• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.657-660
• /
• 2000

전력연구원은 원자로 내부에 적용하기 위한 소형경량의 수중로봇을 개발하기 위한 준비작업으로 자이로를 이용한 수중로봇 조향장치를 개발하고 있다 이장치는 자이로 3개를 조합한 모듈을 서보가 회전시켜 일정한 방향으로 서보의 회전속도에 비례하는 회전토크를 발생하도록 고안되었다 발생된 토크는 작용/반작용의 원리에 의해 서보가 부착되어있는 로봇본체에 작용한다. 이장치를 이용하면 수중로봇의 중심에서 Yaw와 Pitch를 제어할 수 있는 토크가 발생하고 좁은 공간에서 신속한 자세변환이 가능하다 본 고에서는 자이로 조향장치의 구조와 이론적 배경 및 시뮬레이션 결과를 소개한다.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.43-44
• /
• 2001

프레임에 그물감을 부착하여 구성되어 있는 가두리 시설은 파랑과 조류 등에 의해 유체력을 많이 받기 때문에, 만 입구 또는 외만에 설치하는 경우에는 작용 유체력에 의하여 이것을 계류하고 있는 계류삭이 절단되거나 고정용 닻이 끌리게 되며 프레임 끼리 서로 충돌함으로써 결국 구조물이 파손된다. 이와 같은 문제점을 해결하기 위해서는 파랑과 조류에 의해 발생되는 유체력에 충분히 견딜 수 있도록 시설물을 설계해야 한다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.197-198
• /
• 2001

일반적으로 해조류가 번무하고 있던 암초지대에서 무엇인가의 원인으로 해조류가 고사ㆍ소멸하고, 그 공간을 석회조류로 불리는 여러 종류의 산호말류 (coralline algae)이 점유하여 암반이 백색 또는 황색, 분홍색을 나타내는 현상을 ‘백화현상’ 이 라고 한다. 현재 추측되는 백화현상의 원인으로는 해양생태계 내에서의 환경변화 - 대기중 이산화탄소의 증가, 지구 온난화에 의한 수온상승, 그리고 연안역의 오염 -와 군집의 동태와 생물학적 작용-엽상형 해조류와 무절석회조류간의 경쟁과 성게를 포함한 초식동물의 초식작용, 질소, 인등의 결핍이 불러오는 빈(貧)영양화 - 에 의해 일어난다고 추측된다 (analysis.cheju.ac.kr.). (중략)

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.3
• /
• pp.308-316
• /
• 2010

Odontoblasts are anchorage dependent cells adhering to a substrate via cell adhesive molecules. Receptor ligands such as integrins bind to these proteins and are known to function as signal transduction molecules in a series of critical recognition events of cell-substratum. The aim of this study is to examine the interaction of odontoblast (MDPC-23 cell) with type I Col and the effect of TGF-${\beta}1$ and TNF-$\alpha$ on the expression of cell adhesion molecules. In this study, MDPC-23 cells adhered to type I Col dose-dependently. Immunofluorescence data demonstrated that integrin ${\alpha}1$, ${\alpha}2$ and CD44 were expressed on cell surface, and FAK and paxillin were localized in focal adhesion plaques in MDPC-23 cells adhesion to Col. Cytokine TGF-${\beta}1$ increased the adhesion of MDPC-23 cells to Col and the expression level of integrin ${\alpha}1$, 4{\alpha}2$ and chondroitin sulfate on MDPC-23 cells. RT-PCR data demonstrated that cytokine TGF-${\beta}1$ increased the amount of integrin ${\alpha}1$ mRNA in MDPC-23 cells. Therefore, MDPC-23 cells adhere to collagen type I Col and expressed a complex pattern of integrins and proteoglycans, including ${\alpha}1$, ${\alpha}2$, chondroitin sulfate and CD44 detected by immunoblotting and immunofluorescence assay. TGF-${\beta}1$ treatment enhanced the expression of adhesion molecules such as integrin ${\alpha}1$, ${\alpha}2$ and chondroitin sulfate.

• Journal of Korean Society of Steel Construction
• /
• v.14 no.2
• /
• pp.357-364
• /
• 2002

The study performed a series of flexural tests on Closed Cold-Formed Steel Sections for stud, joist, and roof truss. Results were compared with analytical values. Each 2.4-m long and 0.9-m wide specimen consisted of two steel beams set at 0.46 m interval. The steel beams were attached to the specimens using either plaster board or ply wood. Another specimens did not use any attachment material. Positive and negative bending tests were conducted to investigate the composite behavior, including the effects of plaster board or ply wood on the buckling behavior of steel beam. Full-scale roof truss tests were also performed to study the buckling behavior and failure mode of the truss members.

