971 resultados para Edith Patch
Resumo:
Ocean processes are dynamic, complex, and occur on multiple spatial and temporal scales. To obtain a synoptic view of such processes, ocean scientists collect data over long time periods. Historically, measurements were continually provided by fixed sensors, e.g., moorings, or gathered from ships. Recently, an increase in the utilization of autonomous underwater vehicles has enabled a more dynamic data acquisition approach. However, we still do not utilize the full capabilities of these vehicles. Here we present algorithms that produce persistent monitoring missions for underwater vehicles by balancing path following accuracy and sampling resolution for a given region of interest, which addresses a pressing need among ocean scientists to efficiently and effectively collect high-value data. More specifically, this paper proposes a path planning algorithm and a speed control algorithm for underwater gliders, which together give informative trajectories for the glider to persistently monitor a patch of ocean. We optimize a cost function that blends two competing factors: maximize the information value along the path, while minimizing deviation from the planned path due to ocean currents. Speed is controlled along the planned path by adjusting the pitch angle of the underwater glider, so that higher resolution samples are collected in areas of higher information value. The resulting paths are closed circuits that can be repeatedly traversed to collect long-term ocean data in dynamic environments. The algorithms were tested during sea trials on an underwater glider operating off the coast of southern California, as well as in Monterey Bay, California. The experimental results show significant improvements in data resolution and path reliability compared to previously executed sampling paths used in the respective regions.
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Objective: This paper asks whether Indigenous health policies might be improved if governments listened to Indigenous voices, both Australian and those who drafted the Declaration on the Rights of Indigenous Peoples, 2007. Methods: A fundamental tenet of the Declaration, which Australia endorsed in 2009, is respect for Indigenous knowledge and voice. The author analyses legal, cultural and historical sources for evidence of this respect. The metaphorical and empirical framework of the analysis is the epidemic of otitis media among Indigenous children. Results: A survey of Indigenous advice about health clearly demonstrates that access to their land and respect for the diversity of Indigenous cultures should inform health policies. Despite, however, claiming to consult Indigenous peoples, policy-makers have not been listening. In many Indigenous languages not listening, or ‘bad ears’, has connotations of disrespect. Conclusions: By turning a deaf ear to Indigenous knowledge governments are undermining any respect Indigenous peoples may have for them and their policies. A new approach is needed. Implications: The Declaration on the Rights of Indigenous Peoples can provide federal, state and territory governments with benchmarks against which health policy can be developed and implemented. Authentic consultation could restore Indigenous confidence in government policies.
Resumo:
Almost all metapopulation modelling assumes that connectivity between patches is only a function of distance, and is therefore symmetric. However, connectivity will not depend only on the distance between the patches, as some paths are easy to traverse, while others are difficult. When colonising organisms interact with the heterogeneous landscape between patches, connectivity patterns will invariably be asymmetric. There have been few attempts to theoretically assess the effects of asymmetric connectivity patterns on the dynamics of metapopulations. In this paper, we use the framework of complex networks to investigate whether metapopulation dynamics can be determined by directly analysing the asymmetric connectivity patterns that link the patches. Our analyses focus on “patch occupancy” metapopulation models, which only consider whether a patch is occupied or not. We propose three easily calculated network metrics: the “asymmetry” and “average path strength” of the connectivity pattern, and the “centrality” of each patch. Together, these metrics can be used to predict the length of time a metapopulation is expected to persist, and the relative contribution of each patch to a metapopulation’s viability. Our results clearly demonstrate the negative effect that asymmetry has on metapopulation persistence. Complex network analyses represent a useful new tool for understanding the dynamics of species existing in fragmented landscapes, particularly those existing in large metapopulations.
Resumo:
In this paper, we seek to expand the use of direct methods in real-time applications by proposing a vision-based strategy for pose estimation of aerial vehicles. The vast majority of approaches make use of features to estimate motion. Conversely, the strategy we propose is based on a MR (Multi- Resolution) implementation of an image registration technique (Inverse Compositional Image Alignment ICIA) using direct methods. An on-board camera in a downwards-looking configuration, and the assumption of planar scenes, are the bases of the algorithm. The motion between frames (rotation and translation) is recovered by decomposing the frame-to-frame homography obtained by the ICIA algorithm applied to a patch that covers around the 80% of the image. When the visual estimation is required (e.g. GPS drop-out), this motion is integrated with the previous known estimation of the vehicles’ state, obtained from the on-board sensors (GPS/IMU), and the subsequent estimations are based only on the vision-based motion estimations. The proposed strategy is tested with real flight data in representative stages of a flight: cruise, landing, and take-off, being two of those stages considered critical: take-off and landing. The performance of the pose estimation strategy is analyzed by comparing it with the GPS/IMU estimations. Results show correlation between the visual estimation obtained with the MR-ICIA and the GPS/IMU data, that demonstrate that the visual estimation can be used to provide a good approximation of the vehicle’s state when it is required (e.g. GPS drop-outs). In terms of performance, the proposed strategy is able to maintain an estimation of the vehicle’s state for more than one minute, at real-time frame rates based, only on visual information.
