• IE interfaces
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• v.9 no.2
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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.

• Journal of The Korean Association For Science Education
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• v.34 no.6
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• pp.583-592
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• 2014

The purpose of this study is to investigate the impact of argument-based modeling strategy using scientific writing on student's modeling ability. For this study, 66 students (three classes) from the 7th grade were selected and of these, 43 students (two classes) were assigned to two experimental groups while the other 23 students (one class) were assigned to comparative group. In the experimental groups, one group (22 students) was Argument-based multimodal Representation and Modeling (AbRM), and the other group (21 students) was Argument-based Modeling (AbM). Modeling ability consisted of identifying the problem, structuring of scientific concepts, adequacy of claim and evidence and index of multimodal representation. As for the modeling ability, AbRM group scored significantly higher than the other groups, AbM group was significantly higher than comparative group. The four sub-elements of modeling ability in the AbRM group was significantly higher than the other groups statistically and AbM group scored significantly higher than comparative group. From these results, the argument-based modeling strategy using scientific writing was effective on students' modeling ability. Students organized or expressed the model and evaluated or modified it through the process of argument-based modeling using scientific writing and the exchange of opinions with others by scientific language as argument and writing.

• Bioinformatics and Biosystems
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• v.1 no.1
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• pp.82-87
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• 2006

The most popular protein structure prediction method is comparative modeling. To guarantee accurate comparative modeling, the sequence alignment between a query protein and a template should be accurate. Although choosing the best template based on the protein sequence alignments is most critical to perform more accurate fold-recognition in comparative modeling, even more critical is the sequence alignment quality. Contrast to a lot of attention to developing a method for choosing the best template, prediction of alignment accuracy has not gained much interest. Here, we develop a method for prediction of the shift score, a recently proposed measure for alignment quality. We apply support vector regression (SVR) to predict shift score. The alignment between a query protein and a template protein of length n in our own library is transformed into an input vector of length n +2. Structural alignments are assumed to be the best alignment, and SVR is trained to predict the shift score between structural alignment and profile-profile alignment of a query protein to a template protein. The performance is assessed by Pearson correlation coefficient. The trained SVR predicts shift score with the correlation between observed and predicted shift score of 0.80.

• Research in Mathematical Education
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• v.27 no.1
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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.

• Research in Mathematical Education
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• v.16 no.2
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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.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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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.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.668-671
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• 2010

Comparative study on propellant modeling has been investigated using a non-dimensional method and an one-dimensional method. The propellant location in the chamber can not be described by the non-dimensional method. It is, however, possible for the one-dimensional method to describe. Therefore, the analysis of the interior ballistics according to the propellant arrangements has been performed by the one-dimensional method. The negative differential pressure in the chamber could be predicted and the necessity of the one-dimensional modeling for the analysis of the interior ballistics has been confirmed.

• Research in Mathematical Education
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• v.27 no.1
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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.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.1
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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.