111,443 research outputs found

    Fast redshift clustering with the Baire (ultra) metric

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    The Baire metric induces an ultrametric on a dataset and is of linear computational complexity, contrasted with the standard quadratic time agglomerative hierarchical clustering algorithm. We apply the Baire distance to spectrometric and photometric redshifts from the Sloan Digital Sky Survey using, in this work, about half a million astronomical objects. We want to know how well the (more cos\ tly to determine) spectrometric redshifts can predict the (more easily obtained) photometric redshifts, i.e. we seek to regress the spectrometric on the photometric redshifts, and we develop a clusterwise nearest neighbor regression procedure for this.Comment: 14 pages, 6 figure

    CO on Ru(001): Formation and dissolution of islands of CO at low coverages

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    The present paper deals with the benefits and difficulties of using ion scattering spectroscopy as a spectrometric technique

    The determination of major and some minor constituents in lead zirconate-titanate compositions by x-ray fluorescence and atomic absorption spectrometry

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    An accurate X-ray fluorescence spectrometric method is described for the determination of lead, zirconium and titanium in lead zirconate-titanate ceramics. Careful matching of samples and standards by a borax fusion method resulted in a relative standard deviation of about 0.2% for the major constituents. The determination, after separation, of the unreacted oxide of lead by atomic absorption spectrometry, and of the unreacted oxides of zirconium and titanium by X-ray fluorescence spectrometry is also described. An X-ray fluorescence spectrometric method is proposed for the determination of dope elements (K, La, Sm, Yb) with internal standards (Ca, Ce, Cr, Ni respectively). The magnesium dope is determined by atomic-absorption spectrometry with standard addition

    Estimate of the possibility of conducting mass spectrometric measurements of the matter of lunar surface

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    Electron beams studied for use in lunar soil spectrometric analysi

    Mass-spectrometric investigation of reaction of oxygen atoms with methane

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    Mass spectrometric investigation of oxygen atoms reacting with methan

    Ultraviolet dayglow and stellar brightness measurement from the X-15 aircraft

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    Airborne stellar photometry and spectrometric determination of day sky brightnes

    Earth-based lunar atmosphere investigation Final report

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    Instrumentation and results of earth-based spectrometric identification of lunar atmospheric constituents in visible regio

    Mass spectrometric determination of the dissociation energies of titanium dicarbide and titanium tetracarbide

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    Mass spectrometric determination of dissociation energies of titanium dicarbide and titanium tetracarbid
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