• Journal of the Korean Society for Nondestructive Testing
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• 제30권4호
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• pp.367-372
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• 2010

A power plant's heat exchangers work under poor conditions, such as high temperature, high pressure, corrosion, mechanical stress and vibration. Especially, partial joint-weld of heat exchanger's header to stub-tube is the place where incomplete penetration flaws can easily occur. But, it is hard to evaluate the safety of the structure by conventional nondestructive testing techniques. So it is necessary to test integrity of the weld inside and to develop testing technique and equipment that can detect the flaws at the weld point in order to enhance reliability of the test result. In this study, we developed a suitable automated ultrasonic testing system that can inspect the partial joint-weld of header to stub-tube of power plant. Finally, we showed the efficiency of the automated ultrasonic-testing-system from the application.

• Korean Journal of Community Nutrition
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• 제18권2호
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• pp.154-164
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• 2013

The objectives of this study were to assign reasonability to importance of weight selection issue in key performance indicator for performance evaluation of Centers for Child-care Foodservice Management (CCFSM) developed by using Balanced Scorecard (BSC), to draw key performance indicator (KPI) by perspective and to analyze differences in recognition on importance. From September 25 to October 9, 2012, we conducted a questionnaire-based study via e-mail, targeting chiefs and team leaders of nationwide 21 CCFSMs (43 persons), officials of local governments where CCFSM was established (21 persons), officials of Korea Food and Drug Administration (2 persons) and foodservice management experts (27 persons) in order to estimate the relative importance on 4 perspectives and 14 KPIs and analyzed its results by using 61 collected data. The results showed that relative importance of perspectives was estimated in order of importance as follows: business performance (0.3519), customer (0.3393), resource (0.1557), learning and growth (0.1531). Relative importance of KPIs was in order of importance as follows: Evaluation of sanitary management level in child-care foodservice facilities (0.1327), Level of customer recognition and behavior improvement (0.1153), performances of round visiting inspection on foodservice, sanitary, safety management, and foodservice consulting (0.0913). Our results showed that the recognition differences exist on the relative importance of perspectives and KPIs between officials of CCFSM, KFDA, local government and foodservice management experts. These observations will form the basis for developing evaluation systems, and it is considered that performance indicators developed on this basis will suggest direction of operation which CCFSM will have to perform.

• Journal of Sensor Science and Technology
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• 제9권1호
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• pp.44-50
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• 2000

Every object emits some energy from its surface. The emission energy forms surface heat distribution which we can capture by using an infrared thermal imager. The infrared thermal image may include valuable information regarding to the subsurface anomaly of the object. Since a thermal image reflects surface clutter and subsurface anomaly, we have difficulty in extracting the information on the subsurface anomaly only with thermal images taken under a wavelength. Thus, we use visible wavelength images of the object surface to remove exterior clutter. We, therefore in this paper, visualize the infrared image for overlaying it with a visible wavelength image. First, we make an interpolated image from two ordinary images taken from both sides of an infrared sensor. Next, we overlay the intermediate image with an infrared image taken from the infrared camera. The technique suggested in this paper can be utilized for analyzing the infrared images on non-destructive inspection against disaster and for safety.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제39권4호
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• pp.306-313
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• 2011

The damage tolerance analysis is required to guarantee the structural safety and the reliability for aircraft components. The damage tolerance method, which evaluate the life considering the initial crack, considers a fatigue design model of the aircraft main structure. The fatigue crack growth life should be calculated in damage tolerance analysis and the inspection time to define the replacement cycle. In this paper, the damage tolerance analysis is performed for a turbine wheel which has complex geometry. The equation of the stress intensity factor for complex geometry is hard to know, so that they are usually processed by finite element analysis which takes long time. To solve this problem, the stress intensity factors at specified crack are obtained by the FEA and the crack growth life is evaluated using the surrogate model which is generated by the regression analysis of the FEA data. From the results, the efficiency of the crack growth life calculation and the damage tolerance analysis could be increased by taking the surrogate model.

• Korean Journal of Construction Engineering and Management
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• 제10권2호
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• pp.102-110
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• 2009

The cost for maintenance of bridge structures such as repair or reinforcement is increasing. In addition, the efforts for inspection of bridge structures is becoming more important since the proper repair or reinforcement should be performed to save the maintenance cost and ensure the safety for public infrastructure. Therefore, it is studied on this paper to estimate the repair or reinforcement cycles using probabilistic approach for the steel-box girders of bridge superstructure. In addition, a computer simulation program is uniquely developed based on probabilistic approach to calculate the cycles derived from the function of age of bridge and performance rating curve which were previously studied. In order to ensure the reliability of results and appropriateness of the model, statistical analyses were performed. Also, the results were compared and proved to be similar with ones from previous statistical data related to the repair or reinforcement cycles. The results from this study is expected to be useful for the determination of proper time to repair or reinforce the bridge structure and raise the safetyness of bridge structure in advance.

