• Communications of Mathematical Education
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• v.28 no.4
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• pp.529-552
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• 2014

Recently, mathematical reasoning has been considered as one of the most important mathematical thinking abilities to be established in school mathematics. This study is to investigate the mathematical problems on the content of 'Set and Statement' and 'Sequences' in high school according to the four types of reasoning, namely Making Conjectures, Investigating Conjectures, Developing Arguments, and Evaluating Arguments. Those types of reasoning were reconstructed based on Johnson's six types of reasoning suggested in 2010. The content is dealt with in 'Mathematics II' textbook developed and published according to the mathematics curriculum revised in 2009. The subject of this study is nine types of textbooks and mathematical problems in the textbook are consisted of as two parts of 'general problem' and 'evaluation problem'. Finally, the results of this study can be summarized as follow: First, it is stated that students be establishing a logical justification activity, the highest reasoning activity through dealing with the 'Developing Arguments' type of problems affluently in both 'Set and Statement' and 'Sequence' chapters of Mathematics II textbook. Second, it is mentioned that students have an chance to investigate conjectures and develop logical arguments in 'Set and Statement' chapter of Mathematics II textbook. In particular, whereas they have an chance to investigate conjectures and also develop arguments in 'Statement', the 'Set' chapter is given only an opportunity of developing arguments. Third, students are offered on an opportunity of reasoning that can make conjectures and develop logical arguments in 'Sequences' chapter of Mathematics II textbook. Fourth, Mathematics II textbook are geared to do activities that could evaluate arguments while dealing with the problems relevant to 'mathematical process' included in 'general problem'.

• Journal of Elementary Mathematics Education in Korea
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• v.24 no.1
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• pp.169-186
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• 2020

The purpose of this study is to find new material for developing teaching and learning materials for the gifted class of elementary school students by using the rotatable tangram made by modifying the traditional tangram. Rotatable tangram can be justified by gifted students through mathematical communication. However, even gifted class students have some limitations in finding and justifying triangles and rectangles of all sizes unless they go through the 'symbolization' stage at the elementary school level. Therefore, students who need an inquiry process for letters and symbols need to provide supplementary learning materials and additional questions. It is expected that the material of rotatable tangram for the development of teaching and learning materials for elementary school gifted students will contribute to the development of mathematical reasoning and mathematical communication ability.

• Education of Primary School Mathematics
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• v.27 no.2
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• pp.155-171
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• 2024

This study compared and analyzed students' reasoning processes and justification methods when introducing the concept of "the sum of angles in a triangle" in mathematics classes with a focus on both measurement and geometric aspects. To confirm this, the research was conducted in a 4th-grade class at H Elementary School in Suwon, Gyeonggi-do, South Korea. The conclusions drawn from this study are as follows. First, there is a significant difference when introducing "the sum of angles in a triangle" in mathematics classes from a measurement perspective compared to a geometric perspective. Second, justifying the statement "the sum of angles in a triangle is 180°" is more effective when explained through a measurement approach, such as "adding the sizes of the three angles gives 180°," rather than a geometric approach, such as "the sum of the angles forms a straight angle." Since elementary students understand mathematical knowledge through manipulative activities, the level of activity is connected to the quality of mathematics learning. Research on this reasoning process will serve as foundational material for approaching the concept of "the sum of angles in a triangle" within the "Geometry and Measurement" domain of the Revised 2022 curriculum.

• Journal of Elementary Mathematics Education in Korea
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• v.8 no.1
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• pp.1-21
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• 2004

The purpose of this study is analyzing phenomenon of mathematical communication by students applied story shell. Also, this study is obtained teaching indicated in early standardized mathematics classes. It is served we realize the purpose of study and set study subject to be as follows. First, it finds out how to be described activities of students' mathematical communication in the mathematics class applied story shell. Second, it finds out what phenomenon is observed in a behavior side of the mathematics class applied story shell. It is developed 7 story shells for the 6th grade of the elementary school for about 4 months and when applying mathematics classes, it is analyzed the notes and recorded data to get in an each class and when applying mathematics classes. It is analyzed the notes and recorded data to get in an each class. The result of this study is as follows: First, in a mathematics class which applies story shell, students concentrate on the class when hearing and reading mathematics problem. So, they are able to understand a mathematical language included in the problem. Second, in a mathematics class which applies story shell, students participate actively at the mathematics class. And in complicate situation among the students it is served they justify own opinion and persuaded logically. The point which study hints to see such a result is as follows: First, in a mathematics class which applies story shell students have answered more quickly than the old times as hearing and reading the problem in a picture. Second, in a mathematics class which applies story shell, students were used to being the mathematics language intimately and there was to observe to express it by an equation. Third, in a mathematics class which applies story shell students attend to study activity with interest. Forth, in situation of complicate thought, students are persuading and explaining their opinions for the purpose of justification.

