• 전자공학회논문지B
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• 제31B권6호
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• pp.43-52
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• 1994

A design method of rule-based fuzzy modeling is presented for the model identification of complex and nonlinear systems. The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of ``IF....,THEN...', using the theories of optimization theory , linguistic fuzzy implication rules and fuzzy c-means clustering. Three kinds of method for fuzzy modeling presented in this paper include simplified inference (type I), linear inference (type 2), and modified linear inference (type 3). In order to identify premise structure and parameter of fuzzy implication rules, fuzzy c- means clustering and modified complex method are used respectively and the least sequare method is utilized for the identification of optimum consequence parameters. Time series data for gas furance and those for sewage treatment process are used to evaluate the performance of the proposed rule-based fuzzy modeling. Comparison shows that the proposed method can produce the fuzzy model with higher accuracy than previous other studies.

• Journal of information and communication convergence engineering
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• 제14권2호
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• pp.97-105
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• 2016

With the increasing demand for interoperability among existing learning resource systems in order to enable the sharing of learning resources, such resources need to be annotated with ontologies that use different metadata standards. These different ontologies must be reconciled through ontology mediation, so as to cope with information heterogeneity problems, such as semantic and structural conflicts. In this paper, we propose an ontology-mapping technique using Semantic Web Rule Language (SWRL) to generate semantic mapping rules that integrate learning resources from different systems and that cope with semantic and structural conflicts. Reasoning rules are defined to support a semantic search for heterogeneous learning resources, which are deduced by rule-based inference. Experimental results demonstrate that the proposed approach enables the integration of learning resources originating from multiple sources and helps users to search across heterogeneous learning resource systems.

• 지능정보연구
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• 제13권3호
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• pp.17-29
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• 2007

웹 표준 언어인 XML에 기반한 각종 표준들을 바탕으로 소프트웨어 에이전트와의 인터페이스에 초점을 맞추고 있는 차세대 웹에서 소프트웨어 에이전트의 두뇌 역할을 수행하기 위한 추론엔진은 시맨틱 웹(Semantic Web)에서의 규칙 표현을 위한 언어인 SWRL(Semantic Web Rule Language)을 이해할 수 있어야 한다. 본 연구에서는 SWRL을 규칙 표현 방법으로 사용하고, OWL을 사실 표현 방법으로 사용하는 정방향 추론엔진인 SMART-F(SeMantic web Agent Reasoning Tools-Forward chaining inference engine)을 개발하고자 한다. 전통적인 규칙 추론 분야에서는 정방향 추론을 위하여 if-then 형태의 규칙을 네트워크 구조로 변환하여 정방향 규칙 추론의 효율성을 높인 Rete 알고리즘이 많이 사용되고 있다. 이를 시맨틱 웹 환경에 적용하기 위하여 SWRL 기반 정방향 추론을 위한 요구 기능을 분석하고, Rete 알고리즘에 도출된 차세대 시맨틱 웹의 요구 기능을 반영한 정방향 추론 알고리즘을 설계하였다. 또한, 유비쿼터스 환경에서의 각종 플랫폼의 독립성과 이식성을 확보하고 기기간의 성능 차이를 극복할 수 있도록 사실 베이스 및 규칙 베이스의 관리도구와 정방향 추론 엔진 등을 Java 컴포넌트로 개발하였으며, 이는 이미 개발된 역방향 추론엔진인 SMART-B와 규칙 베이스 및 사실 베이스를 완벽하게 호환 가능하므로 차세대 웹 환경에서의 지식 활용을 극대화시킬 것이다.

