• East Asian mathematical journal
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• 제30권2호
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• pp.173-195
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• 2014

This study, utilizing several features about plane figures covered in the current secondary curriculum of mathematics and reviewing two solutions to cube duplication problem presented by Menaechmus, proving the solution by Nicomedes and visualizing solutions based on Apollonius' 'Conics' by medieval Islam geometricians such as Ab$\bar{u}$ Bakr al-Haraw$\bar{i}$, AbAb$\bar{u}$ J$\acute{a}$far al-Kh$\bar{a}$zin, Nas$\bar{i}$r al-D$\bar{i}$n al-T$\bar{u}s\bar{i}$, Y$\bar{u}$suf al-Mu'taman ibn H$\bar{u}$d, introduce to teachers and students in the field where the question of cube duplication problem comes from and which solving method has developed it and suggests new methods for visualization using dynamic geometry program as well so that the contents reviewed can be used in the filed. The solving methods to cube duplication problem in this paper are very creative and increase the practicality, efficiency and value of Mathematics, and provide students and teachers with the opportunities to reconfirm the importance and beauty of basic knowledge in the secondary geometry in the process of visualization of drawing figures using dynamic geometry program.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제14권3호
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• pp.277-291
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• 2011

수학수업을 통해서 학생들에게 기대되는 학습 목표를 제대로 구현하기 위해서는 무엇보다 수학을 왜 가르치고 배워야 하는지에 대한 교사의 올바른 인식이 필수적이다. 이에 본 연구에서는 초등학교 교사들이 수학교육의 목적을 어떻게 인식하고 있는지 설문 조사를 실시하였다. 연구결과 교사들은 합리적 논리적 사고 발달, 실용성, 도구 교과로서 수학을 인식하는 비중이 높은 반면에 세계에 대한 이해, 심미성, 의사소통 및 사회성 발달로서의 수학을 인식하는 비중은 상대적으로 낮았다. 한편 학문적 가치와 관련해서는 교사가 직접 서술한 수학학습의 이유에는 별반 나타나지 않은 반면에 리커트 척도에 의한 응답에서는 높게 나타나는 특징이 있었다. 교사의 인식은 성별에 따라서 통계적으로 유의미한 차이는 없었으나 5년 미만의 교육경력을 가진 교사가 그렇지 않은 교사집단에 비해 대체적으로 수학교육 목적을 긍정하는 비율이 낮았다. 이와 같은 연구 결과를 토대로 본 논문에서는 교사의 수학교육목적 인식에 따른 시사점을 살펴보았다.

• Structural Engineering and Mechanics
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• 제70권5호
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• pp.639-647
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• 2019

The performance of precast concrete structures is greatly influenced by the behaviour of beam-to-column connections. A single connection may be required to transfer several loads simultaneously so each one of those loads must be considered in the design. A good connection combines practicality and economy, which requires an understanding of several factors; including strength, serviceability, erection and economics. This research work focuses on the performance aspect of a specific type of beam-to-column connection using partly hidden corbel in precast concrete structures. In this study, the results of experimental assessment of the proposed beam-to-column connection in precast concrete frames was used. The purpose of this research is to develop and apply the Extreme Learning Machine (ELM) for moment-rotation prediction of precast beam-to-column connections. The ELM results are compared with genetic programming (GP) and artificial neural network (ANN). The reliability of the computational models was accessed based on simulation results and using several statistical indicators.

• 한국수학사학회지
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• 제31권5호
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• pp.251-269
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• 2018

Empirical probability and classical probability, which are two interpretations of Kolmogorov's axiom, are two ways to recognize the chances of events occurring in the real world. In this paper, I analyzed and suggested the contents of the high school textbooks ${\ll}$Probability and Statistics${\gg}$, associated with two interpretations of probability and experiments on which two interpretations are based. By presenting the cases required expressly stating what the experiment is for supporting students' understanding of some concepts, it was discussed that stating or not stating what the experiment is should be carefully determined by the educational intent. Especially, I suggested that in the textbooks we contrast the good idea of calculating the ratios of two possibilities in the imaginary world of the classical probability with the normal idea of grasping the chances of events through the frequencies in the real world of the empirical probability, with distinguishing the experiments in two interpretations of probability. I also suggested that in the textbooks we make it clear that the Weak Law of Large Numbers justifies our expectations of the frequencies' reflecting the chances of events occurring in the real world under ideal conditions. Teaching and learning about the aesthetic elements and the practicality of imaginary mathematical thinking supported by these textbooks statements could be one form of Humanities education in mathematics as STEAM education.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2004년도 춘계학술대회
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• pp.91-101
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• 2004

The turbulent flow is of fundamental interest because the conservation equations for thermodynamics, mass and momentum are linked together. This turbulent flow consists of some coherent time- and space-organized vortical structures. Research has already shown that some dynamic systems and experimental models still cannot provide a good nonlinear analysis of turbulent time series. In the real turbulent flow, very complicated nonlinear behaviors, which are affected by many vague factors are present. In this paper, a kernel-based machine for fuzzy nonlinear regression analysis is proposed to predict the nonlinear time series of turbulent flows. In order to show the practicality and usefulness of this model, we present an example of predicting the near-wall turbulence time series as a verifiable model and compare with fuzzy piecewise regression. The results of practical applications show that the proposed method is appropriate and appears to be useful in nonlinear analysis and in fuzzy environments to predict the turbulence time series.

