• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.136-144
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• 2021

Railroad Systems, which are national infrastructure industries, cause unexpected property and human damage if they fail to function while operating. Accordingly, railroad facilities supporting the railroad system are areas where high reliability and safety are required. However, it is time for systematic and scientific maintenance to be taken away from the traditional maintenance methods, as the nation's railroad facilities are now aging seriously. The purpose of this study was to secure the safety and reliability of the aging railroad communication facilities and to improve their performance. The research subjects were selected as a precision diagnosis process for railroad communication facilities, and improvement points were derived through detailed precision diagnosis process analysis. It is deemed that this study can contribute based on securing stability, improving reliability, and continuous improvement of railroad communication facilities should be conducted in the operation of the entire railroad system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.395-396
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• 2012

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.246-253
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• 2010

National major facilities have been rigorously investigated using regular safety inspections and precision safety diagnosis since the Special Law for Facilities Safety Management was made in 1995. However, the process of safety inspection and precision safety diagnosis could be doubted due to intervention of facility owner for safety level evaluation, competition to obtain low price order, and low technical skills of inspection companies. Although the management processes for evaluating the inspection companies were used for several years, the process should continue to improve in the safety inspection field. This study analyzed the recent evaluation system and the ratios of insufficient inspection. Estimation of national loss expenses to the insufficient safety inspection was investigated to recognize the necessity for the improvement of facility inspection process and evaluation system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.639-642
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• 2000

Chemical facility system have dangerous elements that can injure the human like an explosion and a fire, gas poisoning by a leakage of the harmful chemical material. In addition to a vibration of the machine occurs the leakage. Therefore, the chemical factory requires for periodic monitoring of the vibration. But, until now, the operator has executed a monitoring of the machine by the senses. So, the diagnostic expert system by which the operator can judge easily and expertly a condition of the machine is developed. This paper describes the structure of diagnostic system and the diagnostic algorithm using fuzzy inference

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.449-459
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• 2021

More than 80 % of agricultural reservoirs are old facilities over 50 years old, and safety and function declines occur. As a result, safety accidents such as the collapse of the reservoir have occurred. Precise safety diagnosis is conducted in advance to prevent accidents such as reservoir collapse, and Water resources facility improvement project are implemented based on priority. However, the priority of the business is selected based on the subjective judgment of the facility manager. In this study, we set 80 hypotheses based on the results of precision safety diagnosis and decision-making examples of existing Water resources facility improvement project and selected 45 variables using correlation analysis and significance test. Using logistic regression analysis, the final 21 variables were selected and a decision support model was presented, and the classification accuracy of the model was 86.8 %. In this research, the part that presented the quantitative index for decision support when selecting the Water resources facility improvement project has important significance.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.4
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• pp.1-8
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• 2016

In 2008, 17, 596 dams and reservoirs are scattered across South Korea, and 17, 505 of them (99.5 %) are used for agriculture and 99.3 % are fill dam types. This study aimed to review literature related to the precise safety diagnosis system for agricultural reservoirs established by Korea Rural Community Corporation (KRCC) and analyze problems of its evaluation method. And then, it proposed ways to improve the system including a modified diagnosis system, which was applied to pilot districts in order to verify the utility. For assessment model development of agricultural reservoir, we reviewed status of precision safety inspections systems of agricultural reservoir. There are many problems such as assess agricultural reservoir not by sheet which used in fill dam but by block which used in concrete dam construction and diversion tunnel which main element in reservoir levee is treated as water intake facility. For considering diversion tunnel in reservoir levee, previous precision safety inspection systems which summed in separated phenomenon, separated element, separated site, separated facility was change to new systems which summed in site, phenomenon, element, and facility. Compared results of previous inspection system calculated total assessment index (Ec) with new system calculated total assessment index (Ec) are not show statistical difference.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.64-69
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• 2017

South Korea is the world's second-largest importer of LNG and possess about 70 tanks which are in operation by 2017. Thirty years as the design warranty period have exceeded since LNG storage tanks as the core facility of LNG industry were constructed in 1986. The LNG storage tank is under precision safety diagnosis from 2014 due to urban gas business act amendment. There is no criteria of condition evaluation for outer tank of LNG storage tank at the time of precision safety diagnosis. Through analysis of structural characteristic of LNG storage tank and civil structure condition evaluation standards, the criteria of condition evaluation for main members was developed. The criteria of objective condition evaluation can improve safety and reliability of LNG storage tank and suggest matenance criteria.

• Journal of Korean Association for Spatial Structures
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• v.21 no.3
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• pp.85-92
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• 2021

The purpose of this paper is to understand the key factors for efficient maintenance of rapidly aging facilities. Therefore, the safety inspection/diagnosis reports accumulated in the unstructured data were collected and preprocessed. Then, the analysis was performed using a text mining analysis method. The derived vulnerabilities of tunnel facilities can be used as elements of inspections that take into account the characteristics of individual facilities during regular inspections and daily inspections in the short term. In addition, if detailed specification information and other inspection results(safety, durability, and ease of use) are used for analysis, it provides a stepping stone for supporting preemptive maintenance decision-making in the long term.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.852-855
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• 1995

In modern plant lndustry, dignosis system is an essential implement because a human operator cannot check the state of system all the time. The recent facility needs a computer system which is able to replace and extense the function of the human expert. Checking the state of the plant system, the computer system uses signals form sensors attached to the plant systems. But, It is difficult to predict the cause of the failure from the sensing signals. Because the relationship among the signals cannot be easily represented by mathematical models. So expert system based on a fuzzy rule and Neural network method is sugguested. Expert system decide whether aa state of the system is ordinary of failure by the evaluation of the signals. If the state of the system is unstable, expert system preprocess the signals. When fault is occurred in the machine, the expert system dignoses the state of the system and find the cause as a primary tool. If the expert system dose not find the adequate cause successfully, neural network system uses the preprocessed signals as an input and propose a cause of the failure.

• Geophysics and Geophysical Exploration
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• v.16 no.4
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• pp.275-283
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• 2013

The sea dike is the most important facility of reclamation projects, and plays an important role in securing freshwater in the reservoir. Systematic research on practical approaches and data analysis techniques are lacking even though some geophysical methods such as electrical resistivity and self-potential surveys are included within the inspection processes. Hence, geophysical methods were considered for improvement of precision safety diagnosis methods after problems in the maintenance system have been identified, such as safety checks and precision safety diagnoses. In addition, geophysical methods customized according to variations in ambient environmental limiting factors such as pore pressure changes by tidal fluctuation, compaction characteristics of the fill materials, and the surface condition of the embankment were suggested.