• 한국공작기계학회논문집
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• 제17권3호
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• pp.128-132
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• 2008

The noise levels and individual employee noise exposure levels within a factory will determine the need for hearing conservation program. The difficulty in not having an effective hearing conservation program is the risk of hearing loss that employees may sustain. In the last few years the claims for hearing loss compensation have grown due to class action litigation brought against the employer and companies that have equipment in the factory alleged to have caused hearing loss. The Blower in the factory generates the noise of 98.3dB(A) in the frequency range of 2,000Hz, which may cause occupational hearing loss. By designing close type enclosures which are made of absorption material, about 24.4dB(A) reduction has been in the factory. It is demonstrated that this kind of enclosures can be effectively used to reduce the noise in the factory.

• 소음진동
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• 제7권1호
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• pp.107-116
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• 1997

Friction between stone and saw of stone cutting machine generates the noise of 96-104 dB in the frequency range of 2kHz-8kHz, which may cause occupational hearing loss. By designing enclosures which are made of transparent acryl, PVC panel and absorption materials, about 15 dB noise reduction has been achieved in the stone cutting factory. It is demonstrated that this kind of enclosures can be effectively used to reduce the noise in the stone cutting factory.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.102-106
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• 2006

Community noise has been serious social issues in Korea. The community noise concerns on traffic, industrial and apartment complex noise. In industrial noise, construction, factory sectors are included. This paper summerizes the final report prepared for MOE in 2005 by authors. The new policy will be enforced beginning in 2006 with 5 year schedule. Details on the policy will be demonstrated at the presentation.

• 한국멀티미디어학회논문지
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• 제10권8호
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• pp.1004-1016
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• 2007

본 논문에서는 기준신호를 획득하기 어려운 환경에서 환경소음이 정상적인 특성을 가질 경우 음성을 향상시킬 수 있는 가중치 갱신제어 적응소음제거기를 제안하였다. 일반적인 적응소음제거기의 경우 소음만의 기준신호를 획득하여야 한다. 그러나 다수의 기기에 의한 복합적인 소음과 작업자에 의한 음성이 혼합되는 공장 환경에서는 소음발생원들로 부터 순수한 소음신호를 획득하기가 어렵다. 따라서 기준신호를 이용할 수 없기 때문에 이러한 환경에서는 기존의 적응잡음제거기를 사용하기가 어렵다. 제안한 방법에서는 입력신호를 임의의 상수로 하고 기준신호에 마이크로폰의 신호를 입력한다. 그런 다음 음성이 없는 구간에서 적응필터의 가중치를 갱신하여 소음을 제거하고 음성이 발생한 구간에서는 가중치를 고정하여 소음이 제거된 변형 음성신호를 획득한다. 그리고 변형 음성신호를 복원 필터링하여 음성신호를 출력한다. 이것은 다수의 공장소음이 정상적이고 짧은 대화구간에서 소음이 변하지 않는 점을 고려하였다. 실험의 결과 제안한 소음제거기가 공장소음을 효과적으로 제거할 수 있었고 신호 대 잡음비 면에서도 우수함을 확인하였다.

• 한국안전학회지
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• 제22권1호
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• pp.30-35
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• 2007

With the rapid industrialization and civilization development, noise has become a major problem in cities and is a very serious issue for the environment. Noise induced in a factory has a bad influenced on operation efficiency, accuracy and detail of work. The purpose of this paper is to develop a new noise evaluation software for predicting acoustic condition including noise properties during the design of a factory. Majority of commercial softwares for this purpose have been developed in foreign countries and they are quite expensive and hard to use. A new home-made software tool has been developed in the present work, which aimed at providing a more user-friendly environment. The tool developed in this work consists of four major part; the prediction and evaluation of noise in system design, database design, noise analysis development and 3D graphic modeling. The outcome of present work is expected to provide domestic users with a more user-friendly and economic acoustic design tool.

