Sous la direction de SNECMA, un nouveau moteur cryotechnique pour Ariane 5 est en phase de développement. Ce moteur, VINCI, fonctionne à l'oxygène et à l'hydrogène liquides et devra être rallumable en cours de vol. Le transitoire de remplissage d'une cavité intermédiaire par laquelle transite l'oxygène liquide avant d'arriver dans la chambre de combustion s'avère être une étape critique qu'il faut s'efforcer de maîtriser. Cette cavité, appelée dôme LOX, est directement reliée à la chambre de combustion par les injecteurs à oxygène. Des outils numériques sont actuellement en cours de conception : ils permettront à terme de simuler le remplissage de cette cavité dans l'espace. Afin de valider ces outils numériques, un programme expérimental a vu le jour, impliquant SNECMA, le CNES (Centre National d'Etudes Spatiales) et le LEGI (Laboratoire des Ecoulements Géophysiques et Industriels). Il s'agit de mener à bien des expériences « simples » et reproductibles afin de disposer d'une base de données expérimentales qui servira de cas tests pour les simulations. Un banc d'essais expérimental a été progressivement mis en place et instrumenté au LEGI. Le fluide utilisé en substitution de l'oxygène liquide est de l'eau. On a choisi de respecter une similitude du nombre de Weber entre le cas « réel » et les conditions expérimentales. Ce dernier équivaut au rapport des forces d'inertie sur les forces de tension de surface. Deux campagnes d'essais ont été réalisées, dans lesquelles on s'est centré sur l'étude des aspects hydrodynamique du transitoire de remplissage : variation du débit total et des pressions au cours d'un essai, évaluation du taux de vide dans la cavité, visualisation de l'écoulement dans la cavité et en sortie des injecteurs. L'instrumentation à disposition est constituée d'un débitmètre à effet Coriolis, de capteurs de pression, d'une sonde optique, de caméras rapides et d'un laser pour l'imagerie. La première campagne d'essais a visé le remplissage de la cavité en eau seule. Le paramètre de contrôle principal était la pression génératrice de l'écoulement liquide. Dans la deuxième campagne d'essais on injecte simultanément dans la cavité un écoulement d'eau et un écoulement d'air. Cela se rapproche plus des conditions réelles du transitoire de remplissage, au cours duquel la cavité est balayée par un écoulement d'hélium. Le paramètre de contrôle supplémentaire est le débit de gaz initial. Ces campagnes ont également souligné l'importance du profil d'ouverture de la vanne de l'écoulement liquide sur le transitoire de remplissage de la cavité. Ces campagnes d'essais constituent une première étape dans la compréhension du transitoire de remplissage du dôme LOX. Elles ont permis de visualiser la forme de l'écoulement dans la cavité et en sortie des injecteurs et d'identifier certains phénomènes intervenant dans le remplissage de la cavité. En particulier, nous avons mis en évidence l'existence d'un délai de mise en place de l'écoulement par les injecteurs, qui peut être responsable d'un pic de pression dans la cavité au cours du transitoire. L'influence de la fraction gazeuse sur l'écoulement dans les injecteurs a été soulignée mais reste à quantifier de façon précise. La prochaine étape de l'étude concerne les aspects énergétiques du transitoire de remplissage, notamment les transferts thermiques ayant lieu, dans la réalité, entre l'hélium, l'oxygène et les parois du dôme LOX. / Under the supervision of SNECMA, a new cryotechnic engine is being developed for Ariane 5. This engine, named VINCI, uses liquid oxygen and liquid hydrogen as propellant. It must be re-ignitable in flight. The filling transitory phase of an intermediate tank where the liquid oxygen passes through before entering the combustion chamber, has proved to be a very important stage that must be handled. This tank, called LOX dome, is directly linked to the combustion chamber through the oxygen injectors. Numerical tools are currently under development. They will allow to simulate the filling of this tank in the space. In order to validate those numerical tools, an experimental program has been launched. It involves SNECMA, the CNES (Centre National d'Etudes Spatiales : National Centre for Spatial Studies) and the LEGI (Laboratoire des Ecoulements Géophysiques et Industriels : Laboratory of Geophysical and Industrial Flows). Simple and repeatable experiments must be run. They will allow to gather experimental