phase sensitive detector described here has two principal applications: a- to produce a d.c out put proportional to- the amplitude of an incoming a,c signal and indicate, by the outut polarity, the phase of the signal with respect to an internal reference. b- to detect the presence of a signal of known phase and frequency which would otherwise be lost in «background noise» and to measure its am...

Time shifts beyond the correlation time of the logic and reference signals create new elements that are orthogonal to the original components. This fact can be utilized to increase the number of dimensions of the logic space while keeping the number of reference noises fixed. Using just a single noise and time shifts can realize exponentially large hyperspaces with large numbers of dimensions. ...

Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com Lock-in amplifiers are used to detect and measure very small AC signalsall the way down to a few nanovolts. Accurate measurements may be made even when the small signal is obscured by noise sources many thousands of times larger. Lock-in amplifiers use a technique known as phase-sensitive detection to single out the component of t...

background: noise is one of the most important harmful agents in work environment. noise pollution in oil refinery industries is related to workers' health. this study aimed to determine the overall noise pollution of an oil refinery operation and its frequency analysis to determine the control plan for a vent noise in these industries. methods: this experimental study performed in control unit...

OBJECTIVE Railway workers performing maintenance work of trains and tracks could be at risk of developing noise-induced hearing loss, since they are exposed to noise levels of 75-90 dB(A) with peak exposures of 130-140 dB(C). The objective was to make a risk assessment by comparing the hearing thresholds among train and track maintenance workers with a reference group not exposed to noise and r...

Recently, in 2013 Feder et al. proposed the frequency increment test (FIT), which evaluates natural selection at a single diallelic locus by the use of time-series data of allele frequencies. This test is unbiased under conditions of constant population size and no sampling noise. Here, we expand upon the FIT by introducing a test that explicitly allows for changes in population size by using i...

The aim of this work is to study image quality of both single and multiply distorted images. We address the case of images corrupted by Gaussian noise or JPEG compressed as single distortion cases and images corrupted by Gaussian noise and then JPEG compressed, as multiply distortion case. Subjective studies were conducted in two parts to obtain human judgments on the single and multiply distor...

A 900-MHz phase-locked loop frequency synthesizer implemented in a 0.6m CMOS technology is developed for the Wireless Integrated Network Sensors applications. It incorporates an automatic switched-capacitor (SC) discrete-tuning loop to extend the overall frequency tuning range to 20%, while the VCO gain ( VCO) resulting from the CMOS varactor continuous-tuning is kept low at only 20 MHz/V in or...

High bandwidth, high resolution positioning is a significant enabling tool for nanotechnology. Unfortunately, in a typical nanopositioner operating in closed loop, higher bandwidth results in increased sensitivity to measurement noise and hence reduced resolution. In this article we present a technique that allows high-precision tracking of repetitive, jitter-free reference signals without bein...

Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com Lock-in amplifiers are used to detect and measure very small AC signalsall the way down to a few nanovolts. Accurate measurements may be made even when the small signal is obscured by noise sources many thousands of times larger. Lock-in amplifiers use a technique known as phase-sensitive detection to single out the component of t...