• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.758-759
• /
• 2011

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.19 no.9
• /
• pp.928-934
• /
• 2009

Underwater impulsive sound such as underwater blasting noise, piling noise and stone breaking hammer affects marine animal hearing response and organs. This study describes the characteristics of various impulsive noise from waterfront construction site and their effect on fish. Time constant, peak pressure, energy and SEL(sound exposure level) of four different underwater impulsive sounds are quantified. Auditory and non-auditory tissue damage ranges are derived by comparing their quantities to the exposure criteria for fish. Damage ranges of auditory tissue and non-auditory tissue of underwater boring blast of 150 kg of charge, are about 100 m and 300 m, respectively. Other three impulsive sounds also gives damage effects but less than that of underwater boring blast.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.703-706
• /
• 2001

Currently domestic criteria for the aircraft noise is being adapted WECPNL(weighted equivalent continuous perceived noise level), while internationally preferred method is which is originated from $L_{eq}$ and can evaluate even environmental noise. WECPNL used in domestic as a evaluation method is only for the aircraft noise. It is, therefore, not adequate for the evaluation of residents' injury, moreover, it is very difficult to measure the aircraft noise with WECPNL due to the complicated calculating procedures as long as automatic measuring system is not used. Accordingly, this study aims to propose alternative evaluation method for the aircraft noise. To achieve this purpose, the data measured by automatic measuring system were gathered and calculated with three evaluation methods： WECPNL, $L_{eq}$ and $L_{dn}$ and the results calculated from different methods were compared and analyzed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1994.04a
• /
• pp.70-75
• /
• 1994

소음진동은 최근 사회적 인식이 변함에 따라 환경관련 민원 중에서 가장 많은 건수의 민원이 발생되는 요소로서 제저업체, 건설업체등의 기업 뿐만 아니라 국토개발, 도시개발을 담당하는 정부 기관 등에서 각종 업무를 수행하는데 중요한 고려대상이 되고 있다. 소음진동이 충분히 저감되지 않은 가전제품은 소비자들에게 외면당하고 민원이 발생된 건설 공사현장에서의 피해 보상금은 기업이 원가부담으로 작용되며 그 사업주체가 정부일 경우는 행정업무 처리에 지장을 초래하게 된다. 소음진동 문제를 해결하는데 가장 우선적으로 필요한 요소는 소음진동 허용기준을 적절히 산정하는 것이다. 소음진동은 발생원인이 매우 다양하며 소음진동에 노출되는 사람(혹은 건축물, 정밀기계 등)의 상대적인 위치(사회 문화적인)에 따라 피해 정도가 다르기 때문에 각국의 정부나 각종 사회단체, 기업은 독특한 국민성, 지역성, 사회개발 정도 등에 따라 적절한 허용기준을 제시하고 있다. 소음진동 문제를 해결해야 할 담당자들은 이러한 모든 여건을 고려하여 현재 상황에서 가장 적절한 허용기준을 설정하고 소음진동 저감 대책을 수립하여야 한다. 본 연구에서는 설계자나 공장관리자, 건설 현장의 관리자들이 소음진동 문제에 직면 했을 때 신속히 적절한 허용기준을 산정한 후 소음진동 대책을 수립할 수 있도록 국내의 주요 소음진동 허용기준을 수립하여 데이타베이스화 하고 이를 PC통신으로 이용가능하게 하는 NVC-DS(Noise and Vibration Criteria-Database System)을 개발하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.4
• /
• pp.35-41
• /
• 1998

The workplace noise environment is composed of three basic elements : manufacturing (in a generic sense) facilities, office areas, and the community around the facility. Work must be done by all employees , and this involves communication within a variety of locations within the facility ; areas may be extremely noisy, moderately noisy, or quiet, such as an office. At the same time, the facility should not be annoying to the community. In this paper, the workplace environmental noise of office areas in power plant are studied. Turbine generator in power plant generates the noise of 90∼95 dB(A) in the frequency range of 1 kHz, which may cause occupational hearing loss. By abatement method which are made of isolation material and distance damping effect, about 29.5 dB(A) reduction has been obtained in office areas of the Power Plant . But, the workplace environmental noise of office areas in the power plant is not suited to office's purpose.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.5-8
• /
• 2008

Apartment housing is a widely-spread type in Korean housing market. Nevertheless, it has caused serious problems such as traditional community corruption, unsafe structure, defects and litigation from noise. Noise, especially in concrete structure for apartment housing, is hardly controlled in proper to prevent sound transmission between upper and lower families with existing system, In foreign countries, there are floating floor systems to enhance the noise control performance in multi-family housing. Therefore, this study aims to analyze subjective responses on sound characteristics in residential buildings. We analyzed the residential response and the quantities of measured data from environmental noise. The results of this study will be useful to provide guideline to make policy of environmental noise and criteria.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.402-405
• /
• 2006

The diffuser noise of HVAC(heating ventilating and air-conditioning) uses dB(A) or NC as a indoor noise criteria that ASHRAE represents, and there is no specific guide line for application. According to the previous study, there are some problems like that even though the sound level of sound source is same, the NC shows different values, which makes the noise rating confused. This problem is caused by the frequency characteristics of sound source and its sound level. Therefore, appropriate evaluation method should be considered based on the subjective responses. This study aims to analyze the physical parameters appropriate for the evaluation of HVAC diffuser noise. To achieve this, recording of sound sources, calculation of physical parameters and psycho-acoustic experiment were carried out and the results were derived from the correlation analysis between physical parameters and subjective evaluatio

• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.185-191
• /
• 1999

This paper deals with a method to predict the noise level inside metro electric cars running a single-line tunnel at the speed of 80km per hour using ray tracing method, a kind of ray acoustics generally used for a high-frequency and air-born noise analysis. The interior of the car including a under-frame, seats, side doors, end doors, door-pockets, side panels, end panel, a roof panel and so on is modeled. And in order to describe the noise power coming inside, artificial noise sources are designated using sound transmission loss data of each section measured from simple tests and external noise level. The noise level inside the car is calculated and its properties are investigated. The results satisfy the criteria on noise level inside the car.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.960-963
• /
• 2003

Sound intensity method is well known as a visualization technique of sound field and sound propagation in noise control. Sound intensity is a vector quantity that describes the magnitude and the direction of net flow of acoustic energy at a given position. The current measuring method is expensive and difficult to identify the noise source exactly. In this paper, we have studied the noise source identification and the characteristics of noise source of rotary compressor for air conditioner using complex sound intensity method. The new method for instantaneous sound intensity is also proposed and it is useful for transient state and steady state. The criteria of these state, select auto correlation coefficient. The advantage, simplicity and economic attribution of this method are verified by analyzing the characteristics of noise source with instantaneous sound intensity compared to mean sound intensity.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.2
• /
• pp.138-143
• /
• 2007