noise performance
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2021 ◽  
Author(s):  
Kaifeng Dong ◽  
Kun Xu ◽  
Youyou Zhou ◽  
Chao Zuo ◽  
Leiming Wang ◽  
...  

Abstract A new type of weak signal detection system that combines the memristor and Van der pol-Duffing chaotic system has been proposed in this paper, and the dynamic characteristics of the system are studied. It is observed that the system can change from a chaotic state to a periodic state under different driving force amplitudes. Moreover, as compared with several classical chaotic oscillators, the numerical simulation results show that the system has stronger anti-noise performance with the detectable signal-to-noise ratio reaches -163dB, and has a wider detection range. Its detection accuracy is up to 1 × 10 −9 . More importantly, this paper provides the circuit implementation scheme of the system, and the weak signal can be detected with our designed circuit. This may offer a possible way for weak signal detection system with good performance in anti-noise performance, detection range and accuracy.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1536
Author(s):  
Chengjiang Zhou ◽  
Yunhua Jia ◽  
Haicheng Bai ◽  
Ling Xing ◽  
Yang Yang

Aiming at the disadvantages of low trend, poor characterization performance, and poor anti-noise performance of traditional degradation features such as dispersion entropy (DE), a fault detection method based on sliding dispersion entropy (SDE) is proposed. Firstly, a sliding window is added to the signal before extracting the DE feature, and the root mean square of the signal inside the sliding window is used to replace the signal in the window to realize down sampling, which enhances the trend of DE. Secondly, the hyperbolic tangent sigmoid function (TANSIG) is introduced to map the signals to different categories when extracting the DE feature, which is more in line with the signal distribution of mechanical parts and the monotonicity of the degradation feature is improved. For noisy signal, the introduction of locally weighted scatterplot smoothing (LOWESS) can remove the burrs and fluctuations of the SDE curve, and the anti-noise performance of SDE is improved. Finally, the SDE state warning line is constructed based on the 2σ criterion, which can determine the fault warning point in time and effectively. The state detection results of bearing and check valve show that the proposed SDE improves the trend, monotonicity, and robustness of the state tracking curve, and provides a new method for fault state detection of mechanical parts.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 35-36
Author(s):  
Kening Jiang ◽  
Adam Spira ◽  
Kelsie Full ◽  
Emmanuel Garcia ◽  
Frank Lin ◽  
...  

Abstract Speech-in-noise performance involves central auditory and cortical processing and is fundamental to communication. We investigated cross-temporal associations of habitual sleep duration and stages (1996-1998) with speech-in-noise performance (2016-2017) in a subset of the Atherosclerosis Risk in Communities Study participated in the Sleep Heart Health Study(N=755, 61±5 years, 53% female). Speech-in-noise performance was measured by Quick Speech-in-Noise Test; range:0-30; lower scores=worse performance. Time spent in each stage (stage 1;2;3/4;rapid eye movement (REM)) was measured by polysomnography. Habitual sleep duration was calculated by self-reported duration on weekdays and weekends. In models adjusting for demographic and disease covariates, every 10-minute increase in REM sleep was associated with better speech-in-noise performance (0.10 points,95% CI:0.00,0.21); every 1-hour increase in habitual sleep duration was associated with worse speech-in-noise performance (-1.28 points,95% CI:-2.49,-0.08) among participants sleep >8 hours. Long sleep duration might be a risk marker of speech-in-noise performance, but REM sleep might be a protective factor.


2021 ◽  
Author(s):  
◽  
Dayle Raymond Jellyman

<p>Beamforming filter optimization can be performed over a distributed wireless sensor network, but the output calculation remains either centralized or linked in time to the weights optimization. We propose a distributed method for calculating the beamformer output which is independent of the filter optimization. The new method trades a small decrease in signal to noise performance for a large decrease in transmission power. Background is given on distributed convex optimization and acoustic beamforming. The new model is described with analysis of its behaviour under independent noise. Simulation results demonstrate the desirable properties of the new model in comparison with centralized output computation.</p>


2021 ◽  
Author(s):  
◽  
Dayle Raymond Jellyman

<p>Beamforming filter optimization can be performed over a distributed wireless sensor network, but the output calculation remains either centralized or linked in time to the weights optimization. We propose a distributed method for calculating the beamformer output which is independent of the filter optimization. The new method trades a small decrease in signal to noise performance for a large decrease in transmission power. Background is given on distributed convex optimization and acoustic beamforming. The new model is described with analysis of its behaviour under independent noise. Simulation results demonstrate the desirable properties of the new model in comparison with centralized output computation.</p>


Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1518
Author(s):  
Haoyi Chen ◽  
Kai Yuan ◽  
Ming Yao ◽  
Jiawei Xiong

Many modern ionospheric studies rely on incoherent scatter radars (ISR) since this kind of radar is able to detect various ionospheric parameters over very long ranges. The performance of ISR significantly depends on its coding system. In recent decades, a new type of coding system, which is the so-called composite coding, was presented. It used to be constructed by using a certain code to modulate alternating code to achieve better detection resolution and anti-noise performance for ISRs. In the present study, a new composite coding system was presented, which is constructed based on complementary codes and alternating codes. In this paper, the performance of the new composite code will be compared with that of several traditional codes to show that the new composite code can help to improve the detection performance of the ISR. According to the analysis based on the ambiguity function, the present composite coding system helps to improve the range resolution and detection range for ISR detections. In addition, numerical tests on anti-noise performance show that the complementary composite coding system has a good anti-noise performance and helps to reduce the necessary times of incoherent integration. As a result, the composite coding system can improve the time resolution.


Author(s):  
N. R. Beysengulov ◽  
J. R. Lane ◽  
J. M. Kitzman ◽  
K. Nasyedkin ◽  
D. G. Rees ◽  
...  

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