• Journal of Environmental Science International
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• v.16 no.7
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• pp.771-778
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• 2007

This study has been conducted to achieve the following objectives: First, in order to understand the horizontal propagation and attenuation characteristics for the railroad traffic noise, we selected areas within 100 meters away from the railroad and then selected Saemaul-ho and Mugoongwha-ho as the subjects for our experiment. In this way, we analyzed the horizontal propagation and attenuation characteristics for the traffic noise occurring in diversified areas. Second, in order to understand the vertical propagation and attenuation characteristics for the railroad traffic noise, we measured and analyzed the distributional characteristics of vertical sound pressure levels on each floor of multi-storied apartment buildings according to changes of traffic load and types, and the existence or nonexistence of soundproof walls. For the case of the railroad traffic noise, we also selected Samaul-ho and Mugoongwha-ho as the subjects for our experiment, and we measured and analyzed the different noise levels on each floor of multi-storied apartment buildings from the soundproof wall. The results of Horizontal propagation and attenuation characteristics for the railroad traffic noise are as follows: In cases of the flat land, cutting land, and bridge area, as distance increases, the sound pressure level steadily decreases. The sound pressure level for the bridge area is higher than that of the flat land with a measurement of $5.5{\sim}10.2\;dB(A)$. Vertical propagation and attenuation characteristics for the railroad traffic noise are as follows: The amount of sound pressure level decrease is $14.2{\sim}14.8\;dB(A)$ for Samaul-ho and $13.5{\sim}14.3\;dB(A)$ for Mugoongwha-ho when measuring the vertical sound pressure levels at heights lower than 4.5 m, which indicates a fairly large decrease. At 6 m, the amount of decrease is 8.6 dB(A) for Samaul-ho and 8.2 dB(A) for Mugoongwha-ho, which indicates a small decrease.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1291-1297
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• 2009

The purpose of this study was to establish structural bone noise analysing method for apartments building floor with Structural-Acoustic coupling analysis. Nowadays, noise through floor is recognized as important problem with the consequence that noise isolation technique is studied in the various fields of industry. From among noise factors, resonance sound is main reason for floor's solid noise. therefore, In this study, evaluation method for composite material slab is established and that a case study is suggested with it.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1350-1354
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• 2000

철도 소음에 의한 환경문제가 증가하고 있으나 방음대책으로는 아직까지 방음벽을 철도 연변에 설치하는 것인데 이러한 방음벽은 주위 경관과의 부조화와 열차승객의 시아방해 등으로 높이에 제한을 받는다. 높이를 높이지 않고도 저감효과를 얻을 수 있는 방음벽과 상단형상의 개발이 중요한 연구과제로 대두되고 있다. 본 논문에서는 철도연변에 설치되는 방음벽의 종류별로 삽입손실을 ISO 10847에 근거하여 측정하였으며 그 결과를 상호 비교 분석 평가하였다.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.123-128
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• 2003

The purpose of this study is to analyze the efficiency of the noise reduction measure in the downtown construction. For decades, the life level rise in Korea makes the environmental issues developed the important issues. Specially the noise problems have become the hot issue in the building construction. This study covers the efficiency of the measures, which is used in the construction field to reduce the noise. The case was obtained by Korean E＆C company in 2003. It is used as important sources. The results of this study are as follows; the reduction efficiency is higher than that of the old measure. But more efforts are needed to comfort nearby residents.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.662-667
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• 1994

This paper presents the design and construction details of a soundproof enclosure for housing 20 KVA diesel generator-set. As the generator had to be installed close to the hospital building, it was desirable to reduce the transmission of noise by housing the generator in such an enclosure. The diesel engine being an air cooled one, it was essential to supply fresh air into the enclosure for its cooling. Forced inflow of air is provided through an inlet duct located in such a way that the incoming fresh air is thrown close to the inlet of cooling fan of the engine. The high velocity air stream, which heats up while passing over the engine head, escapes to the atmosphere through a rectangular outlet duct with enlarges inlet that receives hot air from the engine. The air ducts were designed specially and have been provided with acoustic lining for sound absorption. The masonary enclosure has been provided with double glazed fixed windows and double doors. The exhaust pipe of the engine fitted with a muffler has been taken out through the enclosure wall facing away from the hospital. Acoustic performance studies conducted in terms of attenuation provided by the enclosure at different frequencies have also been presented and discussed. The noise control measures adopted for building the sound-proof enclosure have been found to be quite effective as the noise levels inside the hospital building are now within the acceptable limits.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.658-663
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• 2011

The purpose of this study is to develop an air-passing soundproofing panel with more improved structure to reduce the $CO_2$ emission and installation cost. To reduce the emission of $CO_2$ ; it is suggested to choose low $CO_2$ emission material relative to the aluminum and to reduce the materials by developing a specially designed air-passing soundproofing panel structure. First of all, we performed the flow analysis to predict the wind pressure according to the open angle of the air-passing soundproofing panel and the noise level analysis at the receiver point. To verify the simulation, a prototype of the soundproofing panel was made. The flow test in the wind tunnel and load test were performed. The economic evaluation for the installation of the air-passing soundproofing panel was performed and specifications of the installation was prepared. As the results of this research, it was verified that the wind load was reduced about 40% to that of the conventional one at 25m/s wind speed in the wind tunnel test. By applying the 4m span soundproofing wall with air-passing soundproofing panel and under the cost of 250 thousand $won/m^2$ instead of the conventional 2m span panel, the installation cost will always be lowered than the conventional one in the combination of (60:40~50:50) conventional to air-passing soundproofing panel from the economic evaluation. The 20% reduction of $CO_2$ was found by changing the 50% of aluminum soundproof panel to air-passing soundproofing panel.

