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The floating cup principle is a general hydrostatic principle for both constant and variable displacement pumps and motors, as well as for hydraulic transformers. In this paper, the focus will be entirely on the control of the displacement of the variable 28 cc Floating Cup pump (FCVP28). The floating cup principle features two opposed swash plates, for which both angular positions need to be controlled in order to cover the entire range from zero to full displacement. The results of both extended numerical analysis as well as simplified linearized models will be compared to test results on a 28 cc FCVP. Special emphasis will be on the dynamic behaviour of the displacement control.

Fokus i examensarbetet har varit att konstruera och programmera en självstyrande bil med avgränsningar till regelverket i tävlingen Freescale cup. Då studien befinner sig i en tävlingsdomän, blir precision och hastighet två huvudfaktorer för linjeföljning och navigering. För att bemöta de ovanstående problem, fokuseras studien i denna rapport på utvecklandet av en ljusbehandlar-algoritm. Detta för hantera och standardisera linjeavkodningen och linjeidentifieringen. Detta kombinerat med en primärreglering som hanterar styrningen med avseende på linjeidentifieringen med tidsförskjutning för sekundärreglering vid behov. För att mäta precision utfördes tester genom tre olika metoder på linjeavläsningen: (1) avläsning av sensordata utan filtrering,(2) avläsning av sensordata via Kalmanfilter samt (3) avläsning av sensordata med en adaptiv ljusalgoritm för de olika fälten och ljusförhållanden. Dessa i kombination med väl injusterad PID-styralgoritm borgade för god precision och linjeföljning under dåliga förhållanden.   Studien påvisar att med den adaptiva ljusalgoritmen i kombination med linjeföljaralgoritmen och sekundärreglering via look ahead-algoritmen kan hastigheter som tangerar optimala förhållanden även uppnås under mer kaotiska och dåliga förhållanden. Bilen finner sin väg trots ljusförhållanden så låga som 20 lux. Studien styrker även fördelarna med den adaptiva ljusalgoritmen i kombination med linjeföljaralgoritmen och look ahead-algoritmen som primärreglering under optimala driftförhållanden.   Effektiviteten av studien och de algoritmer de mynnades ut i kvantifierades och jämfördes genom varvtider och dess linjeföljarförmåga under olika ljusförhållanden och olika gynnsamma underlag. Som ytterligare ett led för att få upp snitthastigheten med aktiv chassidynamik, nyttjades styrvinkeln som en funktion till differentialdriften av motorerna för att bibehålla sitt väggrepp genom kurvorna och hastigheten med aktiv hastighetskontroll.

Periacetabular osteolysis is a significant complication following total hip replacement surgery. It is believed to be caused by wear debris and high fluid pressures within the joint capsule. To investigate the mechanisms by which high fluid pressures are generated in total hip replacement, a physical model of the hip joint was constructed, the Acetabular Pressure Transmission Rig (APTR). An aluminium chamber held the bone analogue, a polyurethane hemisphere with a 52mm acetabular cavity, and the prosthetic components, a 28mm femoral head and various uncemented cups, were inserted without press-fit to simulate cup loosening. A synovial fluid analogue was introduced into the chamber through an elevated reservoir. Rigid transmission tubes conducted fluid pressures from the cup-cavity interface to external transducers. The APTR was loaded under various conditions and the pressures produced by the loading regimes were analysed. Pressures over 35kPa, previously shown by other groups to cause osteolysis, were measured within the APTR, reaching a maximum of 131.3kPa measured at the pole of the cup. Changes in load application led to pressure changes within the APTR, with higher loading frequency and magnitude leading to higher median pressure amplitudes. The presence of different component features, such as screw holes in the metal shell, was also shown to affect periacetabular pressures. Tests with a fibrous rim interposed between the prosthetic cup and the test cavity showed an 88% reduction in periacetabular pressures, as the increased rim interference between cup and cavity prevented fluid ingress behind the cup. A larger initial separation between the loading head and the acetabular cup caused a significant increase in measured pressures, with a 0.15mm increase in head-cup separation producing a 53% increase in pressures measured at the pole of the cup. Pressure differentials between different transducer sites indicated the ability for fluid flow behind the cup, which can be related in vivo to the movement of particulate debris to periacetabular bone. The APTR was able to measure clinically significant pressures and to analyse the effects of modifying component and loading characteristics with currently available prosthetic components. This makes the rig useful in a clinical context, as it has been shown to be capable of testing a broad range of component types under a wide range of conditions. Its use will ensure new prostheses and fixation modes can be designed in such a way as to eliminate the damaging fluid pressures currently observed in artificial hip joint replacements.

