• Computational Structural Engineering
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• v.10 no.2
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• pp.243-254
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• 1997

When dynamic loads such as mechanical load, wind load, and seismic load, which causing a vibration, acts on the body of the 3-D framework resting on soil foundation, it is required to consider the dynamic behavior of soil-space framework interation system. Thus, this study presents the 3-dimensional soil-interaction system analyzed by finite element method using 4-node plate elements with flexibility, 2-node beam elements, and 8-node brick elements for the purpose of idealizing an actual structure into a geometric shape. The objective of this study is the formulation of the equation for a dynamic motion and the development of the finite element program which can analyze the dynamic behavior of soil-space framework interaction system.

• The Mathematical Education
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• v.53 no.4
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• pp.493-507
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• 2014

The purpose of this study is to analyze how high school students form and interpret the mental image in the process of solving regular polyhedron problems. For this purpose, a set of problems about the regular polyhedron's vertex is developed on the base of the regular polyhedron's duality and circulation. and applied to 2 students of the 12th graders in D high school. After 2 hours of teaching and learning and another 2 hours of mental image-analysis process, the following research findings are obtained. Fisrt, a student who recorded medium high-level grade in the national scholastic test can build the dynamic image or the patten image in the process of solving regular polyhedron's vertex problems by utilizing the 3D geometry program. However, the other student who recorded low-level grade can build the concrete-pictorial image. Second, pattern image or dynamic image can help students solve the regular polyhedron's vertex problems by proper transformation of informations and the mental images while the concrete-pictorial image does not help. Hence, it is recommended that the mathematics teachers should develop teaching and learning materials about the regular polyhedron's duality and circulation and also give students suitable questions to build the various mental images.

• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.345-366
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• 2006

In this study, we investigated the methods of using the Cabri3D program for education of problem solving in school mathematics. Cabri3D is the program that can represent 3-dimensional figures and explore these in dynamic method. By using this program, we can see mathematical relations in space or mathematical properties in 3-dimensional figures vidually. We conducted classroom activity exploring Cabri3D with 15 pre-service leachers in 2006. In this process, we collected practical examples that can assist four stages of problem solving. Through the analysis of these examples, we concluded that Cabri3D is useful instrument to enhance problem solving ability and suggested it's educational usage as follows. In the stage of understanding the problem, it can be used to serve visual understanding and intuitive belief on the meaning of the problem, mathematical relations or properties in 3-dimensional figures. In the stage of devising a plan, it can be used to extend students's 2-dimensional thinking to 3-dimensional thinking by analogy. In the stage of carrying out the plan, it can be used to help the process to lead deductive thinking. In the stage of looking back at the work, it can be used to assist the process applying present work's result or method to another problem, checking the work, new problem posing.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.513-516
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• 2006

인터넷의 발달로 인터넷 사용자는 기하급수적으로 증가하게 되었으며, 인터넷을 기반으로 하는 수많은 응용프로그램들이 개발되고 있다. 인터넷상에는 수많은 사이트(site)들이 존재하며 방문자들의 주목을 받기 위하여 여러 가지 기법을 선보이고 있다. 그러나 컴퓨터상의 정적인 2차원 평면하에서는 현실감 및 입체감을 경험하는 것이 한계가 있다. 따라서 플래시(flash)와 같은 플러그인(plug-in) 및 동영상을 도입하여 동적인 컨텐츠를 제공하는 사례가 늘고 있으며 한편으로 최근 가상현실(Virtual Reality) 기법을 이용한 사이트들이 점차 증가하고 있는 추세이다. 가상현실은 컴퓨터가 제공하는 3차원의 컴퓨터 그래픽 기술을 이용하여 사용자와 온라인으로 상호대화를 하는 기법이라고 간단히 정의할 수 있다[2,3]. 가상현실을 이용하여 3차원 실시간 구현 기술을 웹에 적용시킴으로서 3차원 공간에서 현실감을 느낄 수 있게 함과 동시에 입체적인 정보를 사용자에게 제공할 수 있게 하는 기법들이 속속 선보이게 되었다. 현재 다양한 인터넷 기반 3차원 가상 현실 기술이 각각 서로 다른 기술 및 특징들을 가지고 나와 있다. 3차원 가상 공간을 구현한다. 선택한 물체에 사진 이미지기반 방식과 3차원 모델링 방식을 모두 적용하여 보다 현실감 있고 모든 방향으로의 접근이 가능하도록 하며. 또한 3차원 사운드 및 동영상도 함께 제공하며 가상 공간과 인간의 실질적 교감을 현실화 시키는 인터페이스를 제시하는 데에 연구의 목적이 있다.