• Title, Summary, Keyword: Noise Analysis

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Study on the Annoyance Response in the Area Exposed by Road Traffic Noise and Railway Noise (도로교통소음과 철도소음 복합노출지역에서의 성가심 반응)

  • Ko, Joon-Hee;Chang, Seo-Il;Son, Jin-Hee;Lee, Kun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.2
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    • pp.172-178
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    • 2010
  • The multiple regression analysis and path analysis in each dominant area of noise source are conducted to analyze the relationship between dependent variables like annoyance and independent ones such as noise and non-noise factors. The multiple regression analysis shows that impact of noise factors is the highest to annoyance in dominant areas of road traffic and railway noise. Meanwhile, impact of non-noise factors such as sensitivity and satisfaction of environment on annoyance is also high in these areas. The path analysis result for multivariate analysis between various independent and dependent variables is similar to that of the multiple regression analysis. However, noise factor is the greatest factor influent on annoyance in the dominant areas of the combined noise, and relationship between annoyance and sensitivity is the highest in combined area exposed to road traffic noise and railway noise.

Transfer Path Analysis of Output Noise Using Multi-dimensional Spectral Analysis Method for Vacuum Cleaner (다차원 스펙트럼 해석법을 이용한 진공청소기 출력소음의 전달경로 해석)

  • Jeong, Jae-Eun;Lee, Jung-Hwan;Chung, Chang-Ook;Hwang, Geun-Bae;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.10
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    • pp.940-945
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    • 2010
  • Noise reduction of vacuum cleaner is important, according as get into standard that estimate quality of product. To reduce noise of vacuum cleaner, we need analysis of correct noise source and contribution grasping about Identified noise sources' output noise. Because noise sources' correlation exists in vacuum cleaner that is small and complicated system, analysis is not easy. In this case, we need to apply Multi-dimensional spectral analysis(MDSA) method that can remove correlation between noise sources and grasp pure contribution degree of noise sources. In this study, we take transfer path analysis between output noise and noise that measured in inside/outside of vacuum cleaner.

Prediction Of Vibrating Panel's Radiating Noise By Transfer Path Analysis (전달경로해석법에 의한 진동하는 판넬의 방사 소음 예측)

  • Oh, Jae-Eung;Lee, Sun-Hun;Jeong, Un-Chang;Kim, Jin-Su;Lee, You-Yup
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.292-293
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    • 2014
  • Transfer Path Analysis is technique predicting transmitted energy through each path. Using the Transfer Path Analysis, structure-borne noise and air-borne noise can be predicted from the system. In this study, however, the Transfer Path Analysis to target only the structure-borne noise due to the noise radiated from the vibrating panel was performed. Predicted noise by the Transfer Path Analysis and measured noise by the experiment were a high correlation. We confirmed the validity of the Transfer Path Analysis through the analysis of these results, showed how to apply the Transfer Path Analysis.

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The Sound Quality Analysis of Environmental noise by Jury Testing (주관평가 방법에 의한 환경소음 음질평가)

  • 조경숙;허덕재;조연
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.712-717
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    • 2004
  • Recently, the concern for the environmental noise has increased due to the growing of the living standard. The environmental noise regulations based on the equivalent noise level are widely used. However, the noise level, which Is based mainly on the magnitude with A-weighting, the important characteristics of noises in frequency and time domains and the impulsive nature cannot be assessed properly. These can have substantial effects on how human respond to noise. Therefore, the noise evaluation methodology based on the sound quality rather than the equivalent noise level can be more suitable to represent human response to the environmental noise. This paper describes the study on environmental noise quality analysis for various noises. A cluster analysis was carried out and the noises were classified into several clusters using the values of sound quality metrics. The classification was confirmed by comparing time and frequency characteristics of the noises. And then the result of Jury testing was analysis.

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Improvement of Sound Quality of Vehicle Through Reduction of Interior Noise Using Noise Transfer Path Analysis and Running Modal Analysis (소음 전달 결로 해석 및 주행 모두 해석을 이용한 차량의 실내소음 저감을 통한 음색 향상)

  • 이상권;황우석;김중희;우재학;이상희;이학준
    • Journal of KSNVE
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    • v.10 no.5
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    • pp.806-810
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    • 2000
  • This paper presents a practical method for reduction of interior noise and improvement of sound quality in compartment of passenger car. The tested vehicle has a booming noise problem at rear passenger seats. In order to identify the transfer path of interior noise, the running modal analysis, the vibro-acoustic frequency transfer response and the noise path analysis are systematically employed. Using these various methods, it has been founded that the rear part of the roof of the test car was a noise source for the booming noise. Through the modification of the roof, the booming noise has been reduced and sound quality inside car also has been improved.

