• Journal of Elementary Mathematics Education in Korea
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• v.18 no.2
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• pp.237-255
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• 2014

The purpose of this study is to investigate elementary school students' understanding the concept and operations of decimal fraction. The survey research was performed for this study. This survey was done by selecting 156 students. Questionnaire were made in five areas with reference to the 2007 revised mathematics curriculum. Five areas were the concept of decimal fraction, the addition, the subtraction, the multiplication and the division of decimal fraction. The results of such analysis are as follow: The analyzed result of understanding about concepts and operation of decimal fraction showed a high rate of correct answer, more than 85%. Students thought that multiplication and division of decimal fraction is more difficult than addition, subtraction, concept of decimal fraction. As the learning about concepts and operation of decimal fraction progress, the learning gap is bigger. Effort to reduce the learning deficits are needed in the lower grades. Mathematics is the study of the hierarchical. Learning deficits in low-level interfere with the learning in next-level. Therefore systematic supplementary guidance for a natural number and decimal fraction in low-level is needed. And understanding concepts and principles of calculations should be taught first.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.1
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• pp.37-62
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• 2014

In this thesis, we inquire into teaching method of decimal fraction concept in elementary mathematics education based on measurement activity. For this purpose, our research tasks are as follows: First, we design a experimental learning-teaching plan of 'decimal fraction' unit in 4th grade textbook and verify its effect. Second, after teaching experiment using experimental learning-teaching plan, we analyze the student's status of understanding about decimal fraction concept. As stated above, we have performed teaching experiment which is ruled by new lesson design and analysed the effects of teaching experiment. Through this study, we obtained the following results. First, introduction of decimal fraction based on measurement activity promotes student's understanding of measuring number and decimal notation. Second, operator concept of decimal fraction is widely used in daily life. Its usage is suitable for elementary mathematics education within the decimal notation system. Third, a teaching method of times concepts using place value expansion of decimal fraction is more meaningful and has less possibility of misunderstanding than mechanical shift of decimal point. Fourth, teaching decimal fraction through the decimal expansion helps students with understanding of digit 0 contained in decimal fraction, comparing of size and place value. Fifth, students have difficulties in understanding conversion process of decimal fraction into decimal notation system using measurement activity. It can be done easily when fraction is used. However, that is breach to curriculum. It is necessary to succeed research for this.

• Journal of Educational Research in Mathematics
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• v.15 no.3
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• pp.287-313
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• 2005

The decimal fraction concept plays an important role in understanding the real number which is one of the major concepts in school mathematics. In the school mathematics of Korea, the decimal fraction is treated merely as a sort of name of the common fraction, while many other important aspects of the decimal fraction concept are ignored. In consequence students fail to understand the decimal fraction concept properly, and merely consider it as a kind of number for formal computation. Preceding studies also identified students' narrow understanding of the decimal fraction concept. But none of them succeeded in clarifying the essences of the decimal fraction concept, which are crucial for discussing the didactical problems of it. In this study we attempted a didactical analysis of the decimal fraction concept and disclosed the roots of didactical problems and presented measures for its improvement. First, we attempted a phenomenological analysis of the decimal fraction concept and extracted 9 elements of the decimal fraction concept. Second, we has analyzed of the essence of the decimal fraction concept more clearly by relating it to the situations where it functions and its representations. For this we tried to construct the conceptual field of the decimal fraction. Third, we categorized he developmental levels of the decimal fraction concept from the aspect of external manifestation of the internal order. On the basis of these results, we attempted hierarchical structuring of the elements of the decimal fraction concept. And using the results of such a didactical analysis on the decimal number concept we analyzed the mathematics curriculum and textbooks of our country, investigated levels of students' understanding of the decimal fraction concept, and disclosed related problems. Finally we suggested directions and measures for the improvement of teaching decimal fraction concept.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.351-352
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• 2013

다양성은 문화산업의 기반을 풍부하게 해주는 중요한 요소이다. 다양성영화는 비주류, 다문화, 소수, 마니아 적인 성격을 가지고있는 예술영화, 다큐멘터리, 독립영화를 포괄하는 개념이다. 이러한 개념을 바탕으로 하는 다양성영화는 지역의 다양한 소재를 활용하고 다양한 의견을 포괄할 수 있어서 문화적인 풍부함을 이룰 수 있게 하는 근간이 된다. 이 글에서는 다양성영화가 문화산업의 기반 구조를 충실히 하는 중요한 매개가 될 수 있음을 보이고 이를 고찰하였다.

