Results 261 to 270 of about 240,426 (307)
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Input impedance and output impedance of feedback amplifiers
IEE Proceedings - Circuits, Devices and Systems, 1996A simple and precise method is given for calculating the input and output impedances of a feedback amplifier, directly from its loop gain. A useful approximation to the precise result is that the input or output impedance is equal to the source or load impedance for which loop gain would equal unity.
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Parametric models for characterizing respiratory input impedance
Journal of Medical Engineering & Technology, 2008This study compares a manifold of parametric models reported in the literature with two novel parametric models for identifying human input respiratory impedance. The analysis is carried out on typical patient data obtained with the forced oscillations technique (FOT), on three sets of representative diagnosed subjects: healthy, asthma and COPD.
C, Ionescu, R, de Keyser
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Acoustic Input Impedance of the Human Ear
Acta Oto-Laryngologica, 1966An objective method of measuring the vibrations of the tympanic membrane by means of an improved capacitive-probe system is described. The device has a dynamic range up to 7500 A over the whole audiofrequency range. A new probe tip was developed, serving for conduction of the modulated H.F. signal as well as for the sound transmission.
H, Fischler +4 more
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Differential amplifier input impedance and Blackman's impedance relation
IEEE Transactions on Electron Devices, 1972Recently the input impedance of a differential amplifier was derived and discussed. This correspondence derives similar results using a different approach, namely, Blackman's impedance relation, and generalizes earlier observations. The results provide an alternative active RC realization of a bilinear RL impedance.
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Optimal Damping of EMI Filter Input Impedance
IEEE Transactions on Industry Applications, 2009Input filter damping has long been recognized as critical for avoiding unintended interactions with a switching power converter. This paper investigates a related problem -dynamic interactions between a converter input filter and the source - and develops optimal damping designs that minimize the dipping in the input impedance of a filter seen by the ...
null Lei Xing, F. Feng, null Jian Sun
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A parametric study of cochlear input impedance
The Journal of the Acoustical Society of America, 1991In this paper various aspects of the cat cochlear input impedance Zc(ω) are implemented using a transmission line model having perilymph viscosity and a varying cross-sectional scalae area. These model results are then compared to the experimental results of Lynch et al. [J. Acoust. Soc. Am. 72, 108–130 (1982)].
S, Puria, J B, Allen
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Aortic input impedance in infants and children
Journal of Applied Physiology, 2000Flow and pressure measurements were performed in the ascending aortas of six pediatric patients ranging in age from 1 to 4 yr and in weight from 7.2 to 16.4 kg. From these measurements, input impedance was calculated. It was found that total vascular resistance decreased with increasing patient weight and was approximately one to three times higher ...
M K, Sharp +5 more
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Respiratory input impedance in anesthetized paralyzed patients
Journal of Applied Physiology, 1990Respiratory impedance (Zrs) was measured between 0.25 and 32 Hz in seven anesthetized and paralyzed patients by applying forced oscillation of low amplitude at the inlet of the endotracheal tube. Effective respiratory resistance (Rrs; in cmH2O.l-1.s) fell sharply from 6.2 +/- 2.1 (SD) at 0.25 Hz to 2.3 +/- 0.6 at 2 Hz.
D, Navajas +4 more
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Measurement of aortic input impedance in rats
American Journal of Physiology-Heart and Circulatory Physiology, 1994Measurement of aortic input impedance in the rat is complicated by a high basal heart rate but is possible if appropriate compensation is made for frequency-dependent errors in modulus and phase resulting from analog filters in the equipment and from nonalignment of pressure and flow sensors.
G F, Mitchell +3 more
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Mechanical input impedance of human teethin vivo
Medical & Biological Engineering, 1968The mechanical input impedance of teethin vivo has been measured over the frequency range of 60–5000 c/s. A generator was used which delivered a sinusoidal force of variable frequency and constant peak-to-peak amplitude of 4·4×104 dyn. Our data plus those of others indicate that the suspensory apparatus of the tooth consists of several equivalent ...
D H, Noyes, J W, Clark, C E, Watson
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