• Fire Science and Engineering
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• 제33권5호
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• pp.109-117
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• 2019

When those who have caused a fire have no ability to compensate fire victims, the victims tend to charge fire agencies for state compensation to receive damage relief. This study analyzed two state compensation cases related to fires. The findings suggest that if there is a causal relationship between fire damage and mistakes committed by fire officials that are associated with fire prevention or special fire inspections, courts usually decide that fire agencies should compensate fire victims. Despite the introduction of a new article in the Framework Act on Fire-Fighting Services on December 26, 2017, titled "Exemption from Responsibility for Fire-Fighting Activities", exemptions are only available if inevitability of the activity has been proven. However, unlike rescue or first aid activity, inevitability is difficult to prove when it comes to fire inspection activity. Therefore, it is expected that state compensation suits related to fires will not decrease.

• Fire Science and Engineering
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• 제34권4호
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• pp.125-134
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• 2020

This paper aimed to statistically analyze the impact of fire needs not considered in previous reports based on preventive and preparedness strategies of fire administration and fire budget.. The panel data came from 16 metropolitan councils from 2008 to 2018 and was statistically analyzed based on the preventive measures of the fire administration (agreement for building permission, specific target for fire-fighting, public use facilities, and special fire inspection [SFI]), preparedness of the fire administration (fire safety education [FSE]), response of the fire administration (mobilization for fire suppression [MFS] and mobilization for ambulance service [MAS]), and fire budget. In the results, SFI, FSE, and MFS had a significant negative influence on the fire budget. Meanwhile, MAS had a significant positive effect on the fire budget (p < 0.01). These results reflect public policy in Korea; there has been a paradigm shift in fire administration: from disaster acceptance (focusing on recovery) to disaster response (focusing on field response) to disaster preparedness (focusing on preparedness).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.85-92
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• 2008

Demolition work is a precedence activity that is performed earlier than other remodeling activities. And demolition work is one of the critical path activities. So, demolition work is needed for systematic plan and management. However, contractors of the remodeling project established a rough plan and did not consider recycling wastes, safety of workers and structural stable of building. To improve this problem, a eco-friend process model of remodeling project is needed to be established. The process model is composed of five phases; 1) survey and analysis of general condition of demolition work, 2) prepare documents of demolition work 3) establishing demolition work plan, 4) demolition and inspection, 5) post-demolition management. Especially, demolition documents are based on establishing WBS, selecting the equipment and method, waste management and structure reinforcement. A process model of eco-friend demolition work is developed by using IDEF0 method.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• 제6권2호
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• pp.28-33
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• 2010

As a part of license renewal for the continued operation of Wolsong unit 1, the periodic safety review report was submitted near the end of design lifetime, 2012, and now is under reviewing. Major components of primary system such as pressure tubes, feeder pipes and so on are being replaced and many components of secondary system are also being repaired. So the license renewal of Wolsong unit 1 is expected to be acquired without significant issues. But on the other hand, steam generators of Wolsong unit 1 had the good performance and therefore the replacement and repair for the steam generator are not needed. Recently it is reported that some cracks were detected in a few of european steam generator with Alloy 800 tubes and the cause of cracks was the outer diameter stress corrosion cracking(ODSCC) due to the concentration of chemical impurities on the outer surface of tube. Accordingly the overall review on this issue was performed. The long-term operation is likely to results to form the concentration mechanism for the tube corrosion as the sludge build-up in the secondary side of steam generator and the crack in the crevice between tube and tube-sheet and expansion transitions is apt to be occurred. In this paper, the history of steam generator inspection and operation of Wolsong unit 1 are reviewed and the reliability of steam generator tube is evaluated and the steam generator aging management program for Wolsong unit 1 is introduced.

• Journal of the East Asian Society of Dietary Life
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• 제27권4호
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• pp.459-472
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• 2017

This study provides preliminary data to help organize improvements in analyzing the importance and performance of sanitation management items and the management of foodservice facilities in Community Child Centers in Daegu and Gyeongbuk Area. Questionnaires were distributed to 173 participants in sanitation and safety education at the center from April~June 2013 and 121 questionnaires were used as analysis data to investigate the management of foodservice facility at Community Children Centers in Daegu Gyeongbuk area. Most of the Community Child Centers are privately owned, and 62.0% had 20 to 29 children. Only 6.6% and 50.4% of the centers had nutritionists or cooks, respectively, due to budget deficits, and the foodservices were run by employees holding other positions. An investigation of sanitation management found that 84.3% of employees had a regular health inspection with significant differences between Daegu and Gyeongbuk (p<0.05). Most of the sanitation education was necessary, and the contents of sanitation education were applied to the fields in 66.1% of facilities. The reasons why the contents of them were not used in the fields included, the shortage of facilities and devices at 20.7%, which was the most common explanation. The separation separated of contaminated and non-contaminated areas were observed in 45.5% of facilities (p<0.01), separated sinks for pre-processing and cooking were found in 50.4%, and a show significant higher rate was noted in Daegu than in Gyeongbuk (p<0.05). An interior wall and, floor tile installation were observed 43.8% of facilities and a significantly higher rate was noted in Daegu than in Gyeongbuk (p<0.05). 30.9% of centers in Daegu and 11.3% of centers in Gyeongbuk area were equipped with a hot holding table(p<0.05). Overall, there is a need for education of foodservice to managers because most facilities do not have dietitians. In addition, facilities and equipment should be supplied continuously to foodservice facilities in community child centers.