• Structural Engineering and Mechanics
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• 제26권3호
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• pp.277-295
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• 2007

3-D wall panels are used in construction of exterior and interior bearing and non-load bearing walls and floors of building of all types of construction. Fast construction, thermal insulation, reduced labor expense and weight saving are the most well pronounced advantage of such precast system. When the structural performance is concerned, the main disadvantage of 3D panel, when used as floor slab, is their brittleness in flexure. The current study focuses on upgrading ductility and load carrying capacity of 3D slabs in two different ways; using additional tension reinforcement, and inserting a longitudinal concentrated beam. The research is carried on both experimentally and numerically. The structural performance in terms of load carrying capacity and flexural ductility are discussed in details. The obtained results could give better understanding and design consideration of such prefabricated system.

• 한국화재소방학회논문지
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• 제26권2호
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• pp.105-111
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• 2012

본 연구에서는 건축외장재로 많이 사용되고 있는 알루미늄복합패널의 일반재와 난연재에 대한 화재성능 비교분석에 관해 연구하였다. 실험방법은 중소형 실험장치 중 콘칼로리미터 실험과 SBI(Single Burning Item)을 적용하여 분석하였다. 그 결과 콘칼로리미터 실험에서 최대 열방출률이 일반 알루미늄복합패널은 $1,293kW/m^2$($75kW/m^2$), 난연 알루미늄복합패널은 $70kW/m^2$($75kW/m^2$)가 측정되었다. SBI 실험에서 화재확산지수가 일반 알루미늄복합패널은 약 743W/s이고 난연 알루미늄복합패널은 약 97 W/s의 값이 측정되었다. 이는 일반 알루미늄복합패널의 경우 건축물 내장재의 성능기준에서 난연기준에도 훨씬 못 미치고, 플래쉬 오버(Flash over) 발생 가능성을 나타내었다. 따라서 이러한 알루미늄복합패널의 화재 위험성을 평가하여 외장재로서 사용 시 갖춰야 할 조건에 대한 기준마련이 시급히 요구된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.322-325
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• 2007

Dent resistance is an important characteristic to avoid damage on automotive outer panels. From a practical point of view, dents can be caused in a number of ways. Considering doors as an example, denting can occur from stone impacts or from the careless opening of an adjacently parked vehicle door. Denting can occur where the door surface is smooth and may not have sufficient curvature to resist dent. These exterior body parts are designed to improve dent resistance using a combination of work hardening and bake hardening. In brief, dent is affected by the shape of the parts and the material properties such as yield strength, strain and thickness. In this work, forming of door outer panel is investigated by Taguchi method. Main parameters are yield strength, thickness, blank size, blank holding force and so on. For the given value of design parameters, forming analysis of the thirty six cases are carried out according to L18 orthogonal array. After comparing the performance by simple conversion of simulation results into dent resistance, the final suggestion of the forming parameters is verified for the best improvement of dent resistance.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.225-229
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• 2011

The aluminum composite panel are widely used for the external materials of high rise building because of well insulation of heat and sound and improved Constructability. However, the polyethylene in main material of the aluminum composite panel shows weakness in thermal and fire resistances. For this reason, flame is spread more quickly when the fire break out. Therefore, the potentiality of fire spread to the exterior wall is high due to difficulty of early extinguishment and effect of external air. In this study, numerical investigation was performed by using FDS program for flame spread characteristics with various external air velocity and direction in ten-story building with the aluminum composite external materials. As a result, the flame spread velocity is 0.134m/s and it takes 224 seconds for flames to spread to the 10th floor without external air velocity. however, the flame spread velocity decreases 40% and it takes 348 seconds for flames to spread to the 10th floor when external air velocity is 2.5 m/s. and air direction is little effect compared to air velocity.

• 소성∙가공
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• 제16권4호
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• pp.254-259
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• 2007

Dent resistance is an important characteristic to avoid damage on automotive outer panels. From a practical point of view, dents can be caused in a number of ways. Considering doors as an example, denting can occur from stone impacts or from the careless opening of an adjacently parked vehicle door. Denting can occur where the door surface is smooth and may not have sufficient curvature to resist dent. These exterior body parts are designed to improve dent resistance using a combination of work hardening and bake hardening. In brief, dent is affected by the shape of the parts and the material properties such as yield strength, strain and thickness. In this work, forming of door outer panel is investigated by Taguchi method. Main parameters are yield strength, thickness, blank size, blank holding force and so on. For the given value of design parameters, forming analysis of the eighteen cases are carried out according to L18 orthogonal array. After comparing the performance by simple conversion of simulation results into dent resistance, the final suggestion of the forming parameters is verified for the optimal improvement of dent resistance.

