• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.315-320
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• 1997

Rule minimization technique adapted from rough set theory was applied to remove redundant knowledge which is not necessary to make a knowledge base. New algorithm to diagnose fault using Improved Fuzzy Cognitive Maps(I-FCMs), and Fuzzy Associative Memory(FAM) is proposed. I-FCM[22] is superior to gathering knowledge from many experts and descries dynamic behaviors of systems very well. I-FCM is not only a knowledge base, but also a inference engine. FAM has learning capability like neural network[12]. Rule minimization and composition of I-FCM and FAM make it possible to construct compact knowledge base and breaks the border between inference engine and knowledge base.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.1-8
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• 1999

In the logic where we study the principle and method of human, the binary logic with the proposition which has one-valued property that it can be assigned the truth value 'truth'or 'false'. Although most of the traditional binary logic which was drawn by human includes fuzziness hard to deal with, the knowledge for expressing it is not precise and has less degree of credit. This study uses multi-valued logic in order to slove the problem above that .When compared with the data processing ability of the binary logic, Multi-valued logic has an at a high speed. Therefore the Inference can be possible by minimization multi-valued logic in stead of using the information stead of using the information system based on the symbolic binary logic.

• KSCI Review
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• v.2 no.2
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• pp.57-62
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• 1996

• Journal of the Korean Statistical Society
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• v.24 no.2
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• pp.453-470
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• 1995

We describe a constrained optimal classification rule for the case when the prior probability of an observation belonging to one of the two populations is unknown. This is done by suggesting a balanced design for the classification experiment and constructing the optimal rule under the balanced design condition. The rule si characterized by a constrained minimization of total risk of misclassification; the constraint of the rule is constructed by the process of equation between Kullback-Leibler's directed divergence measures obtained from the two population conditional densities. The efficacy of the suggested rule is examined through two-group normal classification. This indicates that, in case little is known about the relative population sizes, dramatic gains in accuracy of classification result can be achieved.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.9
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• pp.1103-1111
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• 1999

STACOM will be utilized to control substation voltage in the near future. Although STACOM shows good voltage regulation performance owing to its rapid and continuous response, it needs additional reactive power compensation device to keep control margin for emergency such as fault. ULTC transformer is one of good candidates. This paper presents a Kohonen Neural Network (KNN) based coordination control scheme of ULTC transformer and STACOM. In this paper, the objective function of the coordination control is minimization of both STACOM output and the number of switchings of ULTC transformer while maintaining substation voltage magnitude to the predefined constant value. This coordination, control is performed based on reactive load trend of the substation and KNN which offers optimal tap position in view of STACOM output minimization. The input variables of KNN are active and reactive power of the substation, current tap position, and current STACOM output. The KNN is trained by effective Iterative Condensed Nearest Neighbor (ICNN) rule. This coordination control applied to IEEE 14 bus system and shows satisfactory results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.293-300
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• 2011

A number of techniques have been developed for estimation of speed or position in motor drives. The accuracy of these techniques is affected by the variation of motor parameters such as the stator resistance, stator inductance or torque constant. This paper is proposed a neural network based estimator for torque and stator resistance and adaptive fuzzy learning contrroller(AFLC) for speed control in IPMSM Drives. AFLC is chaged fuzzy rule base by rule base modifier for robust control of IPMSM. The neural weights are initially chosen randomly and a model reference algorithm adjusts those weights to give the optimum estimations. The neural network estimator is able to track the varying parameters quite accurately at different speeds with consistent performance. The neural network parameter estimator has been applied to slot and flux linkage torque ripple minimization of the IPMSM. The validity of the proposed parameter estimator and AFLC is confirmed by comparing to conventional algorithm.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.2932-2934
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• 1999

In this paper, a scheme for recognition of handwritten digits using a multilayer neural network trained with the back-propagation algorithm using generalized delta rule is proposed. The neural network is trained with hand written digit data of different writers and different styles. One of the purpose of the work with neural networks is the minimization of the mean square error(MSE) between actual output and desired one. The back-propagation algorithm is an efficient and very classical method. The back-propagation algorithm for training the weights in a multilayer net uses the steepest descent minimization procedure and the sigmoid threshold function. As an error rate is reduced, recognition rate is improved. Therefore we propose a method that is reduced an error rate.

• Journal of Korea Multimedia Society
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• v.11 no.12
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• pp.1739-1748
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• 2008

When we conduct a data mining procedure on sample data sources, several rules are generated. But some rules are redundant or logically disjoint and therefore they can be removed. We suggest a new rule minimization algorithm inspired from logic synthesis to improve comprehensibility and eliminate redundant rules. The method can merge several relevant rules into one based on data mining and logic synthesis without high loss of accuracy. In case of two or more rules are candidates to be merged, we merge the rules with the attribute having the lowest information gain. To show the proposed method could be a reasonable solution, we applied the proposed approach to a problem domain constructing user preferred ontology in anti-spam systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1171-1177
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• 2010

This paper presents a robust design procedure for minimizing warpage in plastic injection-molded products, where the Pick-the-Winner rule based on Taguchi's Orthogonal Array experiments and the Design Space Reduction Method are integrated for optimization. Two-step optimization approach is applied to reduce warpage in the part design stage and additionally to minimize the warpage in the process conditions design stage. Taguchi's S/N ratio is introduced as a design metric to evaluate robustness against process variations. The effectiveness of proposed optimization process is shown with an example of warpage minimization problem.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.175-181
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• 2006

컴퓨팅 디바이스의 존재를 의식 하지 않고 원하는 서비스를 제공 받을 수 있는 유비쿼터스 환경하에서는 최소한의 HCI 또는 배제된 HCI 가 요구된다. 이러한 요구를 충족시키기 위해 효율적인 서비스를 제공하는 시스템들은 추론을 통해 사용자의 의도 파악 및 그에 따른 서비스를 제공 할 수 있으나 그것에 대한 정확한 판단은 실질적으로 달성하기 어렵다. 또 다른 접근 방법으로는 Event-Condition-Action (ECA) Rule 형태 기반으로써 명확한 Event Trigger 와 Event 발생시의 상황 조건을 기반으로 이미 기술된 서비스를 제공하는 것이다. ECA에 의한 서비스의 제공은 확률 기반의 추론을 통한 서비스 제공보다 더욱 명확한 서비스 제공의 판단이 가능하나 복잡한 환경에서 방대한 양의 발생 가능한 모든 Rule에 대한 기술은 많은 노력이 필요하거나 심지어는 그것이 불가능하다는 단점을 갖고 있다. 이에 본 논문은 이러한 문제를 해결하고자 효과적인 서비스 제공을 위한 ECA Rule 자동 생성 기법을 소개하고자 한다. 본 논고에서 제안하는 시스템은 사용자의 행동과 상황을 추적 및 저장하여 그 정보를 바탕으로XML 형태의 ECA Rule을 자동 생성하여 그를 바탕으로 동일한 조건 및 상황 발생시 이미 기술된 서비스를 제공한다. 이러한 과정은 ECA Rule 기반의 서비스 제공 운용에 있어 가장 취약점인 ECA Rule 작성에 대한 사용자의 노력을 Rule의 양에 상관없이 손쉽게 해결 할 뿐만 아니라 각 사용자 별 Rule을 생성함으로써 유비쿼터스 환경하에서의 개인화된 서비스를 효율적으로 제공할 것이다.