• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.4
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• pp.33-43
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• 2023

In this study, it was developed and verified an application method of fuzzy-logic theory to the rating process of agricultural fill dam safety. A fuzzy-logic is very famous logical system when some decision making is made on the status of a lack of information. Three proxies were selected and configured membership functions (MFs) and these MFs were activated in the process of fuzzification procedures. Fuzzified vlaues were passed through the rule-based inference system, then fire strength could classified among cases of the rule-based inference system. To obtain final results, Mandani-type was adapted in the defuzzification process. As the results, it was shown the developed system can give a correct results that was compared with Matlab - fuzzy inference function. More ever it could perform the detailed analysis and improvement on the infrastructure safety rating process using classical diagnosis method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1442-1449
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• 2016

This paper proposes a diagnosis to detecting poor contact fault and fault location. Electrical fire by poor contact fault of power cable occupied a large proportion in the total electrical installations. The proposed method has an object to prevent electrical fault in advance. But detecting poor contact fault is difficult to detect fault type and fault location by using conventional reflectometry due to faults generated intermittently and repeatedly on the time change. Therefore, in this paper poor contact fault and fault conditions were defined. System generating poor contact fault produced for the experimental setup. SSTDR and algorithm of reference signal elimination heighten performance detecting poor contact fault on live power cable. The diagnosis methods of signal process and analysis of reflected signal was proposed for detecting poor contact fault and fault location. The poor contact fault and location had been detected through proposed diagnosis methods. The fault location and error rate of detection were verified detecting accuracy by experiment results.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.28-33
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• 2015

Three phase heaters in 7 buildings of 2 sites were examined for precise diagnosis. The sample size was 626. Precise examinations of current and the heater wiring status revealed contact failures and arcs in equipments that had CUF larger than 10%. Contact failures and arcs may cause electrical fire. Therefore, the correlation between the CUF and the imperfections in heater equipment and its wiring was analyzed for three phase heaters. In addition, the protection devices used for detection of heater imperfections were found to be unsuitable for the purpose. Current status of the protection devices was analyzed, and suggestions for improvements were made for new standards of the protection device selection.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.41-46
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• 2011

The purpose of this paper is to analyze the causes of accidents related to the 3 phase 170 kV gas insulated switchgear of a power system collected from accident sites to secure data for the prevention of similar accidents and provide important points of view regarding diagnosis for the prevention of accidents involving gas insulated switchgears. The analysis results of the causes of accidents involving gas insulated switchgears showed deformation of the manipulation lever installed at the S-phase, disconnection of the insulation rod connection, melting of the upper conductor, a damaged tulip, damage to the lower spacer and the spacer at the breaker, etc. It is believed from this result that the potential for accidents has expanded due to accumulated energy as a result of repeated deterioration. The carbonization depth of a GIS was formed near the screw (T2, T3) used to secure the lower pole of the S-phase tulip. It is not known what has caused the screws to be extruded and melted. However, it is thought that an unbalanced electromagnetic force, micro-discharge, surface discharge, etc., have occurred at that point. In addition, even though 16 years have passed since its installation, there was no installation defect, act of arson, accidental fire, etc. General periodical inspection and diagnosis failed to find the factors causing the accidents. As a system contained in a closed metal container, it has a high risk factor. Therefore, it is necessary to design, install and operate a GIS in accordance with the standard operational procedure (SOP). In addition, it is necessary to apply conversion technology for periodical SF6 gas analysis and precision safety diagnosis. It is expected that tracking and managing these changes in characteristics by recording the results on the history card will provide a significant accident prevention effect.

• Research in Plant Disease
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• v.23 no.4
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• pp.306-313
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• 2017

Recently fire blight occurred in the Republic of Korea and eradication program for the disease has been executed since then. Specificity and detection sensitivity of the 2 antibody-based diagnostic strips to Korean isolates of Erwinia amylovora (Ea) and their application for on-site diagnosis were evaluated in this study. Ea AgriStrip, a commercial diagnostic kit, and EB strip, developed in this study, reacted positively to the all tested Korean Ea strains and also to most of Erwinia pyrifoliae (Ep) strains causing black shoot blight. They reacted negatively to all Pusedomonas syringae pv. syringae (Pss) strains that cause shoot blight on apple. Detection sensitivity was similar between the 2 strips. For on-site diagnosis, the two strips reacted positively only to the extractions of the fire-blighted samples on all fire blight occurred orchards except one orchard at which on-site diagnosis was carried out at winter time. In addition, they reacted positively to the black-shoot blighted extractions from the black shoot blight occurred apple orchard. These results suggest that both EB strip and Ea AgriStrip would be useful for on-site diagnosis of fire blight in Korea.

