5,425 research outputs found

    The 11 July 1988 Denver windshear encounters

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    On July 11, 1988, between 2207 and 2213 UTC (16:07 to 16:13 MDT), four successive United flights had inadvertent encounters with microburst windshear conditions while on final approach to Denver Stapleton Airport (DEN), each resulting in a missed approach, subsequent delay, and uneventful arrival. A fifth flight executed a missed approach without encountering the phenomena. There was no damage to aircraft and no passenger injuries were incurred. The term inadvertent is used within United Airlines' windshear training materials and the Federal Aviation Administration (FAA) Windshear Training Aid to connote an encounter with windshear after vigilance and cautionary practices fail to identify and afford complete avoidance of the hazardous area. No crew culpability is implied. A comprehensive investigation for scientific purposes in the study of windshear phenomenon is being conducted separately under the guidance of the FAA with involvement and cooperation from United, the National Transportation Safety Board (NTSB), National Center for Atmospheric Research (NCAR), Boeing, Douglas, NASA, and others

    Implementation of turbulence models into simulators

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    Simulation of turbulence as it relates to the flight training environment is discussed in general terms. Simulators that put random white noise into the system and simulators that put random motion into the equations of motion are discussed, as are simulators that incorporate pitch and roll moments into vertical turbulence. Wind shear models and simplified models of microburst phenomena are covered

    ORGANIC FOOD ADOPTION DECISIONS BY NEW MEXICO GROCERIES

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    Sales for organically grown foods, particularly organic fresh produce are increasing. This study focuses on the characteristics of grocery stores in New Mexico who sell or intend to sell organic foods. The results suggest most grocery stores do not carry organic foods because of the low availability and perceived consumer demand. However, stores that sell organic foods reported consumer demand prompted them to carry organic foods. The results can provide information for grocery stores to further understand problems and benefits associated with adopting organic foods.Agribusiness,

    Bayesian model selection for electromagnetic kaon production on the nucleon

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    We present the results of a Bayesian analysis of a Regge model to describe the background contribution for K+ Lambda and K+ Sigma0 photoproduction. The model is based on the exchange of K+(494) and K*+(892) trajectories in the t-channel. We utilise the Bayesian evidence Z to determine the best model variant for each channel. The Bayesian evidence integrals were calculated using the Nested Sampling algorithm. For different prior widths, we find decisive Bayesian evidence (\Delta ln Z ~ 24) for a K+ Lambda photoproduction Regge model with a positive vector coupling and a negative tensor coupling constant for the K*+(892) trajectory, and a rotating phase factor for both trajectories. Using the chi^2 minimisation method, one could not draw this conclusion from the same dataset. For the K+ Sigma0 photoproduction Regge model, on the other hand, the difference between the evidence integrals is insufficient to pinpoint one model variant.Comment: 13 pages, 4 figure

    They are Small Worlds After All: Revised Properties of Kepler M Dwarf Stars and their Planets

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    We classified the reddest (rJ>2.2r-J>2.2) stars observed by the NASA KeplerKepler mission into main sequence dwarf or evolved giant stars and determined the properties of 4216 M dwarfs based on a comparison of available photometry with that of nearby calibrator stars, as well as available proper motions and spectra. We revised the properties of candidate transiting planets using the stellar parameters, high-resolution imaging to identify companion stars, and, in the case of binaries, fitting light curves to identify the likely planet host. In 49 of 54 systems we validated the primary as the host star. We inferred the intrinsic distribution of M dwarf planets using the method of iterative Monte Carlo simulation. We compared several models of planet orbital geometry and clustering and found that one where planets are exponentially distributed and almost precisely coplanar best describes the distribution of multi-planet systems. We determined that KeplerKepler M dwarfs host an average of 2.2±0.32.2 \pm 0.3 planets with radii of 1-4RR_{\oplus} and orbital periods of 1.5-180 d. The radius distribution peaks at 1.2R\sim 1.2R_{\oplus} and is essentially zero at 4R4R_{\oplus}, although we identify three giant planet candidates other than the previously confirmed Kepler-45b. There is suggestive but not significant evidence that the radius distribution varies with orbital period. The distribution with logarithmic orbital period is flat except for a decline for orbits less than a few days. Twelve candidate planets, including two Jupiter-size objects, experience an irradiance below the threshold level for a runaway greenhouse on an Earth-like planet and are thus in a "habitable zone".Comment: MNRAS, in press. Tables 1, 3, and 4 are available in electronic form in the "anc" director

    Recent Developments in the Use of Interstate Water Compacts

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    Competency-based education for ministers in the Wesleyan church : best practices for educators

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    https://place.asburyseminary.edu/ecommonsatsdissertations/2506/thumbnail.jp

    GPU accelerated risk quantification

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    Factor Analysis of Information Risk (FAIR) is a standard model for quantitatively estimating cybersecurity risks and has been implemented as a sequential Monte Carlo simulation in the RiskLens and FAIR-U applications. Monte Carlo simulations employ random sampling techniques to model certain systems through the course of many iterations. Due to their sequential nature, FAIR simulations in these applications are limited in the number of iterations they can perform in a reasonable amount of time. One method that has been extensively used to speed up Monte Carlo simulations is to implement them to take advantage of the massive parallelization available when using modern Graphics Processing Units (GPUs). Such parallelized simulations have been shown to produce significant speedups, in some cases up to 3,000 times faster then the sequential versions. Due to the FAIR simulation\u27s need for many samples from various beta distributions, three methods of generating these samples via inverse transform sampling on the GPU are investigated. One method calculates the inverse incomplete beta function directly, and the other two methods approximate this function - trading accuracy for improved parallelism. This method is then utilized in a GPU accelerated implementation of the FAIR simulation from RiskLens and FAIR-U using NVIDIA\u27s CUDA technology
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