• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.213-221
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• 2024

Purpose: The purpose is to find the optimal way to quickly block the leak in the event of a leak accident in a tank lorry transporting hydrochloric acid aqueous solution, a hazardous chemical, and to carry out effective disaster prevention work to minimize damage caused by the leak. Method: We organized the overall characteristics of hydrochloric acid and accidents that occurred during transportation by accident type and cause, and created a small tank that can be tested assuming a leak situation in a hydrochloric acid tanker, creating an environment similar to the leak situation, and leaking in various ways. I would like to experiment and organize blocking methods. Result: Through experiments, an effective leak blocking method was confirmed. We would like to summarize measures to quickly block a leak in the event of a leak and present the optimal disaster prevention plan that can be applied at the accident site. Conclusion: It has been confirmed that using a combination of adhesive tape and magnets is more effective in blocking leaks. Rapid response is possible by repeatedly training business emergency response teams and product transporters to appropriately select and respond to leak-blocking equipment. Additional research on various leak prevention methods is needed in the future.

• Journal of Power System Engineering
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• v.11 no.3
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• pp.35-40
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• 2007

Leak would happen because of the damage of high temperature and high-pressure valve in nuclear power plant. condition based prevention maintenance is essential by using the suitable method based on local condition. Energy loss prevention can prevent from an accurate test, Local actually and ability. The methods of test for high energy fluid leak at present are analysis of ${\Delta}T$, AE(Acoustic Emission) analysis, and thermal image. The result for test of secondary system in nuclear power plant Unit reveals that the AE occurred clearly in leakage situation, but thermal image didn't occur. It is identified that leak is occurred when the orifice located front and back of valve operates. It shows that making a impatient judgment by using the single method if it is leakage is containing uncertainty. So we think that using the Multi-Measuring method is more sound judgment than single-measuring method.

• Journal of Power System Engineering
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• v.12 no.5
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• pp.65-70
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• 2008

The purpose of this study is to verify availability of the acoustic emission in-situ monitoring method to the internal leak and operating conditions of the turbine major valves relating to safety for turbine operating and prevention of turbine trouble at nuclear power plants. In this study, acoustic emission tests are performed when the pressurized electro-hydraulic control oil flowed through turbine electro-hydraulic controller oil check valve and turbine power/trip fluid solenoid valve in the condition of actual turbine operating. The acoustic emission method was applied to the valves at the site, and the background noise was measured far the abnormal plant condition. To judge for the leak existence ell the object valves, voltage analysis and frequency analysis of acoustic signal emitted from infernal leak in the valve operating condition are performed. It was conformed that acoustic emission method could monitor for valve internal leak to high sensitivity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.169-173
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• 1998

The practice of the construction and management of the underground petroleum storage facilities in Korea was investigated extensively, and the problems were identified. The advanced technologies in the U.S.A was comparatively studied. Considering the effectiveness of leak prevention and technology applicability, the following measures were suggested. To prevent corrosion of the tank, a clad tank, an interior-lining tank, or a double-wall tank was appropriate and appeared to be most cost effective. For piping, non-metalic material was suggested. To prevent spill, a catchment basin can be effective. For monitoring of leak, construction of more than one of one or combination of an automatic leak-detection device, a vapor-detection system, a ground water-monitoring system, and a double-wall detection system was recommended.

• Journal of The Korean Society of Clinical Toxicology
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• v.4 no.2
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• pp.122-127
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• 2006

Purpose: It is not easy to detect carbon monoxide (CO) leakage, and CO-intoxicated patients do not show a specific set of symptoms. The aims of this study are to clinically evaluate patients with CO gas intoxication from a CO leak at an underground shopping center, and to discuss the establishment of a disaster prevention plan. Methods: A total of 51 patients intoxicated by CO gas exposure in a gas disaster at a underground shopping center in Seoul on September 8, 2006 were enrolled in this study, and the patients' medical records were retrospectively reviewed. Results: The mean patient age was $29.4{\pm}6.3$. The initial mean COHb level was $14.98{\pm}6.97%$. The number of patients with COHb greater than 25% was three, and six patients experienced a syncopal attack. Only one patient-was treated with hyperbaric oxygen therapy. However, none of the patients complained of severe neurologic or cardiovascular symptoms. Conclusion: The symptoms of CO intoxication are non-specific and difficult to define, and the detection of CO leak-age is difficult. Thus, workplaces should be equipped with leakage sensors and automatic alarm systems and should have develop disaster prevention plans.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.425-430
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• 2008

