• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.774-779
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• 2001

If rotating machinery have a fault, we can detect it using vibration or noise signals. However some maintenance engineers who doesn't have expert knowledge, needs the help of vibration experts for diagnosing rotating machinery. But qualified experts are rare, therefore we have been developed the case based reasoning (CBR) system which is able to manipulate the past experiences of vibration diagnosis experts. In the CBR system, the maintenance engineers can retrieve too information from previous cases which are most similar to new problem and they can solve new problem using solutions from the previous cases. In this paper, we propose a new method which is the case retrieval of CBR system using Petri net and we also applied it to diagnosis for electric motors as a practical problem.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.285-288
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• 2006

Most previous studies on improving the effectiveness of CBR have focused on the similarity function aspect or optimization of case features and their weights. However, according to some of the prior research, finding the optimal k parameter for the k-nearest neighbor (k-NN) is also crucial for improving the performance of the CBR system. Nonetheless, there have been few attempts to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors that combine, as well as the weight of each feature. The new model is applied to the real-world case of a major telecommunication company in Korea in order to build the prediction model for the customer profitability level. Experimental results show that our GA-optimized CBR approach outperforms other AI techniques for this mulriclass classification problem.

• The KIPS Transactions:PartB
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• v.9B no.3
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• pp.263-270
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• 2002

Most conventional systems of fire fighting control in a ship have been based on rule-based system in which expert knowledges are expressed with production rules. Renewing and adding of rules is needed continuously for the improvement of the system capability in an already build-up system and such adding and renewing procedures could hinder users from fluent utilization of a system. The author proposes an advanced fire fighting control intelligent system (A-FFIS) using rule-based and carte-based reasoning by clustering to implement conventional hybrid system (H-FFIS). Compared with H-FFIS, new approach with A-FFIS shows that the system proposed here improves fire detection rate and reduces fire detection time.

• Journal of The Korean Association For Science Education
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• v.14 no.2
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• pp.133-142
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• 1994

Many students have misconceptions that upward direction force act on the object which is moving upward after being thrown vertically upward, and no force act on the object at the top of its flight because the object stop or don't' move at the top. To change these misconceptions, in this study, deductive reasoning tasks were used, and student's responses to the tasks were analyzed. In the first part of this study, student's prior conceptions about force and motion and student's deductive reasoning abilities were investigated. And the second part, student's explanations were classified to either the premise-based or idea-based explanation. In the case of the object which is moving upward, 62% of students who had misconception changed their misconceptions to physically correct concept, but, only 24% of students changed their misconceptions for the object at the top. For the first task, more students changed their misconceptions when they made responses based on premises than based on their own idea(p<.05), so, the first task can be helpful for conceptual change. 40% students changed their own misconception by reasoning deductively based on premises provided in the first task, but only 17% students changed by the second task. Student's reasoning abilities investigated in the first part of this study did not affect the conceptual change. Four students for the first task and one student for the second task did not change their misconception even though they made premise-based explanation and had high reasoning abilities.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.91-109
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• 2004

This study investigates the effectiveness of a hybrid approach using fuzzy sets that describe approximate phenomena of the real world. Compared to the other existing techniques, the approach handles inexact knowledge in common linguistic terms as human reasoning does it. Integration of fuzzy sets with case-based reasoning (CBR) is important in that it helps to develop a successful system far dealing with vague and incomplete knowledge which statistically uses membership value of fuzzy sets in CBR. The preliminary results show that the accuracy of the integrated fuzzy-CBR approach proposed for this study is higher that of conventional techniques. Our proposed approach is applied to corporate bond rating of Korean companies.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.486-500
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• 2013

This study is conducted to examine how epistemic reasoning and argument structures of students vary according to data sources used in the process of argumentation implemented in the context of inquiry. To this end, three argument tasks using first-hand data and three argument tasks using second-hand data were developed and applied to the unit on 'Nutrition of Plants' for first year middle school students. According to the results of this study, epistemic reasoning of students manifested during the process of argumentation and varied according to data sources. While most students composed explanations with phenomenon-based or relation-based reasoning in argumentation using first-hand data, all the small groups composed explanations that included model-based reasoning in argumentation using second-hand data. In the case of arguments including phenomenon-based or relation-based reasoning, students described only observable characteristics, with warrants omitted from arguments in many cases. On the other hand, in the case of arguments that included model-based reasoning, explanations were composed by combining the results of observations with theoretical knowledge, with warrants more apparent in their arguments.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.14-18
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• 2002

