38,310 research outputs found

    Sustainable built asset management performance indicators and attributes : a UK social housing case study example

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    This paper aims to identify key performance indicators (KPI), and their corresponding attributes, required to successfully manage asset management sustainably in a built environment context. Improving the sustainability of existing housing stock is a major challenge facing the UK social housing sector. There is a lack of support to navigate the growing and often incongruent information relating to sustainable development and how to operationalise it. The problem is twofold; firstly, the current (single criterion) condition-based approach to maintenance planning constrains Asset Managers and does not fully address the social, environmental and economic aspects of sustainability. Secondly, the toolkits available for assessing the sustainability of housing are often generic and are time consuming and expensive to implement. This paper reports the findings of a participatory research project with a leading London based housing association, using a series of landlord and tenant workshops to derive a set of attributes associated with key performance indicators (KPIs) to fully reflect the local requirements of the landlord and their interpretation of the sustainability agenda. Five KPIs considered to be measurable, directly affected by maintenance work and independent of each other were identified by this landlord (comfort, running costs, adaptability, maintenance costs and community).The resulting outputs, in a policy context, will provide a clear route-map to social housing landlords of how to improve the sustainability of their housing stock with the additional benefits of addressing fuel poverty, carbon emissions targets whilst at the same time help create and maintain housing in which people want to live. The proposed approach is flexible enough to incorporate the individual requirements of landlords, be able to adapt to changes in government policy (local and central) in a timely, robust, transparent and inclusive format

    Wildlife Health Surveillance on the National Bison Range ā€“ Monitoring for M. Paratuberculosis in Bison

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    The wildlife health surveillance program on the National Bison Range was designed to assess the presence and prevalence of diseases in wildlife populations. Annual sampling and disease testing has been conducted at the range for decades. Starting in 2000, a statistically derived disease detection model for bison was designed and implemented to enhance detection of several diseases, including M. paratuberculosis. This disease, commonly known as Johneā€™s disease, is a bacterial intestinal disease that causes diarrhea, severe weight loss, and eventual death in bison and cattle. Targeting analysis of both populations as a whole and the status of individual animals, the program includes; (1) year-round direct observations aimed at detecting acute injuries, chronic conditions, mortalities, and emerging disease, and (2) regular diagnostic laboratory testing for a suite of diseases of particular concern and to evaluate exposure to several viral, parasitic and bacterial diseases common in the cattle industry. Information from direct observation is documented and shared with staff experienced in dealing with injuries, mortalities, and necropsies. Diagnostic analysis depends on routine coordination with our wildlife health office in Bozeman, Montana, by providing guidance concerning disease or other life-threatening conditions, and annual summary analysis of data. This is a long term adaptive process that includes periodically assessing local and regional wildlife threats, updating protocols according to sample results and providing management with necessary information to maintain healthy wildlife populations within a fenced boundary

    Longitudinal Double Spin Asymmetry in Inclusive Jet Production at STAR

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    This contribution reports on the first measurement of the longitudinal double-spin asymmetry ALLA_{LL} for the inclusive production of jets in polarized proton-proton collisions at s=200GeV\sqrt{s}=200 \mathrm{GeV}. The data were collected with STAR at RHIC in the years 2003 and 2004, and correspond to a sampled integrated luminosity of 0.3pbāˆ’10.3 \mathrm{pb}^{-1} with beam polarizations up to 45%. The results on ALLA_{LL} cover jet transverse momenta 5<pT<17GeV/c5 < p_{T} < 17 \mathrm{GeV/c} and agree with perturbative QCD evaluations based on deep-inelastic scattering parametrizations for the gluon polarization in the proton. The results disfavor large positive gluon polarization in the polarized proton.Comment: 5 pages, 1 figur

    Efficient Computation of Probabilities of Events Described by Order Statistics and Application to a Problem of Queues

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    Consider a set of N i.i.d. random variables in [0, 1]. When the experimental values of the random variables are arranged in ascending order from smallest to largest, one has the order statistics of the set of random variables. In this note an O(N3) algorithm is developed for computing the probability that the order statistics vector lies in a given rectangle. The new algorithm is then applied to a problem of statistical inference in queues. Illustrative computational results are included

    Efficient Computation of Probabilities of Events Described by Order Statistics and Applications to Queue Inference

