• Journal of Korea Society of Industrial Information Systems
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• v.4 no.2
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• pp.7-13
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• 1999

This paper propose a fuzzy regression method using fuzzy neural networks when a membership value is attached to each input -output pair. First, an architecture of fuzzy neural networks with fuzzy weights and fuzzy biases is shown. Next, a cost function is defined using the fuzzy output from the fuzzy neural network and the corresponding target output with a membership value. A learning algorithm is derived from the cost function. The derived learning algorithm trains the fuzzy neural network so that the level set of the fuzzy output includes the target output. Last, the proposed method is applied to the quality evaluation problem of injection molding

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.65-76
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• 2002

This study is realized using fuzzy evaluation and AHP(the analytic hierarchy process) for the optimum search of traffic route and estimated by the quantitative analysis in the vague subjective judgement. It is different from classical route search and noticed thinking method of human. Appraisal element, weight, appraisal value of route is extracted from basic of the opinion gathering fur the driving expert and example of route model was used for the finding of practice utility. Model assessment was performed attribute membership function making of estimate element, estimate value setting, weight define by the AHP, non additive presentation of weight according to $\lambda$-fuzzy measure, Choquet fuzzy integral.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.153-159
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• 2009

The steel balls are core elements between inner part and outer part in a bearing system. The degree of goodness of the steel balls has been visually processed by human beings. In this paper we propose a new method that uses image processing algorithm and fuzzy logic theory. We use fuzzy inference engine and fuzzy Choquet integral algorithm in the proposed system. We first distinguish the defects of the steel balls by an image processing algorithm. And then the degree of the defects is classified by a fuzzy logic system. We perform some simulations to show the effectiveness and feasibility of the proposed system.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.391-395
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• 2005

In this paper, the new evaluation system for water quality pollution is implemented using fuzzy integral based on the conventional evaluation criterions and their evaluation factors and this is the first phase in the whole water quality pollution evaluation system development. In the final evaluation for water quality pollution the factors like BOD, COD, SS, T-N, and T-P are taken into overall accounts. It is found that the final evaluation can be represented in a linear combination of respective factor evaluation when each factor is independent one another, With respect to the combination patterns the fuzzy measurement is defined and the fuzzy integral is taken. As a result this approach shows stable and reliable evaluation for the water quality pollution evaluation system development.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.151-156
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• 2008

This paper presents the stability analysis and design for a sampled-data fuzzy control system with neutral type of time delay, which is formed by a nonlinear plant and a sampled-data fuzzy controller connected in a closed loop. The sampling activity and neutral type of time delay will complicate the system dynamics and make the stability analysis much more difficult than that for a pure continuous-time fuzzy control system. Based on the fuzzy-model-based control approach, LMI(linear matrix inequality)-based stability conditions are derived to guarantee the nonlinear networked system stability. An application example will be given to show the merits and design a procedure of the proposed approach.

• Journal of Korean Society of Transportation
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• v.22 no.1 s.72
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• pp.73-82
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• 2004

신호 교차로에서 포화차두시간에 영향을 미치는 영향인자는 도로조건, 교통조건, 환경조건으로 분류된다. 이러한 요인들의 복합적인 관계가 포화차두시간에 영향을 미친다. 현재 포화교통류율은 이상적인 조건일 때의 포화차두시간을 산출하고, 이를 이용해서 기본 포화교통류율을 구하고, 여기에 좌 우회전, 차로폭, 경사, 중차량 보정계수을 고려함으로써 특정 차로군의 포화교통류율을 산정하고 있다. 포화차두시간에 영향을 미치는 인자들 중에서 정량적으로 나타내기 어려운 인자 즉, 퍼지적 성격을 가진 인자들은 고려하지 않고 있다. 따라서 본 연구에서는 퍼지 근사추론 방법을 이용하여 정성적 인자의 영향을 고려한 모형을 구축하였다. 모형의 입력자료는 강우조건과 주변밝기의 정도, 중차량 구성비의 언어적 표현를 사용하였다. 이러한 변수들에 대하여 설문조사를 통해서 퍼지집합의 멤버쉽함수를 설정하였으며. 이에 기초하여 교차로에서 각 조건별로 포화차두시간을 관측하였다. 이러한 현장 관측치를 바탕으로 퍼지 제어규칙을 설정하고 모형을 구축하였다. 모형의 평가는 추론치와 실측치를 비교함으로써 이루어 졌으며, 결정계수인 $R^2$와 평균절대오차(MAE)와 평균제곱오차(MSE)를 사용하여 분석한 결과 본 모형의 설명력이 높은 것으로 평가되었다. 본 연구의 과정에서 강우에 의한 교통용량 감소는 중차량 구성비가 클수록 주변밝기의 정도가 나쁠수록 더욱 큰 것으로 나타났으며 그 감소율은 5.3%에서 21.8%에 이르는 넓은 범위의 값을 보였고. 주변밝기 정도에 따른 교통용량 감소는 4.7$\sim$7.5% 수준으로 나타났다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.573-580
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• 2006

The Saturation headway is a major parameter in estimating the intersection capacity and setting the signal timing. But Existing algorithms are still far from being robust in dealing with factors related to the variation of saturation headways at signalized intersections. So this study apply the fuzzy inference system using ANFIS. The ANFIS provides a method for the fuzzy modeling procedure to learn information about a data set, in order to compute the membership function parameters that best allow the associated fuzzy inference system to track the given input/output data. The climate conditions and the degree of brightness were chosen as the input variables when the rate of heavy vehicles is 10-25 %. These factors have the uncertain nature in quantification, which is the reason why these are chosen as the fuzzy variables. A neuro-fuzzy inference model to estimate saturation headways at signalized intersections was constructed in this study. Evaluating the model using the statistics of $R^2$, MAE and MSE, it was shown that the explainability of the model was very high, the values of the statistics being 0.993, 0.0289, 0.0173 respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.411-419
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• 1999

In this paper, we propose an evaluation model of systems level using modified eigenvector method and fuzzy subordination relations. This model is desibmed to evaluate the level of system in enterprise. In here. modified eigenvector method is proposed to compute the weights of each criteria in two evaluation group. Also, fuzzy subordination relations is used to evaluate the relationship between the criteria by painvise comparison. In this paper. we can get the evaluated score for the present level of system. This method will help to manage and improve the systems. We show the efficiency of the this method by means of a case study for evaluation problem of environmental management systems.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.177-184
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• 2004

The purpose of this study is to identify and evaluate the competitiveness of container ports in ASEAN(Association of Southeast Asian Nations) and Korea, which plays a leading role in basing the hub of international logistics strategies at the onset of the 21st century. Its ultimate purpose is to consider the relevant policy-making by comparing the competitiveness of ASEAN and Korea's container ports. This paper adopted the HFP method, which is an empirical analysis that evaluated the port competitiveness by quantifying it a, a qualitative attribute in the aforementioned area, where both ASEAN and Korea vie with each other for increasing container throughput. The results of this study showed that Singapore ranked the first in the subject of study in view of the competitiveness, followed by Busan(2) and Manila(2) as a leading group of the relevant ports in international logistics strategies. This analytic evaluation contributes to the empirical approach applied to policy-making by the HFP method, which is the newest research technique in social science through the comparative study of port competitiveness between ASEAN and Korea.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.411-415
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• 2003

This paper compared fuzzy thesaurus through query extension with existent thesaurus and direct matching retrieval etc. Performance of fuzzy thesaurus is evaluated by the recall and precision through simulation. An experiment did through assessment that use critical value, query extension, and reusability satisfaction. As a result of the experiment, we knew component retrieval efficiency of fuzzy thesaurus excels.