• The Mathematical Education
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• v.61 no.1
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• pp.47-62
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• 2022

This study investigated the contents related to the plane figures in the geometry domains of Joseon-Sanhak in the late 18th century and focused on changes in explanations and calculation methods related to plane figures, the rigor of mathematical logic in the problem-solving process, and the newly emerged mathematical topics. For this purpose, We analyzed , and written in the late 18th century and and written in the previous period. The results of this study are as follows. First, an explanation that pays attention to the figures as an object of inquiry, not as a measurement object, and a case of additional presentation or replacing the existing solution method was found. Second, descriptions of the validity of calculations in some problems, explanations through diagrams with figure diagrams, clear perceptions of approximations and explanations of more precise approximation were representative examples of pursuing the rigor of mathematical logic. Lastly, the new geometric domain theme in the late 18th century was Palsun corresponding to today's trigonometric functions and example of extending the relationship between the components of the triangle to a general triangle. Joseon-Sanhak cases in the late 18th century are the meaningful materials which explain the gradual acceptance of the theoretical and argumentative style of Western mathematics

• Applied Biological Chemistry
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• v.20 no.3
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• pp.279-284
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• 1977

Like that mentioned in the 2nd report, because of panel's sense of psychological and physiological responsibility caused by multi-samples, great errors in experimental results are expected. So as to cut down these errors, the new method called "Pair Comparision with Standard" that reduces test frequency and is superior in detecting power is designed, and its mathematical model is proposed. This paper suggests that this method can be used for screening test that, first of all, selects 4-5 of multi-samples and the most efficient sensory evaluation method in laboratorial quality study is that, after screening by this method, Trio Paired Comparison for the final justification is applicated.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.5
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• pp.389-396
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• 2016

The theory of Fourier heat conduction predicts accurately the temperature profiles of a system in a non-equilibrium steady state. However, in the case of transient states at the nanoscale, its applicability is significantly limited. The limitation of the classical Fourier's theory was overcome by C. Cattaneo and P. Vernotte who developed the theory of non-Fourier heat conduction in 1958. Although this new theory has been used in various thermal science areas, it requires considerable mathematical skills for calculating analytical solutions. The aim of this study was the identification of a newer and a simpler type of solution for the hyperbolic partial differential equations of the non-Fourier heat conduction. This constitutes the first trial in a series of planned studies. By inspecting each term included in the proposed solution, the theoretical feasibility of the solution was achieved. The new analytical solution for the non-Fourier heat conduction is a simple exponential function that is compared to the existing data for justification. Although the proposed solution partially satisfies the Cattaneo-Vernotte equation, it cannot simulate a thermal wave behavior. However, the results of this study indicate that it is possible to obtain the theoretical solution of the Cattaneo-Vernotte equation by improving the form of the proposed solution.

• Journal of the Korean Wood Science and Technology
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• v.49 no.3
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• pp.254-266
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• 2021

Using forest resources involves solving complex and diverse tasks. At the same time, one of the key goals in the field is improving the quality of forest infrastructure. This direction requires adequate mathematical and economic justification. Moreover, creating an effective infrastructure will not only increase the accessibility and usage volumes of wood and other forest resources, but also contribute to the development of continuous and sustainable forest management. The existing practice of making decisions in terms of the organizational and technological aspects of logging, based on the personal experiences of managers or leading specialists in enterprises, hinders the achievement of constant optimal efficiency. The paper presents results that are a continuation of the research cycle of the authors' team in the fields of optimization and algorithmization of various logging processes. The focus of the study lies in the processing and movement of wood resources, the most valuable products of the investigated groups of enterprises. To this end, the paper presents a developed algorithm for determining an effective technological chain of transportation in logging operations, and for improving loading and unloading processing operations under dynamic natural and production conditions. This algorithm serves as the methodological basis for designing logging infrastructure in a dynamically changing environment.

• Education of Primary School Mathematics
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• v.27 no.2
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• pp.187-198
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• 2024

The addition and subtraction relationship and the multiplication and division relationship are explicitly dealt with in second and third grade mathematics textbooks. However, these relationships are not discussed anymore in the problem situations and activities in the 4th, 5th, and 6th grade mathematics textbooks. In this study, we investigate the calculation principles of subtraction and division in the elementary school mathematics textbooks. Based on our investigation, we justify the addition and subtraction relationship and the multiplication and division relationship at the level of children's understanding so that we discuss some problem situations and activities where the relationships can be applied to subtraction and division. In addition, we suggest educational implications that can be obtained from children's applying the relationships and the properties of equations to subtraction and division.

• Journal of Gifted/Talented Education
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• v.27 no.1
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• pp.37-57
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• 2017

In terms of making more various geometrical figures than existing Tangram, Sphinx Puzzle has been used as a material for the gifted education. The main research subject of this paper is to verify how many convex polygons can be made by all pieces of a Sphinx Puzzle. There are several previous researches which dealt with this research subject, but they did not account for the clear reasons on the elementary level. In this thesis, I suggest using unit area and minimum area which can be proved on the elementary levels to account for this research subject. Also, I composed the program for the mathematically gifted elementary students, regarding the subject. I figured out whether they can make the mathematical justifications. I applied this program for three 6th grade students who are in the gifted class of the G district office of education. As a consequence, I found that it is possible for some mathematically gifted elementary students to justify that the number of convex polygons that can be made by a Sphinx Puzzle is at best 27 on elementary level.