• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.8
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• pp.1143-1148
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• 2013

This paper deals a watt-hour meter monitor system with applying a Power Line Communication (PLC) modem and a Data Concentrator Unit (DCU). PLC modem uses the power line, so there is no need to install dedicated wiring. This system makes it possible to monitor the amount of electricity of previous current month metering data, so it can easily apply a PC-management for the electric charges and maintenance with gathering the metering data.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.3
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• pp.3-7
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• 2010

As the distance between signal lines in memories of high density ICs like SoCs decreases rapidly, failure occurs more frequently and effective memory test techniques are needed. In this paper, a new SRAM structure is proposed to decrease test complexity and test time for embedded DRAMs. In the presented technique, because memory test can be handled as a single port testing and read-write operation is possible at dual port without high complexity, test time can be much reduced.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.638_639
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• 2009

The motors faults including mechanical rotor imbalances, broken rotor bar, bearing failure and eccentricities problems are reflected in electric, electromagnetic and mechanical quantities. This paper presents a study and the practical implementation of an induction motor for reactor containment fan cooler in nuclear power plant with Electric Signature Analysis(ESA). The results obtained present a good degree of reliability hence; the ESA predictive maintenance tools enable a pro-active evaluation of induction motors performance prior to failure.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1782_1783
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• 2009

Reflectometry that has been used to localize faults on a cable is introduced. One of the key point of reflectometry is finding time delay between the incident and reflected signals. In this paper, we propose new reflectometry that use Gaussian enveloped linear chirp signal, and use Kalman filter to estimate frequency rate parameter of the chirp signal. From the estimated frequency rate parameter, we can measure the time delay. In a simulation assuming open ended cable, the proposed method is proved to give a good estimation results.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.362-368
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• 2009

Electrical fires have been occurred continuously in spite of installing ELB. Therefore the concern with the electrical arc-fault that cause the fire has growing. This paper measured series arc fault currents by the method of arc generator test in UL standard 1699. The used analysis methods in this paper are three different ways using DWT(discrete wavelet transform) those are frequently used for the arc fault current signal analysis. The arc fault detection probability is 100 % by method using noise-energy/shoulder-duration ratio of approximation coefficient. As these results, the variation of noise-energy and shoulder-duration ratio of approximation coefficient are founded important factors for the analysis of arc fault.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.24-28
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• 2007

공장 내에서 부적절한 배선 및 설치 등에 의하여 검사과정을 수행할 경우 noise나 오결선을 유발시키며, 이는 측정해야할 신호가 부적절한 동작을 발생시키거나 검사가 되어 출하 후에 하지 않아도 될 A/S 지원을 해야 하는 등의 추가 경비가 소요되는 문제까지도 야기시킬 수 있다. 이때, 사용자측에서 발생될 불만에 따른 회사 및 제품의 신뢰도 저하는 더 큰 문제가 아닐 수 없다. 본 개발에서는 GUI(Graphic User Interface) 환경과 통신기술을 접목하여 다양한 제품의 검사를 위한 시스템을 개발하고자 한다.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1792-1797
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• 2007

This paper try to find root-cause of failure in a connector used in transmitting signals for throttle body control in automotives by analyzing possible failure causes and performing experiments to simulate the cable failure in field. The connector comprises fins, wires, and case moldings. The failure is due to degradation of initial clamping force required fixing fins and wires in the connector. Expansion and compression of the case molding material surrounding fins would cause the degradation. Investigations of strict initial claming force and control of thermal expansion property of the molding are required to prevent the failure.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.646-648
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• 1999

제어 시스템은 안전하고도 효율적으로 가동 시켜야 한다. 가동 효율을 향상시키기 위해서는 시스템의 이상 검출이나 감시를 행하여 고장의 조기 발견과 조기 복구를 하는 것이 중요하다. 따라서 제어 시스템을 평가하는데는 이상 검출이나 감시로 시스템의 정지를 사전에 방지하고 조기 복구를 가능하게 하는 일이 중요한 과제로 나타나고 있다. 본 논문에서는 PLC 제어 시스템을 적용하는데 있어서 PLC 외부에서 발생하는 이상 현상은 입력 신호의 이상, 출력의 이상 현상, 제어 동작의 이상 현상 등으로 분류 할 수 있으며 이러한 이상 현상을 PLC 프로그램으로 검출하는 방법을 적용코자 한다.

• KSCI Review
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• v.14 no.2
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• pp.117-122
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• 2006

In this paper, we designed and implemented the DCS(Distributed Control System) terminal remote monitoring board for build total unified management system based wireless communication on automatic control system fields. Also, it tested and evaluated for check an usability and performance. The board monitored relay and fuse status at power management room real-time. Therefore, we expected economic effects extend relay life-time that pre-detected errors and prevented relay fault.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1128-1133
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• 2006

The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the ]measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.