The potential role of lower limb blood pooling in reducing venous return to the heart during orthostasis and elevated venous pressure is investigated. This study compares lower limb capacitance, microvascular filtration, and peripheral resistance between a group of highly trained endurance athletes and a group of their sedentary peers. Seven endurance trained males were selected between the ages of 23-33 [(29.1 4.1 yr), mean SD]. The subjects weekly cycling mileage ranged from 80 to 150 miles per week with an average of 125 8.5 miles/week. Nine healthy, age-matched sedentary subjects (25.8 4.8 yr.) were selected for the control group, based upon their reporting they had not participated in repeated lower-body or cardiovascular exercise in the months prior to their study. Results show that both subject groups had similar calf venous capacitances, rates of capillary fluid filtration, and local flow shunting (vascular resistance change) in response to venous thigh occlusion and 70 head-up tilt (HUT). The only significant difference found between groups was the cyclist groups smaller rise in heart rate in response to HUT. The findings of this study suggest that cyclists are not predisposed to orthostatic intolerance due to any changes in lower limb function.

In the modern day, recognition and tracking of face or the iris is potentially one of the most powerful ways of differentiating between an authentic person and an imposter. Our method uses stereo vision to track the 3-Dimensional coordinates of a target equivalent to a person’s eyes and using a pan-tilt unit we target these areas for additional processing such as iris or facial imaging. One of the most important parts involved in tracking is the way the pan-tilt unit is calibrated. There have been techniques in the past where PTZ (Pan-tilt-zoom) digital camera has been used and calibrated using self calibration techniques involving a checker board calibration grid but the tracking error was found to be large in these techniques. We introduce a more accurate form of calibration of the pantilt unit using photogrammetric calibration technique and view the pan-tilt unit as an emulation of a Pinhole Lens Model to detect and track the target. The system is demonstrated on ideal targets.

Multi-Object Adaptive Optics promises to be a useful tool for the upcoming class of Extremely Large Telescopes. Like current adaptive optics systems, MOAO systems compensate optical aberrations caused by atmospheric turbulence, but with the added benefit of being able to compensate multiple portions of a telescope’s field at the same time. To ensure the success of the eventual MOAO systems built for the ELTs, several demonstrator instruments have been designed and tested on current telescopes. Raven is one of these demonstrators, designed by the University of Victoria Adaptive Optics Lab for the Subaru 8.2 meter telescope to feed the InfraRed Camera and Spectrograph. Raven corrects the light of two science targets using wavefront information from three natural guide stars, and a single laser guide star. The topic of this thesis is the design and implementation of Raven’s tip/tilt compensation system, used to stabilize the output image positions on IRCS’s 0.140” slit. Tip/tilt correction of the science targets is done using a combination of motorized pick-off arms, piezoelectric tip/tilt platforms, and deformable mirrors. Through digital filtering and calibration, it is shown that these actuators are able to collectively keep the output science images stationary during simulated laboratory observations. A performance reduction due to residual tip/tilt errors is expected to be less than 5%. Raven goes on-sky in mid-2014, and it will be the first MOAO instrument to attempt scientific observations. / Graduate / 0548 / 0606