data that will further be used as test cases for the simulations. A test bench has been brought into service step by step at the LEGI, as well as scientific instruments. Water is used in place of liquid oxygen. A similarity of flows based on the Weber number has been chosen between the real case and the experiment. The Weber number measures the relative importance of the fluid inertia compared to its surface tension. Two experimental campaigns have been realized, that have focused on the dynamic aspects of the filling transitory phase : variations of the total flow and of the pressures measured during an experiment, evaluation of the void fraction in the tank, flow visualization in the tank and at the outlet of the injectors. The scientific instrumentation used is made of a Coriolis flow-meter, pressure probes, an optical probe, and high speed cameras with a laser for the flow visualization. The first experimental campaign has studied the tank filling with water only. The main control parameter is the reference pressure of the liquid flow. In the second campaign, both liquid and air flows are simultaneously injected in the tank. It aims at reproducing the real conditions of the filling transitory phase, where helium is injected in the tank with the liquid oxygen. The additional control parameter is the initial gas flow. Those campaigns have shown as well the importance of the valve opening that controls the liquid flow. Those campaigns are a first step in the understanding of the filling transitory phase of the LOX dome. They have permitted to visualize the flow in the tank and at the outlet of the injectors and to point out some important phenomena occurring during the tank filling. In particular, they have highlighted the existence of a delay before the flow can develop through the injectors. This delay can be responsible for a pressure peak in the tank during the transitory phase. The influence of the gas fraction on the flow through the injectors has been underlined as well but still must be accurately quantified. The next step of the study concerns the energetics of the filling transitory phase, especially the thermal transfers that occur between the helium, the oxygen and the walls of the tank.

Le terme stéréopsie renvoie à la sensation de profondeur qui est perçue lorsqu’une scène est vue de manière binoculaire. Le système visuel s’appuie sur les disparités horizontales entre les images projetées sur les yeux gauche et droit pour calculer une carte des différentes profondeurs présentes dans la scène visuelle. Il est communément admis que le système stéréoscopique est encapsulé et fortement contraint par les connexions neuronales qui s’étendent des aires visuelles primaires (V1/V2) aux aires intégratives des voies dorsales et ventrales (V3, cortex temporal inférieur, MT). A travers quatre projets expérimentaux, nous avons étudié comment le système visuel utilise la disparité binoculaire pour calculer la profondeur des objets. Nous avons montré que le traitement de la disparité binoculaire peut être fortement influencé par d’autres sources d’information telles que l’occlusion binoculaire ou le son. Plus précisément, nos résultats expérimentaux suggèrent que : (1) La stéréo de da Vinci est résolue par un mécanisme qui intègre des processus de stéréo classiques (double fusion), des contraintes géométriques (les objets monoculaires sont nécessairement cachés à un œil, par conséquent ils sont situés derrière le plan de l’objet caché) et des connaissances à priori (une préférence pour les faibles disparités). (2) Le traitement du mouvement en profondeur peut être influencé par une information auditive : un son temporellement corrélé avec une cible définie par le mouvement stéréo peut améliorer significativement la recherche visuelle. Les détecteurs de mouvement stéréo sont optimalement adaptés pour détecter le mouvement 3D mais peu adaptés pour traiter le mouvement 2D. (3) Grouper la disparité binoculaire avec un signal auditif dans une dimension orthogonale (hauteur tonale) peut améliorer l’acuité stéréo d’approximativement 30% / Stereopsis refers the perception of depth that arises when a scene is viewed binocularly. The visual system relies on the horizontal disparities between the images from the left and right eyes to compute a map of the different depth values present in the scene. It is usually thought that the stereoscopic system is encapsulated and highly constrained