• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.452-459
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• 1997

For computer aided design and construction of low noisy power plants, indoor and outdoor noise prediction program has been developed. The program utilizes the predefined data of noise sources and building materials and has the faculty to estimate the source level using the empirical formula in case of the measured data not being available. In the noise prediction, the mutual noise propagation between indoor and outdoor sites are considered. The outdoor noise source in the calculation of geometric divergence effects is modelled as the omni-directional finite line or planar source according to the source geometry and the receiving points. Outdoor noise prediction is carried out to consider the diffraction effect due to plant structures as well as the attenuation effect due to atmospheric absorption and soft ground. The results of indoor and outdoor noise prediction for a recently constructed diesel engine power plant show good agreement with the measured.

• 한국소음진동공학회논문집
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• 제21권7호
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• pp.609-614
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• 2011

The ship working environment of combat service support boat is much inferior to the ground working environment. For this reason, the crew of a combat service support boat suffer from an occupational disease such as hardness of hearing. Owing to its small size and low status, the improvement of its working and residential environment was occasionally ignored and its indoor noise was not fully investigated. In this study, for improving its residential environment indoor, the indoor noise of its shipboard compartments was analysed. These studies define the indoor noise level of combat service support boat is very high and some of indoor noise is exceeded the criteria for ship noise. Compared with marine police vessels, the indoor noise levels of marine police vessels are higher than the level of combat service support boat.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.423-428
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• 2008

The monitoring efficiency of the aircraft noise monitoring stations is decided to the reference noise level and the infringement of each monitoring stations. We are calculate the monitoring efficiency of three noise monitoring stations among twelve in the vicinity of Gimpo Int'l Airport. As a result, the monitoring efficiency shows that the noise monitoring stations #3,#5 and #6 are 14.3%, 18.5% and 29.3% respectively, #6 which is underneath the flight track is higher efficiency than another two stations.

• 한국소음진동공학회논문집
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• 제19권1호
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• pp.50-55
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• 2009

The monitoring efficiency of the aircraft noise monitoring stations is decided to the reference noise level and the infringement of each monitoring stations. We calcurates the monitoring efficiency of three noise monitoring station among twelve in the vicinity of Gimpo Int'l Airport. As a result, the monitoring efficiency shows that the noise monitoring stations No#3, No#5 and No#6 are 14.3%, 18.5% and 29.3% respectively, Among them No#6 staion looks higher efficiency than another two stations because of underneath the flight trackas.

• 소음진동
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• 제8권1호
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• pp.187-194
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• 1998

In order to predict the train noise propagation from a level railroad, this paper presents the model of train noise source and the prediction model based on the results by using the sound intensity method. The prediction model gives the effects of geometric attenuation, ground attenuation, and barrier attenuation of noise. There are several principal assumption in developing model: (a) the train noise is primarily rolling noise; (b) the rail head and wheels are in good condition; (c) the height of source is 10cm above track; (d) the directivity pattern of train noise sources is a dipole source. Calculated results based on this model are compared with available field data and good agreement has been obtained.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.618-626
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• 2011

Recent development of related technologies and efficient utilization of the entire country for the purpose of railway construction, and plans are being accelerated. the railway noise has been improved by increasing the high speed railway station, and accelerating the existing trains. Nord2000 which is an overseas noise prediction equation could not be applied directly to the domestic railway vehicles. So the specific vehicles in the Nordic countries which is a similar specification to domestic trains should be selected. Nord2000's accuracy was compared to Schall03, CRN's. Prediction of Ground impedance and Roughness class were carried out at different. In this paper, the result of selected vehicles for Nord2000 was as follows. S-1aX2 was for express trains, N-$^*2c$-3b was for Mugunghwa, S-Pass/wood was for Saemaul, N-4a was for freight trains, N-3a was for subway, the calculation time for Nord2000 took longer than others, in addition, Ground absorption was indispensable to calculate a noise map for Nord2000. As a result, CRN's prediction noise levels at Wonju-si was closest to the measurements. However, the predicted noise levels of Nord2000 was the most accurate.

• 한국소음진동공학회논문집
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• 제23권7호
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• pp.605-616
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• 2013

An important source of noise from railways is rolling noise caused by wheel and rail vibrations induced by acoustic roughness at the wheel-rail contact. In the present paper, characteristics of rail vibration and radiated sound power from concrete slab tracks for domestic high speed train(KTX) is investigated by means of a numerical method. The waveguide finite element and boundary element are combined and applied for this analysis. The concrete slab track is modelled simply with a rail and rail pad regarding the concrete slab as a rigid ground. The wave types which contribute significantly to the rail vibration and radiated noise are identified in terms of the mobility and decay rates. In addition, the effect of the rail pad stiffness on the radiated power is examined for two different rail pad stiffnesses.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.803-808
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• 2011

The shipboard working environment of navy vessel is very inferior to the ground working environment. For this reason, the crew of a navy vessel suffer from an occupational disease such as lumbar pain, hearing loss, etc. Although standard for navy vessel's environmental vibration is applied, the criterion of the environmental vibration is too high. So it doesn't help to improve habitability of crew. In this study, for improving its habitability of crew, the current vibration level of navy vessel was examined and the standard of navy vessel's environmental vibration was investigated.

• 한국소음진동공학회논문집
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• 제22권2호
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• pp.139-145
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• 2012

The shipboard working environment of navy vessel is very inferior to the ground working environment. For this reason, the crew of a navy vessel suffer from an occupational disease such as lumbar pain, hearing loss, etc. Although standard for navy vessel's environmental vibration is applied, the criterion of the environmental vibration is too high. So it doesn't help to improve habitability of crew. In this study, for improving its habitability of crew, the current vibration level of navy vessel was examined and the standard of navy vessel's environmental vibration was investigated.

• 소음진동
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• 제7권3호
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• pp.419-426
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• 1997

The psychological, physiological, and material effects of ground vibrations induced from railroad were surveyed with the magnitudes of vibration sensing using questionnaire on residents living near railroad. These magnitude of vibration sensing and effects were compared as rate or percent total based on double distances from railraod. Also overall effects of railraod vibrations were compared with vibration levels measured or predicted. The about 70% of residents living within 40m from railroad sense railroad vibration, 15% of residents are influenced phychologically. But physilogical and material effects disappeared beyond 40m.