22,315 research outputs found

    Control System Optimization for Saturn 5 Launch Vehicles Using Gradient Techniques Final Report

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    Control system optimization for Saturn 5 launch vehicles using gradient technique

    Differential equations for the cuspoid canonical integrals

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    Differential equations satisfied by the cuspoid canonical integrals I_n(a) are obtained for arbitrary values of n≥2, where n−1 is the codimension of the singularity and a=(ɑ_1,ɑ_2,...,ɑ_(n−1)). A set of linear coupled ordinary differential equations is derived for each step in the sequence I_n(0,0,...,0,0) →I_n(0,0,...,0,ɑ_(n−1)) →I_n(0,0,...,ɑ_(n−2),ɑ_(n−1)) →...→I_n(0,ɑ_2,...,ɑ_(n−2),ɑ_(n−1)) →I_n(ɑ_1,ɑ_2,...,ɑ_n−2,ɑ_(n−1)). The initial conditions for a given step are obtained from the solutions of the previous step. As examples of the formalism, the differential equations for n=2 (fold), n=3 (cusp), n=4 (swallowtail), and n=5 (butterfly) are given explicitly. In addition, iterative and algebraic methods are described for determining the parameters a that are required in the uniform asymptotic cuspoid approximation for oscillating integrals with many coalescing saddle points. The results in this paper unify and generalize previous researches on the properties of the cuspoid canonical integrals and their partial derivatives

    Academic Dishonesty: Recommendations for the Future of Higher Education

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    The culture of academic dishonesty has become a common practice among students across numerous college campuses. It is imperative to address the policies designed to clearly define plagiarism and academic integrity, as they are not universally understood. The authors explore how academic dishonesty and academic integrity are defined at varying institutions and compare and contrast how such policy violations are addressed by campus administrators. The authors propose recommendations for campus administrators and policymakers to redefine best practices for faculty and staff to instill a culture of academic integrity on college campuses

    A study for development of aerothermodynamic test model materials and fabrication technique

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    A literature survey, materials reformulation and tailoring, fabrication problems, and materials selection and evaluation for fabricating models to be used with the phase-change technique for obtaining quantitative aerodynamic heat transfer data are presented. The study resulted in the selection of two best materials, stycast 2762 FT, and an alumina ceramic. Characteristics of these materials and detailed fabrication methods are presented

    Bulge plus disc and S\'ersic decomposition catalogues for 16,908 galaxies in the SDSS Stripe 82 co-adds: A detailed study of the ugrizugriz structural measurements

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    Quantitative characterization of galaxy morphology is vital in enabling comparison of observations to predictions from galaxy formation theory. However, without significant overlap between the observational footprints of deep and shallow galaxy surveys, the extent to which structural measurements for large galaxy samples are robust to image quality (e.g., depth, spatial resolution) cannot be established. Deep images from the Sloan Digital Sky Survey (SDSS) Stripe 82 co-adds provide a unique solution to this problem - offering 1.61.81.6-1.8 magnitudes improvement in depth with respect to SDSS Legacy images. Having similar spatial resolution to Legacy, the co-adds make it possible to examine the sensitivity of parametric morphologies to depth alone. Using the Gim2D surface-brightness decomposition software, we provide public morphology catalogs for 16,908 galaxies in the Stripe 82 ugrizugriz co-adds. Our methods and selection are completely consistent with the Simard et al. (2011) and Mendel et al. (2014) photometric decompositions. We rigorously compare measurements in the deep and shallow images. We find no systematics in total magnitudes and sizes except for faint galaxies in the uu-band and the brightest galaxies in each band. However, characterization of bulge-to-total fractions is significantly improved in the deep images. Furthermore, statistics used to determine whether single-S\'ersic or two-component (e.g., bulge+disc) models are required become more bimodal in the deep images. Lastly, we show that asymmetries are enhanced in the deep images and that the enhancement is positively correlated with the asymmetries measured in Legacy images.Comment: 27 pages, 14 figures. MNRAS accepted. Our catalogs are available in TXT and SQL formats at http://orca.phys.uvic.ca/~cbottrel/share/Stripe82/Catalogs

    Exploring Deep-Sea Data

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    The Monterey Bay Aquarium Research Institute (MBARI) has collected and archived deep-sea video from remotely operated vehicle dives since 1988. The video archive contains footage and data on the biological, chemical, geological, and physical aspects of deep regions of the Pacific. MBARI developed a software system, the Video Annotation and Reference System, to create, store, and retrieve video annotations. The system is based on a hierarchical catalog of biological, geological, and technical terms that allows consistent and rapid classification of objects seen on video. Based on knowledge collected by the annotation process, MBARI staff developed a web-based Deep-Sea Guide to the organisms and geologic features recorded on remotely operated vehicle dives into the deep sea. The searchable guide provides information about biological taxonomy, geology, and habitats, and displays dynamic histograms and useful statistics derived from the video annotations

    Low altitude temperature and humidity profile data for application to aircraft noise propagation

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    A data search of the weather statistics from 11 widely dispersed geographical locations within the continental United States was conducted. The sites, located long both sea-coasts and in the interior, span the northern, southern, and middle latitudes. The weather statistics, retrieved from the records of these 11 sites, consist of two daily observations taken over a 10-year period. The data were sorted with respect to precipitation and surface winds and classified into temperature intervals of 5 C and relative humidity intervals of 10 percent for the lower 1400 meters of the atmosphere. These data were assembled in a statistical format and further classified into altitude increments of 200 meters. The data are presented as sets of tables for each site by season of the year and include both daily observations

    The application of optimal control technqiues to advanced manned missions, volume 1

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    Two problems are presented in the area of optimal control and its application to the design of attitude control systems for advanced complex aerospace vehicles. The problems discussed are specification of performance criteria in terms of structural load minimization and/or maximum orbital payload injection requirements of the controlled vehicle; and formulation and solution of the optimization problem such that practical control systems are obtained
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