Comparison of F o Extraction Methods for High-Precision Voice Perturbation Measurements

1993 ◽  
Vol 36 (6) ◽  
pp. 1120-1133 ◽  
Author(s):  
Ingo R. Titze ◽  
Haixiang Liang
Keyword(s):  
High Precision ◽  
Amplitude Modulation ◽  
Extraction Method ◽  
Signal To Noise Ratio ◽  
Extraction Methods ◽  
Sampling Frequency ◽  
Peak Picking ◽  
Signal To Noise ◽  
Zero Crossing ◽  
Software Implementations

Voice perturbation measures, such as jitter and shimmer, depend on accurate extraction of fundamental frequency (F o ) and amplitude of various waveform types. The extraction method directly affects the accuracy of the measures, particularly if several waveform types (with or without formant structure) are under consideration and if noise and modulation are present in the signal. For frequency perturbation, high precision is defined here as the ability to extract F o to ±0.01% under conditions of noise and modulation. Three F o -extraction methods and their software implementations are discussed and compared. The methods are cycle-to-cycle waveform matching, zero-crossing and peak-picking. Interpolation between samples is added to make the extractions more accurate and reliable. The sensitivity of the methods to different parameters such as sampling frequency, mean F o , signal-to-noise ratio, frequency modulation, and amplitude modulation are explored.

Improving Switched Current Sigma Delta Modulators’ Performances via the Particle Swarm Optimization Technique

2012 ◽  
pp. 154-170
Author(s):  
M. Fakhfakh ◽  
S. Masmoudi ◽  
Y. Cooren ◽  
M. Loulou ◽  
P. Siarry
Keyword(s):  
Signal To Noise Ratio ◽  
Optimization Technique ◽  
Memory Cell ◽  
Sampling Frequency ◽  
Embryonic Cell ◽  
Signal To Noise ◽  
Swarm Optimization ◽  
Sigma Delta ◽  
Switched Current ◽  
Particle Swarm Optimization Technique

This paper presents the optimal design of a switched current sigma delta modulator. The Multi-objective Particle Swarm Optimization technique is adopted to optimize performances of the embryonic cell forming the modulator, that is, a class AB grounded gate switched current memory cell. The embryonic cell was optimized regarding to its main performances such as sampling frequency and signal to noise ratio. The optimized memory cell was used to design the switched current modulator which operates at a 100 MHz sampling frequency and the output signal spectrum presents a 45.75 dB signal to noise ratio.

Improving Switched Current Sigma Delta Modulators' Performances via the Particle Swarm Optimization Technique

2010 ◽  
Vol 1 (2) ◽  
pp. 18-33 ◽  
Author(s):  
M. Fakhfakh ◽  
S. Masmoudi ◽  
Y. Cooren ◽  
M. Loulou ◽  
P. Siarry
Keyword(s):  
Signal To Noise Ratio ◽  
Optimization Technique ◽  
Memory Cell ◽  
Sampling Frequency ◽  
Embryonic Cell ◽  
Signal To Noise ◽  
Swarm Optimization ◽  
Sigma Delta ◽  
Switched Current ◽  
Particle Swarm Optimization Technique

This paper presents the optimal design of a switched current sigma delta modulator. The Multi-objective Particle Swarm Optimization technique is adopted to optimize performances of the embryonic cell forming the modulator, that is, a class AB grounded gate switched current memory cell. The embryonic cell was optimized regarding to its main performances such as sampling frequency and signal to noise ratio. The optimized memory cell was used to design the switched current modulator which operates at a 100 MHz sampling frequency and the output signal spectrum presents a 45.75 dB signal to noise ratio.

