13,171 research outputs found
The Information of Spam
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
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
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
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
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
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
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
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
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
Creep resistance of refractory alloys at elevated temperatures under ultrahigh vacuum condition
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