11,811 research outputs found
The biology and fishery of Atlantic sailfish Istiophorus platypterus from southeast Florida
(Document has 31 pages.
Public Broadcasting: A Medium in Search of Solutions
Simulation based methods used to estimate uncertainties in models have recently gained much interest. We study the bootstrap and how this method could be used in system identification related problems. The main contribution is a proposed algorithm to estimate the probability density function in case of undermodeling. We illustrate the performance of the bootstrap resampling method by simulation examples, which are in good agreement with Monte Carlo simulations
Astronaut tool development: An orbital replaceable unit-portable handhold
A tool to be used during astronaut Extra-Vehicular Activity (EVA) replacement of spent or defective electrical/electronic component boxes is described. The generation of requirements and design philosophies are detailed, as well as specifics relating to mechanical development, interface verifications, testing, and astronaut feedback. Findings are presented in the form of: (1) a design which is universally applicable to spacecraft component replacement, and (2) guidelines that the designer of orbital replacement units might incorporate to enhance spacecraft on-orbit maintainability and EVA mission safety
Ectoparasites and Other Arthropod Associates of Some Voles and Shrews From the Catskill Mountains of New York
Reported here from the Catskill Mountains of New York are 30 ectoparasites and other associates from 39 smoky shrews, Sorex fumeus, 17 from 11 masked shrews, Sorex cinereus, 11 from eight long-tailed shrews, Sorex dispar, and 31 from 44 rock voles, Microtus chrotorrhinus
Ectoparasites and Other Arthropod Associates of the Hairy-tailed Mole, \u3ci\u3eParascalops Breweri\u3c/i\u3e
A total of 33 taxa of ectoparasites and other associates was taken on seven individuals of the Hairy-tailed Mole, Parascalops breweri, from New York and New England. The most abundant form was the glycyphagid mite, Labidophorus nearcticus
Investigation of a moving-model technique for measuring ground effect
A ground-based testing technique is under development for the measurement of dynamic or time-dependent ground effects which may be present during aircraft approach and landing. The technique utilizes a model moving horizontally over an upwardly-inclined ground plane to simulate rate of descent. Results were obtained in the Langley Research Center (LaRC) Vortex Research Facility (VRF) for a generic 60 delta wing and for an F-18 configuration, both with and without thrust reversing, at forward speeds up to 100 ft/sec. These same models and support hardware were also tested in the LaRC 14 by 22 Foot Subsonic Tunnel at identical conditions (but without rate of descent) with and without a moving-belt ground plane to obtain data for comparison
An assessment of ground effects determined by static and dynamic testing techniques
A new testing technique was developed wherein the rate of descent can be included as a parameter in ground effects investigations. This technique simulates the rate of descent by horizontal motion of a model over an inclined ground board in the Langley Vortex Research Facility (VRF) During initial evaluations of the technique, dynamic ground effects data were obtained over the inclined ground board, steady state ground effects data were obtained over a flat portion of the ground board, and the results were compared to conventional static wind tunnel ground effect data both with and without a moving belt ground plane simulation. Initial testing and analysis led to the following conclusions: the moving belt ground plane had little effect on static ground effects for the configurations tested unless thrust reversers were employed; in general, rate-of-descent reduced ground effects to the point that for reversed thrust cases an expected loss of lift due to ground effects was eliminated at approach conditions; and, in general, the steady state results from the VRF matched static results obtained from the wind tunnel once the flow field stabilized over the flat portion of the ground board
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Anolis olssoni
Number of Pages: 5Integrative BiologyGeological Science
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