• Journal of the Korean Institute of Gas
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• v.25 no.2
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• pp.42-51
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• 2021

Facilities that supply specialty gases used in semiconductor manufacturing mainly handles with hazardous and dangerous substances with flammable, toxic, and corrosive properties, and gas cabinets are mainly used as such supply facilities. The effects of the supply facilities were analyzed for each leak through the rupture disk in the gas cabinet and a leak where the leak hole. In this case, gas leaked to the outside depending on the leak area. It is a factor that creates a risk depending on the concentration of the leaked gas. Depending on the risk of leakage, all measures such as safe operation procedures should be reviewed again.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.477-482
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• 2021

The integrated underground space map system provides information on infrastructure that requires security, but to prevent rupture accidents during excavation work at the underground construction site, it must provide information on all underground facilities on the site. Providing additional information other than the object of interest to the user is a factor that increases the risk of information leakage of security data. In this paper, we design the visualization filtering method that when visualizing the integrated underground space map in the field, the visualization of entire underground facilities of interest to workers is performed, but visualization of other underground facilities is minimized to minimize the risk of security data information leakage. To this end, a visualization area of a certain distance for each of the underground facilities of interest was created, and an integrated visualization filter was created with spatial union operation. When the integrated underground map is output on the screen, only the objects located within the filter area are visualized using the generated filter information, and objects that exist outside are not visualized, thereby minimizing the provision of information to the user.

• Journal of Hydrogen and New Energy
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• v.35 no.3
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• pp.324-335
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• 2024

The container package type sealed water electrolysis production system installs mechanical balance of plant and electrical balance of plant as an integrated unit to enable independent operation within the package module. The auxiliary equipment required to operate the water electrolysis system must be integrated to reduce the installation area and shorten the installation time. At this time, as leak risk factors are placed in a dense space, when a hydrogen gas leak accident occurs, it can have a mutual influence on other adjacent facilities, so it contains various risk factors. In this study, when a gas leak occurs in a container packaged water electrolysis system, possible sources of leakage in the system according to the KS C IEC 60079-10-1:2015 and KGS GC101 standards were identified, and the leak rate and leak characteristics were calculated. did. The hazardous area and its range were calculated according to ventilation and dilution characteristics. In order to optimize ventilation characteristics, design of experiment was used to analyze the influence to evaluate the adequacy of ventilation, and overseas ventilation standards were analyzed and compared. In addition, the optimal ventilation structure and characteristics of the container packaged water electrolysis system were presented according to the results of the experimental design method.

• Journal of the Korea Safety Management & Science
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• v.26 no.3
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• pp.51-57
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• 2024

The purpose of this study is to compare and analyze the impact range of explosion damage due to gas leaks at LPG filling stations, focusing on propane and butane, which are components of vehicle LPG. The scenarios were designed based on the explosion incident at an LPG filling station in Gangwon-do, where an actual gas leak accident occurred, resulting in Scenario I and Scenario II. The ALOHA program, developed by the U.S. National Oceanic and Atmospheric Administration (NOAA), was used as the tool to analyze the impact range of the explosion damage for both substances. The results of the study indicated that, under identical conditions, propane had a wider impact range of damage than butane. This is presumed to be due to the greater explosion energy of propane, attributable to its physicochemical properties. Therefore, when preparing for LPG leak accidents, measures for propane need to be prioritized. As safety measures for propane, two suggestions were made to minimize human casualties. First, from a preventive perspective, it is suggested to educate workers about propane. Second, from the perspective of response measures and damage minimization, it is suggested to thoroughly prepare emergency evacuation and rescue plans, evacuation routes, designated shelters, and emergency response teams. This study compares and analyzes the impact range of radiative heat damage based on LPG components. However, hazardous accidents are critically influenced by the type of leaking substance, the form of the leak, and meteorological factors affecting the diffusion pattern of the substance. Therefore, for future research, it is proposed to model various leakage scenarios for the same substance to conduct a comprehensive risk assessment.

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.43-51
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• 2017

Recently, ammonia leak occurred frequently in the domestic refrigeration manufacturing facilities. Ammonia caused great damage to the environment and human health in the event of an accident as combustible gases and toxic gases. After considering the types of ammonia accidents of domestic refrigeration manufacturing facilities and selected accident scenarios and to analyze the risk analysis through Impact range estimates and frequency analysis and there was a need to establish measures to minimize accident damage. In this study, depending on the method of analysis quantitative risk assessment we analyzed the risk of the receiver tank of ammonia system. Scenario analysis conditions were set according to the 'Technical guidelines for the selection of accident scenario' under the chemicals control act and 'Guidelines for chemical process quantitative risk analysis' of center for chemical process safety. The risk estimates were utilized for consequence analysis and frequency analysis by SAFETI program of DNV, event tree analysis methodology and part count methodology. The individual risk of ammonia system was derived as 7.71E-04 / yr, social risk were derived as 1.17E-03 / yr. The derived risk was confirmed to apply as low as reasonably practicable of the national fire protection association and through risk calculation, it can be used as a way to minimize accidents ammonia leakage accident damage.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.24-29
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• 2019

