• Education of Primary School Mathematics
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• v.19 no.4
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• pp.277-289
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• 2016

Fraction is one of the concepts which are difficult to elementary school students. So, many researches about fraction were performed in mathematics education research. In special, fraction has so many subordinative concepts-proper fraction, improper fraction, mixed number. We have to concentrate on the conceptual understanding in teaching of fraction. In this case, a mixed number and improper fraction are concepts which can convert respectively. And there are methods that a mixed number and improper fraction can be converted. So, it's needed to analyze the converting methods in textbooks for getting the implication of teaching in this areas. In this study, I analyzed the Korean and foreign's textbooks. I certified the methods-using addition expression, using part-whole model in the textbooks. For the conceptual understanding, I suggested to use the fusion of the various part-whole fraction models and addition expression more than the algorithm in converting between a mixed number and improper fraction. It's reason that the use of models in converting between a mixed number and improper fraction is important for the relational understanding.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.476-478
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• 2000

본 논문에서는 HMM 학습모델을 이용하여 1445단어 음성인식기를 구현하고, 대분류기법을 이용하여 그 성능을 향상시키는 방법에 대하여 연구를 수행하였으며, 속도개선에 중점을 두었다. 속도개선을 위해서 HMM모델에 계층적 대분류 기법을 적용시켰다. HMM의 상태수가 많을수록 속도가 저하된다는 점을 고려하여, 적은 상태수의 HMM모델로 후보를 정하고, 가변적으로 해당하는 상태수의 HMM모델로 목적단어를 인식하는 방법을 제안하였다. 후보를 정하는 방법을 후보수와 특징파라미터의 종류와 수를 고려하여 다양하게 설정, 실험하여 가장 이상적인 경우를 찾아내었다.

• Journal of Educational Research in Mathematics
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• v.24 no.3
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• pp.467-480
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• 2014

Concepts related to the fraction should be taught with formative thinking activities as well as concrete operational activities. Teaching improper fraction should follow the concept of fraction as a relation of two natural numbers. This concept is also important not to be skipped before teaching the fraction such as "4 is a third of 12". Mixed number should be taught as a sum of a natural number and a proper fraction. Fraction as a quotient of a division is a hard concept to be taught since it requires very high abstractive thinking process. Learning the transformation of division into multiplication of fractions should precede that of fraction as a quotient of a division.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.3
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• pp.425-439
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• 2014

The concept of a fraction as division is a core idea which serves as a axiom in the process of a extension of the natural number system to rational number system. Also, it has necessary position in elementary mathematics. Nevertheless, the timing and method of the introduction of this concept in Korean elementary math textbooks is not well established. In this thesis, I suggested a solution of a various topics which is related to this problem, that is, transforming improper fraction to mixed number, the usage of quotient as a term, explaining the algorithm of division of fraction, transforming fraction to decimal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.1
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• pp.32-38
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• 1993

In this paper a effective classification method for character recognition is proposed. The existing classification methods select candidates by comparing an unknown input character, with all the standard patterns based on the similarity measur. The proposed method, however, groups similiar characters together and uses their average distance as representative value of the group. We divided the character region into several sub-region and applied ISODATA algorithm to partial vectors of each sub-region to anstruct appropriate number of groups. After computing the distance between partial feature vector and its mapping group, we could collect all the information of input character ultimately. The proposed method showed improvement in the processing speed and certainty in classification than the existing methods.

• Journal of Educational Research in Mathematics
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• v.22 no.1
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• pp.53-68
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• 2012

This paper investigated the conceptual schemes four children constructed as they related division number sentences to various types of fraction: Proper fractions, improper fractions, and mixed numbers in both contextual and abstract symbolic forms. Methods followed those of the constructivist teaching experiment. Four fifth-grade students from an inner city school in the southwest United States were interviewed eight times: Pre-test clinical interview, six teaching / semi-structured interviews, and a final post-test clinical interview. Results showed that for equal sharing situations, children conceptualized division in two ways: For mixed numbers, division generated a whole number portion of quotient and a fractional portion of quotient. This provided the conceptual basis to see improper fractions as quotients. For proper fractions, they tended to see the quotient as an instance of the multiplicative structure: $a{\times}b=c$ ; $a{\div}c=\frac{1}{b}$ ; $b{\div}c=\frac{1}{a}$. Results suggest that first, facility in recall of multiplication and division fact families and understanding the multiplicative structure must be emphasized before learning fraction division. Second, to facilitate understanding of the multiplicative structure children must be fluent in representing division in the form of number sentences for equal sharing word problems. If not, their reliance on long division hampers their use of syntax and their understanding of divisor and dividend and their relation to the concepts of numerator and denominator.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.4
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• pp.547-574
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• 2017

