• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.111-114
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• 2008

The paper considers the relation between on-line monitoring and diagnostics on the one hand and high-voltage (HV) withstand and partial discharge (PD) on-site testing on the other. HV testing supplies the basic data (fingerprints) for diagnostics. In case of warnings by on-line diagnostic systems, off-line withstand and PD testing delivers the best possible information about defects and enables the classification of the risk. Because alternating voltage (AC) is the most important test voltage, the AC generation on site is considered. Frequency tuned resonant (ACRF) test systems are best adapted to on-site conditions. They can be simply combined with PD measuring equipment. The available ACRF test systems and their application to electric power equipment -from cable systems to power transformers - is described.

• Transactions on Electrical and Electronic Materials
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• 제7권5호
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• pp.247-251
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• 2006

The traction DC feeder cable is one of the key devices for the safety operation of subway system, but for low voltage DC feeder cable (<3000 V) for subway, little attention has been paid by investigators on its online monitoring technology. With an introduction of cable laying and operation environment for the cable, this paper investigated the on-line monitoring technology of 1500 V DC feeder cable of subway. Firstly, in the text, the fault model of 1500 V DC cable was proposed based on the analysis of the fault type of the DC feeder cable, and then put forward synthetically on-line monitoring discharge signal and DC leakage current signal to assess DC feeder cable insulating state. The results of laboratory experiment prove that the proposed methods are feasible and can be implemented on-line monitor on DC feeder cable of subway.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기설비전문위원
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• pp.91-93
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• 2004

This study presents recent trends on the on-line monitoring and diagnostic systems for oil-immersed transformers. Specially, our system on Yeo Su thermal power plant is introduced for high sensitivity and accuracy of ours. It is combined with communication networks to provide an on-line remote monitoring system. Several alarm criteria are formulated to enable a superimposed monitoring system to perform decisive action. The reasons for monitoring the condition and maintaining the health of electrical apparatus were discussed. The experience at the fields and the criteria for the judgment are also discussed in detail.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권1호
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• pp.45-50
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• 1999

This paper describes a partial discharge (PD) on-line monitoring system used for large turbine generators. The system consists of a broadband current transducer, a computer-aid PD measurement system. By using a programmable fabricate band pass filter and an adaptive digital filter, the system can suppress the noise and extract PD signal from the intense noise surroundings successfully. Two simulated PD sources, which often exist in the large generators, were simulated and detected. At the end of this paper, some field test results, obtained from a 200MW generating set, were presented and discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.607-614
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• 2000

A cost-effective automated slope monitoring system is developed to monitor hazardous cut slopes along highways. This automated slope monitoring system consists of data-collection and visual monitoring, data-transmitting, database and internet service, and alarm system. Wire-line extensometer, automatic raingauge, and CCD camera are selected as monitoring instruments in this system, after consideration of failure characteristics of roadside cut slopes in the country. This paper describes the important features of this newly developed automated slope monitoring system.

• KSBB Journal
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• 제13권3호
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• pp.244-250
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• 1998

글루코스와 초산을 온라인 모니터링 하기위한 흐름주입분석기 술이 개발되었고 대장균발효공정에 이용되었다. 또한, Epoxy 고 분자 담체에 고정화된 GOD와 SOD 를 이용한 GOD-FIA와 SOD-FlA의 특성을 연구했다. 즉, FIA 의 조작온도, 운반용액 속의 첨 가제 (Triton, EDTA, natrium azid 등), 분석 시 료에 용 해된 신진대사물의 농도, pH, 초산측정시 사코진 농도 등에 따 라 고정화된 GOD와 SOD의 활성도, 즉 검출신호의 높이변화를 고찰했다. 최소배양액 과 복합배양액을 사용한 대장균 발효공정 에서 달루코스와 초산을 동시에 온라인 모니터링 하였으며 그결 과는 오프라인 분석결과와 잘 일치 하였다,

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1734-1736
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• 1998

On-line partial discharge monitoring system for generator stator insulation is developed. This system consists of remote and host units. The remote unit detects partial discharge signals from SSC(Stator Slot Coupler) installed between wedge and stator windings. The host unit monitors the condition of winding insulation. This system will be used as a module of a generator on-line monitoring system utilizing global network.

• Tribology and Lubricants
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• 제36권6호
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• pp.297-306
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• 2020

This paper reviews studies on the types and functions of oil sensors used for machine condition monitoring. Machine condition monitoring is essential for maintaining the reliability of machines and can help avoid catastrophic failures while ensuring the safety and longevity of operation. Machine condition monitoring involves several components, such as compliance monitoring, structural monitoring, thermography, non-destructive testing, and noise and vibration monitoring. Real-time monitoring with oil analysis is also utilized in various industries, such as manufacturing, aerospace, and power plants. The three main methods of oil analysis are off-line, in-line, and on-line techniques. The on-line method is the most popular among these three because it reduces human error during oil sampling, prevents incipient machine failure, reduces the total maintenance cost, and does not need complicated setup or skilled analysts. This method has two advantages over the other two monitoring methods. First, fault conditions can be noticed at the early stages via detection of wear particles using wear particle sensors; therefore, it provides early warning in the failure process. Second, it is convenient and effective for diagnosing data regardless of the measurement time. Real-time condition monitoring with oil analysis uses various oil sensors to diagnose the machine and oil statuses; further, integrated oil sensors can be used to measure several properties simultaneously.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.228-232
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• 1993

This paper describes a on-line monitoring and fault diagnosis system designed for the automation of a medium-size concrete plant. The system is based on the structure of a hardware system of data acquisition and a personal computer. Simulation results are presented to illustrate the system operation. It applies the preconstructed rules to the plant data for the diagnosis of weighing processes.

• 대한기계학회논문집A
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• 제24권12호
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• pp.2891-2898
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• 2000

The objective of this paper is to develop a fiber-optic acoustic emission(AE) sensor applicable to on-line monitoring systems which is suitable for long-distance signal transmission. An AE sensor was developed by use of a fiber-optic cantilever and an extrinsic Fabry-Perot interferometer(EEPI). The efficiency of signal processing was improved by driving the high frequency AE signals into the low frequency ones. In order to verify the developed sensor, the tensile and the pencil lead fracture(PLF) tests were performed including the experiment showing the Kaiser effect. Form tests, AE signals were successfully detected in the elastic-plastic deformation range, especially higher signals at the crack propagation. The developed sensor was expected to be used for an on-line monitoring of crack propagation in mechanical system.