• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.25-31
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• 2008

Recently risk management based on a quantitative assessment is considered to improve the level of safety in Korea. This paper focuses on the procedure of the quantitative risk assessment for natural gas pipelines. For that purpose, the methods to estimate failure frequency based on failure causes from European Gas Pipeline Incident Data Group and BG Transco, to analyze consequence caused by fire, and to calculate individual risk and societal risk have been proposed systematically in this paper. Risk criteria of individual risk and societal risk have been proposed by considering the environment of pipeline route in Korea. The proposed procedure of quantitative risk assessment may be useful for risk management during the planning and building stages of a new pipeline, and modification of buried pipeline.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.177-194
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• 1997

This thesis, deduced from studying eastern and western medical records, deals with geriatric demedtia in modern society. The result were obtained as follows : 1. Dementia is a kind of chronic, progressive, degenerative disease. The chief expression and pathogenic change of the disease is organic: e.g., extensive change such as cerebrum - atrophy, and denaturalization result. in such a situation intellectual capacities and the ability to enjoy daily life deteriorate trenendously. 2. A basic internal cause of the disease is Defficiencies of the heart, liver and kidneys. An exterior cause is an Excessiveness of the 'Dam'(痰), 'Blood Stasis', 'Fung'(風) and 'Fire'. In a Western Medical view, the reason for dementia is due to the onset of Alzheimer's disease and Brain anemia resulting from Multi - infarction or some other reason. If the white - matter of the brain is injured, then dementia easily to results. 3. Disease symptoms result in troubles in intellectual functions : e.g., memory, orientation, intelligence, judgement, common sence and calculating abilities. 4. The proper therapeutic treatment depends on the causes. When the Deficiency is serious, Fortification (heart, liver. and kidney deficiency) is applied and Decrease is follow. When Excessiveness of wrong is serious, the Decrease is tried before the supplement measure is used depending on the deficiency, which generally is used together with 'Fortify Right - Decreace Wrong'. 5. If the disease wasn't caused by some mental reason, it's difficult to be cured of the disease. When the degree of the disease is light and it doesn't continue for a long time, the therapeutic treatment can block the disease's progress and improve the patient's symptoms.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.746-756
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• 2017

Marine accidents of fishing vessels occupied about 70.5% of the whole marine accidents in Korea from 1996 to 2015, this ratio was not much changed for a long time. A lot of efforts have been taken recently but marine accidents do not reduce. Therefore a fundamental counterplan to decrease accidents in fishing vessel is indispensable for reduction of whole marine accidents in Korea. Since the most frequent occurring accidents in fishing vessels were engine trouble and collision in statistics by KMST (1996~2015), the study focused on them. The cause of engine trouble were poor inspection and maintenance of the mechanical system. The greatest portion of marine accidents was collision, and the biggest cause of the collision was poor watch-keeping. The better watch-keeping will be the best way to reduce the accident. For this reason, it may be necessary for the navigator to make strict precaution on the other vessels under way systematically and keep the regulation for preventing collisions, and for an engineer on watch to make a check the mechanical system periodically for reduction the engine trouble. Instead of penalty, incentive about safe navigation will be helpful for reduce accident as if automobile insurance would do. In order to prevent engine trouble, the fisheries federation establish the repair center. Futhermore the development of autonomous navigation system is necessary to reduce the marine accident.

• Journal of Oriental Neuropsychiatry
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• v.21 no.2
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• pp.215-227
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• 2010

Objectives : Jeon-Jeung(癲證) is one of negative symptoms from schizophrenia in Western medecine, which causes flattening of affect, emotional bluntness, and avolition. Compared with positive symptoms of schizophrenia, there is no established treatments that have been proved to be effective for negative symptoms, and since negative symptoms are chronically processed, they finally lead to devastate the mental health. Since Jeon-Jeung(癲證) is usually in set in adolescent period and tends to become chronic through life time, it is important to start getting treatments in early stage by being distinguished from other diseases, such as anxiety disorder. A patient in this case was affective blunting, general weakness, and delusion when sixteen years old. However, he refused to get Western medicine treatment and wanted oriental medicine treatment. Methods : The patient in this case had been suffered from severe stress from his family since he was young and had kept having irregular and unhealthy eating habits. Therefore, he diagnosed stagnant qi transforming into fire(氣鬱化火), heart blood deficiency(心血虛), and spleen-stomach deficiency cold(脾胃虛寒) and since then he had received several treatments including herbal treatment, acupumcture treatment, supportive therapy, and family therapy. These treatments were successful and reduced the level of symptoms. After discharged from the hospital, he had continued receiving outpatient treatment with his family for 8 months and his progress had been still observed after the discharge. Results : The symptoms of patient had been almost reduced and eliminated after he received 29days of admission treatment and the patient got better and better and now lives a normal life 8 months outpatient treatment. Conclusions : This result suggests that our oriental medical treatments and family treatments was effective on schizophrenia.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.205-211
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• 2014

