• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.9
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• pp.423-429
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• 2001

This paper proposes adaptive impedance control algorithm using fuzzy inference when robot contacts with its environments. The characteristics of the adaptive impedance controller is to adapt with parametric uncertainty and nonlinear conditions. The control algorithm is to join impedance controller with fuzzy inference engine. The proposed control method overcomes the problem of impedance controller using gain-tuning algorithm of fuzzy inference engine. We implemented an experimental set-up consisting of environment-generated one-link robot system and DSP system for controller development. We apply the adaptive fuzzy impedance controller to one-link root system, and it shows the good performance on regulating the interactive force in case of contacting with arbitrary environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2157-2164
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• 2011

In this paper, we introduce a new category of fuzzy inference system based on Type-2 fuzzy c-means clustering algorithm (T2FCM-based FIS). The premise part of the rules of the proposed model is realized with the aid of the scatter partition of input space generated by Type-2 FCM clustering algorithm. The number of the partition of input space is composed of the number of clusters and the individual partitioned spaces describe the fuzzy rules. Due to these characteristics, we can alleviate the problem of the curse of dimensionality. The consequence part of the rule is represented by polynomial functions with interval sets. To determine the structure and estimate the values of the parameters of Type-2 FCM-based FIS we consider the successive tuning method with generation-based evolution by means of real-coded genetic algorithms. The proposed model is evaluated with the use of numerical experimentation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.69-76
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• 2003

In this paper, a novel speed control system that implements the fuzzy logic controller(FLC) is proposed. Fuzzy controller is shown more excellent efficency than a conventional controllers in the strength aspect and non-linear controller using IF-THEN rule which can control without process the accurate mathematical modeling about induction motor. But we cannot expect that conventional fuzzy controller divide equally the space of input and output parameter and use the certain shape of triangle membership function. Therefore to develop the efficiency of conventional fuzzy controller, We need to scale the range of membership functions. In this study, proposed fuzzy controller has the ability controlling scale of membership functions using by output scaling factor.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.113-120
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• 1994

The dynamic characteristics of turning processes are complex, non-linear and time-varying. Consequently, the conventional techniques based on crisp mathematical model may not guarantee cutting force regulation. This paper presents a fuzzy controller which can regulate cutting force in turning process under varying cutting conditions. The fuzzy control rules are extablished from operator experience and expert knowledge about the process dynamics. Regulation which increases productivity and tool life is achieved by adjusting feedrate according to the variation of cutting conditions. The performance of the proposed controller is evaluated by cutting experiments in the converted conventional lathe. The results of experiments show that the proposed fuzzy controller has a good cutting force regulation capability in spite of the variation of cutting conditions.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.28-38
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• 1995

The flank wear at the minor cutting edge significantly affects the geometric accuracy and surface roughness in finish machining. A fuzzy estimator based on a fuzzy inference algorithm with a max-min composition rule is introduced to evaluate the minor flank wear length. The features sensitive to minor flank wear are extracted from the dispersion analysis of a time series AR model of the feed directional acceleration signal. These features, dispersions, are used for constructing linguistic rules, and then the fuzzy inferences are carried out with test data sets collected under various cutting conditions. The proposed system turns out to be effective for estimating minor flank wear length.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.169-175
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• 2011

The adaptive neuro-fuzzy inference system (ANFIS) based automatic control system framework was proposed for integrated environment management of ubiquitous plant factory which can collect information of crop cultivation environment and monitor it in real-time by using various environment sensors. Installed wireless sensor nodes, based on the sensor network, collect the growing condition's information such as temperature, humidity, $CO_2$, and the control system is to monitor the control devices by using ANFIS. The proposed automatic control system provides that users can control all equipments installed on the plant factory directly or remotely and the equipments can be controlled automatically when the measured values such as temperature, humidity, $CO_2$, and illuminance deviated from the decent criteria. In addition, the better quality of the agricultural products can be gained through the proposed automatic control system for plant factory.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.63-76
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• 2006

For a private toll road project, deciding optimal toll is an important element of economic analysis for the project and a challengeable work. In this study, the optimal toll of a private toll bridge, Geoga Bridge which connects Geoje Island of Gyeongnam Province and Gaduk Island of Busan was estimated using Stated Preference (SP) data. The SP data were collected by interviewing the passenger car drivers travelling on the National Road 14. They are latent users of the bridge. A fuzzy approximate reasoning model to estimate the optimal toll was built using the SP data. For the input variable of the model, the saved travel time and toll level were employed and the diversion rate to the bridge was employed for the output variable. The diversion rates for each toll level and saved travel time were estimated and the toll level which had maximized the toll revenue was decided as optimal toll. The optimal toll was tested by comparing with the average pay rate of passenger car drivers. Since the optimal toll for passenger cars at one hour saving, the 6,250 won is about 50 % of the average pay rate of passenger car divers, the toll was evaluated not to be high. The technique employed in this study may be used for the estimation of the optimal tolls for other kinds of vehicles.

• Journal of KIISE:Software and Applications
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• v.29 no.8
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• pp.565-572
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• 2002

학습과 추론을 위하여 유용한 방법으로 퍼지연상기억장치가 있다. 본 논문에서는 보다 효과적으로 추론결과를 유도하기 위하여 퍼지연상기억장치를 학습하는 단계에서 오류 역전파를 통하여 노드들 사이의 연결가중치를 재조정하는 방법과 퍼지규칙들을 간결화하는 방법을 제안한다. 제안된 방법은 비디오 데이타의 장면전환을 검출하는 분야에 적용하여 성능평가를 수행한다.

• Korean Journal of Cognitive Science
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• v.3 no.2
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• pp.249-270
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• 1992

The purpose of this paper is to classify the types of input characters,printed Hangul characters,using Maximum Run Length Projection(MRLP)that is used to extract features of input character.Because the number of Hangul characters is large and its structure is complex,there exists close similarities among characters.This paper,therefore,tried to increment the type classification rate using fuzzy resoning.The Maximum Run Length Projection is very immune to noise,and also useful to extracting the demanding information efficiently.In a test case with the most frequently use 917 printed Hangul characters,it achieved 98.58%correct classification rate.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.64-67
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• 2002

인터넷 기반의 전자상거래에 참여하는 판매자와 구매자는 가격, 마진 등 다양한 거래조건들을 가지고 협상 (negotiation)을 진행하는 경우가 많다. 그러나, 기존연구에서는 대부분 가격과 거래량과 같은 두 개 미만의 정량적 (quantitative)인 거래조건을 중심으로 협상을 진행하는 방안을 중점적으로 다루었다. 그 결과, 단순한 실험적 문제에 대해서만 협상지원이 가능했고, 실세계의 전자상거래 협상과정에서 발생할 수 있는 다중 협상 요인들간의 동적인 변화를 고려하지 못했다는 지적을 피하기 어렵다. 본 연구에서는 이러한 점에 주목하여 전자상거래 판매자와 구매자가 웹 상에서 다차원적인 거래조건을 가지고 실시간으로 시뮬레이션을 하면서 보다 동적으로 협상을 수행할 수 있도록 퍼지 멤버심 함수와 AHP 추론기법을 이용한 전자상거래 협상지원 (Fuzzy AHP Negotiation support. FAHP-NEGO) 메커니즘을 제안하고자 한다. 실험결과, 협상에 필요한 정량적인 값과 판매자와 구매자의 주관적인 의사결정 행동양식이 반영된 보다 동적인 협상을 진행할 수 있었다. 따라서, 본 연구결과는 향후, 전자상거래 협상에 있어서 보다 현실적인 협상을 지원할 수 있을 것으로 기대한다.