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This paper formulates a node-based smoothed conforming point interpolation method (NS-CPIM) for solid mechanics. In the proposed NS-CPIM, the higher order conforming PIM shape functions (CPIM) have been constructed to produce a continuous and piecewise quadratic displacement field over the whole problem domain, whereby the smoothed strain field was obtained through smoothing operation over each smoothing domain associated with domain nodes. The smoothed Galerkin weak form was then developed to create the discretized system equations. Numerical studies have demonstrated the following good properties: NS-CPIM (1) can pass both standard and quadratic patch test; (2) provides an upper bound of strain energy; (3) avoid the volumetric locking; (4) provides the higher accuracy than those in the node-based smoothed schemes of the original PIMs.
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How can Australian library and information science (LIS) education produce, in a sustainable manner, the diverse supply of graduates with the appropriate attributes to develop and maintain high quality professional practice in the rapidly changing 21st century? This report presents the key findings of a project that has examined this question through research into future directions for LIS education in Australia. Titled Re-conceptualising and re-positioning Australian library and information science education for the twenty-first century, the purpose of the project was to establish a consolidated and holistic picture of the Australian LIS profession, and identify how its future education and training can be mediated in a cohesive and sustainable manner. The project was undertaken with a team of 12 university and vocational LIS educators from 11 institutions around Australia between November 2009 and December 2010. Collectively, these eleven institutions represented the broad spectrum and diversity of LIS education in Australia, and enabled the project to examine education for the information profession in a holistic and synergistic manner. Participating institutions in the project included Queensland University of Technology (Project Leader), Charles Sturt University, Curtin University of Technology, Edith Cowan University, Monash University, RMIT University, University of Canberra, University of South Australia, University of Tasmania, University of Technology Sydney and Victoria University. The inception and need for the project was motivated by a range of factors. From a broad perspective several of these factors relate to concerns raised at national and international levels regarding problems with education for LIS. In addition, the motivation and need for the project also related to some unique challenges that LIS education faces in the Australian tertiary education landscape. Over recent years a range of responses to explore the various issues confronting LIS education in Australia have emerged at local and national levels however this project represented the first significant investment of funding for national research in this area. In this way, the inception of the project offered a unique opportunity and powerful mechanism through which to bring together key stakeholders and inspire discourse concerning future education for the profession. Therefore as the first national project of its kind, its intent has been to provide foundation research that will inform and guide future directions for LIS education and training in Australia. The primary objective of the project was to develop a Framework for the Education of the Information Professions in Australia. The purpose of this framework was to provide evidence based strategic recommendations that would guide Australia’s future education for the information professions. Recognising the three major and equal players in the education process the project was framed around three areas of consideration: LIS students, the LIS workforce and LIS educators. Each area of consideration aligned to a research substudy in the project. The three research substudies were titled Student Considerations, Workforce Planning Considerations and Tertiary Education Considerations. The Students substudy provided a profile of LIS students and an analysis of their choices, experiences and expectations in regard to LIS education and their graduate destinations. The Workforce substudy provided an overview and analysis of the nature of the current LIS workforce, including a focus on employer expectations and employment opportunities and comment on the core and elective skill, knowledge and attitudes of current and future LIS professionals. Finally the Tertiary Education substudy provided a profile of LIS educators and an analysis of their characteristics and experiences including the key issues and challenges. In addition it also explored current national and international trends and priorities impacting on LIS education. The project utilised a Community Based Participatory Research (CBPR) approach. This approach involves all members of the community in all aspects of the project. It recognised the unique strengths and perspectives that community members bring to the process. For this project ‘community’ comprised of all individuals who have a role in, or a vested interest in, LIS education and included LIS educators, professionals, employers, students and professional associations. Individuals from these sub-groups were invited to participate in a range of aspects of the project from design through to implementation and evaluation. A range of research methodologies were used to consider the many different perspectives of LIS education, including employers and recruiters, professional associations, students, graduates and LIS teaching staff. Data collection involved a mixed method approach of questionnaires, focus groups, semi-structured interviews and environmental scans. An array of approaches was selected to ensure that broadest possible access to different facets of the information profession would be achieved. The main findings and observations from each substudy have highlighted a range of challenges for LIS education that need to be addressed. These findings and observations have grounded the development of the Framework for the Education of the Information Professions in Australia. The framework presents