• Journal of Platform Technology
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• v.6 no.3
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• pp.47-54
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• 2018

Predictive analysis in the hardware industry can be performed at an appropriate point in time to prevent failure of production facilities and reduce management costs. This helps to perform more efficient and scientific maintenance through automation of failure analysis. Among them, predictive management aims to prevent the occurrence of anomalous state by identifying and improving the abnormal state based on the gathering, analysis, and scientific data management of facilities using information technology and constructing prediction model do. In this study, we made a fault tree through the Relex tool and analyzed the error code of the hardware to study the safety.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.363.2-363
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• 2001

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.247-249
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• 2008

배전계통은 수용가에 전력을 공급하는 설비로서 계통의 안정적인 운영을 위하여 배전계통의 신뢰도를 산정하는 것은 중요한 의미를 갖는다. 본 논문에서는 배전계통을 구성하는 설비와 수용가의 전력 공급 유무에 따른 신뢰도를 산정하였다. Fault Tree Analysis(FTA)는 시스템의 고장을 해석하는 방법으로 사용된다. 시스템의 고장을 발생시키는 사건원인을 분석하여 Fault Tree(FT: 고장목)를 작성하고, 시스템을 구성하는 설비들의 고장확률 계산을 통하여 전 시스템의 신뢰성을 산정할 수 있다. 본 연구에서는 Relex 7.7 프로그램을 사용하여 FTA를 수행하였다.

• Journal of Advanced Navigation Technology
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• v.22 no.3
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• pp.179-188
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• 2018

In developing avionics systems, safety analysis and evaluation specified in SAE ARP4761 (Methods and Guidelines for Civil Aviation System and Equipment Safety Assessment Process) are carried out to prevent air accidents. Safety analysis requires knowledge of the abnormal state of the system, not its normal state, and its interrelationships with other standards. Therefore, a tool that automatically outputs data which proves compliance with safety certification standards is required. In this study,In this study, Schematized the safety analysis procedure of the specification and studied the method of applying the safety analysis CAD tools to individual procedure. As an example study, ARP4761 analysis was performed on the wheel brake system (WBS) of the ARP4761 appendix.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.10 no.1
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• pp.91-121
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• 1997

These days many p대ple are disterbed from eyestrain and the number is on the increase. So, through the oriental and occidental books I studied pysical and breathing exercises to help overcome eyestrain. The result were as follows; 1. The most common way is to close your eyes and rub them with warm palms. Then press or rub your eyeballs simultaneously. 2. There are two ways to exercise the eyeball by itself. One way is by looking at only one spot and the other way is to look four ways-first up, down, left and right-and then rotate right and left. 3. There are many different opinions that of the degree of strenth to be used in pressing the eyeball. I came to the conclusion that if we want to relex the eyeball, you must press it gently but to strenthen it, you must press it hard. 4. This method is a common way to press orbit or acupuncture points of the peripheral eyeball. For example B-1(晴明), S-2(四白), B-2(찬죽), Tae-Yang(太陽), TE-23(絲竹空), etc. 5. Since eyestrain is related to the whole body, it is known that you can relex your whole body by pressing the acupuncture points located in the head and posteriores cerviicis or by stretching the upper half of the body. 6. The best time to pratice is early in the morning or when you feel eyestrain. But I couldn't find a consistent on breathing method or the amount of time to practice.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.115-120
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• 2012

In order to establish preventive maintenance standards through analysis & reliability prediction of about 60,000pcs of 20kindsof relays and contractors used for Seoul subway trains, several life prediction methodologies were applied. Firstly, Occurrence, Severity, Detection were defined and predicted by applying operation characteristic of EMU to the number of actions of relays & contactors which the manufacturers generally offer as the life cycle data. Secondly, failure distribution and average life of parts were analyzed through interpretation of field data based on a lot of experience which had built up in the field for a long time. Finally, using the 217PLUS standard as a reliability prediction program, comparative analysis of use reliability and inherent reliability was done through reliability prediction at the part level and system level.

• Journal of Advanced Navigation Technology
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• v.13 no.1
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• pp.19-26
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• 2009

Air Traffic Management (ATM) system requires extremely high reliability for the safe and dependable operations in the airport. This paper reports a study on the reliability of the prototype ATM hardware system including the servers and local area networks. Reliability Block Diagram and Fault Tree Analysis on the prototype ATM hardware were performed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6A
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• pp.1067-1077
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• 2001

본 논문에서는 결함의 영향을 받지 않고 동작할 수 있는 AVTMR(All Voting Triple Modular Redundancy) 시스템과 듀얼 듀플렉스(Dual-duplex) 시스템을 설계하고, 각 시스템의 평가를 통하여 RAMS(Reliability, Avaliability, Maintainability, Safety)를 비교하였다. ABTMR 시스템은 3중화된 보터(voter)를 사용하여 설계를 하였으며, 듀얼 듀플렉스 시스템은 비교기(comparator)를 이용하여 시스템을 설계하였다. 각 시스템은 버스 레벨로 데이터를 비교하도록 설계하였으며, 시스템 평가를 위해서 소자의 고장율은 MILSPEC-217F에 기반을 두고 RELEX6.0을 이용하였고, 마코브 모델(Markov model)을 이용하여 시스템의 RAMS를 평가하였다. 본 논문에서는 각 시스템을 MC68000을 기반으로 설계하여, 각각 시스템에 사용되는 비용 및 시스템이 어느 부분에서 선호될 수 있는가를 RAMS 및 MTTF(Mean Time To Failure)를 통하여 선택할 수 있는 기반을 제시하도록 나타내고 있다. 이러한 AVTMR이나 듀얼 듀플렉스 시스템(dual-duplex system)은 결함 허용 시스템(fault tolerant system)으로 인간의 생명과 직접적인 관련이 있는 고속철도 시스템이나 항공기 시스템에 적용될 수 있다.

• IE interfaces
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• v.23 no.1
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• pp.68-77
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• 2010

Digital reactor protection system which consists of many identical modules, is fault- tolerant to provide high safety. The modules themselves including DSP(digital signal processing) card are also fault-tolerant in nature. This paper assesses the safety for being-designed digital reactor protection system of 2-out-of-4 G structure with lockout. Some interesting design alternatives are compared. Fault tree analysis for assessing system safety is performed by Relex software. The selected reactor protection system fully satisfies EPRIURD stipulation of mean failure time of 50 years.

• Journal of the military operations research society of Korea
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• v.33 no.1
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• pp.19-29
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• 2007

This study deals with developing and operating Reliability Analysis & Evaluation System for aircraft parts by analyzing ROKAF's AMMIS and phase inspection data for optimal inspection frequency. We suggest operating model with improving and adjusting inspection cycle by analyzing failure time data and tendency of crack with RELEX and Minitab software.