Element test results reported in the literature under both triaxial and plane strain conditions indicate that loose saturated granular specimens can experience softening instability at stress ratios lower than what might otherwise be expected given the critical state friction angle of the soil. The region of potential softening instability in stress-space is often explained using the framework of the instability line. This phenomenon is particularly relevant to shallow slopes of 1 to 2 m depth. However, the practical realities of sample preparation for triaxial testing make performing tests below 20 to 30 kPa of confining stress exceptionally difficult. In this thesis, the development of a centrifuge tilt-table test device is described which aims to test the behaviour of loose granular slopes under stress paths of increasing slope inclination or increasing pore water pressure. A system of instrumentation including pore pressure transducers, inclinometers, displacement transducers, and high-resolution cameras was designed to monitor the behaviour of the slope model. The development of a system to provide a controlled groundwater level within the slope model proved to be particularly challenging. The results of two competing design concepts are presented for the water boundary condition and discussed. The centrifuge tilt-table is used to compare the physical response of a slope to the behaviour predicted by the infinite slope and softening instability models using scale model centrifuge testing. If softening instability is a rigorous concept, it should be the primary observed failure mechanism as it will occur at a stress state below the failure line. Tests were performed on loose Ottawa F110 sand at 1g, 20g and 40g and 60g. Deviatoric strain-softening was observed in loose dry sand. The softening instability event resulted in a rapid increase in shear strain at constant shear stress while the soil was at a stress state below the failure envelope. Any soil that can experience softening instability (i.e. granular, loose, saturated, and behaves undrained) will undergo two failures: one caused by deviatoric strain-softening (softening instability) and a second caused by shear failure at a larger slope angle. / Thesis (Master, Civil Engineering) -- Queen's University, 2014-04-29 22:01:36.786

Pen-based interactions are becoming widely popular on a variety of devices, including tabletPCs, mobile devices and tabletop systems. The digital pens and tablets have evolved considerably and served users in creative industries. A digital pen can sense various auxiliary inputs, such as tilt, pressure and roll. Researchers have explored properties of each channel in isolation of another. Since the human wrist and fingers can operate multiple input channels simultaneously, a natural progression warrants examination of controllability when these channels are operated simultaneously. In this thesis, I explore a class of interaction techniques, a-coord input, which requires users to control two auxiliary channels simultaneously. Through experiments, I explore the design space of a-coord input and investigate the effect of changing the order in which the channels are combined. Furthermore, I investigate its effectiveness for discrete and continuous selection tasks. Finally, this thesis shows the value of a-coord input through several applications.

Multi-Object Adaptive Optics promises to be a useful tool for the upcoming class of Extremely Large Telescopes. Like current adaptive optics systems, MOAO systems compensate optical aberrations caused by atmospheric turbulence, but with the added benefit of being able to compensate multiple portions of a telescope’s field at the same time. To ensure the success of the eventual MOAO systems built for the ELTs, several demonstrator instruments have been designed and tested on current telescopes. Raven is one of these demonstrators, designed by the University of Victoria Adaptive Optics Lab for the Subaru 8.2 meter telescope to feed the InfraRed Camera and Spectrograph. Raven corrects the light of two science targets using wavefront information from three natural guide stars, and a single laser guide star. The topic of this thesis is the design and implementation of Raven’s tip/tilt compensation system, used to stabilize the output image positions on IRCS’s 0.140” slit. Tip/tilt correction of the science targets is done using a combination of motorized pick-off arms, piezoelectric tip/tilt platforms, and deformable mirrors. Through digital filtering and calibration, it is shown that these actuators are able to collectively keep the output science images stationary during simulated laboratory observations. A performance reduction due to residual tip/tilt errors is expected to be less than 5%. Raven goes on-sky in mid-2014, and it will be the first MOAO instrument to attempt scientific observations. / Graduate / 0548 / 0606

In 1967 the US Air Force solicited proposals for ``low-disc-loading [Vertical Takeoff and Landing] configurations suitable for high speed flight.' Bell Helicopter elected to respond with a proposal after initial analysis on configurations including a stopped edgewise disc and a trail rotor. They concluded that a folding proprotor design would best meet the requirements laid forth. Initial analysis work began on this folding proprotor (stop-fold) design in the same year and concluded in 1972 with a full scale 25 foot diameter pylon and rotor assembly wind tunnel test at the NASA-Ames Large Scale Wind Tunnel. The project was concluded at this point and never resulted in a production or research aircraft. The original proposed stop-fold tiltrotor design by Bell Helicopter allowed for vertical takeoff and landing, a transition sequence rotating the pylon rotor assembly from helicopter to airplane mode, a conversion sequence during which the rotor stopped and blades folded along the pylon, and a transition from prop thrust to auxiliary jet engine power while the rotor was being stopped. This configuration effectively removes the high-speed restraints typical of a prop-driven aircraft and instead opens a flight envelope comparable to a fixed-wing jet. This project entails both the simulation and basic analysis of the stop-fold concept with special attention to frequency responses and potential coupling between modes.

