• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.2
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• pp.94-98
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• 2011

Electrolytic power capacitors today form essential components for virtually any power electronic system such as DC/DC converter or UPS. Frequently, electrolytic capacitors for DC link voltage smoothing are the key components which determine the life cycle of the whole unit and often are responsible for converter breakdown failures. In this paper, ethernet-based remote diagnosis system for DC voltage smoothing capacitor using DSP control board is developed. To estimate the status of the capacitor, the equivalent series resistor(ESR) of the component has to be determined. The ESR detection scheme is based on the determination of the capacitor ripple power losses calculated from DC link voltage/current measurement. Experimental results show the veridity and reliability of the proposed ethernet-based remote on-line capacitor diagnosis system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.58-64
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• 2008

In this paper, we present an active anti-islanding method with a load monitoring system using reactive power control. The proposed method, which is based on reactive power control, has fewer harmonics components than those in conventional methods, and it can minimize the reactive power component of the grid because it compensates the reactive power component with the load monitoring. The proposed quick islanding detection method was confirmed from the experimental results with an inverter for a 3kW photovoltaic system.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.05a
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• pp.210-216
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• 1999

In this paper, we study the estimation of system reliability for the parallel system based on Spurrier and Weier [9] bivariate Weibul distribution. We assume that when one component fails, the workload of the remaining component becomes proportional to Øλ, where Ø〉λ 0. We obtain the maximum likelihood estimators for the parameters of system reliability, and by using the numerical method, study the effects of reliability for the Parallel system.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.2
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• pp.164-174
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• 1990

The improvement of linearized characteistics of induction motor control system with field oriented method is presented in this paper. A fully digitally controlled induction motor driver system based on the proposed linear control condition is described. The control system consists of IBM-PC/AT microcomputer, VSI PWM Inverter, and PI controller with softwave. By controlling the torque component, the rated flux component can be kept constant, even in the transient state. It is clearly confirmed by experiment that the improvement of the vector control condition is satisfactory. A simplified control model of an induction motor similar to the model for a separately excited DC motor drive system is obtained.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.44-54
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• 1992

In conventional fault-tree analysis, the failure probabilities of components of a system are treated as exact values in estimating the failure probability of the top event. For the plant layout and systems of the products, however, it is often difficult to evaluate the failure probabilities of components from past occurences, because the environments of the systems change. Furthermore, it might be necessary to consider possible failure of components of the systems even if they have never failed before. In the paper, instead of the probability of failure, we propose the possibility of failure, viz, a fuzzy set defined in probability space. Thus, in this paper based on a fuzzy fault-tree model, the maximum possibility of system failure is determined from the possibility of failure of each component within the system according to the extension principle.

• Spatial Information Research
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• v.7 no.2
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• pp.175-190
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• 1999

Recently , as GIS technology is rapidly improved and stabilized, there are some needs to reuse pre-developed and powerful GIS technology. GIS standardization based on components and open interfaces becomes a way to solve those reusability of previous GIS technology. This GIS standardization currently focuses on building the GIS Data Infrastructure that is being deployed globally. Especially, OpenGIS consortium which is mainly made up of international GIS leading vendors is announcing some GIS abstract specifications and implementation specifications. This study focuses on how could we design and implement the OLE/COM-based data provider component based on various DBMS or file systems, how could these data provider components be used for enterprise UIS(Urban Information Systems) and how could various formatted GIS data be shared in one system. Also some problems practically caused by an implementation process of data provider component are listed up and some solutions are given. Furthermore, design and analysis of UML(Unified Modeling Language) was reformed through the data provider component development task and this UML methodology is able to indicate a standardized model for newly developed data provider component.

• The Journal of Engineering Research
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• v.6 no.1
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• pp.111-124
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• 2004

The advanced semiconductor technology and electronic design automation(EDA) tools make it possible to implement the system on the programmable logic devices. The electronic design method is also changing from schematic capture to hardware description language. In this paper, I present the architecture of multi-dimensional digital filter which can be efficiently implemented on PLDs. This is based on the former research results which are called algorithm decomposition technique. Algorithm decomposition technique is used to obtain the computational primitive from the state space equations of the multi-dimensional digital filtering algorithm. The obtained computational primitive is designed with VHDL. This can be used to implement the filtering system as a component. The designed filtering system is implemented on the PLD. Therefore, the filter can be upgradable on system. It is greatly reduced the time-to-market time of the system that is based on the multi-dimensional filter.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.208-211
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• 2001

최근 병원에서의 전산화가 급속도로 이루어지고 있는 가운데 각종 병리 영상을 이용한 원격 병리 진단 시스템의 필요성이 높아지고 있다. 본 논문에서는 병리분석을 위해 병리 영상을 인터넷 환경에서 Component기반으로 진단 보조하는 원격병리진단 시스템을 구현하였다. 서버의 부하를 줄이기 위해서 병리 진단에 필요한 영상처리 영역은 Component 내에서 처리되도록 하였다. 서버에서는 database에 대한 접근과 처리된 영상의 전송/채팅을 담당하도록 하였다. 원거리에 있는 병리학자들이 병리 세포조직 영상으로 상호 의전교환 및 영상 송수신, 영상처리를 통해 정확한 병리 진단을 할 수 있도록 도와주는 본 시스템은 시간과 공간의 한계를 극복하여 병리학자들의 진단 효율성을 높이게 될 것으로 기대한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.573-576
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• 2003

CBD(Component Based Development)란 재사용 가능한 소프트웨어 모듈 컴포넌트를 생성 ？ 조립생산, 선택. 평가 및 통합으로 구성하여 더 큰 컴포넌트를 생성하거나 완성된 어플리케이션 소프트웨어를 개발하는 기법이다. 본 논문에서는 대학의 학사관리시스템 구축시 업무간 재활용성 증대를 위해 컴포넌트 기반의 개발 방법을 적용하여 분석 및 설계를 하였으며, 체계구성 개념을 제시하고 주요 컴포넌트 모듈별로 수행 기능과 적용내역에 대한 명세를 하였다.

• Proceedings of the KIEE Conference
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• summer
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• pp.360-362
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• 2004

In this paper, as the preceding research for development of intelligent electronic device for digital based substation automation system, we tried to select the most suitable digital filter by comparison of frequency response characteristic, performance of wanted frequency component extraction.