• Journal of Elementary Mathematics Education in Korea
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• v.18 no.2
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• pp.319-339
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• 2014

Recently, the discussion about division and partition of fraction increases in Korea's national curriculum documents. There are varieties of assertions arranging from the opinion that both interpretations are unintelligible to the opinion that both interpretations are intelligible. In this paper, we investigated a possibility that division and partition interpretation of fraction become valid. As a result, it is appeared that division and partition interpretation of fraction can be defined reasonably through expansion of interpretation of natural number. Besides, division and partition interpretation of fraction can be work in activity, such as constructing equation from sentence problem, or such as proving algorithm of fraction division.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.4
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• pp.521-539
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• 2016

The structures of partitive and quotitive division of fractions are dealt with differently, and this led to using partitive division context for helping develop invert-multiply algorithm and quotitive division for common denominator algorithm. This approach is unlikely to provide children with an opportunity to develop an understanding of common structure involved in solving different types of division. In this study, I propose two approaches, measurement approach and isomorphism approach, to develop a unifying understanding of fraction division. From each of two approaches of solving quotitive division based on proportional reasoning, I discuss an idea of constructing a measure space, unit of which is a quantity of divisor, and another idea of constructing an isomorphic relationship between the measure spaces of dividend and divisor. These ideas support invert-multiply algorithm for quotitive as well as partitive division and bring proportional reasoning into the context of fraction division. I also discuss some curriculum issues regarding fraction division and proportion in order to promote the proposed unifying understanding of partitive and quotitive division of fractions.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.3
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• pp.395-411
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• 2013

There are two concepts of division: measurement division and partitive or fair-sharing division. Students are expected to understand comprehensively division algorithm in both contexts. Contents of textbooks and teachers' guidebooks should be suitable for helping students develop comprehensive understanding of algorithm for whole-number division in both contexts. The results of the analysis of textbooks and teachers' guidebooks shows that they fail to connect two division contexts with division algorithm comprehensively. Their expedient and improper use of two division contexts would keep students from developing comprehensive understanding of algorithm for whole-number division. Based on the results of analysis, some ways of improving textbooks and teachers' guidebooks are suggested.

• Education of Primary School Mathematics
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• v.14 no.3
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• pp.317-328
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• 2011

We analyzed errors committed by Korean prospective elementary teachers in finding and interpreting quotient and remainder within measurement division of fractions. 65 prospective elementary teachers were participated in this study. They solved a word problem about measurement division of fractions. We analyzed solutions of all participants, and interviewed 5 participants of them. The results reveal many of these prospective teachers could not tell what fractional part of division result means. Thses results suggest that teacher preparation program should emphasize interpreting calculation results within given situations.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.343-343
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• 2015

고종횡비의 실리콘 관통전극(TSV)은 반도체 3차원 적층을 실현하기 위한 핵심적인 기술이다. TSV의 충전은 주로 전해도금을 이용하는데 무결함 충전을 위해서 도금액에 몇 가지 첨가제(억제제, 가속제, 평탄제)가 포함된다. 본 연구에서는 첨가제 유무 따른 비아 충전 양상 및 무결함 충전에 대한 연구를 진행하였다. 비아 충전 공정을 위해서 직경 10 um, 깊이 50 um의 TSV가 패터닝된 웨이퍼를 준비하였으며 도금 후 단면을 관찰하여 도금의 양상을 비교하였다. 도금액에 첨가제가 포함되지 않는 조건, 억제제와 가속제만 포함된 조건, 세 가지 첨가제가 모두 포함된 조건으로 비아 충전을 실행하였으며 최종적으로 무결함 충전이 되는 첨가제 조건을 찾을 수 있었다.

