• Journal of the Korean School Mathematics Society
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• v.12 no.2
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• pp.281-308
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• 2009

In the process of solving a linear equation, some questions had equal sign('=') relation properly, while other questions did not have equal sign('=') relation properly. Since whether students could express equal sign('=') relation properly or not is determined by questions, the direction for teaching should be instituted, and instruction and teaching should be conducted by comparing and analyzing after conducing tests on may items. Most of students who got the answer for items without the method of solving a linear equation solved the items using binomial. For questions asking to solve using the characteristic of equality, most of students solved the questions using binomial instead of using the characteristic of equality. Therefore, instruction and learning to solve equations using both the characteristic of equality and binomial have to be achieved.

• Communications of Mathematical Education
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• v.20 no.3 s.27
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• pp.373-389
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• 2006

The purpose of this study is to compare the way of proving using combinational proof with the way of proving presented in the existing math textbook in the proof of combinational equation and to classify the problem-solving into some categories using combinational proof in combinational equation. Corresponding with these, this study suggests the application of combinational equation using combinational proof and the fundamental material to develop material for advanced study.

• Communications of Mathematical Education
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• v.22 no.1
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• pp.53-63
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• 2008

In this paper we study a new proof method of equalities and inequalities using moment of inertia. We analyze proof method using moment of inertia, and describe how to prove equalities and inequalities using moment of inertia.

• Journal of the Korean School Mathematics Society
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• v.10 no.4
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• pp.519-533
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• 2007

In this paper we study a equality $\frac{1}{h_a}+\frac{1}{h_b}+\frac{1}{h_c}=\frac{1}{r}$ which contains altitudes and radius of inscribed circle of triangle. We search some paths for proving the equality, and find out 9 proof method of the equality which is related with descriptive geometry, coordinate geometry, and vector geometry.

• Communications of Mathematical Education
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• v.24 no.3
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• pp.543-562
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• 2010

The purpose of this thesis is to analyze the error happening in the process of solving the simultaneous inequality with two unknown qualities and to propose the correct teaching method. We first introduce a problem about the simultaneous inequality with two unknown qualities. And we will see the solution which a student offers. Finally we propose the correct teaching method by analyzing the error happening in the process of solving the simultaneous inequality with two unknown qualities. The cause of the error are a wrong conception which started with the process of solving the simultaneous equality with two unknown qualities and an insufficient curriculum in connection with the simultaneous inequality with two unknown qualities. Especially we can find out the problem that the students don't look the interrelation between two valuables when they solve the simultaneous inequality with two unknown qualities. Therefore we insist that we must teach students looking the interrelation between two valuables when they solve the simultaneous inequality with two unknown qualities.

• Education of Primary School Mathematics
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• v.27 no.1
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• pp.39-55
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• 2024

Recently, the 2022 revised mathematics curriculum has established achievement standards for equal sign and equality, and efforts have been made to examine teaching methods and student understanding of relational understanding of equal sign. In this context, this study conducted a lesson that emphasized relational understanding in an introduction to equal sign, and compared and analyzed the understanding of equal sign between the experimental group, which participated in the lesson emphasizing relational understanding and the control group, which participated in the standard lesson. For this purpose, two classes of students participated in this study, and the results were analyzed by administering pre- and post-tests on the understanding of equal sign. The results showed that students in the experimental group had significantly higher average scores than students in the control group in all areas of equation-structure, equal sign-definition, and equation-solving. In addition, when comparing the means of students by item, we found that there was a significant difference between the means of the control group and the experimental group in the items dealing with equal sign in the structure of 'a=b' and 'a+b=c+d', and that most of the students in the experimental group correctly answered 'sameness' as the meaning of equal sign, but there were still many responses that interpreted the equal sign as 'answer'. Based on these results, we discussed the implications for instruction that emphasizes relational understanding in equal sign introduction lessons.

• The Mathematical Education
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• v.61 no.1
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• pp.109-126
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• 2022

The purpose of this study is to explore how well teachers anticipate students to understand and solve equations. For this purpose, a questionnaire of the equal sign was developed, and 20 fourth-grade classes were selected as research participants. Teachers in each class were asked to predict various strategies on how their own students would respond to the questionnaire, and a total of 450 students from the 20 classes solved the questionnaire. As a result of the analysis, the teachers could predict students' computational strategies and relational strategies easily but did not fully understand that some students used both strategies or employed incorrect computational or relational strategies. The students tended to use relational strategies better than the teachers expected. They also employed operational strategies more often than the teachers expected. The teachers predicted that students' strategies would be influenced by the types of the problems such as equation-structure items and equation-solving items, whereas the students were more influenced by the forms of equations in the problems. Based on these results, several implications for the knowledge to which teachers needed to attend were discussed so that elementary school students could enhance the relational understanding of the equal sign.

• The Science & Technology
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• v.29 no.4 s.323
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• pp.76-77
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• 1996

포항공대 최재경교수는 미분기하학으로 박사학위를 받은 후 등주부등식을 연구해온 세계적 수준의 수학자다. 그는 1988년 곡면의 경계가 두개일때 등주부등식이 성립함을 사상 처음으로 증명했다. 이러한 연구결과는 지난 70년동안 수학자들이 해결하지 못했던 주목할만한 연구결과로 높게 평가받고 있다.

• Journal of Educational Research in Mathematics
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• v.26 no.1
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• pp.79-101
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• 2016

Understanding the equal sign is of great significance to the development of algebraic thinking. Given this importance, this study investigated in what ways a total of 695 students from second to sixth graders understand the equal sign. The results showed that students were successful in solving standard problems whereas they were poor at items demanding high relational thinking. It was noticeable that some of the students were based on computational thinking rather than relational understanding of the equal sign. The students had a difficulty both in understanding the structure of equations and in solving equations in non-standard problem contexts. They also had incomplete understanding of the equal sign. This paper is expected to explore the understanding of the equal sign by elementary school students in multiple problem contexts and to provide implications of how to promote students' understanding of the equal sign.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.419-424
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• 2010

Through the process of state estimation in the electric railway substation, this paper presents a new method for improving the reliability of the measurements corrupted by gauge error. Unlike the case of commercial power systems, it has been difficult to perform the state estimation by using the usual methods in the electric railway substation. At some of the monitoring points in the substation, most often, it is hard to define the measurement functions by use of the states or as we set up a new states set with the change of system topology, some of the measurement functions become part of the states themselves, which leads to poor results. To resolve the problems in the existing method caused by the relations between the states and the measurement functions at the monitoring points, the proposed method in this paper exploits the equality constraints. They can be derived numerously and concisely from the current and the voltage attributes of the Scott transformer and the buses connecting conditions, etc. We have proofed the effectiveness of the proposed method by the test on a standard sample substation.