429 research outputs found

    Overview of the personalized and collaborative information retrieval (PIR) track at FIRE-2011

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    The Personalized and collaborative Information Retrieval (PIR) track at FIRE 2011 was organized with an aim to extend standard information retrieval (IR) ad-hoc test collection design to facilitate research on personalized and collaborative IR by collecting additional meta-information during the topic (query) development process. A controlled query generation process through task-based activities with activity logging was used for each topic developer to construct the final list of topics. The standard ad-hoc collection is thus accompanied by a new set of thematically related topics and the associated log information. We believe this can better simulate a real-world search scenario and encourage mining user information from the logs to improve IR effectiveness. A set of 25 TREC formatted topics and the associated metadata of activity logs were released for the participants to use. In this paper we illustrate the data construction phase in detail and also outline two simple ways of using the additional information from the logs to improve retrieval effectiveness

    Overview of the CLEF 2018 personalised information retrieval lab (PIR-CLEF 2018)

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    At CLEF 2018, the Personalised Information Retrieval Lab (PIR-CLEF 2018) has been conceived to provide an initiative aimed at both providing and critically analysing a new approach to the evaluation of personalization in Information Retrieval (PIR). PIR-CLEF 2018 is the first edition of this Lab after the successful Pilot lab organised at CLEF 2017. PIR CLEF 2018 has provided registered participants with the data sets originally developed for the PIR-CLEF 2017 Pilot task; the data collected are related to real search sessions over a subset of the ClueWeb12 collection, undertaken by 10 users by using a novel methodology. The data were gathered during the search sessions undertaken by 10 volunteer searchers. Activities during these search sessions included relevance assessment of a retrieved documents by the searchers. 16 groups registered to participate at PIR-CLEF 2018 and were provided with the data set to allow them to work on PIR related tasks and to provide feedback about our proposed PIR evaluation methodology with the aim to create an effective evaluation task

    Overview of the CLEF 2018 personalised information retrieval lab (PIR-CLEF 2018)

    Get PDF
    At CLEF 2018, the Personalised Information Retrieval Lab (PIR-CLEF 2018) has been conceived to provide an initiative aimed at both providing and critically analysing a new approach to the evaluation of personalization in Information Retrieval (PIR). PIR-CLEF 2018 is the first edition of this Lab after the successful Pilot lab organised at CLEF 2017. PIR CLEF 2018 has provided registered participants with the data sets originally developed for the PIR-CLEF 2017 Pilot task; the data collected are related to real search sessions over a subset of the ClueWeb12 collection, undertaken by 10 users by using a novel methodology. The data were gathered during the search sessions undertaken by 10 volunteer searchers. Activities during these search sessions included relevance assessment of a retrieved documents by the searchers. 16 groups registered to participate at PIR-CLEF 2018 and were provided with the data set to allow them to work on PIR related tasks and to provide feedback about our proposed PIR evaluation methodology with the aim to create an effective evaluation task

    The JCMT Legacy Survey of the Gould Belt: a first look at Orion B with HARP

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society.The Gould Belt Legacy Survey will survey nearby star-forming regions (within 500 pc), using Heterodyne Array Receiver Programme (HARP), Submillimetre Common-User Bolometer Array 2 and Polarimeter 2 on the James Clerk Maxwell Telescope. This paper describes the initial data obtained using HARP to observe 12CO, 13CO and C18O J= 3 → 2 towards two regions in Orion B, NGC 2024 and NGC 2071. We describe the physical characteristics of the two clouds, calculating temperatures and opacities utilizing all the three isotopologues. We find good agreement between temperatures calculated from CO and from dust emission in the dense, energetic regions. We determine the mass and energetics of the clouds, and of the high-velocity material seen in 12CO emission, and compare the relative energetics of the high- and low-velocity material in the two clouds. We present a clumpfind analysis of the 13CO condensations. The slope of the condensation mass functions, at the high-mass ends, is similar to the slope of the initial mass function.Peer reviewe

    Non-linear Dynamics in QED_3 and Non-trivial Infrared Structure

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    In this work we consider a coupled system of Schwinger-Dyson equations for self-energy and vertex functions in QED_3. Using the concept of a semi-amputated vertex function, we manage to decouple the vertex equation and transform it in the infrared into a non-linear differential equation of Emden-Fowler type. Its solution suggests the following picture: in the absence of infrared cut-offs there is only a trivial infrared fixed-point structure in the theory. However, the presence of masses, for either fermions or photons, changes the situation drastically, leading to a mass-dependent non-trivial infrared fixed point. In this picture a dynamical mass for the fermions is found to be generated consistently. The non-linearity of the equations gives rise to highly non-trivial constraints among the mass and effective (`running') gauge coupling, which impose lower and upper bounds on the latter for dynamical mass generation to occur. Possible implications of this to the theory of high-temperature superconductivity are briefly discussed.Comment: 29 pages LATEX, 7 eps figures incorporated, uses axodraw style. Discussion on the massless case (section 2) modified; no effect on conclusions, typos correcte

    Physics Opportunities with the 12 GeV Upgrade at Jefferson Lab

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    This white paper summarizes the scientific opportunities for utilization of the upgraded 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab. It is based on the 52 proposals recommended for approval by the Jefferson Lab Program Advisory Committee.The upgraded facility will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics.Comment: 64 page

    Search for supersymmetry with a dominant R-parity violating LQDbar couplings in e+e- collisions at centre-of-mass energies of 130GeV to 172 GeV

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    A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQDbar coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130-172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m_0=500 GeV/c^2 and tan(beta)=sqrt(2) charginos with masses smaller than 81 GeV/c^2 and neutralinos with masses smaller than 29 GeV/c^2 are excluded at the 95% confidence level for any generation structure of the LQDbar coupling.Comment: 32 pages, 30 figure

    Detecting and Studying the Lightest Pseudo-Goldstone Boson at Future pppp, e+ee^+e^- and μ+μ\mu^+\mu^- Colliders

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    For an attractive class of dynamical symmetry breaking (technicolor) models, the lightest neutral pseudo-Nambu-Goldstone boson (\pzero) contains only down-type techniquarks and charged technileptons. We discuss the prospects for discovering and studying the \pzero of such models at the Tevatron and the LHC and at future \epem and \mupmum colliders. Depending upon the number of technicolors, \ntc, discovery of the \pzero at the Tevatron and the LHC in the gg\to\pzero\to\gam\gam mode could be possible over a wide range of mass. For \ntc=4, discovery of the \pzero at an \epem collider via the reaction \epem\to\gam \pzero should be possible as long as \mpzero is not near \mz. In the \gam\gam collider mode of operation at an \epem collider, the \gam\gam\to\pzero\to b\anti b signal should be very robust if \ntc=4. For the minimal \ntc=1 case, detection of the \pzero at the Tevatron and in \epem collisions will be very difficult, and the precision of measurements at the LHC and the \gam\gam collider decline markedly. A \mupmum collider yields a \pzero production rate that does not depend markedly upon \ntc. At a \mupmum collider discovery of the \pzero as an ss-channel resonance should prove possible via scanning, even if it has not already been detected elsewhere. Once \mpzero is precisely known, operation of the \mupmum collider as a \pzero factory will allow precision measurements of enough observables to determine the number of technicolors of the theory and (up to a discrete set of ambiguities) the fundamental parameters of the low-energy effective Lagrangian describing the Yukawa couplings of the \pzero.Comment: 54 pages, latex equations.sty, 21 figures; revised to include results for NTC=1N_{TC}=1 as well as NTC=4N_{TC}=4, and other minor changes to yield correspondence to final published versio

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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