• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.693-695
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• 2003

차단기내에서 일어나는 아크철상을 모의하기 위해서는 수학적으로 표현할 수 있어야 한다. 하지만, 아크의 물리적 현상이 대단히 복잡하여 수식화 하기가 쉽지 않을 백만 아니라 논리적으로 이상이 없는 결과를 얻는 일도 쉽지 않다. 특히, 아크를 표현하는 수식에는 많은 경험적 변수 또는 실험결과를 고려하여 조정되어야 할 변수가 존재한다. 그 대표적인 것이 난류 변수(turbulence parameter)와 방사에너지 전달에서의 방사계수(emission coefficient)이다. 본 논문은 차단기가 전류차단 후의 열적회복과정에서, 난류변수에 따른 아크-후 전류(post arc current)를 계산한 결과를 제시한 것이다. 난류변수에 따른 아크의 냉각효과를 검토하고 있으며, 실험결과 비교하여 가장 잘 맞는 난류변수의 값을 제시하고 있다.

• Journal for History of Mathematics
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• v.10 no.1
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• pp.12-18
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• 1997

수학의 각 분야 중에서 선형성을 가지는 부분은 그 이론이 가장 정연하게 처리되나 이것이 선형대수학이라는 학문으로 형성된 것은 최근의 일이며, 더욱이 선형대수는 그 광범위한 응용성으로 인하여 더욱 중요시되게 되었다. 선형대수의 교육적 의의는 함수의 특수한 경우인 선형변환을 다룸으로서 선형성을 지닌 수학의 구조를 쉽게 파악할 수 있다는 것이며 더욱이 해석기하 등에도 쉽게 응용할 수 있게 된다. 본 논문에서는 타인, 쌍곡선, 포물선인 이차곡선을 행렬을 이용하여 표현하고, 좌표축의 회전이동과 평행이동을 통하여 행렬을 대각화하고, 고유치의 부호에 의하여 이차곡선의 변환과 분류를 다루었으며 더불어 곡선의 개형을 알아보았다.

• Journal of Digital Contents Society
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• v.5 no.4
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• pp.289-294
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• 2004

For the purpose of image analysis, we usually take the application method relying on the various mathematical theories. On the respect of image as two variable function one may uses the gradient vector or several type of energy functions induced by the conventional (partial) derivative. We also have used the tangent plane or curvature vector from the concept of differential geometry {**]. However, these mathematical tools my assume that the given function should be sufficiently smoothing enough to depict every local variation continuously. But the real application of these mathematical methods to the natural images or phenomena may occur the ill-posed problem. In this paper, we have defined the weak derivative as a loose form of the derivative so that it my applied to the irregular case with less ill-posed problem.

• School Mathematics
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• v.9 no.2
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• pp.313-326
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• 2007

Recently in algebra curriculum, to recognizes and explains general nile expressing patterns is presented as the one alternative and is emphasized. In the seventh School Mathematic Curriculum regarding 'regularity and function' area, in elementary school curriculum, is guiding pattern activity of various form. But difficulty and problem of students are pointing in study for learning through pattern activity. In this article, emphasizes generalization process through research activity of pictorial/geometric pattern that is introduced much on elementary school mathematic curriculum and investigates various approach and strategy of student's thinking, state of symbolization in generalization process of pictorial/geometric pattern. And discusses generalization of pictorial/geometric pattern, difficulty of symbolization and suggested several proposals for research activity of pictorial/geometric pattern.

• Journal of Educational Research in Mathematics
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• v.21 no.2
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• pp.165-180
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• 2011

Mathematical symbols concisely represent mathematical contents related to terms by describing their mathematical meanings implicitly. All symbols in elementary school mathematics textbooks are stated as to be read so that elementary school students could understand their mathematical meanings. The same is somewhat true as in middle school mathematics textbooks, however it is often the case that some symbols are difficult to be read and understood because their statements are unclear or different. In this study, we analyze problems and suggest implications on teaching and learning mathematics based on the statements and understanding of reading symbols in middle school mathematics textbooks.

• Journal for History of Mathematics
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• v.16 no.4
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• pp.15-32
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• 2003

Since algebra before the 19th century was the study of equations and equations are not differentiated from polynomials because of lack of the equality sign, the algebraic symbolism of polynomials plays very important role for tile history of algebra. We deal with the evolution of literal notations of polynomials in western and eastern worlds, and then compare their history.

• Journal for History of Mathematics
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• v.29 no.2
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• pp.89-102
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• 2016

Lee Sang, one of the representative poets of Korean Modern Poetry, wrote poems which present the existentialistic modernism in the 1920s, the chaotic era of Korean history. The characteristics of his works have been shown by various points of view. This paper especially explored the meaning and feature of mathematical expressions by numbers, symbols and other signs of mathematics in Lee's poems. His poems are composed by scientific and abstract rules in mathematics which are expressed as mathematical symbols. The paper focuses on analyzing seven poems which maximizes mathematical expressions among his poetry. This kind of work would be the one of ways to figure out the features of mathematics through literature.

• Journal of Educational Research in Mathematics
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• v.19 no.1
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• pp.63-80
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• 2009

This paper has a purpose to find out the important points about linguistic factors suited to the assessment purpose and mathematics teaching/learning that a word-problem sentence has to possess. We also examine the degree of understanding of sentence and the perceptive/emotional reactions of students toward two different kinds of word-problem sentences that have same mathematical contents, but different linguistic structures. The objects of this thesis are 124 students from the third to sixth grade in an elementary school. We execute assessment of simple-sentence-word-problem and complex-sentence-word-problem that have same mathematical contexts, but different linguistic structures. Then we have compared and examined their own process of solving the two types word-problems and we make up questionnaire and have an interview with them. The conclusions are as followings: First, simple-sentence-word-problem is more successful to suggest an information for solving a problem than complex one. Second, it is hard to find the strategy for solving a problem in complex-sentence-word-problem than simple one. Third, students think that suggested information and mathematical knowledge are different according to the linguistic structure in the process of perceiving the information after reading a word-problem. Fourth, in spite of same sentence type, the negative mental reaction is showed greatly to complex-sentence-word-problem even before solving a problem.

• Communications of Mathematical Education
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• v.28 no.2
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• pp.219-234
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• 2014

Music and mathematics have a lot of structural similarities. Major and minor triads used importantly in music are in a relationship of inversion in which the sequence of the intervals is reversed, which is equivalent to reflection in mathematics. Geometrical expressions help understand structures in music as well as mathematics, and a diagram that shows tonal relationships in music is called Tonnetz. Relationships of reflection between major and minor triads can easily be understood by using Tonnetz, and also, transpositions can be expressed in translation. This study looks into existing Tonnetz and introduces S-Tonnetz newly formed by a mathematical principle.

• Education of Primary School Mathematics
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• v.14 no.2
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• pp.147-164
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• 2011

The national mathematics curriculum revised in 2007 emphasized students' mathematical communication and the curriculum is currently applied to all grades. In order to promote students' mathematical communication, the teacher needs to understand full implications and apply them to instruction. This study examined how teachers employed mathematical communication in their instruction and how they perceived it. The results showed that teachers had lack of understanding of student-centered instruction and mathematical communication. They also did not use various representation activities and discussion-based activities as expected. The number of students per classroom was reported by teachers as a main barrier to promote mathematical communication, but it did not make substantial differences in practice. Building on the results, this paper included implications for improving teachers' conception of mathematical communication.