36,748 research outputs found

    The traveling-wave V-antenna

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    Combination resonant V-antenna and traveling-wave dipole antenn

    Design of recursive digital filters having specified phase and magnitude characteristics

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    A method for a computer-aided design of a class of optimum filters, having specifications in the frequency domain of both magnitude and phase, is described. The method, an extension to the work of Steiglitz, uses the Fletcher-Powell algorithm to minimize a weighted squared magnitude and phase criterion. Results using the algorithm for the design of filters having specified phase as well as specified magnitude and phase compromise are presented

    Master/slave manipulator system

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    System capabilities are equivalent to mobility, dexterity, and strength of human arm. Arrangement of torque motor, harmonic drive, and potentiometer combination allows all power and control leads to pass through center of slave with position-transducer arrangement of master, and "stovepipe joint" is incorporated for manipulator applications

    Analysis of distortion data from TF30-P-3 mixed compression inlet test

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    A program was conducted to reduce and analyze inlet and engine data obtained during testing of a TF30-P-3 engine operating behind a mixed compression inlet. Previously developed distortion analysis techniques were applied to the data to assist in the development of a new distortion methodology. Instantaneous distortion techniques were refined as part of the distortion methodology development. A technique for estimating maximum levels of instantaneous distortion from steady state and average turbulence data was also developed as part of the program

    Complementary Resources and the Exploitation of Technological Innovations

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    Technological innovation often results when the resources of a small firm are combined with those of a large one. This is because small and large firms characteristically possess complementary resources whose combination can facilitate innovation success. The possession of complementary innovation-producing resources by small and large firms helps explain patterns of interaction among firms in dynamic, technology-based industries. Propositions are developed that outline how typical resources of small and large firms can be used to explain industry-level phenomena surrounding technological change

    An improved analytical model of the separation region on boattail nozzles at subsonic speeds

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    A practical engineering calculation was developed to model the viscous effects of a separated, reverse flow region on afterbody pressures and drag. This viscous calculation was iteratively coupled with an inviscid flow calculation by means of an aerodynamic interface. A standard boundary layer displacement thickness was used to modify the afterbody shape where the flow was attached. A discriminating streamline calculation was developed to account for displacement effects of the reverse flow in separated regions with and without a flowing jet. The viscous flow calculation was coupled with a potential flow calculation. The analysis accurately predicted afterbody pressures and drag with variations in Reynolds number, Mach number, and afterbody shape

    Orbitofrontal epilepsy: Electroclinical analysis of surgical cases and literature review

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    Clinical and electrographic data were reviewed on 2 of our patients with orbitofrontal epilepsy who were seizure free at 5-year follow-up, and on 2 similar patients from the literature. One of our patients was lesional, and the other was nonlesional. Interictal EEG discharges were lateralized to the side of invasively recorded orbitofrontal seizures in the nonlesional case. In this case, no clinical manifestations occurred until the orbitofrontal discharge had spread to the opposite orbitofrontal and both mesial temporal areas. Unresponsiveness or arrest of activity were the initial manifestations of complex partial seizures in both cases. The 2 cases from the literature with long-term seizure-free follow-up had little impairment of awareness and displayed vigorous motor automatisms. Interictal epileptiform activity was bifrontally synchronous in 1 case. Ipsilateral frontotemporal discharges were seen in both. Invasive ictal epileptiform activity appeared maximal in the ipsilateral orbitofrontal region in both patients. No consistent electrographic or clinical pattern characterized these 4 cases. Seizures of orbitofrontal origin may be characterized by either unresponsiveness associated with oroalimentary automatisms or limited alteration of awareness and associated with vigorous motor automatisms. Invasive monitoring of the orbitofrontal cortex should be considered in nonlesional cases with complex partial seizures that show nonlocalizing ictal patterns and interictal frontal or frontotemporal epileptiform discharges. Copyright (C) 2004 S. Karger AG, Basel
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