6,096 research outputs found

    Electron beam instrument for measuring electric fields Patent

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    Electron beam deflection devices for measuring electric field

    Performance improvement analysis for the Apollo unified S-band system Semiannual progress report

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    Performance improvement analysis for Apollo unified S band system, including computerized simulation techniques and phase lock loop studie

    Apollo experience report: Guidance and control systems. Lunar module stabilization and control system

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    A brief functional description of the Apollo lunar module stabilization and control subsystem is presented. Subsystem requirements definition, design, development, test results, and flight experiences are discussed. Detailed discussions are presented of problems encountered and the resulting corrective actions taken during the course of assembly-level testing, integrated vehicle checkout and test, and mission operations. Although the main experiences described are problem oriented, the subsystem has performed satisfactorily in flight

    Simulation and study of small numbers of random events

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    Random events were simulated by computer and subjected to various statistical methods to extract important parameters. Various forms of curve fitting were explored, such as least squares, least distance from a line, maximum likelihood. Problems considered were dead time, exponential decay, and spectrum extraction from cosmic ray data using binned data and data from individual events. Computer programs, mostly of an iterative nature, were developed to do these simulations and extractions and are partially listed as appendices. The mathematical basis for the compuer programs is given

    A Continuation Method for Nash Equilibria in Structured Games

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    Structured game representations have recently attracted interest as models for multi-agent artificial intelligence scenarios, with rational behavior most commonly characterized by Nash equilibria. This paper presents efficient, exact algorithms for computing Nash equilibria in structured game representations, including both graphical games and multi-agent influence diagrams (MAIDs). The algorithms are derived from a continuation method for normal-form and extensive-form games due to Govindan and Wilson; they follow a trajectory through a space of perturbed games and their equilibria, exploiting game structure through fast computation of the Jacobian of the payoff function. They are theoretically guaranteed to find at least one equilibrium of the game, and may find more. Our approach provides the first efficient algorithm for computing exact equilibria in graphical games with arbitrary topology, and the first algorithm to exploit fine-grained structural properties of MAIDs. Experimental results are presented demonstrating the effectiveness of the algorithms and comparing them to predecessors. The running time of the graphical game algorithm is similar to, and often better than, the running time of previous approximate algorithms. The algorithm for MAIDs can effectively solve games that are much larger than those solvable by previous methods

    Theoretical and lidar studies of the density response of the mesospheric sodium layer to gravity wave perturbations

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    The density response of atmospheric layers to gravity waves is developed in two forms, an exact solution and a perturbation series solution. The degree of nonlinearity in the layer density response is described by the series solution whereas the exact solution gives insight into the nature of the responses. Density perturbation in an atmospheric layer are shown to be substantially greater than the atmospheric density perturbation associated with the propagation of a gravity wave. Because of the density gradients present in atmospheric layers, interesting effects were observed such as a phase reversal in the linear layer response which occurs near the layer peak. Once the layer response is understood, the sodium layer can be used as a tracer of atmospheric wave motions. A two dimensional digital signal processing technique was developed. Both spatial and temporal filtering are utilized to enhance the resolution by decreasing shot noise by more han 10 dB. Many of the features associated with a layer density response to gravity waves were observed in high resolution density profiles of the mesospheric sodium layer. These include nonlinearities as well as the phase reversal in the linear layer response

    Frequency doubling conversion efficiencies for deep space optical communications

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    The theory of optical frequency doubling conversion efficiency is analyzed for the small signal input case along with the strong signal depleted input case. Angle phase matching and beam focus spot size are discussed and design trades are described which maximize conversion efficiency. Experimental conversion efficiencies from the literature, which are less than theoretical results at higher input intensities due to saturation, reconversion, and higher order processes, are applied to a case study of an optical communications link from Saturn. Double pass conversion efficiencies as high as 45 percent are expected. It is believed that even higher conversion efficiencies can be obtained using multipass conversion
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