429 resultados para meson-exchange model


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The Howard East rural area has experienced a rapid growth of small block subdivisions and horticulture over the last 40 years, which has been based on groundwater supply. Early bores in the area provide part of the water supply for Darwin City and are maintained and monitored by NT Power & Water Corporation. The Territory government (NRETAS) has established a monitoring network, and now 48 bores are monitored. However, in the area there are over 2700 private bores that are unregulated.Although NRETAS has both FDM and FEM simulations for the region, community support for potential regulation is sought. To improve stakeholder understanding of the resource QUT was retained by the TRaCKconsortium to develop a 3D visualisation of the groundwater system.

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Biased estimation has the advantage of reducing the mean squared error (MSE) of an estimator. The question of interest is how biased estimation affects model selection. In this paper, we introduce biased estimation to a range of model selection criteria. Specifically, we analyze the performance of the minimum description length (MDL) criterion based on biased and unbiased estimation and compare it against modern model selection criteria such as Kay's conditional model order estimator (CME), the bootstrap and the more recently proposed hook-and-loop resampling based model selection. The advantages and limitations of the considered techniques are discussed. The results indicate that, in some cases, biased estimators can slightly improve the selection of the correct model. We also give an example for which the CME with an unbiased estimator fails, but could regain its power when a biased estimator is used.

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Modern computer graphics systems are able to construct renderings of such high quality that viewers are deceived into regarding the images as coming from a photographic source. Large amounts of computing resources are expended in this rendering process, using complex mathematical models of lighting and shading. However, psychophysical experiments have revealed that viewers only regard certain informative regions within a presented image. Furthermore, it has been shown that these visually important regions contain low-level visual feature differences that attract the attention of the viewer. This thesis will present a new approach to image synthesis that exploits these experimental findings by modulating the spatial quality of image regions by their visual importance. Efficiency gains are therefore reaped, without sacrificing much of the perceived quality of the image. Two tasks must be undertaken to achieve this goal. Firstly, the design of an appropriate region-based model of visual importance, and secondly, the modification of progressive rendering techniques to effect an importance-based rendering approach. A rule-based fuzzy logic model is presented that computes, using spatial feature differences, the relative visual importance of regions in an image. This model improves upon previous work by incorporating threshold effects induced by global feature difference distributions and by using texture concentration measures. A modified approach to progressive ray-tracing is also presented. This new approach uses the visual importance model to guide the progressive refinement of an image. In addition, this concept of visual importance has been incorporated into supersampling, texture mapping and computer animation techniques. Experimental results are presented, illustrating the efficiency gains reaped from using this method of progressive rendering. This visual importance-based rendering approach is expected to have applications in the entertainment industry, where image fidelity may be sacrificed for efficiency purposes, as long as the overall visual impression of the scene is maintained. Different aspects of the approach should find many other applications in image compression, image retrieval, progressive data transmission and active robotic vision.

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UCON is an emerging access control framework that lacks an administration model. In this paper we define the problem of administration and propose a novel administrative model. At the core of this model is the concept of attribute, which is also the central component of UCON. In our model, attributes are created by the assertions of subjects, which ascribe properties/rights to other subjects or objects. Through such a treatment of attributes, administration capabilities can be delegated from one subject to another and as a consequence UCON is improved in three aspects. First, immutable attributes that are currently considered as external to the model can be incorporated and thereby treated as mutable at- tributes. Second, the current arbitrary categorisation of users (as modifiers of attributes), to system and administrator can be removed. Attributes and objects are only modifiable by those who possess administration capability over them. Third, the delegation of administration over objects and properties that is not currently expressible in UCON is made possible.

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Most online assessment systems now incorporate social networking features, and recent developments in social media spaces include protocols that allow the synchronisation and aggregation of data across multiple user profiles. In light of these advances and the concomitant fear of data sharing in secondary school education this papers provides important research findings about generic features of online social networking, which educators can use to make sound and efficient assessments in collaboration with their students and colleagues. This paper reports on a design experiment in flexible educational settings that challenges the dichotomous legacy of success and failure evident in many assessment activities for at-risk youth. Combining social networking practices with the sociology of education the paper proposes that assessment activities are best understood as a negotiable field of exchange. In this design experiment students, peers and educators engage in explicit, "front-end" assessment (Wyatt-Smith, 2008) to translate digital artefacts into institutional, and potentiality economic capital without continually referring to paper based pre-set criteria. This approach invites students and educators to use social networking functions to assess “work in progress” and final submissions in collaboration, and in doing so assessors refine their evaluative expertise and negotiate the value of student’s work from which new criteria can emerge. The mobile advantages of web-based technologies aggregate, externalise and democratise this transparent assessment model for most, if not all, student work that can be digitally represented.

