3,285 research outputs found

    ATTac-2000: An Adaptive Autonomous Bidding Agent

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    The First Trading Agent Competition (TAC) was held from June 22nd to July 8th, 2000. TAC was designed to create a benchmark problem in the complex domain of e-marketplaces and to motivate researchers to apply unique approaches to a common task. This article describes ATTac-2000, the first-place finisher in TAC. ATTac-2000 uses a principled bidding strategy that includes several elements of adaptivity. In addition to the success at the competition, isolated empirical results are presented indicating the robustness and effectiveness of ATTac-2000's adaptive strategy

    Alignment of Information Systems Plans with Business Plans:The Impact on Competitive Advantage

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    Under the right circumstances, the effective use of information resources can lead to competitiveadvantage. A model hypothesizes that the importance of information systems in the organization affects participation in IS planning which promotes alignment and produces greater IS-based competitive advantage. A survey of 153 CIOs was analyzed using structural equation modeling. The data supported the mode

    Bootstrapping Monte Carlo Tree Search with an Imperfect Heuristic

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    We consider the problem of using a heuristic policy to improve the value approximation by the Upper Confidence Bound applied in Trees (UCT) algorithm in non-adversarial settings such as planning with large-state space Markov Decision Processes. Current improvements to UCT focus on either changing the action selection formula at the internal nodes or the rollout policy at the leaf nodes of the search tree. In this work, we propose to add an auxiliary arm to each of the internal nodes, and always use the heuristic policy to roll out simulations at the auxiliary arms. The method aims to get fast convergence to optimal values at states where the heuristic policy is optimal, while retaining similar approximation as the original UCT in other states. We show that bootstrapping with the proposed method in the new algorithm, UCT-Aux, performs better compared to the original UCT algorithm and its variants in two benchmark experiment settings. We also examine conditions under which UCT-Aux works well.Comment: 16 pages, accepted for presentation at ECML'1

    Calibration of liquid argon and neon detectors with 83Krm^{83}Kr^m

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    We report results from tests of 83^{83}Krm^{\mathrm{m}}, as a calibration source in liquid argon and liquid neon. 83^{83}Krm^{\mathrm{m}} atoms are produced in the decay of 83^{83}Rb, and a clear 83^{83}Krm^{\mathrm{m}} scintillation peak at 41.5 keV appears in both liquids when filling our detector through a piece of zeolite coated with 83^{83}Rb. Based on this scintillation peak, we observe 6.0 photoelectrons/keV in liquid argon with a resolution of 6% (σ\sigma/E) and 3.0 photoelectrons/keV in liquid neon with a resolution of 19% (σ\sigma/E). The observed peak intensity subsequently decays with the 83^{83}Krm^{\mathrm{m}} half-life after stopping the fill, and we find evidence that the spatial location of 83^{83}Krm^{\mathrm{m}} atoms in the chamber can be resolved. 83^{83}Krm^{\mathrm{m}} will be a useful calibration source for liquid argon and neon dark matter and solar neutrino detectors.Comment: 7 pages, 12 figure

    Type II Seesaw Dominance in Non-supersymmetric and Split Susy SO(10) and Proton Life Time

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    Recently type II seesaw dominance in a supersymmetric SO(10) framework has been found useful in explaining large solar and atmospheric mixing angles as well as larger values of theta13theta_{13} while unifying quark and lepton masses. An important question in these models is whether there exists consistency between coupling unification and type II seesaw dominance. Scenarios where this consistency can be demonstrated have been given in a SUSY framework. In this paper we give examples where type II dominance occurs in SO(10) models without supersymmetry but with additional TeV scale particles and also in models with split-supersummetry. Grand unification is realized in a two-step process via breaking of SO(10) to SU(5) and then to a TeV scale standard model supplemented by extra fields and an SU(5) Higgs multiplet 15H{15}_H at a scale about 101210^{12} GeV to give type-II seesaw. The predictions for proton lifetime in these models are in the range τp0=2×1035\tau_p^0 = 2\times 10^{35} yrs. to τp0=6×1035\tau_p^0 = 6\times 10^{35} yrs.. A number of recent numerical fits to GUT-scale fermion masses can be accommodated within this model.Comment: 7 pages LaTeX, 3 figures, related areas: hep-ex, hep-th, astro-ph; Reference added, typo corrected, version to appear in Physical Review

