• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.837-843
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• 1999

A common hydraulic jack using brdige retrofit has a problem of increasing cost and time of construction to construct additionally temporary bent or concrete bracket, in case of insufficiency work space and release hydraulic pressure. To solve the problem, this technique is developed to alternate the bridge bearing in adequate inspection condition. After control maximum lift-height and minimum lift-force of no damage to super structure, the constructive technique is to alternate and repair the bridge bearing using the wedge jack with bridge bearing ability that is no release hydraulic pressure stopper, and able to reuse separable cylinder.

• 대한조선학회논문집
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• 제45권5호
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• pp.477-486
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• 2008

Numerical analysis for slamming impact phenomena has been carried out when 2-dimensional wedge shaped structure with finite deadrise angles enter the free surface by using a commertial CFD code, FLUENT. Fluid is assumed incompressible and entry speed of the structure is kept constant. Geo-reconstruct scheme (or PLIC-VOF scheme) is used for the tracking of the deforming free surface. User defined function of 6 degrees of freedom motion and moving dynamic mesh option are used for the expression of the downward motion of the structure and deforming of unstructured meshes adjacent to the structure. The magnitude and the location of impact pressure and the total drag force which is the summation of pressures distributed at the bottom of the structure are analyzed. Results of the analysis show good agreement with the results of similarity solution, asymptotic solution and the solution of BEM.

• 대한조선학회논문집
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• 제34권3호
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• pp.70-75
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• 1997

본 연구는 선박을 이용한 핫코일 화물의 안전하고 효과적인 운송 방법에 관하여 다루고 있다. 기하학적으로 불안정한 화물인 핫코일을 양측에서 쐐기로 지지함으로써 안전성을 지켜주는 카세트(cassette)를 활용한 자동 선적/하역 시스템이 효율적이고 타산성이 있는 것으로 간주되고 있다. 카세트 위의 핫코일의 안전 및 나아가서 전체 운반선의 안전은 카세트의 지지경사각에 의해 직접적인 영향을 받는다. 카세트 경사각의 최적설계를 위하여 핫코일과 카세트간의 상대운동을 허용하지 않는 구속조건하에서 핫코일-카세트 화물의 동역학 모델이 개발되었다. 파랑중 운반선의 운동에 기인되어 핫코일에 작용하는 관성력의 합력과 카세트 경사면 반력 사이의 힘의 평형 조건식이 유도되었으며, 그에 따라서 수치시뮬레이션 프로그램이 개발되었다. 수치 시뮬레이션에 의하여 핫코일의 동안전성과 카세트 구조 강도를 고려한 최적의 카세트 경사각은 약 37도로 선정되었다. 설계된 카세트 경사각의 성능은 축소 벤치 테스트를 동하여 검토 및 입증되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.19-24
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• 1994

Four types of horizontal joint were tested to investigate the difference with regards to the compressive behavior and strength. These include wedge-type joints (i)with and (ii)without transverse reinforcement against splitting failure of the panel concrete, and wedge-type joints (iii)with different widths of joint concrete (6cm vs 8cm) and (iv)closed platform joint. It was shown that the compressive strength of wedge-type joint is about 10% higher than that of closed-type (platform) joint. But the effect of transverse reinforcement and joint concrete widths on the strength of the joints turned out be negligible. Also, the moduli of elasticity in panel and joint are compared and the equivalent moduli of the whole wall are derived.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.8-18
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• 2010

According to the needs of change to hybrid, fuel cell and electric vehicle, and to the increasing demand for safety and eco-friendliness, the necessity of Electro-Mechanical Brake(EMB) is being increased. But, one of the most important problems for realizing EMB to the practical use is that the required motor power for braking is too high. So the high braking efficient EMB is required. In recent years, the Electronic Wedge Brake(EWB) is noticeable for the high braking efficiency. In this research, we examine the improvable matter of the recent published EWB, and we propose the improved mechanism and the cost effective control method using this mechanism. And we test these feasibility by experiment and discuss these meaning and effect.

• Structural Engineering and Mechanics
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• 제18권4호
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• pp.475-491
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• 2004

Anchorage devices play an important role in post-tensioned bridge structures since they must sustain heavy loads in order to permit the transfer of the prestressing force to the structure. In external prestressing, the situation is even more critical since the anchorage mechanisms, with the deviators, are the only links between the structure and the tendons throughout the service life of the structure. The behaviour of anchorage devise may be studied by using the finite element method. To do so, each component of the anchorage must be adequately represented in order to approximate the anchor mechanism as accurately as possible. In particular, the modelling of the jaw/tendon device may be carried out using the real geometry of these two components with an appropriate constitutive contact law or by replacing these components by a single equivalent. This paper presents the numerical study of a mono-strand anchorage device. The results of a comparison between two different representations of the jaw/tendon device, either as two distinct components or as a single equivalent, will be examined. In the double-component setup, the influence of the wedge configuration composing the jaw, and the influence of lubrication of the anchor, will be assessed.

