a utilização de soluções técnicas como o Bootstrap, HTML, CSS, Javacript, PHP, MYSQL e desenvolver um website cuja funcionalidade não esteja só restrita a computadores pessoais, mas também a plataformas móveis. O desenvolvimento do website portveb.com demonstrou que a utilização das soluções técnicas já referidas foram a melhor opção do que concerne à obtenção de resultados, por assentar em plataformas onde não foi necessário elaborar um design de raíz, sendo que a interacção com bases de dados como PHP e MySQL tornaram o website mais dinâmico. A realização deste trabalho possibilitou ainda a descoberta de potencialidades do website para soluções técnicas futuras que se destinam a aumentar a partilha de conhecimento entre os utilizadores de forma mais prática e eficiente.

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Meso-/microporous zeolites combine the charactersitics of well-defined micropores of zeolite with efficient mass transfer consequences of mesopores to increase the efficiency of the catalysts in reactions involving bulky molecules. Different methods such as demetallation and templating have been explored for the synthesis of meso-/microporous zeolites. However, they all have limitations in production of meso-/microporous zeolites with tunable textural and catalytic properties using few synthesis steps. To address this challenge, a simple one-step dual template synthesis approach has been developed in this work to engineer lamellar meso-/microporous zeolites structures with tunable textural and catalytic properties. First, one-step dual template synthesis of meso-/microporous mordenite framework inverted (MFI) zeolite structures was investigated. Tetrapropyl ammonium hydroxide (TPAOH) and diquaternary ammonium surfactant ([C22H45-N+(CH3)2-C6H12-N+(CH3)2-C6H13]Br2, C22-6-6) were used as templates to produce micropores and mesopores, respectively. The variation in concentration ratios of dual templates and hydrothermal synthesis conditions resulted in production of multi-lamellar MFI and the hybrid lamellar-bulk MFI (HLBM) zeolite structures. The relationship between the morphology, porosity, acidity, and catalytic properties of these catalysts was systematically studied. Then, the validity of the proposed synthesis approach for production of other types of zeolites composites was examined by creating a meso-/microporous bulk polymorph A (BEA)-lamellar MFI (BBLM) composite. The resulted composite samples showed higher catalytic stability compared to their single component zeolites. The studies demonstrated the high potential of the one-step dual template synthesis procedure for engineering the textural and catalytic properties of the synthesized zeolites.

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Different types of heterogeneous catalysts of the silicoaluminophosphate type, (SAPO-5, SAPO-11, SAPO-31, SAPO-34 and SAPO-41), molecular sieves with a: AFI, AEL, ATO, CHA and AFO structure, respectively, were synthesized through the hydrothermal method. Using sources such as hydrated alumina (pseudobohemita), phosphoric acid, silica gel, water, as well as, different types of organic structural templates, such as: cetyltrimethylammonium bromide (CTMABr), di-isopropylamine (DIPA), di-n- propylamine (DNPA) and tetraethylammonium hydroxide (TEOS), for the respective samples. During the preparation of the silicoaluminophosphates, the crystallization process of the samples occurred at a temperature of approximately 200 ° C, ranging through periods of 18-72 h, when it was possible to obtain pure phases for the SAPOs. The materials were furthermore washed with deionized water, dried and calcined to remove the molecules of the templates. Subsequently the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), absorption spectroscopy in the infrared region (FT-IR), specific surface area and thermal analysis via TG/DTG. The acidic properties were determined using adsorption of n-butylamine followed by programmed termodessorption. These methods revealed that the SAPO samples showed a typically weak to moderate acidity. However, a small amount of strong acid sites was also detected. The deactivation of the catalysts was conducted by artificially coking the samples, followed by n-hexane cracking reactions in a fixed bed with a continuous flow micro-reactor coupled on line to a gas chromatograph. The main products obtained were: ethane, propane, isobutene, n-butane, n-pentane and isopentane. The Vyazovkin (model-free) kinetics method was used to determine the catalysts regeneration and removal of the coke

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O uso de dispositivos móveis está a ganhar cada vez mais espaço dentro das organizações. O aumento do consumo de material informático por parte dos consumidores está a levar a que os mesmos comecem a tentar utilizar os seus dispositivos móveis1 Notebooks, Tablets e Smartphones no interior das organizações. Este tipo de comportamento, levou ao aparecimento de uma nova tendência – o Bring Your Own Device (BYOD), a utilização de dispositivos móveis para fins laborais, levanta várias e sérias questões de segurança aos departamentos de TI das organizações, fazendo com que as organizações necessitem de definir novas políticas de segurança para que a sua informação e os seus dados se mantenham seguros. O trabalho adiante desenvolvido pretende mostrar de que forma as organizações veem esta mudança de paradigma, em que os próprios colaboradores utilizam os seus dispositivos móveis como ferramenta de trabalho na organização. Por outro lado analisar os modelos de segurança que se podem associar ao BYOD e aos dispositivos móveis para permitir uma maior segurança dos dados e informação que circula entre a organização e o dispositivo móvel.

