5,540 research outputs found

    System Design and Architecture of an Online, Adaptive, and Personalized Learning Platform

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    The authors propose that personalized learning can be brought to traditional and nontraditional learners through a new type of asynchronous learning platform called Guided Learning Pathways (GLP). The GLP platform allows learners to intelligently traverse a vast field of learning resources, emphasizing content only of direct relevance to the learner and presenting it in a way that matches the learnerā€™s pedagogical preference and contextual interests. GLP allows learners to advance towards individual learning goals at their own pace, with learning materials catered to each learnerā€™s interests and motivations. Learning communities would support learners moving through similar topics. This report describes the software system design and architecture required to support Guided Learning Pathways. The authors provide detailed information on eight software applications within GLP, including specific learning benefits and features of each. These applications include content maps, learning nuggets, and nugget recommendation algorithms. A learner scenario helps readers visualize the functionality of the platform. To describe the platformā€™s software architecture, the authors provide conceptual data models, process flow models, and service group definitions. This report also provides a discussion on the potential social impact of GLP in two areas: higher education institutions and the broader economy

    An Asynchronous, Personalized Learning Platformā€•Guided Learning Pathways (GLP)

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    The authors propose that personalized learning can be brought to traditional and non-traditional learners through asynchronous learning platform that recommends to individual learners the learning materials best suited for him or her. Such a platform would allow learners to advance towards individual learning goals at their own pace, with learning materials catered to each learnerā€™s interests and motivations. This paper describes the authorsā€™ vision and design for a modular, personalized learning platform called Guided Learning Pathways (GLP), and its characteristics and features. We provide detailed descriptions of and propose frameworks for critical modules like the Content Map, Learning Nuggets, and Recommendation Algorithms. A threaded user scenario is provided for each module to help the reader visualize different aspects of GLP. We discuss work done at MIT to support such a platform

    System design and architecture of an online, adaptive, and personalized learning platform

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    Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 76-82).The author proposes that personalized learning can be brought to traditional and nontraditional learners through a new type of asynchronous learning platform called Guided Learning Pathways (GLP). The GLP platform allows learners to intelligently traverse a vast field of learning resources, emphasizing content only of direct relevance to the learner and presenting it in a way that matches the learner's pedagogical preference and contextual interests. GLP allows learners to advance towards individual learning goals at their own pace, with learning materials catered to each learner's interests and motivations. Learning communities would support learners moving through similar topics. This thesis describes the software system design and architecture required to support Guided Learning Pathways. The author provides detailed information on eight software applications within GLP, including specific learning benefits and features of each. These applications include content maps, learning nuggets, and nugget recommendation algorithms. A learner scenario helps readers visualize the functionality of the platform. To describe the platform's software architecture, the author provides conceptual data models, process flow models, and service group definitions. This thesis also provides a discussion on the potential social impact of GLP in two areas: higher education institutions and the broader economy.by Cole J. Shaw.S.M.in Technology and Polic

    Obesity and metabolic syndrome in adolescent survivors of standard risk childhood acute lymphoblastic leukemia in Saudi Arabia

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    This study estimated prevalence of unhealthy weight status and metabolic syndrome (MS) amongst Saudi survivors of standard risk ALL. Procedure. We recruited 56 survivors, mean age 13.4 years (SD 4.1), a mean of 9.1 years (SD 4.1) postdiagnosis. The BMI for age was used to deļ¬ne weight status relative to national (Saudi) and international (Cole et al., Cole-IOTF, WHO, and CDC) reference data. We measured body composition by dualenergy X-ray absorptiometry (DXA), waist circumference, blood pressure, lipid proļ¬le (HDL-C, Triglycerides), fasting glucose and insulin. Results. According to international deļ¬nitions based on BMI for age, around half of the sample had unhealthy weight status. All of the approaches based on BMI for age underestimated overfatness, present in 27/51 (53%) of the sample according to DXA. Prevalence of MS was 7.1% (3/42 of those over 9-years old) and 5.4% (3/56) by applying the International Diabetes Federation (IDF) deļ¬nition and National Cholesterol Education Program Third Adult Treatment panel Guidelines (NCEP III), respectively. However, MS by the NCEP III deļ¬nition was present in 19% of the overweight and obese survivors and 7.1% of the sample had at least two of the components of MS. Conclusion. Unhealthy body weight and overfatness may be common amongst adolescent Saudi survivors of standard risk ALL, though overweight and obesity may be no more common than in the general Saudi adolescent population. Deļ¬ning weight status using BMI underestimates overfatness. Ideally, body composition and cardiometabolic risk factors should be monitored at late effects clinics. Pediatr Blood Cancer 2012;59: 133ā€“137. 2011 Wiley Periodicals, Inc

    The Local Effects of Cosmological Variations in Physical 'Constants' and Scalar Fields I. Spherically Symmetric Spacetimes

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    We apply the method of matched asymptotic expansions to analyse whether cosmological variations in physical `constants' and scalar fields are detectable, locally, on the surface of local gravitationally bound systems such as planets and stars, or inside virialised systems like galaxies and clusters. We assume spherical symmetry and derive a sufficient condition for the local time variation of the scalar fields that drive varying constants to track the cosmological one. We calculate a number of specific examples in detail by matching the Schwarzschild spacetime to spherically symmetric inhomogeneous Tolman-Bondi metrics in an intermediate region by rigorously construction matched asymptotic expansions on cosmological and local astronomical scales which overlap in an intermediate domain. We conclude that, independent of the details of the scalar-field theory describing the varying `constant', the condition for cosmological variations to be measured locally is almost always satisfied in physically realistic situations. The proof of this statement provides a rigorous justification for using terrestrial experiments and solar system observations to constrain or detect any cosmological time variations in the traditional `constants' of Nature.Comment: 30 pages, 3 figures; corrected typo

