399 research outputs found

    Real-Time Quantitative Bronchoscopy

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    The determination of motion within a sequence of images remains one of the fundamental problems in computer vision after more than 30 years of research. Despite this work, there have been relatively few applications of these techniques to practical problems outside the fields of robotics and video encoding. In this paper, we present the continuing work to apply optical flow and egomotion recovery to the problem of measuring and navigating through the airway using a bronchoscope during a standard procedure, without the need for any additional data, localization systems or other external components. The current implementation uses a number of techniques to provide a range of numerical measurements and estimations to physicians in real time, using standard computer hardware

    Strategic Facilities Planning: A Focus On Health Care

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    Turbulent market conditions have forced the health care sector to re-examine its business and operational practices.  Health care has become increasingly complex as decisions and planning are reframed in light of the current lagging economy, an increased demand for services, new global competition, and impending legislation reform.  The stress is felt most keenly within the nation’s hospitals and consortia of health care facilities.  Facility planning decisions are no exception.  Hospital administrators are abandoning the once commonplace rules governing aging infrastructure renovations.  Instead, administrators are basing decisions within their respective strategic context and are attempting to align buildings, services, personnel, and technology to an overall plan that looks at markets, operations, and finances as resources for competitive advantage.  This paper reviews the strategic facilities planning literature and applies those best practices which support this organizational alignment for health care.  An application in the mid-Atlantic demonstrates that hospital facilities, by design, need to support the current and future needs of health care delivery systems, while dated structures impede industry advances.  Health care infrastructure improvements must proactively address technological, regulatory, and financial changes facing the sector

    Evolution of the Quasar Luminosity Function Over 3 < z < 5 in the COSMOS Survey Field

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    We investigate the high-redshift quasar luminosity function (QLF) down to an apparent magnitude of I(AB) = 25 in the Cosmic Evolution Survey (COSMOS). Careful analysis of the extensive COSMOS photometry and imaging data allows us to identify and remove stellar and low-redshift contaminants, enabling a selection that is nearly complete for type-1 quasars at the redshifts of interest. We find 155 likely quasars at z > 3.1, 39 of which have prior spectroscopic confirmation. We present our sample in detail and use these confirmed and likely quasars to compute the rest-frame UV QLF in the redshift bins 3.1 < z < 3.5 and 3.5 < z < 5. The space density of faint quasars decreases by roughly a factor of four from z \sim 3.2 to z \sim 4, with faint-end slopes of {\beta} \sim -1.7 at both redshifts. The decline in space density of faint optical quasars at z > 3 is similar to what has been found for more luminous optical and X-ray quasars. We compare the rest-frame UV luminosity functions found here with the X-ray luminosity function at z > 3, and find that they evolve similarly between z \sim 3.2 and z \sim 4; however, the different normalizations imply that roughly 75% of X-ray bright active galactic nuclei (AGN) at z \sim 3 - 4 are optically obscured. This fraction is higher than found at lower redshift and may imply that the obscured, type-2 fraction continues to increase with redshift at least to z \sim 4. Finally, the implications of the results derived here for the contribution of quasars to cosmic reionization are discussed.Comment: Accepted for publication in ApJ. 17 pages, 14 figure

    Profiles of learning. The Basic Skills Testing Program in New South Wales 1989

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    The 1989 Basic Skills Testing Program in New South Wales provides the most comprehensive picture yet compiled of literacy and numeracy learning in Australian primary schools. In 1989, some 53,800 Year 6 students in NSW government schools were tested in five aspects of literacy and numeracy. Another 2,300 Year 3 students took part in a pilot study. This book discusses the writing of the tests, the analysis of results, and the reporting of results to parents, teachers and schools. The aim of the basic skills tests is to describe, in positive terms, the skills that students have mastered, to identify areas in which students have special strengths and weaknesses, and to provide guides to further learning. The picture that emerges from this study is of widespread success in learning. The results point to much good teaching and a fine start in learning for most primary students. But this generally optimistic picture is over shadowed by the performances of some students who have not yet mastered essential Year 6 skills. Part I of the book describes the skills typical of students performing at each of five skill levels in each of five areas of learning (Reading, Language, Number, Measurement, and Space) on the tests. Part II shows how different subgroups of students performed on the tests. Results on each aspect of literacy and numeracy are reported separately for girls and boys, students with non-English-speaking backgrounds, Aboriginal and Torres Strait Islander students, and several age groupings. Part III explains and gives examples of reports mailed to parents, more detailed reports given to teachers, and summary tables generated for each school. Part IV describes procedures used to develop BSTP tests and to analyze students\u27 results in preparation for reporting. Numerous test items are presented

    Predicting Future Space Near-IR Grism Surveys using the WFC3 Infrared Spectroscopic Parallels Survey

