• Journal of Educational Research in Mathematics
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• v.15 no.3
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• pp.353-374
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• 2005

Recently, there have been many changes in researches of mathematics education. There is a growing number of researchers who are interested in empirical researches. According to the these changes, there is also an emphasis on methodology of mathematics education. This means that many researchers try to conduct an research using scientific approach. Therefore, new types of research developing mathematics courses recently has evolved as follows: teaching experiment, hypothetical loaming trajectory, design science, developmental research. The aim of this study is to reflect on developmental research in RME and to induce desirable directions for developing our mathematics courses. In order to attain these purposes, the present paper reflects the philosophy of RME, aim, procedure, data collection, data analysis, and justification of developmental research with illustrating a exemplar Based on these reflections, it is discussed that it needs to construct the mathematics curriculum connecting theory and practice in mathematics education, to report the process of developing mathematics courses faithfully, and to develop real mathematics courses after conducting basic developmental researches in order to take scientific app- roaches for developing mathematics courses.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.3
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• pp.641-654
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• 2011

In order to grow students' rational and creative problem-solving ability which is one of the primary goals in mathematics education. students' proper understanding of mathematical concepts, principles, and rules must be backed up as its foundational basis. For the relevant teaching strategies. National Mathematics Curriculum advises that students should be allowed to discover and justify the concepts, principles, and rules by themselves not only through the concrete hands-on activities but also through inquiry-based activities based on the learning topics experienced from the diverse phenomena in their surroundings. Hereby, this paper, firstly, looks into both the meaning and the inductive reasoning process of mathematical principles and rules, secondly, suggest "learning through discovery teaching method" for the proper teaching of the mathematical principles and rules recommended by the National Curriculum, and, thirdly, examines the possible discovery-led teaching strategies using inductive methods with the related matters to be attended to.

• Journal of Educational Research in Mathematics
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• v.20 no.4
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• pp.459-476
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• 2010

The purpose of this study is to suggest a new direction in using LOGO as a gifted education program and to seek an effective approach for LOGO teaching and learning, by analyzing the strategic thinking of mathematically gifted elementary students. This research is exploratory and inquisitive qualitative inquiry, involving observations and analyses of the LOGO Project learning process. Four elementary students were selected and over 12 periods utilizing LOGO programming, data were collected, including screen captures from real learning situations, audio recordings, observation data from lessons involving experiments, and interviews with students. The findings from this research are as follows: First, in LOGO Project Learning, the mathematically gifted elementary students were found to utilize such strategic ways of thinking as inferential thinking in use of prior knowledge and thinking procedures, generalization in use of variables, integrated thinking in use of the integration of various commands, critical thinking involving evaluation of prior commands for problem-solving, progressive thinking involving understanding, and applying the current situation with new viewpoints, and flexible thinking involving the devising of various problem solving skills. Second, the students' debugging in LOGO programming included comparing and constrasting grammatical information of commands, graphic and procedures according to programming types and students' abilities, analytical thinking by breaking down procedures, geometry-analysis reasoning involving analyzing diagrams with errors, visualizing diagrams drawn following procedures, and the empirical reasoning on the relationships between the whole and specifics. In conclusion, the LOGO Project Learning was found to be a program for gifted students set apart from other programs, and an effective way to promote gifted students' higher-level thinking abilities.

• Journal for History of Mathematics
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• v.18 no.2
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• pp.95-106
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• 2005

This paper is investigated conception and methodology of data selection, cleaning, integration, transformation, reduction, selection and application of data mining techniques, and model evaluation during procedure of the knowledge discovery in database (KDD) based on Mathematics. Statistical role and methodology in KDD is studied as branch of Mathematics. Also, we investigate the history, mathematical background, important modeling techniques using statistics and information, practical applied field and entire examples of data mining. Also we study the differences between data mining and statistics.

• School Mathematics
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• v.15 no.1
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• pp.201-219
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• 2013

The purpose of this study was to analyse the belief about mathematics teaching of elementary preservice teachers and mathematics teachers. This study involved 100 respondents from the preservice teachers and 114 respondents from the mathematics teachers. The instruments used in this study consist 15 items of mathematical knowledges and 19 items of mathematical activities. The finding showed that preservice teachers emphasized the conceptual knowledge, whereas mathematics teachers emphasized the procedural knowledge in the mathematical knowledges. And preservice teachers emphasized the knowledge representation, knowledge generation, knowledge deliberation, knowledge communication, whereas mathematics teachers emphasized the use of knowledge(syntax) in the mathematical activities. Finally, even though two groups showed the significant difference in some items, preservice teachers and mathematics teachers emphasized the various mathematical knowledges and mathematical activities.