• 대한수학회지
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• 제52권4호
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• pp.797-819
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• 2015

A trapdoor discrete logarithm group is a cryptographic primitive with many applications, and an algorithm that allows discrete logarithm problems to be solved faster using a pre-computed table increases the practicality of using this primitive. Currently, the distinguished point method and one extension to this algorithm are the only pre-computation aided discrete logarithm problem solving algorithms appearing in the related literature. This work investigates the possibility of adopting other pre-computation matrix structures that were originally designed for used with cryptanalytic time memory tradeoff algorithms to work as pre-computation aided discrete logarithm problem solving algorithms. We find that the classical Hellman matrix structure leads to an algorithm that has performance advantages over the two existing algorithms.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제15권1호
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• pp.31-40
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• 2012

본 연구는 영재 교수 학습 과정에서 초동영재학생들에게 자기주도적 발견식 탐구식 학습을 실시하여 학습의 효과를 높이고, 수학적 원리와 수학의 심미성을 갖는 창의적인 산출물을 생산해 낼 수 있는 교수 학습 모형을 개발하고, 개발한 모형으로 수업을 진행한 후 나타난 특징에 대하여 탐구하였다. 그 결과 다음과 같은 결론을 얻었다. 첫째, 개발된 영재 교수 학습 모형은 초등수학 영재학생들에게 자료를 통찰하는 능력과 분석적 연역적 추론 능력과 같은 수학적 창의성을 발현하게 한다. 둘째, GSP를 활용한 원형 디자인은 초등수학 영재학생들에게 수학적 패턴을 시각적으로 표현함으로써 추상화된 규칙을 인식하는데 도움을 준다. 셋째, 자연수의 연산을 활용한 원형 디자인은 초등수학 영재학생들의 수학에 대한 심미성과 창의성을 발현하는데 긍정적인 영향을 준다.

• 대한수학교육학회지:수학교육학연구
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• 제9권1호
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• pp.217-228
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• 1999

The fundamental theorem of calculus is the most 'fundamental' content in teaching calculus. Since the aim of teaching the theorem goes beyond simple application of it, it is difficult to teach it meaningfully. Hence, for the meaningful teaching of the fundamental theorem of calculus, this article seeks to find the educational implication of the fundamental theorem of calculus through reviewing the genetic history of it. A genetic history of the fundamental theorem of calculus can be divided into the following five phases: 1. The deductive discovery of the fundamental theorem of calculus 2. Galileo's Law of falling body and the idea of the fundamental theorem of calculus 3. The discovery of the fundamental theorem of calculus and Barrow's proof 4. Newton's mensuration 5. the development of calculus in 19th century and the fundamental theorem of calculus The developmental phases of the fundamental theorem of calculus discussed above provides the three educational implications. first, we can rediscover this theorem through deductive methods and get the ideas of it in relation to kinetic problems. Second, the developmental phases of the fundamental theorem of calculus shows that the value of this theorem lies in the harmony of its theoretical beauty and practicality. Third, Newton's dynamic image of this theorem can be a typical way of understanding the theorem. We have different aims of teaching the fundamental theorem of calculus, according to which the teaching methods can be adopted. But it is self-evident that the simple application of the theorem is just a part of teaching the fundamental theorem of calculus. Hence we must try to put the educational implications reviewed above into practice.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제17권2호
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• pp.113-125
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• 2014

본 연구의 목적은 초등학교 6학년 학생들의 그래프 해석이 어떠한지를 살펴보고, 이를 토대로 그래프 해석 능력을 향상시킬 수 있는 지도 방안을 모색하는 데 있다. 연구문제 해결을 위하여 그래프 해석 검사 결과를 분석하고 그래프 해석 지도 방안을 마련하여 적용하였다. 이를 통해 학생들은 그래프를 해석할 때 양적인면과 질적인 면을 종합적으로 볼 수 있게 되었으며, 그래프와 실생활을 관련지어 생각하면서 그래프의 실용성을 체득하게 되었다. 이를 토대로 학생들의 그래프 해석능력을 향상 시킬 수 있도록 지도 방안을 개선하는데 도움이 될 수 있을 것이다.

• Computers and Concrete
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• 제25권1호
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• pp.15-27
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• 2020

During the past decades, the application of acoustic emission techniques (AET) through the diagnosis and monitoring of the fracture process in materials has been attracting considerable attention. AET proved to be operative among the other non-destructive testing methods for various reasons including their practicality and cost-effectiveness. Concrete and rock structures often demand thorough and real-time assessment to predict and prevent their damage nucleation and evolution. This paper presents an overview of the work carried out on the use of AE as a monitoring technique to form a comprehensive insight into its potential application in brittle materials. Reported properties in this study are crack growth behavior, localization, damage evolution, dynamic character and structures monitoring. This literature review provides practicing engineers and researchers with the main AE procedures to follow when examining the possibility of failure in civil/resource structures that rely on brittle materials.