Signal-to-Noise Ratio Estimation in Electromyography Signals Contaminated with Electrocardiography Signals

2020 ◽  
Vol 19 (03) ◽  
pp. 2050027
Author(s):  
Thandar Oo ◽  
Pornchai Phukpattaranont
Keyword(s):  
Signal To Noise Ratio ◽  
Training Data ◽  
Signal To Noise ◽  
Zero Crossing ◽  
Ecg Signals ◽  
Average Value ◽  
Emg Signal ◽  
Recognition Systems ◽  
Noise Ratio ◽  
Electromyography Signals

When electromyography (EMG) signals are collected from muscles in the torso, they can be perturbed by the electrocardiography (ECG) signals from heart activity. In this paper, we present a novel signal-to-noise ratio (SNR) estimate for an EMG signal contaminated by an ECG signal. We use six features that are popular in assessing EMG signals, namely skewness, kurtosis, mean average value, waveform length, zero crossing and mean frequency. The features were calculated from the raw EMG signals and the detail coefficients of the discrete stationary wavelet transform. Then, these features are used as inputs to a neural network that outputs the estimate of SNR. While we used simulated EMG signals artificially contaminated with simulated ECG signals as the training data, the testing was done with simulated EMG signals artificially contaminated with real ECG signals. The results showed that the waveform length determined with raw EMG signals was the best feature for estimating SNR. It gave the highest average correlation coefficient of 0.9663. These results suggest that the waveform length could be deployed not only in EMG recognition systems but also in EMG signal quality measurements when the EMG signals are contaminated by ECG interference.

The Nth‐root stack: Theory, applications, and examples

Geophysics ◽  
1986 ◽  
Vol 51 (10) ◽  
pp. 1879-1892 ◽  
Author(s):  
P. L. McFadden ◽  
B. J. Drummond ◽  
S. Kravis
Keyword(s):  
Contrast Enhancement ◽  
Signal To Noise Ratio ◽  
Beam Steering ◽  
Seismic Refraction ◽  
Signal Distortion ◽  
Signal Attenuation ◽  
Signal To Noise ◽  
Zero Crossing ◽  
Array Data ◽  
Noise Ratio

Multichannel geophysical data are usually stacked by calculating the average of the observations on all channels. In the Nth‐root stack, the average of the Nth root of each observation is raised to the Nth power, with the signs of the observations and average maintained. When N = 1, the process is identical to conventional linear stacking or averaging. Nth‐root stacking has been applied in the processing of seismic refraction and teleseismic array data. In some experiments and certain applications it is inferior to linear stacking, but in others it is superior. Although the variance for an Nth‐root stack is typically less than for a linear stack, the mean square error is larger, because of signal attenuation. The fractional amount by which the signal is attenuated depends in a complicated way on the number of data channels, the order (N) of the stack, the signal‐to‐noise ratio, and the noise distribution. Because the signal‐to‐noise ratio varies across a wavelet, peaking where the signal is greatest and approaching zero at the zero‐crossing points, the attenuation of the signal varies across a wavelet, thereby producing signal distortion. The main visual effect of the distortion is a sharpening of the legs of the wavelet. However, the attenuation of the signal is accompanied by a much greater attenuation of the background noise, leading to a significant contrast enhancement. It is this sharpening of the signal, accompanied by the contrast enhancement, that makes the technique powerful in beam‐steering applications of array data. For large values of N, the attenuation of the signal with low signal‐to‐noise ratios ultimately leads to its destruction. Nth‐root stacking is therefore particularly powerful in applications where signal sharpening and contrast enhancement are important but signal distortion is not.

A High Bandwidth Sigma-Delta Modulator Applied in Micro-Gyroscope

2013 ◽  
Vol 562-565 ◽  
pp. 369-373 ◽  
Author(s):  
Qiang Fu ◽  
Wei Ping Chen ◽  
Song Chen ◽  
Peng Fei Wang ◽  
Xiao Wei Liu
Keyword(s):  
Signal To Noise Ratio ◽  
System Simulation ◽  
Sampling Frequency ◽  
Effective Number ◽  
Signal To Noise ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
High Bandwidth ◽  
Oversampling Ratio ◽  
Input Level

In this paper a fourth-order single-loop sigma-delta modulator applied in micro-gyroscope is designed. The modulator system chose the fully feedforword structure. The signal bandwidth is 200KHz, oversampling ratio is 64 and sampling frequency is 25.6MHz. By system simulation result in Matlab, the signal to noise ratio (SNR) is 92.3dB and effective number of bits (ENOB) is 15.03bits. The whole circuit of modulator is designed and simulated in Cadence Spectre. It is gotten that the SNR is 78.6dB and changes linearly with input level. When input level is bigger than -4dBFs, the modulator becomes overload.