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El presente trabajo titulado “Guía Didáctica de Rúbricas de Evaluación para el Bloque Uno de Números y Funciones, dirigida a docentes de matemática de Segundo Año de Bachillerato” ha sido diseñado con la intención de fortalecer el proceso de evaluación a través de la utilización de un nuevo instrumento, la rúbrica; con el objetivo de facilitarla tarea evaluadora del docente. En el primer capítulo, se da a conocer de manera general los cambios que ha sufrido la educación en los últimos años, la necesidad de conocer y relacionar las corrientes pedagógicas innovadoras como el constructivismo y la teoría del aprendizaje significativo con la evaluación del proceso educativo, la didáctica en el ámbito de la matemática, y la implementación de guías didácticas y rúbricas como instrumentos de apoyo para el docente. En el segundo capítulo se busca dar sustento a la propuesta mediante la aplicación de una encuesta, en la cual se evidenciala falta de instrumentos de evaluación que rompan el estigma de la utilización únicamente de pruebas en este proceso, además la factibilidad del uso de una guía didáctica de rúbricas para la matemática. Finalmente, en el tercer capítulo se presentan20 modelos de rúbricas holísticas y analíticas desarrolladas por cada actividad, referidas al Bloque Uno de “Números y Funciones” en base a las Destrezas con Criterio de Desempeño de acuerdo a lo que se establece en el Currículo del sistema educativo ecuatoriano.

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One of the most exciting discoveries in astrophysics of the last last decade is of the sheer diversity of planetary systems. These include "hot Jupiters", giant planets so close to their host stars that they orbit once every few days; "Super-Earths", planets with sizes intermediate to those of Earth and Neptune, of which no analogs exist in our own solar system; multi-planet systems with planets smaller than Mars to larger than Jupiter; planets orbiting binary stars; free-floating planets flying through the emptiness of space without any star; even planets orbiting pulsars. Despite these remarkable discoveries, the field is still young, and there are many areas about which precious little is known. In particular, we don't know the planets orbiting Sun-like stars nearest to our own solar system, and we know very little about the compositions of extrasolar planets. This thesis provides developments in those directions, through two instrumentation projects.

The first chapter of this thesis concerns detecting planets in the Solar neighborhood using precision stellar radial velocities, also known as the Doppler technique. We present an analysis determining the most efficient way to detect planets considering factors such as spectral type, wavelengths of observation, spectrograph resolution, observing time, and instrumental sensitivity. We show that G and K dwarfs observed at 400-600 nm are the best targets for surveys complete down to a given planet mass and out to a specified orbital period. Overall we find that M dwarfs observed at 700-800 nm are the best targets for habitable-zone planets, particularly when including the effects of systematic noise floors caused by instrumental imperfections. Somewhat surprisingly, we demonstrate that a modestly sized observatory, with a dedicated observing program, is up to the task of discovering such planets.

We present just such an observatory in the second chapter, called the "MINiature Exoplanet Radial Velocity Array," or MINERVA. We describe the design, which uses a novel multi-aperture approach to increase stability and performance through lower system etendue, as well as keeping costs and time to deployment down. We present calculations of the expected planet yield, and data showing the system performance from our testing and development of the system at Caltech's campus. We also present the motivation, design, and performance of a fiber coupling system for the array, critical for efficiently and reliably bringing light from the telescopes to the spectrograph. We finish by presenting the current status of MINERVA, operational at Mt. Hopkins observatory in Arizona.

The second part of this thesis concerns a very different method of planet detection, direct imaging, which involves discovery and characterization of planets by collecting and analyzing their light. Directly analyzing planetary light is the most promising way to study their atmospheres, formation histories, and compositions. Direct imaging is extremely challenging, as it requires a high performance adaptive optics system to unblur the point-spread function of the parent star through the atmosphere, a coronagraph to suppress stellar diffraction, and image post-processing to remove non-common path "speckle" aberrations that can overwhelm any planetary companions.

To this end, we present the "Stellar Double Coronagraph," or SDC, a flexible coronagraphic platform for use with the 200" Hale telescope. It has two focal and pupil planes, allowing for a number of different observing modes, including multiple vortex phase masks in series for improved contrast and inner working angle behind the obscured aperture of the telescope. We present the motivation, design, performance, and data reduction pipeline of the instrument. In the following chapter, we present some early science results, including the first image of a companion to the star delta Andromeda, which had been previously hypothesized but never seen.

A further chapter presents a wavefront control code developed for the instrument, using the technique of "speckle nulling," which can remove optical aberrations from the system using the deformable mirror of the adaptive optics system. This code allows for improved contrast and inner working angles, and was written in a modular style so as to be portable to other high contrast imaging platforms. We present its performance on optical, near-infrared, and thermal infrared instruments on the Palomar and Keck telescopes, showing how it can improve contrasts by a factor of a few in less than ten iterations.

