• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1342-1345
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• 1993

In the cellular mobile communications as decreasing the cell radius to increse the reuse factor of frequencies, the handoff requests are increasing so that the efficient handoff decision making becomes a crucial problem. In this simulation study, we evaluate a set of handoff algorithms based on fuzzy-multicriteria decision making. These algorithms uses the parameters including the received signal strength intensity, the bit error rate and the distance between a mobile station and a base station. We compare the fuzzy algorithms in terms of call block ratio and handoff request ratio and call force ratio, and show the applicability of those algorithms in the cellular mobile communication systems.

• 산업경영시스템학회지
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• 제20권41호
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• pp.41-50
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• 1997

In this paper, we presents the method for finding the compensatory solution for fuzzy multiobjective nonlinear programming problem with fuzzy parameters involved in the problem-formulation process and fuzzy equal goals of the decision maker for each of the objective functions. The fuzzy parameters in the objective functions and the constraints characterized by fuzzy numbers. The proposed method can be applied to case with multiobjective problems and guarantee an efficient solution. An illustrative numerical example is presented.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 추계 학술발표회 논문집
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• pp.3-8
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• 1998

The present work proposes the potential fuzzy framework, based on fuzzy set theory, for supporting decision-making problems, especially, selection problems of a best design in the area of nuclear energy system. The framework proposed is composed of the hierarchical structure module, the assignment module, the fuzzification module, and the defuzzification module. In the structure module, the relationship among decision objectives, decision criteria, decision sub-criteria, and decision alternatives is hierarchically structured. In the assignment module, linguistic or rank scoring approach can be used to assign subjective and/or vague values to the decision analyst's judgment on decision variables. In the fuzzification module, fuzzy numbers are assigned to these values of decision variables. Using fuzzy arithmetic operations, for each alternative, fuzzy preference index as a fuzzy synthesis measure is obtained. In the defuzzification module, using one of methods ranking fuzzy numbers, these indices are defuzzified to overall utility values as a cardinality measure determining final scores. According these values, alternatives of interest are ranked and an optimal alternative is chosen. To illustrate the applicability of the framework proposed to selection problem, as a case example, the best option choice of four design options under five decision criteria for primary containment wall thickening around large penetrations in an advanced nuclear energy system is studied.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2222-2229
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• 2023

Radon and radon progeny being natural radioactive pollutants, seriously affect the health of uranium miners. Radon reduction by ventilation is an essential means to improve the working environment. Firstly, the relational model is built between the radon exhalation rate of the loose body and the ventilation parameters in the stope with radon percolation-diffusion migration dynamics. Secondly, the model parameters of radon exhalation dynamics are uncertain and described by triangular membership functions. The objective functions of the left and right equations of the radon exhalation model are constructed according to different possibility levels, and their extreme value intervals are obtained by the immune particle swarm optimization algorithm (IPSO). The fuzzy target and fuzzy constraint models of radon exhalation are constructed, respectively. Lastly, the fuzzy aggregation function is reconstructed according to the importance of the fuzzy target and fuzzy constraint models. The optimal control decision with different possibility levels and importance can be obtained using the swarm intelligence algorithm. The case study indicates that the fuzzy aggregation function of radon exhalation has an upward trend with the increase of the cut set, and fuzzy optimization provides the optimal decision-making database of radon treatment and prevention under different decision-making criteria.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1161-1164
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• 1996

In this paper, a parameter optimization technique for a mobile robot navigation is discussed. Authors already have proposed a navigation algorithm for mobile robots with sonar sensors using fuzzy decision making theory. Fuzzy decision making selects the optimal via-point utilizing membership values of each via-point candidate for fuzzy navigation goals. However, to make a robot successfully navigate through an unknown and cluttered environment, one needs to adjust parameters of membership function, thus changing shape of MF, for each fuzzy goal. Furthermore, the change in robot configuration, like change in sensor arrangement or sensing range, invokes another adjusting of MFs. To accomplish an intelligent way to adjust these parameters, we adopted a genetic algorithm, which does not require any formulation of the problem, thus more appropriate for robot navigation. Genetic algorithm generates the fittest parameter set through crossover and mutation operation of its string representation. The fitness of a parameter set is assigned after a simulation run according to its time of travel, accumulated heading angle change and collision. A series of simulations for several different environments is carried out to verify the proposed method. The results show the optimal parameters can be acquired with this method.

