• Journal of Korean Tunnelling and Underground Space Association
• /
• v.8 no.1
• /
• pp.41-51
• /
• 2006

This paper concerns the effect of lining interface adherence on the lining's load carrying capacity. A series of reduced scale laboratory tests and finite element anlayses were carried out with the aim of gaining insight into the effect of shotcrete lining adherence on the load carrying capacity of double shell lining. The results indicated among other things that the load carrying capacity of a double shell tunnel is significantly affected by the adherence between layers. Also revealed was that for cases with low lining layer adherence stress concentration may occur due to relative movement between the lining layers with this trend being more pronounced with increasing tunnel cover depth. Practical implications from the results of this study are discussed in great detail.

• Journal of Sericultural and Entomological Science
• /
• v.44 no.1
• /
• pp.37-41
• /
• 2002

The attaching treatment of sericin onto polyester fiber was attempted to improve its sanitary properties. Generally, sericin, a gummy material covering the outer layer of silk filament, is subjected to be removed during degumming process of silk textile process. For this study, sericin particle dissolved within the degumming waste water could be collected by sedimentation of polyaluminium chloride. It was revealed that sericin particle were attached onto the surface of polyester fiber evenly by treatment of glutaraldehyde, a crosslinking agent. A frictional static charge of the treated polyester fabric could be improved, while its hygroscopic property was little changed.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.2 no.3
• /
• pp.36-41
• /
• 2011

This study proposes a experimental method to evaluate bonding strength of FRPs used for retrofitting concrete structures. Specimens are designed so that debonding failure of FRPs can be induced from reinforced concrete beams retrofitted with two layers of carbon and glass FRPs. And three-point loading tests are performed to see if debonding failure with proper debonding strength is observed from the specimens. The test results show that the tested beams are failed due to debonding of FRPs, therefore, the proposed test method is capable of evaluating debonding strength of FRPs using relatively small normal strength concrete beams.

• Proceedings of the IEEK Conference
• /
• 2003.07c
• /
• pp.2541-2544
• /
• 2003

새로운 원리에 의한 원격 거리 및 각도측정 시스템［1］［2］(이하 TS, Total Station)을 개발하였다. 본 시스템은 마이크로 터널링 공법의 굴진기의 후미 또는 임의의 기준점에 원격으로 점멸할 수 있는 십자형의 발광체를 부착하고, 추진관에 고정시킨 상하좌우 각도측정 및 비접촉식 레이저 거리측정기가 부착된 무인 원격 제어장치에 의하여 십자형 발광체의 중심을 자동으로 검출한다. 또한. 회전각과 CCD 라인 스캔 센서의 조합에 의하여 각도를 정밀하게 원격 측정하게 된다. 한편 본 시스템을 이용하면 마이크로 터널링 공법에 의한 추진관내의 측정 가능한 범위를 연결하는 위치에 복수의 TS를 배치하여 서로의 위치를 자동으로 계측하고 그들 데이터를 컴퓨터에 의하여 계산함으로써, 맨홀의 임의의 기준점으로부터 굴진기의 현재 좌표를 신속하고 정확하게 계산할 수 있다.

• Solar Energy
• /
• v.10 no.1
• /
• pp.31-37
• /
• 1990

An experimental study for the flow in an axisymmetric cavity of rectangular tube was performed. The pressure and heat transfer coefficient along the side and opposite-walls of the cavity were measured. The cavity length was varied from 80mm to infinity during the experiment. As the result of this study, it was found that as the length of cavity increased beyond the reattachment point, the heat transfer coefficient decreased. It was also found that the mean heat transfer coefficient became maximum near the reattachment point.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.51-52
• /
• 2010

The effect of bond strength of longitudinal reinforcing bars on shear strength of reinforced concrete beams is investigated from the view point of arch and truss actions. Stress fields with bond allow us identify possible failure modes including bond failure of a deep beam as well as a slender beam. The slope angle of diagonal compression fields is interpreted as balanced failures of two components involved for shear transfer.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.11a
• /
• pp.551-555
• /
• 2004

본 연구는 건설교통기술혁신 사업의 일환으로 '국가기준점의 관리 및 위치정보서비스 제공을 위한 전자표지석 개발' 과제에 관한 연구내용 및 결과를 중심으로 하고 있으며, 주 내용은 2차 년도 연구에서 수행한 TOA(Time Of Arrive) 방식을 적용한 전자표지석 개발에 관한 것이다. 본 연구의 궁극적인 목적은 국가기준점을 효율적으로 관리하기 위한 새로운 방안을 제시하는 것으로, 기준점의 현황을 실시간 모니터링하고 기준점의 위치파악을 용이하게 할 수 있는 시스템을 연구하는 것이다. 이를 위해 기준점의 현황을 모니터링 가능하도록 기준점의 움직임을 파악할 수 있는 센서를 부착하였고, 편리한 기준점 위치파악을 위하여 TOA(Time Of Arrive) 방식을 적용한 전자표지석의 설계 및 시제품을 제작하였다. 연구결과를 기준점 관리에 활용하기 위한 시제품을 개발하였다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2003.10a
• /
• pp.55-60
• /
• 2003

본 연구는 건설교통기술혁신 사업의 일환으로 "국가기준점의 관리 및 위치정보서비스 제공을 위한 전자표지석개발" 과제에 관한 연구내용 및 결과를 중심으로 하고 있으며, 주 내용은 1차년도 연구에서 수행한 전자표지석 개발에 관한 것이다. 국가기준점의 가장 중요한 기능이 측량을 수행하기 위하여 기준이 되는 정확한 위치 데이터를 제공하는 것이다. 이러한 중요성을 감안하여 기준점의 관리 및 보호에 관한 법적인 규제가 마련되어 있으나 현실적으로는 관리에 어려움이 많은 실정이다. 본 연구에서는 중요한 국가기준점을 관리하는데 있어 효율적인 방안을 도출하는 것을 목적으로 하고 있으며, 세부적으로 전자표지석 시스템을 개발하여 기준점 관리에 적용하기 위하여 연구를 수행하였다. 전파를 이용하여 기준점의 현황을 모니터링 가능하도록 기준점의 움직임을 파악할수 있는 센서를 부착한 전자표지석을 설계 및 시제품을 제작하였으며, 테스트 결과 목적했던 성과를 확인할 수 있었다. 향후 보완연구가 완료된다면 기준점 관리에 있어 실제 적용 가능한 연구결과를 얻을 수 있을 것이다.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.5
• /
• pp.391-407
• /
• 1987

To understand the effects of the cooling water system of the power plant on the succession of sessile zoobenthos, a series of experiments were carried out at the cooling water system of Samchonpo Power Plant from Hay 1985 to May 1986. The lowest species diversity of the zoobenthos was observed at the discharge canal. This is probably caused by both increased velocity and temperature of circulating water. It is also noticeable that species composition of the zoobenthos, to a certain degree, was affected due to the impingement of meroplankton during the entrainment process. While the number of species attached on the experimental substrata installed in the thermally altered area is smaller than that in the intake canal, the biomass is increased as the increased temperature eliminates some species and in turn stimulates reproduction and growth of the others. It is interesting that relatively high similarity exists between the summer communities in the intake canal and the spring communities in the thermally altered area, and the same relationship is also found between the fall communities in the intake canal and the winter communities in the thermally altered area. Ecological index curves of the zoobenthos of the intake canal follows the fluctuation pattern of the thermally altered area in one or two months of elapsed time, probably due to temperature increase by the inflow of heated water discharged from the power plant.