• 지능정보연구
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• 제9권2호
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• pp.19-38
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• 2003

In this research, we propose the mechanism to develop self-evolving expert systems (SEES) based on data mining (DM), fuzzy neural networks (FNN), and relational database (RDB)-driven forward/backward inference engine. Most researchers had tried to develop a text-oriented knowledge base (KB) and inference engine (IE). However, this approach had some limitations such as 1) automatic rule extraction, 2) manipulation of ambiguousness in knowledge, 3) expandability of knowledge base, and 4) speed of inference. To overcome these limitations, knowledge engineers had tried to develop an automatic knowledge extraction mechanism. As a result, the adaptability of the expert systems was improved. Nonetheless, they didn't suggest a hybrid and generalized solution to develop self-evolving expert systems. To this purpose, we propose an automatic knowledge acquisition and composite inference mechanism based on DM, FNN, and RDB-driven inference engine. Our proposed mechanism has five advantages. First, it can extract and reduce the specific domain knowledge from incomplete database by using data mining technology. Second, our proposed mechanism can manipulate the ambiguousness in knowledge by using fuzzy membership functions. Third, it can construct the relational knowledge base and expand the knowledge base unlimitedly with RDBMS (relational database management systems) module. Fourth, our proposed hybrid data mining mechanism can reflect both association rule-based logical inference and complicate fuzzy relationships. Fifth, RDB-driven forward and backward inference time is shorter than the traditional text-oriented inference time.

• Nuclear Engineering and Technology
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• 제22권2호
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• pp.128-138
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• 1990

본 논문에서는 원자로냉각재펌프 고장진단 전문가시스템 (ESRCP)에 대해 기술하였다. 이 시스템의 목적은 RCP의 고장진단과 함께 발전소 운전원에게 적절한 운전 조작 및 비상조치 사항 등을 알려주는데 있다. 진단을 위한 일차적 증상은 RCP 영역에 관련된 경보들이다. 경보처리는 Rule-based Deduction 또는 Priority Factor Operation에 의한다. 고장진단은 Rule-based Deduction이나 Bayesian Inference에 의해 수행된다. 각종 Sensor들의 측정값들은 정확한 원인을 진단하기 위해 필요로 하다 증상들이 부족하거나 불착실성을 나타낼 때는 Bayesian Inference로 고장을 진단한다.

• 한국CDE학회논문집
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• 제5권4호
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• pp.319-326
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• 2000

Expert systems using uncertain and ambiguous knowledge are not of the recent interests about uncertainty problem for performing inference similar to the decision making of a human expert. Human factors on rule-based systems often involve uncertain information. Expert systems had been used the methods of conflict resolution in a rule conflict situation, but this methods not properly solved the rule conflict. If a human expert appends a new rule to an original rule base, the rule base rightly causes a rule conflict. In this paper, the problem of rule conflict is regarded as one in which uncertainty of information is fundamentally involved. In the reduction of problem with uncertainty, we propose an enhanced rule ordering method, which improve the rule ordering method using Dempster-Shafer theory. We also propose a combinative index, which involve human factors of experts decision making.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.99-104
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• 2003

In this research, we proposed the mechanism to develop self evolving expert systems (SEES) based on data mining (DM), fuzzy neural networks (FNN), and relational database (RDB)-driven forward/backward inference engine. Most former researchers tried to develop a text-oriented knowledge base (KB) and inference engine (IE). However, thy have some limitations such as 1) automatic rule extraction, 2) manipulation of ambiguousness in knowledge, 3) expandability of knowledge base, and 4) speed of inference. To overcome these limitations, many of researchers had tried to develop an automatic knowledge extraction and refining mechanisms. As a result, the adaptability of the expert systems was improved. Nonetheless, they didn't suggest a hybrid and generalized solution to develop self-evolving expert systems. To this purpose, in this study, we propose an automatic knowledge acquisition and composite inference mechanism based on DM, FNN, and RDB-driven inference. Our proposed mechanism has five advantages empirically. First, it could extract and reduce the specific domain knowledge from incomplete database by using data mining algorithm. Second, our proposed mechanism could manipulate the ambiguousness in knowledge by using fuzzy membership functions. Third, it could construct the relational knowledge base and expand the knowledge base unlimitedly with RDBMS (relational database management systems). Fourth, our proposed hybrid data mining mechanism can reflect both association rule-based logical inference and complicate fuzzy logic. Fifth, RDB-driven forward and backward inference is faster than the traditional text-oriented inference.

