• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.249-250
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• 2018

To control the floor noise generated in the apartment building, a method of reinforcing the floor at the floor is applied. However, since existing buildings are difficult to reinforce upper generations, the ceilings of lower generations should be reinforced. The purpose of this study is to analyze the reduction effect by measuring the impact noise after reinforcing the floor soundproofing material on the ceiling of the existing building. In order to ensure the economical efficiency and flame retardancy of the products used as building interior materials, the existing polyurethane foam was impregnated with mineral to prepare test specimens and attached to the concrete slab surface. As a result, it was shown that heavy impact sound can reduce 2dB~5dB and light impact sound can reduce 4~8dB.

• 한국철도학회논문집
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• 제9권1호
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• pp.43-49
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• 2006

We have evaluated the structural integrity of a sandwich composite train roof structure that can be a lightweight, cost saving solution to large structural components for rail vehicles in design stages. The sandwich composite train roof structure was 11.45 meters long and 1.76 meters wide. The finite element analysis was used to calculate the stresses, deflections and natural frequencies of the sandwich composite train roof against the weight of air-conditioned system. The 3D sandwich finite element model was introduced to examine the structural behavior of the hollow aluminum extrusion frames joined to both sides of the sandwich composite train roof. The results shown that the structural performance of the sandwich composite train roof under loading conditions specified is satisfaction and the use of aluminum reinforced frame and aluminum honeycomb core is beneficial with regard to weight saving and structural performance in comparison with steel reinforced frame and polyurethane foam core. Also, we have manufactured prototype of sandwich composite train roof structure on the basis of analysis results.

• Journal of Advanced Research in Ocean Engineering
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• 제1권4호
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• pp.211-226
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• 2015

Membrane type Mark III cargo containment system (CCS) is considered in this study to investigate its strength capability under applied loads due to liquefied natural gas (LNG) cargo. A rectangular plated structure supported by inner hull structure is exemplified from Mark III CCS according to classification society's guidance and it is assumed as multi-layered structure by stacking plywood, triplex, reinforced polyurethane (PU) foam and series of mastic upon inner hull structure. Commercially available general purpose finite element analysis package is used to have reliable FE models of Mark III CCS plate. The FE models and anisotropic failure criteria such as maximum stress, Hoffman, Hill, Tsai-Wu and Hashin taking into account the direction dependent material properties of Mark III CCS plate components and their material properties considering a wide variation of temperature due to the nature of LNG together form the strength analysis procedure of Mark III CCS plate. Strength capability of Mark III CCS plate is understood by its initial failure and post-initial failure states. Results are represented in terms of failure loads and locations when initial failure and post-initial failures are occurred respectively. From the results the basic design information of Mark III CCS plate is given.

• 보존과학연구
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• 통권26호
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• pp.127-139
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• 2005

We have conserved the sword with round pommel with a tri-ring which was excavated from No. 1 tomb of the Duckcheon-ri at the Gyeongju and requested from Jungang Research Center of the Cultural Heritage. When this artifact excavated, it was pressed flat state because of the influence of earth pressure and stuck to a gravel and soil laid scattered on the wooden coffin. If the artifacts is handled without plan, it can be damaged, therefore that sword was collected together with soil using the Polyurethane foam. After the artifact which had a weak specific and was collected using a this method can be safetly collected as below; First, we made the supporter of article ordered using a silicon and gypsum. The silicon can conserve the weak point of the artifact because it has a flexible and smooth properties and the gypsum can adhere closely to the artifact because it has a little expansion and shrinking but a hard and fluid characters. Consequently, gypsum is a good complement to the weak point of the silicon. Second, During a remove gauze and a reinforcing agent from the surface of a artifact which was reinforced using a acetone steam method. The acetone steam method can be supplement to a dangerous problem of acetonedircet method because this can be damaged in a surface of the artifact.

• 한국안전학회지
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• 제29권1호
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• pp.21-24
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• 2014

In this study, we have investigated the maximum smoke density and the initial stage smoke density in order to see the characteristics of smoke release of the architectural surface materials and the architectural adhesives, using smoke density chamber. As a result of the study, polyurethane foam showed the highest smoke density index, 206.55 within 10 min. In the case of the other samples, reinforced styrofoam was followed as 39.90, general styrofoam 33.73, and glass fiber 5.40, respectively. In the intial stage of a fire, it is forecasted actually to give hardship at the clear visibility. In the case of architectural adhesives, the highest ranking was those for windows and doors 509.64, stone 275.63, wood 232.25, tile 18.65, and styrofoam 6.44 were followed, respectively. This result is an early research to show characteristics of smoke release through experiment. However, it is meaningful that this study can be used as a basic for further study on architectural fire hazard prediction.

• 한국전산구조공학회논문집
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• 제24권4호
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• pp.429-438
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• 2011

본 논문에서는 Membrane형 LNG선의 구성 요소를 대상으로 단열창의 열적 분포를 알아보기 위해 극저온 상태에서부터 온도 별로 각 소재의 열적 물성치인 열전도도(thermal conductivity)를 실험을 통해서 알아보았다. 극저온 상태인 $-163^{\circ}C$의 온도상태로 유지되어야 하는 LNG선 화물탱크는 단열재료로 하여금 열을 차단하기 위해 많은 연구가 되어야 하는데 특히 여러 재료로 구성되어 있는 단열 화물창(CCS: Cargo containment system)은 열적 물성치가 온도에 따라 각각 어떠한 값을 가지는 것이 주요 관심대상이고, 이를 통해 전체 LNG 단열 화물창이 어떤 열적 분포를 가지는 것에 대한 연구가 필요하다. 실험을 통해 얻은 물성치를 가지고 전체 화물창의 온도분포를 정적 열해석을 통해 알아보았다. 또한 외부의 충격에 의해 LNG가 누수되었을때 2차 방벽 특히 hull 부분에서는 누수량에 대해서 어떠한 온도분포와 열적 안전성에 대해서 알아보았다.

• 대한기계학회논문집A
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• 제34권3호
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• pp.307-313
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• 2010

본 논문에서는 지역난방에 사용되는 이형관인 벤드(bend)의 형상설계에 대한 연구를 수행하였다. 지역난방관은 강관(내부)과 폴리우레탄 보온재(중앙부) 그리고 고밀도폴리에틸렌 외관(외부)의 3개의 중공관으로 구성되며 일반적으로 $10{\sim}120^{\circ}C$ 온도범위의 물이 $16kgf/cm^2$의 내압을 가지면서 수송된다. 이에 따라 작동 중 발생하는 반복적인 열적-기계적 하중을 지탱할 수 있어야 한다. 보통 지역난방관의 벤드부에는 폼패드라고 부르는 신축흡수재가 덧씌워지는데 이 폼패드의 노후에 따른 문제가 종종 발생한다. 본 논문에서는 벤드부에서의 폼패드 노후 문제를 경감시키기 위한 대안으로 폼패드를 없앤 이중보온관의 형상 설계를 제안하였다. 제안된 설계는 벤드부 강관에 전단고리(shear ring)를 적용하는 방법으로 이때 전단고리의 최적치수는 다구찌 방법과 유한요소법을 적용하여 접근하였다. 그 결과로 전단고리의 두께와 높이, 개수 순으로 최적화 효과가 있음을 확언하였다.