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This paper discusses the use of models in automatic computer forensic analysis, and proposes and elaborates on a novel model for use in computer profiling, the computer profiling object model. The computer profiling object model is an information model which models a computer as objects with various attributes and inter-relationships. These together provide the information necessary for a human investigator or an automated reasoning engine to make judgements as to the probable usage and evidentiary value of a computer system. The computer profiling object model can be implemented so as to support automated analysis to provide an investigator with the information needed to decide whether manual analysis is required.

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The periosteum plays an indispensable role in both bone formation and bone defect healing. In this study we constructed an artificial in vitro periosteum by incorporating osteogenic differentiated bone marrow stromal cells (BMSCs) and cobalt chloride (CoCl(2))-treated BMSCs. The engineered periostea were implanted both subcutaneously and into skull bone defects in SCID mice to investigate ectopic and orthotopic osteogenesis and vascularization. After two weeks in subcutaneous and four weeks in bone defect areas, the implanted constructs were assessed for ectopic and orthotopic osteogenesis and vascularization by micro-CT, histomorphometrical and immunohistochemical methods. The results showed that CoCl(2) pre-treated BMSCs induced higher degree of vascularization and enhanced osteogenesis within the implants in both ectopic and orthotopic areas. This study provided a novel approach using BMSCs sourced from the same patient for both osteogenic and pro-angiogenic purposes in constructing tissue engineered periosteum to enhance vascularized osteogenesis.

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The critical impact of innovation on national and the global economies has been discussed at length in the literature. Economic development requires the diffusion of innovations into markets. It has long been recognised that economic growth and development depends upon a constant stream of innovations. Governments have been keenly aware of the need to ensure this flow does not dry to a trickle and have introduced many and varied industry policies and interventions to assist in seeding, supporting and diffusing innovations. In Australia, as in many countries, Government support for the transfer of knowledge especially from publicly funded research has resulted in the creation of knowledge exchange intermediaries. These intermediaries are themselves service organisations, seeking innovative service offerings for their markets. The choice for most intermediaries is generally a dichotomous one, between market-pull and technology-push knowledge exchange programmes. In this article, we undertake a case analysis of one such innovative intermediary and its flagship programme. We then compare this case with other successful intermediaries in Europe. We put forward a research proposition that the design of intermediary programmes must match the service type they offer. That is, market-pull programmes require market-pull design, in close collaboration with industry, whereas technology programmes can be problem-solving innovations where demand is latent. The discussion reflects the need for an evolution in knowledge transfer policies and programmes beyond the first generation ushered in with the US Bayh-Dole Act (1980) and Stevenson-Wydler Act (1984). The data analysed is a case study comparison of market-pull and technology-push programmes, focusing on primary and secondary socio-economic benefits (using both Australian and international comparisons).

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This study explores strategic decision-making (SDM) in micro-firms, an economically significant business subsector. As extant large- and small-firm literature currently proffers an incomplete characterization of SDM in very small enterprises, a multiple-case methodology was used to investigate how these firms make strategic decisions. Eleven Australian Information Technology service micro-firms participated in the study. Using an information-processing lens, the study uncovered patterns of SDM in micro-firms and derived a theoretical micro-firm SDM model. This research also identifies several implications for micro-firm management and directions for future research, contributing to the understanding of micro-firm SDM in both theory and practice.

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Despite more than three decades of research, there is a limited understanding of the transactional processes of appraisal, stress and coping. This has led to calls for more focused research on the entire process that underlies these variables. To date, there remains a paucity of such research. The present study examined Lazarus and Folkman’s (1984) transactional model of stress and coping. One hundred and twenty nine Australian participants with full time employment (i.e. nurses and administration employees) were recruited. There were 49 male (age mean = 34, SD = 10.51) and 80 female (age mean = 36, SD = 10.31) participants. The analysis of three path models indicated that in addition to the original paths, which were found in Lazarus and Folkman’s transactional model (primary appraisal-->secondary appraisal-->stress-->coping), there were also direct links between primary appraisal and stress level time one and between stress level time one to stress level time two. This study has provided additional insights into the transactional process which will extend our understanding of how individuals appraise, cope and experience occupational stress.

