11 research outputs found

    Metacognition and lifelong e-learning: a contextual and cyclical process

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    Metacognition is arguably an important conceptualisation within the area of lifelong e- learning, with many theorists and practitioners claiming that it enhances the learning process. However, the lifelong, cyclical and flexible aspects of 'before', 'during' and 'after' metacognitions within lifelong e-learning (inclusive of whether an 'input' necessarily leads to a completed 'output') seem marginal within current areas of practical and theoretical debate. This article analyses Reeves's (1997) model of web-based learning in the context of the ADAPT project; a study of lifelong learners based in small and medium sized enterprises. The article focuses upon an analysis of this model's view of metacognition, and in the light of the project findings and literature review, aims to put forward an extended and expanded version of the model with reference to lifelong e-learnin

    Hybrid and Conventional Mesons in the Flux Tube Model: Numerical Studies and their Phenomenological Implications

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    We present results from analytical and numerical studies of a flux tube model of hybrid mesons. Our numerical results use a Hamiltonian Monte Carlo algorithm and so improve on previous analytical treatments, which assumed small flux tube oscillations and an adiabatic separation of quark and flux tube motion. We find that the small oscillation approximation is inappropriate for typical hadrons and that the hybrid mass is underestimated by the adiabatic approximation. For physical parameters in the ``one-bead" flux tube model we estimate the lightest hybrid masses (ΛL=1P{}_\Lambda L = {}_1 P states) to be 1.8-1.9~GeV for uuˉu\bar u hybrids, 2.1-2.2~GeV for ssˉs\bar s and 4.1-4.2~GeV for ccˉc\bar c. We also determine masses of conventional qqˉq\bar q mesons with L=0L=0 to L=3L=3 in this model, and confirm good agreement with experimental JJ-averaged multiplet masses. Mass estimates are also given for hybrids with higher orbital and flux-tube excitations. The gap from the lightest hybrid level (1P{}_1P) to the first hybrid orbital excitation (1D{}_1D) is predicted to be 0.4\approx 0.4~GeV for light quarks (q=u,d)(q=u,d) and 0.3\approx 0.3~GeV for q=cq=c. Both 1P{}_1P and 1D{}_1D hybrid multiplets contain the exotics 1+1^{-+} and 2+2^{+-}; in addition the 1P{}_1P has a 0+0^{+-} and the 1D{}_1D contains a 3+3^{-+}. Hybrid mesons with doubly-excited flux tubes are also considered. The implications of our results for spectroscopy are discussed, with emphasis on charmonium hybrids, which may be accessible at facilities such as BEPC, KEK, a Tau-Charm Factory, and in ψ\psi production at hadron colliders.Comment: 39 pages of RevTex. Figures available via anonymous ftp at ftp://compsci.cas.vanderbilt.edu/QSM/bcsfig1.ps and /QSM/bcsfig6.p

    Perceptual identification across the life span: A dissociation of early gains and late losses

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    Waszak F, Schneider WX, Li S-C, Hommel B. Perceptual identification across the life span: A dissociation of early gains and late losses. Psychological Research. 2009;73(1):114-122.The age-correlated gains and losses in visual identification under backward pattern masking were studied in a representative sample of 226 individuals ranging from 6 to 88 years of age. Participants identified masked symbols at leisure under high and low stimulus quality and at varying Stimulus Onset Asynchronies. Performance increased from childhood to early adulthood and then decreased, describing the common inverted U-shaped function. However, measures of general processing speed accounted for the gains in childhood and adolescence but not for losses in older age. This asymmetry between child development and aging is inconsistent with general-factor lifespan theories of cognitive development and suggest that specific mechanisms underlying visual identification during child development and aging are different
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