• School Mathematics
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• v.15 no.3
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• pp.569-583
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• 2013

In Korea, the school mathematics curricula have been revised in every average 6 years by the government. From the year 2013, the new revised curricula called 2009 version are implied. The subject of elementary mathematics in this new curricula contains four issues to be improved. First, it should be allowed to call the basic figures such as box, cylinder, ball, quadrilateral, triangle and circle in verbal languages. Second, the name of the activities to define mathematical concepts should be changed from 'Yaksok', which means 'promise' in English, to a better and more honest one. Third, the concave polygons should be treated together with the convex ones. Fourth, the calculations of fractions should be weakened as much as possible for the elementary school children.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.5 s.118
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• pp.59-69
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• 2006

Nature-learning place is a critical space together with nature center in Natural parks. But there are serious faults on these design and planning as for the landscape ecological consideration. The objective of this paper was to suggest the ecological alternatives through analyzing existing cases of nature-teaming place in Natural parte. Five case sites in Natural parks were selected in Chollabukdo. Three landscape indices- subjectivity, natural prototype, nativity, were introduced for evaluating the existing cases. Results showed that those are short of landscape ecological senses- Biotope target species, ecological vegetation patches, eco-corridor concept. A proposal for the ecological planning in Deokyusan Natural park was suggested according to several criteria with biotopes as forest and stream patches and the corridor. The results of the study can be summarized as follows. First, existing natural-loaming sites should be evaluated in light of landscape ecological indices. Second, they can be designed to work with the concept of the biotope patch and corridor for target species. The results of this study could provide critical guidelines for the ecological planning and design of natural-loaming sites in nature parks.

• The Mathematical Education
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• v.50 no.2
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• pp.135-148
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• 2011

We can say that the history of mathematics is the history on the development of the number system. The number starts from Natural number and is constructed to Integer number and Rational number. The Rational number is not the complete number analytically so that Real number is completed by the idea of the nested interval method. Real number is completed analytically, however, is not by algebra, so the algebraically completed type of the rational number, through the way that similar to the process of completing real number, is Complex number. The purpose of this study is to show the most appropriate way for the development of the human being thinking about the teaching and leaning of Complex number. To do this, We have to consider the proof of the existence of Complex number, the background of the introduction of Complex number and the background knowledge that the teachers to teach Complex number should have. Also, this study analyzes the knowledge to be taught of Complex number based on the anthropological theory of didactics and finally presents the teaching method of Complex number based on this theory.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.219-221
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• 2004

국가의 규제기관과 처분장에서는 방사성 폐기물의 안전한 영구처분을 위하여 폐기물 수용(인수)기준을 폐기물 발생자에게 준수토록 요구하게 되는데 이러한 폐기물 수용(인수)기준은 처분시설의 가동동안 인간과 환경 보호 그리고 최대 300년간의 제도적 통제기간을 고려하여 처분장의 안전성 확보를 위하여 설정되어진다. 폐기물 수용(인수)기준중 고화체의 안정성 평가와 관련하여 미국(NRC/BTP)은 폐기물의 종류와 고화매질에 따라 유리수, 압축강도, 방사성 조사특성, 미생물 영향 특성, 침수 및 침출 특성, 열순환 특성 등에 대하여 표준시험법을 제시하였으며, 또한 그의 기술기준치도 제시하고 있다. 그리고 프랑스(DRDD/ BECC)에서는 미국보다 매우 세밀하게 평가항목들을 분류하는 등의 처분장 운영국가에서는 고화체의 안정성관련 평가시험들을 처분 환경과 처분방식에 맞게 표준화하고 있다. 한편 국내에서는 과기부 고시 제2001-32호 "중.저준위 방사성폐기물 인도규정"이 있으나 이에는 고화체 관련하여 정성적인 안정성에 대하여서만 기술되어 있다. 이에 따라 원전폐기물 고화체에 대한 안정성 평가를 위한 시험법을 선정하기 위하여 아래 그림과 같은 절차에 따라 수행토록 하였다. 우선 대표적인 천층처분 운영국가인 미국과 프랑스의 시험법 그리고 IAEA 권고 시험법과 유사관련 한국 산업표준법들을 조사하고, 이들 시험법들의 주요 차이점을 기술적 관점에서 비교평가하고, 이어서 모의 방사성 및 비방사성 고화체를 이용하여 상기 시험법들을 각각 적용하고 또한 이들 시험법들간의 차이(시험 조건, 시편의 크기 등)에 기인한 상호 비교시험을 통하여 얻어진 시험결과들을 종합적으로 비교 검토하여 보수적 관점에서 시험법을 선정하는 것으로 방향을 잡았다. 이때 시험결과를 얻기 위한 모든 과정에 품질보증 활동을 적용키로 하였으며, 시험결과 분석/평가 과정과 시험법 선정에 각계(규제기관, 학계, 발전소 현장 및 산업계 등) 전문가로부터 기술자문회의를 통하여 자문 의견을 받기로 하였다. 특히 현재 폐기물 인수 기술기준치가 설정된 국가의 시험법을 심층 있게 검토하기로 하였다.검토하기로 하였다.