• Journal of Korean Association for Spatial Structures
• /
• v.5 no.3 s.17
• /
• pp.101-107
• /
• 2005

An analytic study on the bond stress between steel tube and concrete in concrete filled steel(CFT) tublar column is presented in this paper. Recently buildings need members which are enhanced durability and ductility. Concrete filled tublar column system is proposed as alternative plan. In this paper, ABAQUS/Standard Version 5.8 which is identified as usefulness for finite element analysis and has various element library is used. The variables in this study are the location and type of shear-connector. The modeling ell contact problem practiced by Contact Pair and Contact Pressure method. In the step of physical bond, it is practiced by Change friction option. After yielding of models, analytic results is less than that of experimental results.

• Tunnel and Underground Space
• /
• v.11 no.4
• /
• pp.339-343
• /
• 2001

Shield tunnel having circular section located in the soil or soft rock layer is liable to deform in such a way that its two diagonal diameters crossing each other expand and contract alternately during earthquakes. Based on this knowledge, the ground-tunnel interaction effect for this particular vibration mode is investigated. The ground surrounding a tunnel is assumed to be a homogeneous elastic medium. The bonded boundary condition on the ground-tunnel interface is considered. This suggests a firm bond between the ground and the tunnel lining. As Poisson's ratio and stiffness of the ground increases, the strain induced within the tunnel lining increases.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2012.11a
• /
• pp.140-143
• /
• 2012

사람간의 상호작용에서 손은 중요한 역할을 담당하고 있기 때문에, 사람과 컴퓨터 사이의 인터페이스에 관한 연구에서 역시 손을 이용한 자연스러운 상호작용은 중요한 화두 중 하나이다. 따라서 본 논문에서는 손 기반 인터페이스를 위한 손 모양 인식 방법을 제안한다. 제안하는 방법은 비전 기반의 방법을 이용하기 때문에 사용자의 몰입을 방해할 수 있는 마커 혹은 센서의 부착을 요구하지 않으며, 간단하지만 효과적인 방법을 사용함으로써 실시간 연산을 보장한다. 또한 사용자의 양 손을 추적하고 손의 모양을 인식함으로써, 보다 자연스러운 양손 기반의 상호작용을 제공한다.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.3 s.49
• /
• pp.113-123
• /
• 2006

An experimental investigation on the behavior of reinforced concrete coupling beams is presented. The test variables are the span-to-depth ratio, the ratio of flexural reinforcements and the ratio of shear rebars. The distribution of arch action and truss action which compose the mechanism of shear resistance is discussed. The increase of plastic deformation after yielding transforms the shear transfer by arch action into by truss action. This study proposes the deformation model for reinforced concrete coupling beams considering the bond slip of flexural reinforcement. The strain distribution model of shear reinforcements and flexural reinforcements based on test results is presented. The yielding of flexural reinforcements determines yielding states and the ultimate states of reinforced concrete coupling beam are defined as the ultimate compressive strain of struts and the degradation of compressive strength due to principal tensile strain of struts. The flexural-shear failure mechanism determines the ultimate state of RC coupling beams. It is expected that this model can be applied to displacement-based design methods.

• Journal of the Korean Society for Railway
• /
• v.12 no.5
• /
• pp.641-648
• /
• 2009

Concrete structures become more common in railway systems with an advancement of high speed train technologies. As the service life of concrete structures increases, structural strengthening for concrete structures may be necessary. There are several typical strengthening techniques using steel plate and fiber reinforced polymer (FRP) materials, which have their own inherent shortcomings. In order to enhance greater durability and resistance to fire and other environmental attacks, basalt fiber material attracts engineer's attention due to its characteristics. This study investigates bonding performance of basalt fiber sheet as a structural strengthening material. Experimental variables include bond width, length and number of layer. From the bonding tests, there were three different types of bonding failure modes: debonding, rupture and rip-off. Among the variables, bond width indicated more significant effect on bonding characteristics. In addition the bond length did not contribute to bond strength in proportion to the bond length. Hence this study evaluated effective bond length and effective bond strength. The effective bond strength was compared to those suggested by other researches which used different types of FRP strengthening materials such as carbon FRP.