• 산업공학
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• 제9권2호
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• pp.191-202
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• 1996

A variety of approaches on performance evaluation modeling have appeared in the technical literature for flexible manufacturing systems(FMS) which can be evaluated only through computer simulation. This study represents a comparative approach for FMS performance evaluation modeling based on reliability, availability and maintainability, and life cycle cost. The methodology proposed in this research includes the following three-step generative approaches. First, a static model to find the initial system configuration is considered under the assumption that the system availability is given as one (failure and maintenance are not considered), and in second step, a stochastic simulation is proposed to serve as a performance evaluation model for FMS with stochastic failure and repair time. In the last step, we developed a simulation modeling using a simulator, FACTOR/AIM to consider a variety of performance factors and dynamic behavior of FMS. Also the applicability and validity of the proposed approaches has been tested and compared through the results of a sample problem using computer programs and procedures developed in each step.

• 한국과학교육학회지
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• 제34권6호
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• pp.583-592
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• 2014

이 연구는 글쓰기를 활용한 논의-기반 모델링 전략이 학생들의 모델링 능력에 미치는 영향을 알아보는 것을 목적으로 하였다. 또한 논의-기반 모델링 전략에서 다중표상의 적용여부가 학생들의 모델링 능력에 미치는 효과를 비교하였다. 이를 위해 남녀공학 중학교 1학년 세 개 학급(66명) 중 두 개 학급(43명)은 실험집단으로, 한 개 학급(23명)은 비교집단으로 선정하였다. 논의-기반 모델링 전략을 적용한 두 개 실험집단 중에서 한 개 학급은 AbRM집단(Argument-based multimodal Representation and Modeling, 논의-기반 다중표상 및 모델링 집단, 22명), 다른 한 개 학급은 AbM집단(Argument-based Modeling, 논의-기반 모델링 집단, 21명), 나머지 한 개 학급은 비교집단(23명)으로 선정하였다. 논의-기반 모델링 전략은 인지 과정, 해석 과정, 적용과정으로 구성되어 있다. 실험집단은 논의-기반 모델링 전략의 인지과정과 해석 과정을 공통적으로 수행하고 적용 과정에서 차이를 두었다. AbRM집단은 논의-기반 다중표상 및 모델링을 적용하였고, AbM 집단은 논의-기반 모델링을 적용했으며, 비교집단은 전통적 수업방식을 적용하였다. 논의-기반 모델링 전략이 학생들의 모델링 능력에 미치는 영향을 분석한 결과, AbRM집단의 경우 통합적 모델링 수준에서 다른 두 집단보다 통계적으로 유의미하게 높았고, AbM집단은 비교집단보다 유의미하게 높았다. 모델링 능력 검사의 하위요소인 문제인식, 과학개념 구조화, 주장-증거 적절성, 다중표상 지수에서 AbRM집단의 경우 모든 하위요소에서 AbM집단과 비교집단 보다 통계적으로 유의미하게 높았으며, 그 다음으로 AbM집단이 비교집단 보다 통계적으로 유의미하게 높았다. 이러한 결과로부터 논의-기반 모델링 전략은 모델링의 목적인 의사소통을 위해 자신이 만든 모델을 논의와 글쓰기를 통해 과학적 언어를 사용하여 스스로 정리하거나 표현하고, 다른 사람의 의견을 듣고 교환하는 과정을 통해 모델을 평가하고 수정하는 일련의 과정을 통해서 학생들의 모델링 능력의 향상에 효과적임을 보여주었다.

