Experimental study and modeling of the white noise sources in submicron Pand N-MOSFETs

2001 ◽  
Vol 48 (4) ◽  
pp. 1577-1586 ◽  
Author(s):  
V. Re ◽  
I. Bietti ◽  
R. Castello ◽  
M. Manghisoni ◽  
V. Speziali ◽  
...  
Keyword(s):  
Experimental Study ◽  
White Noise ◽  
Noise Sources

scholarly journals Solving Noise Pollution Issue Using Plenum Window with Perforated Thin Box

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 614
Author(s):  
Hsiao Mun Lee ◽  
Andi Haris ◽  
Kian Meng Lim ◽  
Jinlong Xie ◽  
Heow Pueh Lee
Keyword(s):  
White Noise ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Experimental Results ◽  
Frequency Range ◽  
Noise Mitigation ◽  
Noise Sources ◽  
Acoustic Performance ◽  
Common Noise ◽  
The Common

In the present study, a conventional plenum window was incorporated with perforated thin box in order to enhance its performance at frequency range which centralized at 1000 Hz as most of the common noise sources at city nowadays are centralizing around this frequency. The entire studies were conducted in a reverberation room. The effectiveness of jagged flap on mitigating diffracted sound was also studied. Three types of noises were examined in the current study—white noise, traffic noise and construction noises. The experimental results showed that the plenum window with perforated thin box could reduce 8.4 dBA, 8.7 dBA and 6.9 dBA of white, traffic and construction noises, respectively. The jagged flaps did not have significant effect on the plenum window’s noise mitigation performance. When frequencies were ranging from 800 Hz to 1250 Hz, when compared with the case of without perforated thin box, it was found that the perforated thin box had good acoustic performance where it was able to reduce additional 1.6 dBA, 1.6 dBA and 1.2 dBA of white, construction and traffic noises, respectively.

Scalable array of Gaussian white noise sources for analogue VLSI implementation

1995 ◽  
Vol 31 (17) ◽  
pp. 1457-1458 ◽  
Author(s):  
A. Dupret ◽  
P. Garda ◽  
E. Belhaire
Keyword(s):  
White Noise ◽  
Gaussian White Noise ◽  
Vlsi Implementation ◽  
Noise Sources ◽  
Analogue Vlsi

scholarly journals Anomalous diffusion for overdamped particles driven by cross-correlated white noise sources

2006 ◽  
Vol 73 (3) ◽  
Author(s):  
S. I. Denisov ◽  
A. N. Vitrenko ◽  
W. Horsthemke ◽  
P. Hänggi
Keyword(s):  
White Noise ◽  
Anomalous Diffusion ◽  
Noise Sources

Changes in masked thresholds of a harbour seal (Phoca vitulina) associated with angular separation of signal and noise sources

1994 ◽  
Vol 72 (11) ◽  
pp. 1863-1866 ◽  
Author(s):  
S. D. Turnbull
Keyword(s):  
White Noise ◽  
Pure Tone ◽  
Noise Source ◽  
Angular Separation ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Noise Sources ◽  
Detection Thresholds ◽  
Noise Masker ◽  
Significant Difference

The masked pure tone thresholds of a harbour seal (Phoca vitulina) were measured at various angles using a white noise masker. The white noise source was placed at 0°, 30°, 60°, and 90° relative to the midline of the seal's head (0°). The masked pure tone thresholds for each angle were determined at 2, 4, 8, and 16 kHz. As the angle separating the signal and noise sources increased from 0° to 90°, the critical ratios of the harbour seal decreased by 1–4 dB. This shift in masked thresholds from a reference point of 0° azimuth was significant (H = 10.374, df = 3,16, p < 0.05). No significant difference was found in masked thresholds between 0° and 30° or between 60° and 90°. This indicates that if a noise source is separated by more than 30° relative to the location of a vocalizing seal, signal detection thresholds will be enhanced and communication distances increased.

Experimental Study on a Notched Nozzle for Jet Noise Reduction

2011 ◽  
Author(s):  
T. Ishii ◽  
H. Oinuma ◽  
K. Nagai ◽  
N. Tanaka ◽  
Y. Oba ◽  
...  
Keyword(s):  
Experimental Study ◽  
Noise Reduction ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Mixing Layer ◽  
Jet Noise ◽  
Computational Prediction ◽  
Pressure Level ◽  
Far Field ◽  
Noise Sources

This paper describes an experimental study on a notched nozzle for jet noise reduction. The notch, a tiny tetrahedral dent formed at the edge of a nozzle, is expected to enhance mixing within a limited region downstream of the nozzle. The enhanced mixing leads to the suppression of broadband peak components of jet noise with little effect on the engine performance. To investigate the noise reduction performances of a six-notch nozzle, a series of experiments have been performed at an outdoor test site. Tests on the engine include acoustic measurement in the far field to evaluate the noise reduction level with and without the notched nozzle, and pressure measurement near the jet plume to obtain information on noise sources. The far-field measurement indicated the noise reduction by as much as 3 dB in terms of overall sound pressure level in the rear direction of the engine. The use of the six-notch nozzle though decreased the noise-benefit in the side direction. Experimental data indicate that the high-frequency components deteriorate the noise reduction performance at wider angles of radiation. Although the increase in noise is partly because of the increase in velocity, the penetration of the notches into the jet plume is attributed to the increase in sound pressure level in higher frequencies. The results of near-field measurement suggest that an additional sound source appears up to x/D = 4 due to the notches. In addition, the total pressure maps downstream of the nozzle edge, obtained using a pressure rake, show that the notched nozzle deforms the shape of the mixing layer, causing it to become wavy within a limited distance from the nozzle. This deformation of the mixing layer implies strong vortex shedding and thus additional noise sources. To improve the noise characteristics, we proposed a revised version of the nozzle on the basis of a computational prediction, which contained 18 notches that were smaller than those in the 6-notched nozzle. Ongoing tests indicate greater noise reduction in agreement with the computational prediction.

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