• 대한안전경영과학회지
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• 제17권4호
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• pp.97-103
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• 2015

The people who are in the noise factory are difficult to hear and recognize about fire and to evacuate quickly when a fire occurs. This study was conducted to analyze workplace's background noise of 31 factories in Incheon and to know the workplace noise level comparing to fire alarm sound level. The measured average noise level was 96.8dB(A). Noise level of measured result was exceeded as 6.8dB(A) comparing to NFSC (National Fire Safety Code) noise level of 90dB. NFPA suggests that when background noise exceeds 85dB or more than that, other methods should be considered to know alarm sound. Also fire alarm sound should exceed more than 15dB(A) comparing to background noise level. Therefore it was concluded that the design of the fire alarm systems should not be applied to the workplace without considering background noise and it needs to be improved with regulations and the systems.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4659-4664
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• 2014

산업 현장에서 발생하는 소음은 작업자의 건강과 작업 효율에도 영향을 줄 뿐 아니라, 주변의 주거지역의 소음 민원의 원인이 된다. 본 논문에서는 중소규모 공장에서 많이 사용되는 송풍기에서 발생하는 소음을 3차원 공간에서 능동소음제어기(ANC)를 이용하여 저감하는 기술 개발을 위한 기초 연구를 수행하였다. 이를 위해 ANC의 설정과 결과 데이터를 용이하게 파악할 수 있는 시뮬레이터 프로그램을 Labview를 이용하여 작성하여 음압레벨, 스펙트럼, 등가소음도 등의 데이터를 비교하였다. 소음 데이터는 현재 중소규모 공장에서 운전 중인 터보팬 송풍기에서 발생하는 소음을 기기 주변 17개의 위치에서 녹음하여 사용하였다. 모의실험 결과 17 지점 모두 500Hz 이하 저주파 대역에서 파워 스펙트럼이 최대 40dB 줄었으며 등가소음레벨이 평균 12.6dB 감쇄되는 결과를 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.967-970
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• 1988

This paper deals with automatic system of acoustic noise detection for realization of factory automation. The existing inspection process of failure products has mostly been executed in hand by rich-experienced workers. It is difficult to accomplish effectively or systematically the failure test of products owing to the diversality of ill-conditions. But the problem about it must be solved in viewpoint of cost down and factory automation in addition to the reliability of products. The necessity of automatic inspection system to inspect automatically undesirable acoustic noise of products which is one of the kinds of failure is suggested, and the procedure to develope it and the function of each system components are explained briefly.

• 한국안전학회지
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• 제15권3호
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• pp.88-95
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• 2000

The level of noise produced by machinery and its arrangement insides a factory is indicated to be a maximum of 96.1 dB(A). The maximum level of noise from a commoner's house outside the factory is shown to be 62.9 dB(A), which exceeds 60 dB(A), the permitted limit of noise level in a time period of day. us study has predicted the level of noise reduction according to a step by step prevention plan by considering the characteristics of the causes of noise, the permitted limit of noise levels, problems and economical efficiency attendant upon the noise prevention measures. Establishing target levels of noise each of the three steps of the noise prevention plan. The predicted level of noise at the place of a commoner's house in accordance with the first step is 50.0 - 59.0 dB(A), and can satisfy the permitted limit of noise in a time period of the day. In taking prevention measures for the second step, the noise level is 50.7 - 53.6 dB(A) which is less than 55 dB(A) in a time period of the evening, the permitted limit of noise in a time period of night., and it can meet 47.4 - 50.3 dB(A) in the third step.

• 수산해양기술연구
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• 제35권1호
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• pp.41-49
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• 1999

This paper describes to analyze the underwater ambient noise and biological noise of cultivating fishes in the fish farm cages at the seawater Tongyong-kun, KyongNam and lake of Chungju, Chech'on, ChungBuk from 10 to 19 Oct. 1997, in order to find out the characteristics of these noises. The results obtained were as follows; (1) The ambient noise around the fish farm cages at lake of Chungju was 10~200Hz frequency range, 70~105dB spectrum level. The central frequency was 50~70Hz, changing of ambient noise was getting bigger than 10~200Hz in 200Hz~2kKz frequency by wind, water current. (2) The frequency of noise source around the fish farm cage at the seawater of Tongyong-kun was 20~200Hz, spectrum level was 80~100dB while feed factory was working around the fish farm cage. When feed factory did not work, noise source was 10~600Hz frequency range, 70~90dB spectrum level. It was 10dB less than that of while feed factory was working, and then the central frequency was 70Hz. (3) The vessel noise of excursion ship had changed largely at 100dB spectrum level in 10~500Hz frequency band, and the fishing boat had 20Hz~2kHz frequency range. (4) The biological noise in the fish farm cage at lake of Chungju, which was feeding of Cyprinus carpio, 2was 10~30Hz frequency, 70~104dB spectrum level. The central frequency was 75Hz. The biological noises in the fish farm cage at the seawater of Tongyong-kun, which were feeding and swimming noise, had very different spectrum pattern by species, and the frequency band was 10~800Hz.