The transfer function of a short-period vertical seismograph

1961 ◽  
Vol 51 (4) ◽  
pp. 503-513
Author(s):  
B. P. Bogert
Keyword(s):  
Transfer Function ◽  
Frequency Response ◽  
Least Squares ◽  
Damping Ratio ◽  
Weighted Least Squares ◽  
Measured Frequency ◽  
Least Squares Fit ◽  
Short Period ◽  
Measured Frequency Response ◽  
Poles And Zeros

Abstract We locate the poles and zeros of the transfer function of a seismograph which consists of the Geotech Model 1051 Benioff vertical seismometer and the Geotech Model 4500 galvanometer-phototube amplifier with a 5 cps galvanometer. A weighted least squares fit to the measured frequency response of the seismometer, assuming a damping ratio of 17 to 1, gives for the pole locations of the seismometer transfer function: - 10 . 539 ; - 5 . 787 + i 7 . 407 ; - 5 . 787 - i 7 . 407 There is a triple zero at the origin. The overall seismograph transfer function has additional poles at - 22 . 21 + i 22 . 21 ; - 22 . 21 - i 22 . 21 ; - 0 . 06283 ; - 29 . 62 + i 29 . 62 ; - 29 . 62 - i 29 . 62 ; an additional zero at the origin, and a quadruple zero at infinity. an additional zero at the origin, and a quadruple zero at infinity.

A Simple Linearized Hot-Wire Anemometer

1976 ◽  
Vol 98 (4) ◽  
pp. 749-752 ◽  
Author(s):  
James A. Miller
Keyword(s):  
Transfer Function ◽  
Frequency Response ◽  
High Stability ◽  
Hot Wire ◽  
Measured Frequency ◽  
Measured Frequency Response ◽  
Incompressible Media ◽  
Very High

The circuit and application of an inexpensive simple linearized hot wire anemometer especially suited to turbulence research in incompressible media is described. Special features of the design are very high stability, simple bridge adjustment, and a linearizer having an adjustable exponent and very high transfer function accuracy. Measured frequency response is in excess of 100 kilohertz for the bridge and 7.5 kilohertz for the linearizer.

Calculation of Component Mode Synthesis Matrices From Measured Frequency Response Functions, Part 2: Application

1998 ◽  
Vol 120 (2) ◽  
pp. 509-516 ◽  
Author(s):  
J. A. Morgan ◽  
C. Pierre ◽  
G. M. Hulbert
Keyword(s):  
Frequency Response ◽  
Coupled System ◽  
Companion Paper ◽  
Component Mode Synthesis ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Measured Frequency ◽  
Measured Frequency Response ◽  
Coupled Beams ◽  
The Individual

This paper demonstrates how to calculate Craig-Bampton component mode synthesis matrices from measured frequency response functions. The procedure is based on a modified residual flexibility method, from which the Craig-Bampton CMS matrices are recovered, as presented in the companion paper, Part I (Morgan et al., 1998). A system of two coupled beams is analyzed using the experimentally-based method. The individual beams’ CMS matrices are calculated from measured frequency response functions. Then, the two beams are analytically coupled together using the test-derived matrices. Good agreement is obtained between the coupled system and the measured results.

scholarly journals Period Changes and Mass Loss Rates in 34 RS CVn-Type Binaries

1980 ◽  
Vol 88 ◽  
pp. 383-387 ◽  
Author(s):  
Douglas S. Hall ◽  
Jerzy M. Kreiner ◽  
Steven N. Shore
Keyword(s):  
Light Curve ◽  
Mass Loss ◽  
Least Squares ◽  
Weighted Least Squares ◽  
Astronomical Observatory ◽  
Astronomical Institute ◽  
Long Period ◽  
Sternberg Astronomical Institute ◽  
Short Period

We have collected all available times of minimum, over 1650, for 23 regular, 7 short-period, and 4 long-period eclipsing RS CVn binaries using the card catalogues at the Sternberg Astronomical Institute and the Krakow Astronomical Observatory, as well as unpublished data. We examined them critically, discarded those grossly in error, and assigned weights. For AD Cap, RV Lib, and ε UMi there are virtually no data. For the remaining 31 we determined quadratic ephemerides by weighted least squares. Values of d1nP/dt are given in the Table with their errors. Roughly 2/3 are variable at greater than the 2 σ level. Significant decreases outnumber significant increases by almost 2:1. We show that light curve asymmetry produced by the distortion wave probably accounts for the relatively small, rapid fluctuations in the O-C curve but not the long-term period changes.

scholarly journals A Two Channel Analog Front end Design AFE Design with Continuous Time Σ-Δ Modulator for ECG Signal

2018 ◽  
Vol 8 (6) ◽  
pp. 5041 ◽  
Author(s):  
Mohammed Abdul Raheem ◽  
K Manjunathachari
Keyword(s):  
Frequency Response ◽  
Research Work ◽  
Cmos Process ◽  
Type I ◽  
Sigma Delta ◽  
Front End ◽  
Measured Frequency ◽  
Analog Front End ◽  
Measured Frequency Response ◽  
Power Application

In this context, the AFE with 2-channels is described, which has high impedance for low power application of bio-medical electrical activity. The challenge in obtaining accurate recordings of biomedical signals such as EEG/ECG to study the human body in research work. This paper is to propose Multi-Vt in AFE circuit design cascaded with CT modulator. The new architecture is anticipated with two dissimilar input signals filtered from 2-channel to one modulator. In this methodology, the amplifier is low powered multi-VT Analog Front-End which consumes less power by applying dual threshold voltage. Type -I category 2 channel signals of the first mode: 50 and 150 Hz amplified from AFE are given to 2nd CT sigma-delta ADC. Depict the SNR and SNDR as 63dB and 60dB respectively, consuming the power of 11mW. The design was simulated in a 0.18 um standard UMC CMOS process at 1.8V supply. The AFE measured frequency response from 50 Hz to 360 Hz, depict the SNR and SNDR as 63dB and 60dB respectively, consuming the power of 11mW. The design was simulated in 0.18 m standard UMC CMOS process at 1.8V supply. The AFE measured frequency response from 50 Hz to 360 Hz, programmable gains from 52.6 dB to 72 dB, input referred noise of 3.5 μV in the amplifier bandwidth, NEF of 3.

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