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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Integração do controle postural e de ações manuais em função da previsibilidade de perturbação e da demanda de precisão espacial / Integration between postural control and manual tasks as a function of predictability of perturbation and spatial precision demand

Lima, Elke dos Santos 01 April 2008 (has links)
O objetivo deste estudo foi analisar o controle postural diante da previsibilidade da carga elevada através de ação manual e da demanda atencional promovida pelo acréscimo de um alvo espacial na tarefa. Quinze sujeitos do sexo masculino (idade média 22,8+3,5 anos) realizaram a tarefa de elevação de uma caixa por meio da preensão manual, com massa variável (1, 3 e 5kg) nas condições previsível ou imprevisível. A tarefa também era executada em uma condição de maior demanda atencional promovida pela colocação de um alvo frontal, que deveria ser atingido por um facho de luz laser, cuja fonte estava fixada na caixa elevada pelo sujeito. Foram analisados o comportamento do centro de pressão (CP) e a cinemática das principais articulações e do movimento da caixa. Os resultados indicaram que a imprevisibilidade sobre a massa da caixa aumentou a oscilação do CP. Aumento da oscilação do CP também foi observado na situação de redução de massa, mesmo quando os sujeitos tinham conhecimento da mudança. A situação de pontaria em alvo induziu redução (a) do deslocamento do CP, (b) velocidade de elevação da caixa, e (c) amplitude de movimento do tornozelo e quadril. Estes resultados indicam que a previsibilidade sobre a ação de forças externas no corpo, demanda espacial da tarefa manual, e organização/feedback do movimento da tentativa anterior interagem para afetar o controle postural / The aim of this study was to analyze postural control as a function of predictability of a load lifted with the hands, and demand of spatial accuracy in the task. Fifteen males (mean age: 22.8 3.5 years) lifted boxes with variable masses (1, 3 and 5 kg), in conditions of predictable or unpredictable load. The task was performed either under lower spatial accuracy demand or aiming at a spatial target. Displacement of center of pressure (CP) and kinematics of the main joints/box motion were analyzed to access postural perturbation induced by the lifting task. Results showed that unpredictability about mass of the box enhanced CP displacement. Enhanced CP displacement was also observed in situations of decreased mass regarding the previous trial, even when participants were aware about the change. The pointing task induced decreased (a) CP displacement, (b) box lifting velocity, and (c) ankle and hip motion amplitude. These results indicate that predictability about external forces acting on the body, spatial demand of manual tasks, and movement organization/feedback of the previous trial interact to affect postural control
202

Innovation in construction techniques for tall buildings

Skelton, Ian R. January 2015 (has links)
The skyline of many 'world cities' are defined and punctuated by tall buildings. The drivers for such dominant skylines range from land scarcity and social needs; high real estate values; commercial opportunity and corporate demand, through to metropolitan signposting. This fascination with tall buildings started with the patrician families who created the 11th Century skyline of San Gimignano by building seventy tower-houses (some up to 50m tall) as symbols of their wealth and power. This was most famously followed in the late 19th Century with the Manhattan skyline, then Dubai building the world's highest building, then China building some eighty tall buildings completed in the last 5 years, then UK building Europe's highest tower, the Shard and finally back to Dubai, planning a kilometre tall tower, potentially realising Ludwig Mies van der Rohe's 'Impossible Dream' of the 1920's and Frank Lloyd Wright's 1956 'Mile High Illinois'. This ambition to build higher and higher continues to challenge the Architects, Engineers and Builders of tall buildings and is expected to continue into the future. The tall building format is clearly here to stay.
203

Strength Training and Body Composition in Middle-Age Women

Burrup, Rachelle 01 November 2015 (has links)
OBJECTIVE: The purpose of this study was to examine the relationship between strength training and body composition before and after controlling for several covariates. A cross-sectional study including 257 female subjects was conducted. METHODS: Subjects' level of involvement in strength training was determined via questionnaire. Body composition was assessed using dual energy X-ray absorptiometry (DXA). Diet was assessed using 7-d weighed food records. RESULTS: Strong linear relationships between subjects' level of involvement in strength training and body composition were identified. For each additional day of strength training reported per week, body fat was 1.32 percentage points lower (F = 14.8, p = 0.0002) and fat-free mass was 656.4 g (1.45 lb) higher (F = 18.9, p < 0.0001), on average. Likewise, the more time subjects spent lifting and the more intensely they trained, the better their body composition tended to be. Adjusting for differences in age, menopause status, objectively measured physical activity, energy intake, and protein intake tended to weaken each association. Controlling for differences in physical activity weakened each relationship the most. CONCLUSION: Women who strength train regularly tend to have significantly lower body fat percentages and significantly higher levels of fat-free mass compared to their counterparts, regardless of differences in several potential confounding variables.
204