• Fire Science and Engineering
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• v.32 no.2
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• pp.73-81
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• 2018

The purpose of this study is to survey the learner's recognition about the descending life lines for the fire emergency escaping purpose (DLL-FEEP). For that, we surveyed 307 adult males and females in Chungcheongnam-do, Daejeon metropolitan city, and Sejong metropolitan autonomous city. The surveyed data was statistically analyzed by SPSS 20.0 win program. In the results, 72.64% research participates have received a fire safety education. However, among them, 39.46% research participates have received a fire safety education without the contents of the DLL-FEEP. The style of the education for the DLL-FEEP is mainly the instructor-led training which is 79.26%. The 81.43% research participates have never used a DLL-FEEP. Based on the results in this study, the political proposal based on these results was as follows. We think that the expansion of the educational contents for the DLL-FEEP need in the fire safety education. We believe that results of this paper will help to serve as a basis for the efficient fire safety education with adults.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.2
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• pp.56-67
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• 2018

In general, fire and evacuation simulators are used independently to diagnose the safety of building. Because this method does not reflect the movement of pedestrians considering fire spread, it is difficult to expect diagnosis of safety with high accuracy. In this study, we propose the simulation method that can describe the movement of pedestrians in the fire emergency. Our method reflects the FDS fire spread data into FFM and explains the situation in which a pedestrian recognize a fire and escapes to a safe route. This study consists of data linkage between FDS and FFM and development of improved FFM. Experiment of the proposed method is progressed using the EgresSIM. Simulation result shows that the number of evacuees on each exit is affected by the presence or absence of fire and it was confirmed that the evacuation time increase and the bottleneck phenomenon deepened by exit.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.409-412
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• 2011

최근, 전력설비의 열화진단 및 안전검사에 있어 편의성과 활용성의 측면에서 자외선 카메라가 많은 관심을 받고 있다. 자외선 카메라는 전력설비의 코로나 방전에 의한 자외선 검출을 응용한 기기로서 열화지점과 열화정도를 이미지 형태로 직관적으로 나타낼 수 있다. 따라서 전력설비의 정확한 열화진단을 위해서는 코로나 방전에 대한 전기적 특성과 자외선 특성에 대한 이해가 중요하다. 본 논문에서는 전력설비의 열화진단을 위한 코로나 방전을 모의하고, 그에 따른 자외선 이미지와 전기적 특성에 관해 연구하였다.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.170-176
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• 2018

Laboratory inspection and diagnosis is a means of investigating and assessing various hazards or the state of research equipment in a laboratory, then taking appropriate safety measures to prevent accidents and injury. In many cases, laboratory inspection and diagnosis carried out by agencies are performed in a perfunctory manner that only barely satisfies the legal requirements. The aim of the present study is to provide clearly established pricing criteria for laboratory inspection and diagnosis, so as to prevent recurrence of laboratory accidents and to establish a safe laboratory environment. In order to clarify previously unclear matters, such as the lower limit for bids submitted by laboratory inspection and diagnosis agencies, technical manpower requirements, and number of laboratories inspected and diagnosed per day, a questionnaire survey was administered to agency personnel. First, when asked what the lower limit for bids submitted by agencies should be in order to improve reliability of inspection and diagnosis results and make up for the shortcomings of the lowest-bidder-wins system, 85.5% of respondents answered that the lower limit for bids should stand at no lower than 90% of the estimated price. The level of technical expertise among the technical personnel committed to laboratory inspection and diagnosis was shown to impact the reliability of results, and questionnaire results indicated a need to vary technical expertise levels depending on the degree of hazard, substances handled, and equipment used in a given laboratory. Level of technical expertise(67.1%) and number of personnel(52.6%) were shown to have a greater impact on reliability of diagnosis than on reliability of inspection. According to the results, it is determined that three persons(specialist, advanced and intermediate) should be committed to inspections, while four persons(professional, specialist, advanced and intermediate) should be committed to diagnoses. The respondents indicated a larger number of laboratories could be inspected than diagnosed per day. This can be attributed to differences in the amount of work each task involves, and the time each task takes. Assuming a six-hour work day not counting transportation, paperwork and rest, it is thought that inspection of up to 36 laboratories will be possible if each laboratory is assigned no more than 10 minutes(34.7%), while up to 24 laboratories could be inspected and diagnosed if each laboratory is assigned 15 to 20 minutes(35.1%).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1669-1674
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• 2017

In this study, We have discussed the development of a diagnostic device to detect and prevent electrical fire due to the arc caused by contact failure and partial disconnection at the connection part of the three-phase electric heater wiring used in the industrial field. The arc caused by contact failure and partial disconnection at the connection part of the electric heater shows a change in the current effective value. Therefore, it is possible to determine whether there exists a defect by analyzing the current unbalance factor and the number of current fluctuations with the diagnostic apparatus. The three-phase unbalanced heater is considered to be capable of determining defects through periodic measurement and trend analysis of the current unbalance factor. It is also expected that this device can be used not only for electric heaters but also for detection of defects in wiring and connections of electrical equipment having a characteristic of constant load current.