• Communications for Statistical Applications and Methods
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• 제13권3호
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• pp.651-656
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• 2006

Wu and Clements-Croome (2005) investigate the optimization problem of PM policies for situations where the quality of PM is a random variable with a certain probability distribution. However, they assume that the cost of preventive maintenance is constant, not depending on the quality of PM. Thus, this paper considers a periodic PM model when PM cost depends on the quality of PM activity. The optimal PM policy are presented for the extended PM model and the numerical examples are presented for illustrative purpose.

• Journal of the Korean Statistical Society
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• 제36권3호
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• pp.367-372
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• 2007

Classification as a tool to extract information from data plays an important role in science and engineering. Among various classification methodologies, support vector machine has recently seen significant developments. The central problem this paper addresses is the accuracy of support vector machine. In particular, we are interested in the situations where fast rates of convergence to the Bayes risk can be achieved by support vector machine. Through learning examples, we illustrate that support vector machine may yield fast rates if the space spanned by an adopted kernel is sufficiently large.

• 대한수학회지
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• 제37권2호
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• pp.297-308
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• 2000

We survey results, obtained in the past three years, on characterizing bounded (and Kobayashi-hyperbolic) Reinhardt domains by their automorphism groups. Specifically, we consider the following two situations: (i) the group is non-compact, and (ii) the dimension of the group is sufficiently large. In addition, we prove two theorems on characterizing general hyperbolic complex manifolds by the dimensions of their automorphism groups.

• 한국지능시스템학회논문지
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• 제3권1호
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• pp.76-89
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• 1993

The evaluation of the Fuzzy Expected Value (FEV) as a typical value requires complete knowledge about the domain of the evaluation, and the distribution of the population in that domain [1]. Since in many situations it is not possible to gather complete knowledge regarding the domain, it is necessary to relax some of the restrictions involving the evaluation of FEV. In this paper we discuss solutions to this problem by using the concept of the Fuzzy Expected Interval (FEI).

• 전자공학회논문지B
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• 제30B권6호
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• pp.1-6
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• 1993

In this paper, we observe that the design of optimal weighted order statistic(WOS) filters minimizing the mean absolute error criterion can be though of as a two-class linear classification problem. Based on this observation, the perceptron algorithm is applied to design WOS filters. It is shown, through experiments, that the perceptron algorithm can find optimal or near optimal WOS filters in practical situations.

• 호남수학학술지
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• 제30권3호
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• pp.411-423
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• 2008

In the field of population dynamics and chemical reaction the possibility or the existence of spatially and temporally nonhomogeneous solutions is a very important problem. For last 50 years or so there have been many results on the pattern formation of chemical reaction systems studying reaction systems with or without diffusions to explain instabilities and nonhomogeneous states arising in biological situations. In this paper we study time-dependent properties of a predator-prey system with functional response and give sufficient conditions that guarantee the existence of stable limit cycles.

• 대한안전경영과학회지
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• 제3권2호
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• pp.123-131
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• 2001

Reliability calculation of a system is frequently required in industrial, military, and everyday life situations. For such a calculation, it is necessary to specify the configuration of components and subsystems, the failure mode of each component, and the states in which the system is classified as failed. In this paper, we are primary interested in the time to the first failure of a system. And we discuss failure probability of coherent system under various condition, especially focus on probability calculation of subsystem failure before system failure used by Bayes formula. Problem statement and general applications illustrated by several examples.

• 한국화재소방학회논문지
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• 제9권2호
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• pp.3-9
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• 1995

Acceptable risk problem are decision problems they requires a choice among different estimations of technological risks. The alternative option includes a threat to life among its consequences. However, the definition used to ignore the public's perceived risk which should be identified as acceptable risk. The study examine the role of perception of risk as acceptable risk between different situations of estimated consequence and probability of risk. The cost benefit principle for the reduction of risk applied to find the possible solutions with in decision making process.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권4호
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• pp.225-237
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• 2016

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer's over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

• 정보교육학회논문지
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• 제9권3호
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• pp.549-560
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• 2005

웹기반 원격연수는 연수자가 교육현장에서 문제해결학습을 통해 주도적으로 문제해결을 수행하도록 구체적이며 실천적인 가능성을 높이는데 중점을 두어야 한다. 수행평가는 교육목표가 실제상황에서 달성되었는지의 여부를 확인하는 것으로 교육문제 해결의 실천적 수행학습을 통해 평가된다. 따라서 본 연구는 초등교원의 원격연수에 대한 인식도 평가결과인 수행평가의 공정성 및 객관성 문제와 원격 연수의 효율적인 평가방법을 반영하고 수행평가결과 처리에 대한 교수자의 과중한 업무 부담을 해소하고 문제수행능력을 신장하는 원격연수 수행평가 방안을 제시하였다. 본 연구 결과 문제중심의 학습 상황 제공, 그리고 개인 및 그룹별 상호작용 생성과 웹 기반 협동평가 및 동료평가를 통한 문제중심 수행평가를 제공하는 모형을 개발하였다.