• Journal of applied mathematics & informatics
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• 제12권1_2호
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• pp.251-260
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• 2003

Generally, in deriving the solution of economic production quantity (EPQ) inventory model, we consider the demand rate and deterioration rate as constant quantity. But in case of real life problems, the demand rate and deterioration rate are not actually constant but slightly disturbed from their original crisp value. The motivation of this paper is to consider a more realistic EPQ inventory model with finite production rate, fuzzy demand rate and fuzzy deterioration rate. The effect of the loss in production quantity due to faulty/old machine have also been taken into consideration. The methodology to obtain the optimum value of the fuzzy total cost is derived and a numerical example is used to illustrate the computation procedure. A sensitivity analysis is also carried out to get the sensitiveness of the tolarance of different input parameters.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권2호
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• pp.90-96
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• 2005

This paper presents hardware scheme of fuzzy inference engine, based on α-level set decomposition of fuzzy sets for fuzzy control of DC servo system. We propose a method which is directly converted to PWM actuating signal by a one body of fuzzy inference and defuzzification. The influence of quantity α-levels on input/output characteristics of fuzzy controller and output response of DC servo system is investigated. It is concluded that quantity α-cut 4 give a sufficient result for fuzzy control performance of DC servo system. The experimental results shows that the proposed hardware method is effective for practical applications of DC servo system.

• 산업경영시스템학회지
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• 제17권32호
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• pp.7-16
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• 1994

In the existing deterministic network, the capacity of each arc has determined property. But actually, it may be a property which cannot be determined. Even though it should be determining, it contains many errors. In treating these kinds of problems, fuzzy theory is suitable. Recently, due to development the study on complicated and indefinited systems which contain fuzziness could be possible. This paper includes that the capacity of each arc and the goal quantity with nonnegative integer have the fuzziness. The object is to search the new mathod of fuzzy maximal flow quantity. If the degree of arc membership function of the minimal cut part is not larger than that of arc membership function of the part except the minimal cut, first calcurate nonfuzzy maximal flow quantity, and then can compute the optimal quantity the 3rd step at one time with Max-Min fuzzy operating in the arc capacity of minimal cut and the goal quantity without a great number of recalculation.

• Journal of applied mathematics & informatics
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• 제42권2호
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• pp.379-390
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• 2024

This study proposes a fuzzy inventory model for managing large-scale production, incorporating cost considerations. The model accounts for two types of expenditure scenarios-parametric and exponential. Uncertainty surrounds holding costs, setup costs, and demand rates. The approach considers a supply chain system with a complex manufacturing process, factoring in transportation costs based on the quantity of goods and distance between the supplier and retailer. The initial crisp model is then transformed into a fuzzy simulation, incorporating specific fuzzy variables affecting inventory costs. The proposed method significantly reduces overall inventory costs for the entire supply chain. Retailer demand is linked to inventory levels, and vendor/distributor storage deteriorates over time. The fuzzy condition assumes hexagonal variables for all associated factors. The study employs the signed distance method for defuzzification to determine the optimal order quantity with hexagonal fuzzy numbers. Mathematical examples are provided to illustrate the practicality of the proposed approach.

• 한국국방경영분석학회지
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• 제18권2호
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• pp.56-65
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• 1992

In the existing deterministic network, the capacity of each arc has been assumed to have a determined property. In reality it may have a property which cannot be determined, and even if it is determined, it contains many errors. Fuzzy theory is efficient in dealing with these kinds of properties. The object of this study is to show that the capacity of each arc and the goal quantity have fuzziness and to develop a new method of determining the fuzzy maximal flow quantity.

• 한국지능시스템학회논문지
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• 제12권3호
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• pp.193-201
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• 2002

교통의 혼잡량이라든가 공기의 쾌적도등을 측정할 때는 상징적인 정보량을 이용한 퍼지 센서 알고리즘을 사용한다. 그런데 퍼지센서를 구현할 경우 몇 개의 상징적인 정보량을 퍼지 규칙으로서 종합하여 출력을 산출하는데 상징적인 정보량을 퍼지 규칙이라는 막연한 방법을 사용하므로서 정확하지 못한 결과를 산출 할 수 밖에 없다. 따라서 본 논문에서는 퍼지 규칙으로 퍼지센서를 구현하는 방법이 아닌 계층분석 방법이라는 분석적인 방법을 이용하여 퍼지센서를 구현하였고 이를 검증하기 위하여 퍼지 규칙방법의 퍼지센서와 계층분석방법의 퍼지센서를 교통량 제어에 적용하여 많은 통과차량수의 검증을 통하여 비교하여 보았다

• Journal of applied mathematics & informatics
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• 제9권1호
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• pp.433-440
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• 2002

In this paper, we first prove the existence of fixed points for fuzzy mappings that satisfy a certain contractive condition. Also, we give a fixed point theorem for generalized contractive fuzzy mapping by using Caristi's by fixed point theorem.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2005년도 추계학술대회 학술발표 논문집 제15권 제2호
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• pp.448-451
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• 2005

교통의 혼잡량이라든가 공기의 쾌적도 둥을 측정할 때는 상징적인 정보량을 이용한 퍼지 센서 알고리즘을 사용한다. 그런데 퍼지 센서를 구현할 때는 몇 개의 상징적인 정보량을 퍼지 규칙으로서 종합하여 출력을 산출하는데 상징적인 정보량을 퍼지 규칙이라는 막연한 방법을 사용하므로서 정확하지 못한 결과를 산출할 수밖에 없다. 따라서 본 논문에서는 퍼지 규칙으로 퍼지 센서를 구현하는 방법이 아닌 계층 분석 방법이라는 분석적인 방법을 이용하여 퍼지 센서를 구현하였고 이를 검증하기 위하여 퍼지 규칙 방법의 괴지 센서와 계층 분석 방법의 퍼지 센서를 교통량 제어에 적용하여 많은 통과차량수의 검증을 통하여 비교하여 보았다.

• Journal of the Korean Data and Information Science Society
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• 제14권1호
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• pp.93-101
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• 2003

Computation with fuzzy numbers is a prospective branch of a fuzzy set theory regarding the data processing applications. In this paper we consider an open problem about distributivity of fuzzy quantities based on the extension principle suggested by Mare (1997). Indeed, we show that the distributivity on the class of fuzzy numbers holds and min-norm is the only continuous t-norm which holds the distributivity under t-norm based fuzzy arithmetic operations.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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• pp.22-24
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• 2002

Computation with fuzzy numbers is a prospective branch of a fuzzy set theory regarding the data processing applications. In this paper we consider an open problem about distributivity of fuzzy Quantities based on the extension principle suggested by Mares (1997). Indeed, we show that the distributivity on the class of fuzzy numbers holds and min-norm is the only continuous f-norm which holds the distributivity under f-norm based fuzzy arithmetic operations.