• Korean Journal of Child Studies
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• v.13 no.2
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• pp.33-51
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• 1992

The purpose of this study was to investigate activities of kindergarteners in the mathematics corner. The study included an analysis of children's interactions with mathematics materials and of children's peer interactions during mathematics activities. The subjects were 47 children aged three to four and 72 children aged four to five from four classes of two kindergartens in Kwangju. Children's math activities during free play sessions were observed and audiotaped. The data were coded by the categories of children's peer interactions and types of mathematics manipulations. The characteristics of children's peer interactions and materials frequently selected by the subjects were identified. The results indicated that (1) most of the math materials were for passive manipulation that require children to respond according to predetermined conditions like the rules of games, but (2) the materials that children liked to play with were active manipulative materials that require diversity and flexibility of children's thinking and allow several choices for solutions, and (3) children's peer interactions during math activities were categorized into unilateral and reciprocal/collaborative peer interaction type.

• Journal of the Korean School Mathematics Society
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• v.2 no.1
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• pp.93-104
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• 1999

The subject of this study was the graph of relation of direct inverse proportion, linear function and quadratic function in the 1st, 2nd and 3rd grade of current middle school mathematics curriculum. GSP materials were developed to simplify the principle, trait and characteristics of graphs and make them easier to understand. The overall aim of the materials is to improve the effectiveness of teaching and learning through the utilization of enhanced students' practice. Additionally, the use of the GSP will be useful in the development of mere effective materials. The effectiveness of the GSP materials will be as followings. 1. The step by step approach of GSP materials through computer interaction will enhance students motivation and interest in mathematics. 2. By presenting the subject matter simply and in a variety of ways, difficult concepts can be understood without the use of complex mathematical calculation. 3. The GSP program is different from CAI and other software programs. It should be used only after learning how to input and output data.

• School Mathematics
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• v.5 no.3
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• pp.297-314
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• 2003

Mathematics students must appropriate their mathematical knowledge which has the definition and theorem of mathematics, algorithm, reasonable thought, heuristic, and mathematics language, and so on. That is, students should construct, use, and apply their own knowledge during learning. Appropriation of mathematical knowledge is practicable when mathematics language is in charge of many functions that Vygotsky cited. To reach the potential development level with mathematics language, students need the zones that they interact themselves and peers, as well as teacher. On that ground, this study presented the interactional zones of IZPD, ZPP, and ZAD, and modeled mathematics learning. By the case of 2 students, we found that ZPP and ZAD were necessary and important.

• Journal of Elementary Mathematics Education in Korea
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• v.16 no.3
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• pp.427-450
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• 2012

Using representations is essential for students to organize their thinking, to solve problems and to communicate each other. Students express information or situations suggested by problems easily and organize and infer them systematically using representations. Also, teachers are able to comprehend students' levels of understanding and thinking process better through them, and influence their representations. This study was conducted to understand mathematical representations of students uprightly and to seek implications for proper teaching of representations, by analyzing representations of students in mathematical problem solving process and the transformation process of representation via interactions.

• Interaction and multiscale mechanics
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• v.5 no.1
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• pp.13-26
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• 2012

In this paper, the wave propagation in a generalized thermo elastic plate embedded in an elastic medium (Winkler model) is studied based on the Lord-Schulman (LS) and Green-Lindsay (GL) generalized two dimensional theory of thermo elasticity. Two displacement potential functions are introduced to uncouple the equations of motion. The frequency equations that include the interaction between the plate and foundation are obtained by the traction free boundary conditions using the Bessel function solutions. The numerical calculations are carried out for the material Zinc and the computed non-dimensional frequency and attenuation coefficient are plotted as the dispersion curves for the plate with thermally insulated and isothermal boundaries. The wave characteristics are found to be more stable and realistic in the presence of thermal relaxation times and the foundation parameter. A comparison of the results for the case with no thermal effects shows well agreement with those by the membrane theory.