• 프린팅코리아
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• v.10 no.8
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• pp.124-129
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• 2011

지난 2004년부터 실시된 주 40시간 근무제가 지난 7월 1일부터 5인 이상 사업장으로 확대됐다. 지난 2008년까지는 20인 이상 사업장에 한해 40시간 근무제가 실시됐으나 이번 7월부터는 대부분의 인쇄사 및 관련업체들이 포함되는 5인 이상사업장이 그 대상이 되고 있다. 근로자에는 대표자는 포함되지 않으나 계약직 정규직 4대보험 미신고자 등과 상관없이 모든 근로자들이 포함된다. 40시간 근무제의 확대시행으로 이를 제대로 지키지 않을 경우 근로기준법위반으로 형사처벌을 받을 수도 있다. 이에 본지에서는 40시간 근무제가 무엇이고 인쇄사에서 주의해야 할 점들에 대해 알아본다.

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.4
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• pp.385-403
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• 2018

Fraction division can be categorized as partitive division, measurement division, and the inverse of a Cartesian product. In the contexts of quotitive division and the inverse of a Cartesian product, the multiply-by-the-reciprocal algorithm is drawn well out. In this study, I analyze the potential and significance of the method of using $1{\div}$(divisor) as an alternative way of developing the multiply-by-the-reciprocal algorithm in the context of quotitive division. The method of using $1{\div}$(divisor) in quotitive division has the following advantages. First, by this method we can draw the multiply-by-the-reciprocal algorithm keeping connection with the context of quotitive division. Second, as in other contexts, this method focuses on the multiplicative relationship between the divisor and 1. Third, as in other contexts, this method investigates the multiplicative relationship between the divisor and 1 by two kinds of reasoning that use either ${\frac{1}{the\;denominator\;of\;the\;divisor}}$ or the numerator of the divisor as a stepping stone. These advantages indicates the potential of this method in understanding the multiply-by-the-reciprocal algorithm as the common structure of fraction division. This method is based on the dual meaning of a fraction as a quantity and the composition of times which the current elementary mathematics textbook does not focus on. It is necessary to pay attention to how to form this basis when developing teaching materials for fraction division.

• 환경사랑
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• s.63
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• pp.9-9
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• 2012

2011년 1월 '완구 인형 및 종합제품 EPS포장 사용 금지 규정의 삭제'로 EPS에 대한 규제가 완전 해제됨에 따라 국립농산물품질관리원은 "농산물품질관리법" 제4조 및 동법 시행규칙 제5조의 규정에 의하여 EPS 포장 상자를 포함한 농산물표준규격을 개정 고시(국립농산물품질관리원 고시 제2011-45호, 2011. 12. 21.)하였다.

• Journal of Korea Fair Competition Federation
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• no.131
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• pp.32-36
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• 2007

2007년초 공정거래위원회는 공정거래법 개정안을 입법예고하면서 동의명령제를 포함시켰으나 부처간 협의과정에서 동의명령제 도입 규정이 삭제된 바 있다. 그 이후 3월초 한국과 미국은 한미간의 자유무역협정(FTA)에 동의명령제를 포함시키기로 합의하였기 때문에 앞으로 이의 도입이 불가피하게 되었다. 동의명령제에 대해서는아직 그내용이 널리 알려져 있지 않아서 도입 필요성에 대해서도 이해가 넓지 않은 것 같다. 본 고에서는 동의명령제가 어떤 제도이며. 우리나라에서 왜 동의명령제의 도입이 필요한지를 살펴보겠다.

• School Mathematics
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• v.6 no.3
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• pp.235-249
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• 2004

The purpose of this study was to analyze the error patterns and sentence types in word problems with respect to 1$\frac{3}{4}$$\div$$\frac{1}{2}$ which were made by the pre-service elementary teachers, and to suggest the clues to the education in pre-service. Korean elementary teachers in pre-service misunderstood 'divide with $\frac{1}{2}$' to 'divide to 2' by the Korean linguistic structure. And they showed a new error type of 1$\frac{3}{4}$$\times$2 by the result of calculation. Although they are familiar to 'inclusive algorithm' they are not good at dealing with the fractional divisor. And they are very poor at the 'decision the unit proportion' and the 'inverse of multiplication'. So, it is necessary to teach the meaning of the fractional division as 'decision the unit proportion' and 'inverse of multiplication' and to give several examples with respect to the actual situation and context.