59,549 research outputs found

    Seeing the sky through Hubble's eye: The COSMOS SkyWalker

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    Large, high-resolution space-based imaging surveys produce a volume of data that is difficult to present to the public in a comprehensible way. While megapixel-sized images can still be printed out or downloaded via the World Wide Web, this is no longer feasible for images with 10^9 pixels (e.g., the Hubble Space Telescope Advanced Camera for Surveys [ACS] images of the Galaxy Evolution from Morphology and SEDs [GEMS] project) or even 10^10 pixels (for the ACS Cosmic Evolution Survey [COSMOS]). We present a Web-based utility called the COSMOS SkyWalker that allows viewing of the huge ACS image data set, even through slow Internet connections. Using standard HTML and JavaScript, the application successively loads only those portions of the image at a time that are currently being viewed on the screen. The user can move within the image by using the mouse or interacting with an overview image. Using an astrometrically registered image for the COSMOS SkyWalker allows the display of calibrated world coordinates for use in science. The SkyWalker "technique" can be applied to other data sets. This requires some customization, notably the slicing up of a data set into small (e.g., 256^2 pixel) subimages. An advantage of the SkyWalker is the use of standard Web browser components; thus, it requires no installation of any software and can therefore be viewed by anyone across many operating systems.Comment: 4 pages, 2 figures, accepted for publication in PAS

    An investigation into the perspectives of providers and learners on MOOC accessibility

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    An effective open eLearning environment should consider the target learner’s abilities, learning goals, where learning takes place, and which specific device(s) the learner uses. MOOC platforms struggle to take these factors into account and typically are not accessible, inhibiting access to environments that are intended to be open to all. A series of research initiatives are described that are intended to benefit MOOC providers in achieving greater accessibility and disabled learners to improve their lifelong learning and re-skilling. In this paper, we first outline the rationale, the research questions, and the methodology. The research approach includes interviews, online surveys and a MOOC accessibility audit; we also include factors such the risk management of the research programme and ethical considerations when conducting research with vulnerable learners. Preliminary results are presented from interviews with providers and experts and from analysis of surveys of learners. Finally, we outline the future research opportunities. This paper is framed within the context of the Doctoral Consortium organised at the TEEM'17 conference

    Higgs Boson Masses in the MSSM with Heavy Majorana Neutrinos

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    We present a full diagrammatic computation of the one-loop corrections from the neutrino/sneutrino sector to the renormalized neutral CP-even Higgs boson self-energies and the lightest Higgs boson mass, Mh, within the context of the so-called MSSM-seesaw scenario. This consists of the Minimal Supersymmetric Standard Model with the addition of massive right handed Majorana neutrinos and their supersymmetric partners, and where the seesaw mechanism is used for the lightest neutrino mass generation. We explore the dependence on all the parameters involved, with particular emphasis in the role played by the heavy Majorana scale. We restrict ourselves to the case of one generation of neutrinos/sneutrinos. For the numerical part of the study, we consider a very wide range of values for all the parameters involved. We find sizeable corrections to Mh, which are negative in the region where the Majorana scale is large (10^{13}-10^{15} GeV) and the lightest neutrino mass is within a range inspired by data (0.1-1 eV). For some regions of the MSSM-seesaw parameter space, the corrections to Mh are substantially larger than the anticipated Large Hadron Collider precision.Comment: Latex, 50 pages, 15 figures, 6 tables. Discussion improved. Comments and some new approximate formulae have been added. Published version on JHE
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