138 research outputs found

    Drei Thesen zur Kompetenzorientierung

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    Im Folgenden werde ich drei Thesen zur Kompetenzorientierung (eine affirmative, eine fundamental-kritische und eine kritischkonstruktive) vorstellen und ansatzweise begründen - u.a. anknüpfend an Erfahrungen mit dem 'Kompetenz-Portfolio für Freiwillige' des Ringes Österreichischer Bildungswerke (Exkurse I und II). These 1: Die Kompetenzorientierung ist plausibel und praktisch. These 2: Die Kompetenzorientierung ist idealistisch und harmonistisch. These 3: Die Kompetenzorientierung bedarf einer ethisch-politischen Erweiterung

    Borel Conjecture and Dual Borel Conjecture

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    We show that it is consistent that the Borel Conjecture and the dual Borel Conjecture hold simultaneously.Comment: 47 pages, revised version 2013 (some typos removed, some points elaborated. Dedication added.

    The metrology system of the VLTI instrument GRAVITY

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    The VLTI instrument GRAVITY combines the beams from four telescopes and provides phase-referenced imaging as well as precision-astrometry of order 10 microarcseconds by observing two celestial objects in dual-field mode. Their angular separation can be determined from their differential OPD (dOPD) when the internal dOPDs in the interferometer are known. Here, we present the general overview of the novel metrology system which performs these measurements. The metrology consists of a three-beam laser system and a homodyne detection scheme for three-beam interference using phase-shifting interferometry in combination with lock-in amplifiers. Via this approach the metrology system measures dOPDs on a nanometer-level.Comment: 9 pages, 5 figure

    Choroidal Haller's and Sattler's Layer Thickness Measurement Using 3-Dimensional 1060-nm Optical Coherence Tomography

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    Objectives: To examine the feasibility of automatically segmented choroidal vessels in three-dimensional (3D) 1060-nmOCT by testing repeatability in healthy and AMD eyes and by mapping Haller's and Sattler's layer thickness in healthy eyes Methods: Fifty-five eyes (from 45 healthy subjects and 10 with non-neovascular age-related macular degeneration (AMD) subjects) were imaged by 3D-1060-nmOCT over a 36°x36° field of view. Haller's and Sattler's layer were automatically segmented, mapped and averaged across the Early Treatment Diabetic Retinopathy Study grid. For ten AMD eyes and ten healthy eyes, imaging was repeated within the same session and on another day. Outcomes were the repeatability agreement of Haller's and Sattler's layer thicknesses in healthy and AMD eyes, the validation with ICGA and the statistical analysis of the effect of age and axial eye length (AL) on both healthy choroidalsublayers. Results: The coefficients of repeatability for Sattler's and Haller's layers were 35% and 21% in healthy eyes and 44% and 31% in AMD eyes, respectively. The mean±SD healthy central submacular field thickness for Sattler's and Haller's was 87±56 µm and 141±50 µm, respectively, with a significant relationship for AL (P<.001). Conclusions: Automated Sattler's and Haller's thickness segmentation generates rapid 3D measurements with a repeatability correspondingto reported manual segmentation. Sublayers in healthy eyes thinnedsignificantly with increasing AL. In the presence of the thinned Sattler's layer in AMD, careful measurement interpretation is needed. Automatic choroidal vascular layer mapping may help to explain if pathological choroidal thinning affects medium and large choroidal vasculature in addition to choriocapillaris loss.Macular Vision Research FoundationMedical University of ViennaEuropean Union (project FUN OCT (FP7 HEALTH, contract no. 201880))European Union (FAMOS (FP7 ICT 317744))European Union (FWF-NFN ‘Photoacoustic imaging in biology and Medicine’, Oesterreichische Nationalbank Jubilaumsfonds projekt (14294))National Institutes of Health (U.S.) (NIH R01-EY011289-27)Deutsche Forschungsgemeinschaft (DFG-GSC80-SAOT)Deutsche Forschungsgemeinschaft (DFG-GSC80-SAOT, DFG-HO-1791/11-1)Carl Zeiss Meditec, Inc.FEMTOLASERS (Firm)Christian Doppler Societ

    The GRAVITY instrument software / High-level software

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    GRAVITY is the four-beam, near- infrared, AO-assisted, fringe tracking, astrometric and imaging instrument for the Very Large Telescope Interferometer (VLTI). It is requiring the development of one of the most complex instrument software systems ever built for an ESO instrument. Apart from its many interfaces and interdependencies, one of the most challenging aspects is the overall performance and stability of this complex system. The three infrared detectors and the fast reflective memory network (RMN) recorder contribute a total data rate of up to 20 MiB/s accumulating to a maximum of 250 GiB of data per night. The detectors, the two instrument Local Control Units (LCUs) as well as the five LCUs running applications under TAC (Tools for Advanced Control) architecture, are interconnected with fast Ethernet, RMN fibers and dedicated fiber connections as well as signals for the time synchronization. Here we give a simplified overview of all subsystems of GRAVITY and their interfaces and discuss two examples of high-level applications during observations: the acquisition procedure and the gathering and merging of data to the final FITS file.Comment: 8 pages, 7 figures, published in Proc. SPIE 9146, Optical and Infrared Interferometry IV, 91462

    Diskussion über "Die deutsche Jugend" und "Jugendpflege, Jugendbewegung"

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    Diskussion über die beiden Vorträge: 1. Litt, Theodor: Die deutsche Jugend in der Gegenwart; 2. Becker, Howard: Jugendpflege und Jugendbewegung einst und heut
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