scholarly journals Simultaneous Determination of Dapsone and Pyrimethamine by Derivative Spectrophotometry in Pharmaceutical Formulations

2003 ◽  
Vol 86 (2) ◽  
pp. 241-245 ◽  
Author(s):  
M Inés Toral ◽  
Andrés Tassara ◽  
César Soto ◽  
Pablo Richter
Keyword(s):  
Simultaneous Determination ◽  
Signal To Noise Ratio ◽  
Pharmaceutical Formulations ◽  
Derivative Spectrophotometry ◽  
Fast Method ◽  
Signal To Noise ◽  
Zero Crossing ◽  
First Order ◽  
First Derivative

Abstract A simple and fast method was developed for the simultaneous determination of dapsone and pyrimethamine by first-order digital derivative spectrophotometry. Acetonitrile was used as a solvent to extract the drugs from the pharmaceutical formulations, and the samples were subsequently evaluated directly by digital derivative spectrophotometry. The simultaneous determination of both drugs was performed by the zero-crossing method at 249.4 and 231.4 nm for dapsone and pyrimethamine, respectively. The best signal-to-noise ratio was obtained when the first derivative of the spectrum was used. The linear range of determination for the drugs was from 6.6 × 10−7 to 2.0 × 10−4 and from 2.5 × 10−6 to 2.0 × 10−4 mol/L for dapsone and pyrimethamine, respectively. The excipients of commercial pharmaceutical formulations did not interfere in the analysis. Chemical and spectral variables were optimized for determination of both analytes. A good level of repeatability, 0.6 and 1.7% for dapsone and pyrimethamine, respectively, was observed. The proposed method was applied for the simultaneous determination of both drugs in pharmaceutical formulations.

High precision linear frequency modulation ranging system based on semiconductor laser

2018 ◽  
Vol 32 (11) ◽  
pp. 1850136 ◽  
Author(s):  
Mingyuan Xue ◽  
Cunxiao Gao ◽  
Linquan Niu ◽  
Shaolan Zhu ◽  
Na Guo ◽  
...  
Keyword(s):  
Semiconductor Laser ◽  
High Precision ◽  
Frequency Modulation ◽  
Signal To Noise Ratio ◽  
Linear Frequency Modulation ◽  
Repetition Frequency ◽  
Laser Ranging ◽  
Signal To Noise ◽  
Linear Frequency ◽  
Noise Ratio

Based on the linear frequency modulation (LFM) of semiconductor laser, a laser ranging system is built. The ranging precision of the system is about micron dimension with the repetition frequency of 100 kHz and a distance of 1–10 m. We analyzed the ranging precision experimentally. As the bandwidth increases, the ranging precision becomes higher and higher. When the bandwidth is fixed, as the distance increases, the signal-to-noise ratio (SNR) will decrease, which reduces the precision.

Determination of Ditalimfos by Liquid Chromatography

1986 ◽  
Vol 69 (1) ◽  
pp. 117-118
Author(s):  
Joseph H Lesser ◽  
Solomon E Massil ◽  
Itshak Ezra
Keyword(s):  
Liquid Chromatography ◽  
High Precision ◽  
Coefficient Of Variation ◽  
Linear Response ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Ultraviolet Detection ◽  
Bonded Phase ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for the determination of ditalimfos, 0,0-diethyI phthalimidophosphonothioate, is described. Bonded phase high precision LC using a mixture of n-hexane and chloroform as eluant afforded a capacity factor (k') of 2.3 for the analyte. Ditalimfos could be detected at 0.5 ppm (signal to noise ratio > 3) using ultraviolet detection at 254 nm. The detector afforded a linear response from 0.2 to 10.9 mg/mL when 10 μL of solution was injected and the coefficient of variation was ±0.5%. Structurally related fungicides and several common insecticides were successfully separated from the analyte under the chromatographic conditions of analysis.

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