Focused on Mt. Bogdkhan nature reserve in Mongolia, this study was conducted as a fundamental research to discover a tendency and characteristics of forest damage and to draw up measures for proper plans of forest restoration through an analysis of year-to year change using satellite images. In specific, land cover mapping was conducted by using Landsat images from 1994 to 2011, and then year-to year change was analyzed to investigate the features of forest damage in Mt. Bogdkhan. The results showed that the whole area of a reservation in Mongolia in 2011 was about $416.89km^2$; among them, forest area was $167,87km^2$, accounting for about 40.3%, followed by bare patch and grassland area (58.6%) and urban dry area (1.1%). In particular, compared in 1994, the area of forest in 2011 has increased by $6.12km^2$; while bare patch and grassland area has decreased by $10.81km^2$. Primary causes of forest degradation occurred in Mt. Bogdkhan nature reserve included illegal logging for fuel, forest and grassland degradation caused by domestic animals grazing, man-made forest fire, and disaster caused by insect pest.

• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.10-17
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• 2021

This paper presents the robust design of each component used in the development of an induction bolt heating system for dismantling the high-temperature high-pressure casing heating bolts of turbines in power plants. The induction bolt heating system comprises seven assemblies, namely AC breaker, AC filter, inverter, transformer, work coil, cable, and CT/PT. For each of these assemblies, the various failure modes are identified by the failure mode and effects analysis (FMEA) method, and the causes and effects of these failure modes are presented. In addition, the risk priority numbers are deduced for the individual parts. To ensure robust design, the insulated-gate bipolar transistor (IGBT), switched-mode power supply (SMPS), C/T (adjusting current), capacitor, and coupling are selected. The IGBT is changed to a field-effect transistor (FET) to enhance the voltage applied to the induction heating system, and a dual-safety device is added to the SMPS. For C/T (adjusting current), the turns ratio is adjusted to ensure an appropriate amount of induced current. The capacitor is replaced by a product with heat resistance and durability; further, coupling with a water-resistant structure is improved such that the connecting parts are not easily destroyed. The ground connection is chosen for management priority.

• Journal of Communications and Networks
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• v.10 no.4
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• pp.455-464
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• 2008

To provide network services consistently under various network failures, enterprise networks increasingly utilize path diversity through multi-homing. As a result, multi-homed non-transit autonomous systems become to surpass single-homed networks in number. In this paper, we address an inevitable problem that occurs when networks with multiple entry points deploy firewalls in their borders. The majority of today's firewalls use stateful inspection that exploits connection state for fine-grained control. However, stateful inspection has a topological restriction such that outgoing and incoming traffic of a connection should pass through a single firewall to execute desired packet filtering operation. Multi-homed networking environments suffer from this restriction and BGP policies provide only coarse control over communication paths. Due to these features and the characteristics of datagram routing, there exists a real possibility of asymmetric routing. This mismatch between the exit and entry firewalls for a connection causes connection establishment failures. In this paper, we formulate this phenomenon into a state-sharing problem among multiple fire walls under asymmetric routing condition. To solve this problem, we propose a stateful inspection protocol that requires very low processing and messaging overhead. Our protocol consists of the following two phases: 1) Generation of a TCP SYN cookie marked with the firewall identification number upon a SYN packet arrival, and 2) state sharing triggered by a SYN/ACK packet arrival in the absence of the trail of its initial SYN packet. We demonstrate that our protocol is scalable, robust, and simple enough to be deployed for high speed networks. It also transparently works under any client-server configurations. Last but not least, we present experimental results through a prototype implementation.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.266-271
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• 2014

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.

• Journal of Advanced Navigation Technology
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• v.22 no.3
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• pp.205-212
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• 2018

Spontaneous ignition is not only severe economic damage but also a typical plant damage caused by harmful gases generated during the fire. Because coal is porous, it causes oxygen to be absorbed in the amount of oxygen per unit weight of oxygen, resulting in low humidity and low thermal conductivity. The cause and effect of spontaneous ignition are very complex, so it is difficult to prevent it beforehand and once it is difficult to digest it, it is difficult to digest it. This study examines structural safety by conducting a structural analysis of the cooling ball system to prevent spontaneous combustion of coal stockpile plants and external pressures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.5
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• pp.383-390
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• 2013

The reduction of the maximum acceleration which causes shock for a missile is very important to prevent abnormal operation of a missile and decrease size and cost of missile components. Because the maximum acceleration created by operation of an ejection gas generator occurs in the initial ejection stage, the design parameters which affect initial ejection stage were examined. The igniter and the nozzle closure were selected as design parameters of a gas generator. The maximum acceleration created by the gas generator was examined experimentally by changing of the design parameters. Finally the reduction effect of the maximum acceleration was compared quantitatively by static fire test of a gas generator. The maximum acceleration of the best model which was applied to each optimal design parameter was about 68% reduced than that of the reference model.