• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.451-452
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• 2005

In this study, the threshold voltage and the response time of thermal stressed TN-LCDs showed the same performances on none thermal stressed TN-LCDs. There was little change in TN cells. Also, while increasing thermal stress time, the transmittances of TN-LCDs on the rubbed PI surface were almost the same, But the thermal stability of TN cell was deteriorated.

• 한국전기전자재료학회논문지
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• 제22권2호
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• pp.184-190
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• 2009

One of the purposes of arc control is to change its state to the diffuse state before current zero as soon as possible. This can provide optimal conditions for full extinction of arc by minimizing the quantity of residual plasma between contacts near current zero. TRV(transient recovery voltage) occurs at current zero at the same time with current interruption. If there is substantial residual plasma near current zero it can cause 'post arc current' by the interaction of its conductance with TRV. In this paper, arc control ability as a function of configuration of spiral type VI contacts was compared on the criteria of the time taken for arc to reach to the diffuse state.

• 소성∙가공
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• 제6권2호
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• pp.118-135
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• 1997

In order to analyze the deformation and residual curvature of steel sheets in the strip processing lines, a program for calculating curvature and work hardening of sheet was developed. Strip deformation caused by repeated bending under tension in the process lines was analyzed on the basis of the incremental-plasticity theory with the mixed hardenting model for the purpose of predicting the strip shape and the yield stress change. The developed calculation program was applied to predict curl and gutter of sheets within a 10% difference. The yield stress increment was also predicted with the similar accuracy. Application of the model to tension legvelling process showed that gutter could be controlled by intermesh and elongation. The yield stress increment in the electro-galvanizing line calculated by the developed program was found to be dependent on the yield strength, the applied tension and the diameter of the smallest roll.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.620-625
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• 1995

Finite element analysis tool was developed to analyze the casting process. Generally, casting processes consists of mold filling and solifification. In order to investigate the effects of process variables and to predict the defects, both filling and solidiffication process were simulated simultaneously. At filling process, especiallywe consider thermal coupling to investigate thermal history of material during the filling stage. And thermal condition at the final stage of filling is used as the initial conditions in a solidification process for the exact simulation of the actual casting processes. At mold filling process, Lagrangian-type finite element method with automatic remashing scheme was used to find the material flow. To avoid numerical instability in low viscous fluid, a perturbation method with artificial viscosity is adopted. At solififfication process, enthalpy-based finite element method was used to solve the heat transfer problem with phase change. And elastic stress analysis has been performed to predict the thermal residual stress. Through the FE analysis, solidiffication time, position of solidus line, liquidus line and thermal residual stress are studied. Finite element tools developed in this study will be used process design of casting process and maybe basic structure for total CAE system of castigs which will be constructed afterward.

• 한국자기공명학회논문지
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• 제22권4호
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• pp.76-81
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• 2018

Investigation of the protein-protein interaction mode at atomic resolution is essential for understanding on the underlying functional mechanisms of proteins as well as for discovering druggable compounds blocking deleteriou interprotein interactions. Solution NMR spectroscopy provides accurate and precise information on intermolecular interactions even for weak and transient interactions, and it is also markedly useful for examining the change in the conformation and dynamics of target proteins upon binding events. In this mini-review, we comprehensively describe three unique and powerful methods of solution NMR spectroscopy, paramagnetic relaxation enhancement (PRE), pseudo-contact shift (PCS), and residual dipolar coupling (RDC), for the study on protein-protein interactions.

• 대한건축학회논문집:구조계
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• 제34권1호
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• pp.27-32
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• 2018

This work provides the analytical methods to represent the updated form of stiffness or flexibility matrices using the measurements of the first few natural frequencies and the corresponding mode shapes. This study derives the mathematical forms on the variance of stiffness or flexibility matrices to minimize the performance index in the satisfaction of the eigen-function including the residual force depending on the measured data. The proposed methods can be utilized in detecting damage and updating the parameter matrices deviated from the analytical parameter matrices. The validity of the proposed methods is investigated in a numerical experiment of truss structure and the numerical results of stiffness-based and flexibility-based methods are compared. The sensitivity to the external noise is also examined for applying to the practical work.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.115-116
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• 2022

This study incorporates fine waste glass (GS) as a replacement for natural sand (NS) in fly ash (FA) based alkali activated mortar (AAm). AAms were heated at elevated temperature of 200℃, 400℃, 600℃, and 800℃ to explore the residual mass, compressive strength, thermal expansion and change in microstructure of matrix. Results showed greater resistance of AAms with increasing GS content to 50% at each temperature. Owing to the melting of GS at 800℃, the greater matrix bond was observed for AAm incorporating 75% and 100% GS as a result, the residual compressive strength was increased.

• 한국정밀공학회지
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• 제10권3호
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• pp.47-56
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• 1993

Typical plastic strains in the machined surface are very difficult to measure, since they are located within a very short distance from the surface and they change very rapidly. There is an alternative way to determine the residual strain in plastically deformed materials by measuring the grain size after a subsequent recrystallization precess. Although, this technique has been successfully applied by several researchers to find the plastic zone around notches and cracks in various materials and welding beads, few works have been reported using the recrystallization method to determine the residual strains in machined surface. Therefore, the purpose of this investigation is to explore the effectiveness of the recrystallization technique in machining applications and in particular, to find the effect of cutting parameters, i.e., depth of cut, rake angle, on the plastic strains. As the result, the recrystallization technique was succesfully applid to determine the plastic strain in machined surface.

• 한국해안·해양공학회논문집
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• 제20권1호
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• pp.62-72
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• 2008

본 연구에서는 흐름에 수직한 방향으로 급격한 수심 변화가 존재하는 해역에서 점열원에 의한 열오염 분포를 예측할 수 있는 해석 모델을 개발하였다. 개발된 모델을 이용하여 열오염 분포에 있어 수심 변화와 흐름효과를 검토하였다. 계산 결과 흐름에 수직한 방향으로 수심 변화가 존재할 경우 수평 확산 플럭스의 증감으로 인해 수심 변화 경계를 가로지르는 열의 이동이 증가하거나 감소하는 것으로 나타났다. 조류와 동시에 잔차류 성분을 포함할 경우에는 이류에 의한 열오염 수송 효과가 증가하여 수심 변화 경계를 가로지르는 수평 확산은 상대적으로 감소하였다.

• 한국분말재료학회지
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• 제29권3호
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• pp.219-225
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• 2022

An alternative fabrication method for carburizing steel using spark plasma sintering (SPS) is investigated. The sintered carburized sample, which exhibits surface modification effects such as carburizing, sintered Fe, and sintered Fe-0.8 wt.%C alloys, is fabricated using SPS. X-ray diffraction and micro Vickers tests are employed to confirm the phase and properties. Finite element analysis is performed to evaluate the change in hardness and analyze the carbon content and residual stress of the carburized sample. The change in the hardness of the carburized sample has the same tendency to predict hardness. The difference in hardness between the carburized sample and the predicted value is also discussed. The carburized sample exhibits a compressive residual stress at the surface. These results indicate that the carburized sample experiences a surface modification effect without carburization. Field emission scanning electron microscopy is employed to verify the change in phase. A novel fabrication method for altering the carburization is successfully proposed. We expect this fabrication method to solve the problems associated with carburization.