• Journal for History of Mathematics
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• v.22 no.1
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• pp.89-110
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• 2009

This paper observed the effect of CAS calculator usage while studying algebra on the achievement of low-achievement students. Participants were composed of 70 low-achievement tenth grade students from a high school located in a metropolitan city. That had never used a mathematics educational calculator before. Target participants were divided into two groups: an experiment group that studied activity papers with the aid of a CAS calculator, and a control group that studied the same activity papers using only paper-and-pencil. The content of the activity papers for the two groups was the same, but the structure differed. Content consisted of numbers and operations, equations and inequalities(character and expressions), and functions. Students in the experiment group exhibited matacognition learning using a CAS calculator. The two groups completed mathematics achievement tests both before and after the activity papers. Therefore, ANCOVA analysis results showed that compared to the pretest, results of the experiment group improved considerably more than the control group.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.3
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• pp.479-498
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• 2016

Time is important in children's lives since their preschool years. However, previous studies indicate that many children struggle with the acquisition of time concepts. Also teachers do not know how to help them. This study aims to investigate elementary school students' understanding about time and induce its educational implications. To do this, about 130 children from first to fifth grades were tested for their ability to recognize(read and record) the analogue and digital times and to solve elapsed-time problems. The results showed that even first graders were able to read and record the minute times on digital clocks. And second graders were able to read and record the minute times on analogue clocks. Therefore, the ability to recognize analogue times was mastered by second grade. In case of the elapsed-time problems, there was statistically significant difference according to school years or types of problems. Students were successful in solving simple problems. However, the problems that include regrouping hour and minute remained difficult even for the older children. Based on these results, we made a few suggestions for teaching practice about time.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.374-384
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• 1995

The mathematical adjoint solution of the Analytic Function Expansion (AFEN) method is found by solving the transposed matrix equation of AFEN nodal equation with only minor modification to the forward solution code AFEN. The perturbation calculations are then performed to estimate the change of reactivity by using the mathematical adjoint The adjoint calculational scheme in this study does not require the knowledge of the physical adjoint or the eigenvalue of the forward equation. Using the adjoint solutions, the exact and first-order perturbation calculations are peformed for the well-known benchmark problems (i.e., IAEA-2D benchmark problem and EPRI-9R benchmark problem). The results show that the mathematical adjoint flux calculated in the code is the correct adjoint solution of the AFEN method.

• Communications of Mathematical Education
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• v.35 no.4
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• pp.505-525
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• 2021

In this study, we investigated how multiplication by 2-digit numbers had been taught in elementary mathematics textbooks of Korea, Japan, Singapore, and USA. As a result of analysis, we found as follows. Korean textbooks do not teach the multiplication by 10 and the multiplication by power of 10, but Japanese, Singapore, and US textbooks explicitly teach related content. In the '×tens' teaching, Japanese and American textbooks teach formally the law of association of multiplication applied in the process of calculating the partial product of multiplication. The standard multiplication algorithm generally followed a standard method of recording partial product result according to the law of distribution, but the differences were confirmed in the multiplication model, the teaching method of the law of distribution, and the notation of the last digit '0'. Based upon these results, we suggested some proposals for improving the multiplication teaching.

• Korean Journal of Logic
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• v.5 no.2
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• pp.67-91
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• 2002

모순에 대한 비트겐슈타인의 견해는 매우 특이할 뿐만 아니라 여러 논란을 불러일으키기에 충분하다. 예컨대 그에 따르면 모순이 수학체계에 존재한다 해도 해로울 것이 전혀 없다. 튜링은 이러한 비트겐슈타인의 견해에 대해서, 만일 수학체계에 모순이 있다면, "그 적용의 경우에 다리가 붕괴될 수도 있다"고 공격한다. 반면에 비트겐슈타인은 "모순 때문에 다리가 붕괴될 수도 있다고 말하는 것은 아주 옳은 소리로 들리지 않는다"라고 응수한다. 과연 유모순적인 계산체계로 건설된 다리는 무너질 것인가? 이 물음을 "튜링의 물음"이라고 부르고, 유모순적인 계산체계로 건설된 다리를 간단히 "튜링의 다리"라고 부르기로 하자. 이 글에서는 바로 이 튜링의 물음에 직접 대답하기 위해서 4개의 입론이 제시되고 있다. 우리는 이러한 입론을 토대로 해서 튜링의 물음에 대해 대답할 수 있고, 비트겐슈타인과 튜링의 논쟁을 조명할 수 있으며, 비트겐슈타인의 수학철학의 핵심적인 측면을 살펴볼 수 있다.

