• Journal of Digital Contents Society
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• v.19 no.1
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• pp.199-204
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• 2018

In this paper, we propose a fast collision detection method for interacting with objects in virtual space. First, in the mesh grouping step, the entire space is divided into small spaces of a predetermined size, and the positions and sizes of the smallest basic stereoscopic shapes (cube or sphere) including all of the meshes belonging to each small space are determined. In the collision detection step, it is checked whether a haptic interface point (HIP) is included in a three-dimensional figure representing a group. When a collision with a specific three-dimensional figure is confirmed, searching is performed only for the meshes in the group to find a mesh on which a possible real collision with HIP occurred. The effectiveness of the proposed algorithm is verified by measuring and comparing the computation time of the proposed method with and without the proposed method.

• Journal of Elementary Mathematics Education in Korea
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• v.11 no.2
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• pp.199-216
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• 2007

The purpose of the present study was to analyze the types of errors made by students in the figure domain at the stages of first and second semester of 4th grade in elementary school that include the definition and the properties of figure, to identify the causes of such errors, and to help the teaching of the 4th grade figure domain. When the trends of errors were analyzed for each question, the most common error was the wrong use of theorems or definitions, and its main causes were student's low level in geometry and limited concept images. Thus, it is necessary to make them have clear understanding of these concepts and terms and students need to do various activities suitable for their level in geometry. In addition, figure images presented in the mathematics textbooks and the mathematics practice book have limitations. Thus, figures of various positions and lengths should be presented and described accurately, and the books should be redesigned for various practical activities.

• Journal of Internet Computing and Services
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• v.14 no.4
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• pp.1-12
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• 2013

Context-awareness is a computing technology that automatically delivers useful services to users based on their situation. Most previous studies on context-awareness adopted the view that the user simply is a consumer of what the developer creates. Few studies addressed catering to the need of personalized services for the user. They are either too complex for the user to grasp or unable to express many useful services due to their weak expressive power. To address these issues, we propose Dobby as a new model and architecture for user-driven context-aware service development. Dobby enables the user to create services that are more suited to his personal preferences. We argue that Dobby offers an enhanced method for defining personalized context-aware services over existing methods.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.701-722
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• 2010

Students have to investigate, experiment and inquire using the manipulative materials and real-world thing for studying Geometry. Manipulative materials activities encourage to understand mathematical concept and connection of symbol. Experiment activities using the computer focused the student's intuitive and inquisitive activities because of visualization of an abstract mathematics concept. This study developed a workbook through the use of manipulative materials and computer for operating and experimenting, and suggested a method for inquiry of geometrical properties and proved an effect. Manipulative materials-experiment activities was proven effective to middle level and lower level students in understanding the geometrical properties, and was proven effective to high level and lower level students when it comes to mathematical communication ability. When students operate, at first, they have to know about the feature and information of the materials, and the teacher has to make an elaborate plan and encourages the students to discuss about this.

• Communications of Mathematical Education
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• v.13 no.2
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• pp.693-700
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• 2002

대학수학(미분적분학의 이해, 생활과 수학)수업에서, 공간좌표 단원과 도형편을 지도할 때, 구체적인 모델을 들고 또, 구체적인 예- 쌍곡기하에서는, i)삼각형의 세 내각의 크기의 합은 180도 보다 작다 ii) 피타고라스 정리가 성립하지 않는다. iii) 세 내각의 크기가 90도이고 한 내각의 크기가 90도 보다 작은 사각형이 존재한다. 는 예를 들어 유클리드 기하와 쌍곡기하에 대해 비교 설명하며 수업에 흥미를 불러 일으키고, 새로운 세계에 대한 생각을 할 수 있는 기회를 제공한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.355-364
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• 2018