• Bioinformatics and Biosystems
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• 제1권1호
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• pp.82-87
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• 2006

현재 가장 많이 사용되는 단백질 구조 예측 방법은 비교 모델링 (comparative modeling) 방법이다. 비교 모델링 방법에서의 정확도를 높이기 위해서는 alignment의 정확도 역시 매우 필수적으로 필요하다. 비교 모델링 과정 중의 fold-recognition 단계에서 alignment의 정확도에 의해 template을 고르는 방법은 단지 가장 비슷한 template을 선택하는 방법에 비해 주목을 받지 못하고 있다. 최근에는 두 가지의 alignment에 사이의 shift 정보를 바탕으로 한 shift score라는 수치가 alignment의 성능을 표현하기 위해서 개발되었다. 우리는 더 정확한 구조 예측의 첫걸음이 될 수 있는 shift score를 예측하는 방법을 개발하였다. Shift score를 예측하기 위해 support vector regression (SVR)이 사용되었다. 사전에 구축된 라이브러리 안의 길이가 n 인 template과 구조를 알고 싶은 query 단백질 사이의 alignment는 n+2 차원의 input 벡터로 변환된다. Structural alignment가 가장 좋은 alignment로 가정되었고 SVR은 query 단백질과 template 단백질의 structural alignment과 profile-profile alignment 사이의 shift score를 예측하도록 training 되었다. 예측 정확도는 Pearson 상관계수로 측정되었다. Training 된 SVR은 실제의 shift score와 예측된 shift score 사이에 0.80의 Pearson 상관계수를 갖는 정도로 예측하였다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제27권1호
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• pp.25-47
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• 2024

Mathematical modeling activities are gaining popularity in K-12 mathematics education curricula worldwide. These activities serve dual purposes by aiding students in making sense of real-world situations intertwined with social justice while acquiring mathematical knowledge. Despite efforts to prepare teacher candidates for instructing in mathematical modeling within a single country, little attention has been given to teacher candidates' approaches to mathematical modeling on a social justice issue from different countries. This article employs an in-depth, small-scale comparative study to examine the approaches of U.S. and Korean teacher candidates in solving a justice-oriented mathematics task. Our findings reveal that, although both U.S. and Korean teacher candidates identified certain variables as key when constructing a mathematical model, Korean teacher candidates formulated a more nuanced model than U.S. candidates by considering diverse variables. However, U.S. teacher candidates exhibited a heightened engagement in linking the task to social justice issues, whereas Korean teacher candidates barely perceived real-world problems in relation to social justice concerns. This study serves as a valuable tool to inform the roles and limitations of teacher education programs, shaped within specific educational contexts.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제16권2호
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• pp.137-154
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• 2012

Comparative studies on mathematical modeling cognition feature were carried out between 15 excellent high school third-grade science students (excellent students for short) and 15 normal ones (normal students for short) in China by utilizing protocol analysis and expert-novice comparison methods and our conclusions have been drawn as below. 1. In the style, span and method of mathematical modeling problem representation, both excellent and normal students adopted symbolic and methodological representation style. However, excellent students use mechanical representation style more often. Excellent students tend to utilize multiple-representation while normal students tend to utilize simplicity representation. Excellent students incline to make use of circular representation while normal students incline to make use of one-way representation. 2. In mathematical modeling strategy use, excellent students tend to tend to use equilibrium assumption strategy while normal students tend to use accurate assumption strategy. Excellent students tend to use sample analog construction strategy while normal students tend to use real-time generation construction strategy. Excellent students tend to use immediate self-monitoring strategy while normal students tend to use review-monitoring strategy. Excellent students tend to use theoretical deduction and intuitive judgment testing strategy while normal students tend to use data testing strategy. Excellent students tend to use assumption adjustment and modeling adjustment strategy while normal students tend to use model solving adjustment strategy. 3. In the thinking, result and efficiency of mathematical modeling, excellent students give brief oral presentations of mathematical modeling, express themselves more logically, analyze problems deeply and thoroughly, have multiple, quick and flexible thinking and the utilization of mathematical modeling method is shown by inspiring inquiry, more correct results and high thinking efficiency while normal students give complicated protocol material, express themselves illogically, analyze problems superficially and obscurely, have simple, slow and rigid thinking and the utilization of mathematical modeling method is shown by blind inquiry, more fixed and inaccurate thinking and low thinking efficiency.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.65-70
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• 1998

Soil moisture measuring is important for irrigation scheduling of upland crops, estimation of evapotranspiration, and hydrologic modeling. Hence, the comparative study was implemented for the soil moisture measuring instruments, Neutron probe and TDR with soil sampling methods, and the result was represented.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.186-192
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• 1999