by the wiring of neurons from the primary visual areas (V1/V2) to higher integrative areas in the ventral and dorsal streams (V3, inferior temporal cortex, MT). Throughout four distinct experimental projects, we investigated how the visual system makes use of binocular disparity to compute the depth of objects. In summary, we show that the processing of binocular disparity can be substantially influenced by other types of information such as binocular occlusion or sound. In more details, our experimental results suggest that: (1) da Vinci stereopsis is solved by a mechanism that integrates classic stereoscopic processes (double fusion), geometrical constraints (monocular objects are necessarily hidden to one eye, therefore they are located behind the plane of the occluder) and prior information (a preference for small disparities). (2) The processing of motion-in-depth can be influenced by auditory information: a sound that is temporally correlated with a stereomotion defined target can substantially improve visual search. Stereomotion detectors are optimally suited to track 3D motion but poorly suited to process 2D motion. (3) Grouping binocular disparity with an orthogonal auditory signal (pitch) can increase stereoacuity by approximately 30%

Installé au cœur de l'interféromètre du Very Large Telescope (le VLTI, situé au sommet du Mont Paranal, dans le nord du Chili), l'instrument VINCI permet de recombiner la lumière infrarouge de deux télescopes séparés de manière cohérente. Il ouvre ainsi un accès vers la très haute résolution angulaire (quelques millisecondes d'angle), et des programmes de recherche novateurs dans des domaines aussi divers que la physique stellaire, les disques protoplanétaires ou bien encore l'étude des exoplanètes. Mon travail de thèse sur l'instrument VINCI a porté sur sa conception, en particulier la définition fonctionnelle de son logiciel d'exploitation, son installation au sommet du Mont Paranal et ses premières observations scientifiques. Le principe de fonctionnement et les performances de cet instrument sont décrits dans la première partie de ce document.<br /> Dans une seconde partie, j'aborde l'étude des étoiles variables Céphéides par interférométrie. Ces étoiles pulsantes jouent un rôle primordial dans l'estimation des distances astronomiques depuis qu'il a été établi que leur période de variation était liée à leur luminosité intrinsèque par la célèbre relation période-luminosité. Leur observation photométrique permet donc de calculer directement leur distance. Toutefois, notre connaissance du point zéro de cette relation est encore imparfaite, car elle repose sur la mesure des distances aux Céphéides galactiques les plus proches, encore mal connues. La très haute résolution angulaire apportée par l'instrument VINCI et le VLTI permettra bientôt l'étude fine de la pulsation de ces étoiles. Par la mesure simultanée de la vitesse radiale de pulsation et de la variation du diamètre angulaire de l'étoile, il sera possible de calculer directement la distance aux Céphéides les plus proches, et donc d'étalonner la relation période-luminosité. L'enjeu de ce programme : la calibration de cette relation avec une précision de 0,01 magnitude, soit un gain d'un facteur dix par rapport à notre connaissance actuelle.<br /> Au-delà de ce programme fondamental, je décris également les possibilités offertes par VINCI dans le domaine de l'étude des étoiles naines de la séquence principale, notamment de type solaire (avec application au couple d'étoiles Alpha Centauri A et B), et j'aborde brièvement l'étude des exoplanètes.

I följande uppsats så analyseras alternativa och ofta uppseendeväckande tolkningar av kända konstverk, närmare bestämt interpretationer som menar sig peka på dolda budskap från konstnären. Bildtolkningarna granskas i ljuset av spårsökande paradigm samt det skelett som utgör konspirationsteorier. Konspirationsteorier handlar ofta om makt och politik, men det hindrar inte att strukturen som upprätthåller dessa teorier kan sprida sig till och florera även inom andra ämnen. Undersökningen analyserar vad som händer med bildtolkningarna när de sätts i relation till teorier om konspirationsteorier. Resultatet visar att bildtolkningarna i hög grad är formulerade som samt bygger upp sin bevisning i enlighet med konspirationsteorier, och det spårsökande paradigmet är ständigt närvarande med ett fokus på detaljer för att bättre förstå helheten.