eleven recommendations to progress the national approach to LIS education and guide Australia’s future education for the information professions. The framework will be used by the LIS profession, most notably its educators, as strategic directions for the future of LIS education in Australia. Framework for the Education of the Information Professions in Australia: Recommendation 1: It is recommended that a broader and more inclusive vocabulary be adopted that both recognises and celebrates the expanding landscape of the field, for example ‘information profession’, ‘information sector’, ‘information discipline’ and ‘information education’. Recommendation 2: It is recommended that a self-directed body composed of information educators be established to promote, support and lead excellence in teaching and research within the information discipline. Recommendation 3: It is recommended that Australia’s information discipline continue to develop excellence in information research that will raise the discipline’s profile and contribute to its prominence within the national and international arena. Recommendation 4: It is recommended that further research examining the nature and context of Australia’s information education programs be undertaken to ensure a sustainable and relevant future for the discipline. Recommendation 5: It is recommended that further research examining the pathways and qualifications available for entry into the Australian information sector be undertaken to ensure relevance, attractiveness, accessibility and transparency. Recommendation 6: It is recommended that strategies are developed and implemented to ensure the sustainability of the workforce of information educators. Recommendation 7: It is recommended that a national approach to promoting and marketing the information profession and thereby attracting more students to the field is developed. Recommendation 8: It is recommended that Australia’s information discipline continues to support a culture of quality teaching and learning, especially given the need to accommodate a focus on the broader information landscape and more flexible delivery options. Recommendation 9: It is recommended that strategies are developed that will support and encourage collaboration between information education within the higher education and VET sectors. Recommendation 10: It is recommended that strategies and forums are developed that will support the information sector working together to conceptualise and articulate their professional identity and educational needs. Recommendation 11: It is recommended that a research agenda be established that will identify and prioritise areas in which further development or work is needed to continue advancing information education in Australia. The key findings from this project confirm that a number of pressing issues are confronting LIS education in Australia. Left unaddressed these issues will have significant implications for the future of LIS education as well as the broader LIS profession. Consequently creating a sustainable and cohesive future can only be realised through cooperation and collaboration among all stakeholders including those with the capacity to enact radical change in university and vocational institutions. Indeed the impending adoption and implementation of the project’s recommendations will fundamentally determine whether Australian LIS education is assured both for the present day and into the future.
Resumo:
An SEI metapopulation model is developed for the spread of an infectious agent by migration. The model portrays two age classes on a number of patches connected by migration routes which are used as host animals mature. A feature of this model is that the basic reproduction ratio may be computed directly, using a scheme that separates topography, demography, and epidemiology. We also provide formulas for individual patch basic reproduction numbers and discuss their connection with the basic reproduction ratio for the system. The model is applied to the problem of spatial spread of bovine tuberculosis in a possum population. The temporal dynamics of infection are investigated for some generic networks of migration links, and the basic reproduction ratio is computed—its value is not greatly different from that for a homogeneous model. Three scenarios are considered for the control of bovine tuberculosis in possums where the spatial aspect is shown to be crucial for the design of disease management operations
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Background: The most common functional single nucleotide polymorphism of the human OPRM1 gene, A118G, has been shown to be associated with interindividual differences in opioid analgesic requirements, particularly with morphine, in patients with acute postoperative pain. The purpose of this study was to examine whether this polymorphism would modulate the morphine and fentanyl pharmacological profile of sensory neurons isolated from a humanized mouse model homozygous for either the 118A or 118G allele. Methods: The coupling of wild-type and mutant μ opioid receptors to voltage-gated Ca channels after exposure to either ligand was examined by employing the whole cell variant of the patch-clamp technique in acutely dissociated trigeminal ganglion neurons. Morphine-mediated antinociception was measured in mice carrying either the 118AA or 118GG allele. RESULTS:: The biophysical parameters (cell size, current density, and peak current amplitude potential) measured from both groups of sensory neurons were not significantly different. In 118GG neurons, morphine was approximately fivefold less potent and 26% less efficacious than that observed in 118AA neurons. On the other hand, the potency and efficacy of fentanyl were similar for both groups of neurons. Morphine-mediated analgesia in 118GG mice was significantly reduced compared with the 118AA mice. Conclusions: This study provides evidence to suggest that the diminished clinical effect observed with morphine in 118G carriers results from an alteration of the receptor's pharmacology in sensory neurons. In addition, the impaired analgesic response with morphine may explain why carriers of this receptor variant have an increased susceptibility to become addicted to opioids. © 2011 the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins. Anesthesiology.
