1,651 research outputs found

    Tracking 3-D body motion for docking and robot control

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    An advanced method of tracking three-dimensional motion of bodies has been developed. This system has the potential to dynamically characterize machine and other structural motion, even in the presence of structural flexibility, thus facilitating closed loop structural motion control. The system's operation is based on the concept that the intersection of three planes defines a point. Three rotating planes of laser light, fixed and moving photovoltaic diode targets, and a pipe-lined architecture of analog and digital electronics are used to locate multiple targets whose number is only limited by available computer memory. Data collection rates are a function of the laser scan rotation speed and are currently selectable up to 480 Hz. The tested performance on a preliminary prototype designed for 0.1 in accuracy (for tracking human motion) at a 480 Hz data rate includes a worst case resolution of 0.8 mm (0.03 inches), a repeatability of plus or minus 0.635 mm (plus or minus 0.025 inches), and an absolute accuracy of plus or minus 2.0 mm (plus or minus 0.08 inches) within an eight cubic meter volume with all results applicable at the 95 percent level of confidence along each coordinate region. The full six degrees of freedom of a body can be computed by attaching three or more target detectors to the body of interest

    Small farmers start enjoying better deal

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    French version available in IDRC Digital Library: Sort des fermiers s'améliore peu à peuSpanish version available in IDRC Digital Library: Mejoran las condiciones de los pequeños agricultore

    Sort des fermiers s'améliore peu à peu

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    Version anglaise disponible dans la Bibliothèque numérique du CRDI: Small farmers start enjoying better dealVersion espagnole disponible dans la Bibliothèque numérique du CRDI: Mejoran las condiciones de los pequeños agricultore

    Protection of Nonimmune Volunteers against Rubella by Intravenous Administration of Normal Human Gamma Globulin

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    Standard gamma globulin, treated with pepsin and injected intravenously five days after infection, conferred passive protection against rubella on five volunteers. Intravenous injection of gamma globulin is superior to intramuscular injection, because the antibodies enter the bloodstream immediately, and an amount of antibody sufficient for protection can be given. Injection of standard gamma globulin is recommended when gamma globulin hyperimmune to rubella virus is unavailabl

    Mejoran las condiciones de los pequeños agricultores

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    Versión en inglés disponible en la Biblioteca Digital del IDRC: Small farmers start enjoying better dealVersión en francés disponible en la Biblioteca Digital del IDRC: Sort des fermiers s'améliore peu à pe

    Warum Kinderrechte ins Grundgesetz gehören

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    Ende November hat Bundesjustizministerin Christine Lamprecht (SPD) vorgeschlagen, das Grundgesetz zu ändern und darin ausdrücklich Kinderrechte zu verankern. Der Vorschlag befindet sich derzeit in der Ressortabstimmung. Auf dem Verfassungsblog hat sich Friederike Wapler kritisch mit diesem Entwurf auseinandergesetzt und am Ende empfohlen, statt einer schlechten Grundgesetzänderung lieber gar keine zu verabschieden. Ich hingegen halte eine solche Grundgesetzänderung für ebenso sinnvoll wie möglich

    Gutachten bezüglich der ausdrücklichen Aufnahme von Kinderrechten in das Grundgesetz nach Maßgabe der Grundprinzipien der UN-Kinderrechtskonvention

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    GUTACHTEN BEZÜGLICH DER AUSDRÜCKLICHEN AUFNAHME VON KINDERRECHTEN IN DAS GRUNDGESETZ NACH MASSGABE DER GRUNDPRINZIPIEN DER UN-KINDERRECHTSKONVENTION Gutachten bezüglich der ausdrücklichen Aufnahme von Kinderrechten in das Grundgesetz nach Maßgabe der Grundprinzipien der UN-Kinderrechtskonvention / Hofmann, Rainer (Rights reserved) ( -

    What’s in a (pseudo)name?: Ethical conundrums for the principles of anonymisation in social media research

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    Scholars from wide-ranging disciplines are turning to social media platforms as research sites, and as platforms expand their communicative possibilities, they create more spaces for users to enact a multitude of identities. Most platforms allow users to have ‘pseudonymous’ identities; that is, they can engage in practices intended to facilitate nonidentifiable content. But pseudonymity presents a series of unique challenges to the principles of anonymisation in qualitative research. This article explores the slippery nature of dealing with pseudonymous social media users’ personally identifiable data during research, framed around my responses to four questions I was asked when I applied for ethical approval to conduct research with pseudonymous fan communities on social media. The four questions concern: (Q1) changing notions of ‘public’ and ‘private’ forms of data; (Q2) identifying underage and therefore vulnerable participants online; (Q3) changes to the processes of obtaining informed consent from social media users; and (Q4) the risks social media research might bring to those conducting it. This article concludes by calling for qualitative researchers and Ethics Review Boards (ERBs) to engage with institutional ethics review across the duration of a project, or at the very least to advocate for ongoing consent as research progresses, especially for (but certainly not limited to) research involving pseudonymous social media users. The article aims to be useful to other researchers facing similar dilemmas. Indeed, given the popularity of pseudonymity on social media and the growing penetration of platforms across global demographics, a need for ethical discussions of this kind is surely set to increase

    Ferromagnetic Kondo-Lattice Model

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    We present a many-body approach to the electronic and magnetic properties of the (multiband) Kondo-lattice model with ferromagnetic interband exchange. The coupling between itinerant conduction electrons and localized magnetic moments leads, on the one hand, to a distinct temperature-dependence of the electronic quasiparticle spectrum and, on the other hand, to magnetic properties, as e.~g.the Curie temperature T_C or the magnon dispersion, which are strongly influenced by the band electron selfenergy and therewith in particular by the carrier density. We present results for the single-band Kondo-lattice model in terms of quasiparticle densities of states and quasiparticle band structures and demonstrate the density-dependence of the self-consistently derived Curie temperature. The transition from weak-coupling (RKKY) to strong-coupling (double exchange) behaviour is worked out. The multiband model is combined with a tight-binding-LMTO bandstructure calculation to describe real magnetic materials. As an example we present results for the archetypal ferromagnetic local-moment systems EuO and EuS. The proposed method avoids the double counting of relevant interactions and takes into account the correct symmetry of atomic orbitals.Comment: 15 pages, 10 figure
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