One of the large challenges in direct imaging is sensing and correcting the electric field in the focal plane to remove scattered light that can be much brighter than any planets. In the last chapter, we present a new method of focal-plane wavefront sensing, combining a coronagraph with a simple phase-shifting interferometer. We present its design and implementation on the Stellar Double Coronagraph, demonstrating its ability to create regions of high contrast by measuring and correcting for optical aberrations in the focal plane. Finally, we derive how it is possible to use the same hardware to distinguish companions from speckle errors using the principles of optical coherence. We present results observing the brown dwarf HD 49197b, demonstrating the ability to detect it despite it being buried in the speckle noise floor. We believe this is the first detection of a substellar companion using the coherence properties of light.

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This paper describes a novel algorithm for tracking the motion of the urethra from trans-perineal ultrasound. Our work is based on the structure-from-motion paradigm and therefore handles well structures with ill-defined and partially missing boundaries. The proposed approach is particularly well-suited for video sequences of low resolution and variable levels of blurriness introduced by anatomical motion of variable speed. Our tracking method identifies feature points on a frame by frame basis using the SURF detector/descriptor. Inter-frame correspondence is achieved using nearest-neighbor matching in the feature space. The motion is estimated using a non-linear bi-quadratic model, which adequately describes the deformable motion of the urethra. Experimental results are promising and show that our algorithm performs well when compared to manual tracking.

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This paper presents LABNET, an internet-based remote laboratory for control engineering education developed at UEM-University. At present, the remote laboratory integrates three basic physical systems (level control, temperature control and ship stabilizing system). In this paper, the LABNET architecture is presented and discussed in detail. Issues concerned with concurrent user access, local or remote feedback, automatic report generating and reusing of experiment’s templates have been addressed. Furthermore, the experiences gained developing, testing and using the system will be also presented and their consequences for future design.

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This paper describes a novel algorithm for tracking the motion of the urethra from trans-perineal ultrasound. Our work is based on the structure-from-motion paradigm and therefore handles well structures with ill-defined and partially missing boundaries. The proposed approach is particularly well-suited for video sequences of low resolution and variable levels of blurriness introduced by anatomical motion of variable speed. Our tracking method identifies feature points on a frame by frame basis using the SURF detector/descriptor. Inter-frame correspondence is achieved using nearest-neighbor matching in the feature space. The motion is estimated using a non-linear bi-quadratic model, which adequately describes the deformable motion of the urethra. Experimental results are promising and show that our algorithm performs well when compared to manual tracking.

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Entrepreneurship education has emerged as one popular research domain in academic fields given its aim at enhancing and developing certain entrepreneurial qualities of undergraduates that change their state of behavior, even their entrepreneurial inclination and finally may result in the formation of new businesses as well as new job opportunities. This study attempts to investigate the Colombian student´s entrepreneurial qualities and the influence of entrepreneurial education during their studies.

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Las relaciones Internacionales hoy, se abordan bajo la óptica de la interdependencia Compleja caracterizada por variados canales de acción, una agenda múltiple no jerarquizada y la relevancia del conocimiento y la información, lo que desarrollará agilidad en los procesos, la consolidación del mundo 7 x 241, y la desaparición de las fronteras geográficas. Surge así una nueva visión de la política mundial que privilegia la interacción entre los distintos segmentos de las sociedades nacionales en función de múltiples intereses específicos, dentro de un mundo totalmente transnacionalizado, en el cual debe predominar el concepto de bienestar y específicamente, trabajar enfocados en políticas en materia de productividad y de competitividad por medio del comercio electrónico, para elevar los índices de comercio exterior. En este sentido, la multipolaridad2 se presenta como una característica que representa al sistema mundial de hoy, cuando los centros de poder luchan por desarrollar una infraestructura que apoye la base económica, política y social para impulsar la modernización. Hoy es un hecho, aceptado como natural, el que aunque el Estado siga ejerciendo un papel importante en el orden político internacional, progresivamente el monopolio y la centralización del poder sea disgregado en beneficio de los actores transnacionales, dando lugar a lo que se denomina el Estado de Competencia.

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En el presente trabajo se realiza una investigación acerca de la tecnología de liofilización, que comprende un análisis cuantitativo y cualitativo. Esto con la finalidad de conocer la posibilidad de exportar frutas liofilizadas a países pertenecientes de la Unión Europea y la EFTA. La investigación inicia con la recolección de información como la historia de la tecnología de liofilización, su proceso, ventajas y desventajas de aplicación, equipos y funciones necesarias para su realización y se ejemplifican dos empresas colombianas que en la actualidad utilizan esta tecnología. Adicionalmente, se evidencia la diferencia que existe entre este proceso y la deshidratación con calor. Posteriormente, se realiza una matriz de selección de países en la que se tienen en cuenta variables políticas, económicas, culturales y legales de los 32 países pertenecientes a la Unión Europea y la EFTA. Con base en esto se eligieron los dos países cuyo resultado presentaba mayor favorabilidad para la actividad a realizar, estos fueron Suiza y Suecia, para los cuales se hizo un estudio de mercado, teniendo en cuenta seis etapas: contactos, potencial de ventas del mercado, análisis competitivo, condiciones de entrada al país, condiciones financieras y de entrada al mercado y selección del país objetivo. Finalmente se presentan las conclusiones y recomendaciones que la información recolectada permitió obtener.