• Title/Summary/Keyword: Vibration & Noise

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A Study on the Characteristics of Railroad Noise and Vibration Propagation in KYOUNGBU Line (경부선 철도 소음진동의 전파특성에 관한 기초 연구)

  • 김석홍;이성춘;김준호
    • Journal of KSNVE
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    • v.3 no.1
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    • pp.47-55
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    • 1993
  • In order to maintain comfortable life environment around railroad site, noise from train itself, and to train & rail interaction, and the vibration transmitted through the ground should be controlled to the extent of permissible level. In order to achieve this, the basic railroad noise & vibration data such as magnitude and frequency characteristics of them are necessary to establish the counterplan for railroad noise & vibration. In this study, we measured and analysed the characteristics of time variation, frequency, direction and distance attenuation of noise and vibration of the railroad between Seoul and Pusan.

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A Trend of Noise and Vibration Research in Compressor (압축기의 소음 진동 연구 경향)

  • Wang, Semyung
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.509-513
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    • 2004
  • There are a lot of efforts to improve noise and vibration in compressor. It had depended on experiments to reduce the annoying noise and vibration raised by costumer complaints until the twentieth century. But a trend of noise and vibration research changed tremendously by simulation techniques. Simulation techniques are also applied to fields on acoustic and valve dynamics etc, to validate a experiment and improve the performance of various fields in noise and vibration.

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A Study on Noise Radiation of Compressor Shell (압축기 쉘의 방사소음에 관한 연구)

  • Chae, Seung-Hoon;Hwang, Won-Gul;Oh, Il-Kwon;Park, Sung-Woo;Ryu, Ki-O
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.164-167
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    • 2005
  • The noise level of refrigerating units is becoming more important to the manufacturer and the user of the product. Invariably, the compressor is a significant contributor to the overall noise level. Especially a major portion of the noise radiated by the vibration of the compressor shell. This paper presents an approach to relate the dynamic characteristics of the compressor shell with the noise radiation properties and the methods of redesigning the compressor shell to reduce the noise radiation. To relate the dynamic characteristics of the compressor shell with the noise radiation properties, the vibration and radiated sound were measured with the running compressor. Based on the results of these tests correlations between the shell vibration characteristics and the noise radiation properties are identified It was found that the vibration on the compressor shell and the noise radiated from the compressor were stronglycorrelatedincertainfrequencybands.

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investigation on Human Effects of Vibration and Noise Exposed on Human: I. Human Vibration (인체 진동소음의 인체영향에 대한 국내외 기술조사 : 인체 진동)

  • 정완섭;권휴상
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.691-694
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    • 2001
  • The recent national contract (Ecotechnopia 21) supported by the ministry of environment puts much significance on new issues for the assessment of human effects arising from vibration and noise exposed to human. This paper focuses only on hand-arm vibration since it has been a major problem in protecting vibration exposure to human. To set up a systematic way of assessing adverse effects of hand-arm vibration, surveys were made on recent international standards and researches related to hand-arm vibration. The measurement and evaluation methods of hand-arm transmitted vibration, the relationship between vibration exposure and effects on health, and the assessment methods of nerve dysfunctions are addressed in this paper. Those methods are linked into a logical way of assessing effects of hand-arm vibration on human. Finally, the current activities and achievements in this work are briefly summarised.

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Vibration and Noise Control of the Simply Supported Slab Using the Multi-tuned Mass Damper (다중동조질량감쇠기를 이용한 단순지지 슬래브의 진동 및 소음저감에 관한 연구)

  • Hwang, Jae-Seung;Hong, Geon-Ho;Park, Hong-Gun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.10
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    • pp.1006-1013
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    • 2008
  • In this study, it is outlined that heavy weight floor impact noise induced by the vibration of slab can be reduced using multi tuned mass damper(MTMD) effectively. Substructure synthesis is utilized to develope analytical model of the slab coupled with MTMD and acoustic power is introduced to evaluate the performance of noise control for simplicity. Numerical analysis is carried out to investigate the effect of the properties of MTMD on the vibration and noise control of the simply supported slab. Numerical analysis shows that mass ratio of MTMD is critical on the vibration and noise control of the slab and it is also essential to reduce the vibration in higher modes of slab in the light of its great effect on the radiation of sound.