• Education of Primary School Mathematics
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• v.13 no.2
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• pp.55-66
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• 2010

The basic direction of mathematical education for the 21st century is focused on helping student to understand mathematics and developing their problem solving abilities, mathematical disposition and mathematical thinking. Elementary mathematics teachers should help students make sense of mathematics, confident of their ability, and make learning environment comfortable for students to participate in. Through making activities 1 to 100 with digits 1,9,9,6, students improved the interest and preference of students about mathematics. This game is useful to foster students' mathematical thinking(concepts of exponential number expression, roots concept(${\sqrt}$), gauss function([])) and mathematical disposition. If students are helped to be interested in mathematics through mathematical games, they regard mathematics as interesting and challengeable subject to let themselves think many ways.

• Communications of Mathematical Education
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• v.26 no.2
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• pp.155-176
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• 2012

In this paper, we present a practical and essential method of using team projects for calculus. We, specifically, take into account the team project that calculate the volume of lung represented on CT scan images. We have demonstrated that the process of analyzing the images in a team project encourage studying numerical methods of integration for calculus. Also, we have used various technological programs(MATLAB, MATHEMATICA, MS Excel) to solve the team project.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.4
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• pp.7-13
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• 2002

In this study, the mathematical model on the various complicated levels of the viscous liquid flows in the symmetric channel with the complicated shape was introduced and the assumptions applied to the simplified model was proposed. To analyse the steady cavitation flow, axis transform of physical region to non-dimensional region was performed, and multigrid were generated. Using this model, the steady cavitation flow was calculated, and good coincidence between experiment and calculation was achieved.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1278-1281
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• 2007

초고속 인터넷망이 발달됨으로써 분산 컴퓨팅 시스템 구축이 용이해졌다. 분산 컴퓨팅 시스템은 저비용과 유휴 계산 자원의 활용으로 기존의 슈퍼컴퓨터와 유사한 능력을 발휘할 수 있다는 장점을 지닌다. 암호 알고리즘의 실질적인 안전성 요소인 키의 길이는 전수조사 계산량에 의존한다. 키 전수조사를 위한 대용량 계산은 슈퍼컴퓨터, 클러스터, 분산 컴퓨팅 등의 환경에 따라 세부적인 메커니즘에 차이를 보인다. 본 논문에서는 분산 컴퓨팅 시스템을 소개하고, 이러한 환경 하에서 암호 알고리즘의 키 전수조사 작업을 수행하기 위한 세부적인 절차에 대해서 논하고, 구체적으로 키 전수조사 작업을 효율적으로 수행하기 위한 방법을 제안한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.353-354
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• 2019

게임에서 캐릭터가 점프 하는 중 플레이어가 스킬을 사용하면, 모든 물체가 정지 되는 기능을 구현해야 하는 상황에 놓이게 된다. Unity Engine에 내장 된 중력을 사용하면, 플레이어가 스킬을 사용 할 때 Rigid Body 속성을 사용하여 움직임을 제한할 수 있다. 그러나, 스킬 사용으로 인한 움직임정지를 해제 할 때 물체의 이전 속력이 사라져 움직임이 부자연스럽게 된다. 이를 해결하기 위해 수학 계산을 통해 시간 값에 따른 중력 값을 대입 하는 방법을 사용하면, 속력이 매우 커 타일을 통과해서 지나가는 현상이 나타난다. 본 논문에서는 다음 프레임 위치 계산을 통해 이러한 문제를 보정하는 방법과 수학 계산식을 통해 속력을 계산했을 때의 문제점 보완 방법 등에 대하여 연구하였다.