Purpose: To evaluate the characteristics and the risk factors of early onset subsequent vertebral compression fractures after percutaneous vertebroplasty. Materials and Methods: A total of 44 patients, who had a new subsequent vertebral fracture after percutaneous vertebroplasty for an osteoporotic vertebral compression fracture between January 2013 and December 2015, were recruited. The patients were divided into two groups according to the onset period of subsequent fracture. The number of patients who had a fracture within 3 months following vertebroplasty were 22 cases (Group A); after 3 months were 22 cases (Group B). Variables, including age, sex, bone mineral density (BMD), body mass index (BMI), preexisting vertebral compression fracture, location of the initial fracture, intradiscal cement leakage, injected cement volume, restoration of vertebral body height, and correction of kyphosis, in the two groups were analyzed and compared retrospectively. Results: The age, sex, BMD, BMI, preexisting vertebral compression fracture, location of the initial fracture, intradiscal cement leakage, and correction of kyphosis were similar in the two groups. Both a greater volume of bone cement injected and a greater degree of vertebral height restoration contributed significantly to the risk of fracture within 3 months. Conclusion: The cement volume and degree of height restoration are risk factors for early onset fracture at the adjacent vertebrae after percutaneous vertebroplasty and close attention is needed during the follow-up period.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.6
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• pp.835-844
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• 2018

Recently, as the number of smartphone users has been increasing worldwide, various services such as electronic payment, internet use, and financial settlement are being used as a smartphone. In addition, researches for home appliance control and automobile control using smartphone are conducted. As such, smartphone users can enjoy a more convenient life, but by hacking smartphones, tapping texts and conversations on smartphones, tracking location through spy apps, DDoS attacks using smartphones, and malicious apps When a message is received at a specific telephone number when using a micropayment, the corresponding text message is transmitted to a remote server, thereby increasing the risk of leakage of personal information and the like. Therefore, in this paper, we define the risk factors of the smartphone that are caused by the internal and external environmental, physical, contents (apps) of the smartphone through the smartphone that we use in real life, We propose a method to check vulnerability of smartphone security solution such as CC evaluation and the most effective response technique for each risk of smartphone by defining the technique.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.141-149
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• 2018

In a PCB factory, there is a corrosive chemical substance supply system that can causes major leakage accidents. These accidents can give rise to shut down the factory and do residents damage that cause enormous loss of properties. To mitigate these risks, it is necessary to provide a chemical disaster prevention system. Moreover, after considering the situation and environment of the production site, it is of great importance to build an optimal chemical accident prevention system by reflecting risk reduction measures from the point of process design and by assessing quantitative risk based on reliability data. However, because there was no established database of the reliability about facilities and equipment that can be used in the domestic, the business site and consulting organization had being used the reliability data such as USA CCPS(Center for Chemical Process Safety). In these days, Korean institutes are studying on reliability data utilization method of quantitative risk assessment for preventing chemical accidents and domestic utilization algorithms and storage bed of reliability data. This study presents samples of reliability database about the chemical substance supply system that constructed from the history data such as failure, maintenance for 10 years at a PCB factory. Also, this work proposes the safety design criteria for supply facilities of corrosive chemical substance by assessing quantitative risk on the basis of the reliability data.

• Journal of Hydrogen and New Energy
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• v.31 no.6
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• pp.605-613
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• 2020

In July and October of this year, the government announced the 'Green new deal plan within the Korean new deal policy' and 'Strategies for proliferation of future vehicles and market preoccupation'. And, in response to changes in the global climate agreement, it has decided to expand green mobility such as electric vehicles and hydrogen electric vehicles with the aim of a "net-zero" society. Accordingly, the goal is to build 310 hydrogen refueling stations along with the supply of 60,000 hydrogen vehicles in 2022, and the hydrogen infrastructure is being expanded. however, it is difficult to secure hydrogen infrastructure due to expensive construction costs and difficulty the selection of a site. In Korea, it is possible to build a mobile hydrogen station according to the safety standards covering special case of the Ministry of Industry. Since the mobile hydrogen station can be charged while moving between authorized place, it has the advantage of being able to meet a large number of demands with only one hydrogen refueling station, so it is proposed as a model suitable for the early market of hydrogen infrastructure. This study demonstrates the establishment of a hydrogen refueling station by deriving a virtual accident scenario for leakage and catastrupture for each facility for the risk factors in a mobile hydrogen station, and performing a quantitative risk assessment through the derived scenario. Through the virtual accident scenario, direction of demonstration and implications for the construction of a mobile hydrogen refueling station were derived.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.14-19
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• 2014

Recently, many renewable energy generating businesses are ongoing progress due to the introduction of the RPS(Renewable Portfolio Standards) as well as the needs of environmentally friendly energy resources. Researches on photovoltaic system are actively being processed since the photovoltaic system is relatively easy to install and becomes commercialized in many domestic application areas. Furthermore, the floating photovoltaic system is likely to be installed more actively since the conventional photovoltaic system requires relatively large areas of land. Also, the floating photovoltaic system is more efficient than photovoltaic system installed in land due to the operation in lower temperature. However, safety problems such as electric shock could arise since the cable should be installed in the water. In this paper, the leakage current and the voltage rising are measured and analyzed for the case when the cables are damaged connecting the floating photovoltaic system to the grid.