• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.145-150
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• 2017

In this study, among the various types of plant equipment, valves, which are susceptible to water hammer, were selected as the diagnosis target. In order to effectively measure the vibration, an accelerometer was adapted for use in this difficult environment. The results showed that the maximum peak-to-peak vibration displacement caused by the action of water hammer on the valve was 21.40 mm, which would affect the structural stability of the valve and pipe. Meanwhile, the measured data was applied to the HIL simulator to verify the reproduction of the vibration. In the future, field data will be applied to the HIL simulator for the purpose of assessing the fatigue, durability and expected residual life of the plant equipment.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1397-1404
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• 2014

Grab cranes are used for multi-purpose when the sand and soil are deposited into harbor wharf or the undersea construction is performed. Among the components of crane grab, the wire drum and disc brake pad are key expendables and have disadvantages that lot of heat is generated and very expensive when replacing them. In this study, the thermal image analysis for the disc brake, which works with wire drum of the crane is suggested. The suggested system performs the pad thermal diagnosis through the thermal image using the characteristics that the disc and pad surface temperatures are distributed abnormally before the brake failure and the disc pad damage. Therefore, the damage by the failure can be prevented by discovering the abnormality of the machine parts before failure and the life cycle of the pad and the cost can be extended and saved by operating the crane performing constant checkup for the overload.

• Journal of Korean Tunnelling and Underground Space Association
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• v.3 no.3
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• pp.31-43
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• 2001

In this study, we carried out investigation and analysis on damages in tunnels on order to provide the basic information for the safety assessment of tunnels and to minimize the potential damage of the same kind as investigated. The frequencies of occurrence in terms of 4 items, i.e., service life interval, type of the damage, cause of the damage, and geological condition, were examined and summarized based on 44 foreign and domestic cases of tunnel damages. Also, we carried out a survey research of which the content included 28 questions on the tunnel safety assessment. The answers collected from domestic experts in tunneling suggested that the most probable cause of the tunnel damages was cracking in tunnels at 42~58%. They also suggested that the poor constrution work strongly caused the damages. Therefore, to ensure tunnel safety, high quality of constrution should be maintained as examined. The types of damage and their extent of influence on the overall tunnel safety are of practical importance to be used in the artficial intelligent system for tunnel safety assessment.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.1-10
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• 2023

The nuclear power plant(NPP)'s Instrumentation and Control(I&C) system periodically conducts integrity checks for the maintenance of self-diagnostic function during normal operation. Additionally, it performs functionality and performance checks during planned preventive maintenance periods. However, there is a need for technological development to diagnose failures and prevent accidents in advance. In this paper, we studied methods for estimating the reliability function by utilizing environmental data and self-diagnostic data of the I&C equipment. To obtain failure data, we assumed probability distributions for component features of the I&C equipment and generated virtual failure data. Using this failure data, we estimated the reliability function using representative artificial intelligence(AI) models used in survival analysis(DeepSurve, DeepHit). And we also estimated the reliability function through the Cox regression model of the traditional semi-parametric method. We confirmed the feasibility through the residual lifetime calculations based on environmental and diagnostic data.

• Journal of the Korean Institute of Gas
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• v.28 no.2
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• pp.93-104
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• 2024

Facility diagnosis is essential for the smooth operation and life extension of rotating equipment used in industrial sites. Compared to other diagnostic methods, vibration diagnosis can find most of the initial defects, such as unbalance, alignment failure, bearing defects and resonance, compared to other diagnostic methods. Therefore, vibration analysis is the most commonly used facility diagnosis method in industrial sites, and is usefully used as a predictive preservation (PdM) technology to manage the condition of the facility. However, since the vibration diagnosis method is performed based on experience based on the standard, it is carried out by experts. Therefore, it is intended to contribute to the reliability of the facility by establishing a system that anyone can easily judge defects by establishing a vibration diagnosis method performed based on experience as a knowledgeable code system. An algorithm was developed based on the ISO-20816 standard for vibration measurement, and the reliability was verified by comparing the results of vibration measurement at various demonstration sites such as petrochemical plant compressors, hydrogen charging stations, and industrial machinery with the results of analysis using a development system. The developed algorithm can contribute to predictive maintenance (PdM) technology that anyone can diagnose the condition of the rotating machine at industrial sites and identify defects early to replace parts at the exact time of replacement. Furthermore, it is expected that it will contribute to reducing maintenance costs and downtime due to the failure of rotating machines when applied to various industrial sites such as oil refining facilities, transportation, production facilities, and aviation facilities.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.24 no.1
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• pp.17-25
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• 2024