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Purpose: Relationship trust and commitment are two key dimensions of international exchanges. Both have been extensively investigated from an exporter (as opposed to importer) perspective in developed country (as opposed to developing country) contexts. To address these gaps, this study aims to develop a model of antecedents and outcomes of importer trust and commitment in two developing countries.---------- Design/methodology: The authors test the proposed model using data from Chile and Bangladesh. Hypotheses were tested using structural equation modeling (SEM).---------- Findings: SEM analysis revealed that most of the hypotheses were supported in both the Bangladeshi and Chilean context. The findings of this study also suggest that the effects of importer transaction-specific investments on importer commitment are distinct in the Bangladeshi context. Practical implications: Practically, these results show that trust and commitment are essential for enhancing importer relationship performance in developing countries. Importer trust in a foreign supplier is effective when suppliers are competent and provide relatively superior facilities, as opposed to opportunistic proclivity. Importer commitment to a foreign supplier is stronger when importers perceive that the foreign supplier is not opportunistic, but is knowledgeable and experienced with the importer market, and they perceive that it is an advantage importing from that supplier. Cultural similarity between importers and foreign suppliers improves importer trust in both countries. However, importer commitment in Chile increases with importer transaction-specific investment, but this is not found to be the case in Bangladesh.---------- Originality/value: This study contributes to the importer-exporter exchange relationship literature by testing a model of antecedents and outcomes of importer trust and commitment. The tested model is one of few that considers developing country contexts and incorporates two novel antecedents of trust and commitment: importer knowledge and experience, and supplier resource competency.

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The increase of life expectancy worldwide during the last three decades has increased age-related disability leading to the risk of loss of quality of life. How to improve quality of life including physical health and mental health for older people and optimize their life potential has become an important health issue. This study used the Theory of Planned Behaviour Model to examine factors influencing health behaviours, and the relationship with quality of life. A cross-sectional mailed survey of 1300 Australians over 50 years was conducted at the beginning of 2009, with 730 completed questionnaires returned (response rate 63%). Preliminary analysis reveals that physiological changes of old age, especially increasing waist circumference and co morbidity was closely related to health status, especially worse physical health summary score. Physical activity was the least adherent behaviour among the respondents compared to eating healthy food and taking medication regularly as prescribed. Increasing number of older people living alone with co morbidity of disease may be the barriers that influence their attitude and self control toward physical activity. A multidisciplinary and integrated approach including hospital and non hospital care is required to provide appropriate services and facilities toward older people.

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This report documents Stage Two of the Australian ePortfolio Project (AeP2), to specifically explore the current scope of national and international ePortfolio communities of practice in order to identify the factors that have contributed to their success and sustainability. The study has built on Stage One of the Australian ePortfolio Project (Hallam, Harper, McCowan, Hauville, McAllister, & Creagh, 2008), which outlined the broad range of issues and challenges, as well as significant opportunities, that faced the higher education sector in terms of ePortfolio practice, to determine how the emergent community of ePortfolio researchers and practitioners in Australia might be advanced. ---------- The overarching aims of this project were to focus on building the Australian community of practice through an online forum and further symposium activities. Through the research activities the project sought to generate the following major outcomes: develop a forum within the ALTC Exchange to support an ePortfolio community of practice; develop strategies to encourage interest in and engagement with community of practice activities; develop and promote resources to support the diverse stakeholders in ePortfolio practice; collaborate in the establishment of a cross-sector ePortfolio community of practice; host a second Australian ePortfolio Symposium (AeP2) to disseminate the findings from the Australian ePortfolio Project, to explore innovative practice in ePortfolio use in higher education, to articulate policy developments, and to stimulate discussion on international ePortfolio issues; host an associated trade display as a forum for strengthening the higher education sector’s understanding of the features and functionality of ePortfolio platforms; develop resources to support an ePortfolio symposium model that may be adopted for future events. ----------- The project activities encompassed a survey of stakeholders, a program of semi-structured interviews with community managers and a series of case studies depicting successful ePortfolio communities. The survey of ePortfolio practitioners sought to determine the potential value of an ePortfolio CoP, the preferred focus for and the desired features of such a community, as well as the options for the technical and social architecture of an online forum. Through the semi-structured interviews it was possible to examine current examples of CoP activity, to identify the critical success factors and the challenges faced by individual ePortfolio CoPs, so that the attributes of good practice could be presented. The data collected in the interviews contributed to the development of 14 case studies, which have been beneficial in illustrating the diverse nature of CoPs in Australia and overseas.----------- The report presents a rich picture of national and international ePortfolio communities of practice, with an examination of the factors that have contributed to their success and sustainability.

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Emerging market importers are increasingly engaging in relationships with foreign suppliers. Nevertheless, characteristics of the institutional and cultural environments of countries may affect relationship behaviour. Furthermore research on relationship marketing primarily focuses on the marketing activities of exporters from developed countries and much less attention is paid to the import side of the exchange process. Thus, the objective of this study is to empirically examine importer relationship performance in a Latin America context. This article proposes and tests a conceptual model that includes the antecedents and outcomes of trust and commitment with a survey of Chilean importers. The model uses confirmatory factor analysis (CFA) to develop the construct measures and structural equation modelling (SEMS) to test the model. The findings of this study contribute to a better understanding of the driving forces of trust and commitments and their influence on importing firms' performance in an emerging market context.