280 resultados para forces de cisaillement


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This PhD study examines whether water allocation becomes more productive when it is re-allocated from 'low' to 'high' efficient alternative uses in village irrigation systems (VISs) in Sri Lanka. Reservoir-based agriculture is a collective farming economic activity, which inter-sectoral allocation of water is assumed to be inefficient due to market imperfections and weak user rights. Furthermore, the available literature shows that a „head-tail syndrome. is the most common issue for intra-sectoral water management in „irrigation. agriculture. This research analyses the issue of water allocation by using primary data collected from two surveys of 460 rice farmers and 325 fish farming groups in two administrative districts in Sri Lanka. Technical efficiency estimates are undertaken for both rice farming and culture-based fisheries (CBF) production. The equi-marginal principle is applied for inter and intra-sectoral allocation of water. Welfare benefits of water re-allocation are measured through consumer surplus estimation. Based on these analyses, the overall findings of the thesis can be summarised as follows. The estimated mean technical efficiency (MTE) for rice farming is 73%. For CBF production, the estimated MTE is 33%. The technical efficiency distribution is skewed to the left for rice farming, while it skewed to the right for CBF production. The results show that technical efficiency of rice farming can be improved by formalising transferability of land ownership and, therefore, water user rights by enhancing the institutional capacity of Farmer Organisations (FOs). Other effective tools for improving technical efficiency of CBF production are strengthening group stability of CBF farmers, improving the accessibility of official consultation, and attracting independent investments. Inter-sectoral optimal allocation shows that the estimated inefficient volume of water in rice farming, which can be re-allocated for CBF production, is 32%. With the application of successive policy instruments (e.g., a community transferable quota system and promoting CBF activities), there is potential for a threefold increase in marginal value product (MVP) of total reservoir water in VISs. The existing intra-sectoral inefficient volume of water use in tail-end fields and head-end fields can potentially be removed by reducing water use by 10% and 23% respectively and re-allocating this to middle fields. This re-allocation may enable a twofold increase in MVP of water used in rice farming without reducing the existing rice output, but will require developing irrigation practices to facilitate this re-allocation. Finally, the total productivity of reservoir water can be increased by responsible village level institutions and primary level stakeholders (i.e., co-management) sharing responsibility of water management, while allowing market forces to guide the efficient re-allocation decisions. This PhD has demonstrated that instead of farmers allocating water between uses haphazardly, they can now base their decisions on efficient water use with a view to increasing water productivity. Such an approach, no doubt will enhance farmer incomes and community welfare.

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Three-dimensional wagon train models have been developed for the crashworthiness analysis using multi-body dynamics approach. The contributions of the train size (number of wagon) to the frontal crash forces can be identified through the simulations. The effects of crash energy management (CEM) design and crash speed on train crashworthiness are examined. The CEM design can significantly improve the train crashworthiness and the consequential vehicle stability performance - reducing derailment risks.

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Information Technology (IT) is an important resource that can facilitate growth and development in both the developed and developing economies. The forces of globalisation increase the digital divide between the developed and developing economies is increasing. The least developed economies (LDEs) are the most vulnerable within this environment. Intense competition for IT resources means that LDEs need a deeper understanding of how to source and evaluate their IT-related efforts. This effort puts LDEs in a better position to source funding from various stakeholders and promote localized investment in IT. This study presents a complementary approach to securing better IT-related business value in organizations in the LDEs. It further evaluates how IT and the complementaries need to managed within the LDEs. Analysis of data collected from five LDEs show that organizations that invest in IT and related complementaries are able to better their business processes. The data also suggest that improved business processes lead to overall business processes improvements. The above is only possible if organizations adopt IT and make related changes in the complementary resources within the established culture and localizing the required changes.

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Nursing personnel are consistently identified as one of the occupational groups most at risk of work-related musculoskeletal disorders. During the moving and handling of bariatric patients, the weight of the patient combined with atypical body mass contributes to a significant risk of injury to the care provider and patient. This is further compounded by the shape, mobility and co-operation of the patient. The aim of this study was determine user experiences and design requirements for mobile hoists with bariatric patients. Structured interviews were conducted with six experienced injury management staff from the Manual Task Services department of three hospitals in Adelaide, South Australia. All staff had experience in patient handling, the use of patient handling equipment and the provision of patient handling training. A series of open-ended questions were structured around five main themes: 1) patient factors; 2) building/vehicle space and design; 3) equipment and furniture; 4) communication; and 5) staff issues. Questions focussed on the use of mobile hoists for lifting and transferring bariatric patients. Interviews were supplemented with a walk-through of the hospital to view the types of mobile hoists used, and the location and storage of equipment. Across the three hospitals there were differing classification systems to define bariatric patients. Ensuring patient dignity, respect and privacy were viewed as important in the management and rehabilitation of bariatric patients. Storage and space constraints were considered factors restricting the use of mobile floor hoists, with ceiling hoists being the preferred method for patient transfers. When using mobile floor hoists, the forces required to push, pull and manoeuvre, as well as sudden unstable movements of the hoist were considered important risks factors giving rise to a risk of injury to the care provider. Record keeping and purchasing policies appeared to inhibit the effective use of patient handling equipment. The moving and handling of bariatric patients presents complex and challenging issues. A co-ordinated and collaborative approach for moving and handling bariatric patients is needed across the range of care providers. Designers must consider both user and patient requirements.

