A phase sensitive parametric seismometer

1966 ◽  
Vol 56 (4) ◽  
pp. 947-959
Author(s):  
P. W. Rodgers
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Parametric Excitation ◽  
Steady State Response ◽  
Response Characteristics ◽  
State Response ◽  
Phase Sensitive

abstract The steady-state response characteristics of a seismometer do not depend on the phase of the input. A phase-dependent response is obtained by parametric excitation of the seismometer, which is achieved with an electromagnetic spring. A theory is developed for this device and comparisons are made with experimental data. The construction of the seismometer and its application are discussed.

Theoretical and Experimental Analysis of Nonlinear Dynamics in a Linear Compressor

2001 ◽  
Vol 124 (1) ◽  
pp. 152-154 ◽  
Author(s):  
Gyu-Sang Choe ◽  
Kwang-Joon Kim
Keyword(s):  
Steady State ◽  
Nonlinear Response ◽  
Dynamic Models ◽  
Steady State Response ◽  
Describing Function ◽  
Linear Compressor ◽  
Response Characteristics ◽  
State Response ◽  
Jump Phenomena ◽  
Method Effects

Steady-state nonlinear response characteristics of a linear compressor are investigated theoretically and experimentally. In the theoretical approach, motions of not only piston but also cylinder are considered and dynamic models for steady-state response predictions are formulated by applying the describing function method. Effects of piston mass on the jump phenomena are predicted by the derived models as an example of design parameter variation and compared with actual experimental results.

The Auditory Steady-State Response: Full-Term and Premature Neonates

2002 ◽  
Vol 13 (05) ◽  
pp. 260-269 ◽  
Author(s):  
Barbara Cone-Wesson ◽  
John Parker ◽  
Nina Swiderski ◽  
Field Rickards
Keyword(s):  
Steady State ◽  
Premature Infants ◽  
Modulation Frequency ◽  
Otoacoustic Emission ◽  
Full Term ◽  
Steady State Response ◽  
Pass Rates ◽  
Term Infants ◽  
State Response ◽  
Auditory Steady State Response

Two studies were aimed at developing the auditory steady-state response (ASSR) for universal newborn hearing screening. First, neonates who had passed auditory brainstem response, transient evoked otoacoustic emission, and distortion-product otoacoustic emission tests were also tested with ASSRs using modulated tones that varied in frequency and level. Pass rates were highest (> 90%) for amplitude-modulated tones presented at levels ≥ 69 dB SPL. The effect of modulation frequency on ASSR for 500- and 2000-Hz tones was evaluated in full-term and premature infants in the second study. Full-term infants had higher pass rates for 2000-Hz tones amplitude modulated at 74 to 106 Hz compared with pass rates for a 500-Hz tone modulated at 58 to 90 Hz. Premature infants had lower pass rates than full-term infants for both carrier frequencies. Systematic investigation of ASSR threshold and the effect of modulation frequency in neonates is needed to adapt the technique for screening.

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