• Journal of Korea Water Resources Association
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• v.55 no.6
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• pp.405-419
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• 2022

Flood frequency analysis commonly used to design the hydraulic structures to minimize flood damage includes uncertainty. Therefore, the most appropriate design flood within a uncertainty should be selected in the final stage of a hydraulic structure, but related studies were rarely carried out. The total expected cost function introduced into the flood frequency analysis is a new approach for determining the optimal design flood. This procedure has been used as UNCODE (UNcertainty COmpliant DEsign), but the application has not yet been introduced in South Korea. This study introduced the mathematical procedure of UNCODE and calculated the optimal design flood using the annual maximum inflow of hydroelectric dams located in the Bukhan River system and results were compared with that of the existing flood frequency. The parameter uncertainty was considered in the total expected cost function using the Gumbel and the GEV distribution, and the Metropolis-Hastings algorithm was used to sample the parameters. In this study, cost function and damage function were assumed to be a first-order linear function. It was found that the medians of the optimal design flood for 4 Hydroelectric dams, 2 probability distributions, and 2 return periods were calculated to be somewhat larger than the design flood by the existing flood frequency analysis. In the future, it is needed to develop the practical approximated procedure to UNCODE.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.2
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• pp.162-170
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• 1984

대부분의 동적댐퍼들은 주구조물의 진동진폭을 정해진 주파수 변위내에서 최대로 줄이는 것을 목 표로 한다. 그러나 공작기계의 안정성은 시편과 공구사이의 상대변위와 절삭력에 의해 결정되는 전달함수의 최대크기에 의해서보다는 실수부분의 최소치에 의해 결정된다는 것이 잘 알려져 있 다. 본 논문에서는 이 사실에 착안하여 공작기계에서 발생하는 채터를 흡수하기 위한 최적의 댐 퍼를 설계하는 절차를 제시하고 1 자유도로 대표될 수 있는 구조물의 경우에 대하여 구체적인 방 법을 예시하였다. 종래의 최적 댐퍼의 성질을 구하는 방법에 비해 수학적인 절차가 약간 복잡해 지기는 하나 전산기를 이용하여 큰 어려움이 없이 최적의 설계자료를 얻을 수 있다. 댐퍼 질량이 정해졌을 때 감쇠율과 스프링 계수를 변수로 하는 목표함수가 하나의 식으로 유도될 수 없기 때 문 에 간단한 최적화 방법으로 이변수 황금분할법을 사용하였다. 수치적인 예를 통하여 종래의 다른 방법에 의한 결과와 비교하고 제안된 방법론의 타당성을 입증하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.292-293
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• 2015

전력수요의 증가 및 대규모 발전단지의 확장, 송 배전설비 확충의 어려움으로 계통이 복잡해지고 광역 정전 발생의 가능성이 증가하고 있다. 광역 정전 발생 시, 이로 인해 발생할 경제적 손실, 사회전반에 파급될 결과와 영향은 심각한 수준이므로 신속하고 안전한 복구방안의 수립이 중요하다. 또한 신속한 계통복구를 위해 정전 시 복구가능시간을 산정하고, 계통복구절차 방안을 제시하는 것이 중요하다. 우리 나라 계통복구절차를 보면 최초정전상태평가, 발전기상태평가, 계통복구방법 선택, 부하복구를 통한 정전복구 단계로 나눠볼 수 있다. 발전기상태 평가 단계에서 발전기들의 상태를 파악한 후, 기동순서를 결정한다. 본 논문에서는 광역정전 시 발전기 특성을 고려한 전력계통 복구를 위한 수학적 정식화를 하고 향후 연구 방향을 살펴보았다.

• Journal of the Korean School Mathematics Society
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• v.12 no.3
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• pp.291-305
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• 2009

The purpose of this article is to formulate the base that mathematical thinking power can be improved through activating the metacognitive ability of students in the math problem solving process. The guidance material for activating the metacognitive ability was devised based on a body of literature and various studies. Two high school students used it in their math problem solving process. They reported that their own mathematical thinking power was improved in this process. And they showed that the necessary strategies and procedures for math problem solving can be monitored and controled by analyzing their own metacognition in the mathematical thinking process. This result suggests that students' metacognition does play an important role in the mathematical thinking process.

• The Mathematical Education
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• v.52 no.1
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• pp.19-41
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• 2013

What is the foundation of mathematical thinking? Is it logic based symbolic language system? or does it rely more on mental imagery and visuo-spatial abilities? What kind of neural changes happen if someone's mathematical abilities improve through practice? To answer these questions, basic cognitive processes including long term memory, working memory, visuo-spatial perception, number processes are considered through neuropsychological outcomes. Neuronal changes following development and practices are inspected and we can show there are neural networks critical for the mathematical thinking and development: prefrontal-anterior cingulate-parietal network. Through these inquiry, we can infer the answer to our question.