25,449 research outputs found

    Development Communication: 1. History and Theories

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    This entry includes three articles, each dealing with a different aspect of the subject: History and Theories Alternative Systems Projects The first and third cover predominantly the Western (especially the U.S.) approach; the second raises some criticisms directed at both the theoretical and the practical limitations of the Western perspective and presents alternative views

    Computers, the internet, and cheating among secondary school students: Some implications for educators

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    This article investigates in greater depth one particular aspect of cheating within secondary education and some implications for measuring academic achievement. More specifically, it examines how secondary students exploit the Internet for plagiarizing schoolwork, and looks at how a traditional method of educational assessment, namely paper-based report and essay writing, has been impacted by the growth of Internet usage and the proliferation of computer skills among secondary school students. One of the conclusions is that students’ technology fluency is forcing educators to revisit conventional assessment methods. Different options for combating Internet plagiarism are presented, and some software tools as well as non-technology solutions are evaluated in light of the problems brought about by “cyberplagiarism.

    Green's functions for far-side seismic images: a polar expansion approach

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    We have computed seismic images of magnetic activity on the far surface of the Sun by using a seismic-holography technique. As in previous works, the method is based on the comparison of waves going in and out of a particular point in the Sun but we have computed here the Green's functions from a spherical polar expansion of the adiabatic wave equations in the Cowling approximation instead of using the ray-path approximation previously used in the far-side holography. A comparison between the results obtained using the ray theory and the spherical polar expansion is shown. We use the gravito-acoustic wave equation in the local plane-parallel limit in both cases and for the latter we take the asymptotic approximation for the radial dependencies of the Green's function. As a result, improved images of the far-side can be obtained from the polar-expansion approximation, especially when combining the Green's functions corresponding to two and three skips. We also show that the phase corrections in the Green's functions due to the incorrect modeling of the uppermost layers of the Sun can be estimated from the eigenfrequencies of the normal modes of oscillation.Comment: 8 pages, 5 figures, Astrophysical Journal, accepted (2010

    Littlest Inverse Seesaw Model

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    We propose a minimal predictive inverse seesaw model based on two right-handed neutrinos and two additional singlets, leading to the same low energy neutrino mass matrix as in the Littlest Seesaw (LS) (type I) model. In order to implement such a Littlest Inverse Seesaw (LIS) model, we have used an S4S_{4} family symmetry, together with other various symmetries, flavons and driving fields. The resulting LIS model leads to an excellent fit to the low energy neutrino parameters, including the prediction of a normal neutrino mass ordering, exactly as in the usual LS model. However, unlike the LS model, the LIS model allows charged lepton flavour violating (CLFV) processes and lepton conversion in nuclei within reach of the forthcoming experiments.Comment: 17 pages, 9 figures. Published versio
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