1,415 research outputs found

    The governance of public bodies in times of austerity

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    Private sector governance arrangements have been imported into UK public bodies under the influence of New Public Management reforms. This paper draws on a cohort study of 14 public bodies to assess the appropriateness of this practice and the impact of fiscal austerity during the study period of 2010–16. Based on multiple sources, including interviews with Chairs and Chief Executives, it shows that, though similar to private corporate Boards in appearance, public Boards are often excluded from the strategy role. They are also vulnerable to the elastic definition of policy over which Ministers assert dominance, thereby blurring accountability. It demonstrates the tension between vertical accountability to government principals and horizontal accountability to stakeholders. During the study window, public bodies were abolished, broken up, merged, reconfigured or taken back into core government, as the UK Government imposed austerity measures to reduce the size of the fiscal deficit and to diminish government roles in delivery, financing and regulation of public services. Surviving public bodies in the study suffered deep budget cuts and less autonomy from central control. These findings are interpreted as evidence of the re-territorialisation of the UK public sector, with accruals accounting and accounting consolidation practices playing a facilitating role

    Computing the Distribution of a Tree Metric

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    The Robinson-Foulds (RF) distance is by far the most widely used measure of dissimilarity between trees. Although the distribution of these distances has been investigated for twenty years, an algorithm that is explicitly polynomial time has yet to be described for computing this distribution (which is also the distribution of trees around a given tree under the popular Robinson-Foulds metric). In this paper we derive a polynomial-time algorithm for this distribution. We show how the distribution can be approximated by a Poisson distribution determined by the proportion of leaves that lie in `cherries' of the given tree. We also describe how our results can be used to derive normalization constants that are required in a recently-proposed maximum likelihood approach to supertree construction.Comment: 16 pages, 3 figure

    On choosing mixture components via non-local priors

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    Choosing the number of mixture components remains an elusive challenge. Model selection criteria can be either overly liberal or conservative and return poorly-separated components of limited practical use. We formalize non-local priors (NLPs) for mixtures and show how they lead to well-separated components with non-negligible weight, interpretable as distinct subpopulations. We also propose an estimator for posterior model probabilities under local and non-local priors, showing that Bayes factors are ratios of posterior to prior empty-cluster probabilities. The estimator is widely applicable and helps set thresholds to drop unoccupied components in overfitted mixtures. We suggest default prior parameters based on multi-modality for Normal/T mixtures and minimal informativeness for categorical outcomes. We characterise theoretically the NLP-induced sparsity, derive tractable expressions and algorithms. We fully develop Normal, Binomial and product Binomial mixtures but the theory, computation and principles hold more generally. We observed a serious lack of sensitivity of the Bayesian information criterion (BIC), insufficient parsimony of the AIC and a local prior, and a mixed behavior of the singular BIC. We also considered overfitted mixtures, their performance was competitive but depended on tuning parameters. Under our default prior elicitation NLPs offered a good compromise between sparsity and power to detect meaningfully-separated components

    Measuring the associations between collaborative working and project performance

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    There is evidence that higher degrees of collaborative working can produce more successful project performance, but there is only limited research to systematically examine the specific associations between collaborative working and project performance. In particular, there is a lack of exploration of appropriate approaches to test these associations. In order to test these associations in an appropriate approach, the concepts of collaborative working and project performance in this research are transformed into a measurable form in terms of the philosophy of AHP (analytic hierarchy process). In the process of measurement design for collaborative working and project performance, a Likert Scale is adopted. After refining the final measures through unidimensionality and reliability testing, as a part of PhD study, this paper presents the results of the association exploration between collaborative working and project performance. The produced conclusion is strongly supporting that there is a strong positive linear relationship between collaborative working and project performance

    Exploring the attributes of collaborative working in construction industry

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    Due to the increased level of uncertainty of construction market and the variety of building functions, the practitioners in construction need work together more closely, which means a higher degree of collaborative working is often necessary. There is evidence that higher degree of collaborative working can produce more successful projects, but there has been only limited research to examine the definition of collaborative working. The lack of understanding of collaborative working resulted in confusion of application of more collaborative approaches e.g. partnering or alliancing. The work presented here is part of an ongoing PhD study which aims to explore the impact of collaborative working on construction project performance. The aim of this paper is to identify a spectrum of attributes of collaborative working, which will facilitate the understanding what collaborative working is, why collaborative working is needed and how to work together. In order to identify those attributes of collaborative working, the method of ‘identification test’ will be adopted, which is based on the recent related literature

    A robust lesion boundary segmentation algorithm using level set methods

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    This paper addresses the issue of accurate lesion segmentation in retinal imagery, using level set methods and a novel stopping mechanism - an elementary features scheme. Specifically, the curve propagation is guided by a gradient map built using a combination of histogram equalization and robust statistics. The stopping mechanism uses elementary features gathered as the curve deforms over time, and then using a lesionness measure, defined herein, ’looks back in time’ to find the point at which the curve best fits the real object. We compare the proposed method against five other segmentation algorithms performed on 50 randomly selected images of exudates with a database of clinician demarcated boundaries as ground truth

    Using shape entropy as a feature to lesion boundary segmentation with level sets

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    Accurate lesion segmentation in retinal imagery is an area of vast research. Of the many segmentation methods available very few are insensitive to topological changes on noisy surfaces. This paper presents an extension to earlier work on a novel stopping mechanism for level sets. The elementary features scheme (ELS) in [5] is extended to include shape entropy as a feature used to ’look back in time’ and find the point at which the curve best fits the real object. We compare the proposed extension against the original algorithm for timing and accuracy using 50 randomly selected images of exudates with a database of clinician demarcated boundaries as ground truth. While this work is presented applied to medical imagery, it can be used for any application involving the segmentation of bright or dark blobs on noisy images

    Making the governance of public bodies work : chair-chief executive relationships in practice

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    The authors gratefully acknowledge a grant from the British Academy (SG10591) and an award from the University of Aberdeen Knowledge Exchange and Transfer Fund.Peer reviewedPostprin

    1991 DA: An asteroid in a bizarre orbit

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    Asteroidal object 1991 DA has an orbit of high inclination, crossing the planets from Mars to Uranus. This is unique for an asteroid, but not unusual for a comet of the Halley-type: it therefore seems likely that 1991 DA is an extinct or dormant comet. Previous CCD imaging has shown no indication of a coma; spectroscopic observations of 1991 DA which lack any evidence of strong comet-like emissions are reported. Numerical integrations of the orbit of this object were performed which show that is has been remarkably stable for the past approximately 20,000 yr, but chaotic before that. This may allow a new estimate to be made of the physical lifetimes of comets

    Table builder problem - confidentiality for linked tables

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    The aim of this project is to investigate solutions to the problem of improving access to detailed survey data, while ensuring no person or organisation is likely to be identified, or otherwise put at risk of having their data disclosed, and to link general findings back to the ABS Table Builder problem. We focussed on making contributions in two main areas, namely: 1. Identification of sensitive cells in a table, 2. Maximizing data utility and minimising information loss - ensuring the table provides useful information
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