• 한국수자원학회논문집
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• 제46권2호
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• pp.171-182
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• 2013

본 논문은 퍼지집합이론을 이용한 다기준 의사결정(MCDM) 과정에 관한 연구이며, 농업용 저수지의 수자원계획 평가에 관한 가장 합리적이고 효율적인 방법을 찾기 위해 FAHP를 이용하여 각각의 대안들에 대한 우선순위를 정하였다. 농업용 저수지의 추가저수량 확보를 위해 의사결정자 및 수혜자가 동시에 만족하는 조건을 조사하여 6개의 주 기준을 설정하고 이에 따른 10개의 대안을 설정하여 우선순위를 결정하고자 하였으며, 우선순위를 결정에서의 불확실성과 모호성을 규명하기 위해 퍼지수와 언어변수를 정의하였다. 또한 적절한 의사결정모형의 제시를 위해 의사결정 방법에 따른 분석결과를 비교 검토하였으며 FAHP 기법 적용의 타당성을 논의하였다.

• 대한인간공학회지
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• 제17권1호
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• pp.37-46
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• 1998

A human sensibility ergonomics design supporting system was applied to the product development for the customer's satisfaction based on ergonomics technology. The system is composed of three major subsystems such as customer's sensibility analysis, inference mechanism, and presentation technology. The main approaches of the system are to analyze customer's sensibilities and to translate them into product design elements. The purpose of this paper is to develop a design supporting system in which the relationship between customer's sensibility and product design elements is reasoned by a MADM(Multi-Attribute Decision Making) fuzzy model. In this model, three variables such as multiple correlation coefficients, partial correlation coefficients, and category scores were used in reasoning process. The weighted value of the words were also considered in fuzzy decision process. As a case study, the design supporting system with the MADM fuzzy model was applied to the personnel computer design.

• 대한토목학회논문집
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• 제33권3호
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• pp.917-926
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• 2013

본 연구는 로버스트 우선순위 결정을 위한 퍼지 다기준 의사결정기법의 타당성을 수자원 계획수립 문제에 적용하여 제시하였다. 즉 일반적인 다기준 의사결정 기법인 가중합계법, 계층화분석과정, 수정계층화분석과정, TOPSIS 방법과 퍼지가중합계법, 퍼지계층화분석과정, 퍼지수정계층화분석과정, 퍼지 TOPSIS 방법을 사용하여 결과를 비교하였다. 이때 사용된 각 평가기준별 자료는 동일하게 표준화되었으며 각 가중치도 동일한 방법으로 결정되었다. 분석결과 다기준 의사결정방법에 따라 조금씩 다른 순위가 도출되었으나, 퍼지 다기준 의사결정기법을 사용할 경우 사업들의 순위 변동성이 퍼지를 사용하지 않을 때보다 크지 않아 보다 일관된 순위를 유도하였다. 따라서 사업의 우선순위를 결정하는 문제에서 자료와 가중치의 불확실성을 고려할 수 있는 퍼지 다기준 의사결정기법을 활용해서 방법의 변화로 인한 순위의 변동성을 최소화해서 로버스트 순위를 결정하는 것이 보다 효과적이다.

• 대한산업공학회지
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• 제16권2호
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• pp.37-44
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• 1990

In selecting the best project in multi-criteria decision making problems, the imperfect information of consequence and the vague preference of the decision maker(DM) would make the decision analysis more complex together with the conflict of several criteria. In this context, a method is proposed to deal the fuzzy information mentioned before instead of reducing it to a single representative value. And, based on the given imprecise information, projects are ranked completely or partially according to DM's vague preference. The procedure consists, for each pair of projects, of calculating the degree of supporting over all criteria and the degree of opposing with respect to each criterion for their outranking relation. Together with weights for each criterion, these indices produce fuzzy outranking relations for each pair of projects. And a complete or partial ranking of projects is obtained according to outranking degrees considering the interdependence among projects.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 추계 학술발표회 논문집
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• pp.64-68
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• 1998

This paper discusses the potential application of fuzzy set theory to the decision-making in the area of radioactive waste management. the approach proposed in this study is based on the concepts of fuzzy set theory and the hierarchical structure analysis. The linguistic variables and fuzzy numbers are used to aggregate the decision maker's subjective assessments of the decision criteria and of the decision alternatives with respect to these criteria. For each alternative, the fuzzy appropriateness index is evaluated to obtain the final score. Using total integral value method, one of methods for ranking fuzzy numbers, the fuzzy appropriateness indices are ranked. As a case problem, selection of the most suitable option for spent fuel storage is illustrated.