    Transport strategy in Scotland since devolution

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    This article critically reviews how the Scottish Executive's approach to transport has developed since devolution. Although there is much to commend, a number of concerns can be identified, including the possibility that a number of strategic infrastructure schemes appear to have been approved on political rather than on technical grounds. It is difficult to know whether the current set of transport infrastructure investment plans represents good value for public money

    The Impact of Cluster Structure and Dynamical State on Scatter in the Sunyaev-Zel'dovich Flux-Mass Relation

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    Cosmological constraints from cluster surveys rely on accurate mass estimates from the mass-observable relations. In order to avoid systematic biases and reduce uncertainties, we study the form and physical origin of the intrinsic scatter about the mean Sunyaev-Zel'dovich (SZ) flux-mass relation using a hydrodynamical simulation of galaxy cluster formation. We examine the assumption of lognormal scatter and detect non-negligible positive skewness and kurtosis (> 0.5) for a wide range of limiting masses and redshifts. These higher-order moments should be included in the parametrization of scatter in order not to bias cosmological constraints. We investigate the sources of the scatter by correlating it with measures of cluster morphology, halo concentration, and dynamical state, and we quantify the individual contribution from each source. We find that statistically the impact of dynamical state is weak, so the selection bias due to mergers is negligible. On the other hand, there is a strong correlation between the scatter and halo concentration, which can be used to reduce the scatter significantly (from 12.07% to 7.34% or by ~40% for clusters at z = 0). We also show that a cross-calibration by combining information from X-ray followups can be used to reduce the scatter in the flux-mass relation and also identify outliers in both X-ray and SZ cluster surveys.Comment: 14 pages, 12 figures; accepted for publication in Ap

    Reassessing Ethnic Differences in Mean BMI and Changes Between 2007 and 2013 in English Children.

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    OBJECTIVE: National body fatness (BF) data for English South Asian and Black children use BMI, which provides inaccurate ethnic comparisons. BF levels and time trends in the English National Child Measurement Programme (NCMP) between 2007 and 2013 were assessed by using ethnic-specific adjusted BMI (aBMI) for South Asian and Black children. METHODS: Analyses were based on 3,195,323 children aged 4 to 5 years and 2,962,673 children aged 10 to 11 years. aBMI values for South Asian and Black children (relating to BF as in White children) were derived independently. Mean aBMI levels and 5-year aBMI changes were obtained by using linear regression. RESULTS: In the 2007-2008 NCMP, mean aBMIs in 10- to 11-year-old children (boys, girls) were higher in South Asian children (20.1, 19.9 kg/m2 ) and Black girls, but not in Black boys (18.4, 19.2 kg/m2 ) when compared with White children (18.6, 19.0 kg/m2 ; all Pā€‰<ā€‰0.001). Mean 5-year changes (boys, girls) were higher in South Asian children (0.16, 0.32 kg/m2 per 5 y; both Pā€‰<ā€‰0.001) and Black boys but not girls (0.13, 0.15 kg/m2 per 5 y; Pā€‰=ā€‰0.01, Pā€‰=ā€‰0.41) compared with White children (0.02, 0.11 kg/m2 per 5 y). Ethnic differences at 4 to 5 years were similar. Unadjusted BMI showed similar 5-year changes but different mean BMI patterns. CONCLUSIONS: BF levels were higher in South Asian children than in other groups in 2007 and diverged from those in White children until 2013, a pattern not apparent from unadjusted BMI data

    The Impact of Halo Properties, Energy Feedback and Projection Effects on the Mass-SZ Flux Relation

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    We present a detailed analysis of the intrinsic scatter in the integrated SZ effect - cluster mass (Y-M) relation, using semi-analytic and simulated cluster samples. Specifically, we investigate the impact on the Y-M relation of energy feedback, variations in the host halo concentration and substructure populations, and projection effects due to unresolved clusters along the line of sight (the SZ background). Furthermore, we investigate at what radius (or overdensity) one should measure the integrated SZE and define cluster mass so as to achieve the tightest possible scaling. We find that the measure of Y with the least scatter is always obtained within a smaller radius than that at which the mass is defined; e.g. for M_{200} (M_{500}) the scatter is least for Y_{500} (Y_{1100}). The inclusion of energy feedback in the gas model significantly increases the intrinsic scatter in the Y-M relation due to larger variations in the gas mass fraction compared to models without feedback. We also find that variations in halo concentration for clusters of a given mass may partly explain why the integrated SZE provides a better mass proxy than the central decrement. Substructure is found to account for approximately 20% of the observed scatter in the Y-M relation. Above M_{200} = 2x10^{14} h^{-1} msun, the SZ background does not significantly effect cluster mass measurements; below this mass, variations in the background signal reduce the optimal angular radius within which one should measure Y to achieve the tightest scaling with M_{200}.Comment: 12 pages, 6 figures, to be submitted to Ap
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