• International journal of advanced smart convergence
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• v.1 no.1
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• pp.57-60
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• 2012

In this paper, we have performed a safety analysis on an automotive evaporator inspection system. We performed the bi-directional analysis on the manufacturing line. Software Fault Tree Analysis (SFTA) as backward analysis and Software Failure Modes, Effects, & Criticality Analysis (SFMECA) as forward analysis are performed alternately to detect potential cause-to-effect relations. The analysis results indicate the possibility of searching and summarizing fault patterns for future reusability.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.20
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• pp.1-24
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• 1989

This paper takes aim at the reliability evaluation by application of Fault Tree Analysis and its computerization. FTA is one of the methods for evaluation of system reliability and safety analysis. The important characteristic of this paper is that computer program is written in the package program(dBaseIII+) by 16Bit/AT personal computer. The program consists of three program segments. (1) The minimal cut sets of the system fault tree are obtained by means of "Fault tree reduction algorithm" (2) The minimal path sets are obtained by inversion of the minimal cut sets determined from fault tree (3) The importance of the basic events which are presented in the minimal cut sets is obtained by means of structural importance analysis. In this paper, a Fault Tree Analysis is applied to a BAG FILTER which is a kind of dust collector.collector.

• Journal of the Korea Safety Management & Science
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• v.2 no.3
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• pp.13-25
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• 2000

This paper reviews and classify fault-tree analysis methods developed since 1960 for system safety and reliability. Fault-tree analysis is a useful analytic tool for the reliability and safety of complex systems. The literature on fault-tree analysis is, for the most part, scattered through conference proceedings and company reports. This paper classify the literature according to system definition, fault-tree construction, qualitative evaluation, quantitative evaluation, and available computer codes for fault-tree analysis.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.533-542
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• 1994

This paper presents the new algorithm for fault analysis and this algorithm obtains requisite term for fault analysis by the two-port network technique. Therefore, the fault calculation time is composed of only few fundamental arithmetic calculation. The graphic user environment for fault analysis is implemented in mouse-oriented user interface with window and pull-down menu. The result of the algorithm proved to be identical with the sample system in Ref.[8]. this package can be a useful tool for fault analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.401-406
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• 2000

Fault tree analysis (FTA) is a widely used methodology for reliability analysis. The method is useful in that it suggests a very comprehensive way of describing the hierarchical relations of causes of faults and the corresponding results. However it is difficult to get appropriate fault trees for given products or systems without very profound knowledge and experience. This work aims to develop a methodology of fault tree construction using the results of function deployment for machine parts, which provides an objective way of preparing fault trees. The failure modes are defined to each function network generated by the function deployment method and the fault tree with respect to each viewpoint is constructed by arranging the failure modes. The fault tree is finally obtained by synthesizing the fault trees with respect to each viewpoint. The example of fault tree construction is also shown.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.361-363
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• 2003

To reduce the effect of fault on underground power cable, we need exact and fast fault location detection technique. In this thesis, we describe on filter design technique that can be applied to on-line fault defection technique. To design fitter for fault location defection on Power cable, we should analysis fault signal. So we designed test bed for fault generation and measured fault signals for analysis. Through the analysis of signals, we found that ANC filter can be applied to separate fault signals and we designed a ANC filter. We tested on the designed filter through computer simulation, and we describe its results in this paper.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.262-269
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• 1998

In case the fault occurs in AC power supply network, protective relaying system must selectively detect line-to-line/ground fault and immediately cut off the power flow into the fault location for guaranteeing the safety of people, electric vehicle and ground installation etc. It is the most important point in power system operation to minimize the fault duration by rapid trip scheme and accurate estimation of the fault location. In this paper, we analyze the load characteristics of each vehicle, perform the fault analysis of AC power supply network using AT current-ratio method. The result shows its usefulness.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.369-373
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• 2000

High impedance fault(HIF) is defined as a fault that the general overcurrent relay can not detect or interrupt. Especially when HIF occurs in residential areas, energized high voltage conductor results in fire hazard, equipment damage or personal threat. This paper proposes a fault location estimation algorithm for high impedance fault using wavelet transform. The algorithm is based on the wavelet analysis of the fault voltage and current signals. The performance of the proposed algorithm is tested on a typical 154kV korean transmission line system under various fault conditions. From the tests presented in this paper it can be concluded that a fault location estimation algorithm using wavelet transform can precisely calculate the fault point for HIF.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.533-539
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• 2018

In this paper, the transformer type superconducting fault current limiter (SFCL) with additionally coupled circuit was suggested and its peak fault current limiting characteristics due to the fault condition to affect the fault current were analyzed through the fault current limiting tests. The suggested transformer type SFCL is basically identical to the previous transformer type SFCL except for the additional coupled circuit. The additional coupled circuit, which consists of the magnetically coupled winding to the primary and the secondary windings together with another superconducting element and is connected in parallel with the secondary winding of the transformer type SFCL, is contributed to the peak fault current limiting operation for the larger transient fault current directly after the fault occurrence. To confirm the fault current limiting operation of the suggested SFCL, the fault current limiting tests of the suggested SFCL were performed and its effective peak fault current limiting characteristics were analyzed through the analysis on the electrical equivalent circuit.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.932-941
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• 2004

The objective of this study is to detect the multi-fault of HVAC system using a new pattern classification technique. To classify the effect of single-fault in determining the pattern, supply air temperature, OA-damper, supply fan, and air flowrate were chosen as experimental parameters. The combination of supply temperature, flow rate, supply fan and OA-damper were chosen as multi-fault conditions. Three kinds of patterns were introduced in the analysis of multi-fault problem. To solve multi-fault problem, the new pattern classification technique using residual ratio analysis was introduced to detect the multi-fault as well as single-fault. The residual ratio could diagnose single-fault or multi-fault into several patterns.