O objetivo deste trabalho é avaliar a distribuição de pressão, no assento e no encosto, relacionada à variação do ângulo de tilt da cadeira de rodas e contribuir para uma melhor prescrição de sistemas de adequação postural na posição sentada. Para tanto, estruturou-se uma pesquisa descritiva composta por procedimentos tipo estudos de casos. A pesquisa foi direcionada a usuários com diagnóstico de Paralisia Cerebral, nível motor IV e V (GMFCS) e que necessitam de um melhor posicionamento no sentar. Para as análises, foram utilizadas as almofadas pré-fabricadas que acompanham a cadeira em conjunto com as técnicas de mapeamento de pressão e termografia. As principais variáveis analisadas foram a distribuição de pressão e de temperatura, por meio de diagramas, bem como foram avaliados estatisticamente os respectivos valores médios. Os resultados demonstraram que nenhum dos 15 usuários avaliados apresentou postura adequada no sistema de assento e encosto padrão da cadeira de rodas. A distribuição da pressão mostrou-se inadequada, em geral, com picos importantes atribuídos à falta de estabilidade da pelve e do tronco. A utilização de cadeira de rodas com tilt é indicada, porém, faz-se necessária uma cuidadosa análise desse ângulo, bem como dos suportes de apoio ajustáveis às necessidades individuais. Recomenda-se a personalização das almofadas de assento, de encosto e de apoio de cabeça, através da moldagem do corpo do usuário. Destaca-se que os dados obtidos neste estudo podem auxiliar na identificação das necessidades dos usuários e, consequentemente, no projeto de assentos para cadeira de rodas, proporcionando maior qualidade de vida aos usuários. / The objective of this study is to evaluate the pressure distribution on the seat and backrest related to the angle variations of the wheelchair tilt-in-space. It also aims to contribute to a more suitable prescription of positioning systems. In order to do that, the descriptive research was structured by using case studies. The survey was targeted to users that had been diagnosed with cerebral palsy, gross motor function (GMFCS) IV and V who are need of a more appropriate wheelchair seating. Furthermore, for the analysis, the prefabricated chair cushions, the pressure mapping techniques and thermography had been used. The main variables analyzed were the distribution of pressure and temperature, through diagrams, which were statistically evaluated mean values. The results showed that none of the 15 members evaluated had an adequate posture in the standard seating system. The pressure distribution proved inadequate in general with important peaks attributed to the lack of stability of the pelvis and trunk. The use of the tilting wheelchair is recommended. However, it is required a more careful analysis of this angle, as well as the adjustable support brackets to individual needs. It is recommended to customize the seat cushions, backrest and headrest, through the user's body contour. It is noteworthy that the data obtained in this study can help identify the needs of users and consequently the seat design for a wheelchair, providing a higher quality of life to the users.

