Made available in DSpace on 2014-10-09T12:43:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:01Z (GMT). No. of bitstreams: 1 06779.pdf: 6662459 bytes, checksum: 5a5ae589785a8bad523a922f578319f8 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Neste trabalho, estudamos a ação dos grupos split metacíclicos \'D IND. (2h+1) POT. 2 nas esferas. Encontramos uma região fundamental dos espaços quocientes, chamados de Formas Espaciais Esféricas Metacíclicas, que foi utilizada para construirmos um conveniente complexo de cadeias destas formas com o qual calculamos o anel de cohomologia e a torção de Reidemeister. Obtivemos também uma relação entre as diferentes torções encontradas / In this work, we study the action of the split metacyclic groups \'D IND. (2h+1) POT. 2 on the spheres. We find a fundamental domain of the quotient spaces, called Metacyclic Spherical Space Forms. Through this region we have built a convenient chain complex of these spaces and we used it to calculate their cohomology ring and Reidemeister torsion. We obtained also a relation between the different torsions found

Le travail mené dans cette thèse est une contribution au développement mécatronique d'interfaces haptiques pour un système de télé-opération dédié aux applications médicales du type chirurgie mini-invasive. Dans un premier temps, nous avons mené une évaluation d'une interface « maître » existante, ayant une architecture parallèle sphérique et développée au sein de l'équipe robotique de l'Institut PPRIME. Cette évaluation a montré la présence de singularités, en particulier des singularités parallèles, à l'intérieur de l'espace du travail de l'interface. La présence de singularités altère le comportement cinématique en amplifiant les erreurs de résolution du modèle géométrique direct d'une part et les couples actionneurs lors du retour d'effort d'autre part. Dans un deuxième temps, différentes approches ont été proposées pour résoudre les problèmes liés à la présence des singularités. La première approche a consisté à utiliser la redondance de capteurs et la redondance d'actionneurs pour palier à ces effets dans la structure existante. Dans la seconde approche, nous avons proposé une nouvelle architecture mécanique optimale qui élimine les singularités présentent dans l'espace de travail. Les résultats obtenus, avec cette nouvelle structure à travers les essais expérimentaux réalisés sur le prototype, sont conformes aux objectifs fixés. Les deux interfaces haptiques ont été utilisées pour contrôler avec succès un robot dédié à la chirurgie mini-invasive. Le comportement du système global « robot esclave interface haptique » ouvre des perspectives prometteuses aussi bien pour de futures études scientifiques que pour un transfert industriel. / A contribution for a development of haptic devices for tele-operation system is presented in this thesis. This device is dedicated for medical applications such as minimally invasive surgery tasks. In one first step, an evaluation of the existing master device is carried out. This device has a spherical parallel architecture and has been developed within the robotics team of PPRIME Institute. The evaluation of this device has shown the presence of parallel singularities located in its workspace. This singularity alters the kinematic behavior of the structure by amplifying the errors in solving the forward kinematics and amplifying the actuator torques for the haptic feedback. In a second step, different approaches have been proposed to solve the problems related to the presence of the singularities. The first approach consists in using redundancy of sensors and actuators for the existing structure in order to overcome the effects of singularities. In the second approach, we have proposed a new optimal mechanical architecture that eliminates the singularity. The results obtained with this new structure through the experimental testing of the prototype, are in accordance with the expected ones. The two haptic devices have been used to successfully control a robot dedicated to minimally invasive surgery. The behavior of the overall system "robot and haptic device" opens up promising prospects for future studies as well as for industrial transfer.

Doctor of Philosophy / Department of Mechanical and Nuclear Engineering / Liang-Wu Cai / A computational system is built for conducting deterministic simulations of three-dimensional multiple scattering of elastic waves by spherical inclusions. Based on expansion expression of elastic wave fields in terms of scalar and vector spherical harmonics, analytically exact solutions of single scattering and multiple scattering are obtained, implemented and verified. The verification is done by using continuities of displacement and surface traction at the interface between an inclusion and host medium, energy conservation and published results. The scatterer polymerization methodology is extended to three-dimensional multiple scattering solution. By using this methodology, an assemblage of actual scatterers can be treated as an abstract scatterer. This methodology is verified by using different approaches, with or without scatterer polymerization, to solve a physically the same multiple scattering problem. As an application example, band gap formation process for elastic wave propagation in cubic lattice arrangements of spherical scatterers is observed through a series of numerical simulations. Along the direction of the incident wave, scatterer arrangements are viewed as comprising layers of scatterers, within which scatterers form a square grid. Starting from one layer and by increasing the number of layers, near-field forward wave propagation spectra are computed as the number of layers increases. These simulations also demonstrates that the computational system has the capability to simulate multiple scattering solutions of elastic waves in three-dimension.

This work is concerned with two different problems in harmonic analysis, one on the Heisenberg group and other on Rn, as described in the following two paragraphs respectively. Let Hn be the (2n + 1)-dimensional Heisenberg group, and let K be a compact subgroup of U(n), such that (K, Hn) is a Gelfand pair. Also assume that the K-action on Cn is polar. We prove a Hecke-Bochner identity associated to the Gelfand pair (K, Hn). For the special case K = U(n), this was proved by Geller, giving a formula for the Weyl transform of a function f of the type f = Pg, where g is a radial function, and P a bigraded solid U(n)-harmonic polynomial. Using our general Hecke-Bochner identity we also characterize (under some conditions) joint eigenfunctions of all differential operators on Hn that are invariant under the action of K and the left action of Hn . We consider convolution equations of the type f * T = g, where f, g ε Lp(Rn) and T is a compactly supported distribution. Under natural assumptions on the zero set of the Fourier transform of T , we show that f is compactly supported, provided g is.