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    This paper derives recursive algorithms for efficiently computing event probabilities related to order statistics and applies the results in a queue inferencing setting. Consider a set of N i.i.d. random variables in [0, 1]. When the experimental values of the random variables are arranged in ascending order from smallest to largest, one has the order statistics of the set of random variables. Both a forward and a backward recursive O(N3 ) algorithm are developed for computing the probability that the order statistics vector lies in a given N-rectangle. The new algorithms have applicability in inferring the statistical behavior of Poisson arrival queues, given only the start and stop times of service of all N customers served in a period of continuous congestion. The queue inference results extend the theory of the "Queue Inference Engine" (QIE), originally developed by Larson in 1990 [8]. The methodology is extended to a third O(N 3 ) algorithm, employing both forward and backward recursion, that computes the conditional probability that a random customer of the N served waited in queue less than r minutes, given the observed customer departure times and assuming first come, first served service. To our knowledge, this result is the first O(N3 ) exact algorithm for computing points on the in-queue waiting time distribution function,conditioned on the start and stop time data. The paper concludes with an extension to the computation of certain correlations of in-queue waiting times. Illustrative computational results are included throughout

    Geothermal probabilistic cost study

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    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model was used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents was analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance were examined

    Dynamical Decoupling in Optical Fibers: Preserving Polarization Qubits from Birefringent Dephasing

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    One of the major challenges in quantum computation has been to preserve the coherence of a quantum system against dephasing effects of the environment. The information stored in photon polarization, for example, is quickly lost due to such dephasing, and it is crucial to preserve the input states when one tries to transmit quantum information encoded in the photons through a communication channel. We propose a dynamical decoupling sequence to protect photonic qubits from dephasing by integrating wave plates into optical fiber at prescribed locations. We simulate random birefringent noise along realistic lengths of optical fiber and study preservation of polarization qubits through such fibers enhanced with Carr-Purcell-Meiboom-Gill (CPMG) dynamical decoupling. This technique can maintain photonic qubit coherence at high fidelity, making a step towards achieving scalable and useful quantum communication with photonic qubits.Comment: 8 pages, 5 figure

    Neuropsychological and functional outcomes in recent-onset major depression, bipolar disorder and schizophrenia-spectrum disorders: a longitudinal cohort study

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    Functional disability is the lead contributor to burden of mental illness. Cognitive deficits frequently limit functional recovery, although whether changes in cognition and disability are longitudinally associated in recent-onset individuals remains unclear. Using a prospective, cohort design, 311 patients were recruited and assessed at baseline. One hundred and sixty-seven patients met eligibility criteria (M = 21.5 years old, s.d. = 4.8) and returned for follow-up (M = 20.6 months later, s.d. = 7.8). Two-hundred and thirty participants were included in the final analysis, comprising clinically stable patients with major depression (n = 71), bipolar disorder (BD; n = 61), schizophrenia-spectrum disorders (n = 35) and 63 healthy controls. Neuropsychological functioning and self-rated functional disability were examined using mixed-design, repeated-measures analysis, across diagnoses and cognitive clusters, covarying for relevant confounds. Clinical, neuropsychological and functional changes did not differ between diagnoses (all P40.05). Three reliable neuropsychological subgroups emerged through cluster analysis, characterized by psychomotor slowing, improved sustained attention, and improved verbal memory. Controlling for diagnosis and changes in residual symptoms, clusters with improved neuropsychological functioning observed greater reductions in functional disability than the psychomotor slowing cluster, which instead demonstrated a worsening in disability (Po0.01). Improved sustained attention was independently associated with greater likelihood of follow-up employment (Po0.01). Diagnosis of BD uniquely predicted both follow-up employment and independent living. Neuropsychological course appears to be independently predictive of subjective and objective functional outcomes. Importantly, cognitive phenotypes may reflect distinct pathophysiologies shared across major psychiatric conditions, and be ideal targets for personalized early intervention

    On the anisotropic density distribution on large scales

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    Motivated by the recent detection of an enhanced clustering signal along the major axis of haloes in N-body simulations, we derive a formula for the anisotropic density distribution around haloes and voids on large scales. Our model, which assumes linear theory and that the formation and orientation of nonlinear structures are strongly correlated with the Lagrangian shear, is in good agreement with measurements. We also show that the measured amplitude is inconsistent with a model in which the alignment is produced by the initial inertia rather than shear tensor.Comment: 6 pages, 3 figures; With a moderate revision of the original version, as published in MNRA
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