• Journal of Educational Research in Mathematics
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• v.27 no.3
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• pp.351-373
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• 2017

The meanings of division don't change and rather are connected from whole numbers to rational numbers. In this respect, connecting division of natural numbers, division of fractions, and division of decimal numbers could help for students to study division in meaningful ways. Against this background, the units of division of fractions and division of decimal numbers in fifth grade were redesigned in a way for students to connect meanings of division and procedures of division. The results showed that most students were able to understand the division meanings and build correct expressions. In addition, the students were able to make appropriate division situations when given only division expressions. On the other hand, some students had difficulties in understanding division situations with fractions or decimal numbers and tended to use specific procedures without applying diverse principles. This study is expected to suggest implications for how to connect division throughout mathematics in elementary school.

• Journal for History of Mathematics
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• v.22 no.3
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• pp.187-206
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• 2009

On this study, the historical flow of the notation was briefly examined and the direction of mathematical investigation activity of the content of notation by analogy was explored and teaching learning materials were developed. Diverse mathematical facts were investigated on the basis of decimal system and binary system which are learned in middle school. First, the way of progressing analytic activity with algebraic material was examined. Second, on the basis of the notation which are learned in the first grade of middle school, the definition of the scale of a -notation, -a -notation, $\frac{1}{a}$notation, $\sqrt{a}$-notation was extended by analogy. The result of this study will be expected to establish the curriculum of mathematics and provide teaching and learning with the meaningful current events.

• Journal of Educational Research in Mathematics
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• v.15 no.4
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• pp.375-399
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• 2005

In this article, I identified many points of commonness and differences at)feared in the fraction units of three conspicuous textbooks -McLellan, MiC and Korea. After that, 1 evaluated these results with reference to more general didactics on which each text-book is based. A background theory of Mc-Lellan's textbook was Dewey's experientialism, and that of MiC was Freudenthal's realistic mathematics education. Through this study, I have reached the fact that these three textbooks could not exhibit the phenomenological wholeness of fraction. Driven by measuring number model which is very abstractive, McLellan's text-book is disregarding the lower level context. MiC textbook, driven by real context, is ignoring higher level model which is close to rational number concept. From an excess of formulation and practice of algorithm, Korea's textbook is overlooking the real context. It is necessary that a textbook which would display the phenomenological wholeness of fraction is developed.

• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.297-312
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• 2006

As research on the instruction method of the concept of irrational numbers, this thesis is theoretically based on the Freudenthal's Mathematising Instruction Theory and a conducted case study in order to find an introduction method of irrational numbers. The purpose of this research is to provide practical information about the instruction method ?f irrational numbers. For this, research questions have been chosen as follows: 1. What is the introducing method of irrational numbers based on the Freudenthal's Mathematising Instruction Theory? 2 What are the Characteristics of the teaming process shown in class using introducing instruction of irrational numbers based on the Freudenthal's Mathematising Instruction? For questions 1 and 2, we conducted literature review and case study respectively For the case study, we, as participant observers, videotaped and transcribed the course of classes, collected data such as reports of students' learning activities, information gathered through interviews, and field notes. The result was analyzed from three viewpoints such as the characteristics of problems, the application of mathematical means, and the development levels of irrational numbers concept.

• Journal of Educational Research in Mathematics
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• v.22 no.2
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• pp.163-178
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• 2012

The efforts to represent the numbers based on the decimal system give us fundamental understanding to construct and teach the concept network on the related knowledge of elementary and secondary school mathematics. In the process to represent natural numbers, integers, rational numbers, real numbers as decimal system, we will classify the extended decimal system. Moreover we will obtain the view to classify real numbers. In this paper, we will study the didactical significance of mathematical knowledge, which arise from process to represent real numbers as decimal system, starting from decimal system representation of natural numbers, and provide the theoretical base about the classification of real numbers. This study help math teachers to understand school mathematics in critical inside-measurement and provide the theore tical background of related knowledge. Furthermore, this study provide a clue to construct coherent curriculum and internal connections of related mathematical knowledge.

• Education of Primary School Mathematics
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• v.24 no.2
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• pp.103-114
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• 2021

In this study I recognized the problems with the use of the terms 'quotient' and 'reminder' in the division of decimal and explored ways to improve them. The prior studies and current textbooks critically analyzed because each researcher has different views on the use of the terms 'quotient' and 'reminder' because of the same view of the values in the division calculation. As a result of this study, I proposed to view the result 'q' and 'r' of division of decimals by division algorithms b=a×q+r as 'quotient' and 'reminder', and the amount equal to or smaller to q the problem context as a final 'result value' and the residual value as 'remained value'. It was also proposed that the approximate value represented by rounding the quotient should not be referred to as 'quotient'.