The da Vinci Surgical System is one of the most established robot-assisted surgery device commended for its dexterity and ergonomics in minimally invasive surgery. Conversely, it inherits disadvantages which are lack of autonomy and haptic feedback. In order to address these issues, this work proposes an industry-inspired solution to the field of force control in medical robotics. This approach contributes to shared autonomy by developing a controller for cooperative object manipulation with force tracking utilizing available manipulators and force feedback. To achieve simultaneous position and force tracking of the object, master and slave manipulators were assigned then controlled with Cartesian position control and impedance control respectively. Because impedance control requires a model-based feedforward compensation, we identified the lumped base parameters of mass, inertias, and frictions of a three degree-of-freedom double four-bar linkage mechanism with least squares and weighted least squares regression methods. Additionally, semidefinite programming was used to constrain the parameters to a feasible physical solution in standard parameter space. Robust stick-slip static friction compensation was applied where linear Viscous and Coulomb friction was inadequate in modeling the prismatic third joint. The Robot Operating System based controller was tested in RViz to check the cooperative kinematics of up to three manipulators. Additionally, simulation with the dynamic engine Gazebo verified the cooperative controller applying a constant tension force on a massless spring-damper virtual object. With adequate model feedback linearization, the cooperative impedance controller tested on the da Vinci Research Kit yielded stable tension force tracking while simultaneously moving in Cartesian space. The maximum force tracking error was +/- 0.5 N for both a compliant and stiff manipulated object.

Made available in DSpace on 2015-03-05T18:25:03Z (GMT). No. of bitstreams: 0 Previous issue date: 27 / Nenhuma / Este trabalho trata do processo de circulação polêmico-crítica em torno do filme O Código Da Vinci. A pesquisa se desenvolve na análise a partir do conceito de Sistema de Resposta Social sobre a mídia, compreendendo a formação de um espaço polêmico. Foram analisados 17 tipos de materiais diversificados, assumidos como críticos, que constroem suas perspectivas a partir de diversos campos sociais, e se expressam em jornais, revistas, documentários, blogs e sites que trataram a temática do filme. O principal eixo da análise está na disputa de um capital simbólico religioso entre campos sociais, disputa que ocorre dentro de canais midiáticos. A disputa de falas é o argumento para a defesa de um campo que se constitui a partir das diversas falas: o campo polêmico. Para isso a análise observa parâmetros, no material empírico, segundo os quais os participantes instauram e dão forma à polêmica.

Base Teórica: A histerectomia ainda é um procedimento cirúrgico frequente. Nos últimos 25 anos, muitos esforços foram feitos para reduzir o número de histerectomias abdominais, como o avanço tecnológico, que permitiu cirurgias menos invasivas. Visando ampliar o uso da cirurgia minimamente invasiva, foi desenvolvida a cirurgia robótica, com a vantagem de facilitar o uso da laparoscopia proporcionando movimentos mais ergonômicos e precisos. Apesar de ser tecnologia recente e do alto custo, vem ganhando cada vez mais espaço na prática clínica. Dados sobre tempo cirúrgico e tempo de internação pós-operatória tem sido alvo de várias publicações, uma vez que afetam os custos do procedimento. Objetivo: O presente projeto visa à documentação da experiência inicial do Hospital de Clínicas de Porto Alegre na realização da histerectomia robótica, e comparação dos seus dados com outras vias de histerectomia já realizados no nosso meio. Métodos: Foi realizado estudo caso-controle para comparação de dados pré-operatórios, operatórios (como tempo cirúrgico total e sangramento) e pós-operatórios (tempo de recuperação pós-operatória, complicações, dor nas primeiras 24 horas após a cirurgia), em 80 pacientes, submetidas à histerectomia para tratamento de patologias uterinas benignas. Nós incluímos quatro grupos de