• Journal of the Korean Mathematical Society
• /
• v.47 no.2
• /
• pp.289-297
• /
• 2010

By using as main tool the theory of prime submodules this article is devoted to describing the structure of the minimal prime ideals of the equidimensional symmetric algebra of a finitely generated module.

• Bulletin of the Korean Mathematical Society
• /
• v.51 no.5
• /
• pp.1269-1279
• /
• 2014

The equations arising from the thermoelastic theory are analyzed in a linear approximation. First, we establish the convergence result on the coefficient c. Next, we establish that the solution depends continuously on changes in the coefficient c. The main tool used in this paper is the energy method.

• Kyungpook Mathematical Journal
• /
• v.45 no.4
• /
• pp.549-559
• /
• 2005

Given a non-Haken, non Seifert fibred manifold we describe an algorithm that takes 2 (not necessarily distinct) Heegaard surfaces and produces a complex with certain useful properties (Properties 5.1). Our main tool is Rubinstein and Scharlemann's Cerf theoretic work ([5]).

• Journal of the Korean Mathematical Society
• /
• v.46 no.5
• /
• pp.907-918
• /
• 2009

We extend some results involved the action of the Steenrod operations on monomials and get some corollaries on the hit problem. Then, by multiplying some special matrices, we obtain an efficient tool to compute the action of these operations.

• East Asian mathematical journal
• /
• v.37 no.5
• /
• pp.585-590
• /
• 2021

This paper consider the Jacobian variety of a hyperelliptic curve over a finite field with the formal structure of the mixed type. We present the Newton polygon of the characteristic polynomial of the Frobenius endomorphism of the Jacobian variety. It gives an useful tool for finding the local decomposition of the Jacobian variety into isotypic components.

• East Asian mathematical journal
• /
• v.38 no.5
• /
• pp.611-616
• /
• 2022

This paper considers the Jacobian variety of a hyperelliptic curve over a finite field with mixed symmetric formal type. We present the Newton polygon of the characteristic polynomial of the Frobenius endomorphism of the Jacobian variety. It gives a useful tool for finding the local decomposition of the Jacobian variety into isotypic components.

• Communications of Mathematical Education
• /
• v.36 no.3
• /
• pp.355-372
• /
• 2022

The purpose of this study was to find out whether the Grit test is valid as a test tool for Identification of mathematically gifted elementary students. For this study, we conducted Grit tests, Mathematical Problem Solving Aability Tests, Mathematical Creative Ability Tests, and Mathematically Gifted Behavior Characteristic Tests on 39 ordinary students at Seoul public elementary school and 20 mathematically gifted students at the Education Center for Gifted Education, and analyzed correlation with each test. In addition, we conducted a discriminant analysis to find out how the Grit test can accurately determine the members of the mathematically gifted student group and the ordinary student group. As a result of Pearson's correlation analysis, the Grit test was .521 with the Mathematical Problem Solving Ability Tests, .440 with the Mathematical Creative Ability Tests, and .601 with the Mathematically Gifted Behavior Characteristic Tests, according to significant positive correlation at p<.01. Through this, it can be confirmed that the Grit test has a high official validity as a tool for determining mathematically gifted students. As a result of conducting a discriminant analysis to confirm the classification discrimination ability of the elementary mathematically gifted student group and ordinary student group of the Grit test, Wilk's λ was .799(p<.001). We confirm that the Grit test is a significant variable in determining the mathematically gifted student group and ordinary student group. In addition, 64.4% of the entire group was accurately classified as a result of group classification through discriminant analysis. This shows that the Grit test can be actually used as a test tool to determine mathematically gifted elementary students.

• Research in Mathematical Education
• /
• v.7 no.3
• /
• pp.163-189
• /
• 2003

The purpose of this study is to develop a test, which can be used in creative problem solving ability in mathematics of the mathematically gifted and the regular students. This test tool is composed of three categories; fluency (number of responses), flexibility (number of different kinds of responses), and originality (degree of uniqueness of responses) which are the factors of the creativity. After applying to 462 middle school students, this test was analyzed into item analysis. As a results of item analysis, it turned out to be meaningful (reliability: 0.80, validity: item 1(1.05), item 2(1.10), item 3(0.85), item 4(0.90), item 5(1.08), item difficulty: item 1(-0.22), item 2(-0.41), item 3(0.23), item 4(0.40), item 5(-0.01), item discriminating power: item 1(0.73), item 2(0.73), item 3(0.67), item 4(0.51), item 5(0.56), over the level of a standard basis. This means that the test tool was useful in the test process of creative problem solving ability in mathematics

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.5
• /
• pp.13-20
• /
• 2005

Micro EDM process is generally used for machining microholes, cavities, and three dimensional shapes. For machining micro structures, first of all, micro tool electrode is indispensable and WEDG system is proposed for tool fabrication method. When using WEDG, its machining characteristics are highly affected by many EDM parameters such as applied voltage, current, rotation speed, capacitance, and pulse duration. Therefore, the design of experiment is introduced to fully understand the effect of the EDM parameters on machining tool electrode. And an attempt has been made to develop the mathematical model for predicting the size of the tool electrode by calculating spark distance. The suggested model was verified with experiment and predicted working gap distance is in good accord with the measured value.

• Journal of Korean Institute of Industrial Engineers
• /
• v.27 no.1
• /
• pp.69-88
• /
• 2001

In the zigzag milling operation, an important issue is to design a machining strategy which minimizes the cutting time. An important variable for minimization of cutting time is the tool path length. The tool path is divided into cutting path and non-cutting path. Cutting path can be subdivided into tool path segment and step-over, and non-cutting path can be regarded as the tool retraction. We propose a new method to determine the cutting direction which minimizes the length of tool path in a convex or concave polygonal shape including islands. For the minimization of tool path length, we consider two factors such as step-over and tool retraction. Step-over is defined as the tool path length which is parallel to the boundary edges for machining area and the tool retraction is a non-cutting path for machining any remaining regions. In the determination of cutting direction, we propose a mathematical model and an algorithm which minimizes tool retraction length in complex shapes. With the proposed methods, we can generate a tool path for the minimization of cutting time in a convex or concave polygonal shapes including islands.