• Review of KIISC
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• v.8 no.4
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• pp.5-14
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• 1998

본 논문에서는 공개키 암호 방식에 대한 안전성 개념들을 종합적으로 조사하고 분석한다. 의미론적 안전성(semantic security ), 구별불능 안전성(indistinguishable encryption), NM- 안전성(non-malleability)등에 대한 개념을 소개한다. 그리고 이들 개념에 공격(attack)관점의 안전성을 결합한 정의에 대해서 고찰하며, 소개한 개념들 사이의 수학적 관계를 규명한다.

• Product Safety
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• s.53
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• pp.14-17
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• 1997

소비자라는 용어는 공급자 중심 체제하에서 공급자인 기업이 상품소비대상을 지칭하는 개념이였다. 물자부족, 인력과잉현상이 지속되던 시대에서는 공급자를 제외한 모든 구매자는 물자는 소비하는 층이었다. 그러나 이제 그 소비자 개개인의 독특한 개성을 기준으로 상품을 선택하는 시대가 된 것이다. 따라서 기업경영자로서의 우리는 이제부터 구매자를 소비자라는 개념에서 고객이라는 개념으로 바꾸어 부르도록 하자.

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.545-557
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• 2004

The purpose of this study is to classify types of preconception on the seasonal change to middle school students and to find out how the developed multimedia material changes their conception in the seasonal change. The questionnaire about the variation of season consisted of 10 items. Questions are given to 80 ninth graders. Control and experimental group was 23 and 57 students, respectively and they were instructed for two class periods. A learning method using multimedia was applied to the experimental group. On the other hand, traditional teaching-learning method was used for the control group. A learning method using multimedia in this study had an effect on the conceptual changes (p$<$0.01). Data in this study was divided into six levels to classify the changes of concepts in detail. As a result, it showed that a learning method using multimedia was effective for students to make progress from unscientific to scientific concepts, to build up scientific concepts, to build up scientific concepts, and to elaborate scientific concepts as compared with traditional method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.453-460
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• 2013

This study proposes a framework that enables efficient integration and usage of enterprise data using semantic based concept net. Integration of enterprise information that has been increasing geometrically in cloud environment. The concept net is very similar in approaching way to existing ontology. However, it builds correlation between object and concept to help user's information integration retrieval more efficiently. In this study, concept nets are divided into 3 kinds and are applied to the proposed framework independently. The concept net in this study is built in ontology format based on master information concept net, keyword concept net and business process concept net. This concept net enables retrieval and usage of data based on correlation among data according to user's request. Then, through combination of master information concept and keyword concept, it provides frequency trace of keyword and category thus improving convenience and speed of retrieval.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.269-282
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• 2007

We propose a personalized concept-based retrieval technique that uses domain ontology. Proposed system consist or representative concept extraction, user profile construction, and concept-based retrieval stages. First, we extract representative concept with using technique form contents and create the domain ontology. We compose user profile analysis that uses domain ontology for personalized concept-based retrieval. To verify the efficiency of the proposed technique, we perform experiment for Internet site in the engineering area. The results of experiment show that the proposed technique using the domain ontology and user profiles is more efficient than the existing techniques. Hence, the proposed concept-based retrieval technique can be expected to contribute to the development of an efficient personalized recommendation system or e-Commerce system.

• Information Systems Review
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• v.13 no.1
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• pp.97-114
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• 2011

Two conceptually thorny issues in IT governance definition and understanding are examined and discussed. It is argued that the traditional IT governance definition, which defines governance in terms of the content of enterprise IT activity, is prone to logical inconsistency and indeterminacy. A new objectives-bound definition of IT governance is proposed as a remedy to the problem. It is proposed that the essence of the objectives-bound IT governance lies in making enterprise IT activity explicit, formal and subject to external scrutiny in its effort to achieve the effectiveness, transparency and accountability of IT. A conceptual apparatus called IT activity axes is employed to characterize and distinguish the different approaches to IT governance definition and understanding. It is suggested that IT governance can be defined using a simple frame of reference with logical consistency and coherence. The theoretical and practical implications of the IT governance definition are discussed at the end.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.393-400
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• 2006

This study is intended to examine the characteristics of driver in the use of guide sign in urban areas. The good and bad points about guide sign based on landmark point and guide sign based on street name are demonstrated, and driver's preference between them are studied. The questionnaires given to general persons deal with general guide signs and road maps, and are designed to see if they can find out current location on the road map with guide sign. According to the results, drivers prefer guide sign based on street name to guide sign based on landmark. And guide sign based on street name took less time to find current location than with guide sign based on landmark.

• Journal of the Korean earth science society
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• v.24 no.7
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• pp.595-603
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• 2003

The study investigated the effect of a social constructivist model on changes of concept on 103 4th graders in three elementary schools. In particular, it analyzed whether the application of a concept circle map developed student understanding of the concept. After a one month study period, the 103 students took a pencil and paper test on changes of concepts learned. The results indicated that the social constructivist model positively influenced student concept development. In conclusion, a concept circle map used on a social constructivist model may be employed as a tool for diagnostic or formative evaluation.

• Journal of the Korean School Mathematics Society
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• v.6 no.1
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• pp.163-175
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• 2003

The research was aimed to find a special quality to the mathematical concept development using a graphing calculator in the collaborative learning. I could observe the process in which the students had formed the generalized and abstract mathematical concepts after they were given different concepts. I \ulcorner-Iso observed the characteristics of how they started with a vague syncretic conglomeration and approached to the complicated thoughts and genuine concepts. The advance of the collection type was achieved in the process of teacher's confirming of what the students had observed with a calculator. The language and the instrument were used in order for students to control the partial process. Also, they were given similar types of problems to make them clear when the students confronted 'the crisis of thoughts' at the level of pseudo-concept.

• School Mathematics
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• v.17 no.4
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• pp.571-591
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• 2015

Even though fractions make up one of the most important concepts in the domain of numbers in elementary math, it is difficult to teach or learn them due to their different quantity concepts and notation methods from natural numbers and their various concepts. The didactic transposition of fractions is thus important, and there is a need to examine the didactic concepts of fractions used in the South Korean textbooks for its research. This study compared elementary math textbooks among South Korea, Taiwan, and China and investigated differences in the instructional time and order of fraction concepts in the textbooks according to their didactic concepts and also differences in the instructional methods according to quantitative concepts.