• Communications of Mathematical Education
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• v.18 no.2 s.19
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• pp.289-294
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• 2004

제 7차 수학과 교육과정에서 벡터는 수학 II에서 다루며, 삼각함수, 좌표와 함께 도형의 성질을 대수적으로 탐구하는 중요한 도구이다. 본 연구에서는 벡터 개념을 이용하여 볼록 n각형의 무게중심의 성질을 탐구하고, 이를 바탕으로 '볼록 n각형에서 n개의 중선은 한 점에서 교차하며 교점은 각 중선을 (n-1):1로 나눈다'는 것을 벡터를 이용하여 증명하였다.

• The Magazine of the IEIE
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• v.11 no.2
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• pp.1-11
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• 1984

본 지 2월호에서 구술한 선형부호에 이어 이번호에서는 순회부호에 대해 기술하고자 한다. 선형블럭부호중 중요한 부류에 속하는 순회부호(cyclic code)는 그 내용이 대수적 구조를 갖고 있어 부호화 회로는 물론 부호에 필요한 오증(syndrome)계산회로 등 귀환연결이 있는 치환레지스터(shift register)를 사용한 장치화(implementation)가 매우 용이하다는 이점이 있다. 이런 순회부호는 산발오진(random error)뿐 아니라 연집오진(burst error)도 정정할 수 있는 매우 효과적인 부호로서 다중오진정정능력(multiple error correcting capability)을 갖는 BCH부호도 순회부호의 일종이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.4 no.2
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• pp.90-118
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• 1994

본 논문에서는 certificatoin-based 방식이 아닌 id-based방식이면서도 사용자가 자신의 비밀키를 선택할 수 있는 역설적인 id-based 방식을 제안한다. 제안한 방식은 Girault가 제안한 self-certified공개키 개념을 id-based방식에 적용한 것이다. 제안한 방식의 안전성은 고차잉여류 문제와 이산대수 문네에 기반을 두고 있다.

• Communications of Mathematical Education
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• v.9
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• pp.97-114
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• 1999

새로운 세기의 수학 교육은 직관과 조작 활동에 바탕을 둔 경험에서 수학적 형식, 관계, 개념, 원리 및 법칙 등을 이해하도록 지도되어야 한다. 즉 학생들의 내면 세계에서 적절한 경험을 통하여 시각적 ${\cdot}$ 직관적으로 수학적 개념을 재구성할 수 있도록 상황과 대상을 제공해야 한다. 이를 위하여 컴퓨터 응용 프로그램을 활용한 자기주도적 수학 개념 형성에 적합한 교수 ${\cdot}$ 학습 모델을 구안하여 보았다. 이는 수학의 필요성과 실용성 인식 및 자기주도적 문제해결력 향상을 위한 상호작용적 매체의 활용이 요구된다. 본 연구는 구성주의적 수학 교수 ${\cdot}$ 학습 이론을 근간으로 대수 ${\cdot}$ 해석 ${\cdot}$ 기하 및 스프레트시트의 상호 연계를 통하여 수학 지식을 재구성할 수 있도록 학습수행지를 제작하여 교사와 학생의 다원적 상호 학습 기회를 제공하는 데 주안점을 두고자 한다.

• School Mathematics
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• v.5 no.1
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• pp.59-76
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• 2003

Algebraic signs are important on learning and problem solving of algebra. This study investigated the contents of letters and expressions in textbooks by syntactics, semantics and pragmatics, and considered the introduction and extension processes of algebraic signs didactically. We also categorized the signs, and looked into textbook problems in view of semiotic. The result is that textbook is constructed in syntactics and semantics. Finally, the assessment of 7th grade students' competence in syntactics, semantics, syntactics+- semantics, pragmatics, and problem solving shows that students' ability in syntactics and pragmatics Is a predictive variable for algebraic problem solving.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.927-930
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• 2005

ACSR is a timed process algebra for the specification and analysis of real-time systems, which supports synchronous timed actions and asynchronous instantaneous events. PACSR is an extended ACSR with the notion of probabilities in selection operation. Using PACSR, this paper represents a system fault occurrence and recovery from the fault in the general resource alteration system. The result shows that system fault occurrence can be analyzed from the fault occurrence probability and the recovery probability.

• Communications of Mathematical Education
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• v.29 no.1
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• pp.91-110
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• 2015

The purpose of this study is to investigate the understanding of pi of elementary gifted students and explore improvement direction of teaching pi. The results of this study are as follows. First, students understood insufficiently the property of approximation, constancy and infinity of pi from the fixation on 'pi = 3.14'. They mixed pi up with the approximation of pi as well. Second, they had a inclination to understand pi as algebraic formula, circumference by diameter. Third, few students understood the property of constancy and infinity of pi deeply. Lastly, the discussion activity provided the chance of finding the idea of the property of approximation of pi. In conclusion, we proposed several methods which improve the teaching of pi at elementary school.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.61-69
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• 2010

In this paper, we present the methodology about an optimal probability distribution selection as well as survival rate estimation with the national highway database from 1999 to 2008. Probability paper methods are adopted to estimate the parameters of each hazard model. The goodness-of-fit test, such as the Anderson-Darling statistics, was performed. As a result, we found that Lognormal distributionan is an appropriate distribution of newly constructed sections as well as overlayed sections. We also ascertained that the results of survival rate for pavement life between the proposed method and observed data are similar. Such a selection methodology and measures based on reliability theory can provide useful information for maintenance plans in pavement management systems as long as additional life data on pavement sections are accumulated.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.7-13
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• 2019

Role-based access or attribute-based access control in cloud environment or big data environment need requires a suitable mathematical structure to represent a hierarchical model. This paper define the notion of multipliers and simple multipliers of lattice implication algebras that can implement a hierarchical model of role-based or attribute-based access control, and prove every multiplier is simple multiplier. Also we research the relationship between multipliers and homomorphisms of a lattice implication algebra L, and prove that the lattice [0, u] is isomorphic to a lattice $[u^{\prime},1]$ for each $u{\in}L$ and that L is isomorphic to $[u,1]{\times}[u^{\prime},1]$ as lattice implication algebras for each $u{\in}L$ satisfying $u{\vee}u^{\prime}=1$.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.107-113
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• 2014

The derivation of optimal information from decision table is based on the concept of indiscernibility relation and approximation space in rough set. Because decision table is more likely to be susceptible to the superposition or inconsistency in decision table, the reduction of attributes is a important concept in knowledge representation. While complete subsets of the attribute's domain is considered in algebraic definition, incomplete subsets of the attribute's domain is considered in information-theoretic definition. Therefore there is a marked difference between algebraic and information-theoretic definition. This paper proposes a conditional entropy using rough set as information theoretical measures in order to deduct the optimal information which may contain condition attributes and decision attribute of information system and shows its effectiveness.