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When compared with similar joint arthroplasties, the prognosis of Total Ankle Replacement (TAR) is not satisfactory although it shows promising results post surgery. To date, most models do not provide the full anatomical functionality and biomechanical range of motion of the healthy ankle joint. This has sparked additional research and evaluation of clinical outcomes in order to enhance ankle prosthesis design. However, the limited biomechanical data that exist in literature are based upon two-dimensional, discrete and outdated techniques1 and may be inaccurate. Since accurate force estimations are crucial to prosthesis design, a paper based on a new biomechanical modeling approach, providing three dimensional forces acting on the ankle joint and the surrounding tissues was published recently, but the identified forces were suspected of being under-estimated, while muscles were . The present paper reports an attempt to improve the accuracy of the analysis by means of novel methods for kinematic processing of gait data, provided in release 4.1 of the AnyBody Modeling System (AnyBody Technology, Aalborg, Denmark) Results from the new method are shown and remaining issues are discussed.

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In this work a biomechanical model is used for simulation of muscle forces necessary to maintain the posture in a car seat under different support conditions.

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In order to gain a competitive edge in the market, automotive manufacturers and automotive seat suppliers have identified seat ergonomics for further development to improve overall vehicle comfort. Adjustable lumbar support devices have been offered since long as comfort systems in either a 2-way or 4-way adjustable configuration, although their effect on lumbar strain is not well documented. The effect of a lumbar support on posture and muscular strain, and therefore the relationship between discomfort and comfort device parameter settings, requires clarification. The aim of this paper is to study the effect of a 4-way lumbar support on lower trunk and pelvis muscle activity, pelvic tilt and spine curvature during a car seating activity. 10 healthy subjects (5 m/f; age 19-39) performed a seating activity in a passenger vehicle with seven different static lumbar support positions. The lumbar support was tested in 3 different height positions in relation to the seatback surface centreline (high, centre, low), each having 2 depths positions (lumbar prominence). An extra depth position was added for the centre position. Posture data were collected using a VICON MX motion capture system and NORAXON DTS goniometers and inclinometer. A rigid-body model of an adjustable car seat with four-way adjustable lumbar support was constructed in UGS Siemens NX and connected to a musculoskeletal model of a seated-human, modelled in AnyBody. Wireless electromyography (EMG) was used to calibrate the musculoskeletal model and assess the relationship between (a) muscular strain and lumbar prominence (normal to seatback surface) respective to the lumbar height (alongside seatback surface), (b) hip joint moment and lumbar prominence (normal to seatback surface) respective to lumbar height (alongside seatback surface) and (c) pelvic tilt and lumbar prominence (normal to seatback surface) respective to the lumbar height (alongside seatback surface). This study was based on the assumption that the musculoskeletal human model was seated at the correct R-Point (SgRP), determined via the occupant packaging toolkit in the JACK digital human model. The effect of the interaction between the driver/car-seat has been investigated for factors resulting from the presence and adjustment of a 4-way lumbar support. The results obtained show that various seat adjustments, and driver’s lumbar supports can have complex influence on the muscle activation, joint forces and moments, all of which can affect the comfort perception of the driver. This study enables the automotive industry to optimise passenger vehicle seat development and design. It further more supports the evaluation of static postural and dynamic seat comfort in normal everyday driving tasks and can be applied for future car design to reduce investment and improve comfort.

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At first glance the built environments of South Florida and South East Queensland appear very similar, particularly along the highly urbanized coast. However this apparent similarity belies some fundamental differences between the two regions in terms of context and the approach to regulating development. This paper describes some of these key differences, but focuses on two research questions: 1) do these differences affect the built environment; and 2) if so, how does the built form differ? There has been considerable research on how to best measure urban form, particularly as it relates to measuring urban sprawl (Schwarz 2010; Clifton et al. 2008). Some of the key questions identified by this research include: what are the best variables to use?; what scale should be used?; and what time period to use? We will assimilate this research in order to develop a methodology for measuring urban form and apply it to both case study regions. There are several potential outcomes from this research -- one is that the built form between the two regions is quite different; and the second is that it is similar. The first outcome is what might be expected given the differences in context and development regulation. However how might the second outcome be explained – major differences in context and development regulation resulting in minor differences in key measures of urban form? One explanation is that differences in the way development is regulated are not as important in determining the built form as are private market forces.

