2,961 research outputs found

    Solutions of differential equations with regular coefficients by the methods of Richmond and Runge-Kutta

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    Numerical solutions of the differential equation which describe the electric field within an inhomogeneous layer of permittivity, upon which a perpendicularly-polarized plane wave is incident, are considered. Richmond's method and the Runge-Kutta method are compared for linear and exponential profiles of permittivities. These two approximate solutions are also compared with the exact solutions

    My right to learn

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    If books and other media are thought to be connected with terrorism, yet the government does not release a list of such material or inform individuals that they are under suspicion, can students truly feel free to learn, even at a university? Is a free flow of ideas truly possible in a place where only certain ideas are allowed? Is freedom of speech even relevant in a society where expression of certain thoughts or viewpoints is prohibited

    Modified Hilbert transform pair and Kramers-Kronig relations for complex permittivities

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    Modified versions of the Hilbert transform pair and the Kramers-Kronig relations are derived for the complex permittivity of a plasma/dielectric medium which is singular at the frequency of the applied electric field equal to 0. Such a complex permittivity exists when the plasma/dielectric model allows a loss term but no restoring term. Permittivity, in which both loss and restoring terms are included, is shown to satisfy the standard Hilbert transform pair and, thus, the Kramers-Kronig relations

    Angular power spectrums and their relationship to autocorrelation functions of aperture antennas

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    Normalized angular power spectrum representations have been derived for linear and circular aperture antennas in terms of their autocorrelation functions. Examples of their use are given

    Paving the Way: The Influence of Early Research and Development Programs on Apollo, Saturn, and Legacy System Development

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    As we celebrate the 50th anniversary of the first successful human landings on the surface of the Moon in 1969, it is insightful to review the many historic accomplishments that contributed to this astounding human achievement. While the Apollo Program officially began following the charge by United States President John F. Kennedy in 1961, much of the foundation for Apollo was already underway with early research and development that began as early as the close of the second World War. Innovations and key decisions prior to the formal initiation of the Apollo Program, and even prior to the formation of the National Aeronautics and Space Administration (NASA), enabled the relatively rapid development of the Saturn V rocket, the Apollo capsule, and the Lunar Lander systems needed to achieve the goal of landing humans on the Moon and returning them safely to Earth by the close of the 1960s

    Apollo experience report: Onboard navigational and alignment software

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    The onboard navigational and alignment routines used during the nonthrusting phases of an Apollo mission are discussed as to their limitations, and alternate approaches that have more desirable capabilities are presented. A more efficient procedure for solving Kepler's equation, which is used in the calculation of Kepler's problem and Lambert's problem is included, and a sixth-order predictor scheme with a Runge-Kutta starter is recommended for numerical integration. The extension of the rendezvous navigation state to include angle biases and the use of a fixed coordinate system is also evaluated

    To Build A Better Textbook: Developing a Literature Curriculum for Today’s Christian Schooling

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    This thesis explores the educational philosophy and the creative process behind the creation of a new textbook and curriculum. The goal of this new textbook and curriculum is to help persuade high school students to view literature as an avenue of life-long learning. The plan to develop this textbook and curriculum is built on five objectives: a recognition of the need for holistic education, the implementation of differentiated teaching methods, the cultivation of student interest, the reflection of diversity within classrooms, and the integration of modern technology. This plan will be proposed in the creation of a textbook for use in world literature classes in Christian schools as well as in homeschools. The curriculum will tap into new and old learning technologies and include links to notes, flashcards, presentations, study games, and informational videos in addition to the newest learning apps. This inclusion of various learning tools through an intentional integration of technology will make the textbook and curriculum marketable on a large scale

    NASA Affordable Vehicle Avionics (AVA): Common Modular Avionics System for Nano-Launchers Offering Affordable Access to Space

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    Small satellites are becoming ever more capable of performing valuable missions for both government and commercial customers. However, currently these satellites can only be launched affordably as secondary payloads. This makes it difficult for the small satellite mission to launch when needed, to the desired orbit, and with acceptable risk. NASA Ames Research Center has developed and tested a prototype low-cost avionics package for space launch vehicles that provides complete GNC functionality in a package smaller than a tissue box with a mass less than 0.84 kg. AVA takes advantage of commercially available, low-cost, mass-produced, miniaturized sensors, filtering their more noisy inertial data with realtime GPS data. The goal of the Advanced Vehicle Avionics project is to produce and flight-verify a common suite of avionics and software that deliver affordable, capable GNC and telemetry avionics with application to multiple nano-launch vehicles at 1 the cost of current state-of-the-art avionics
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