pacientes: robótico, vaginal, abdominal e laparoscópico. O grupo robótico foi composto pelas primeiras 20 cirurgias realizadas em nosso hospital, e os grupos controle foram selecionados retrospectivamente a partir da data da última cirurgia robótica, constituindo uma amostragem não probabilística. Também foi realizado estudo transversal utilizando apenas as pacientes submetidas à cirurgia robótica em nosso serviço, para fins de documentação de nossa experiência inicial. Resultados: O grupo robótico foi responsável pelo maior tempo cirúrgico total (180,7 minutos), e pelo menor tempo de recuperação pós-operatória (23,7 horas), entre os quatro grupos. Não houve diferença entre os grupos na análise do sangramento transoperatório e das complicações pós-operatórias. Dados analisados sobre a dor pós-operatória não diferiram entre os grupos. No estudo transversal, foi demonstrada curva de aprendizado em tempo de docking e undocking, e houve correlação forte entre tempo cirúrgico total e índice de massa corporal da paciente. Conclusão: Análise do tempo cirúrgico total e do tempo de recuperação pós-operatória são relevantes, pois podem ser ferramentas necessárias para redução dos custos da cirurgia robótica. Nossa experiência inicial demonstra curva de aprendizado em alguns aspectos. / Background: Hysterectomy is a frequent surgical procedure. In the last 25 years, many efforts have been made to reduce the number of abdominal hysterectomies, such as the technological advances, which allowed less invasive procedures. Aiming to increase the use of minimally invasive surgery, the robotic surgery was developed, which advantage of more precise and ergonomic movements than laparoscopy. Although it is a recent and expensive technology, robotic surgery is gaining more space in clinical practice. Data from Total Surgical Time and Time of Postoperative Recovery has been target of publications, once they can affect the costs. Objective: The purpose of this study is to compare the surgical outcomes of patients undergoing robotic hysterectomy for benign cases to patients undergoing another types of hysterectomy performed in our institution. Methods: It was performed a case-control study to compare pre-operative, operative (as Total Surgical Time and bleeding) and postoperative (Time of Postoperative Recovery, complications, and pain at the first 24 hours after the surgery) in 80 patients undergoing hysterectomy for treatment of various benign uterine conditions. We have included four groups of patients: robotic, vaginal, abdominal and laparoscopic. The robotic group was composed by the first twenty patients undergoing robotic hysterectomy at our hospital, and the control groups were retrospectively selected from the date of the last robotic surgery, constituting a non-probabilistic sample. We also performed a crosssectional study with the 20 patients of robotic group, to document our initial experience. Results: The robotic group was responsible for the longer Total Surgical Time (180.7 minutes), and for the shortest Time of Postoperative Recovery (23.7 hours) among the four groups. There were no difference between the groups in analysis of estimated blood loss and postoperative complications. Data related to postoperative pain showed no difference between the groups. At cross-sectional study, it was demonstrated learning curve of docking and undocking times, and was found a strong correlation between Total Surgical Time and body mass index. Conclusion: Analysis of Total Surgical Time and Time of Postoperative Recovery are relevant, because they can be necessary tools to reduce the costs of robotic surgery. Our initial experience demonstrated learning curve in some ways.

<p>Major part of the current work describes the development of the update methodology for onedimensional code (TML) currently used at Volvo Aero Corporation during turbine design process. The methodology is then applied and tried out in a general engine analysis (GESTPAN).</p>

Major part of the current work describes the development of the update methodology for onedimensional code (TML) currently used at Volvo Aero Corporation during turbine design process. The methodology is then applied and tried out in a general engine analysis (GESTPAN).

