• School Mathematics
• /
• v.11 no.3
• /
• pp.351-368
• /
• 2009

This study presents data from a year-long teaching experiment which illustrate how two seventh graders modified their multiplicative thinking and interacted with their representing symbols in the context of combinatorial problem situations. Damon was at the process of construction of recursively multiplicative thinking by modifying his multiplicative reasoning, but Carol appeared to remain at the stage of a binary multiplicative scheme. The two students' struggles with their representing symbols or represented symbols by the teacher show that even well-organized symbolic systems from teachers' perspective do not necessarily help students advance their mathematical capacity.

• Journal for History of Mathematics
• /
• v.31 no.3
• /
• pp.127-150
• /
• 2018

In spite of important researches and translational works of the Joseon mathematical treatises in the 80's and on, these results were almost out of reach to the school teachers as well as students due to the antiquity of their contents and the terms used. In order to make our traditional mathematics approachable to the middle and high school students, it will be educationally meaningful to reinterpret them tuned at the student's level using modern terminology and symbols. In this study, we reinterpreted 9 problems from Cheukryang Dohae, which is one of the representative mathematical books of Joseon Dynasty. We used the terminology and symbols from the school curriculum. We also reconstructed two of them using modern metrologies adapted to modern situations adding illustrations and photos, so that they are useful at the teaching site.

• Journal of Elementary Mathematics Education in Korea
• /
• v.17 no.2
• /
• pp.207-223
• /
• 2013

Teachers unfold a series of timeless mathematical symbols such as 5+2=7 in time by verbalizing the symbols in classrooms. A number sentence 5+2=7 is read in Korean as '5 더하기 2는(five plus two) 7과(seven) 같다(equals). Unlike in English, 5+2 and 7 are read first before the equal sign in Korean. This sequence of reading in Korean conflicts with the conventional linguistic sequence of writing from left to right. Ways of resolving the discrepancy between reading and writing sequences can make a difference students' understanding of the equal sign. Students would be in danger of perceiving the equal sign as an operational symbol, if a teacher resolves the discrepancy by subordinating reading sequence to linguistic convention of writing. This way of resolving results in the undesired phenomenon of changing the reading expressions in Korean elementary math textbook which represent relational notion of the equal sign into other reading expressions that represent operational notion of it. For understanding of relational notion of the equal sign, the discrepancy should be resolved by changing writing sequence in accordance with reading sequence. In addition, teaching of verbalizing the equal sign should be integrated with teaching of verbalizing inequality signs.

• Journal of applied mathematics & informatics
• /
• v.7 no.2
• /
• pp.665-671
• /
• 2000

A matrix whose entries consist of the symbols +.- and 0 is called a sign pattern matrix . In 1994 , Eschenbach gave a graph theoretic characterization of irreducible sign idempotent pattern matrices. In this paper, we give a characterization of reducible sign idempotent matrices. We show that reducible sign idempotent matrices, whose digraph is contained in an irreducible sign idempotent matrix, has all nonnegative entries up to equivalences. this extend the previous result.

• Journal of the Korean Mathematical Society
• /
• v.61 no.3
• /
• pp.461-494
• /
• 2024

We prove the Sobolev continuity of maximal commutator and its fractional variant with Lipschitz symbols, both in the global and local cases. The main result in global case answers a question originally posed by Liu and Wang in [29].

• Journal for History of Mathematics
• /
• v.16 no.3
• /
• pp.27-44
• /
• 2003

The article is to understand the meaning of numbers on the cuboctahedron which was used in the United Shilla and to find the way to apply it into our current school curriculum. We want to reinterpret the meaning of tile numbers on this cuboctahedron. Also, we introduce this meaning to Symbols and Expressions in the 7th-grade math and expand it to Operations of Polynomials.

• Korean Journal of Mathematics
• /
• v.7 no.2
• /
• pp.271-280
• /
• 1999

We study Toeplitz operators on the harmonic Bergman Space $b^p(\mathbf{H})$, where $\mathbf{H}$ is the upper half space in $\mathbf{R}(n{\geq}2)$, for 1 < $p$ < ${\infty}$. We give characterizations for the Toeplitz operators with positive symbols to be bounded.

• Communications of the Korean Mathematical Society
• /
• v.34 no.2
• /
• pp.533-542
• /
• 2019

We study commutants of Toeplitz operators acting on the Dirichlet space of the unit disk and prove that an operator in the Toeplitz algebra commuting with a Toeplitz operator with a nonconstant polynomial symbol must be a Toeplitz operator with an analytic symbol.

• Bulletin of the Korean Mathematical Society
• /
• v.54 no.6
• /
• pp.2013-2027
• /
• 2017

We compute explicitly the matrices represented by Toeplitz operators on the Hardy space over the unit circle with respect to a special orthonormal basis constructed by author in terms of their symbols. And we also find a necessary condition for the matrix generated by the product of two Toeplitz operators with respect to the basis to be a Toeplitz matrix by a direct calculation and we finally solve commuting problems of two Toeplitz operators in terms of symbols. This is a generalization of the classical results obtained regarding to the orthonormal basis consisting of the monomials.

• Journal for History of Mathematics
• /
• v.28 no.1
• /
• pp.15-29
• /
• 2015

This study aims to analyze how the history of mathematics is used in Chinese mathematics textbooks. As a framework for analysis, we categorized nine types of using the history of mathematics in textbooks. We analyzed 18 mathematics textbooks for Chinese elementary and middle schools. As a result, we found that various types of using the history of mathematics were adopted in Chinese textbooks except for explorations of mathematical errors in history. We also noticed three characteristics: preference to using for motivation and reading matters in elementary school levels, high frequencies of using problems from traditional mathematical books and origins of mathematical concepts or symbols, and emphasis on ethnic superiority through the Chinese traditional mathematics. Based on the results of analysis, we discussed and induced some implications for using the history in our mathematics textbooks.