9,227 research outputs found

    The ACIGA Data Analysis programme

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    The Data Analysis programme of the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA) was set up in 1998 by the first author to complement the then existing ACIGA programmes working on suspension systems, lasers and optics, and detector configurations. The ACIGA Data Analysis programme continues to contribute significantly in the field; we present an overview of our activities.Comment: 10 pages, 0 figures, accepted, Classical and Quantum Gravity, (Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 2003

    Developments in GRworkbench

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    The software tool GRworkbench is an ongoing project in visual, numerical General Relativity at The Australian National University. Recently, GRworkbench has been significantly extended to facilitate numerical experimentation in analytically-defined space-times. The numerical differential geometric engine has been rewritten using functional programming techniques, enabling objects which are normally defined as functions in the formalism of differential geometry and General Relativity to be directly represented as function variables in the C++ code of GRworkbench. The new functional differential geometric engine allows for more accurate and efficient visualisation of objects in space-times and makes new, efficient computational techniques available. Motivated by the desire to investigate a recent scientific claim using GRworkbench, new tools for numerical experimentation have been implemented, allowing for the simulation of complex physical situations.Comment: 14 pages. To appear A. Moylan, S.M. Scott and A.C. Searle, Developments in GRworkbench. Proceedings of the Tenth Marcel Grossmann Meeting on General Relativity, editors M. Novello, S. Perez-Bergliaffa and R. Ruffini. Singapore: World Scientific 200

    Network sensitivity to geographical configuration

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    Gravitational wave astronomy will require the coordinated analysis of data from the global network of gravitational wave observatories. Questions of how to optimally configure the global network arise in this context. We have elsewhere proposed a formalism which is employed here to compare different configurations of the network, using both the coincident network analysis method and the coherent network analysis method. We have constructed a network model to compute a figure-of-merit based on the detection rate for a population of standard-candle binary inspirals. We find that this measure of network quality is very sensitive to the geographic location of component detectors under a coincident network analysis, but comparatively insensitive under a coherent network analysis.Comment: 7 pages, 4 figures, accepted for proceedings of the 4th Edoardo Amaldi conference, incorporated referees' suggestions and corrected diagra

    The Impact of the Packard Commission\u27s Recommendations on Reducing Cost Overruns in Major Defense Acquisition Programs

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    This thesis examines the impact that recommendations made by the President\u27s Blue Ribbon Commission on Defense Management, informally known as the Packard Commission, had on reducing cost overruns in major DoD acquisition programs. Cost overruns are a recurring problem in the DoD, and the study of possible effects resulting from the implementation of acquisition reform efforts such as the Packard Commission study could alter this trend. In this era of acquisition reform and downsizing it\u27s important that policy makers understand the effects past and current policies have had and are having on reducing the ever present problem of cost overruns. Conclusions drawn in this thesis may guide and direct DoD policy makers in drafting future regulations and policies. This study examined 269 contracts completed between January 1, 1988 and December 31, 1995. It was found that cost performance for contracts completed after the recommendations went into effect was poorer than cost performance prior to the change. It was also found that a more significant difference occurred between contracts in development phases than those in production phases. In fact, percentage cost overruns for development contracts nearly tripled after the policy went into effect. Possible explanations and implications of this discovery are provided

    Using sports infrastructure to deliver economic and social change: Lessons for London beyond 2012

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    Over the last two decades, there has been a new trend emerging within sport, which has seen a shift, from investment for the sake of sport, to investment in sport for good (Sport England, 2008). In the context of the latter approach, there has been an emergence of the use of sport to address regeneration objectives, largely stemming from the belief of government and other sporting and non-sporting organizations, that it can confer a wide range of economic and social benefits to individuals and communities beyond those of a purely physical sporting nature, and can contribute positively to the revitalization of declining urban areas (BURA, 2003). This commentary will examine regeneration legacy in the context of the London Olympic Games. In particular, it will focus on the use of sports stadia as a tool for delivering economic and social change, and by drawing upon previous examples, suggest lessons London can learn to enhance regeneration legacies beyond 2012

    Targeted search for continuous gravitational waves: Bayesian versus maximum-likelihood statistics

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    We investigate the Bayesian framework for detection of continuous gravitational waves (GWs) in the context of targeted searches, where the phase evolution of the GW signal is assumed to be known, while the four amplitude parameters are unknown. We show that the orthodox maximum-likelihood statistic (known as F-statistic) can be rediscovered as a Bayes factor with an unphysical prior in amplitude parameter space. We introduce an alternative detection statistic ("B-statistic") using the Bayes factor with a more natural amplitude prior, namely an isotropic probability distribution for the orientation of GW sources. Monte-Carlo simulations of targeted searches show that the resulting Bayesian B-statistic is more powerful in the Neyman-Pearson sense (i.e. has a higher expected detection probability at equal false-alarm probability) than the frequentist F-statistic.Comment: 12 pages, presented at GWDAW13, to appear in CQ

    Property-based welfare and the search for generational equality

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    In many countries, the demographic shift towards an ageing population is occurring against a backdrop of welfare state restructuring. The paradigm of asset-based welfare may become increasingly central to these developments as individualised welfare is touted as part of the response to the challenge of funding the care of an ageing population. This article focuses on the framing of housing wealth as a form of asset-based welfare in the UK context. We consider the strengths and weaknesses of housing as a form of asset-based welfare, both in terms of equity between generations and equality within them. We argue that housing market gains have presented many homeowners with significant, and arguably unearned, wealth and that policy-makers could reasonably expect that some of these assets be utilised to meet welfare needs in later life. However, the suitability of asset-based welfare as a panacea to the fiscal costs of an ageing population and welfare state retraction is limited by a number of potential practical and ethical concerns

    Host Community Voices and Community Experiences: Tanzanian Perspectives on a Teacher Education International Service-Learning Project

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    Teacher education programs are increasingly integrating aspects of international service-learning (ISL) into student experience. While studies about teacher-candidate experiences are published, less is known about the effects of these ISL initiatives on the host communities. There is a need to hear from and integrate host community voices into all dimensions of the ISL experiences. We honor the voices of ISL host participants by turning our attention to those involved in an ongoing ISL project in Tanzania. Our analysis is grounded in our experiences as ISL practitioners and teacher educators. We utilize the concepts of Freire and Dewey to provide an understanding of ISL in teacher education that emphasizes how dialogue with host participants increases understanding of local contexts and promotes reciprocity as a form of learning from one another. This study concludes with the implications, both negative and positive, associated with integrating ISL into teacher education programs

    Molecular Beams

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    Contains a report on a research project

    Trust boards and governance: composition and behavioural styles

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