• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.170-174
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• 2002

In this study, the material characterization and the dynamic behavior of 3D orthogonal woven composite materials has been studied under transverse central low-velocity impact condition by means of the micromechanical model using finite elements. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is stacked in x-y-z direction repeatedly. First, the mechanical properties of 3D orthogonal woven composites are obtained by means of virtual experiment using full scale Finite Element Analysis based on the DNS concepts, and the computed elastic properties are validated by comparison to available experimental results[9]. Second, using the implementation of this validated micromechanical model, 3D transient finite-element analysis is performed considering contact and impact, and the impact behavior of 3D orthogonal woven composite is investigated. A comparison study will be carried out in terms of energy absorption capabilities.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.53-56
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• 2005

In this study, the material characterization and the dynamic behavior of 3D orthogonal woven composite materials has been studied under transverse central low-velocity impact condition by means of the micromechanical model using finite elements. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is stacked in x-y-z direction repeatedly. First, the mechanical properties of 3D orthogonal woven composites arc obtained by means of virtual experiment using full scale Finite Element Analysis based on the DNS concepts, and the computed elastic properties arc validated by comparison to available experimental results. Second, using the implementation of this validated micromechanical model, 3D transient finite-clement analysis is performed considering contact and impact, and the impact behavior of 3D orthogonal woven composite is investigated. A comparison study with the homogenized model will be carried out in terms of global and local behaviors.

• Journal of computational fluids engineering
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• v.2 no.1
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• pp.21-28
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• 1997

This paper presents a two-dimensional horizontal implicit model to general circulation in estuaries and coastal seas. The model is developed in non-orthogonal curvilinear coordinates system, using the Interpolating Matrix Method (IMM), in combination with a technique of multi-domain. In the propose model, the Saint-Venant equations are solved by a splitting-up technique, in the successive steps; convection, diffusion and wave propagation. The ability of the proposed model to deal with full scale nature is illustrated by the interpretation of a dye-tracing experiment in the Gironde estuary.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.265-268
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• 1997

In the recent day, fatigue life prediction techniques play a major role in the design of components in the ground vehicle industry. Full scale durability testing in the laboratory is an essential of any fatigue life evaluation of components or structures of the automotwe vehicle. Component testing is part~cularly important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, multi-axial road simulator is used to carry out the fatigue test and the vibration test. In this paper, the algorithm and software to realize the real road profile are developed. The validity of the software are verified by applying the belgian road, the city road, the highway, and the gravel road. The results of the above experiment show that the real road profiles are realized well after loth iteration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.951-956
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• 2008

The study is to develop a foundation design for a railway vehicle simulator using a scaled model. Although a scaled simulator is limited to manipulate the dynamics of a full-size railway vehicle, it has been known to have an advantage, since a scaled model could provide the fundamental dynamic behavior within a limited space of a laboratory facility and with a low operation cost while an experiment is conducted. This study is to propose a design strategy for a simulator so that a small scaled roller rig could be fabricated in a laboratory based on the design philosophy. The data obtained from the scale model is also experimentally investigated in conjunction with appropriate non-dimensional analysis so that the output results should be interpreted to the railway vehicle.

• Structural Engineering and Mechanics
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• v.61 no.3
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• pp.427-436
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• 2017

This paper presents an experimental and analytical investigation on the behavior of a U-shaped girder subjected to operation, cracking and ultimate loads. A full-scale destructive test was conducted on a U-shaped girder to study the cracking process, load-carrying capacity, failure mechanism and load-deformation relationships. Accordingly, the tested U-shaped girder was modeled using ANSYS and a non-linear element analysis was conducted. The investigation shows that the U-shaped girder meets the specified requirements of vertical stiffness, cracking and ultimate load capacity. Unfavorable torsional effect is tolerable during operation. However, compared with box girders, the U-shaped girder has a more transverse mechanical effect and longitudinal cracks are apt to occur in the bottom slab.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.739-744
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• 2009

The filter has long been used in purification processes for indoor air quality. To determine the deodorization effect of several filter materials in a full-scale air-handling system, the present study has been carried out using a wind tunnel equipped with a heat exchanger and various filter materials, such as commercial fabric, activated carbon(AC) and silver nano-particles attached to activated carbon(Ag-AC). The experiment was conducted using an odor substance with ammonia, acetaldehyde, acetic acid. The results obtained indicate that odor substance is substantially decreased on the moisture condensation on the surface of the heat exchanger. The fabric filter has no effect for removal of odor substances. The deodorization efficiency is found to be approximately 7% in the AC filter, while the deodorization efficiency is increased up to 10% using the Ag-AC filter.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.349-352
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• 2012

본 연구에서는 주택화재가 발생할 경우, 건축용 외장재로부터 발생하는 유해성 가스를 분석하고자 주택화재재연실험을 수행하였다. 실험 방법으로는 스티로폼, 우레탄폼, 글라스울 소재의 샌드위치 패널을 대상으로 KS F 2271 규격을 이용한 실험용 생쥐의 생체반응을 실험하였으며, NES 713을 이용한 독성가스에 대한 분석을 실시하였다. 샌드위치패널에서 발생하는 대표적인 유해성 가스는 시안화수소와 일산화탄소이며, 그 중에서 가장 유독한 것은 시안화수소로서 2차 세계대전 당시 유대인 학살에 사용된 독가스인데 시안화수소를 사람이 흡인한 경우 750ppm 이상이면 즉사하며, 375ppm 이상이면 30분 내에 사망하는 것으로 알려져 있다.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.2
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• pp.7-12
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• 2016

This study have an objective to suggest basic data and measured result of heating performance on water-water type horizontal geothermal heat pump which is based on heating and cooling load calculation result of small residential house. The average temperature during measured periods is $9.4^{\circ}C$ on primary EWT and is $7.6^{\circ}C$ on primary LWT. The temperature difference shows $1.8^{\circ}C$ as average temperature. Because the average outdoor temperature of peak is lager than on December and than on January, the temperature difference between EWT and LWT is bigger that on January than that on December. The system COP is 3.62.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1998.11a
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• pp.29-39
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• 1998

복도는 사무실용 건물, 호텔 등 공중이용 건물에서 중요한 피난경로의 일부이다. 화재로 복도에 연기가 확산되면 그 온도, 연층의 높이, 유해물질의 농도 등에 따라 피난에 심각한 장애를 가져올 수 있다. 본 연구는 이러한 복도에서의 연기의 확산 및 유동에 관하여 연구하기 위하여 길이 40m의 복도에서 pool fire로부터의 연기 유동에 관한 실제크기의 실험과 수치해석을 수행하였다. 화재실과 그에 접해있는 긴 복도가 있는 실험장치에 직경 15, 20, 30cm의 가솔린 pool을 화재실 중앙에서 점화 시켰다. 연기의 온도 및 이동을 측정하기 위해 전장 중앙선을 따라 열전대를 설치하였고 연층의 두께를 측정하기 위하여 수직방향으로 세곳에 열전대가 부착된 수직봉을 설치하였다. 아르곤 레이저 sheet 과 비디오 카메라를 이용해 연기의 유동을 가시화 하였다.