944 resultados para Influential observation


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There are large uncertainties in the aerothermodynamic modelling of super-orbital re-entry which impact the design of spacecraft thermal protection systems (TPS). Aspects of the thermal environment of super-orbital re-entry flows can be simulated in the laboratory using arc- and plasma jet facilities and these devices are regularly used for TPS certification work [5]. Another laboratory device which is capable of simulating certain critical features of both the aero and thermal environment of super-orbital re-entry is the expansion tube, and three such facilities have been operating at the University of Queensland in recent years[10]. Despite some success, wind tunnel tests do not achieve full simulation, however, a virtually complete physical simulation of particular re-entry conditions can be obtained from dedicated flight testing, and the Apollo era FIRE II flight experiment [2] is the premier example which still forms an important benchmark for modern simulations. Dedicated super-orbital flight testing is generally considered too expensive today, and there is a reluctance to incorporate substantial instrumentation for aerothermal diagnostics into existing missions since it may compromise primary mission objectives. An alternative approach to on-board flight measurements, with demonstrated success particularly in the ‘Stardust’ sample return mission, is remote observation of spectral emissions from the capsule and shock layer [8]. JAXA’s ‘Hayabusa’ sample return capsule provides a recent super-orbital reentry example through which we illustrate contributions in three areas: (1) physical simulation of super-orbital re-entry conditions in the laboratory; (2) computational simulation of such flows; and (3) remote acquisition of optical emissions from a super-orbital re entry event.

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Community-based treatment and care of people with psychiatric disabilities has meant that they are now more likely to engage in the parenting role. This has led to the development of programs designed to enhance the parenting skills of people with psychiatric disabilities. Evaluation of these programs has been hampered by a paucity of evaluation tools. This study's aim was to develop and trial a tool that examined the parent-child interaction within a group setting, was functional and easy to use, required minimum training and equipment, and had acceptable levels of reliability and validity. The revised tool yielded a single scale with acceptable reliability. It had discriminative validity and concurrent validity with non-independent global ratings of parenting. Sensitivity to change was not investigated. The findings suggest that this method of evaluating parenting is likely to have both clinical and research utility and further investigation of the psychometric properties of the tool is warranted.

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This article examines, from both within and outside the context of compulsory third party motor vehicle insurance, the different academic and judicial perspectives regarding the relevance of insurance to the imposition of negligence liability via the formulation of legal principle. In particular, the utility of insurance in setting the standard of care held owing by a learner driver to an instructor in Imbree v McNeilly is analysed and the implications of this High Court decision, in light of current jurisprudential argument and for other principles of negligence liability, namely claimant vulnerability, are considered. It concludes that ultimately one’s stance as to the relevance, or otherwise, of insurance to the development of the common law of negligence will be predominately influenced by normative views of torts’ function as an instrument of corrective or distributive justice.

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This thesis explores the business environment for self-publishing musicians at the end of the 20th century and the start of the 21st century from theoretical and empirical standpoints. The exploration begins by asking three research questions: what are the factors affecting the sustainability of an Independent music business; how many of those factors can be directly influenced by an Independent musician in the day-to-day operations of their musical enterprise; and how can those factors be best manipulated to maximise the benefit generated from digital music assets? It answers these questions by considering the nature of value in the music business in light of theories of political economy, then quantitative and qualitative examinations of the nature of participation in the music business, and then auto-ethnographic approaches to the application of two technologically enabled tools available to Independent musicians. By analyzing the results of five different examinations of the topic it answers each research question with reference to four sets of recurring issues that affect the operations of a 21st century music business: the musicians’ personal characteristics, their ability to address their business’s informational needs; their ability to manage the relationships upon which their business depends; and their ability to resolve the remaining technological problems that confront them. It discusses ways in which Independent self-publishing musicians can and cannot deal with these four issues on a day-to-day basis and highlights aspects for which technological solutions do not exist as well as ways in which technology is not as effective as has been claimed. It then presents a self-critique and proposes some directions for further study before concluding by suggesting some common features of 21st century Independent music businesses. This thesis makes three contributions to knowledge. First, it provides a new understanding of the sources of musical value, shows how this explains changes in the music industries over the past 30 years, and provides a framework for predicting future developments in those industries. Second, it shows how the technological discontinuity that has occurred around the start of the 21st century has and has not affected the production and distribution of digital cultural artefacts and thus the attitudes, approaches, and business prospects of Independent musicians. Third, it argues for new understandings of two methods by which self-publishing musicians can grow a business using production methods that are only beginning to be more broadly understood: home studio recording and fan-sourced production. Developed from the perspective of working musicians themselves, this thesis identifies four sets of issues that determine the probable success of musicians’ efforts to adopt new technologies to capture the value of the musicians’ creativity and thereby foster growth that will sustain an Independent music business in the 21st century.

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Establishing a persistent presence in the ocean with an AUV to observe temporal variability of large-scale ocean processes requires a unique sensor platform. In this paper, we propose a strategy that utilizes ocean model predictions to increase the autonomy and control of Lagrangian or profiling floats for precisely this purpose. An A* planner is applied to a local controllability map generated from predictions of ocean currents to compute a path between prescribed waypoints that has the highest likelihood of successful execution. The control to follow the planned path is computed by use of a model predictive controller. This controller is designed to select the best depth for the vehicle to exploit ambient currents to reach the goal waypoint. Mission constraints are employed to simulate a practical data collection mission. Results are presented in simulation for a mission off the coast of Los Angeles, CA USA, and show surprising results in the ability of a Lagrangian float to reach a desired location.

