• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1139-1142
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• 2009

Refinement of NMR structures by molecular dynamics (MD) simulations with a solvent model has improved the structural quality. In this study, we applied MD refinement with the generalized Born (GB) implicit solvent model to protein structure determined under membrane-like environments. Despite popularity of the GB model, its applications to the refinement of NMR structures of hydrophobic proteins, in which detergents or organic solvents enclose proteins, are limited, and there is little information on the use of another GB parameter for these cases. We carried out MD refinement of crambin NMR structure in dodecylphosphocholine (DPC) micelles (Ahn et al., J. Am. Chem. Soc. 2006, 128, 4398-4404) with GB/Surface area model and two different surface tension coefficients, one for aquatic and the other for hydrophobic conditions. Our data show that, of two structures by MD refinement with GB model, the one refined with the parameter to consider hydrophobic condition had the better qualities in terms of precision and solvent accessibility.

• Smart Structures and Systems
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• 제15권5호
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• pp.1329-1344
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• 2015

The stiffness of a structure is one of several structural signals that are useful indicators of the amount of damage that has been done to the structure. To accurately estimate the stiffness, an equation of motion containing a stiffness parameter must first be established by expansion as a linear series model, a Taylor series model, or a power series model. The model is then used in multivariate autoregressive modeling to estimate the structural stiffness and compare it to the theoretical value. Stiffness assessment for modeling purposes typically involves the use of one of three statistical model refinement approaches, one of which is the efficient Akaike information criterion (AIC) proposed in this paper. If a newly added component of the model results in a decrease in the AIC value, compared to the value obtained with the previously added component(s), it is statistically justifiable to retain this new component; otherwise, it should be removed. This model refinement process is repeated until all of the components of the model are shown to be statistically justifiable. In this study, this model refinement approach was compared with the two other commonly used refinement approaches: principal component analysis (PCA) and principal component regression (PCR) combined with the AIC. The results indicate that the proposed AIC approach produces more accurate structural stiffness estimates than the other two approaches.

• 대한수학교육학회지:학교수학
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• 제9권4호
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• pp.467-486
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• 2007

이 논문은 스프레드시트를 활용한 수학적 모델링에서 스프레드시트 환경이 수학적 모델의 정교화과정에 어떤 영향을 미치는 지를 고찰한 것이다. 좀 더 자세히 살피면 수학적 모델링에서 스프레드시트 모델의 활용은 학생이 분석 불가능한 수학적모델도 분석할 수 있도록 해줌으로써 모델을 단순화하지 않고, 대신 모델을 정교화 할 수 있는 기회를 제공하고 수학적 개념을 확장해 나갈 수 있음을 보였다. 또한 수학적 모델을 스프레드시트 모델로 변환하여, 수학적 모델로부터 수학적 결론을 얻는 단계를 거치지 않고도 실세계 상황을 해석하고 설명할 수 있는 기회를 제공할 수 있음을 보였다.

• 자원리싸이클링
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• 제30권1호
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• pp.14-25
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• 2021

고품질 철강의 수요가 증가함에 따라 2차 정련 공정의 중요성이 높아지고 있다. 하지만 공정 시간에 따라 변화하는 용강, 슬래그 및 비금속 개재물의 조성은 정련 공정이 평형 상태가 아님을 의미하며, 정련 공정에서는 용강, 슬래그, 비금속 개재물, 내화물 및 합금 원소 간의 동시 다발적 반응이 일어난다. 다양한 상들의 비평형 상태에서 복잡한 반응을 고려하기 위해, 이전 연구자들은 실험을 통해 도출된 반응 속도 수식들을 기반으로 kinetic 기반의 고급강 제조 정련 시뮬레이션 모델을 발표하였다. 정밀한 시뮬레이션 모델의 개발을 위해 보고된 2차 정련 모델들의 분석 및 검토가 필요하다. 본 연구에서는 국내외로 발표된 정련 공정 관련 종합 모델들 및 단일 반응 모델들에 대하여 검토하고 소개하였다.

