• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.04a
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• pp.6-11
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• 1990

Inelastic behavior of reinforced concrete members is very complex and affected by many factors. Therefore, though using the finite element method which is good to predict the response of R/C member, it has to be proceeded to model these factors appropriately which have influence on the behavioral characteristics of reinforced concrete members. The proposed model consists of the physical single component model having the finite size of plastic regions and the hysteretic rules, by regressing experimental data, which can idealize the hysteretic behavior of R/C member under inelastic cyclic loads. This study confirms the accuracy of the developed analytical model through comparison with the test results of R/C members having a variety of shear-to-depth ratio and maximum shear stress.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.56.2-56.2
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• 2009

광촉매 $TiO_2$는 국내외적으로 큰 관심을 받고 있는데, 빛을 조사한 후에 물질에서 발생하는 다양한 물리 화학적 촉매특성이 환경정화 기능 및 에너지 문제와 밀접하게 연결되어 있기 때문이다. $TiO_2$는 자기정화기능, 초친수성, 고효율 수소생산성 및 태양전지로 활용성 등을 포함하여 다양한 분야의 친환경 소재로 각광을 받고 있다. Glass위에 evaporation법으로 제조된 $TiO_2$박막을 제조하고 특성을 평가하였다. 제조된 박막은 각각 $400,500,600^{\circ}C$에서 열처리를 실시하였다. 이렇게 제조된 $TiO_2$박막의 결정구조는 thin film형 X선 회절분석기를 사용하여 분석하였으며, 박막의 표면 및 미세구조는 FE-SEM과 AFM을 이용하여 분석하였다. 친수성 평가는 실온에서 UV를 조사하여 접촉각 측정기를 이용하여 측정하였다.

• Research in Mathematical Education
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• v.1 no.2
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• pp.127-137
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• 1997

수세기는 초등 수학교육의 기초로서 보통 유치원 과정 이전부터 시작된다. 그러나, 서수와 기수의 구별된 사용의 중요성은 미국의 "학교 수학의 교과 과정과 평가 기준" (NCTM 1989)에서 뿐만 아니라 학교 교육의 현장에서도 많이 간과되고 있는 실정이다. 일반적으로 사용되는 수직선 (Number line)과 다르게 구조적으로 개발된 Hasse's structured number line을 사용하여 학생들에게 수세기의 의미와 기술을 가르친다면 구체적 경험을 통해 수학적 사고 능력을 키우고 개발하는데 도움이 된다. 만약 Hasse 의 9가지 수준에 따라 다양한 학습 활동을 개발하여 수업 계획을 세워서 학습을 진행한다면 수업은 역동적이며 매우 흥미로워 질 것이다. 학생들은 말로 나타내기(Verbalization)와 상상(Imagination)의 충분한 경험을 바탕으로 정신적 표현(Mental representation)을 개발하여 수세기 기초를 확립하고 나아가 연산을 쉽게 수행할 수 있을 것이다. 여기에 소개된 교구들과 학습 활동들은 초등 수학 교육이 암기 위주의 문답식이 아니며 얼마나 역동적이고 흥미로울 수 있나를 보여준다.

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.262-263
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• 2008

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.160-161
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• 2008

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.172-173
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• 2008

• Proceedings of the Korea Concrete Institute Conference
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• 1990.10a
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• pp.19-22
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• 1990

Based on the design concept of a "Strong Column - Weak Beam" in the design of reinforced concrete, recently, a design method which moves the plastic hinging zone of a specific length away from the column face, has been proposed for reducing the degradation of stiffness and strength in the beam-column joint. To analyze reinforced concrete structures designed by this method. It is necessary to establish the analytical model which can simulate the hysteretic behavior depended on the initial positions and enlargements of plastic hinges. In this paper, by the numerical assumptions and the regression of experimental results, an analytical model is proposed. To estimate the accuracy of this model, some example analyses are conducted and compared with experimental results. From these comparision. It is shown that the proposed model is a good to predict the behavior of members subjected go cyclic loads.lic loads.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.5-8
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• 2004

In order to investigate the effect of the height of application point of lateral loads and reinforcing steel bars in walls and columns in improving the seismic behavior of confined concrete block masonry walls, an experimental research program is conducted. A total of four one-half scale specimens are tested under repeated lateral loads. Specimens are tested to failure with increasing maximum lateral drifts while a vertical axial load was applied and maintained constant. The constant vertical axial stresses applied are 0, 0.84 and 1.80MPa, while the amount of reinforcements in horizontal and vertical directions are $0\%,\;0.08\%\;and\;0.18\%$ respectively. Test results obtained for each specimen include cracking patterns, load-deflection data, and strains in reinforcement and walls in critical locations. Analysis of test data showed that above parameters generate a considerable effect on the seismic performance of confined concrete block masonry walls.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.623-626
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• 2004

The purpose of this paper is to study the effect of longitudinal reinforcement for anchoring in the wide beam column joint as wall as the contribution of depth of spandrel beam to hysteretic behavior of the wide beam column joint. From the test it was shown that the specimen with anchorage in the joint had higher strength than the specimen with normal hook anchorage. Specimen with debonded reinforcement at out of Id from column face failed showing moved plastic hinge and less strength than normal specimen. However, the dissipated energy was increased $11\%$.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.37-40
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• 2006

In this paper, long term deflection of RC beam with variable substitution ratio of recycled aggregate is investigated. 6 RC beam specimens are designed using concrete made of coarse aggregate of 25mm size, mix strength of 21MPa, slump of 12cm and air content of $5.0{\pm}1.5%$. A few concrete blocks are made and used for long term loading. The loading and deflection instrumentation are conducted following the process codified in ACI 318-05 code. Test result shows that the deflection of specimens depends on the compressive strength of concrete. And it is concluded that the deflection of RC beam can be predicted like normal beam using ACI formula if certain level of compressive strength is acquired even recycled aggregate is used in making the beam.