Fabry disease (FD) is an X-linked lysosomal storage disorder. It is caused by mutations in the α-galactosidase A gene, which results in deficient or absent activity of α-galactosidase A (α-Gal A). This leads to a progressive accumulation of globotriaosylceramide (Gb3) in various tissues. Manifestations of Fabry disease include serious and progressive impairment of renal and cardiac function. In addition, patients experience pain, gastrointestinal disturbance, transient ischaemic attacks, and strokes. Additional effects on the skin, eyes, ears, lungs, and bones are often seen. Reduced life expectancy and deadly consequences are being caused by cardiac involvement. Chaperone therapy or enzyme replacement therapy (ERT) are two disease-specific treatments for FD. Thus, early detection of FD is critical for decreasing morbidity and mortality. Globotriaosysphingosine (lyso-Gb3) for identifying atypical FD variants and highly sensitive troponin T (hsTNT) for detecting cardiac involvement are both significant diagnostic indicators. This review aimed to offer a basic resource for the early diagnosis and update on the diagnosis of having FD. We will also provide a general diagnostic algorithm and information on ERT and its accompanying treatments.

• Journal of the Korean Data and Information Science Society
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• v.28 no.5
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• pp.1069-1076
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• 2017

Recently, with the development of advanced medical technology and the introduction of most advanced medical equipments, life expectancy increases accordingly. Many people want to live long-lived in health. Therefore, if it is possible to pre-diagnose the sub-health condition and formulate an appropriate treatment plan, we can prevent the disease and reduce social expenditure costs. In this study, we statistically analyzed the data in responding to each questionnaire for healthy biorhythm and sub-health among targeted members of a specific group. The analysis for the effects of healthy biorhythm to male and female showed that there was a significant difference between male and female. In the analysis of the effects of the conditions of healthy biorhythm to the 10 sub-health indicators, the significant effects of good and bad condition has been observed. The results of the decision tree analysis showed that all the respondents with poor hormone and urological sub-health status have bad healthy biorhythms. In summary, in this paper we have shown that it may be possible to improve the sub-health condition and prevent disease in advance if the healthy biorhythm is well controlled.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.209-216
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• 2005

The objective of this paper is to investigate the H & Channel type lining board's capacity by using the fatigue test. The accumulated test result will be used to analyze the relation between the cause of crack occurrence and the behavior of structure. H type lining boards was comfortable behaved in over one million recycled. loading test. In case of channel type lining board specimens occurred the fatigue fracture in about one hundred thousand recycled loading test, and then could not secured endurance life that used servicing load.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.2
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• pp.239-246
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• 2004

To improve the durability of concrete structure, we usually consider the reduction of water-cement ratio, the increase of concrete cover depth and the use of mineral admixtures. The use of admixtures make concrete more durable and tighten against water in recent papers so it is needed to study more about the relationship between the admixtures and the chloride ion diffusion. Therefore we analyzed the correlation between chloride ion diffusion and physical properties such as compressive strength, void ratio, air permeability of the concrete, and tried to use them as fundamental data for analyzing chloride ion diffusion mechanism of the concrete mixed with mineral admixtures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.61-68
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• 2017

Bridge decks are members that rapidly deteriorated due to various environmental factors such as heavy vehicle and deicing salt, etc. As the lifespan of bridges built in Korea increases, it is expected that the demand for replacing the deteriorated bridge decks will increase. In other countries, Accelerated Bridge Construction technology using precast decks is already actively being used as a countermeasure for replacement demand of deteriorated bridge decks. In this study, bridge decks deterioration models are proposed by collecting and analysing the condition index data of domestic bridge decks. Also, the future replacement demands of deteriorated bridge decks in terms of replacement time and replacement scale are predicted.