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    We present near-infrared emission line counts and luminosity functions from the HST WFC3 Infrared Spectroscopic Parallels (WISP) program for 29 fields (0.037 deg^2) observed using both the G102 and G141 grisms. Altogether we identify 1048 emission line galaxies with observed equivalent widths greater than 40 Angstroms, 467 of which have multiple detected emission lines. The WISP survey is sensitive to fainter flux levels (3-5x10^-17 ergs/s/cm^2) than the future space near-infrared grism missions aimed at baryonic acoustic oscillation cosmology (1-4x10^-16 ergs/s/cm^2), allowing us to probe the fainter emission line galaxies that the shallower future surveys may miss. Cumulative number counts of 0.7<z<1.5 galaxies reach 10,000 deg^-2 above an H-alpha flux of 2x10^-16 ergs/s/cm^2. H-alpha-emitting galaxies with comparable [OIII] flux are roughly 5 times less common than galaxies with just H-alpha emission at those flux levels. Galaxies with low H-alpha/[OIII] ratios are very rare at the brighter fluxes that future near-infrared grism surveys will probe; our survey finds no galaxies with H-alpha/[OIII] < 0.95 that have H-alpha flux greater than 3x10^-16 ergs/s/cm^2. Our H-alpha luminosity function contains a comparable number density of faint line emitters to that found by the NICMOS near-infrared grism surveys, but significantly fewer (factors of 3-4 less) high luminosity emitters. We also find that our high redshift (z=0.9-1.5) counts are in agreement with the high redshift (z=1.47) narrow band H-alpha survey of HiZELS (Sobral et al. 2013), while our lower redshift luminosity function (z=0.3-0.9) falls slightly below their z=0.84 result. The evolution in both the H-alpha luminosity function from z=0.3--1.5 and the [OIII] luminosity function from z=0.7-2.3 is almost entirely in the L* parameter, which steadily increases with redshift over those ranges.Comment: 18 pages, 14 figures, Accepted by Ap

    Discovery of Three Distant, Cold Brown Dwarfs in the WFC3 Infrared Spectroscopic Parallels Survey

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    We present the discovery of three late type (>T4) brown dwarfs, including a probable Y dwarf, in the WFC3 Infrared Spectroscopic Parallels (WISP) Survey. We use the G141 grism spectra to determine the spectral types of the dwarfs and derive distance estimates based on a comparison with nearby T dwarfs with known parallaxes. These are the most distant spectroscopically confirmed T/Y dwarfs, with the farthest at an estimated distance of ~400 pc. We compare the number of cold dwarfs found in the WISP survey with simulations of the brown dwarf mass function. The number found is generally consistent with an initial stellar mass function dN/dM \propto M^{-\alpha} with \alpha = 0.0--0.5, although the identification of a Y dwarf is somewhat surprising and may be indicative of either a flatter absolute magnitude/spectral type relation than previously reported or an upturn in the number of very late type brown dwarfs in the observed volume.Comment: Accepted for publication by ApJ Letters. 10 pages, 2 figure

    The Arecibo Legacy Fast ALFA Survey: VIII. HI Source Catalog of the Anti-Virgo Region at dec = +25 deg

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    We present a fourth catalog of HI sources from the Arecibo Legacy Fast ALFA (ALFALFA) Survey. We report 541 detections over 136 deg2, within the region of the sky having 22h < R.A. < 03h and 24 deg < Dec. < 26 deg . This complements a previous catalog in the region 26 deg < Dec. < 28 deg (Saintonge et al. 2008). We present here the detections falling into three classes: (a) extragalactic sources with S/N > 6.5, where the reliability of the catalog is better than 95%; (b) extragalactic sources 5.0 < S/N < 6.5 and a previously measured optical redshift that corroborates our detection; or (c) High Velocity Clouds (HVCs), or subcomponents of such clouds, in the periphery of the Milky Way. Of the 541 objects presented here, 90 are associated with High Velocity Clouds, while the remaining 451 are identified as extragalactic objects. Optical counterparts have been matched with all but one of the extragalactic objects.Comment: 26 pages, 5 figures, 1 table, accepted for publication in Astrophysical Journal Supplement Serie

    Fitting Age-Period-Cohort Models Using the Intrinsic Estimator: Assumptions and Misapplications

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    We thank Demography’s editorial office for the opportunity to respond to te Grotenhuis et al.’s commentary regarding the methods used and the results presented in our earlier paper (Masters et al. 2014). In this response, we briefly reply to three general themes raised in the commentary: (1) the presentation and discussion of APC results, (2) the fitting of full APC models to data for which a simpler model holds, and (3) the variation in the estimated age, period, and cohort coefficients produced by the intrinsic estimator (IE) (i.e., the “non-uniqueness property” of the IE, as referred to by Pelzer et al. (2015))
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