The objective of this study is to conduct basic research for the development of programs for improving university students' communication competence. As such, it seeks to determine if positive psychological capital can mediate the relationship between the geometric psychology type and communication competence. To that end, 321 Korean university students were surveyed using a questionnaire, and the data underwent scale reliability analysis, regression analysis, and path analysis. Regression analysis revealed the consistent regression results of variables, including geometric psychology type, positive psychological capital, and communication competence. Path analysis confirmed that positive psychological capital mediated the relationship between the geometric psychology type and communication competence, and the results suggested different patterns according to type of geometric psychology. The circle type mediated the sub-variable resilience vis-a-vis communication competence, and directly influenced the latter. The triangle type mediated the sub-factors of positive psychological capital - self-efficacy and resilience -vis-a-vis communication competence, and thus influencing the latter. The square type mediated the sub-factor of positive psychological capital - self-efficacy - vis-a-vis communication competence, and directly influenced the latter. The S type did not mediate positive psychological capital vis-a-vis communication competence, but directly influenced the latter. Thus, considering the above findings, in order to develop university students communication improvement programs, programs should be developed with the application of positive psychological capital considering geometric psychology type.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.47-65
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• 2014

VMS(Variable Message Sign) helps drivers to choose their path to destinations on roadways. Some types of VMS often provide traffic information with clearly visible and comprehensible graphical route diagrams. Currently many diagramed types of VMS are installed on urban arterial and highways. This type of VMS surely enhances drivers' ability to comprehend traffic route information while they are driving on the roadway. Nevertheless, some of them are presented with so much information and design elements and they sometimes lead to decline of drivers' comprehensible level for traffic information. Drivers would fail to decide their preferable route in this state of information overflow. The purpose of this paper is to develop a drivers preference model for effective design principle including size and height of displaying font, and the amount of information in the route diagram considering driving speed, sex and age of the driver. This model is developed using structural equation modeling techniques. This model considers driver's emotional factor and, human factor and design component of route diagram. To collect data, we built driving simulator which is able to replicate real driving condition. 72 people who participated in the simulation were selected considering gender and age. The developed model showed that the amount of information, and visibility are more influential factors to the drivers' preference of the route diagram on VMS than design elements such as the shape and the font of the diagram.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.2
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• pp.361-383
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• 2011

This study is on teaching about the areas of plane figures through open instruction, which aims to discover the pedagogical meanings and implications in the application of open methods to math classes by running the Math A & B classes regarding the areas of parallelogram, triangle, trapezoid and rhombus for fifth graders of elementary school through open instruction method and analyzing the educational process. This study led to the following results. First, it is most important to choose proper open-end questions for classes on open instruction methods. Teachers should focus on the roles of educational assistants and mediators in the communication among students. Second, teachers need to make lists of anticipated responses from students to lead them to discuss and focus on more valuable methods. Third, it is efficient to provide more individual tutoring sessions for the students of low educational level as the classes on open instruction methods are carried on. Fourth, students sometimes figured out more advanced solutions by justifying their solutions with explanations through discussions in the group sessions and regular classes. Fifth, most of students were found out to be much interested in the process of thinking and figuring out solutions through presentations and questions in classes and find it difficult to describe their thoughts.

• Journal for History of Mathematics
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• v.21 no.4
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• pp.169-182
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• 2008

This study has been searching for reasoning process solving the problem effectively in activities related to meaningful classification of pieces and geometric properties with tangram. In activities using some pieces of tangram, we systematically came up with every solution in classifying properties of pieces and combining selected pieces. It is very difficult for regular students to do this tangram. In order to solve this problem effectively, we need to show that there are activities using the idea acquired in reasoning process. Through this process, we do not simply use tangram to understand he concept and play for interest but to use it more meaningfully. And the best solution an not be found by a process of trial and error but must be given by experience to look or it systematically and methods to reason it logically.

• Education of Primary School Mathematics
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• v.21 no.2
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• pp.209-221
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• 2018

Angle concepts have a multifaceted nature such as quantitative aspects as the amount of rotation, qualitative aspects as geometric shapes, and relationship aspects made with planes or lines. This study analysed angle concepts and introduction methods of angles in elementary mathematics textbooks which have been used from the Syllabus Period to the 2015 Revised Mathematics Curriculum. First, the concepts of angles in mathematics textbooks focus through the definitions, representations, and components of angles presented in mathematics textbooks are analyzed. Secondly, how various aspects of each angle are sequenced through the tasks or activties in the introduction of lesson is looked. As a result of analysis, the methods of introducing angles in the changes of mathematics textbooks have mainly focused on learning about geometric shapes and relations of components. In the mathematics classroom, students should experience various aspects of geometric shapes, rotations, relational aspects of points, lines and surfaces, and support and link them to form a wide range of concepts.