• Atmosphere
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• v.23 no.3
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• pp.283-291
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• 2013

This study investigates the changes in the atmosphere-ocean interactions over the South China Sea (SCS) by analyzing their variables in the period of 1979~2011 during the boreal summer (June-July-August). It is found that a simultaneous correlation coefficient between sea surface temperature (SST) and precipitation over SCS during summer is significantly changed before and after the late-1990s. That is, the variation of precipitation over SCS is negatively (positively) correlated with the SST variations before (after) the late-1990s. Our further correlation analysis indicates that the atmospheric forcing of the SST is dominant before the late-1990s accompanying with wind-evaporation feedback and cloud-radiation feedback. After the late-1990s, in contrast, the SST forcing of the atmosphere through the latent heat flux from the ocean to the atmosphere is dominant. It is found that the change in the relationship of atmosphere-ocean interactions over SCS are associated with the changes in the relationship with Northeast Asian summer precipitation. In particular, a simultaneous correlation coefficient between the precipitation over SCS and Northeast Asia becomes stronger during after the late-1990s than before the late-1990s. We argue that the increase of the SST forcing of the atmosphere over SCS may lead a direct relationship of precipitation variations between SCS and Northeast Asia after the late-1990s.

• Defense and Technology
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• no.9 s.235
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• pp.44-53
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• 1998

중국은 냉전의 종식 이후 이전에 지역 내에서 미소간의 대립을 중심으로 형성되어 있었던 세력균형이 점차 다원화되고 있음에 따라, 지역 내의 강국이 되고자 하는 목표를 가지고 있기 때문에 인접국가와 분쟁에 처하게 될 가능성은 매우 커 보인다. 이러한 점에서 중국의 해군력 강화는 향후 동아시아 지역의 안보환경과 관련하여 불확실성과 불안정성을 가중시키는 중요한 요인으로 작용할 것이다. 따라서 지역 내의 군비 경쟁을 촉진시키는 요인으로 작용할 것이다.

• 전기의세계
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• v.41 no.7
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• pp.13-21
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• 1992

전기에너지의 사용은 인류의 문명생활에 크게 기여하여 왔다. 그러나 사회가 더욱 복잡해지고 고도정보화를 추구함에 따라 전기에너지의 사용은 급증하고 다양해지고 있다. 이러한 시점에 인간이 전기에너지를 사용함에 따라 본래의 기능 이외의 역작용이 수반되고 있어 이에대한 제반의 역작용을 종합적으로 검토 분석하고 이를 최소화함으로써 쾌적한 전기환경보전하에서 본래의 전기사용목적을 달성하고 불필요한 전자에너지를 처리하고자 함을 목표로 하고 있다.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.155-155
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• 2011

일반적으로 I형 보에 횡하중이 작용하는 경우, 횡 변위와 함께 회전을 동반하는 횡-비틀림 좌굴(Lateral-Torsional Buckling)이 발생하게 된다. 이러한 I형 보의 탄성 및 비탄성 횡-비틀림 좌굴에 대한 해석적 이론적 연구는 이미 많은 연구자들에 의해 수행되었다(Timoshenko 등, 1961; Galambos, 1963; Lindner, 1974; Trahair, 1993). I형 보의 비지지 길이 내 하중이 작용할 때 모멘트 구배계수(Cb)는 하중이 부재 단면에 작용하는 위치에 따라 달라지게 되는데 이를 하중고 효과(Load Height Effects)라고 한다. 탄성 영역 내 비지지길이가 존재하는 I형 보의 하중고 효과를 고려한 모멘트 구배계수 제안식은 Nethercot & Rockey(1971)에 의해 연구된 바 있다. 또한 Helwig 등(1997)은 Nethercot & Rockey(1971)의 제안식을 간략화 하여 탄성 영역 내 비지지길이가 존재하는 I형 보의 하중고 효과를 고려한 모멘트 구배계수식을 제안하였다. 그러나 현재까지 진행 된 하중고 효과에 대한 연구는 탄성 영역 내 비지지 길이가 존재하는 I형 보에 대한 제안식이며 현재까지 비탄성 영역 내 비지지 길이를 갖는 I형 보의 하중고 효과에 대한 연구는 진행된 바 없다. 본 연구는 비탄성 영역 내 비지지 길이가 존재하는 I형 보의 하중고 효과를 고려한 비탄성 횡-비틀림 좌굴강도에 대한 연구를 수행하였다. 하중조건으로는 집중하중 과 등분포 하중을 적용시켰으며, 비선형 횡-비틀림 좌굴 해석을 위해 잔류응력 및 초기변형을 고려하였다. Pi와 Trahair(1995)이 고려한 단순직선분포를 잔류응력으로 가정하였으며, 국내 I형강 표준 치수 허용치(현대제철, 2006)에 근거하여 부재 길이의 0.1%를 초기 최대 횡 변위로 적용하여 초기제작오차로 고려하였다. 유한요소해석결과를 바탕으로 Nethercot & Rockey(1971)와 Helwig 등(1997)의 연구내용을 바탕으로 범용구조해석 프로그램(ABAQUS, 2007)을 이용하여 비탄성 영역 내 존재하는 I형보의 횡-비틀림 좌굴강도를 산정하였다. 유한요소해석결과를 바탕으로 Nethercot & Rockey(1971)및 Helwig 등(1997)의 모멘트구배계수 제안식과 비교 분석 하였고 회기분석프로그램 MINITAB(2006)을 이용하여 비탄성 영역 내 비지지길이가 존재하는 I형보의 하중고 효과를 고려한 모멘트구배계수식을 개발 제안하였다. 본 연구에서 개발된 제안식은 경제적이고 합리적인 휨부재 강도평가에 적극 활용될 수 있으며, 비탄성 영역내 I형보의 횡-비틀림 좌굴강도 및 휨강도 연구에 널리 활용될 것이다.