• School Mathematics
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• v.16 no.3
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• pp.613-631
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• 2014

The aim of this study was to investigate how the small group activity system influences individual to form concepts of prime number and composite number through activity theory on learning process of mathematically gifted 5th-grade students. Student's worksheets, recorded video, and interview were gathered and transcribed for analyzing data. Process of concept formation and using symbol behavior were used to derive the stage of mathematical concept from students, and the activity system and stage of concept formation process were schematized through analysis of whole class activity system and small group activity system based on activity theory. According to the results of this study, two students who were in different activity groups separated into the state of semi-concept and the stage of complex thinking respectively, and therefore, social context and the activity system had effects on process of concept formation among the students.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1113-1116
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• 2000

기존의 연구에서는 셀룰러 망에서 호 수락 제어 시에 다음 두 가지 요소를 고려하지 않는다. 첫 번째 요소는 각각의 셀, 특히 micro/pio 셀에서 서비스 제공이다. micro/pico 셀과 같이 심한 트래픽 변동이 있는 셀에서는 호 단절률이 수렴할 수 없기 때문에 이동 QoS와 서비스 제공이 불가능하다. 두 번째 요소는 망에서 호를 수용할 수 있는 능력과 관련 있는 GOS 이다. 일반적으로 여러 비율의 서비스는 서비스의 집합으로 특정지을 수 있고, 각각의 것들은 다른 양의 대여폭을 요구한다. 이질적인 멀티미디어 서비스 클래스를 가진 망에서는 소수의 광대역호가 망 자원의 대부분을 점유해서, 신규호에 대한 봉쇄로 망 성능을 떨어뜨릴 수 있다 그래서, GoS는 광대역호 제어에 의해서 향상될 수 있다. 본 논문에서는 이동 트래픽 조건에서 서비스 제공이 가능한 셀들의 최소 집합이면서 논리적인 단위인 지역이라고 불리는 새로운 개념을 소개한다. 그리고 서비스 제공 단위가 셀보다는 지역단위로 한 경우에 성능이 더 좋고 GoS 를 향상시킬 수 있는 방법인 지역기반 CAC 를 제한한다. 마지막으로 시뮬레이션에서는 QoS와 GoS 관점에서 RCAC가 현재까지 제안된 다른 방법보다 더 좋은 성능을 제공한다는 것을 보여준다.

• International Commerce and Information Review
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• v.15 no.3
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• pp.431-451
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• 2013

The aim of this study is to thoroughly review prior literature related to electronic bill of lading and investigate the current state of electronification of operational processes of both major international and domestic shipping lines. In addition, this study examines the meaning of Electronic Bill of Lading; the perception on Electronic Bill of Lading; and the impediment to Electronic Bill of Lading in the perspective of shipping lines. As a result, following obstacles deter further development of e-B/L: negative attitude on the utilization of e-B/L; the matter of trust on the utilization of e-B/L; and technical issues in relation to the use of e-B/L.

• Journal of The Korean Association For Science Education
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• v.25 no.5
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• pp.583-594
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• 2005

This study examined 8th-graders' conceptions of force on a simple pendulum and investigated cognitive conflict and conceptual change through kinesthetic experience in swing. Participants of this study were guided to anticipate the direction of total force acting on a pendulum at three critical positions and observed it through swing experience. Having completed this, students read an article explaining the results they observed. Most of them considered gravity, tension, and motion-force to be the real forces acting on a pendulum in pre-test. Though they were interested in the activity and conceded their expectations to be different from observed results, the degrees of their cognitive conflict were not significantly high. In summation, 'interest' was the highest and 'anxiety' was the lowest. Most of the students memorized the direction of forces on a swing, but few could explain the reason behind the occurrence in an immediate post-test and delayed post-test.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.665-673
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• 2014

The Korean film market has revved up against American movies and the movie industry has continued to grow even though Korea is a small country. However, most production staffs who are responsible for practical business of film production get wages that fall short of the inflation rate and minimum wages as temporary employees. And there's the atmosphere that they try to leave film sites on the first opportunity. This study finds that the cause to leave film sites is attributed to perception gaps about the hardworking character and labor which occur in the process that production staffs enter the movie industry and participate in film production as well as poor surroundings. And it should establish staffs' hardworking character and recognition as workers to them by reorganizing the current curriculums which approach movies from the only artistic viewpoint in the departments related to movies and images that hold a large majority in their majors, establishing the concept of work according to participation in film production to potential production staffs, and changing their recognition to improve the elements that they leave the sites.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.976-983
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• 2009

Ambient Information System is an expanded term from Ambient Displays that are aesthetically pleasing displays of information which sit on the periphery of a user's attention. It describes a large set of applications that publish information in a highly non-intrusive manner[4]. Recently, as importance of the media that affects human senses and individuals' experiences increases, the role of an Ambient Information System for Public is also increase. Therefore, in this paper, the emphasis is on finding a suitable form of the Ambient Information System based on some design dimensions and we sampled possible 13 design dimensions of the practical application of an Ambient Information System for Public. For verifying the validity of our findings, we installed "Follwingflow", an interactive LED illumination and carry out an experiment on the dimensions.