Weighted interpolation over W*-algebras

Good, Jennifer Rose 01 July 2015 (has links)
An operator-theoretic formulation of the interpolation problem posed by Nevanlinna and Pick in the early twentieth century asks for conditions under which there exists a multiplier of a reproducing kernel Hilbert space that interpolates a specified set of data. Paul S. Muhly and Baruch Solel have shown that their theory for operator algebras built from W*-correspondences provides an appropriate context for generalizing this classic question. Their reproducing kernel W*-correspondences are spaces of functions that generalize the reproducing kernel Hilbert spaces. Their Nevanlinna-Pick interpolation theorem, which is proved using commutant lifting, implies that the algebra of multipliers of the reproducing kernel W*-correspondence associated with a certain W*-version of the classic Szegö kernel may be identified with their primary operator algebra of interest, the Hardy algebra. To provide a context for generalizing another familiar topic in operator theory, the study of the weighted Hardy spaces, Muhly and Solel have recently expanded their theory to include operator-valued weights. This creates a new family of reproducing kernel W*-correspondences that includes certain, though not all, classic weighted Hardy spaces. It is the purpose of this thesis to generalize several of Muhly and Solel's results to the weighted setting and investigate the function-theoretic properties of the resulting spaces. We give two principal results. The first is a weighted version of Muhly and Solel's commutant lifting theorem, which we obtain by making use of Parrott's lemma. The second main result, which in fact follows from the first, is a weighted Nevanlinna-Pick interpolation theorem. Other results, several of which follow from the two primary results, include the construction of an orthonormal basis for the nonzero tensor product of two W*-corrrespondences, a double commutant theorem, the identification of several function-theoretic properties of the elements in the reproducing kernel W*-correspondence associated with a weighted W*-Szegö kernel as well as the elements in its algebra of mutlipliers, and the presentation of a relationship between this algebra of multipliers and a weighted Hardy algebra. In addition, we consider a candidate for a W*-version of the complete Pick property and investigate the aforementioned weighted W*-Szegö kernel in its light.
205

Computational Fluid Dynamics Simulations of Oscillating Wings and Comparison to Lifting-Line Theory

Keddington, Megan 01 May 2015 (has links)
Computational fluid dynamics (CFD) analysis was performed in order to compare the solutions of oscillating wings with Prandtl’s lifting-line theory. Quasi-steady and steady-periodic simulations were completed using the CFD software Star-CCM+. The simulations were performed for a number of frequencies in a pure plunging setup. Additional simulations were then completed using a setup of combined pitching and plunging at multiple frequencies. Results from the CFD simulations were compared to the quasi-steady lifting-line solution in the form of the axial-force, normal-force, power, and thrust coefficients, as well as the efficiency obtained for each simulation. The mean values were evaluated for each simulation and compared to the quasi-steady lifting-line solution. It was found that as the frequency of oscillation increased, the quasi-steady lifting-line solution was decreasingly accurate in predicting solutions.
206

A biomechanical analysis of patient handling techniques and equipment in a remote setting.