To verify the system performance of portable AE leak diagnosis system which can measure with moving conditions, AE activities such as RMS voltage level, AE signal trend, leak rate degree according to AE database, FFT spectrum were measured during operation on total 11 valves of the secondary system in nuclear power plant. AE activities were recorded and analyzed from various operating conditions including different temperature, type of valve, pressure difference, valve size and fluid. The results of this field study are utilized to select the type of sensors, the frequency band for filtering and thereby to improve the signal-to-noise ratio for diagnosis for diagnosis or monitoring of valves in operation. As the final result of application study above, portable type leak diagnosis system by AE was developed. The outcome of the study can be definitely applied as a means of the diagnosis or monitoring system for energy saving and prevention of accident for power plant valve. The purpose of this study is to verify availability of the acoustic emission in-situ monitoring method to the internal leak and operating conditions of the major valves at nuclear power plants. In this study, acoustic emission tests are performed when the pressurized temperature water and steam flowed through glove valve(main steam dump valve) and check valve(main steam outlet pump check valve) on the normal size of 12 and 18 ". The valve internal leak monitoring system for practical field was designed. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. To improve the reliability, a judgment of leak on the system was used various factors which are AE parameters, trend analysis, frequency analysis, voltage analysis and amplitude analysis of acoustic signal emitted from the valve operating condition internal leak.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3383-3388
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• 2007

To compare the sensor performance of AE leak diagnosis system which can measure valve leak conditions, AE activities such as RMS voltage level, AE signal trend, leak rate degree according to AE database, FFT spectrum were measured on valve of the simulated test system for power plant. AE activities were recorded and analyzed from various operating conditions including different temperature, pressure difference, valve size and fluid using both piezoelectric acoustic emission sensor and Pb-Free acoustic emission sensor. The results of this study are utilized to select the type of sensors, the frequency band for filtering and thereby to improve the signal-to-noise ratio for diagnosis or monitoring of valves in operation. As the final result of application study above, portable type leak diagnosis system by AE was developed. The outcome of the study can be definitely applied as a means of the diagnosis or monitoring system for energy saving and prevention of accident for power plant valve.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.89-99
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• 2018

In the case of medium and small-sized businesses handling hazardous chemicals, emergency disaster prevention by workers, rather than a disaster prevention system using a safety device equipped with an automation system in case of a leak accident, is highly likely to occur. In order to solve these limitations, in this study investigated an emergency disaster prevention system that can be easily removed and adhered to the expected point of leakage according to the occurrence frequency of the leak during the chemical handling process.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.315-322
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• 2008

Valves in power plants are leaking internally by various damages including insertion of foreign objects on seat, seat crack, defects and fatigue crack of stem packing or welds etc. due to severe operating conditions such as high temperature and high pressure for extended period time. Acoustic emission(AE) technology should be applied in order to diagnose precisely and evaluate these valve internal leak. In this paper, results of studies which have accomplished in actual power plant are presented. We have analyzed background noise, AE signal level and frequency spectrum through laboratory tests on the basis of various actual conditions in power plant, and also have considered evaluation methods on the background noise, AE properties and the detectable minimum leak rate according to valve leak conditions through comparing with results of field tests in power plant. As a result of these studies, we conformed that evaluation of internal leak conditions including discrimination of leak or not, and the detectable minimum leak rate is possible, and also it is expected to contribute to safe operation and prevention of energy loss in power plants.

• Journal of IKEEE
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• v.26 no.2
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• pp.176-185
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• 2022

Data augmentation is general approach to solve overfitting of machine learning models by applying various data transformations and distortions to dataset. However, when data augmentation is applied in GAN-based model, which is deep learning image generation model, data transformation and distortion are reflected in the generated image, then the generated image quality decrease. To prevent this problem called augmentation leak, we propose a scheme that can prevent augmentation leak regardless of the type and number of augmentations. Specifically, we analyze the conditions of augmentation leak occurrence by type and implement auxiliary augmentation task classifier that can prevent augmentation leak. Through experiments, we show that the proposed technique prevents augmentation leak in the GAN model, and as a result improves the quality of the generated image. We also demonstrate the superiority of the proposed scheme through ablation study and comparison with other representative augmentation leak prevention technique.