Thesis (M.Med.Sc.)--University of Hong Kong, 2004. / Also available in print.

Thesis (M.S.)--Oregon State University, 2004. / Printout. Includes bibliographical references (leaves 61-62). Also available on the World Wide Web.

Made available in DSpace on 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-01Bitstream added on 2014-06-13T19:37:20Z : No. of bitstreams: 1 akiyama_mk_me_guara.pdf: 2877437 bytes, checksum: f64beca66421f23a46b9c0d6fe1c82e0 (MD5) / Universidade Estadual Paulista (UNESP) / Neste trabalho é feito um estudo de comportamento dinâmico de um veículo pequeno com suspensão passiva trafegando em pista com ondulações regulares, e análise da estabilidade. O veículo é modelado considerando-o como um sistema multicorpo rígido, com sete graus de liberdade, utilizando-se o método de Kane. As equações do movimento são definidas sobre uma listagem de programa preparada segundo o programa AUTOLEV, o qual emite um programa em linguagem FORTRAN para as simulações. Foi necessário obter-se diretamente do veículo dados característicos como: centros de gravidade, coeficientes de rigidez dos pneus e das molas, e coeficientes de amortecimento para a realização das simulações. Além disso, foram definidos dois tipos de rugosidade, quatro velocidades, duas seqüências de rugosidade, sendo uma com cinco ondas e outra com vinte ondas, bem como a consideração do veículo com um ocupante e cinco ocupantes. Com os resultados do processamento dos dados, foram traçados gráficos e realizadas análises dos efeitos das rugosidades sobre a dinâmica do veículo, conclusões e apresentações de sugestões. / In this paper we study the dynamic behaviour of a small vehicle provided with passive suspension, riding on regularly rugged roads, and stability analysis. The vehicle is modelled considering as a rigid multibody system, with seven degrees of freedom, applying the Kaneþs method. Motion equations are defined on a program list according to the AUTOLEV software, which gives a FORTRAN language program for simulations. It was necessary to obtain directly from the vehicle, characteristic datas as centres of gravity, tires and springs stiffnesses, damper characteristics. In addition, it was defined two road roughnesses, four riding speeds, two sequences of roughness, one with five and other with twenty waves, as well as the consideration of vehicle with one and five occupants. With the results of processing, graphics were plotted, and analysis realized about roughness effects on vehicle dynamics and presentations of suggestions.

The theory and design of lumped element quadrature hybrids is presented. The principal area of interest is in passive circuits, exhibiting exact quadrature performance, for use in radio frequency circuits. The state of the art prior to the present research is reviewed, considering the available theory in the literature, and also the general specifications of commercially available products. The fundamental limitations of exact quadrature hybrids are considered, and governing equations are derived for realisable circuits. The theory of approximation as it applies to quadrature hybrids is considered, and useful classes of function are solved. Particular attention is paid to a rational Chebychev class of function, which offers the prospect of exceptionally wide bandwidth. The approximation functions in the real frequency domain are then transformed into the equivalent functions using the complex frequency variable, so as to be suitable for synthesis. Passive circuits, which implement the approximation functions already considered, are synthesized. Both low-pass and band-pass circuits are found to exhibit suitable properties. Practical realisations of the synthesized circuits are described, together with their measured performance. Good agreement is seen between theory and practice. Other aspects of quadrature hybrid design are considered, including a comparison with approximate phase hybrids, active circuits, power handling, weak couplers, graphical techniques and a figure of merit method of assessing the performance of quadrature hybrids. The direction for future research is considered and an assessment of the achievements of the research is made.