• 대한기계학회논문집B
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• 제39권5호
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• pp.415-423
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• 2015

본 연구에서는 2차원 비압축성 유체 유동을 해석하기 위하여 격자 세밀화 모델을 적용한 격자볼츠만 방법(LBM)을 수치적으로 연구하였다. 일반적으로 유동해석에서 충분한 정확도를 얻기 위해서는 관심 있는 영역에서 격자가 세밀하게 구성되어야 한다. 그래서 본 연구에서는 유동함수-와도 공식을 적용한 LBM에 격자 세밀화 모델을 적용하여 유동해석을 수행하였다. 공동형상 유동에서의 기존의 신뢰성 있는 유동장 결과와의 비교를 통해 본 연구의 격자 세밀화 모델을 적용한 격자볼츠만 방법의 신뢰성과 유용성을 검토하였다.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1844-1853
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• 2001

In the present investigation, it was attempted to design the rolling pass schedule fur a clean steel of 0.1C-1.5Mn-0.25Si with the objective of the austenite grain refinement. As the method of approach, a coupled mathematical modeling technique was proposed which consists of a recrystallization model and a flow stress modes. The validity of the coupled model was examined through comparison with results of continuous and discontinuous compression tests at various temperatures, strains and strain rates. The coupled model was incorporated with the finite element method to set up a systematic design methodology far the rolling path schedule for austenite grain refinement. Two path schedules were obtained and discussed in the paper with regard to rolling path time, average grain size, grain size deviation in thickness, etc.

• 한국컴퓨터정보학회논문지
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• 제21권12호
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• pp.97-105
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• 2016

Network-Centric Operational Environment(NCOE) service becomes critical in today's military environment network because reusability of service and interaction are being increasingly important as well in business process. However, the refinement of service by semantic similarity and functional similarity at the business process was not detailed yet. In order to enhance accuracy of refining of business service, in this study, the authors introduce a method for refining service by semantic similarity and functional similarity in BPMN model. The business process are designed in a BPMN model. In this model, candidated services are refined through binding related activities by the analysis result of semantic similarity based on word-net and functional similarity based on properties specification between activities. Then, the services are identified through refining the candidated service. The proposed method is expected to enhance the service identification with accuracy and modularity. It also can accelerate more standardized service refinement developments by the proposed method.

• 한국학교수학회논문집
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• 제17권4호
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• pp.657-677
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• 2014

본 연구의 목적은 실험수업에 참여한 세 명의 중학교 1학년 학생들의 모델 정교화 과정을 질적 사례연구를 통하여 살펴보고 모델 정교화에 영향을 미치는 요인을 분석하여 이에 관한 정보를 제공하고자 함이다. 분석 결과 학생들의 수학적 모델링의 정교화 과정은 각 단계가 단선적으로 일어나는 것이 아니라 모델 내에서 해를 구할 수 없거나 구한 해가 의미가 없는 경우 실제 문제 구성 단계로 돌아가 실제 문제를 수정하거나 수학적 모델 구성 단계로 돌아가 모델을 수정 또는 정교화하는 것을 알 수 있었으며, 모델 정교화 과정에 영향을 미치는 요인으로는 모델링 문제, 메타인지적 사고, 교사 동료와의 의사소통 및 교사의 역할 등이 복합적으로 작용함이 나타났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.122-122
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• 2020

Urban flood simulation plays a vital role in national flood early warning, prevention and mitigation. In recent studies on 2-dimensional flood modeling, the integrated run-off inundation model is gaining grounds due to its ability to perform in greater computational efficiency. The adaptive quadtree shallow water numerical technique used in this model implements the adaptive mesh refinement (AMR) in this simulation, a procedure in which the grid resolution is refined automatically following the flood flow. The method discounts the necessity to create a whole domain mesh over a complex catchment area, which is one of the most time-consuming steps in flood simulation. This research applies the dynamic grid refinement method in simulating the recent extreme flood events in Metro Manila, Philippines. The rainfall events utilized were during Typhoon Ketsana 2009, and Southwest monsoon surges in 2012 and 2013. In order to much more visualize the urban flooding that incorporates the flow within buildings and high-elevation areas, Digital Surface Model (DSM) resolution of 5m was used in representing the ground elevation. Results were calibrated through the flood point validation data and compared to the present flood hazard maps used for policy making by the national government agency. The accuracy and efficiency of the method provides a strong front in making it commendable to use for early warning and flood inundation analysis for future similar flood events.

• 반도체디스플레이기술학회지
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• 제12권1호
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• pp.1-7
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• 2013

Grey-level statistical models have been widely used in many applications for object location and identification. However, conventional models yield some problems in model refinement when training images are not properly aligned, and have difficulties for real-time recognition of arbitrarily rotated models. This paper presents improved grey-level statistical models that align training images using image or feature matching to overcome problems in model refinement of conventional models, and that enable real-time recognition of arbitrarily rotated objects using efficient hierarchical search methods. Edges or features extracted from a mean training image are used for accurate alignment of models in the search image. On the aligned position and orientation, fitness measure based on grey-level statistical models is computed for object recognition. It is demonstrated in various experiments in PCB inspection that proposed methods are superior to conventional methods in recognition accuracy and speed.