• Journal of the KSME
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• v.35 no.10
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• pp.886-895
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• 1995

근래들어 도시의 집중화와 고밀도화, 교통량의 증대 등 사회구조의 급격한 변화로 각종 소음원 들이 증가하고 있으며 소음에 대한 일반인의 관심도 점차 높아지고 있다. 건물의 경우 한정된 공간에서 거주자의 생활을 보다 쾌적하고 편리하게 하기 위해서 각종 설비들이 증가되고, 이들 설비들은 대용량화하는 추세에 있다. 건물내 공간의 기능을 능률적으로 유지하기 위해 설치된 각종 장비(공기조화기, 펌프, cooling tower, 보일러, 냉동기 \ulcorner 발전기 등)에서 발생하는 소음이 직접 실내로 투과되거나 이들이 발생하는 진동이 건물 구조체로 전달되어 실내소음을 야기시키는 경우가 많다. 따라서, 건물을 설계할 때는 실별 용도에 따라 허용소음도를 결정한후 이러한 실내 소음환경을 달성하기 위해 각종 조처를 강구하게 되는데, 이 글에서는 이러한 건물의 실내 소 음도 영향 평가의 하나로 특정 건물의 예를 들어 소음도 계산과 소음의 원인 및 대책에 관해 기술하고자 한다.

• The Journal of the Acoustical Society of Korea
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• v.34 no.5
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• pp.385-393
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• 2015

The speed of train has rapidly been increased in accordance with the developed railway technology. Nowadays, high-speed trains were introduced which has the speed faster than 400 km/h. In Korea, a lots of efforts were undertaken to increase the speed of train faster than 350 km/h, however noise and vibration are still the main problems to solve for realization of the high-speed train. In the case of operation speed faster than 350 km/h, it can be easily presumed that the noise and vibration damages could be increased in the train stations which are close to the passing railway tracks. Thus, the noise in the five different types of high-speed train stations were analyzed including stations built on the ground, underground, under rail, and two types on rail. The present paper predicts noises inside the stations depending on the speed of the passing trains and analyze the noise comparing with noise criteria (NC). Sound insulation performance of each part of buildings was calculated using the transmission noise formula and computer modeling, Finally, a series of processes were introduced to satisfy the aural environment with the optimum interior noise criteria by changing interior finishing materials.

• The Journal of the Acoustical Society of Korea
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• v.8 no.1
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• pp.59-66
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• 1989

This study aims to provide the basic data useful in assessing indoor-noise and designing sound devices in office buildings of HVAC system. The measurements of HVAC noise were carried out in office room and mechanical room. The performance of absorptive chamber and side branch was also estimated in the office buildings which have HVAC noise problems. The results of experiments show that the NR value of indoor HVAC noise is rather higher than that of ISO recommendations at the frequencies below 500Hz. In addition, the results indicated that the absorptive chamber attenuates noise over broad band frequencies and side branch reduces noise at the special resonant frequency.

• Journal of the Korean Society for Railway
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• v.4 no.1
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• pp.9-15
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• 2001

It is required that the indoor-noise level of KHST (Korean High Speed Train) should be lower than 66 dB(A) at 300 km/h. In this study, the indoor-noise level of KHST has been predicted to determine the maximum allowable sound power levels of major noise sources. It is found that the indoor-noise requirements for KHST can be met by increasing the transmission losses of the floor and side-wall structures as well as by lowering the sound power levels of the major noise sources.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.7
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• pp.650-656
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• 2011

The noise inside a naval vessel is very important in considering the need for hearing protection, improving the working environment and maintaining good communications for crews living on board a naval vessel. The indoor noise of a ship usually is specified by the A-weighted sound pressure level, but other evaluating parameters are required to reflect human senses more effectively. This paper uses additional noise indices related to room acoustics, such as NR(noise rating), NC(noise criterion), RC(room criterion), PSIL(preferred speech interference level) and loudness level to evaluate the noise inside cabins on a naval vessel. Using these psychological noise indices, allowable limit of noise level in cabins is suggested through psycho-acoustic evaluation for the noise in cabins.

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

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.369-374
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• 2016

Cooling towers have been installed on rooftops or outside of buildings and widely applied to control the indoor temperature in residential areas and buildings. However, the noise and vibration resulting from their operation may cause problems in adjacent buildings. The purpose of this study is to measure the noise and vibration of an industrial cooling tower located adjacent to industrial plants and to investigate its influence on the surroundings according to an authorized evaluation standard. Further, in order to measure the effect of the vibration of the tower on the precision equipment inside the plant, an experiment is conducted to measure the vibration of the ground in the plant and the targeted precision equipment. The measurement results indicate that the noise in the cooling tower is 4 to 9 dB(A) higher than the maximum level defined in the standard of 68dB(A). The effect of the vibration of the tower on the precision equipment is comparatively minimal, because that in the supporting frame of the building is weaker than that on the floor where the precision equipment is located. The vibration of the floor on.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.5-12
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• 2015

Since blasting noise is impact noise, it will give a sudden shock to the human. In the case, such as the blast vibration, it has given aging buildings and livestock great damage to move the vibration along ground in nearby regions. In this study, the influence of the blasting generated during excavation was analyzed for effects on regional. A couple of field and laboratory surveys about geological were carried out to figure out the geological ratio in the study-performed area. Blast vibration noise was compared to the domestic and abroad case studies and each of the institutions permissible standards established the most appropriate criteria in site condition. The vibration velocity of blasting vibration exploits the values which were measured from test blasting on the ground in order to examine blasting effect. Considering the blasting point as the shortest distance from safety facilities (farms, private houses, etc.), the examination of the influence range, which was derived from the vibration velocity of blasting vibration, was performed to figure out how the point affected the safety facilities. Three-dimensional numerical analysis was performed a time history analysis in order to analyze the behavior of the structure for a dynamic blast load, which was determined in three directions of the blast vibration value. The results of three-dimensional numerical analysis and the blasting effect of blasting vibration estimation equation blasting vibration of impact circle with accompanying test blasting were compared. And the analysis confirmed similar results figures.