    A General Analysis of Corrections to the Standard See-saw Formula in Grand Unified Models

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    In realistic grand unified models there are typically extra vectorlike matter multiplets at the GUT scale that are needed to explain the family hierarchy. These contain neutrinos that, when integrated out, can modify the usual neutrino see-saw formula. A general analysis is given. It is noted that such modifications can explain why the neutrinos do not exhibit a strong family hierarchy like the other types of fermions.Comment: 30 page

    Fragile three-dimensionality in the quasi-one-dimensional cuprate PrBa_2Cu_4O_8

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    In this article we report on the experimental realization of dimensional crossover phenomena in the chain compound PrBa2_2Cu4_4O8_8 using temperature, high magnetic fields and disorder as independent tuning parameters. In purer crystals of PrBa2_2Cu4_4O8_8, a highly anisotropic three-dimensional Fermi-liquid state develops at low temperatures. This metallic state is extremely susceptible to disorder however and localization rapidly sets in. We show, through quantitative comparison of the relevant energy scales, that this metal/insulator crossover occurs precisely when the scattering rate within the chain exceeds the interchain hopping rate(s), i.e. once carriers become confined to a single conducting element.Comment: 12 pages, 5 figures, published at http://www.iop.org/EJ/article/1367-2630/8/9/172/njp6_9_172.htm

    Clinical pharmacology as a foundation for translational science.

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    The evolution of enabling technologies and their associated perspectives into molecular mechanisms underlying disease has extended beyond the abilities of scientific and clinical structures to advance their translation into new algorithms that improve the health of patients and populations.1 Research programs have yielded a vast array of novel molecules related to pathophysiological mechanisms that represent diagnostic and therapeutic targets which have the potential for personalized healthcare management. Yet, despite extraordinary scientific advances, routine successful translation of discovery into new therapeutic tools remains a distant vision. Beyond constraints in bridging discovery science with clinical translation due to obstacles in facilities, resources and in skilled specialized investigators, 95% of therapies brought into product development by the pharmaceutical and biotechnology sector eventually fail, reflecting negative balance between efficacy and adverse effects

    The cost-effectiveness of changes to the care pathway used to identify depression and provide treatment amongst people with diabetes in England: a model-based economic evaluation.

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    BACKGROUND: Diabetes is associated with premature death and a number of serious complications. The presence of comorbid depression makes these outcomes more likely and results in increased healthcare costs. The aim of this work was to assess the health economic outcomes associated with having both diabetes and depression, and assess the cost-effectiveness of potential policy changes to improve the care pathway: improved opportunistic screening for depression, collaborative care for depression treatment, and the combination of both. METHODS: A mathematical model of the care pathways experienced by people diagnosed with type-2 diabetes in England was developed. Both an NHS perspective and wider social benefits were considered. Evidence was taken from the published literature, identified via scoping and targeted searches. RESULTS: Compared with current practice, all three policies reduced both the time spent with depression and the number of diabetes-related complications experienced. The policies were associated with an improvement in quality of life, but with an increase in health care costs. In an incremental analysis, collaborative care dominated improved opportunistic screening. The incremental cost-effectiveness ratio (ICER) for collaborative care compared with current practice was £10,798 per QALY. Compared to collaborative care, the combined policy had an ICER of £68,017 per QALY. CONCLUSIONS: Policies targeted at identifying and treating depression early in patients with diabetes may lead to reductions in diabetes related complications and depression, which in turn increase life expectancy and improve health-related quality of life. Implementing collaborative care was cost-effective based on current national guidance in England

    Notorious places: image, reputation, stigma: the role of newspapers in area reputations for social housing estates

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    This paper reviews work in several disciplines to distinguish between image, reputation and stigma. It also shows that there has been little research on the process by which area reputations are established and sustained through transmission processes. This paper reports on research into the portrayal of two social housing estates in the printed media over an extended period of time (14 years). It was found that negative and mixed coverage of the estates dominated, with the amount of positive coverage being very small. By examining the way in which dominant themes were used by newspapers in respect of each estate, questions are raised about the mode of operation of the press and the communities' collective right to challenge this. By identifying the way regeneration stories are covered and the nature of the content of positive stories, lessons are drawn for programmes of area transformation. The need for social regeneration activities is identified as an important ingredient for changing deprived-area reputations
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