Base Teórica: A histerectomia ainda é um procedimento cirúrgico frequente. Nos últimos 25 anos, muitos esforços foram feitos para reduzir o número de histerectomias abdominais, como o avanço tecnológico, que permitiu cirurgias menos invasivas. Visando ampliar o uso da cirurgia minimamente invasiva, foi desenvolvida a cirurgia robótica, com a vantagem de facilitar o uso da laparoscopia proporcionando movimentos mais ergonômicos e precisos. Apesar de ser tecnologia recente e do alto custo, vem ganhando cada vez mais espaço na prática clínica. Dados sobre tempo cirúrgico e tempo de internação pós-operatória tem sido alvo de várias publicações, uma vez que afetam os custos do procedimento. Objetivo: O presente projeto visa à documentação da experiência inicial do Hospital de Clínicas de Porto Alegre na realização da histerectomia robótica, e comparação dos seus dados com outras vias de histerectomia já realizados no nosso meio. Métodos: Foi realizado estudo caso-controle para comparação de dados pré-operatórios, operatórios (como tempo cirúrgico total e sangramento) e pós-operatórios (tempo de recuperação pós-operatória, complicações, dor nas primeiras 24 horas após a cirurgia), em 80 pacientes, submetidas à histerectomia para tratamento de patologias uterinas benignas. Nós incluímos quatro grupos de pacientes: robótico, vaginal, abdominal e laparoscópico. O grupo robótico foi composto pelas primeiras 20 cirurgias realizadas em nosso hospital, e os grupos controle foram selecionados retrospectivamente a partir da data da última cirurgia robótica, constituindo uma amostragem não probabilística. Também foi realizado estudo transversal utilizando apenas as pacientes submetidas à cirurgia robótica em nosso serviço, para fins de documentação de nossa experiência inicial. Resultados: O grupo robótico foi responsável pelo maior tempo cirúrgico total (180,7 minutos), e pelo menor tempo de recuperação pós-operatória (23,7 horas), entre os quatro grupos. Não houve diferença entre os grupos na análise do sangramento transoperatório e das complicações pós-operatórias. Dados analisados sobre a dor pós-operatória não diferiram entre os grupos. No estudo transversal, foi demonstrada curva de aprendizado em tempo de docking e undocking, e houve correlação forte entre tempo cirúrgico total e índice de massa corporal da paciente. Conclusão: Análise do tempo cirúrgico total e do tempo de recuperação pós-operatória são relevantes, pois podem ser ferramentas necessárias para redução dos custos da cirurgia robótica. Nossa experiência inicial demonstra curva de aprendizado em alguns aspectos. / Background: Hysterectomy is a frequent surgical procedure. In the last 25 years, many efforts have been made to reduce the number of abdominal hysterectomies, such as the technological advances, which allowed less invasive procedures. Aiming to increase the use of minimally invasive surgery, the robotic surgery was developed, which advantage of more precise and ergonomic movements than laparoscopy. Although it is a recent and expensive technology, robotic surgery is gaining more space in clinical practice. Data from Total Surgical Time and Time of Postoperative Recovery has been target of publications, once they can affect the costs. Objective: The purpose of this study is to compare the surgical outcomes of patients undergoing robotic hysterectomy for benign cases to patients undergoing another types of hysterectomy performed in our institution. Methods: It was performed a case-control study to compare pre-operative, operative (as Total Surgical Time and bleeding) and postoperative (Time of Postoperative Recovery, complications, and pain at the first 24 hours after the surgery) in 80 patients undergoing hysterectomy for treatment of various benign uterine conditions. We have included four groups of patients: robotic, vaginal, abdominal and laparoscopic. The robotic group was composed by the first twenty patients undergoing robotic hysterectomy at our hospital, and the control groups were retrospectively selected from the date of the last robotic surgery, constituting a non-probabilistic sample. We also performed a crosssectional study with the 20 patients of robotic group, to document our initial experience. Results: The robotic group was responsible for the longer Total Surgical Time (180.7 minutes), and for the shortest Time of Postoperative Recovery (23.7 hours) among the four groups. There were no difference between the groups in analysis of estimated blood loss and postoperative complications. Data related to postoperative pain showed no difference between the groups. At cross-sectional study, it was demonstrated learning curve of docking and undocking times, and was found a strong correlation between Total Surgical Time and body mass index. Conclusion: Analysis of Total Surgical Time and Time of Postoperative Recovery are relevant, because they can be necessary tools to reduce the costs of robotic surgery. Our initial experience demonstrated learning curve in some ways.