• Korean Journal of Construction Engineering and Management
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• v.16 no.3
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• pp.101-112
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• 2015

In the 1950s, the concept of configuration management (CM) was started by the US Department of Defense (DOD). Later, it has begun to be applied in aerospace, software, engineering, construction, and nuclear power industry. However, configuration management (CM) in the Korean nuclear industry was firstly utilized in 2006 only for selected parts of facilities, while the US nuclear industry has applied CM for the facilities' entire systems since 1990s. Furthermore, configuration management (CM) is in its conceptual stage in the Korean nuclear industry because of ambiguous CM concepts, lacks of CM professional manpower, non-computerization, and inadequacy of CM procedures and processes. In order to address this issues, seven industries (including defense, aerospace, software, engineering, architecture, civil engineering, nuclear power) that utilize the concept of configuration management (CM) were compared and analyzed based on the CM purpose, technique, and life-cycle perspectives. By an extensive literature review and expert interviews, this paper developed a framework of configuration management (CM) for the nuclear industry. And also, a list of functions based on life-cycle stages and CM techniques are developed for clarifying CM framework in order to promote practical applications.

• Fire Science and Engineering
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• v.29 no.6
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• pp.57-64
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• 2015

Carbon dioxide extinguishing systems are broadly used for onshore and offshore fire accidents because of excellent performance and low cost. However, there is risk with carbon dioxide systems, which have caused many injuries and deaths by suffocation associated with industrial and marine fire protection applications. In this study, a numerical analysis was performed to predict the fire suppression characteristics of a carbon dioxide system in the compressor room of ships. A double protection safety system is suggested to prevent suffocation accidents from carbon dioxide extinguishing systems. Four scenarios were selected to study the variation of the heat release rate, maximum temperature, a $CO_2$ and $O_2$ mole fraction, and fire suppression characteristics with the carbon dioxide system. The importance of proper design is suggested for a ventilation system in the compressor room of ships.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5541-5549
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• 2015

This paper introduces a safer and more power efficient heater by using induction heating, to apply to the semiconductor wafer fabrication exhaust gas cleaning system. The exhaust gas cleaning system is currently made with filament heater that generates an endothermic reaction of N2 gas for the removal of moisture. Induction theory, through the bases of theoretical optimization and electronic implementation, is applied in the design of the induction heater specifically for the semiconductor wafer exhaust system. The new induction heating design provides a solution to the issues with the current energy inefficient, unreliable, and unsafe design. A robust and calibrated design of the induction heater is used to optimize the energy consumption. Optimization is based on the calibrated ZVS induction circuit design specified by the resonant frequency of the exhaust pipe. The fail-safe energy limiter embedded in the system uses a voltage regulator through the feedback of the MOSFET control, which allows the system performance to operate within the specification of the N2 Heater unit. A specification and performance comparison from current conventional filament heater is made with the calibrated induction heater design for numerical analysis and the proof of a better design.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.253-259
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• 2018

In February 2014, the rudder upper stock and the nut of a passenger ship were released and an accident occurred. That accident occurred because the steering gear of passenger ships that was intended to move many passengers. The accidents due to steering gear was zero according to 2010-2016 statistics. There is no rules prevent loosening of the upper rudder nut in "Ship Safety Act" and "Structural standard of steel ship". Since the accident, the Korea register has been revised to the joining method in Part 5 Chapter 7 of the rules in the classification of steel ships. In the field survey of 12 passenger ships operating on Mokpo and surrounding islands, the welding method was applied in the cases as the fastening method. The fastening type was equipped with two C-type structures. It was structured to be difficult to access. The NAS 3350 test was conducted to investigate ways to prevent homologous accident considering the characteristic of passenger ships that need to lift or unload rides once a year.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.279-285
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• 2016