Resumo:
A 2-element elliptical patch antenna array with a bi-directional radiation pattern has been developed for ultra wideband indoor wireless communications. The array is constructed by means of feeding two omni-directional elliptical patch elements with a 3-section hybrid power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1 - 6 GHz).
Resumo:
Due to proliferation of online stores prior expectations that retailing would move completely online were not fulfilled. Previous research about consumers’ preference of retailing channels suggested that online sales are driven by the convenience of online shopping, or as a natural extension of online searches. This paradigm has changed over the years. Changes in consumer behaviour are indicating that while consumers are searching online using various information sources to learn about products, ultimately when purchasing, consumers are shifting between online and offline retailing channels depending on various factors. Online shopping is still considered to be a convenient way to purchase goods, but the convenience is not the key factor. This qualitative research is based on 22 in-depth interviews with shoppers in Australia.
Resumo:
Global and national agendas for quality education have led to reforms in Papua New Guinea’s (PNG) elementary education, but criticism of the learner-centred, Western pedagogies has emerged. One key influence on quality teacher education relates to perspectives of teaching. Existing research shows teachers’ beliefs and perceptions of teaching influence their practice, however to date little research has investigated perspectives of teaching for elementary education in PNG. This single exploratory case study investigated the perspectives of teaching for eighteen elementary teacher trainers as they studied for a Bachelor of Early Childhood (Teacher Education). The study, drawing on an interpretivist paradigm, analysed journals and course planning documents using a thematic approach. The findings revealed that while the trainers’ perspectives of teaching children tended to reflect a learning-centred perspective (focused on what the teacher does), their perspectives of teaching adults were both learning-centred and learner-centred (what the learner does). Based on these findings, a culturally connected perspective of teaching is advocated for PNG elementary teacher education. This perspective enables the co-existence of both the learning-centred and learner-centred perspectives of teaching in the PNG cultural context and has implications for teacher education and the communities involved in elementary education in general.
Resumo:
his paper formulates an edge-based smoothed conforming point interpolation method (ES-CPIM) for solid mechanics using the triangular background cells. In the ES-CPIM, a technique for obtaining conforming PIM shape functions (CPIM) is used to create a continuous and piecewise quadratic displacement field over the whole problem domain. The smoothed strain field is then obtained through smoothing operation over each smoothing domain associated with edges of the triangular background cells. The generalized smoothed Galerkin weak form is then used to create the discretized system equations. Numerical studies have demonstrated that the ES-CPIM possesses the following good properties: (1) ES-CPIM creates conforming quadratic PIM shape functions, and can always pass the standard patch test; (2) ES-CPIM produces a quadratic displacement field without introducing any additional degrees of freedom; (3) The results of ES-CPIM are generally of very high accuracy.
Resumo:
Odometry is an important input to robot navigation systems, and we are interested in the performance of vision-only techniques. In this paper we experimentally evaluate and compare the performance of wheel odometry, monocular feature-based visual odometry, monocular patch-based visual odometry, and a technique that fuses wheel odometry and visual odometry, on a mobile robot operating in a typical indoor environment.
Resumo:
The railhead is severely stressed under the localized wheel contact patch close to the gaps in insulated rail joints. A modified railhead profile in the vicinity of the gapped joint, through a shape optimization model based on a coupled genetic algorithm and finite element method, effectively alters the contact zone and reduces the railhead edge stress concentration significantly. Two optimization methods, a grid search method and a genetic algorithm, were employed for this optimization problem. The optimal results from these two methods are discussed and, in particular, their suitability for the rail end stress minimization problem is studied. Through several numerical examples, the optimal profile is shown to be unaffected by either the magnitude or the contact position of the loaded wheel. The numerical results are validated through a large-scale experimental study.
Resumo:
Virtual worlds (VWs) continue to be used extensively in Australia and New Zealand higher education institutions although the tendency towards making unrealistic claims of efficacy and popularity appears to be over. Some educators at higher education institutions continue to use VWs in the same way as they have done in the past; others are exploring a range of different VWs or using them in new ways; whilst some are opting out altogether. This paper presents an overview of how 46 educators from some 26 institutions see VWs as an opportunity to sustain higher education. The positives and negatives of using VWs are discussed.