Grinding set-up in America's Cup sailing provides the power behind tacking and gybing, where the yacht crosses the wind to change direction. Grinding is also used for trimming the sails, which changes the angle on which the yacht is headed. This study provided a descriptive biomechanical overview of grinding on an America's Cup class yacht, and experimentally evaluated the influence of technique instruction on backward grinding performance. Inter-subject differences in body position (technique) throughout the grinding cycle, the ability to alter grinding technique within an eight-day technique intervention period, and the effect of technique on grinding performance as determined by power output were assessed. The quasi-experimental design, in which each of eleven Team New Zealand America's Cup grinders served as their own control, assessed four trials of backward grinding at baseline and post-biomechanical technique intervention testing sessions. Each trial was a maximal effort performed against a high load (250 W) and sustained over a period of eight seconds. Sagittal plane video was used to analyse joint kinematics (elbow, shoulder, trunk, hip, knee, ankle angles and joint centre positions) and to calculate the centre of body mass relative to the grinder pedestal. Height, weight, and limb lengths were obtained from each grinder using the ISAK protocol. Current backward grinding technique employed by the majority of grinders did not optimally use biomechanical principles. Recommendations for improvement were specific to each individual but focused on lowering trunk position and distancing the trunk from the grinding pedestal. Real-time visual feedback was provided to the grinder operators with the main focus being the position of their hip joint (viewed in the sagittal plane), and lowering the shoulder to be vertically level with the apex of the grinding handle cycle. During the intervention the grinders were given added correctional instruction relating to their body position according to perceived technique requirements. Recommendations were based on biomechanical principles regarding body position, and how body position could be altered to optimise the contribution of body weight and force production by the muscles of the upper limb in order to improve the torque applied to the handles. Altering grinding technique according to biomechanical principles produced 4.7% (p = 0.012) greater power during five seconds of grinding performance. Muscular strength, when measured using a 1RM bench pull (116.4 ± 9.8 to 117.3 ± 10.3), was unaffected by the intervention program, thus not contributing to the increased power output observed during grinding. Moderate changes to body position were observed after the eight-day intervention. Forward lean of the trunk decreased from 25° to 17° (p = 0.028) due to a lower hipy position (-0.09 m to -0.16 m below hub, p = 0.019). The more vertical trunk alignment resulted in the shoulderx position being further from the hub (0.33 m to 0.41 m, p = 0.013), producing a greater line of pull due to a more efficient shoulder vector angle (47° to 36°, p = 0.009). Variability (standard deviation and confidence intervals) decreased in all but four kinematic measures (which exhibited no change) indicating improved consistency in grinding technique. Regression analysis indicated the best predictors for high-load backward grinding performance were COMx position relative to the grinding pedestal and maximal strength. Changes in COMx position explained 40% (p = 0.166) of the variation in grinding performance, while maximal strength showed a relationship of 0.23% (p = 0.144) increase in performance per kilogram of bench pull 1RM. A one standard deviation difference in maximal strength altered the effect of COMx position by 0.26% per centimetre (p = 0.008). Weaker predictive factors were body weight, standing height, and pull angle, while brachial index did not appear to have any substantial influence on backward grinding performance. For future research greater subject numbers should enable more conclusive findings, especially in terms of the technique mechanisms and their relative levels of influence on performance.

