• Journal of applied mathematics & informatics
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• 제20권1_2호
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• pp.157-169
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• 2006

We study properties concerning approximation of fuzzy-number-valued functions by fuzzy B-spline series. Error bounds in approximation by fuzzy B-spine series are obtained in terms of the modulus of continuity. Particularly simple error bounds are obtained for fuzzy splines of Schoenberg type. We compare fuzzy B-spline series with existing fuzzy concepts of splines.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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• pp.337-339
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• 1996

In this paper, we construct rough relational database model using approximation concepts of rough set. Also, we analyze the relation between objects, attributes and attribute values and, propose the method that can generate flexible retrieval results.

• 충청수학회지
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• 제24권2호
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• pp.351-357
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• 2011

In this paper, we introduce certain concepts which we will provide us with a perspective and insight into the problem of calculating best approximations. The material of this paper will be mainly, but not only, used in developing algorithms for the one-sided and two-sided sided approximation problem.

• 충청수학회지
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• 제24권4호
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• pp.849-862
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• 2011

In this paper, we introduce certain concepts which provide us with a perspective and insight into the generalization of orthogonality with the normalized duality mapping. The material of this paper will be mainly, but not only, used in developing algorithms for the best approximation problem in a Banach space.

• Steel and Composite Structures
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• 제8권5호
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• pp.343-359
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• 2008

In the present study, an efficient method for the optimum design of three-dimensional (3D) steel framed structures is proposed. In this method, in addition to choosing the best position of columns based on architectural requirements, the optimum cross-sectional dimensions of elements are determined. The preliminary design variables are considered as the number of columns in structural plan, which are determined by a direct optimization method suitable for discrete variables, without requiring the evaluation of derivatives. After forming the geometry of structure, the main variables of the cross-sectional dimensions are evaluated, which satisfy the design constraints and also achieve the least-weight of the structure. To reduce the number of finite element analyses and the overall computational time, a new third order approximate function is introduced which employs only the diagonal elements of the higher order derivatives matrices. This function produces a high quality approximation and also, a robust optimization process. The main feature of the proposed techniques that the higher order derivatives are established by the first order exact derivatives. Several examples are solved and efficiency of the new approximation method and also, the proposed method for the best position of columns in 3D steel framed structures is discussed.

• 한국지능시스템학회논문지
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• 제11권5호
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• pp.441-447
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• 2001

In general, Rough Set theory is used for classification, inference, and decision analysis of incomplete data by using approximation space concepts in information system. Information system can include quantitative attribute values which have interval characteristics, or incomplete data such as multiple or unknown(missing) data. These incomplete data cause tole inconsistency in information system and decrease the classification ability in system using Rough Sets. In this paper, we present various types of incomplete data which may occur in information system and propose INcomplete information Processing System(INiPS) which converts incomplete information system into complete information system in using Rough Sets.

• 대한수학회보
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• 제57권3호
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• pp.781-802
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• 2020

For a fixed semi-Wakamatsu-tilting module _AT, we generalize the concepts of Auslander class, Bass class, and investigate many homological properties of such classes. Moreover, we establish an equivalence between the class of ∞-T-cotorsionfree modules and a subclass of the class of T-adstatic modules. Finally, a similar version of Auslander-Bridger approximation theorem and a nice property of relative cotranspose are obtained.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제23권3호
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• pp.625-642
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• 2009

우리나라 학교수학에서는 접선에 대한 개념을 학년별로 다양하게 제시하고 있다. 학년이 올라감에 따라 이전 학년에서 학습했던 개념을 점차 수정하면서 최종적으로는 할선의 극한으로서의 접선의 개념에 도달한다. 이 연구에서는 선형 사로서의 접선 개념을 도입하고 이에 대한 수학 교육학적 의미에 대하여 고찰한다. 이 개념이 비선형 문제의 국소적 측면을 다룰 때 이를 선형화 시켜서 바라보는 현대 수학의 중요한 관점을 내포하고 있음을 살펴본다. 이 개념의 교수학적 변환으로서 접선을 이용하여 제곱근의 값을 근사적으로 구하는 방법을 알아보고, 이를 통하여 접선 개념의 학습에 대한 긍정적인 태도, 흥미, 동기 부여 등의 정의적인 요소들을 증진시킬 수 있음을 논의한다. 또한, 이 개념을 통하여 첨점이 있는 그래프에서 첨점의 좌우에서 서로 다른 접선이 생길 경우 학생들이 가질 수 있는 오류의 의미 분석 및 그 해소 방안을 모색한다.

• 한국추진공학회지
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• 제24권3호
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• pp.18-30
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• 2020

본 연구는 고체추진기관의 추력측정불확도 추정 방법에 관한 것이다. 힘 측정불확도 추정 지침은 ISO와 국내외 기구에서 제공하고 있으나 모든 내용이 실험실에서 운용하는 하중시험기와 하중 센서의 교정을 중심으로 기술되고, 개념적으로 기술되어 있다. 추력시험대 불확도의 주요 원인인 교정식과 선형화 불확도의 추정에 대해서는 해당 지침을 직접 적용할 수는 없다. 본 논문에서는 측정불확도 기본 개념을 이용하여 교정식 불확도와 교정식의 선형화 불확도를 추정하는 식을 만들고, 이를 추력 시험대의 추력측정불확도에 추정하여 적용하였으며, 비교적 간단한 추력측정불확도 추정 방법을 제안하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.243-251
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• 2000

In general, Rough Set theory is used for classification, inference, and decision analysis of incomplete data by using approximation space concepts in information system. Information system can include quantitative attribute values which have interval characteristics, or incomplete data such as multiple or unknown(missing) data. These incomplete data cause the inconsistency in information system and decrease the classification ability in system using Rough Sets. In this paper, we present various types of incomplete data which may occur in information system and propose INcomplete information Processing System(INiPS) which converts incomplete information system into complete information system in using Rough Sets.