The master thesis maps the state of the art of visual object tracking in panoramic 360° video. The thesis aims to reveal the main problems related to visual object tracking and moreover focuses on their solution in panoramic videos. In the study of the existing approaches was found that very few solutions of visual object tracking in equirectangular projection of panoramic video have been implemented so far. This thesis therefore presents two improvements of object tracking methods that are based on the adaptation of equirectangular frames. In addition, this thesis brings the manually created dataset of panoramic videos with more than 9900 annotations. Finally the detailed evaluation of 12 well known and state of the art trackers has been performed for this new dataset.

JEŽ Marek: Technology of thrust bearing steel cages production . Diploma assert of daily magisteral´s studies, study programme – Industry. The branch manufactoring technology, 2 end form, level 2 – summer semester, study group 50 / 51, academical year 2007 / 2008. FSI of Brno University of Technology, department of forming and plastics, May 2008, 78 pages, 54 pictures, 6 supplements. The main theme of the Diploma Theses is the technology of production of tin cages for axial spherical-roller bearings. The given matter includes the production of tin cages for axial spherical-roller bearings – by traction, cutting, punching and calibration. For the chosen representative, i.e. bearing with marking 29 336 M I suggest the substitution of tin cage instead of the brass one. The component (cage) is made of the sheet iron 11 300 of 4 mm thickness, the basic semi product is the sheet panel with the size of 360 x 4 x 3000 mm. In solving the given matter, it is started from the fact that the current state of the cage is still under development. The aim of the Diploma Thesis is to choose the representative, suggest the appropriate technological progress, proposing the engineering design of functional parts of the tool for punching the holes/windows including the necessary calculations and workshop graphical documentation.

This thesis deals with the analysis of properties of hard coatings and wear resistance PVD coated technology. It focuses on the preparation, execution and evaluation of test coatings on the front ball milling cutter.

The thesis deals with the design of the device that is used to improve the quality of the surface of spherical rollers. Spherical rollers are used for the measuring of the conditions in the EHD contact. The high roughness and waviness of the spherical rollers’ surface is a problem. Several machining methods are described in the theoretical part. The overview in theoretical part has been used for choice of the machining methods (lapping and abrasive polishing). The spherical rollers‘ machining system, its construction, electronics and control systems are described in the next section. The last part is focused on testing of assembled device, and on checking its functionality. The desired roughness of the spherical rollers' surface, suitable for successful interferometric measurement, was achieved by combining the selected machining methods. The roughness and waviness achieved was Ra0.01 micron Wa0.022 microns.

A caractérisation de l’écoulement, du transfert de chaleur et de masse lors du déplacement de gouttelettes de diamètre inferieur au millimètre dans un milieu extérieur font l’objet de notre étude. La première partie présente l’état de l’art des connaissances théoriques et expérimentales des comportements aérodynamiques ainsi que les mécanismes de transfert thermiques et massiques intervenant entre une phase dispersée et une phase continue. La deuxième partie est consacrée à l’étude du phénomène d’évaporation d’une gouttelette mono-dispersée en chute libre dans l’air. Pour cela, nous avons réalisé un dispositif expérimental. Les mesures, nous permettent de prédire l’évaporation de la gouttelette en fonction des caractéristiques physico-chimiques et de l’hygrométrie du milieu extérieur. Pour la modélisation du transfert de chaleur et de masse nous avons utilisé un modèle simple qui tient en compte du couplage entre le mouvement et les phénomènes de transferts, validé dans une précédente étude au sein du laboratoire. Un bon accord est observé. La troisième partie traite de la simulation numérique de l’interaction entre les particules sphériques dans un régime laminaire. Tout d’abord, nous avons proposé et validé un modèle simple qui ne tient pas en compte des phénomènes d’interaction. Les résultats obtenus sont en concordance avec la littérature. Par la suite, nous avons étudié l’interaction entre trois particules identiques et co-alignées. Ce modèle tient compte de la nature de la particule, du nombre du Reynolds et de la distance de séparation. Nous avons validé ce travail par une comparaison avec une étude précédente que nous avons généralisé. La dernière partie est cernée sur l’étude de la dispersion des gouttelettes dans un écoulement turbulent homogène et isotrope. Pour cela, nous avons proposé un modèle Lagrangien de suivi des trajectoires. La production de la turbulence est assurée par une condition de turbulence de grille. Nous avons considéré que les caractéristiques moyennes de l’écoulement fluide sont connues. La sélection des fluctuations de vitesse turbulente est assurée par une méthode probabiliste gaussienne que nous avons développée. La fluctuation est conservée durant un certain temps lié à turbulence, elle est renouvelée au cours du calcul. Ce renouvellement est donné par le temps caractéristique de turbulence. / The characterization of flow, mass and heat transfer during moving droplets of diameter inferior to the millimetre makes the object of our study. In the first part, we present the theoretical and experimental knowledge. In the second part, we studied the evaporation of a free falling droplet in the air. In the third part, we make a simulation of the interaction between the spherical particles in laminar flow. This model takes into account the nature of the particle, the Reynolds number and the separation distance. In the last part, we study the dispersion of droplets in a homogeneous and isotropic turbulent flow.