• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.409-438
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• 2000

In this paper we develop a new procedure to control stepsize for Runge- Kutta methods applied to both ordinary differential equations and semi-explicit index 1 differential-algebraic equation In contrast to the standard approach, the error control mechanism presented here is based on monitoring and controlling both the local and global errors of Runge- Kutta formulas. As a result, Runge-Kutta methods with the local-global stepsize control solve differential of differential-algebraic equations with any prescribe accuracy (up to round-off errors)

• The Pure and Applied Mathematics
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• v.19 no.4
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• pp.397-407
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• 2012

Let X and Y be vector spaces. We introduce a new type of a cubic functional equation $f$ : $X{\rightarrow}Y$. Furthermore, we assume X is a vector space and (Y, N) is a fuzzy Banach space and then investigate a fuzzy version of the generalized Hyers-Ulam stability in fuzzy Banach space by using fixed point method for the cubic functional equation.

• Steel and Composite Structures
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• v.21 no.5
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• pp.1069-1084
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• 2016

This paper introduces a new and effective design amplification factor-based approach for reliable optimum design of trusses. This paper may be categorized as in the family of decoupled methods that aiming for a reliable optimum design based on a Design Amplification Factor (DAF). To reduce the computational expenses of reliability analysis, an improved version of Response Surface Method (RSM) was used. Having applied this approach to two planar and one spatial truss problems, it exhibited a satisfactory performance.

• Communications for Statistical Applications and Methods
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• v.15 no.5
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• pp.775-781
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• 2008

It is developed that a family of the semicircular Laplace distributions for modeling semicircular data by simple projection method. Mathematically it is simple to simulate observations from a semicircular Laplace distribution. We extend it to the l-axial Laplace distribution by a simple transformation for modeling any arc of arbitrary length. Similarly we develop the l-axial log-Laplace distribution based on the log-Laplace distribution. A bivariate version of l-axial Laplace distribution is also developed.

• KSCI Review
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• v.8 no.2
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• pp.43-50
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• 2001

소프트웨어 신뢰성을 향상시키는 방법에는 소프트웨어 결함 허용기법 중에서 가장 객관적이고 정량적으로 평가받는 것이 NVP(N-Version Programming)기법이다. 이 기법에서 신뢰도를 추정하는 모델로 이항분포를 사용하는데 이 모델은 각 컴포넌트 신뢰도의 값들이 동일하다는 한계점이 있었다. 본 연구에서는 기존 모델의 한계점을 해결하기 위하여 NVP 신뢰도 분석을 위한 새로운 접근 방법으로 유전자 알고리즘(Genetic Algorithms)을 적용하였고. 또한 적용 모델과 기존 모델을 서로 비교 검토하였다. 그 결과 전체시스템 신뢰도를 일정 수준이상 유지하면서 각 컴포넌트 신뢰도의 값들을 최적화 할 수 있었고. 또한 비용을 최소로 하는 최적의 수를 추정할 수 있었다. 그리고 적용 모델과 기존 모델을 비교 및 평가하여 타당성을 증명하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.619-624
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• 1998

This paper presents a new clustering algorithm called FCM algorithm for the design of fuzzy controller. FCM is an extended version of FCM(Fuzzy c-Means) algorithm and can estimate the number of clusters automatically and give membership grades $u_{ik}$ suitable for making fuzzy control rules. This paper also shows an example of its application to the line pursuit control of a car.

• MALSORI
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• no.46
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• pp.127-143
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• 2003

This paper presents segmental labeling conventions proposed by SiTEC (Speech Information Technology Engineering Center) 2002 and proposes a new directions of a revision for a simpler version. The paper also reviews one of the prosody labelling conventions for Korean, K-ToBI convention(ver. 3.1) and proposes a couple of modifications and suggestions.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.511-512
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• 2004

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.193-206
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• 2005

This paper considers a new flow-shop scheduling problem where a different WIP (work-in-process) state has different weight on the duration time. For the two machine case, the recognition version is NP-Complete in the strong sense. Several special cases are solved by different polynomial time algorithms. Finally, we develop a heuristic and provide an upper-bound on relative error which is tight in limit.

• Korean Journal of Logic
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• v.7 no.1
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• pp.1-22
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• 2004

The Kantian idea that some judgments are synthetic even in the area of a priori judgments cannot be accepted in its original version, but a modification of the notions 'analytic' and 'synthetic' discovers a rational core of that idea. The new definition of 'analytic' concerns concepts and makes it possible to distinguish between analytic concepts, which are effective ways of computing recursive functions, and synthetic concepts, which either define non-recursive functions, or define recursive functions in an ineffective way. To justify this claim we have to construe concepts as abstract procedures not reducible to set-theoretical entities.