• Bulletin of the Korean Mathematical Society
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• v.55 no.2
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• pp.591-598
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• 2018

This paper is concerned with global existence of weak solutions to the relativistic Vlasov-Klein-Gordon system. The energy of this system is conserved, but the interaction term ${\int}_{{\mathbb{R}}^n}\;{\rho}{\varphi}dx$ in it need not be positive. So far existence of global weak solutions has been established only for small initial data [9, 14]. In two dimensions, this paper shows that the interaction term can be estimated by the kinetic energy to the power of ${\frac{4q-4}{3q-2}}$ for 1 < q < 2. As a consequence, global existence of weak solutions for general initial data is obtained.

• Structural Engineering and Mechanics
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• v.46 no.6
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• pp.827-842
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• 2013

In this paper, the wave propagation in generalized thermo elastic plate immersed in fluid is studied based on the Lord-Shulman (LS) and Green-Lindsay (GL) generalized two dimensional theory of thermo elasticity. Two displacement potential functions are introduced to uncouple the equations of motion. The frequency equations that include the interaction between the plate and fluid are obtained by the perfect-slip boundary conditions using the Bessel function solutions. The numerical calculations are carried out for the material Zinc and the computed non-dimensional frequency, phase velocity and attenuation coefficient are plotted as the dispersion curves for the plate with thermally insulated and isothermal boundaries. The wave characteristics are found to be more stable and realistic in the presence of thermal relaxation times and the fluid interaction.

• Journal of Educational Research in Mathematics
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• v.12 no.1
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• pp.109-124
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• 2002

This study investigated various effects of WBD(web-based discussion) on mathematical communication, interaction and problem solving in the classroom. We developed a web site including BBS and chat room in order to encourage students' mathematical curiosities and self-studies. The web site had been operated for 6 months. Five classes of 1st grade students were selected from an middle school in Daejon. Moreover, we analyzed several cases for interactional behavior and effect. WBD promote dialogue between a teacher and students. Analysis of feed-back from BBS revealed that student's negative attitudes could be changed to positive ones by step-by-step discussions. Moreover, collaborative learning is enhanced by on-line discussion. But the effects of WBD are affected by the character and ability of a student.

• Genomics & Informatics
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• v.14 no.4
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• pp.166-172
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• 2016

Although a large number of genetic variants have been identified to be associated with common diseases through genome-wide association studies, there still exits limitations in explaining the missing heritability. One approach to solving this missing heritability problem is to investigate gene-gene interactions, rather than a single-locus approach. For gene-gene interaction analysis, the multifactor dimensionality reduction (MDR) method has been widely applied, since the constructive induction algorithm of MDR efficiently reduces high-order dimensions into one dimension by classifying multi-level genotypes into high- and low-risk groups. The MDR method has been extended to various phenotypes and has been improved to provide a significance test for gene-gene interactions. In this paper, we propose a simple method, called accelerated failure time (AFT) UM-MDR, in which the idea of a unified model-based MDR is extended to the survival phenotype by incorporating AFT-MDR into the classification step. The proposed AFT UM-MDR method is compared with AFT-MDR through simulation studies, and a short discussion is given.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.364-372
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• 2016

The purpose of this study was to investigate preservice mathematics teachers' perceptions for mathematics digital textbook. To do this, we provided a questionnaire to 52 preservice mathematics teachers and analysed the questionnaires. The questionnaire was investigated using 5 point scale. The results of this study can be summarized as follows. First, the preservice mathematics teachers' perception on effectiveness of mathematics digital textbook was positive. Second, the preservice mathematics teachers' perception on interaction of mathematics digital textbook was normal. Third, the preservice mathematics teachers' perception on interest of mathematics digital textbook was positive. Fourth, the preservice mathematics teachers' perception on students' health of mathematics digital textbook was normal. Fifth, the preservice mathematics teachers' perception on class-management of mathematics digital textbook was normal. Sixth, some preservice mathematics responded that mathematics digital textbook was efficient to teach a function or a geometry, others responded that paper textbook was more efficient to teach a mathematics.