Results 271 to 280 of about 5,871,149 (318)
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Frequency Modulation and the Difference Limen for Frequency
The Journal of the Acoustical Society of America, 1969A system for tracking difference limen for frequency (ΔF) is described. The system uses a function generator to frequency modulate a BFO. The amplitude of the modulating voltage is controlled by a recording attenuator. Intuitive spectral analysis of the modulated tone proves to be insufficient and correction factors are given to allow determination of ...
L L, Feth, R V, Wolf, R C, Bilger
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Instantaneous frequency and time-frequency distributions
1995 International Conference on Acoustics, Speech, and Signal Processing, 2002It is generally stated that the conditional mean frequency of a time-frequency distribution (TFD) should equal the instantaneous frequency of the signal. The commonly accepted definition of instantaneous frequency as the derivative of the phase of the analytic signal sometimes leads to curious results.
Berkant Tacer, Patrick J. Loughlin
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Frequency selectivity for frequencies below 100 Hz: Comparisons with mid-frequencies
The Journal of the Acoustical Society of America, 2010Auditory filter shapes were derived for signal frequencies (fs) between 50 and 1000 Hz, using the notched-noise method. The masker spectrum level (N0) was 50 dB (re 20 μPa). For fs = 63 and 50 Hz, measurements were also made with N0 = 62 dB for the lower band.
Orellana, Carlos Andrés Jurado +1 more
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A frequency multiplier for reference frequency in frequency synthesizer systems
Analog Integrated Circuits and Signal Processing, 2017A low jitter frequency multiplier, which requires less power, area, and design complexity than reference multiplying PLL or DLL circuits can be used to generate the reference frequency for a low phase noise frequency synthesizer. This paper proposes a mixed signal solution based on the fact that the average DC value of a signal is proportional to its ...
Ihsan F. I. Albittar, Hakan Dogan
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Frequency standards and frequency measurement
Reports on Progress in Physics, 2002Recent years have brought major breakthroughs in the development, operation and mutual comparison of frequency standards in the microwave as well as in the optical frequency domain. Several cold-atom fountains have been developed, using caesium as well as rubidium atoms. Some of them have been compared among each other. Mutual agreement of the order of
A Bauch, H R Telle
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Dynamics of Frequency Estimation in the Frequency Domain
IEEE Transactions on Instrumentation and Measurement, 2007The possibility of error reduction in frequency estimations with a multipoint interpolated discrete Fourier transformation (DFT) for the Hanning window is described. An estimation of the periodic parameter by the interpolation of the DFT gives the same effect as the reduction of spectrum tails.
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Advances in Adaptive Data Analysis, 2009
Instantaneous frequency (IF) is necessary for understanding the detailed mechanisms for nonlinear and nonstationary processes. Historically, IF was computed from analytic signal (AS) through the Hilbert transform. This paper offers an overview of the difficulties involved in using AS, and two new methods to overcome the difficulties for computing IF ...
Norden E. Huang +5 more
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Instantaneous frequency (IF) is necessary for understanding the detailed mechanisms for nonlinear and nonstationary processes. Historically, IF was computed from analytic signal (AS) through the Hilbert transform. This paper offers an overview of the difficulties involved in using AS, and two new methods to overcome the difficulties for computing IF ...
Norden E. Huang +5 more
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Aircraft Engineering and Aerospace Technology, 1942
IN the article on simultaneous equations published in AIRCRAFT ENGINEERING, Vol. XI, May, 1939, pp. 199–200, the author exploited the powerful process of iteration. In the present article he deals similarly with an iterative method for finding the roots of a determinantal equation. Such a method was first given by Duncan and Collar in their paper “On a
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IN the article on simultaneous equations published in AIRCRAFT ENGINEERING, Vol. XI, May, 1939, pp. 199–200, the author exploited the powerful process of iteration. In the present article he deals similarly with an iterative method for finding the roots of a determinantal equation. Such a method was first given by Duncan and Collar in their paper “On a
openaire +2 more sources