Experimental Evaluation of Wind Noise Sources: A Case Study

Author(s):  
William B. Coney ◽  
Jen Y. Her ◽  
Keith Tomaszewicz ◽  
Kevin Y. Zhang ◽  
James A. Moore
2019 ◽  
Vol 8 (6) ◽  
pp. 272 ◽  
Author(s):  
Iq Reviessay Pulshashi ◽  
Hyerim Bae ◽  
Hyunsuk Choi ◽  
Seunghwan Mun ◽  
Riska Asriana Sutrisnowati

Analysis of trajectory such as detection of an outlying trajectory can produce inaccurate results due to the existence of noise, an outlying point-locations that can change statistical properties of the trajectory. Some trajectories with noise are repairable by noise filtering or by trajectory-simplification. We herein propose the application of a trajectory-simplification approach in both batch and streaming environments, followed by benchmarking of various outlier-detection algorithms for detection of outlying trajectories from among simplified trajectories. Experimental evaluation in a case study using real-world trajectories from a shipyard in South Korea shows the benefit of the new approach.


2008 ◽  
Vol 123 (5) ◽  
pp. 3452-3452
Author(s):  
Robert Powell ◽  
Bijan Khatib‐Shahidi

Author(s):  
Ningning Liu ◽  
Yuedong Sun ◽  
Yansong Wang ◽  
Pei Sun ◽  
Wenwu Li ◽  
...  

Owing to the continuous development of the automobile industry, increasingly stringent performance requirements for noise, vibration, and harshness of automobiles are being presented. Interior noise control in high-speed vehicles has not been adequately addressed, owing to the complex mechanism of noise generation. As simulations performed previously focused on vehicle wind noise and tyre noise cannot adequately predict the effect on passenger ear-side noise, these issues are investigated in this study. Their effects on passengers are investigated using transfer path analysis. An anti-noise operational transfer path analysis is proposed to study noise generated in high-speed vehicles. The established anti-noise operational transfer path analysis model can eliminate crosstalks between noise source signals of different transmission paths. The model is validated by comparing the measured and calculated values of the anti-noise operational transfer path analysis model. The coherence of the input noise signal and the ear-side noise signal of the passenger is assessed using coherence analysis. By calculating and categorising the contributions of different noise sources in different locations and types, the main noise sources affecting passenger comfort are determined. The result indicates that the main noise sources affecting the passenger’s ear-side noise change from engine noise to left-A wind noise and tyre radiation noise with increasing vehicle speed, in which the proportion also increase. The proposed anti-noise operational transfer path analysis is suitable for the interior-noise analysis of high-speed vehicles, and this study may serve as a reference for future studies regarding active and passive noise control in high-speed vehicles.


Author(s):  
O'Neil Davion Delpratt ◽  
Michael Kay

This paper attempts to analyze the performance benefits that are achievable by adding a code generation phase to an XSLT or XQuery engine. This is not done in isolation, but in comparison with the benefits delivered by high-level query rewriting. The two techniques are complementary and independent, but can compete for resources in the development team, so it is useful to understand their relative importance. We use the Saxon XSLT/XQuery processor as a case study, where we can now translate the logic of queries into Java bytecode. We provide an experimental evaluation of the performance of Saxon with the addition of this feature compared to the existing Saxon product. Saxon's Enterprise Edition already delivers a performance benefit over the open source product using the join optimizer and other features. What can we learn from these to achieve further performance gains through direct byte code generation?


Author(s):  
Yasuhiko Okutsu ◽  
Naoki Hamamoto ◽  
Robert Powell ◽  
Long Wu

To control high frequency wind noise upper than 1 kHz is important to ensure the comfort for a driver and passengers when vehicles cruise at high speed. Therefore the prediction method for high frequency wind noise inside a cabin has been required for development of a vehicle. This paper describes about the prediction method for high frequency wind noise from numerical simulation results. In this study, wind noise caused by airflow around a front pillar is predicted. We have predicted wind noise by visualizing noise sources and pressure fluctuation on vehicle surfaces in recent years. Although an inferior-to-superior relationship can be predicted from these results, it was difficult to estimate quantitative interior noise level. In this research, the SEA code is examined to predict such noise level. The SEA code has confirmed showing a qualitative and almost quantitative consistency of measured and calculated SPL at the head area of a front passenger seat.


2012 ◽  
Vol 73 (8) ◽  
pp. 817-827 ◽  
Author(s):  
Gwang-Se Lee ◽  
Cheolung Cheong ◽  
Su-Hyun Shin ◽  
Sung-Soo Jung
Keyword(s):  

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