O objetivo deste trabalho é avaliar a distribuição de pressão, no assento e no encosto, relacionada à variação do ângulo de tilt da cadeira de rodas e contribuir para uma melhor prescrição de sistemas de adequação postural na posição sentada. Para tanto, estruturou-se uma pesquisa descritiva composta por procedimentos tipo estudos de casos. A pesquisa foi direcionada a usuários com diagnóstico de Paralisia Cerebral, nível motor IV e V (GMFCS) e que necessitam de um melhor posicionamento no sentar. Para as análises, foram utilizadas as almofadas pré-fabricadas que acompanham a cadeira em conjunto com as técnicas de mapeamento de pressão e termografia. As principais variáveis analisadas foram a distribuição de pressão e de temperatura, por meio de diagramas, bem como foram avaliados estatisticamente os respectivos valores médios. Os resultados demonstraram que nenhum dos 15 usuários avaliados apresentou postura adequada no sistema de assento e encosto padrão da cadeira de rodas. A distribuição da pressão mostrou-se inadequada, em geral, com picos importantes atribuídos à falta de estabilidade da pelve e do tronco. A utilização de cadeira de rodas com tilt é indicada, porém, faz-se necessária uma cuidadosa análise desse ângulo, bem como dos suportes de apoio ajustáveis às necessidades individuais. Recomenda-se a personalização das almofadas de assento, de encosto e de apoio de cabeça, através da moldagem do corpo do usuário. Destaca-se que os dados obtidos neste estudo podem auxiliar na identificação das necessidades dos usuários e, consequentemente, no projeto de assentos para cadeira de rodas, proporcionando maior qualidade de vida aos usuários. / The objective of this study is to evaluate the pressure distribution on the seat and backrest related to the angle variations of the wheelchair tilt-in-space. It also aims to contribute to a more suitable prescription of positioning systems. In order to do that, the descriptive research was structured by using case studies. The survey was targeted to users that had been diagnosed with cerebral palsy, gross motor function (GMFCS) IV and V who are need of a more appropriate wheelchair seating. Furthermore, for the analysis, the prefabricated chair cushions, the pressure mapping techniques and thermography had been used. The main variables analyzed were the distribution of pressure and temperature, through diagrams, which were statistically evaluated mean values. The results showed that none of the 15 members evaluated had an adequate posture in the standard seating system. The pressure distribution proved inadequate in general with important peaks attributed to the lack of stability of the pelvis and trunk. The use of the tilting wheelchair is recommended. However, it is required a more careful analysis of this angle, as well as the adjustable support brackets to individual needs. It is recommended to customize the seat cushions, backrest and headrest, through the user's body contour. It is noteworthy that the data obtained in this study can help identify the needs of users and consequently the seat design for a wheelchair, providing a higher quality of life to the users.

Orientadores: Rezende Gomes dos Santos, Ricardo Fuoco / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-08T07:46:15Z (GMT). No. of bitstreams: 1 Kolososki_Jorge_M.pdf: 7343986 bytes, checksum: 91fb9f7d500f8f650a42e7e445885c96 (MD5) Previous issue date: 2001 / Resumo: Durante o vazamento dos moldes, o fluxo de metal através dos canais está sujeito a grande turbulência, gerando filmes de óxidos devido a exposição ao ar. Estes óxidos podem permanecer nas peças fundidas como descontinuidades, prejudicando as propriedades, em particular a resistência mecânica e a dutilidade. São apresentados os principais conceitos e as principais recomendações existentes na literatura para o projeto dos sistemas de canais de ligas com elevada tendência à oxidação, como as ligas de alumínio. Estes princípios e recomendações foram utilizados para projetar seis diferentes sistemas de canais para o preenchimento de placas na posição vertical, utilizando liga de alumínio UNS A03560. A avaliação do grau de turbulência alcançado em cada um dos sistemas de canais projetados foi feita através da maior ou menor geração de inclusões de óxidos, medida através de ensaios de flexão de corpos-de-prova retirados diretamente das placas. São apresentados os resultados destes ensaios de flexão e evidências de inclusões de óxidos nas fraturas dos corpos-de-prova ensaiados / Abstract: During mould pouring, metal flow in runner system is submitted to large turbulence and air contact, producing oxide films. This oxide is incorporated to cast products as inclusions and discontinuities, reducing noticeably mechanical strength and ductility. The principal concepts and literature recommendations for the best runner system project applied to alloys with high oxidation tendency, like aluminum alloys, were presented in this work. This information was used to project six different runner systems for plate casting in vertical position, considering aluminum alloy UNS A03560 as the cast metal. The evaluation of turbulence degree reached in each one of the systems was made by oxide inclusion classification, comparing results of three-point bend tests in specimens obtained from the six plate cast procedures. Mechanical test results and oxide inclusion evidence in fracture surface of those broken specimens are presented. / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica