scholarly journals Multi-parameter Tikhonov regularization-based OTPA with application to ship-radiated noise evaluation

AIP Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 015240
Author(s):  
Ruibiao Li ◽  
Wenjun Bu
Keyword(s):  
Tikhonov Regularization ◽  
Radiated Noise ◽  
Noise Evaluation

Power generator noise evaluation considering conversation audibility and improvement

2021 ◽  
Vol 263 (5) ◽  
pp. 1784-1793
Author(s):  
Junji Yoshida ◽  
Yoshiki Nishimura ◽  
Senta Uegaki
Keyword(s):  
Frequency Band ◽  
Correct Answer ◽  
Large Contribution ◽  
Target Level ◽  
Noise Condition ◽  
Power Generator ◽  
Power Generators ◽  
Radiated Noise ◽  
Living Space ◽  
Noise Evaluation

Compact power generators are useful and convenient tools all over the world. The products are mainly set at around living space of human. Hence, the radiated noise should not disturb the human activities such as conversation. In this study, we then focused on the ease of conversation as the power generator noise performance and attempted to improve the performance. We firstly carried out subjective evaluate tests using recorded generator noise samples and reproduced Japanese syllables to evaluate the performance quantitatively from sound pressure of power generator noise. In the test, the participants answered the syllable they heard under the reproduced generator noise condition. And the correct answer rate of the presented syllable was calculated in each generator noise. The correct answer rate could be expressed well by using articulation index (AI) of each generator noise. Subsequently, the noise reduction target level of a portable generator satisfying the rate at 80% was set in each frequency band considering the influence of each frequency band on AI. Noise countermeasure was carried out to intake and exhaust parts having large contribution at the reduction target frequency bands. Finally, the noise could be decreased well and the AI cleared the target level.

Modeling Vibration-Induced Tire-Pavement Interaction Noise in the Mid-frequency Range

2020 ◽  
Author(s):  
Sterling McBride ◽  
Ricardo Burdisso ◽  
Corina Sandu
Keyword(s):  
Sound Intensity ◽  
Element Model ◽  
Dominant Frequency ◽  
Contact Forces ◽  
Surface Velocity ◽  
New Wave ◽  
Normal Surface ◽  
Radiated Noise ◽  
Physical Effects ◽  
Effects Of Rotation

ABSTRACT Tire-pavement interaction noise (TPIN) is one of the main sources of exterior noise produced by vehicles traveling at greater than 50 kph. The dominant frequency content is typically within 500–1500 Hz. Structural tire vibrations are among the principal TPIN mechanisms. In this work, the structure of the tire is modeled and a new wave propagation solution to find its response is proposed. Multiple physical effects are accounted for in the formulation. In an effort to analyze the effects of curvature, a flat plate and a cylindrical shell model are presented. Orthotropic and nonuniform structural properties along the tire's transversal direction are included to account for differences between its sidewalls and belt. Finally, the effects of rotation and inflation pressure are also included in the formulation. Modeled frequency response functions are analyzed and validated. In addition, a new frequency-domain formulation is presented for the computation of input tread pattern contact forces. Finally, the rolling tire's normal surface velocity response is coupled with a boundary element model to demonstrate the radiated noise at the leading and trailing edge locations. These results are then compared with experimental data measured with an on-board sound intensity system.

Compact Energy Measuring System for Short Pulse Lasers

2013 ◽  
Vol 20 (2) ◽  
pp. 183-190 ◽  
Author(s):  
A. Barna ◽  
I. B. Földes ◽  
Z. Gingl ◽  
R. Mingesz
Keyword(s):  
Short Pulse ◽  
Electronic Devices ◽  
Laser Pulses ◽  
Measuring System ◽  
Electric Response ◽  
Usb Interface ◽  
Radiated Noise ◽  
Fiber Optical ◽  
Measurement Control ◽  
Short Pulse Lasers

Abstract In experiments with short-pulse lasers the measurement control of the energy of the laser pulse is of crucial importance. Generally it is difficult to measure the amplitude of the pulses of short-pulse lasers using electronic devices, their response time being longer than the duration of the laser pulses. The electric response of the detector is still too fast to be directly digitized therefore a peak-hold unit can be used to allow data processing for the computer. In this paper we present a device which measures the energy of UV short (fs) pulses shot-byshot, digitizes and sends the data to the PC across an USB interface. The circuit is based on an analog peak detect and hold unit and the use of fiber optical coupling between the PC and the device provides a significant improvement to eliminate potential ground loops and to reduce conductive and radiated noise as well. The full development is open source and has been made available to download from our web page (http://www.noise.inf.u-szeged.hu/Instruments/PeakHold/).

Noise evaluation of small airfields

1999 ◽  
Vol 47 (4) ◽  
pp. 125-132
Author(s):  
Per V. Bruel
Keyword(s):  
Noise Evaluation

Control of radiated noise from a ship’s cabin floor using a floating floor

2009 ◽  
Vol 57 (5) ◽  
pp. 507 ◽  
Author(s):  
Won-Ho Joo ◽  
Sung-Hoon Kim ◽  
Jong-Gug Bae ◽  
Suk-Yoon Hong
Keyword(s):  
Radiated Noise
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