• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.1
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• pp.83-94
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• 1999

본 연구에서는 시스템의 해석적 모델과 측정된 응답을 이용하여 입력하중을 추정하는 역해석 기법을 유한요소모델과 같은 해석적 모델을 알고 있는 경우와 주파수응답함수와 같은 실험적 모델을 알고 있는 경우에 대하여 제시하였으며 이때 발생되는 수학적 악조건의 특성을 규명하였다. 역해석시 발생되는 수학적 악조건은 시스템의 동강성행렬과 측정위치에 의해 결정되는 특성행렬의 조건수에 따라 결정되며 역해석기법을 공학문제에 적용하기 위하여는 특성행렬의 조건수가 낮아지도록 주자유도 및 측정점을 선택하여야 하고 특히 공진영역 및 반공진영역에서는 필연적으로 악조건이 발생됨을 알 수 있었다. 수학적 악조건의 특성을 명확히 규명하기 위하여 간단한 수치해석을 통하여 그 결과를 제시하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.4
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• pp.363-372
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• 2012

In this study, a new information-based hybrid modeling framework is proposed. In the hybrid framework, a conventional mathematical model is complemented by the informational methods. The basic premise of the proposed hybrid methodology is that not all features of system response are amenable to mathematical modeling, hence considering informational alternatives. This may be because (i) the underlying theory is not available or not sufficiently developed, or (ii) the existing theory is too complex and therefore not suitable for modeling within building frame analysis. The role of informational methods is to model aspects that the mathematical model leaves out. Autoprogressive algorithm and self-learning simulation extract the missing aspects from a system response. In a hybrid framework, experimental data is an integral part of modeling, rather than being used strictly for validation processes. The potential of the hybrid methodology is illustrated through modeling complex hysteretic behavior of beam-to-column connections.

• Communications of Mathematical Education
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• v.19 no.3 s.23
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• pp.543-556
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• 2005

우리 주변에는 수학영재 교육 대상자로 선발되어 영재교육을 받지 않는 학생 중에는 수학적으로 유망한 학생들이 많이 있으며, 이들에게 적절한 프로그램을 제공한다면 수학적 재능을 발휘할 수 있을 것이다. 본고에서는 수학적으로 유망성이 있는 학생들을 위한 프로그램 구성 및 운영 모델의 하나로 개방형 접근법(Open-approach heuristic)모델에 따른 구체적인 지도 방안과 프로그램에 대해서 살펴보고자 한다.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.147-162
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• 2007

This paper reports an analysis of 19 Chinese and Korean middles school mathematics teachers' understanding of division by fractions. The study analyzes the teachers' responses to the teaching task of generating a real-world situation representing the meaning of division by fractions. The findings of this study suggests that the teachers' conceptual models of division are dominated by the partitive model of division with whole numbers as equal sharing. The dominance of partitive model of division constraints the teachers' ability to generate real-world representations of the meaning of division by fractions, such that they are able to teach only the rule-based algorithm (invert-and-multiply) for handling division by fractions.

• Journal of the Korean School Mathematics Society
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• v.10 no.4
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• pp.557-571
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• 2007

The purpose of this paper was to develope a model for enhancement of mathematics education using participatory mathematics. Traditionally, mathematics has been considered ready-made and students need to practice it without real applications of mathematics. The 6th grade students in the two classrooms participated in the 60 class hours and the researcher and observers investigated students' achievements and reactions. In this model, students actively apply mathematics to real-life problems and futhermore change our life, which is one of the unique elements. Thus, students can experience mathematical power while they do mathematics. Every student need to experience with this model several times in a semester so that he or she can be active a citizen to change society a better place.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.178-184
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• 1997

Many mathematical techniques have been developed to determine the muscle forces and force distribution in biomechanical human model, because it is so important to understand internal forces resisting external loading. However, a three-dimensional mathematical model of wrist joint, which is essential to develop solid modeling and artificial wrist joint, has not been well developed. This study proposed to define three-dimensional mathematical model of distal radius and ulna of the human wrist and to develop a detailed two-dimensional finite element through comparisons to existing analytical models and experimental tests. This mathematical model were accurately recreated, allowing the internal tendon force as well as force transmission and distribution through the distal radios and ulna during dynamic loadings. The results found in this study indicate and support the findings of other investigator that cyclic loading condition results in higher compression force on distal radius and ulna and may be source of wrist disorder.

• School Mathematics
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• v.15 no.4
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• pp.785-799
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• 2013

The researchers developed the teaching-learning materials for 9th grade mathematically gifted students in terms of the hypothesis that the students would have opportunity for problem solving and develop various mathematical thinking through the mathematical modeling lessons. The researchers analyzed what mathematical thinking abilities were shown on each stage of modeling process through the application of the materials. Organization of information ability appears in the real-world exploratory stage. Intuition insight ability, spatialization/visualization ability, mathematical reasoning ability and reflective thinking ability appears in the pre-mathematical model development stage. Mathematical abstraction ability, spatialization/visualization ability, mathematical reasoning ability and reflective thinking ability appears in the mathematical model development stage. Generalization and application ability and reflective thinking ability appears in the model application stage. The developed modeling assignments have provided the opportunities for mathematically-gifted students' mathematical thinking ability to develop and expand.

• Journal of Educational Research in Mathematics
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• v.27 no.4
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• pp.857-888
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• 2017

Due to globalization, diversification, and informatization, modern society confronts change and crisis in a variety of areas such as economy, politics, and culture. In that context, mathematics educators seek for how to reform school mathematics for democratic and just society. This research proposes critical mathematics education as an alternative model of school mathematics for democratic society. In particular, this research is an explorative study to construct a model of critical mathematics education program. For the purpose, we conducted a comprehensive literature review to identify goals, contents, and methods of teaching and learning, and method of assessment for critical mathematics education. We checked the validity of the model by using the cases of critical mathematics education. Since this research is explorative in the regard that the model is based on theoretical literatures, further research is necessary to extend the model through design research in school context.

• Journal of the Korean School Mathematics Society
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• v.17 no.4
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• pp.657-677
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• 2014

The present qualitative case study explored the ways in which three middle school students constructed and refined their mathematical models and modeling processes, and factors that had influenced such refinement. The results suggest that students' modeling processes are non-sequential in that the participant students reformulated their initial problem from the real-world problem situation and revised the model when they could not get a satisfactory solution or the acquired solution did not make sense. Moreover, the students' model refinement processes were affected by the following four elements: the types of real-word problem situations, students' metacognitive thinking, communications between teachers and peers, and the role of teachers.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.5
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• pp.1-7
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• 2014

Distance based mobility management schemes have been considered as a major issue in the wireless network research area. Accordingly, many efforts have been made to analyze them numerically with suitable mobility models. In particular, bidirectional random walk model has been employed frequently due to its simplicity. Nevertheless, the exact equations are not presented so far. In this paper, we provide the exact equations regarding the bidirectional random walk model, which is very useful for the analysis of the distance based mobility management schemes.