• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.56-59
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• 2001

In this paper, we explained the prevention activity for the fault of transmission facilities, And also considered the methods to lessen faults through the analysis of faults to be occurred in the west and south of chung-nam province (Cheong-yang power transmission branch office) for several years recently, and then proposed a suitable countermeasure and direction for the fault prevention activity.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.107-110
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• 2015

항공, 국방, 자동차, 철도, 조선, 원자력, 플랜트 분야에서 임베디드 시스템의 활용도가 높아지고 있다. 특히 항공 임베디드 시스템은 다른 분야에 비해 고신뢰성과 고성능이 동시에 요구된다. 안전필수 인증절차를 준수하면 설계 및 개발 단계에서 발생할 수 있는 다양한 결함을 예방 할 수 있다. 그러나 soft error와 같은 예측 불가능한 transient 결함을 대처하기 어렵다. 이러한 문제를 해결하기 위하여 고장감내 방법론과 검증방법에 대한 연구가 수행되어야 한다. 본 논문은 고장감내 기법 검증 방법론에 하나인 결함주입 기법을 제안한다. 본 논문에서 제안하는 결함주입 기법은 1) 정량적 평가 가능, 2) 시스템을 대상으로 검증 가능 같은 장점이 있다.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.9
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• pp.807-810
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• 2001

Election Weighting Machine is used an electronic scale which has many trouble because of broken load cells. In this paper, we propose an Intelligent Diagnosis System will for an electronic weighting machine using fuzzy logic. It s purpose be detect of the load cell s trouble. The electronic circuit of system, which call junction box , will be connected resistance in a series at circuit of Wheatstone Bridge for monitoring the condition of load cells.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.485-487
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• 2003

본 논문은 기설 WSI제 CVT에 대해 전자 과도해석 프로그램((EMTP : Electromagnetic Transient Program)을 통한 모의실험으로 철공진현상 제동저항 크기($0.5{\Omega}$)를 선정하고, 기설 154kV 및 345kV CVT의 철공진방지회로를 제동저항 단독취부 형태에서 과포화리액터와 제동저항을 직렬회로로 구성하여 취부하는 방식으로 개선한 후 실증시험 및 현장적용 시험을 통해 CVT 쳔공진현상 제동여부 확인 및 외함온도 변화추이 비교하여 개선효과를 제시함으로써 WSI제 CVT 고장예방에 기어코자 한다.

• Annual Conference of KIPS
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• 2006.11a
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• pp.535-538
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• 2006

FMEA(Failure Mode & Effect Analysis)는 발생 가능한 잠재 고장의 형태와 그 영향을 평가하고 고장을 예방할 수 있도록 표를 이용하여 체계적으로 접근하는 방법이다. FMEA를 활용하여 전자 의료기기의 신뢰성을 평가할 수 있는 방안에 대한 연구를 통해 의료기기의 신뢰성 향상을 위한 체계적인 접근이 요구된다. 본 연구에서는 소프트웨어의 신뢰성을 평가하기 위한 체계를 구축하기 위해 FMEA 기법을 근간으로 하여 전자 의료기기의 신뢰성 평가 체계 구축에 적용할 수 있는 방안을 수립하고자 한다.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2066-2068
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• 2005

We developed an on-line Ultra-high frequency partial discharge monitoring system to prevent a catastrophic failure of gas- insulated switchgears. The system has been tested in the laboratory for detection of various UHF PD signals. We also performed detection sensitivity verification tests and compared them with conventional IEC60270 method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.47-54
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• 1998

As higher reliability on generator facilities is required to early detect incipient faults, a diagnostic system for predictive maintenance of the facility is highly recommended. In this paper, an expert system is developed suing the CLIPS - expert system tool - utilizing the knowledge on the insulation diagnosis and the vibration diagnosis on the rotating machines. This expert system, with user - friendly interface for operator, is easy to revise and add diagnostic rules and knowledge.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2054-2055
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• 2007

이 논문에서는 철도전력시스템에서의 유지보수를 위한 고장률 분석에 관하여 설명하고 있다. 유지보수와 관련된 문제들은 시스템의 다른 부분과도 연관이 있어 기계적 사고의 위험성을 증가시킨다. 그러므로 설비는 교체와 예방정비를 겪게 된다. 여기서는 유지보수의 방법을 욕조곡선을 기반으로 정할 것이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.441-448
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• 2022

In the distribution system, there are multiple power protection systems such as circuit breakers at substations, and reclosers, minimum circuit ampacities, fault interrupters on distribution lines. They are widely used to prevent partial outages, cascading power failure or blackout so that other healthy systems could maintain the integrity in case of the instant fault or permanent failure on the power lines. However, when a fault happens, it could cause a major black out due to the lack of the protection cooperation between the protection relay of the circuit breaker at a substation and a protection system on the distribution lines. To achieve the power system integrity better, it is required to develop the circuit breaker which can be operational within 1 cycle(16ms). In this study, the high speed circuit breaker which is filled up with eco-friendly gas is developed. This equipment achieved an excellent test results based on IEC 62271-111 standard. It is respected that this equipment would contribute to prevent the wide area blackout by isolating a fault area quicker and faster.

• KNOM Review
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• v.24 no.1
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• pp.1-12
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• 2021

VM (Virtual Machine) live migration is a server virtualization technique for deploying a running VM to another server node while minimizing downtime of a service the VM provides. Currently, in cloud data centers, VM live migration is widely used to apply load balancing on CPU workload and network traffic, to reduce electricity consumption by consolidating active VMs into specific location groups of servers, and to provide uninterrupted service during the maintenance of hardware and software update on servers. It is critical to use VMlive migration as a prevention or mitigation measure for possible failure when its indications are detected or predicted. In this paper, we propose two VNF live migration methods; one for predictive load balancing and the other for a proactive measure in failure. Both need machine learning models that learn periodic monitoring data of resource usage and logs from servers and VMs/VNFs. We apply the second method to a vEPC (Virtual Evolved Pakcet Core) failure scenario to provide a detailed case study.