On May 2011, the Environmental Protection Administration launched a policy to cut the use of disposable cups. This policy obliges non-alcoholic beverage stores to give customers incentives for bringing their own cups or recycling disposable cups. Because college students often buy take-out non-alcoholic beverage, this study aimed to explore how psychological variables might affect their intent to bringing their own cups. Results from this study may provide some suggestions for the policy above. This study started with a focus group interview with 31 college students. This interview gave me a preliminary understanding of students¡¦ intent to bring their own cups and the related psychological factors. I then combined the findings from this interview and literature review to design the framework and questionnaire for this study. Following Kotler and Lee¡¦s (2008) concept of social marketing, the questionnaire was mainly designed to assess five variables: policy incentive, benefit of bringing own cups, cost of bringing own cups, convenience in buying cups, and convenience in washing cups. A convenience sample of 197 students in National Sun Yat-sen University participated. The results suggest the higher the profit or the lower the cost for bringing own cups, the stronger will be students¡¦ intent to do so. However, the other three variables had no significant effect. In addition, the analysis showed female students were more intended to bring their own cups than male students did. Students from different departments also differed in their intent, but the differences were small. Based on these findings, several policy recommendations were proposed.

Thesis (M.A. (Human Movement Sciences))--University of Pretoria, 2009. / Abstract in English and Afrikaans. Includes bibliographical references.

In 2010, South Africa became the first country on the continent of Africa to host a World Cup. This thesis analyzes aspects of the planning process for this mega-event. My analysis focuses on three interrelated phenomena: public order policing and re-branding through the control of public space; policy transfer and the attempt to clone the 'world-class' city in South Africa; and, the influence of consciously planning for an external television audience on the uneven geographies and temporalities of the mega-event. First, in analyzing the processes of public order policing and its connection to city branding in Durban, South Africa during the World Cup, I trace three mechanisms: the regulation of nuisance behaviors, the restriction of social movement activities, and the introduction of welcome ambassadors. I argue that this policing strategy reveals what city planners believe to be appropriate uses of public space as well as a future vision of the city. Second, using “cultural cloning” as a metaphor, I argue that policy mobility and the valorization of “best practices” can reinforce hegemonic conceptions of a 'world class' city that exacerbate already existing social inequalities. Such notions, also, work to foreclose on alternative visions of how a 'world class' World Cup host city might act such as those articulated in the World Class Cities for All campaign. Third, I examine how the particular medium of television works to shape urban planning, the production of space and the processes of urban knowledge production during mega-events. Such a theoretical approach necessitates closer examination of the relationship between urban planning and urban knowledge production through television. In the conclusion of my dissertation, I put my work in context of recent events and struggles that have emerged in Brazil as that country gets set to host the 2014 World Cup and the 2016 Summer Olympics. Additionally, I highlight what I believe to be the key scholarly contributions of this project and outline a future research agenda that emerges from this work.

In 2010, South Africa became the first country on the continent of Africa to host a World Cup. This thesis analyzes aspects of the planning process for this mega-event. My analysis focuses on three interrelated phenomena: public order policing and re-branding through the control of public space; policy transfer and the attempt to clone the 'world-class' city in South Africa; and, the influence of consciously planning for an external television audience on the uneven geographies and temporalities of the mega-event. First, in analyzing the processes of public order policing and its connection to city branding in Durban, South Africa during the World Cup, I trace three mechanisms: the regulation of nuisance behaviors, the restriction of social movement activities, and the introduction of welcome ambassadors. I argue that this policing strategy reveals what city planners believe to be appropriate uses of public space as well as a future vision of the city. Second, using “cultural cloning” as a metaphor, I argue that policy mobility and the valorization of “best practices” can reinforce hegemonic conceptions of a 'world class' city that exacerbate already existing social inequalities. Such notions, also, work to foreclose on alternative visions of how a 'world class' World Cup host city might act such as those articulated in the World Class Cities for All campaign. Third, I examine how the particular medium of television works to shape urban planning, the production of space and the processes of urban knowledge production during mega-events. Such a theoretical approach necessitates closer examination of the relationship between urban planning and urban knowledge production through television. In the conclusion of my dissertation, I put my work in context of recent events and struggles that have emerged in Brazil as that country gets set to host the 2014 World Cup and the 2016 Summer Olympics. Additionally, I highlight what I believe to be the key scholarly contributions of this project and outline a future research agenda that emerges from this work.