전자상거래가 점차 활성화됨에 따라 다양한 형태의 쇼핑몰들이 구축되고 있으나, 구매자가 상품을 구입하는데 있어 구매자 기호와 요구에 적합한 상품을 검색하기에는 미흡한 실정이다. 따라서, 본 논문에서는 CBR(Case Based Reasoning)과 RBR(Rule Based Reasoning)을 통합한 검색에이전트와 사용자 프로파일과 선호도를 관리하는 사용자 에이전트로 이루어진 멀티 에이전트를 이용하는 CARUBA 시스템을 설계하고, 검색에이전트가 사용자에이전트에서 보낸 정보를 이용하여 유사도를 산출하여 구매자의 요구에 적합한 상품을 신속하게 추천할 수 있는 방법을 제안한다

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.163-170
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• 2005

Urban transit is a complex system that is combined electrically and mechanically, it is necessary to construct maintenance system for securing safety accompanying high-speed driving and maintaining promptly. Expert system is a computer program which uses numerical or non-numerical domain-specific knowledge to solve problems. In this research, we intend to develop the expert system which diagnose failure causes quickly and display measures. For the development of expert system, standardization of failure code classification system and creation of BOM(Bill Of Materials) have been first performed. Through the analysis of failure history and maintenance manuals, knowledge base has been constructed. Also, for retrieving the procedure of failure diagnosis and repair linking with the knowledge base, we have built RBR(Rule Based Reasoning) engine by pattern matching technique and CBR(Case Based Reasoning) engine by similarity search method. This system has been developed based on web to maximize the accessibility.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.143-147
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• 2010

Due to the diversification and complication of construction projects, controlling risks from the early design-planning phase gives huge impact on success of the construction project. As a part of managing uncertainties it is also important to estimate the project cost several times. Especially, estimating project cost in the early stage gives effects on making a budget for projects. This study estimated the apartment project cost using case-based reasoning(CBR), which is the process of solving new problems based on the past problems. For this, we deduced the apartment cost influence factors which can be gathered in the early stage of project. Based on the factors we established the database for apartment project and calculated the attribute value, attribute similarity and case similarity. Although we retrieve the most similar case from the database, it is very hard to utilize it directly due to the uniqueness of each project. So, Genetic Algorithm(GA) was applied in revising the cost of the retrieved-case. Therefore, the accuracy of the prediction was improved by GA optimization.

• The Journal of Information Systems
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• v.8 no.1
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• pp.27-44
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• 1999

Case-Based Reasoning(CBR) offers a new approach for developing knowledge based systems. CBR has several research issues which can be divided into two categories : (1) static issues and (2) dynamic issues. The static issues are related to case representation scheme and case data model, that is, focus on casebase which is a repository of cases. The dynamic issues, on the other hand, are related to case retrieval procedure and problem solving process, i.e. case adaptation phase. This research is forcused on retrieval procedure Traditional query processing accepts precisely specified queries and only provides exact answers, thus requiring users to fully understand the problem domain and the casebase schema, but returning limited or even null information if the exact answer is not available. To remedy such a restriction, extending the classical notion of query answering to approximate query answering(AQA) has been explored. AQA can be achieved by neighborhood query answering or associative query answering. In this paper, neighborhood query answering technique is used for AQA. To reinforce the CBR process, a new retrieval procedure(cooperative CBR) using neighborhood query answering is proposed. An neighborhood query answering relaxes a query scope to enlarge the search range, or relaxes an answer scope to include additional information. Computer Aided Process Planning(CAPP) is selected as cooperative CBR application domain for test. CAPP is an essential key for achieving CIM. It is the bridge between CAD and CAM and translates the design information into manufacturing instructions. As a result of the test, it is approved that the problem solving ability of cooperative CBR is improved by relaxation technique.