• East Asian mathematical journal
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• v.17 no.1
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• pp.1-17
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• 2001

In this paper, fuzzy D-continuous function is defined. Some basic properties of this continuity are summarized; and sufficient conditions on domain and/or ranges implying fuzzy D-continuity of fuzzy D-continuous functions are given. Also fuzzy D-regular space is defined and by using fuzzy D-continuity, the condition which is equivalent to fuzzy D-regular space, is given.

• The Pure and Applied Mathematics
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• v.23 no.1
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• pp.21-34
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• 2016

In this paper, we construct a strictly increasing continuous singular function which has a simple algebraic expression.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.4
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• pp.303-307
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• 2010

In this paper, we introduce the concept of fuzzy weakly r-minimal continuous function between a fuzzy r-minimal space and a fuzzy topological space. We investigate characterizations and some properties for the continuity.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.959-968
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• 2005

The piecewise linear histogram can be used as a simple and efficient tool for the density estimator. But, this piecewise linear histogram is discontinuous function. We suppose the piecewise continuous linear histogram as a simple and efficient tool for the density estimator and the alternative of the piecewise linear histogram.

• Communications of the Korean Mathematical Society
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• v.26 no.4
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• pp.709-720
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• 2011

We obtain special type of differential equations which their solution are random variable with known continuous density function. Stochastic differential equations (SDE) of continuous distributions are determined by the Fokker-Planck theorem. We approximate solution of differential equation with numerical methods such as: the Euler-Maruyama and ten stages explicit Runge-Kutta method, and analysis error prediction statistically. Numerical results, show the performance of the Rung-Kutta method with respect to the Euler-Maruyama. The exponential two parameters, exponential, normal, uniform, beta, gamma and Parreto distributions are considered in this paper.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.27-37
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• 2020

Structural optimization problems with discrete design variables require more function calculations (or finite element analyses) than those in the continuous design space. In this study, a method to find an optimal solution in the discrete design of the truss structure is presented, reducing the number of function calculations. Because a continuous optimal solution is the Karush-Kuhn-Tucker point that satisfies the optimality condition, it is assumed that the discrete optimal solution is around the continuous optimum. Then, response values such as weight, displacement, and stress are predicted using approximate models-referred to as hybrid metamodels-within specified design ranges. The discrete design method using the hybrid metamodels is used as a post-process of the continuous optimization process. Standard truss design problems of 10-bar, 25-bar, 15-bar, and 52-bar are solved to show the usefulness of this method. The results are compared with those of existing methods.

• Phonetics and Speech Sciences
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• v.11 no.2
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• pp.23-31
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• 2019

The present study examines whether pitch range variation in North Kyunsang Korean shows a categorical or continuous function. Specifically, the study is focused on the data imitated by adults and children in the North Kyungsang region. To investigate pitch range variation, the log-produced f0 intervals were measured and statistically analyzed. The results of the study are as follows. First, both the adults' and children's imitations were more categorical than continuous, especially for the HL-LH patterns. For the other pitch accent patterns, such as HH-HL and HH-LH, the curves were continuous or flat for most of the speakers. Second, the children's imitations were poorer than those of the adults. That is, the children's imitative responses were shown as more continuous or flat curves than categorical. For the children, the HL-LH pattern showed a categorical function at the midpoint of the curves, though the shifts were not as distinctive as the adults' data. This implies that the imitative responses of children follow the perceptual and productive trace of adults' speech behavior.

• Journal of Educational Research in Mathematics
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• v.23 no.4
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• pp.567-584
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• 2013

In school mathematics, the concept of continuous functions has been intuitively taught. Many researches reported that many students identified the continuity of function with the connectedness of the graphs. Several researchers proposed some ideas which are enhancing the formal aspects of the definition as alternative. We analysed the historical developments of the concept of continuous functions and drew pedagogical implications for the intuitive teaching of continuous functions from the result of analysis.

• Korean Journal of Mathematics
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• v.4 no.2
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• pp.95-100
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• 1996

In this note, the notion of fuzzy almost s-continuity is introduced and some results related to this notion are obtained.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.315-318
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• 2003

This paper proposes a switching control method applicable to any affine, 2nd order nonlinear system with single input. The key contribution is to develop a control design method which uses a piecewise continuous Lyapunov function non-increasing at every discontinuous point. The proposed design method requires no restrictions except full state availability. To obtain a non-increasing, piecewise continuous Lyapunov function, we change the sign of off-diagonal term s of the positive definite matrix composing the former Lyapunov function according to the sign of the Inter-connection term. And we use the solution of inequalities which guarantee each Lyapunov function is non-increasing at any discontinuous point.