Grinding set-up in America's Cup sailing provides the power behind tacking and gybing, where the yacht crosses the wind to change direction. Grinding is also used for trimming the sails, which changes the angle on which the yacht is headed. This study provided a descriptive biomechanical overview of grinding on an America's Cup class yacht, and experimentally evaluated the influence of technique instruction on backward grinding performance. Inter-subject differences in body position (technique) throughout the grinding cycle, the ability to alter grinding technique within an eight-day technique intervention period, and the effect of technique on grinding performance as determined by power output were assessed. The quasi-experimental design, in which each of eleven Team New Zealand America's Cup grinders served as their own control, assessed four trials of backward grinding at baseline and post-biomechanical technique intervention testing sessions. Each trial was a maximal effort performed against a high load (250 W) and sustained over a period of eight seconds. Sagittal plane video was used to analyse joint kinematics (elbow, shoulder, trunk, hip, knee, ankle angles and joint centre positions) and to calculate the centre of body mass relative to the grinder pedestal. Height, weight, and limb lengths were obtained from each grinder using the ISAK protocol. Current backward grinding technique employed by the majority of grinders did not optimally use biomechanical principles. Recommendations for improvement were specific to each individual but focused on lowering trunk position and distancing the trunk from the grinding pedestal. Real-time visual feedback was provided to the grinder operators with the main focus being the position of their hip joint (viewed in the sagittal plane), and lowering the shoulder to be vertically level with the apex of the grinding handle cycle. During the intervention the grinders were given added correctional instruction relating to their body position according to perceived technique requirements. Recommendations were based on biomechanical principles regarding body position, and how body position could be altered to optimise the contribution of body weight and force production by the muscles of the upper limb in order to improve the torque applied to the handles. Altering grinding technique according to biomechanical principles produced 4.7% (p = 0.012) greater power during five seconds of grinding performance. Muscular strength, when measured using a 1RM bench pull (116.4 ± 9.8 to 117.3 ± 10.3), was unaffected by the intervention program, thus not contributing to the increased power output observed during grinding. Moderate changes to body position were observed after the eight-day intervention. Forward lean of the trunk decreased from 25° to 17° (p = 0.028) due to a lower hipy position (-0.09 m to -0.16 m below hub, p = 0.019). The more vertical trunk alignment resulted in the shoulderx position being further from the hub (0.33 m to 0.41 m, p = 0.013), producing a greater line of pull due to a more efficient shoulder vector angle (47° to 36°, p = 0.009). Variability (standard deviation and confidence intervals) decreased in all but four kinematic measures (which exhibited no change) indicating improved consistency in grinding technique. Regression analysis indicated the best predictors for high-load backward grinding performance were COMx position relative to the grinding pedestal and maximal strength. Changes in COMx position explained 40% (p = 0.166) of the variation in grinding performance, while maximal strength showed a relationship of 0.23% (p = 0.144) increase in performance per kilogram of bench pull 1RM. A one standard deviation difference in maximal strength altered the effect of COMx position by 0.26% per centimetre (p = 0.008). Weaker predictive factors were body weight, standing height, and pull angle, while brachial index did not appear to have any substantial influence on backward grinding performance. For future research greater subject numbers should enable more conclusive findings, especially in terms of the technique mechanisms and their relative levels of influence on performance.