13,171 research outputs found

    The Information of Spam

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    This paper explores the value of information contained in spam tweets as it pertains to prediction accuracy. As a case study, tweets discussing Bitcoin were collected and used to predict the rise and fall of Bitcoin value. Precision of prediction both with and without spam tweets, as identified by a naive Bayesian spam filter, were measured. Results showed a minor increase in accuracy when spam tweets were included, indicating that spam messages likely contain information valuable for prediction of market fluctuations

    Control for nuclear thermionic power source

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    A control for a power source which includes nuclear fuel interspersed with thermionic converters, is described. A power regulator maintains a substantially constant output voltage to a variable load, and a control circuit drives a neutron flux regulator in accordance with the current supplied to the power regulator and the neutron flux density in the region of the converters. The control circuit generates a control signal which is the difference between the neutron flux density and a linear function of the current, and drives the neutron regulator in a direction to decrease or increase the neutron flux according to the polarity of the control signal

    Stability and control characteristics of an air-breathing missile configuration having a forward located inlet

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    An investigation was made to determine the aerodynamic characteristics of an airbreathing missile configuration having a forward located inlet. Control was provided by cruciform tail surfaces. Aerodynamic data were obtained for the body-tail configuration alone and with planar or cruciform wings. At Mach numbers from 2.86 to 4.63, the model had internal flow. At Mach numbers from 1.70 to 2.86, the internal duct was closed, and an inlet fairing was installed to simulate boost conditions

    Determination of elevated-temperature fatigue data on refractory alloys in ultra- high vacuum fourth quarterly report, 1 apr. - 1 jul. 1965

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    High temperature fatigue data on refractory alloys in ultrahigh vacuum - tests on titanium- zirconium-molybdenu

    Generation of long time creep data of refrac- tory alloys at elevated temperatures seventh quarterly report, 26 dec. 1964 - 26 mar. 1965

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    Ultrahigh vacuum creep data for tungsten, tungsten-25 per cent rhenium, TZM and TZC MOLYBDENUM alloys and AS-30 niobium allo

    Generation of long time creep data of refractory alloys at elevated temperatures fifth quarterly report, 26 jun. - 26 sep. 1964

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    Creep testing data and machine reliability for high-temperature long-time tests on niobium, tungsten, and rhenium alloy

    Determination of elevated-temperature fatigue data on refractory alloys in ultra-high vacuum Fifth quarterly report, 1 Jul. - 1 Oct. 1965

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    Elevated-temperature fatigue data on notched and smooth specimens of refractory alloys in ultrahigh vacuum environment

    Computer program to determine pressure distributions and forces on blunt bodies of revolution

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    Program was written to include integration of surface pressure in order to obtain axial-force, normal-force, and pitching-moment coefficients. Program was written in CDC FORTRAN for the CDC-6600 computer system

    Generation of long time creep data of refractory alloys at elevated temperatures Eleventh quarterly report, 26 Dec. 1965 - 26 Mar. 1966

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    Creep tests of arc-cast and vapor deposited tungsten, molybdenum alloys, niobium, and tantalum base alloys for use in advanced power system

    Generation of long time creep data on refractory alloys at elevated temperatures eighth quarterly report

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    Creep resistance of refractory alloys at elevated temperatures under ultrahigh vacuum condition
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