Muriti, Andrew John, Safety Science, Faculty of Science, UNSW January 2005 (has links)
Remote area staff performing manual patient handling tasks in the absence of patient lifting hoists available in most health care settings are at an elevated risk of musculoskeletal injuries. The objective of this project was to identify the patient handling methods that have the lowest risk of injury. The patient handling task of lifting a patient from floor to a chair or wheelchair is a common task performed in a remote health care setting. The task was performed utilising three methods, these being: (1) heads/tails lift, (2) use of two Blue MEDesign?? slings and (3) use of a drawsheet. The task of the heads/tails lift was broken down into two distinctly separate subtasks: lifting from the (1) head and (2) tail ends of the patient load. These techniques were selected based on criteria including current practice, durability, portability, accessibility, ease of storage and cost to supply. Postural data were obtained using a Vicon 370 three - dimensional motion measurement and analysis system in the Biomechanics & Gait laboratory at the University of New South Wales. Forty reflective markers were placed on the subject to obtain the following joint angles: ankle, knee, hip, torso, shoulder, elbow, and wrist. The raw data were converted into the respective joint angles (Y, X, Z) for further analysis. The postural data was analysed using the University of Michigan???s Three-Dimensional Static Strength Prediction Program (3D SSPP) and the relative risk of injury was based on the following three values: (1) a threshold value of 3,400 N for compression force, (2) a threshold value of 500 N for shear force, and (3) population strength capability data. The effects on changes to the anthropometric data was estimated and analysed using the in-built anthropometric data contained within the 3D SSPP program for 6 separate lifter scenarios, these being male and female 5th, 50th and 95th percentiles. Changes to the patient load were estimated and analysed using the same computer software. Estimated compressive and shear forces were found to be lower with the drawsheet and tail component of the heads/tails lift in comparison to the use of the Blue MEDesign?? straps and head component of the heads/tails lift. The results obtained for the strength capability aspect of each of the lifts indicated a higher percentage of the population capable of both the drawsheet and tail end of the heads/tails lift. The relative risk of back injury for the lifters is distributed more evenly with the drawsheet lift as opposed to the heads/tails (tail) lift where risk is disproportionate with the heavier end being lifted. The use of lifter anthropometrics does not appear to be a realistic variable to base assumptions on which group of the population are capable of safely performing this task in a remote setting. This study advocates the use of the drawsheet lift in a remote setting based on the author???s experience and the biomechanical results obtained in this study. The drawsheet lift is both more accessible and provides a more acceptable risk when more than two patient handlers are involved, in comparison to the other lifts utilised lifting patients from floor to a chair.
207

Lifting the Corporate Veil : Do we need to regulate this institute in swedish law? / Ansvarsgenombrott för aktieägare : Med särskilt avseende på de faktorer och principer som kan föranleda ett genombrott och om institutet behöver lagregleras i svensk rätt

Konradsson, Charlotta January 2000 (has links)
<p>The subject for this composition is the instute"ansvarsgenombrott"which in english is called"lifting the corporate veil"or"piercing the corporate veil". This institute has given rise to several very controversial questions. The most important questions are: Which principles must be fulfilled if the institute shall come in to question and is there a need for a regulation of the institute in swedish law?</p>
208

Lifting the Corporate Veil : Do we need to regulate this institute in swedish law? / Ansvarsgenombrott för aktieägare : Med särskilt avseende på de faktorer och principer som kan föranleda ett genombrott och om institutet behöver lagregleras i svensk rätt

Konradsson, Charlotta January 2000 (has links)
The subject for this composition is the instute"ansvarsgenombrott"which in english is called"lifting the corporate veil"or"piercing the corporate veil". This institute has given rise to several very controversial questions. The most important questions are: Which principles must be fulfilled if the institute shall come in to question and is there a need for a regulation of the institute in swedish law?
209

Aerostructural Optimization of Non-planar Lifting Surfaces

Jansen, Peter Willi 14 July 2009 (has links)
Non-planar lifting surfaces offer potentially significant gains in aerodynamic efficiency by lowering induced drag. Non-aerodynamic considerations, such as structures can impact the overall efficiency. Here, a panel method and equivalent beam finite element model are used to explore non-planar configurations taking into account the coupling between aerodynamics and structures. A single discipline aerodynamic optimization and a multidisciplinary aerostructural optimization are investigated. Due to the complexity of the design space and the presence of multiple local minima, an augmented Lagrangian particle swarm optimizer is used. The aerodynamic optimum solution found for rectangular lifting surfaces is a box wing, while allowing for sweep and taper yields a joined wing. Adding parasitic drag in the aerodynamic model reduces the size of the non--planar elements. The aerostructural optimal solution found is a winglet configuration when the span is constrained and a wing rake when there is no such constraint.
210

Differential effects of strength training and endurance training on parameters related to resistance to gravitational forces

Kim, Hyung Don 07 February 1991 (has links)
Graduation date: 1991

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