• Korean Journal of Culture and Social Issue
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• v.25 no.2
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• pp.157-177
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• 2019

In Study 1, the author translated the material which is modified by Han(2017) and allows researchers to examine misinformation effect about background (temporal structure of event) and object information. Eighty-five Korean participants were participated in Study 1 and tested their memory after misled by temporal and object post-event information about a story. The translated material could produce misinformation effect in both types of information. In Study 2, a 3-way ANOVA was conducted with combined data collected from Korea and the U.S to test the effects of three IVs (whether misled or not, the type of information and the nationality of the participants) on memory after misled by temporal and object information. As results, the main effects of all three IVs, the 2-way interaction effect of whether misled or not and the type of information, and the 3-way interaction effect of all the three IVs were statistically significant. In sum, the higher accuracy rate was obtained when the participants were not misled, and they were more accurate about the information about object. Americans tended to be more accurate. The misinformation effect was larger when the participants were misled by object information. The 2-way interaction effect was found only in the Korean sample. In the discussion, the implication of the current study was discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.2
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• pp.129-138
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• 2012

This paper deals with geometrical non-linear analyses of the tapered variable-arc-length beam, subjected to the combined load with an end moment and a point load. The beam is supported by a hinged end and a frictionless sliding support so that the axial length of the deformed beam can be increased by its load. Cross sections of the beam whose flexural rigidities are functionally varied with the axial coordinate. The simultaneous differential equations governing the elastica of such beam are derived on the basis of the Bernoulli-Euler beam theory. These differential equations are numerically solved by the iteration technique for obtaining the elastica of the deformed beam. For validating theories developed herein, laboratory scaled experiments are conducted.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.109-117
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• 2012

This study seeks to devise a design application for a beam structure with partially restrained composite connection to a CFT column. A cost-efficient and stable component is applied by adjusting the stiffness ratio of the column connection through partially restrained composite connection. Based on a review of the structure's stability, it was confirmed that in the case of a low-rise building as a moment frame, resistance without bracing is feasible because stiffness increased by virtue of the partial restrained composite connection by composite action. In the case of a high-rise building, lateral resistance load of moment frame was approximately 10% when proper partial restrained rate was at around 60%. With considerations related to economic efficiency, the partial restriction effect of the beam component was significantly activated by the uniform load, but that of the beam activated by concentrated load was not significantly indicative. The analysis indicated that 60% partial restrained girder at the connection was the most economical in the case of uniform load. It also showed that end moments can be reduced by approximately 25%.

• Magazine of the Korea Concrete Institute
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• v.9 no.5
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• pp.225-231
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• 1997

콘크리트 압축강도 및 전단스팬비의 변화에 의한 고강도 철근콘크리트 춤이 큰 보의 전단거동 및 내력특성을 파악하기 위한 실험적 연구를 하였다. 춤이 큰 보는 하중작용점과 하중지지점을 연결하는 사균열의 확대에 의해 취성전단파괴양상을 나타내었으며 하중작용점 하중 지지점의 콘크리트 압괴를동반하는 전단압축 및 전단인장파괴 형태로 최종파괴되었다. 전단스팬비가 감소함에 따라 사균열전단응력 및 최대전단응력은 크게 증가하였으며, ACI 및 CIRIA규준식은 부재의 최대전단응력을 비교적 정확하게 예측하고 있음을 파악하였다.

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

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.233-240
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• 1998

A rational expression, developed to predict the shear strength of reinforced concrete beams, is derived from the relationship between shear and the rate of change of bending moment along a beam coupled with experimental findings for the arch action. The proposed ultimate shear strength equation, arising from analytical premises and then calibrated with experimental data, is a similar form to the ACI 318 equation derived mainly from empirical approach. The proposed equation depends on the concrete compressive strength, amount of longitudinal steel content, and the shear span-to-depth ratio, and rationally reflects the shear resistance mechanism of combined beam action and arch action in reinforced concrete beams. The proposed equation applied to existing test data and the results were compared with those predicted by the ACI 318 equation and the Zsutty's equation.