• International Journal of Safety
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• 제4권2호
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• pp.12-17
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• 2005

This paper aims at the development of an knowledge base for an electrical fire cause diagnosis system using the entity relation database. The relation database which provides a very simple but powerful way of representing data is widely used. The system focused on database construction and cause diagnosis can diagnose the causes of electrical fires easily and efficiently. In order to store and access to the information concerned with electrical fires, the key index items which identify electrical fires uniquely are derived out. The knowledge base consists of a case base which contains information from the past fires and a rule base with rules from expertise. To implement the knowledge base, Access 2000, one of DB development tools under windows environment and Visual Basic 6.0 are used as a DB building tool. For the reasoning technique, a mixed reasoning approach of a case based inference and a rule based inference has been adopted. Knowledge-based reasoning could present the cause of a newly occurred fire to be diagnosed by searching the knowledge base for reasonable matching. The knowledge-based database has not only searching functions with multiple attributes by using the collected various information(such as fire evidence, structure, and weather of a fire scene), but also more improved diagnosis functions which can be easily wed for the electrical fire cause diagnosis system.

• 한국지능시스템학회논문지
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• 제12권1호
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• pp.7-13
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• 2002

퍼지이론의 응용은 대부분 퍼지추론을 이용하는 것이다. 그러나 퍼지추론은 입력변수의 수가 많아지거나 각 입력변수에 많은 수의 퍼지라벨을 설정할 경우 그 추론에 필요한 계산시간이 많아지게 되며 이러한 것은 컴퓨터 연산의 대수곱(arithmetic product)의 수에 의해 결정된다. 더구나 퍼지추론의 응용이 가장 활발한 퍼지제어분야에서는 이러한 추론시간은 실제 시스템에 적용 시 가장 큰 제약조건이 된다. 특히, 마이크로프로세서를 이용하거나 PC-based 제어기를 설계할 때 이러한 추론시간은 매우 중요한 문제가 된다. 본 논문에서는 이러한 추론시간을 효율적으로 줄이기 위해, 즉 추론 시 필요로 하는 곱 연산의 수를 줄이기 위하여 삼각형 소속함수를 이용하는 퍼지시스템에 적용 가능하며 정보의 손실이 발생되지 않는 간단한 고속 퍼지추론 알고리즘을 제안한다. 이것은 퍼지추론 시 입력상태공간의 분할과 간단한 기하학적 해석을 통해 얻어지는 것이며 결과적으로 퍼지규칙의 수를 줄이는 것과 같다.

• 한국전자거래학회지
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• 제12권1호
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• pp.99-122
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• 2007

규칙 기반 시스템은 업무 담당자의 비즈니스 노하우 및 전문 지식에 대한 처리는 물론, 기업의 비즈니스 로직까지 처리하여 새로운 비즈니스 모델 변화와 개선요구에 대해 즉각적으로 대응할 수 있는 규칙 기반 추론 엔진으로, 최근 다양한 산업으로의 적용이 시도되고 있다. 이에 이 논문에서는 규칙 기반 시스템 적용 사례의 일환으로, 다양한 소비자 니즈, 수많은 종류의 상품, 그리고 시시각각 변하는 대내외 환경에 민감하게 영향을 받는 보험 산업에서의 효율적인 보험 상품 추천과 설계를 위한 규칙 기반의 보험 상품 추천 및 설계 시스템을 설계하고 구현하고자 한다. 개발된 시스템은 퍼지추론 과정을 통해 고객의 개인정보와 기존 가입고객의 가입정보를 이용하여 보험상품 설계를 원하는 고객에게 맞춤형 보험상품을 추천하고 설계하고자 한다. 이러한 시도는 향후 보험 산업에 있어서 상품에 대한 다양한 고객들의 니즈를 즉각적으로 판단하고 대응하여 보다 정확하고, 고객 개개인의 욕구에 맞는 맞춤형 상품추천 및 설계를 위한 핵심 기술로서 자리 잡을 수 있을 것으로 기대된다.