2,198 research outputs found

    Educating Engineers To Manage Technology: An International Comparison

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    Two countries, the United States and Australia, are compared in terms of: (1) the historical growth of their engineering professions; (2) the structure of their engineering professional organizations; (3) the prevalence of engineers in management positions; and (4 the education of their engineers for management responsibilities

    An analysis of pilot error-related aircraft accidents

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    A multidisciplinary team approach to pilot error-related U.S. air carrier jet aircraft accident investigation records successfully reclaimed hidden human error information not shown in statistical studies. New analytic techniques were developed and applied to the data to discover and identify multiple elements of commonality and shared characteristics within this group of accidents. Three techniques of analysis were used: Critical element analysis, which demonstrated the importance of a subjective qualitative approach to raw accident data and surfaced information heretofore unavailable. Cluster analysis, which was an exploratory research tool that will lead to increased understanding and improved organization of facts, the discovery of new meaning in large data sets, and the generation of explanatory hypotheses. Pattern recognition, by which accidents can be categorized by pattern conformity after critical element identification by cluster analysis

    Buffalo National River Ecosystems - Part II

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    The priorities were established for the Buffalo National River Ecosystem Studies through meetings and correspondence with Mr. Roland Wauer and other personnel of the Office of Natural Sciences, Southwest Region of the National Park Service. These priorities were set forth in the appendix of contract no. CX 700050443 dated May 21, 1975

    Breakdown of Angular Momentum Selection Rules in High Pressure Optical Pumping Experiments

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    We present measurements, using two complementary methods, of the breakdown of atomic angular momentum selection rules in He-broadened Rb vapor. Atomic dark states are rendered weakly absorbing due to fine-structure mixing during Rb-He collisions. The effect substantially increases the photon demand for optical pumping of dense vapors

    Astrometric-spectroscopic determination of the absolute masses of the HgMn binary star Phi Herculis

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    The Mercury-Manganese star Phi Her is a well known spectroscopic binary that has been the subject of a recent study by Zavala et al. (2006), in which they resolved the companion using long-baseline interferometry. The total mass of the binary is now fairly well established, but the combination of the spectroscopy with the astrometry has not resulted in individual masses consistent with the spectral types of the components. The motion of the center of light of Phi Her was clearly detected by the Hipparcos satellite. Here we make use of the Hipparcos intermediate data (`abscissa residuals') and show that by combining them in an optimal fashion with the interferometry the individual masses can be obtained reliably using only astrometry. We re-examine and then incorporate existing radial-velocity measurements into the orbital solution, obtaining improved masses of 3.05 +/- 0.24 M_Sun and 1.614 +/- 0.066 M_Sun that are consistent with the theoretical mass-luminosity relation from recent stellar evolution models. These mass determinations provide important information for the understanding of the nature of this peculiar class of stars.Comment: Total of 18 pages including figures and tables, in emulateapj format. To appear in The Astronomical Journal, June 2007 issu

    A psychometric evaluation of the interRAI Child and Youth Mental Health instruments (ChYMH) anxiety scale in children with and without developmental disabilities

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    Background: With 10 to 20% of Canadian children suffering with mental illness, the importance of early identification and accurate assessment systems is clear. Unfortunately, many do not receive the mental health treatment necessary and wait-times for assessment can span up to a year. In response, the interRAI suite of assessments were designed to comprehensively assess early signs of mental health impairments in children from birth to 18 years. Methods: This study assesses the psychometric properties of the Anxiety Scale and addresses the identification of anxiety within children diagnosed with intellectual and developmental disabilities (IDD); a commonly underrepresented sample in mental health psychometric studies. Data was collected from children aged 4-18 years in three different samples. Results: Results indicated reliable internal consistency and factor structure, as well as moderate-to-strong convergent validity. Conclusions: We conclude that the Anxiety Scale exhibits psychometric qualities which demonstrate its clinical utility for use within a child sample, as well as in children with IDD. The findings provide support to a larger body of research which show consistent psychometric rigour of the interRAI measures

    Final Report: Buffalo National River Ecosystems

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    The objective of this study was to sample the Buffalo River on a seasonal basis for a year, in order to determine whether any potential water quality problems existed

    Buffalo National River Ecosystem - Part III

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    Samples for water quality analyses and phycological studies were taken from the nine standard sampling locations on the Buffalo River nine times during the period from March 1976 through February 1977. The April-June 1976 samples represent nearly identical conditions throughout the spring period; therefore, emphasis was placed on taxonomic research. As the early January sample was considered sufficient~y reflective of stable winter conditions, the December and February periods were. used for detailed microscopic examination of the rich and diverse diatom flora that was found in the river this year. A total of 273 taxa of diatoms were identified from the 75 samples collected, including 123 new additions to the diatom flora of the Buffalo River. Details of this study, including the breakdown of many species into varieties, will be presented in a separate paper. A list of the new species found and a general discussion are included in this report

    Final Report Buffalo National River Ecosystems Part IV

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    Sampling point locations and analytical procedures remained unchanged from those outlined in previous Buffalo National River Ecosystem reports. The only significant change in analytical procedures was a reversion to the glass fiber filter method for collection and extraction of samples for chlorophyll analysis. This change was neeessitated by a need for filtering a larger volume to obtain enough chlorophyll for an accurate measurement. Samples were collected monthly from April 9 through December 30. No samples were taken in January or February due to the extremely uncertain traveling conditions caused by the frequent snows. Prior research indicates that the December 30 sample is sufficiently reflective of stable winter conditions to obviate the need for more winter samples (see previous reports)
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