• 제목/요약/키워드: noise reducing

검색결과 1,153건 처리시간 0.023초

고속철도 실내소음 저감을 위한 다중채널 ANC 시스템 모델링 (Multi-channel ANC System Modeling for Reducing KTX Interior Noise)

  • 장현석;김새한;이태오;구경완;이권순
    • 전기학회논문지
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    • 제61권7호
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    • pp.1069-1076
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    • 2012
  • We use largely two methods, how to control the noise of the KTX, they are the passive noise control method and the active noise control method. The passive noise control has been used in a variety of ways since the KTX opening day, but lately it has shown the technical limitations by being dropped sharply. So, it is getting important to conduct the research about ANC that is able to reduce the ambient noise when the environmental-factor changes and be installed easily. To reduce a three-dimensional closed-space sound field like a car of a high-speed rail is hard to do using single channel ANC control system. Therefore we have to model the paths of the noise exactly for reducing the noise. And the control speakers and the error mics should be designed for optimal position. In this paper, we designed the transfer functions for modeling the noise paths under the influence of the distance between control speakers & error mics and primary noise speaker in TEST-BED where there is modeled as actual interior of KTX. We have made the modeling and the simulations of interior environment of KTX car by using three frequency bands of 120Hz, 280Hz, 360Hz. After the modeling, we compared the performance of active noise control and also we analyzed what to affect with difference in distance. After comparing of the performance using Pure Tone 120Hz, 280Hz, 360Hz at each modeling and then we simulated ANC for KTX's interior noise which we measured really and analyzed.

공동주택 층간소음 저감을 위한 능동소음제어(ANC) 기술 적용가능성 분석 (Analysis of Applicability of Active Noise Control (ANC) technique for Reducing Inter-Floor Noise in Apartment Buildings)

  • 남진원;김호진;김준환;위혁;김중관
    • 한국구조물진단유지관리공학회 논문집
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    • 제26권5호
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    • pp.49-56
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    • 2022
  • 본 연구에서는 능동소음제어(ANC, Active Noise Control) 기술을 이용하여 공동주택의 층간소음을 저감시키는 시뮬레이션 기반 연구를 수행하였다. ANC의 층간소음 저감 활용 가능성을 검토하기 위하여 층간소음시험시설에서 가속도계와 소음 수집용 마이크로폰을 설치하여 임팩트볼 낙하에 의한 소음진동을 측정하여 Fx-LMS 알고리즘 기반의 능동소음제어 시뮬레이션을 수행하였다. 이 과정에서 적응제어 수렴계수 등의 최적 시뮬레이션 조건을 도출한 후 가속도계와 스피커 수량을 변수로 하는 수치 시뮬레이션을 통해 소음저감효과를 분석하여 제한된 조건에서 층간소음을 저감시킬 수 있는 것을 확인하였다.

음향 홀로그래피를 이용한 자동차 바람소리 성능개발 (AEROACOUSTIC NOISE REDUCTION OF AN AUTOMOBILE USING ACOUSTIC HOLOGRAPHY)

  • 김무상;남경욱
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.259-262
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    • 2006
  • This paper introduces the process of reducing the automobile wind noise by using acoustic holography. First, a microphone array scans a side or plane under an automible step-by-step. Second, a pressure on a source plane is calculated. Third process is to analyze how much individual sources contribute to interior noise. Fourth process is to control important noise sources determined by the contribution analysis. This paper deals with the entire process, theoretical and experimental problems.

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박막과의 연성에 의한 저주파 소음 저감 (Low frequency noise reduction by coupling with membrane)

  • 박수경;김양한
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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    • pp.148-152
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    • 1996
  • A method of deminishing low frequency noise by acoustic acoupling with compliant wall is described. The coupled governing equations and boundary conditions are derived and solved. The coupled system shows very interesting behavior in the low frequency region; in the low frequency, acoustic wave doesn't propagate, but decay to satisfy the boundary condition with the compliant wall. Henceforth using this mechanism, we propose a method of reducing low frequency noise, which is infact related with the physical properties of compliant wall. The method has been experimentally verified.

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An Effective Noise Estimator for Use in Noise Reduction

  • Han, Hag-Yong;Kwon, Ho-Min;Lee, Sung-Mok;Lee, Gi-Dong;Kang, Bong-Soon
    • Journal of information and communication convergence engineering
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    • 제9권1호
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    • pp.59-63
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    • 2011
  • Conventional noise reduction filtering schemes realize limited improvements of the peak signal-to-noise ratio (PSNR) in the low-level noisy images. The flatness degree and the edge information are effectively used to estimate the noise volume. We propose a noise estimator for reducing noise in the AWGN (additive white gaussian noise) corrupted images using three intermediate image maps (FGM(flatness gray map), FIM(flatness index map), NEM(noise estimate map)). The proposed noise estimator is fed into the conventional noise reduction filters as a pre-processor. The performance of noise reduction is tested in the various AWGN corrupted images.

철도용 고효율 친환경 경량방음터널 기술개발 (A Development of the Light Weight Noise Tunnel on a High Degree of Efficiency and Environmentally Friendly for Railway)

  • 손정곤;박광현;류래언
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 춘계학술대회 논문집
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    • pp.487-490
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    • 2014
  • These Days a lot of Noise Complaints in vicinity of Railway has been more increase than before. Almost 1/3 Residences who lives in Railway side are Exposure to Noise Pollution. Since the Apartment Buildings around Railway are getting more higher, so those of the Noise Barrier are not best solution anymore. We are going to make a New Plane with the state of the art technology for Railway Noise Abatement Control. Our Goal are focus on a development of Light Weight Noise Tunnel designed by new absorption mat'l and tunnel Stucture on the Overbridge and Viaduct of existing Railway. New Noise Tunnel will be reducing their weight more than 30% against Road Traffic One and also 10dB(A) Noise Reduction against Noise Barrier.

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가속주행하는 오토바이 흡배기계 시스템의 소음 저감에 관한 연구 (Study on the Intake/Exhaust Noise Reductions of Motorcycle Pass-by Noise)

  • 김봉기;김재승;김상렬;이상문;이태원;박근태
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.871-875
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    • 2001
  • Evaluation of the contribution of each pass-by noise source to the overall pass-by noise is an important issue for reduction of pass-by noise. A lead-wrapping test for analyzing pass-by noise of motorcycle is used to identify the principal noise sources of the pass-by noise in this study. Lead-wrapping test is employed and the contribution analysis is carried out. Based on the contribution analysis of each pass by noise source from the action of the prior tests, the design modifications of intake/exhaust systems were performed for reducing the pass-by noise. Finally, the pass-by noise test based on ISO362 was carried out to verify the noise reduction.

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