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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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Set of design curves eliminates work involved in designing linear phase filters by being normalized in such a way as to apply to low, band, and high-pass filters of any bandwidth. Similar curves for any number of poles are plotted by solving a system of simultaneous equations.
Low pass filter, bandpass filter, and design of input system for speech recognition computer
Linearly filtered angle modulated signals distortion and crosstalk analysis applied to filter input-output relation, noting satellite communication FM reception
Optimal linear filter derivation using Pontryagin maximum principle and gradient matrices for optimal filter coefficients
Limited memory optimal filter theory, output and standard filter divergence due to errors
Transmission measurement of neutrons by filter materials for low energy neutrons is important for the study of structure and dynamics of condensed matter. Since only thermal neutrons are useful for such experiments, filter materials that transmit thermal neutrons while attenuating fast neutrons and gamma rays are of considerable interest.
Range switching digital filter with three predetermined quantization levels decreases quantization deadband. Mathematical program form implements the transfer function of the filter.
Generalized digital filter is a special purpose computer. The term digital filter is an algorithm which accepts an input sequence of numbers and transforms it into an output number sequence. The organization of the computer, the logical design and synthesis, and experimentaion with the computer in two sampled data control systems is discussed.
Narrow band optical filter is electronically tunable over a large wavelength region. The filter utilizes collinear acousto-optic diffraction in an optically anisotropic media.
Blocking filter effects on long-wavelength rejection of ultraviolet bandpass filter
Limited memory optimal filter theory, output and standard filter divergence due to errors
Adaptive filtering to prevent divergence observed in application of Kalman filter to orbit determination
Adaptive filter for estimating system noise inputs from actual residuals developed to control Kalman filter in satellite orbit estimation
Filtering optimization prior to limiting digital signals in strong noise, detailing bandwidth choice of single pole low pass filter
Adaptive filtering to prevent divergence observed in application of Kalman filter to orbit determination
Filters, formed by combinations of distributed RC elements with positive-feedback voltage amplifiers, provide transfer functions similar to those the heavier LC filters ordinarily employ. They also provide signal amplification.
Self-tuning filter automatically adjusts its center frequency to track signal frequency. This permits the use of a filter with a bandwidth smaller than the range of input signal frequencies.
Resistance-capacitance RC filter coupled to a high input impedance receiver preamplifier provides signal isolation from an RF transmitter. High isolation is achieved by minimizing the inductive impedance to ground and using the distributed capacitance of the filter components.