• 한국추진공학회지
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• 제10권4호
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• pp.47-53
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• 2006

본 논문에서는 탄소-페놀 복합재로 제조된 로켓 노즐 내열부품의 고온에서의 거동을 3차원 축대칭 유한요소 모델을 사용하여 해석하였다. 실제 작동 조건을 사용하여 카울 영역의 적층링을 해석한 결과 층각도, 축방향 치수, 경계조건은 적층링 내부의 응력 분포에 큰 영향을 주는 것으로 확인되었다. 특히 링과 링 사이의 접합부분에서 모서리 탈락 현상의 전조 현상인 층간분리가 발생한다. 분리현상 이후에는 층각도 방향 전단응력과 축방향 압축응력에 의해 탈락 현상이 발생하는 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.537-542
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• 2005

It was proposed that Ru(II)[(1,10-phenanthroline)$_2$dipyrido[3,2-a:2',3'-c]phenazine ([Ru(phen)$_2$DPPZ]$^{2+}$)complexes and 4',6-diamidino-2-phenylindole (DAPI) simultaneously bind to poly[d(A-T)$_2$] (Biophysics. J. 2003, 85, 3865). Förster type resonance energy transfer from excited DAPI to [Ru(phen)2DPPZ]$^{2+}$ complexes was observed. In this study, we synthesized $\Delta$- and $\wedge$-[Ru(phenanthroline)$_2$dipyrido[3,2-a:2’3’c]6-azaphenazine] ([Ru(phen)$_2$DPAPZ]$^{2+}$) at which the DNA intercalating ligand DPPZ was replaced and we studied its binding properties to poly[d(A-T)$_2$] in the presence and absence of DAPI using polarized spectroscopy and fluorescence techniques. All the spectroscopic properties of the [Ru(phen)$_2$DPAPZ]$^{2+}$-poly[d(A-T)$_2$] complex were the same in the presence and absence of DAPI that blocks the minor groove of polynucleotide, suggesting both $\Delta$- and $\wedge$-[Ru(phen)$_2$DPAPZ]$^{2+}$ complexes are located at the major groove of poly[d(A-T)2]. On the other hand, in contrast with [Ru(phen)$_2$DPPZ]$^{2+}$, both $\Delta$- and $\wedge$-[Ru(phen)$_2$DPAPZ]$^{2+}$ exhibited almost twice the efficiency in the fluorescence quenching of DAPI that binds at the minor groove of poly[d(A-T)$_2$]. This observation indicates that the efficiency of the Förster type resonance energy transfer can be controlled by a small change in the chemical structure of the intercalated ligand.

• 대한두개안면성형외과학회지
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• 제21권1호
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• pp.49-52
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• 2020

The specialized structure of the upper eyelid ensures complete closure of the eye and eyeball sealing. An upper eyelid injury can cause various symptoms associated with eyeball trauma, not just scar formation or eyelid deformity. In this report, we describe a case of lagophthalmos observed after wound repair in a patient with a crushing injury caused by a grinder. Several surgical techniques are used to treat lagophthalmos or scar contracture. In most cases, a releasing procedure is performed after 6 months of initial repair. However, if the patient has severe symptoms that are not relieved by conservative care, early revision is inevitable. We describe a case of early lagophthalmos successfully resolved with pentagonal wedge resection, fat redistribution, and full-thickness skin grafting. After the revisional surgery, we observed that the patient regained the ability to completely close the injured eyelid, with restoration of function and favorable cosmetic outcomes. Pentagonal wedge resection to release a retracted structure, fat redistribution to prevent readhesion, and full-thickness skin grafting for enough amount of skin to regain upper eyelid function is useful for scar release and lagophthalmos following crushing injuries of the upper eyelid.

• 한국지형학회지
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• 제24권3호
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• pp.27-45
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• 2017

At the upper part of terrace deposits at Jeongdongjin area, there is a structure in which reddish brown and grayish white layers laying horizontally. Previous studies have reported the existence of these structures within the deposits and suggested the theoretical background related to the formation process. However, the analysis of physical properties and chemical composition such as particle size, classification, etc. of the materials constituting the reddish brown and grayish white layers is scarcely done. In this study, the physico - chemical properties of gray - white and reddish brown beds are investigated. The mean grain size of the particles was less than $4{\varphi}$ in both layers and the reddish brown layer was more coarse. The results shows that the sorting of the grayish white layer is better. The chemical composition of both layers shows that the average concentration of $SiO_2$, $Al_2O_3$ and $K_2O$ of the grayish white layer was higher than those of the reddish brown layer. The concentration of $Fe_2O_3$ of reddish brown lyaer was 3 times higher than those of the grayish white layer. The degree of chemical weathering (CIA) is 90 or so in both the reddish brown and grayish white layers, indicating a significant level of chemical weathering. In conclusion, reddish brown layers had been formed by the processes related to the migration of iron and the migration of water that induced aggregation after the formation of sediments (psudo-gleization). In this study area, a vertical layer of grayish white which cuts off horizontal reddish brown and grayish white color was found. The vertical layer or wedge similar to a ice-wedge or columnar structure that in a cold environment, and there is a difference in shape and size. The vertical layer appears to have occurred three or more cycles. The vertical layers begin to form at a certain height within the outcrop and descend downwards, which of course is difficult to see as directing certain times.