• Journal of the Korean Geotechnical Society
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• v.29 no.9
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• pp.71-80
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• 2013

This work studies the reliability analysis of a slope that considers multiple failure modes. The analysis consists of two parts. First, significant failure modes that contribute most to system reliability are determined. The so-called barrier method proposed by Der Kiureghian and Dakessian to identify significant failure modes successively is employed. Second, the failure probability for the slope is estimated on the basis of the identified significant failure modes and corresponding design points. For reliability problems entailing multiple design points, failure probability can be estimated by the multi-point first-order reliability method (FORM), Ditlevsen's bounds method, and Monte Carlo simulation. In this paper, a comparative study between these methods has been made through example problems. Analysis results showed that while a soil slope may have a large number of potential slip surfaces, its system failure probability is usually governed by a few significant slip surfaces. Therefore, the most important step in the system reliability analysis for a soil slope is to identify all the significant failure modes in an efficient way.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.79-90
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• 1999

In this paper, we suggested system reliability inequality used by failure rate distribution and developed new theorem-reliability function is increasing function. Also we calculated failure probability of coherent system used by variable transformation. Several examples are illustrated.

• International Journal of Reliability and Applications
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• v.9 no.2
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• pp.141-152
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• 2008

This paper presents equations, which can be used to evaluate the failure frequency and the failure rate of a two identical component parallel redundant system in which each component can operate in its wear out period, and the failure rate of each component is exponential power distribution. The optimum maintenance interval for a two identical component parallel redundant system can be obtained using these equations. The proposed approach is presented and illustrated using several numerical examples. The optimum maintenance interval for each component in a two identical parallel redundant system will depend on factors such as: failure rate, repair and maintenance times of each component in the parallel redundant systems.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.35-38
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• 1995

We proposed in this paper a systematic way for analyzing discrete event dynamic systems to classify faults and failures quantitatively and to find tolerable fault event sequences embedded in the system. An automated failure diagnosis scheme with respect to the nominal normal operating event sequences and the supervisory control problem for tolerable fault event sequences is presented. Moreover the supervisor failure diagnosis problem with respect to the tolerable fault event sequences is considered. Finally, a plasma etching system example is presented.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1989-1992
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• 2009

Maintenance is classified preventive maintenance before performing equipment failure and corrective maintenance after performing equipment failure. In preventive maintenance, we may analyze the failure data to end from beginning of equipment and allocate maintenance method and calculate maintenance cycle quantitatively by the failure data analysis. So, it has a merit to reduce system maintenance cost and to operate effectively but, it require high cost in system introducing and continuous operation to end of system. In corrective maintenance, we may calculate MTTR(mean time to repair) quantitatively based on function failure time. it can be based on establishing maintenance system for operation efficiency. In this paper, we may reflect the MTTR for the onboard equipped in Tilting train to establish maintenance system for Tilting train operation efficiency.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.11
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• pp.476-484
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• 2006

The failure prediction and preventive maintenance for the equipment of nuclear power plant area using reliability-centered maintenance have been grown. On the other hand, the maintenance for power distribution system consists of time-based maintenance mainly. In this paper, the new maintenance algorithms for power distribution system are developed considering reliability indices. First of all, Time-varying failure rates are extracted from data accumulated at KEPCO using exponential distribution function and weibull distribution function. Next, based on the extracted failure rate, reliability for real power distribution system is evaluated for applying the effective maintenance algorithm which is the analytic method deciding the maintenance point of time and searching the feeder affecting the specific customer. Also the algorithm deciding the maintenance priority order are presented based on sensitivity analysis and equipment investment plan are analyzed through the presented algorithm at real power distribution system.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.385-387
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• 2008

When a fault occurs in the distribution system, it is detected by protection system, then protection system is opened and de-energises the feeder where the fault exists. in this paper, the failure rate of protection system will estimate that using a discrete markov approach with failure data of protection system in order to improve the reliability of protection system.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.263-268
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• 2021

This paper statistically analyzes the time required for each failure cause and describes a diagnostic method for 159 reports of failure analysis of MV cables that occurred in the distribution system of KEPCO over the past 18 years. In addition, the manufacturer's failure rate compared to 100C-km was calculated using 381 cases of MV cable deterioration failure between 2008 and 2020. It is hoped that this paper will help those in charge of maintaining underground facilities at the business office to use the failure rate to prioritize facility diagnosis.

• 한국데이터정보과학회:학술대회논문집
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• 2006.11a
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• pp.97-112
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• 2006

FRACAS(Failure Reporting, Analysis and Corrective Action System) is intended to provide management visibility and control for reliability and maintainability improvement of hardware and associated software by timely and disciplined utilization of failure and maintenance data to generate and implement effective corrective actions to prevent failure recurrence and to simplify or reduce the maintenance tasks. This process applies to acquisition for the design, development, fabrication, test, and operation or military systems, equipment, and associated computer programs. This paper shows the FRACAS development process and developed FRACAS system for a defense equipment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.147-151
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• 1994

In this paper, we presents the prediction of failure point in facility by using the analysis of the failure symptoms. The status of a component is represented by the failure symptoms where as, the failure symptoms are expressed mathematically based on the Fuzzy Theory.