A Case Study to Minimize Effect of Blasting Vibration and Noise on Animal Casualties (발파진동과 소음이 가축에 미치는 영향에 관한 사례연구)

  • 안명석;김종대;황소중
    • Journal of KSNVE
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    • v.11 no.1
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    • pp.104-110
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    • 2001
  • The demand of blasting work in civil engineering work is increasing because of the increasing social infra-structural construction work. The blasting method creates large benefit in regard to the economic aspect and shortening construction period. This method, however, has problems to be solved in respect to the blasting vibration and noise. Blasting vibration and noise have been studied by many workers, regarding to the impact on the structure and human body. This investigation is concerned on the affect of blasting vibration and noise on the animals which is relatively new. In general, animals have inferior mental capacity than human in hearing but have higher sensitivity on the vibration and noise due to blasting. The object of this study is to investigate an appropriate measurement of lessening damage on the animals by vibration and noise due to blasting.

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The Visualization of Vibration and Noise of The Rotary Compressor during One Cycle of Crank Shaft by use of Short Time Fourier Transform (STFT를 이용한 로터리 압축기 크랭크 1회전 동안의 실시간 진동소음의 가시화)

  • Ahn, Se-Jin;Jeong, Weui-Bong;Park, Jean-Hyung;Hwang, Seon-Woong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.428-433
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    • 2002
  • There have been many studies to visualize the vibration and noise of rotary compressor. Most of these studies assumed that the signal is stationary and the time-averaged signal is used for visualization. However, the noise and vibration signals generated during one cycle of crank shaft vary continuously. In this paper, the noise and vibration of rotary compressor which vary continuously are visualized by short time fourier transform method. The location of source and the transfer path of vibration and noise at arbitrary frequencies, which can not be visualized by averaged signal, can be visualized clearly.

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Vibration and noise control of slab using the multi-tuned mass damper (다중질량감쇠기를 이용한 슬래브의 진동 및 소음저감에 관한 연구)

  • Hwang, Jae-Seung;Kim, Hong-Jin;Kang, Kyung-Soo;Hong, Gun-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.659-664
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    • 2008
  • In this study, it is outlined that heavy weight floor impact noise induced by the vibration of slab can be reduced by multi tuned mass damper(MTMD) effectively. Substructure synthesis is utilized to develope analytical model of slab coupled with MTMD and acoustic power is introduced to evaluate the performance of noise control for simplicity. Numerical analysis is carried out to investigate the effect of the properties of MTMD on the vibration and noise control. Numerical analysis shows that mass ratio of MTMD is critical on the vibration and noise control of the slab and it is essential to reduce the vibration in higher modes of slab because it has a great effect on the radiation of sound.

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Research on the Noise and Vibration of Mechanical Equipments in Apartment Buildings (공동주택 설비장비의 소음.진동 실태조사)

  • Kim, Myung-Jun;Kim, Heung-Sik;Kim, Ha-Geun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.157-164
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    • 2000
  • A mechanical equipment room with various equipments may be the largest source of noise and vibration. Without sufficient consideration for noise and vibration control in the phase of designing, it causes some problems after completing construction or enormous cost necessary to correct the problems. Therefore, it is essential to consider the method of noise and vibration control, but the systematic guideline of noise and vibration is not provided yet. This study aims to investigate the actual condition of noise and vibration generated from mechanical equipments in apartment buildings, for providing the guideline of its control.

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A Study on Prediction and Evaluation of Noise and Vibration Using GIS (GIS를 이용한 소음진동의 예측 및 평가에 관한 연구)

  • Kim Tae-gu;Yoon Hee Kyung;Lee Sang Hyun;Park Min Soo
    • Journal of the Korean Society of Safety
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    • v.20 no.1 s.69
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    • pp.13-17
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    • 2005
  • This paper presents an information system of noise and vibration caused by people as a major source of the environmental problem in residential areas with which people are dissatisfied. Therefore, it is important to monitor the influence of noise and vibration in residential areas. Generally, Geographical Information Systems (GIS) play an important role in noise and vibration mapping. The purpose of this paper is to investigate noise and vibration effects in an urban area and develop a new information network in GIS. Noise and vibration measurements were carried out at a road randomly chosen near INJE University. The obtained values are graphically represented with GIS. Therefore, it is possible to predict noise and vibration in GIS when establishing effective urban plans.