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This thesis examines contemporary mediated spectacles used in regional tourism strategies. In recent years there has been growing occurrence of ‘formatted entertainment models’ in China. With this in mind, this thesis explores the ways in which traditional cultural resources are being converted to generate diverse, hybrid commodities. The unique business model of Zhang Yimou, known as the Impression Series provides the case study. The thesis examines multilayered representations of products which continuously form, and are formatted, under the logic of the cultural market. The case study highlights the revival of traditional Chinese culture, a new branding of the Chinese national image and rising ‘soft power’. Primarily, the thesis argues that personal celebrity endorsement is replacing political propaganda heroes in promoting an alternative image of China. Zhang Yimou and Impression West Lake function as a dual branding mechanism that combines ‘people marketing’ and ‘place marketing’ for the development of a ‘created in China’ cultural commodity as well as for the generation of positive economic outcomes. Secondly, the thesis identifies how natural resources linked with a local tourism industry are articulated into cultural products and how this is experienced by visitors. Culture is a core component of China’s ‘soft power.’ Cultural experience’ strategies such as Impression combine global marketing and local cultural forces. The thesis argues that a creative entrepreneur has more advantages in promoting ‘soft power’ than governmental propaganda strategies. Thirdly, Impression West Lake encapsulates the rise of the creative entrepreneur with the help of local government authorities. Even though government cultural policy-makers can facilitate the cultural infrastructure, they ultimately rely on the entrepreneur’s creative vision and understanding of the market. Finally, based on the study of Impression West Lake, the thesis outlines future opportunities for social, cultural and economic reform in China.

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In this paper we describe the dynamic simulation of an 18 degrees of freedom hexapod robot with the objective of developing control algorithms for smooth, efficient and robust walking in irregular terrain. This is to be achieved by using force sensors in addition to the conventional joint angle sensors as proprioceptors. The reaction forces on the feet of the robot provide the necessary information on the robots interaction with the terrain. As a first step we validate the simulator by implementing movement control by joint torques using PID controllers. As an unexpected by-product we find that it is simple to achieve robust walking behaviour on even terrain for a hexapod with the help of PID controllers and by specifying a trajectory of only a few joint configurations.

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Chapter aims By the end of your study of this chapter, you should be able to: - See public relations as a link between organisations and their environments - Use systems theory to guide your understanding and practical application of public relations - Understand the make up of a public relations management team within an organisation - Identify and understand how a range of internal forces including culture, and power affect the practice of public relations - Identify and understand how a range of external forces including conflict, activism and corporate social responsibility affect the practice of public relations.

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Information Technology (IT) is an important resource that facilitates growth and development in both the developed and emerging economies. The increasing forces of globalization are creating a wider digital divide between the developed and emerging economies. The smaller emerging economies are the most venerable. Intense competition for IT resources means that these emerging economies would need to acquire a deeper understanding of how to source and evaluate their IT-related efforts. This effort would put these economies in a better position to source funding from various stakeholders. This research presents a complementary approach to securing better IT-related business value in organizations in the South Pacific Island countries – a case of emerging economies. Analysis of data collected from six South Pacific Island countries suggests that organizations that invest in IT and related complementaries are able to better their business processes. The data also suggest that improved business processes lead to overall business processes improvements.

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This paper will focus on the group of people who were born between 1946 and 1962 immediately after the Second World War when servicemen and women returned from the forces and started families. They have been named the baby boomers because of their numbers. In Australia it is estimated that there are four million baby boomers who are approaching retirement age. The paper raises the question of whether the attitudes we have about older workers need to change and mature. Evidence for questioning entrenched myths about older staff in the work force will be discussed.

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Examines the effects of national surveillance and local right-wing intimidation on the literary works of author Eleanor Dark during the 1940s and 1950s in Australia. Reason Dark was subjected to national surveillance and right-wing intimidation; Relationship of Dark with local and national security forces; Accusations against the Dark family; Censorship faced by writers.

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Hollywood films and television programs are watched by a global audience. While many of these productions are still made in southern California, the last twenty years have seen new production centres emerge in the US, Canada and other locations worldwide. Global Hollywood has been made possible by this growing number of Local Hollywoods: locations equipped with the requisite facilities, resources and labour, as well as the political will and tax incentives, to attract and retain high-budget, Hollywood-standard projects. This new book gives an unprecedented insight into how the Gold Coast became the first outpost of Hollywood in Australia. When a combination of forces drove Hollywood studios and producers to work outside California, the Gold Coast's unique blend of government tax support, innovative entrepreneurs and diverse natural settings made it a perfect choice to host Hollywood productions. 'Local Hollywood' makes an essential contribution to the field of film and media studies, as well as giving film buffs a behind-the-scenes tour of the film industry.