4,036 research outputs found

    Results of Skylab experiment T00-2, manual navigation sightings

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    An analysis of navigation data collected using a hand-held space sextant on the second and third manned Skylab missions was presented. From performance data and astronaut comments it was determined that: (1) the space sextant, the sighting station, and the sighting techniques require modification; (2) the sighting window must be of good optical quality; (3) astronaut performance was stable over long mission time; and (4) sightings made with a hand-held sextant were accurate and precise enough for reliable interplanetary manual navigation

    The background for Skylab experiment T-002, manual navigation sightings

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    The background of the NASA-DOD manual navigation experiment (T002) on Skylab A is reviewed with emphasis on NASA's development of an error model for sextant measurements in midcourse navigation and on USAF's development of a low earth orbit manual navigation scheme. Instruments briefly described are a space sextant and space stadimeter, both of which are used by USAF in orbit navigation, the sextant by NASA in midcourse sightings. The rationale, data requirements, and data reduction procedures are discussed in terms of the goals of the agencies

    Effects of magnification and visual accommodation on aimpoint estimation in simulated landings with real and virtual image displays

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    Twenty professional pilots observed a computer-generated airport scene during simulated autopilot-coupled night landing approaches and at two points (20 sec and 10 sec before touchdown) judged whether the airplane would undershoot or overshoot the aimpoint. Visual accommodation was continuously measured using an automatic infrared optometer. Experimental variables included approach slope angle, display magnification, visual focus demand (using ophthalmic lenses), and presentation of the display as either a real (direct view) or a virtual (collimated) image. Aimpoint judgments shifted predictably with actual approach slope and display magnification. Both pilot judgments and measured accommodation interacted with focus demand with real-image displays but not with virtual-image displays. With either type of display, measured accommodation lagged far behind focus demand and was reliably less responsive to the virtual images. Pilot judgments shifted dramatically from an overwhelming perceived-overshoot bias 20 sec before touchdown to a reliable undershoot bias 10 sec later

    Sextant sighting performance in measuring the angle between a stationary simulated star and a stationary blinking light

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    Sextant sighting performance in measuring angle between stationary simulated star and stationary blinking ligh

    Estimating the Value Added Product Life Cycle

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    This research analyzes factors affecting product and profit life-cycles for new value added products. The methodology used shows how sales and profits evolve and how exogenous factors affecting sales and profits. Results indicate that producers can increase the level of sales and profits over time through initial marketing efforts.Marketing,

    HOW MUCH VALUE IS THERE IN A PRODUCER BRANDED BRED HEIFER PROGRAM?

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    Agricultural producers are pursuing many methods by which to add value. Typically, some type of change in commodity form is used to add value. However, there exist methods by which added value occurs through intensive management practices, particularly in seedstock production. We investigated the brand premium to a producer-owned quality-based bred heifer program. Results indicated that producers garner in access of a $100/head premium, while potentially reducing future search/advertising costs through building brand loyalty.Livestock Production/Industries,

    Branched chain 2-oxo-acid dehydrogenase complex of rat liver

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    Numeración errónea en el original

    The use of total simulator training in transitioning air-carrier pilots: A field evaluation

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    A field study was conducted in which the performance of air carrier transitioning pilots who had landing training in a landing maneuver approved simulator was compared with the performance of pilots who had landing training in the aircraft. Forty-eight trainees transitioning to the B-727 aircraft and eighty-seven trainees transitioning to the DC-10 were included in the study. The study results in terms of both objectively measured performance indicants and observer and check-pilot ratings did not demonstrate a clear distinction between the two training groups. The results suggest that, for these highly skilled transitioning pilots, a separate training module in the aircraft may be of dubious value
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