• Structural Engineering and Mechanics
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• 제57권2호
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• pp.265-280
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• 2016

A NLFE model was proposed to investigate the mechanical behavior of short columns, cast using plain or fibrous lightweight aggregate concrete (LWAC), and subjected to elevated temperatures of up to $700^{\circ}C$. The model was validated, before its predictions were extended to study the effect of other variables, not studied experimentally. The three-dimensional NLFE model was developed using ANSYS software and involved rational simulation of thermal mechanical behavior of plain and fibrous LWAC as well as longitudinal and lateral steel reinforcement. The prediction from the NLFE model of columns' mechanical behavior, as represented by the stress-strain diagram and its characteristics, compared well with the experimental results. The predictions of the proposed models, considering wide range of lateral reinforcement ratios, confirmed the behaviors observed experimentally and stipulated the importance of steel confinement in preserving post-heating mechanical properties of plain and fibrous LWAC columns, being subjected to high temperature.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.417-420
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• 2006

For a better understanding of the fracture behavior of concrete structures, knowledge of the post-cracking behavior of concrete material is essential. The tension softening diagram can describe the post-cracking behavior of concrete in tension. In this paper, Four points bending tests with a notch have been carried out to investigate tensile properties of the steel fiber reinforced concrete(SFRC). Poly-linear approximation method combined with FEM analysis is applied to the steel fiber reinforced concrete to determine the tension softening diagrams and also to certify the validity of the method. The simulated load-CMOD curves using the determined softening diagrams though the poly-linear approximation method completely agree with the measured ones.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.183-185
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• 2008

Forming Limit Diagram(FLD) is a representative tool for evaluating formability of sheet metals. This paper presents a methodology to determine the FLD using Finite Element Method. For predicting the forming limits numerically. Previous methods such as using the thickness strain or the ductile fracture criterion are limited at plane strain domain. These results suggest that behavior of the void growth in sheet metals is different from real one. In contrast to previous methods, a more exact model which takes void growth into account is used. This result agrees with the experimental result qualitatively.

• 한국멀티미디어학회논문지
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• 제18권11호
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• pp.1281-1288
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• 2015

Nongroup Cellular Automata(CA) having two trees in the state transition diagram of a CA is suitable for pattern classifier which divides pattern set into two classes. Maji et al. [1] classified patterns by using multiple attractor cellular automata as a pattern classifier with dependency vector. In this paper we propose a method of generation of a pattern classifier using feature vector which is the extension of dependency vector. In addition, we propose methods for finding nonreachable states in the 0-tree of the state transition diagram of TPMACA corresponding to the given feature vector for the analysis of the state transition behavior of the generated pattern classifier.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.279-284
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• 2008

We propose the iconic animation of the software requirement specifications by using the object and dynamic models of the object modeling technique(OMT) methodology. In order to produce the iconic animation, we use "graphical classes" and "icon transformations." In general, the graphical classes are defined for each class of the object diagram. The icon transformations which show the activities of the application are constructed by considering the meaning of the activities and are defined by either basic or compound icons. The icon transformations are added to the state diagrams to generate extended state diagrams. The animation system generates the header files and the code instantiating GUI from the object diagram having graphical classes. The system also generates "event methods" from the extended state diagrams. When the event methods are executed, the behavior of the events is animated by the icon transformations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1565-1568
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• 1996

The adsorption and desorption behavior of orgnaic gases were investigated using the resonant frequency and admittance method. Sensitive material were depositied on the quartz crystal microbalence by using Langmuir-Blodgett method. To investigate the response characteristics of organic gases, Resonant frequency-Resonant admittance (F-A) diagram was used. The quantity and quality information about organic gases can be obtained by that diagram. As a results, when the organic gases were adsorpted into sensitive material, the physical property changees of sensitive material were occured.

• 폴리머
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• 제27권5호
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• pp.413-420
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• 2003

형광 현미경을 이용하여 4-클로로-7-니트로벤조퓨라잔이 표지된 폴리스티렌과 폴리부타디엔 블렌드 디옥틸프탈레이트 용액의 전단력하에서의 상평형 거동을 관찰하였다. 형광 현미경과 위상차 현미경을 동시에 사용하여 형광이미지가 실제 블렌드용액의 모폴로지와 같음을 알 수 있었다. 형광 현미경을 이용하여 각 도메인에서 형광의 세기를 측정함으로써 도메인상 (폴리스티렌 풍부상)과 연속 매트릭스상 (폴리부타디엔 풍부상)이 외부에서 가해준 전단력에 의하여 조성비가 변화하는 것을 관찰하였다. 이렇게 측정되어진 전단력의 변화에 따른 조성 차이의 변화로부터 상분리 곡선이 이동함을 알 수 있었다.

• 동력기계공학회지
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• 제9권4호
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• pp.83-89
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• 2005

Molding shrinkage is one of the problems to be solved in conventional injection molding. Despite many trying-out has been to solve it, intrinsic cause of shrinkage such as orientation and thermal exchange between melt and mold has not been solved yet. For reducing shrinkage and residual stress on molding, injection compression molding process was invented. In this study, experiments about effects of injection compression molding's parameters on shrinkage of PMMA molding were conducted and compared with conventional injection molding's shrinkage. Before the injection compression molding experiment, molding shrinkage rate was predicted by analyzing pvT diagram and was compared with the results of experiment. The shrinkage rate of injection compression molding was lower than convention injection molding's one which was different from the predicted shrinkage. The reason was observed that the experimental mold was not a proper type for injection compression, flowing backward of melt into nozzle and unreasonable mechanism of injection molding machine.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.225-231
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• 2005

This study aims to suggest an evaluation methodology of green-tourism potential for village level with amenity resources in rural areas. The amenity resources system was classified into three sub-classes(social, industrial, and natural/cultural/historical resources) and a relationship diagram between three classes and tourists' behavior was also defined. The methodology considers human resources in the village including the three sub-class amenity resources. The table and diagram were applied to make renewal plan for rural villages of the study area, Nami-myun, Keumsan-gun, Chungnam province, so that the development scheme for the villages was suggested reasonably by the new findings of this study.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.80-85
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• 1992

A nonlinear second-order analysis program that properly describes the nonlinear behavior of concrete was developed by using the layering technique. As the slenderness ratio of column is increased, the peaks of P-M curve lie remote from the section interaction diagram for the same eccentricities. But the peaks of P-M curve lie rather close to the section interaction diagram for very large eccentricities. In this study , the effects of compressive strength of concrete, longitudinal steel ratio, and yield strength of steel on second-order moment of concrete columns were analyzed. As the compressive strength of concrete and the yield strength of steel are increased, the ratio of peak axial force to maximum axial strength for concentrically loaded short column( Pu/Po) is decreased. But as the longitudinal steel ratio is increased, the ratio , Pu/Po increases.