• KIEAE Journal
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• v.16 no.1
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• pp.37-45
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• 2016

Purpose: According to the characteristic of hanok public building, Planning criterion of structure, technology, efficiency, design is needed which can includes various type of new-hanok type public buildings. In this paper, we collect expert opinions to be used as a basis for developing models of New-hanok type Public Buildings. Method: This study was conducted in Research Study and expert surveys. The Part of reviewing Study looked at conception of new-hanok type public buildings model development and overview planning criterion set briefly. Expert surveys were targeted to professors and architects who are related in new-hanok type public buildings model development research. Result: In this study, we suggest improvement direction about planning criterion of new-hanok type public buildings model development based on opinions collected by expert surveys. In conclusion, first, In concept and legal status, it is necessary to adjust clearly than the term and legal status of new-hanok type. Second, various applicability is needed by using new materials and new construction method at the part of planning elements. Third, 'composed structure-convergence type' and 'composed structure-juxtaposed type' should be clearly classified or combined at the part of Setting of type. Forth, improvement on heat insulation, soundproof, waterproof efficiency is demanded to roof, wall, window systems. Fifth, arranging revitalization plan is important.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.699-706
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• 2016

This study aimed to propose the necessity and system establishment of noise reduction facility via evaluating noise level exposed by the radiographer due to MRI scan. Noise measurements were carried out using at S general hospital in Daejeon using 1.5 Tesla MRI (7 exams) and 3.0 Tesla MRI (16 exams), while using SC-804 noise meter. The measurement distance was from the soundproof door of the MRI room to the radiographer which measured 100cm, and the measurement height, the height to the radiographer's ears when working, 100cm. The noise measured for each exam was an average of three measures per exam which observed the noise occurring in each sequence recorded every 20 seconds. As the results, the maximum of noise exposed by the radiographer is 73.3 dB(A), which is MRCP by the 3.0 Tesla device, and also the maximum of average noise is 66.9(3.1) dB(A), which is Myelogram by the 3.0 Tesla device. Average noise by each device is 61.9(4.1) dB(A) by the 3.0 Tesla device and 52.0(3.1) dB(A) by the 1.5 Tesla device, which comes to the result that the 3.0 Tesla MRI device is about 10 dB(A) degree higher(p <0.001). The noise level exposed by the radiographer does not affect auditory acuity, but the level is able to incur a non auditory effect. The reflect sound can be removed by installing curtains in the rear wall of MRI control room in order to reduce the noises, but, first of all, An institutional system is needed in order to prevent noise.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.2
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• pp.120-125
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• 2015

With rapid urbanization, the volume of traffic in urban area has been significantly increased. This in turn led to problem which can be described as Road Traffic Noise. Currently, to alleviate the road traffic noise damage, a demand for installation of soundproofing walls is rising. Among different shapes of soundproof walls being installed, the reflection-type acoustical insulation panel is highly drawing attentions of residents due to the fact that it does not obstruct their field of vision in contrast with the opaque acoustical insulation panel. On the other hand, improving the soundproofing wall of the reflection-type acoustical insulation barrier panel needs to be focused on since it has a possibility to cause a secondary damage by reflected sounds. Therefore, in this research, study has been carried out to improve the forms in order to minimize travelling of reflected sounds through changing the frontal surface shape and geometrical shape of the reflection-type soundproofing panel. A result from comparison between the normal reflection-type soundproofing panel and the improved soundproofing panel, with reduction effects in the noise reflection, showed that the curved type of soundproofing panel has an impact on reducing the noise up to 1.5 dB. Furthermore, from the research conducted, it appears that the increase and decrease in the reflected sounds can be changeable depending on various design factors. Thus, it turns out that the study shows a potential possibility to develop a reduction technology of the reflected sounds pertaining to overall condition on the soundproofing walls.

• Korean Journal of Environment and Ecology
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• v.18 no.1
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• pp.92-102
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• 2004

In this study, landscape changes were examined by periods through the analysis of visual quantity on the landscape components of national road including the mountains, the sky, road pavements, street trees, paddy fields and dry fields, billboard, telegraph pole, building, structure, slope, guard fence, soundproof wall, and median strip etc. For this, subject national road in suburb arreas was selected to grasp its landscape characteristics, and divisional criteria of landscape type of the national road were suggested to look into the trend of landscape changes by periods. Findings of this study are as follows：1.Divisional criteria of landscape type of the national road include location and geometry, structure, land use, perspective, and surrounding buildings of the national road. 2.The highest visual quantity was found in road pavements by periods among landscape components of the national road. It was found that this result has a thread of connection with previous study emphasizing the importance of road geometry as one of landscape components, and road geometry shall be regarded as a visually significant component in analyzing and evaluating landscape of the national road. 3.Most distinguished factors of landscape changes of the national road by periods were median strip(F＝33.296) and street tree(F＝32.881), and then the sky(F＝24.735) and mountain(F＝23.477) showed similar level of statistically significant difference. However, statistically significance difference was not found in buildings and structures. 4.It was shown that natural elements decreased gradually but structural landscape made of artificial elements became the main in construction of the national road. This result implies that although the scenic and ecological soundness is recognized in construction of the national road, it is not out of the limitation of functionalities that is, access and mobility.