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Experimental Analysis on Barrel Zoom Module of Digital Camera for Noise Source Identification and Noise Reduction (실험적 방법을 이용한 디지털 카메라 경통 줌 모듈의 소음원 규명 및 저소음화)

  • Kwak, Hyung-Taek;Jeong, Jae-Eun;Jeong, Un-Chang;Lee, You-Yub;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.11
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    • pp.1074-1083
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    • 2011
  • Noise of digital camera has been noticeable to its users. Particularly, noise of a barrel assembly module in zoom in/zoom out operation is recorded while taking a video. Reduction of barrel noise becomes crucial but there are not many studies on noise of digital camera due to its short history of use. In this study, experiment-based analyses are implemented to identify sources of noise and vibration because of complexity and compactness of the barrel system. Output noise is acquired in various operation conditions using synchronization for spectral analysis. Noise sources of a barrel assembly in zoom operating are first identified by the comparison with gear frequency analysis and then correlation analysis between noise and vibration is applied to confirm the generation path of noise. Analysis on noise transfer characteristic of zoom module is also carried out in order to identify the most contributing components. One of possible countermeasures of noise in zoom operating is investigated by an experimental approach.

Multiple Noise Analysis and Derivation of Noise Prediction Equations for Shelter System (쉘터시스템 복합소음분석 및 소음예측수식 유도)

  • Cho, Jae-sang;Lee, Sock-kyu;Baek, In-gi;Kim, Sang-hyun;Lee, Jeung;Choi, Ji-ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.5
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    • pp.616-624
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    • 2016
  • Design of shelter system requires consideration of noise at operators’ positions, because noise can injure person’s health. That is why studies which analyze and predict noise at operator’s positions is essential. To analyze noise sources of shelter system, this study measured noise of each equipment and obtained new equations by comparing the measured noise data and the equation which is relation noise and distance. The new equations predict noise level at operators’ positions. Actran analysis is performed to obtain noise level at operators’ positions too. At last, the noise level at operators’ positions measured in real shelter system is compared with the noise level predicted the new equations and Actran analysis.

Interior Noise Reduction Using Sensitivity Analysis and Structural Dynamic Modification (민감도 해석 및 구조 변경법을 이용한 차실 소음 저감)

  • 황우석
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1145-1151
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    • 1999
  • Sensitivity analysis and structural modification technique are used to reduce the interior noise of a passenger car. The sensitivity analysis for the noise level at the rear seat shows that the stiffness change at the front lower member and the rear roof rail are sensitive. Using the structural modification method, we verified that the reinforcements at those members decrease the noise transfer function from the body to the rear seat. The combined application of the sensitivity analysis and structural modification method can decrease the noise level effectively.

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Application of Air-Borne Noise Path Analysis to a real vehicle (실차에 대한 공기기인 소음경로분석법 적응)

  • Kim, Yoon-Jae;Jeong, Won-Tae;Song, Moon-Seong;Kang, Yeon-June;Kim, Hong-Bin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.699-702
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    • 2006
  • Noise Path Analysis is commonly used method to analysis noise transmission characteristics of a system. To analysis transfer paths of a system, it is necessary to know operating forces at each transfer path. The method to find out operating forces is divided into two methods. The one is a direct method which measures operating forces directly and the other is an indirect method which estimates operating forces mathematically. However, the indirect method is more commonly used because of the difficulty of measurement. This paper is focused on the indirect method and air-borne noise of a vehicle. Noise Path Analysis for Air-Borne Noise is applied to a real vehicle.

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The Study for Vibro-acoustic Noise Analysis in the Fuselage of Regional Turboprop Airplane (중형항공기 동체 소음해석 기법 연구)

  • Park, Illkyung;Kim, Sungjoon;Jung, Jinduck
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.20 no.3
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    • pp.44-50
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    • 2012
  • The noise reduction is important one of considerations in the process of a civil aircraft development program. External noise sources are classified into an air-born source and a structure-born source. Among these noise sources, the most affected noise source into a cabin is the air-born noise source from an engine or propeller. The external noise is transmitted into the cabin through the fuselage structure of airplane which are composed of an fuselage structure, an interior trim panel and an acoustic insulation layer between an fuselage structure and an interior trim panel. Therefore, appropriate fuselage structure and acoustic insulation layer is very important to reduce the internal noise level. In this paper, the vibro-acoustic coupled analysis of the cabin noise of the 80~90 seats regional turboprop aircraft is carried out to validate the acoustic analysis method using Direct BEM and FEM. The sound pressure level onto the fuselage skin is acquired by fan-source noise analysis using BEM, and which sound pressure is used as acoustic noise source in vibro-acoustic noise analysis for cabin noise analysis using FEM.