ABSTRACT : THESIS PART ONE. The thermal performances of two schools with central atria, and a typical primary school class- base, were assessed using the SERI-RES computer model. ABSTRACT : THESIS PART TWO. To improve the modelling of sunlight and daylight, measured values of solar radiation, recorded at one minute intervals, were used to examine the relationship attributed to Lui A Jordan(1960), between the fraction of the solar radiation which is received on a horizontal surface, and the equivalent diffuse fraction,

Aging is accompanied by a deterioration of physical abilities. For some this limits their mobility and thus their quality of life. Exoskeletons are a class of walking assist device that help reduce the effort required to walk. Currently, powered exoskeletons suffer from short battery life and thus limited usefulness. This thesis presents the design, fabrication, and testing of a novel unpowered ankle exoskeleton to assist normal walking over long distances. The design incorporates a Pneumatic Artificial Muscle (PAM) inflated and used as a passive air spring. To predict the behaviour of the PAM in this distinct application, a distinct dynamic model was developed to include the biaxial stress in the bladder as well as a polytropic gas assumption. Experimental testing was used to validate the model and indicated that the addition of the bladder stress enhanced the performance of the force prediction at low pressure but had negligible impact on the model at higher pressures. The experimental testing also showed that the temperature of the gas inside the PAM varies very slightly during passive elongation cycles, thus, validating an isothermal assumption. Once fabricated, the exoskeleton was tested in human walking trials. Electromyography results showed that the exoskeleton was able to reduced the muscular activation activation of the Soleus muscle, however the results also included a significant reduction in the angular range of motion of the ankle. This is thought to be attributed to an insufficient acclimatization period during the human testing. Furthermore, due to an improper fit of the exoskeleton, the clutch mechanism did not operate as designed, leading to a reduced range of motion of the ankle. The device demonstrated its ability to reduce the effort of the calf muscles during walking, however, further refinements of the device fitting and clutch mechanism are required.

The English voice system has two passive auxiliaries: the canonical be-passive, and the more recent get-passive. Accounts of the get-passive in the linguistic literature draw from descriptive, historical, corpus linguistic, and variationist perspectives. Much existing work on the get-passive from the former three traditions notes semantic dissimilarities from the be-passive, suggesting that these two forms are not interchangeable and therefore do not constitute a typical sociolinguistic variable. Nonetheless, variationist work has treated the be- and get-passives as alternants expressing the same function. This latter work has focused on social factors alone, setting aside purported linguistic differences. This thesis provides a variationist account of the be- and get-passives, considering not only social factors, but also operationalizing as linguistic factors previously noted semantic characteristics, demonstrating which factors constrain variation and providing a holistic picture of the get-passive in vernacular English. The speakers in this study span a birth range of 1865 to 1996, providing a longitudinal scope from which to view the grammaticalization of the feature. Following the principle of accountability (Labov, 1972), instances of be- and get-passives were extracted from 108 speakers born and raised in Victoria, British Columbia, Canada (N=1716). Distributional and inferential results show a substantial increase in rates of get-passive over the last 130 years, indicating an active and ongoing change in progress. Social and linguistic factors alike are shown to play meaningful roles in variant selection, revealing a (largely) longitudinally stable variable grammar. The longitudinal scope of the study illuminates grammaticalization pathways into the 20th century and reinforces attested semantic links between the contemporary get-passive and its proposed lexical source(s). / Graduate / 2023-08-17

The experimental program presented in this paper explores a passive acoustic baseball bat swing speed measurement technique to aid in product development and certification and to gauge player performance. The collection of experimental information is performed in two facilities?a swing/hit facility and a wind tunnel facility. The data acquired are pressures and velocities in the vicinity of the bat. Potential flow theory is utilized to better understand the signals generated in the experimental collection of data and to determine the fundamental relations applicable to the subsequent flow field produced by a moving bat. The measured flow resembles potential flow but with a distortion due to bat acceleration. The theoretical and experimental results are compared, and a qualitative similarity in the results is established.

No description available.

A flexible and passive exoskeleton is presented in this paper. The exoskeleton uses carbon fiber beams to provide an energetic return to its wearer and relieve their lower back muscles. The design of the exoskeleton and potential elastic mechanisms are described, and the results of biomechanical testing are given. The exoskeleton decreased the erector spinae muscle activity by 21-39.7%. / MS