The purpose of analysis of foreign curriculums and textbooks is to aimed to get the implications for the revision of curriculum, publishment of textbooks and teaching mathematics. In this study, Common Core State Standards and its textbooks was analyzed. The U. S. doesn't have the national mathematics curriculum. So, it can be happen some problems: students' lower mathematical achievement, assessment policy, decision of teaching contents, etc. In 2010, Common Core State Standards was developed by states. Furthermore, The California Department of Education reshaped standards: CA-CCSSM. This study analyzed the contents of fraction in CA-CCSSM and its textbooks. Fraction has many concepts and methods and models in teaching process. This study analyzed the equal parts, introducing fraction concept, the types of fraction, equivalent fractions, comparison of fractions. The conclusions are as follows; The equal parts are the important concept of fraction and introduced in geometry area before teaching of fraction. CA-CCSSM aims to understand a fraction as a number on the number line and represent fractions on a number line diagram. There are some similarity and difference in mixed number, fractions as a division and ratio, equivalent fractions and comparison of fractions between Korean curriculum and textbooks and CA-CCSSM.

• The Korean Journal of Applied Statistics
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• v.12 no.2
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• pp.375-385
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• 1999

본 연구에서는 노동력수요동향조사를 위한 새로운 표본설계를 제시하였다. 새로운 표본설계에서는 전국 통계를 산출하기 위한 전국표본과 지역 특성에 맞는 고용정책 및 직업 훈련 계획 수립 등을 위한 지역통계의 수요에 따라 16개 시·도별, 규모별, 산업대분류별로 오차를 관리할 수 있는 지역표본으로 이원화하여 설계하였으며, 규모별, 산업대분류별로 오차를 관리하는 현행 표본조사의 상대표준오차를 검토하여 규모별, 산업중분류별로 합리적인 오차 관리가 가능하도록 설계하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.315-318
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• 2002

본 논문에서는 한국 미국, 유럽, 일본에서 출원된 디지털TV 기술에 관한 특허를 분석하였다. 먼저 디지털TV 기술의 분류는 대분류 4가지, 중분류 15가지, 소분류 40여가지로 하였으며, 조사 대상 특허 수는 IPC, UPC, G7에 1981년부터 2002년 4월까지 게재된 특허를 중심으로 한국 3,462건, 일본 2,358건, 유럽 1,596건, 미국 3,216건을 추출하였다. 이들 특허들에 관해 본 논문에서는 전체적인 특허 동향을 분석하고, 각국마다 대분류 및 중분류에 따른 특허 현황을 분석함으로서 국내에 취약한 기술부분을 도출하였다.

• Education of Primary School Mathematics
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• v.21 no.2
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• pp.111-130
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• 2018

In this study, I compared and analyzed the contents of Korean, Japanese, Singapore, American, and Finnish textbooks about fraction which is one of the important and difficult concepts in elementary school mathematics. This is aimed to get the implications for meaningful fractional teaching and learning by analyzing the advantages and disadvantages of the methods and time of introducing the concept because fraction has the diversity of the sub-concepts and the introducing methods or process. As a result of the analysis, the fraction was introduced as part-whole(area) in all five countries' textbooks, but the use of number line, conversion between improper fraction and mixed number, whether to deal with part-whole(set) model. Furthermore, there are differences in the methods in obtaining of the equivalent fraction and the order of arrangement in comparison of fraction. Through this analysis, we discussed the reconsideration of the introducing contexts of fractions, the use of number line when introducing fractions, and the problem of segmentation and classification of contents.