10,344 research outputs found

    Human Engineering in Columbus

    Get PDF

    A Radio Determination of the Time of the New Moon

    Full text link
    The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative to the Sun and consequently gives us the ability to detect the Moon much closer to the Sun than is the case of visual observation. We first compare the relative brightness of the Moon and Sun over a range of possible frequencies and find the range 5--100\,GHz to be suitable. The next consideration is the atmospheric absorption/emission due to water vapour and oxygen as a function of frequency. This is particularly important since the relevant observations are near the horizon. We show that a frequency of 10\sim 10 GHz is optimal for this programme. We have designed and constructed a telescope with a FWHM resolution of 0 ⁣ ⁣^\circ{}\!\!.6 and low sidelobes to demonstrate the potential of this approach. At the time of the 21 May 2012 New Moon the Sun/Moon brightness temperature ratio was 72.7±2.272.7 \pm 2.2 in agreement with predictions from the literature when combined with the observed sunspot numbers for the day. The Moon would have been readily detectable at 2\sim 2^{\circ} from the Sun. Our observations at 16\,hr\,36\,min UT indicated that the Moon would have been at closest approach to the Sun 16\,hr\,25\,min earlier; this was the annular solar eclipse of 00\,hr\,00\,min\,UT on 21 May 2012.Comment: 11 pages, 15 figures, accepted for publication in MNRA

    In the Beginning... A Legacy of Computing at Marshall University

    Get PDF
    This book provides a brief history of the early computing technology at Marshall University, Huntington, W.Va., in the forty years: 1959-1999. This was before the move to Intel and Windows based servers. After installation of an IBM Accounting Machine in 1959, which arguably does not fit the modern definition of a computer, the first true computer arrived in 1963 and was installed in a room below the Registrar’s office. For the next twenty years several departments ordered their own midrange standalone systems to fit their individual departmental requirements. These represented different platforms from different vendors, and were not connected to each other. At the same time, the Marshall Computer Center developed an interconnected, multi-processor environment. With the software problems of year 2000, and the I/T move to the new Drinko Library, several systems were scrapped. New systems were installed on the pc server platforms. This book includes images of the various systems, several comments from users, and hardware and software descriptions

    Personality factors in flight operations. Volume 1: Leader characteristics and crew performance in a full-mission air transport simulation

    Get PDF
    Crew effectiveness is a joint product of the piloting skills, attitudes, and personality characteristics of team members. As obvious as this point might seem, both traditional approaches to optimizing crew performance and more recent training development highlighting crew coordination have emphasized only the skill and attitudinal dimensions. This volume is the first in a series of papers on this simulation. A subsequent volume will focus on patterns of communication within crews. The results of a full-mission simulation research study assessing the impact of individual personality on crew performance is reported. Using a selection algorithm described in previous research, captains were classified as fitting one of three profiles along a battery of personality assessment scales. The performances of 23 crews led by captains fitting each profile were contrasted over a one-and-one-half-day simulated trip. Crews led by captains fitting a positive Instrumental-Expressive profile (high achievement motivation and interpersonal skill) were consistently effective and made fewer errors. Crews led by captains fitting a Negative Expressive profile (below average achievement motivation, negative expressive style, such as complaining) were consistently less effective and made more errors. Crews led by captains fitting a Negative Instrumental profile (high levels of competitiveness, verbal aggressiveness, and impatience and irritability) were less effective on the first day but equal to the best on the second day. These results underscore the importance of stable personality variables as predictors of team coordination and performance

    CBI limits on 31 GHz excess emission in southern HII regions

    Get PDF
    We have mapped four regions of the southern Galactic plane at 31 GHz with the Cosmic Background Imager. From the maps, we have extracted the flux densities for six of the brightest \hii regions in the southern sky and compared them with multi-frequency data from the literature. The fitted spectral index for each source was found to be close to the theoretical value expected for optically thin free-free emission, thus confirming that the majority of flux at 31 GHz is due to free-free emission from ionised gas with an electron temperature of 70008000\approx 7000-8000 K. We also found that, for all six sources, the 31 GHz flux density was slightly higher than the predicted value from data in the literature. This excess emission could be due to spinning dust or another emission mechanism. Comparisons with 100μ100 \mum data indicate an average dust emissivity of 3.3±1.7μ3.3\pm1.7 \muK (MJy/sr)1^{-1}, or a 95 per cent confidence limit of <6.1μ<6.1 \muK (MJy/sr)1^{-1}. This is lower than that found in diffuse clouds at high Galactic latitudes by a factor of 34\sim 3-4. The most significant detection (3.3σ3.3\sigma) was found in G284.30.3G284.3-0.3 (RCW49) and may account for up to 30\approx 30 per cent of the total flux density observed at 31 GHz. Here, the dust emissivity of the excess emission is 13.6±4.2μ13.6\pm4.2 \muK (MJy/sr)1^{-1} and is within the range observed at high Galactic latitudes. Low level polarised emission was observed in all six sources with polarisation fractions in the range 0.30.60.3-0.6 per cent. This is likely to be mainly due to instrumental leakage and is therefore upper an upper limit to the free-free polarisation. It corresponds to an upper limit of 1\sim1 per cent for the polarisation of anomalous emission.Comment: Accepted in MNRAS. 12 pages, 10 figures, 5 table
    corecore