Safety-related equipments of nuclear power plant must be seismically qualified to demonstrate their ability to function as required during and/or after the earthquake, The seismic qualification is usually achieved through analysis and testing. Analysis method is preferably adopted for structurally simple equipments which are easy to be mathematically modeled. However even for relatively complex equipments analysis method is occasionally used for computing the input motion or supporting information for the component test followed. Electrical cabinet is a typical example for which analysis method is combinedly used with test to get modal properties of the enclosing cabinet structure. Usually the structural elements and doors of the cabinet are loosely interconnected with small-size bolts or spot welding. Therefore cabinet-type equipment usually has high and complex nonlinear properties which are not easily idealized by simple practical modeling techniques. in this paper with respect to a typical cabinet-type structure(instrumentation cabinet of nuclear power plant) a comparative study has been performed between three different state-of-the -art modeling techniques: lumped mass model frame model and FEM modal. Form the study results it has been found that modal properties of the cabinet-type structure in the elastic behavior range can be reasonably computed through any type of modeling techniques in the practice with slight modification of model properties to get better accuracy. However it needs additional modeling techniques to get reasonable results up to nonlinear range.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.668-671
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• 2010

무차원 추진제 모델링 기법과 1차원 추진제 모델링 기법을 사용하여 약실 내 추진제 모델링 기법에 대한 비교 연구를 수행하였다. 무차원 추진제 모델링의 경우 약실 내 추진제 위치 및 배열에 대한 묘사가 불가능 하지만 1차원 추진제 모델링의 경우에는 가능하다. 따라서 약실 내 추진제 배열에 따른 강내탄도 성능해석 시 무차원 추진제 모델링의 경우 강내 마이너스 차압의 예측이 불가능하지만 1차원 추진제 모델링의 경우 예측이 가능함을 확인했으며, 이를 통해 강내탄도 성능해석 시 1차원 추진제 모델링의 필요성을 확인했다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제27권1호
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• pp.49-73
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• 2024

This study aims to explore the direction of high school statistics education in Korea through a comparative analysis between the revised 2022 Korea mathematics curriculum and the IBDP Mathematics: Application & Interpretation Standard Level (IBDP AI SL) Curriculum and textbooks. The study seeks to investigate the Statistics unit of the two curricula, compare chapter structures and content elements of textbooks, and explore exercises on modeling and utilization of technology tools. The results are as follows: First, the IBDP AI SL statistics covered a broader range of topics. Second, exercises in Korean high school textbooks typically inquire about one or two questions in each topic, whereas the IBDP AI SL textbook's exercises present a real-life scenario on all relevant topics through sub-questions. Third, the Korean textbook guides the utilization of technology tools only in exercises presented after completing the entire chapter or where the calculation is complex. Also, there were only a handful of modeling exercises in the Korean textbook in contrast to most of the lessons and exercises were modeling exercises in the IBDP AI SL textbook. If these findings can be integrated into teaching practices in Korea, it will provide a direction for statistics education in Korean high schools.

• 한국항공운항학회지
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• 제28권1호
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• pp.59-65
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• 2020

This paper presents comparative results of configuration modeling and aerodynamic analysis to single-engine airplanes such as C-172, SR-20, and DA40NG. The software OpenVSP was used as an airplane configuration modeling tool. OpenVSP can provide the fastest method to get three-dimensional aircraft configuration from given basic data and drawings of aircraft. Parametric design input in OpenVSP, from given aircraft geometric parameters, was applied to small airplanes mentioned. New aircraft models in this study were reversely designed to coincide with the publicly obtained dimensions of the original aircraft. The basic aerodynamic analysis of newly designed modeling aircraft was performed by the vortex lattice method. Results are shown that the similarity of aerodynamic data obtained except for the lack of DA40NG. In conclusion, the modeling process applied to this work is valuable to obtain conceptual design insight in the reverse design from the small airplanes currently in use for flight training.