• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
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• pp.17-20
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• 2002

This paper proposes a new 75 fuzzy model approximation method which reduces error in nonlinear fuzzy model approximation over the V-type decision rules. Employing rational Bezier curves used in computer graphics to represent curves or surfaces, the proposed method approximates the decision rule by constructing a tractable linear equation in the highly non-linear fuzzy rule interval. This algorithm is applied to the self-adjusting air cushion for spinal cord injury patients to automatically distribute the patient's weight evenly and balanced to prevent decubitus. The simulation results indicate that the performance of the proposed method is bettor than that of the conventional TS Fuzzy model in terms of error and stability.

• 대한전기학회논문지:전력기술부문A
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• 제49권4호
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• pp.177-184
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• 2000

In this paper, we proposes a method for assessing the effect of voltage sag in power distribution systems using fuzzy model. The proposed method is based on the reliability data of distribution system and specified computer business equipment manufacturer association(SCBEMA) curve that express the representative power acceptability curve by voltage sag for each customer type. The SCBEMA curves are made by using the CBEMA curves obtained from the experiment for the customers sensitive equipment. In order to transform SCBEMA curves to the differential damage by voltage sag, a fuzzy model is used. The proposed fuzzy model is composed to reflect two parameters of customers damage by voltage sag. One is the duration and magnitude of voltage sag and the other is the different risk due to the customer types. The Monte Carlo simulation method and the historical reliability data in KEPCO ae used for case studies.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권4호
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• pp.305-312
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• 2014

This paper discusses real-time peak shaving algorithms for a large-scale battery energy storage system (BESS). Although several transmission and distribution functions could be implemented for diverse purposes in BESS applications, this paper focuses on a real-time peak shaving algorithm for an energy time shift, considering wind power generation. In a high wind penetration environment, the effective load levels obtained by subtracting the wind generation from the load time series at each long-term cycle time unit are needed for efficient peak shaving. However, errors can exist in the forecast load and wind generation levels, and the real-time peak shaving operation might require a method for wind generation that includes comparatively large forecasting errors. To effectively deal with the errors of wind generation forecasting, this paper proposes a real-time peak shaving algorithm for threshold value-based peak shaving that considers fuzzy wind power generation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1949-1954
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• 2005

One of control methods for underactuated manipulators is known as a switching control which selects a partially-stable controller using a prespecified switching rule. A switching computed torque control with a fuzzy energy region method was proposed. In this approach, some partly stable controllers are designed by the computed torque method, and a switching rule is based on fuzzy energy regions. Design parameters related to boundary curves of fuzzy energy regions are optimized offline by a genetic algorithm (GA). In this paper, we discuss on parameters obtained by GA. The effectiveness of the switching fuzzy energy method is demonstrated with some simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1085-1087
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• 1999

In this paper, we propose the method for assessing the effect of voltage sag in power distribution system using fuzzy risk assessment model. The proposed method is based on SCBEMA curve that expresses the representative susceptibility curve by voltage sag for each customer type. These corves are made using the CBEMA curves obtained from the experiment for the customers'sensitive equipment. In order to transform SCBEMA curves to the probability damage by voltage sag, the fuzzy risk assessment model is used in this paper. Case studies were performed to analyze the effect of voltage sag by varying parameters. The Monte Carlo simulation method and the historical reliability data in KEPCO are used for case studies.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권2호
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• pp.148-153
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• 2007

This paper deals with implementing a steganography based multi-modal biometric system. For this purpose, we construct a multi-biometrics system based on the face and iris recognition. Here, the feature vector of iris pattern is hidden in the face image. The recognition system is designed by the fuzzy-based Linear Discriminant Analysis(LDA), which is an expanded approach of the LDA method combined by the theory of fuzzy sets. Furthermore, we present a watermarking method that can embed iris information into face images. Finally, we show the advantages of the proposed watermarking scheme by computing the ROC curves and make some comparisons recognition rates of watermarked face images with those of original ones. From various experiments, we found that our proposed scheme could be used for establishing efficient and secure multi-modal biometric systems.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권1호
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• pp.71-76
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• 2007

This paper deals with implementing a steganography based multi-modal biometric system. For this purpose, we construct a multi-biometrics system based on the face and iris recognition. Here, the feature vector of iris pattern is hidden in the face image. The recognition system is designed by the fuzzy-based Linear Discriminant Analysis(LDA), which is an expanded approach of the LDA method combined by the theory of fuzzy sets. Furthermore, we present a watermarking method that can embed iris information into face images. Finally, we show the advantages of the proposed watermarking scheme by computing the ROC curves and make some comparisons recognition rates of watermarked face images with those of original ones. From various experiments, we found that our proposed scheme could be used for establishing efficient and secure multi-modal biometric systems.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1564-1569
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• 2009

Project managers play a key role in cost, time, and quality of a project. Selection of an appropriate project manager, therefore, is considered as one of the most important decisions in any construction project. It should be noted that most important decision makings are carried out by the project manager throughout the project. Traditionally, project manager selection in construction companies in Iran is through organizing an interview with candidates and selecting the most appropriate choice in accordance with the capabilities, potentials and individual specifications coupled with the requirements of the project. In the same direction, organizing interview on selection of appropriate candidate is usually carried out by senior managers of companies. Determination of the most important criteria for selection of project managers and also identification of significance coefficient of each criterion can highly help senior managers of companies to make sound selection decisions. In this paper, a numerical model has been considered for determination of significance of each criterion, details of which are submitted for selection of project manager in Iranian petrochemical, oil and gas sector companies. For this reason, all criteria- considered by senior managers of the companies under study- are first determined. Then, information obtained through 38 interviews, conducted by senior managers of the mentioned companies while selecting project manager, is analyzed. Significant coefficient of each criterion is calculated through the accumulated data using fuzzy curves method.

• Fibers and Polymers
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• 제6권4호
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• pp.348-354
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• 2005

These days consumers' various demands are accelerating research on apparel manufacturing system including automatic measurement, pattern generation, and clothing simulation. Accordingly, methods of reconstructing human body from point-clouds measured using a three dimensional scanning device are required for apparel CAD system to support these functions. In particular, we present in this study a human body reconstruction method focused on two issues, which are the decision of the number of control point for each sectional curve with error bound and the local knot removal for reducing the unusual concentration of control points. The approximation of sectional curves with error bounds as an approximation criterion leads all sectional curves to their own particular shapes apart from the number of control points. In addition, the application of the local knot removal to construction of human body sectional curves reduces the unusual concentration of control points effectively. The results may be used to produce an apparel CAD system as an automatic pattern generation system and a clothing simulation system through the low level control of NUBS or NURBS.

• 전력전자학회논문지
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• 제5권4호
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• pp.343-351
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• 2000

본 논문에서는 정렬과 비정렬된 회전자 위치들에서 자화곡선들을 기본으로 한 SRM의 회전자 워치펑가 알고리즘을 제안한다. 자화곡선은 측정된 상 전압과 상 전류로부터 계산되어지고, 계산된 데이타는 회전자 위치검출을 위한 자화곡선의 입력으로 사용되어진다. 자화곡선은 비션형 특성해석에 적합한 퍼지 알고리즘으로 구생되어졌다. 종래의 지삭기반 퍼지제어기를 이용한 자속관측기가 SRM의 센서리스 제어를 얻기 위해 제시되었다. 최적 각을 선정하기 위한 방식이 회전자 위치검출을 위해 제시되었다. 제안된 알고리즘의 강인성이 시뮬레이션과 실험결과의 비교를 통해 입증되었다.