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1	Composants céramiques 3D innovants pour des applications spatiales de télécommunications millimétriques en bandes Q et V / Advanced technologies for millimeterwave integrated filters in Q and V bands Drissi, Mohamed Khalil 15 December 2016 (has links) Ce mémoire est consacré au développement de technologies de filtrage novatrices qui apportent un gain en performance permettant de répondre aux besoins de filtrage pour télécommunications spatiales à moyen et long termes. Il s’inscrit dans le projet ANR ATOMIQ coordonné par Thales Alenia Space ayant comme partenaires le laboratoire SPCTS et la société 3D CERAM. Le premier chapitre est constitué d’une étude bibliographique sur les filtres en bande Q et V ainsi que les technologies de fabrication 3D. Le deuxième chapitre est consacré à l’élaboration d’une nouvelle formulation d’alumine très pure à faible pertes et stable en température. Le troisième chapitre présente une conception de filtres hyperfréquences en bande Q et V à base de cavités résonantes diélectriques. Le quatrième chapitre concerne la fabrication des filtres par usinage en cru ainsi que la présentation des différents démonstrateurs fabriqués par stéréolithographie et moulage basse pression. Il présente aussi des solutions de correction post-fabrication par tir laser. Ce travail est original par l’utilisation de la stéréolithographie céramique 3D ainsi que du moulage basse pression pour fabriquer des filtres hyperfréquences de petites tailles en bande Q et V. / This thesis focus on the development of innovative filtering technologies that enhance the performance to meet the filtering requirements for spacial communications. It is part of the ANR project ATOMIQ coordinated by Thales Alenia Space with partners (SPCTS 3D CERAM). The first chapter consists of a literature review on the Q and V band filters as well as 3D manufacturing technologies. The second chapter is devoted to the development of a new formulation of highly pure, low losses and temperature stable alumina. The third chapter presents a microwave filter design in Q and V band based on a dielectric resonant cavity. The fourth chapter is about the manufacturing of filters and presentation of various demonstrators manufactured by stereolithography and low pressure molding. It also provides a post-production correction solutions based on laser shoots. This work is original because, to the best of our knowledge, 3D ceramic stereolithography and the low pressure molding have not been used to produce small sizes Q and V band microwave filters. Stéréolithographie céramique 3D Moulage basse pression Usinage en cru Analyse électromagnétique 3D Cavités résonantes Filtre passe-bande 3D ceramic stereolithography Low pressure molding Machining 3D electromagnetic analysis Resonant cavities Bandpass filter 621.381
2	Geometric approach to multi-scale 3D gesture comparison Ochoa Mayorga, Victor Manuel 11 1900 (has links) The present dissertation develops an invariant framework for 3D gesture comparison studies. 3D gesture comparison without Lagrangian models is challenging not only because of the lack of prediction provided by physics, but also because of a dual geometry representation, spatial dimensionality and non-linearity associated to 3D-kinematics. In 3D spaces, it is difficult to compare curves without an alignment operator since it is likely that discrete curves are not synchronized and do not share a common point in space. One has to assume that each and every single trajectory in the space is unique. The common answer is to assert the similitude between two or more trajectories as estimating an average distance error from the aligned curves, provided that the alignment operator is found. In order to avoid the alignment problem, the method uses differential geometry for position and orientation curves. Differential geometry not only reduces the spatial dimensionality but also achieves view invariance. However, the nonlinear signatures may be unbounded or singular. Yet, it is shown that pattern recognition between intrinsic signatures using correlations is robust for position and orientation alike. A new mapping for orientation sequences is introduced in order to treat quaternion and Euclidean intrinsic signatures alike. The new mapping projects a 4D-hyper-sphere for orientations onto a 3D-Euclidean volume. The projection uses the quaternion invariant distance to map rotation sequences into 3D-Euclidean curves. However, quaternion spaces are sectional discrete spaces. The significance is that continuous rotation functions can be only approximated for small angles. Rotation sequences with large angle variations can only be interpolated in discrete sections. The current dissertation introduces two multi-scale approaches that improve numerical stability and bound the signal energy content of the intrinsic signatures. The first is a multilevel least squares curve fitting method similar to Haar wavelet. The second is a geodesic distance anisotropic kernel filter. The methodology testing is carried out on 3D-gestures for obstetrics training. The study quantitatively assess the process of skill acquisition and transfer of manipulating obstetric forceps gestures. The results show that the multi-scale correlations with intrinsic signatures track and evaluate gesture differences between experts and trainees. 3D gesture comparison Multiscale curvature Curvature-torsion differential geometry complex trajectories quaternion trajectories quaternion projections quaternion metrics 3D trajectory smoothing curvature signature correlations qualitative skill transfer measure medical manipulative gestures nonlinear signatures anisotropic kernel filter curvature numerical stability quaternion smoothing kinematics motor skill transfer curvature signature torsion signature arc-length parameterization tensors Frenet-Serret quaternion framework nonlinear kernel filter geodesic distance finite difference methods differential convolution filter Savitzky-Golay filter least squares curve fitting curvature neighborhood multilevel curvature analysis medical training child bearing simulator robotic simulator motion tracking 3D electromagnetic trackers sequence comparison medical training
3	Geometric approach to multi-scale 3D gesture comparison Ochoa Mayorga, Victor Manuel Unknown Date No description available. 3D gesture comparison Multiscale curvature Curvature-torsion differential geometry complex trajectories quaternion trajectories quaternion projections quaternion metrics 3D trajectory smoothing curvature signature correlations qualitative skill transfer measure medical manipulative gestures nonlinear signatures anisotropic kernel filter curvature numerical stability quaternion smoothing kinematics motor skill transfer curvature signature torsion signature arc-length parameterization tensors Frenet-Serret quaternion framework nonlinear kernel filter geodesic distance finite difference methods differential convolution filter Savitzky-Golay filter least squares curve fitting curvature neighborhood multilevel curvature analysis medical training child bearing simulator robotic simulator motion tracking 3D electromagnetic trackers sequence comparison medical training

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