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The aim of this study was to characterise the new particle formation events in a subtropical urban environment in the southern hemisphere. The study measured the number concentration of particles and its size distribution in Brisbane, Australia during 2009. The variation of particle number concentration and nucleation burst events were characterised as well as the particle growth rate which was first reported in urban environment of Australia. The annual average NUFP, NAitken and NNuc were 9.3 x 103, 3.7 x 103 and 5.6 x 103 cm-3, respectively. Weak seasonal variation in number concentration was observed. Local traffic exhaust emissions were a major contributor of the pollution (NUFP) observed in morning which was dominated by the Aitken mode particles, while particles formed by secondary formation processes contributed to the particle number concentration during afternoon. Overall, 65 nucleation burst events were identified during the study period. Nucleation burst events were classified into two groups, with and without particles growth after the burst of nucleation mode particles observed. The average particle growth rate of the nucleation events was 4.6 nm hr-1 (ranged from 1.79 – 7.78 nm hr-1). Case studies of the nucleation burst events were characterised including i) the nucleation burst with particle growth which is associated with the particle precursor emitted from local traffic exhaust emission, ii) the nucleation burst without particle growth which is due to the transport of industrial emissions from the coast to Brisbane city or other possible sources with unfavourable conditions which suppressed particle growth and iii) interplay between the above two cases which demonstrated the impact of the vehicle and industrial emissions on the variation of particle number concentration and its size distribution during the same day.

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Objective(s): A new model of care for the management of patients with delirium was developed and evaluated. Method: A 4-bedded Close Observation Unit (COU) was introduced. The model comprised an education strategy for assistants in nursing (AIN), environmental adaptations and AIN to patient ratio of 1:4. Outcomes in all patients with delirium before and after introduction of the new model of care were compared. Results: 105 patients were admitted to COU, of whom 100 (95%) were diagnosed with delirium. In-hospital mortality improved after introduction of the unit (15% versus 5%; p=0.002) without significant change in length of stay, discharge destination or falls frequency. Conclusion: A dedicated unit for delirium management within medicine achieved a reduction in mortality.

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The 2011 floods in Southeast Queensland had a devastating impact on many sectors including transport. Road and rail systems across all flooded areas of Queensland were severely affected and significant economic losses occurred as a result of roadway and railway closures. Travellers were compelled to take alternative routes because of road closures or deteriorated traffic conditions on their regular route. Extreme changes in traffic volume can occur under such scenarios which disrupts the network re-equilibrium and re-stabilisation in the recovery phase as travellers continuously adjust their travel options. This study explores how travellers respond to such a major network disruption. A comprehensive study was undertaken focusing on how bus riders reacted to the floods in Southeast Queensland by comparing the ridership patterns before, during and after the floods. The study outcomes revealed the evolving reactions of transit users to direct and indirect impacts of a natural disaster. A good understanding of this process is crucial for developing appropriate strategies to encourage modal shift of automobile users to public transit and also for modelling of travel behaviours during and after a major network disruption caused by natural disasters.

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Establishing a persistent presence in the ocean with an autonomous underwater vehicle (AUV) capable of observing temporal variability of large-scale ocean processes requires a unique sensor platform. In this paper, we examine the utility of vehicles that can only control their depth in the water column for such extended deployments. We present a strategy that utilizes ocean model predictions to facilitate a basic level of autonomy and enables general control for these profiling floats. The proposed method is based on experimentally validated techniques for utilizing ocean current models to control autonomous gliders. With the appropriate vertical actuation, and utilizing spatio–temporal variations in water speed and direction, we show that general controllability results can be met. First, we apply an A* planner to a local controllability map generated from predictions of ocean currents. This computes a path between start and goal waypoints that has the highest likelihood of successful execution. A computed depth plan is generated with a model-predictive controller (MPC), and selects the depths for the vehicle so that ambient currents guide it toward the goal. Mission constraints are included to simulate and motivate a practical data collection mission. Results are presented in simulation for a mission off the coast of Los Angeles, CA, USA, that show encouraging results in the ability of a drifting vehicle to reach a desired location.

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Morphology changes induced in polycrystalline silver catalysts as a result of heating in either oxygen, water or oxygen-methanol atmospheres have been investigated by environmental scanning electron microscopy (ESEM), FT-Raman spectroscopy and temperature programmed desorption (TPD). The silver catalyst of interest consisted of two distinct particle types, one of which contained a significant concentration of sub-surface hydroxy species (in addition to surface adsorbed atomic oxygen). Heating the sample to 663 K resulted in the production of 'pin-holes' in the silver structure as a consequence of near-surface explosions caused by sub-surface hydroxy recombination. Furthermore, 'pin-holes' were predominantly found in the vicinity of surface defects, such as platelets and edge structures. Reaction between methanol and oxygen also resulted in the formation of 'pin-holes' in the silver surface, which were inherently associated with the catalytic process. A reaction mechanism is suggested that involves the interaction of methanol with sub-surface oxygen species to form sub-surface hydroxy groups. The sub-surface hydroxy species subsequently erupt through the silver surface to again produce 'pin-holes'.