Digital compensation of the thrust vector control system Technical report, 28 May 1966 - 28 Sep. 1966
Sampled data control, quantization effects, and transfer function for Saturn 5 thrust vector control
Phillips, C. L.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Relationship of oxygen tension to viral disease Final report
Tissue culture development for isolation and quantization of lymphocytic choriomeningitis virus
Kirk, B. E.↗
The photoelectric effect without photons.
Photoelectric effect without photons, discussing classical field falling on quantized atomic electron
Lamb, W. E., Jr.↗
Non-Gaussian noise Progress report
Probability density functions for quantization noise, continuous wave interference, impulse noise, and atmospheric noise
Tuncer, K. F.↗
Log-linear companding - A digital companding technique.
Digital log-linear companding technique for nonuniform quantization of speech and image signals
Apple, G. G., Jr.↗
Neutron beta decay in a strong magnetic field
Neutron beta decay in strong quantizing magnetic field using Dirac wave function for electron, noting lifetime dependence on field strength
Fassio-Canuto, L.↗
On an extension of Mullin and Jury's method
Actuating signal at sampling instants determined in phase plane by Mullin-Jury method for sampled data feedback containing quantizer and zero order hold circuit
Klepl, M. J.↗
Nonuniqueness of the energy correction in application of the WKB approximation to radial problems
Radial energy eigenvalue problem conversion into one dimensional by infinite set of transformations, considering WKB quantization condition
Beckel, C. L.↗
Measurements of atomic order with the field-ion microscope
Near stoichiometric binary alloys atomic ordering parameters quantization by field ion micrography, using direct counting and optical transformation techniques
Hren, J. J.↗
Theory of radiation mechanisms of pulsars. I
Maserlike pulsar radiation mechanism using Coulomb bremsstrahlung near strong quantizing magnetic field
Canuto, V.↗
Hamiltonian cosmology
Polynomial Hamiltonian for type VIII and IX vacuum cosmologies, suggesting quantized versions involving fluctuations of 3-space signature and topology
Estabrook, F. B.↗
Oscillations in digital control systems
Signal quantization induced low amplitude oscillations in digital control systems, discussing relationship to digital controller programming form
Chenoweth, D. L.↗
Delta Modulation
An optimum adaptive delta modulator-demodulator configuration is derived. This device utilizes two past samples to obtain a step size which minimizes the mean square error for a Markov Gaussian source. The optimum system is compared using computer simulations with the linear delta modulator and an enhanced Abate delta modulator. In addition the performance is compared to the rate distortion bound for a Markov source. It is shown that the optimum delta modulator is neither quantization nor slope-overload limited. The results show that the output signal-to-noise ratio is independent of the input signal power and is subject only to the limitations of the hardware employed. In addition, voice was recorded using these systems. The demodulated voice indicates negligible degradation is caused by the optimum system and by the enhanced Abate system while the linear delta modulator suffers significant degradation at a sampling frequency of 56 kilobits/sec.
Schilling, D. L.↗
Pattern recognition systems and procedures
The objectives of the pattern recognition tasks are to develop (1) a man-machine interactive data processing system; and (2) procedures to determine effective features as a function of time for crops and soils. The signal analysis and dissemination equipment, SADE, is being developed as a man-machine interactive data processing system. SADE will provide imagery and multi-channel analog tape inputs for digitation and a color display of the data. SADE is an essential tool to aid in the investigation to determine useful features as a function of time for crops and soils. Four related studies are: (1) reliability of the multivariate Gaussian assumption; (2) usefulness of transforming features with regard to the classifier probability of error; (3) advantage of selecting quantizer parameters to minimize the classifier probability of error; and (4) advantage of using contextual data. The study of transformation of variables (features), especially those experimental studies which can be completed with the SADE system, will be done.
Nelson, G. D.↗
Thermal study of the Missouri River in North Dakota using infrared imagery
Studies of infrared imagery obtained from aircraft at 305- to 1,524-meter altitudes indicate the feasibility of monitoring thermal changes attributable to the operation of thermal electric plants and storage reservoirs, as well as natural phenomena such as tributary inflow and ground water seeps in large rivers. No identifiable sources of ground water inflow below the surface of the river could be found in the imagery. The thermal patterns from the generating plants and the major tributary inflow are readily apparent in imagery obtained from an altitude of 305 meters. Portions of the tape-recorded imagery were processed in a color-coded quantization to enhance the displays and to attach quantitative significance to the data. The study indicates a marked decrease in water temperature in the Missouri River prior to early fall and a moderate increase in temperature in late fall because of the Lake Sakakawea impoundment.
Crosby, O. A.↗
Handbook of operation and maintenance instructions for Model 5208A bit synchronizer unit
Electrical/mechanical characteristics, operation, theory of operation, parts list, and electrical diagrams for the model 5208A bit synchronizer unit are provided. The unit is capable of performing the functions of bit synchronization and signal conditioning on demodulated wave trains containing amplitude, frequency, and phase distortions, as well as additive noise. Operating frequencies in the 1 to 27 MHz bit rate range are accommodated through the use of discrete frequency plug-in subunits. The unit provides 0 and 180 degree clocks and either a single signal hard decision, or a three bit quantized soft decision data output.
Source record↗
Pattern recognition system and procedures
The ratio transformation technique is used to determine effective features as function of time in remote multiple sensing of crops and soils. The selection of quantizer parameters for a two-class recognition problem under the criteria of minimizing the probability of errors is also discussed.
Nelson, G. D.↗
Dynamic testing of a single-degree-of-freedom strapdown gyroscope
Test methods and results are presented for the equivalent average input rate of a single-degree-of-freedom gyroscope operated both open loop and with a ternary-logic pulse-torque-to-balance loop during multiaxis angular oscillation. For the open-loop tests, good agreement was obtained with theoretical results. Two-axis testing was performed for oscillations about the Input-Output axes, the Input-Spin axes, and the Spin-Output axes. These tests run in the torque-to-balance mode revealed significant departures from open-loop results in the induced drift rate. An analysis is developed explaining much of the closed-loop data presented. Test data for the gryoscope in a ternary torque-to-balance loop with constant input rates is presented. The tests demonstrate that the instrument rate linearity does not change with interrogation frequency from 3,600 to 14,400 Hz if the torque coil is tuned to offer a resistive load to the current switch. Analysis cited shows that gyroscope lag compensation eliminates multiple pulsing and other equivalent forms of degraded resolution in a wide variety of quantizing loops. This result is test verified for the ternary delta-modulator loop.
Lory, C. B.↗