3,285 research outputs found
ATTac-2000: An Adaptive Autonomous Bidding Agent
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
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
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
We report results from tests of Kr, as a calibration
source in liquid argon and liquid neon. Kr atoms are
produced in the decay of Rb, and a clear Kr
scintillation peak at 41.5 keV appears in both liquids when filling our
detector through a piece of zeolite coated with Rb. Based on this
scintillation peak, we observe 6.0 photoelectrons/keV in liquid argon with a
resolution of 6% (/E) and 3.0 photoelectrons/keV in liquid neon with a
resolution of 19% (/E). The observed peak intensity subsequently decays
with the Kr half-life after stopping the fill, and we
find evidence that the spatial location of Kr atoms in
the chamber can be resolved. Kr 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
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 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 at a scale about
GeV to give type-II seesaw. The predictions for proton lifetime in
these models are in the range yrs. to 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
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
In this article we report on the experimental realization of dimensional
crossover phenomena in the chain compound PrBaCuO using
temperature, high magnetic fields and disorder as independent tuning
parameters. In purer crystals of PrBaCuO, 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.
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.
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
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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