• 한국광학회지
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• 제19권4호
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• pp.310-314
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• 2008

PDP(plasma display panel)를 비롯한 대형 디스플레이는 외부의 광이 디스플레이 내부로 입사될 경우 화질 및 명암이 저하된다. 이 문제를 해결하기 위해서 최근 관련 산업체에서는 $1\;m^2$급의 대형 투명필름 위에 수십${\sim}$수백 ${\mu}m$ 수준의 미세 패턴을 새겨서 외부 광을 차단하는 contrast 향상 필름을 개발 중이다. 이 필름이 디스플레이에 적용되려면 가장 중요한 것이 패턴의 균일도 및 이물 여부이다. 하지만 기존의 검사장비로는 $1\;m^2$급의 대형 광학 필름을 $100\;{\mu}m$ 수준의 분해능으로 짧은 시간 내에 측정할 수 없다. 본 연구에 서는 이것이 가능한 검사장비를 제안, 구축하며 실험을 통해 평가한다.

• 한국안전학회지
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• 제30권6호
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• pp.40-47
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• 2015

In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length ${\times}$ 50 cm height ${\times}$ 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in $218^{\circ}C{\sim}995^{\circ}C$ at 30 seconds and $501^{\circ}C{\sim}1078^{\circ}C$ at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of $501^{\circ}C$ was shown at 300 seconds and marble inner wall showed the following lowest temperature of $900^{\circ}C$. Temperature rising over $1000^{\circ}C$ was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

• 한국화재소방학회논문지
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• 제29권6호
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• pp.84-90
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• 2015

복합자재(샌드위치패널)는 불연성재료인 양면 철판 또는 이와 유사한 재료와 불연성이 아닌 재료인 심재로 구성된다. 단열재를 가연성 재료로 사용하는 샌드위치패널은 화재 시 철판 내부로 화염이 확산되어 외부에서 진화가 어렵고 화염의 확산이 빠르게 진행되어 건물의 붕괴를 야기할 수 있다. 현행 건축법에 의해 샌드위치패널은 건축물의 용도 및 규모에 따라 난연성능을 확보하도록 하고 있다. 본 연구에서는 일부 외벽에 적용되는 화재확산방지구조를 복합자재에 적용하여 실제 규모의 화재시험을 통해 그 효과를 측정하였으며 향후 복합자재에서도 화재확산방지구조의 적용을 통해 복합자재 건축물의 화재안전 확보 가능성을 제시하였다.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.29-38
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• 1997

The effect and control of wood property of reconstituted composite panels for improved board properties by wood-waste materials and development of combination method for heterogeneous materials have been of interest to the wood science researchers. The purpose of this study is to consider the properties in relation to hot pressing conditions and to develope the optimum hot pressing condition with waste wood and waste tire for the manufacturing of composite boards. The study of composite boards for recycling of wood and waste tire is nothing up to the present. Physical and mechanical properties such as specific gravity, moisture content, swelling coefficient, modulus of rupture and modulus of elasticity in bending test were studied. The condition of 3-stage press time for the lowest moisture content of composite board was $4{\rightarrow}3{\rightarrow}3$ minutes. Specific gravity of composite panels was affected mainly by the amount of rubber chip. Because of the low rigidity and high elasticity in rubber chip, it is considered the composite panel was adequate material in the place of compression load, but not bending load. Therefore, it was concluded that a use of rubber-based wood composite panel is proper to the interior materials such as floor a room than exterior materials. From the test results, the most optimum hot pressing conditions were $4{\rightarrow}3{\rightarrow}3$ minutes for 3-stage press time and $45{\rightarrow}20{\rightarrow}5kg/cm^2$ for 3-stage press pressure. The rubber-based wood composite panel was very excellent in elasticity by combination of rubber chip in comparison with existing other wood-based materials. Therefore, it was considered that rubber-based wood composites can be applicable to every interior materials such as floor a room and will be expected to effective reuse and recycle of waste tires and wood-waste materials, and will be contribute to protection of environment pollution in earth.

• 한국CDE학회논문집
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• 제19권2호
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• pp.91-102
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• 2014

The outer surface of an irregular structure contains panels with two-directional curvature called NURBS. To construct these forms of exterior materials, complex geometric surface should be divided into forms and sizes that can be manufactured and constructed. Because the bigger the curvatures of these divided exterior panel, the more expensive the construction costs, these complex two-directional curvatures should go through optimal process of reinterpretation to minimize the curved surfaces with complex two-directional curvatures. Yet, to gain higher ground in technological competition in the field of irregular structure construction, companies do not share know-how that they obtained. Accordingly, small construction and design companies have trouble calculating even rough estimate and cannot adjust expected construction cost based on comparison of design alternatives. Given this situation, this study conducted the research that can support decision-making in the design stage of the construction and provide basic material for optimal range to reduce manufacturing cost by the minimizing the distorted plane of the irregular structure.