With the development of nanotechnology, the amount of nanomaterials increases and the problems of environment and the toxic property associated with it have become a social problem. But regulations and laws of nanomaterials have not yet been established. The purpose of this study is to utilize as the database of safety guidelines for research activities' workers associated with nanomaterials to conduct a behavior evaluation of aluminium oxide, which is most widely used in thirteen kinds of WPMN manufactured nanomaterials in the country. The experiment proceeds in the chamber reduced to 1/6 size of the actual laboratory, the test method was performed in NIOSH 0500. As the results of the study, the mass concentration was in inverse proportion to the particle size of the nanomaterials. And the mass concentration during the operation of ventilation equipment was reduced to about 1/8 times. In the future, it can be utilized as the database of safety guidelines for research activities' workers associated with nanomaterials. However, in order to increase the reliability of the study, the experiment of the mass concentration by particle size and Condensation Particle Counters will be needed additionally.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.175-185
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• 2017

As the gas is manufactured, handled and used more often due to the continuous increase of gas, the related facility gets expanded and more complex causing small and big accident which causes economic loss including damage for humans and materials. The gas pipeline, the most common gas facility, has the biggest risk of accidents. Especially in the urban area and densely populated areas, the accident due to the high pressure pipeline may cause even more serious damages. To prevent the accident caused by the buried pipeline, it is required for the relevant authorities to evaluate the damage and risk of the whole pipeline system effectively. A risk is usually defined as a possibility or probability of an undesired event happening, and there is always a risk even when the probability of failure is set low once the pipeline is installed or under operation. It is reported that the accident caused by the failure of the pipeline rarely happens, however, it is important to minimize the rate of accidents by analyzing the reason of failure as it could cause a huge damage of humans and property. Therefore, the paper rated the risk of pipelines with quantitative numbers using the qualitative risk analysis method of the Scoring Model. It is assumed that the result could be effectively used for practical maintenance and management of pipelines securing the safety of the pipes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.927-935
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• 2019

Screw-failure accidents in small ships frequently occur in coastal waters. In particular, vessels' propulsion systems are frequently coiled due to objects such as fish-nets and ropes that float on the sea. The failure of the ship's propulsion system can cause primary accidents such as ship operation delays and drifting due to loss of power; furthermore, the possibility of secondary accidents such as those involving operators in the underwater removal of rope stuck in a propeller. Ships that do not have the proper tools to solve these problems must be either lifted onto land to be repaired or divers must dive directly under the ship to solve the problem. Accordingly, some small vessels have been equipped with rope-cutter devices on the propeller shaft to prevent ship propeller system accidents in recent years; however, they are not being applied efficiently due to the cost and time of installation. To solve these problems, this study develops an underwater rope-cutter device and controller for the removal of propeller and shaft foreign material in small vessels. This device has simple structures that use the principle of a saw. Meteor gears and crank pins were used for the straight-line rotation of saw blades of the underwater rope-cutters to allow for long strokes. Furthermore, the underwater rope-cutting machines can be operated by being connected to the ship battery. The user, a non-professional, can ensure convenience and stability by applying reverse current prevention and a speed control circuit so that it can be used more conveniently and safely.

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.87-93
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• 2017

This study was conducted to analyze thermal effects for the structure of portable butane gas stoves in accordance with the introduction of safety standard to protect gas accidents that were caused by using oversized grills. The temperatures of oversized grill, cartridge and cover of cartridge coupling part were measured with stoves that heat sink was installed the inside of cover of cartridge coupling part and had different height of tripods. The trend of measured temperatures affected by thermal effects of grill and flame was analyzed. The condition of using portable butane gas stove safely is that the distance between grill and cover of cartridge coupling part should be about 28 mm and over. In contrast, when the distance between grill and cover of cartridge coupling part would be shorter, thermal effects of not only grill but also flame could affect the cartridge directly. In this case, the danger that could cause gas accident would be higher. When heat sink was installed the inside of cover of cartridge coupling part, it was effective on reducing of thermal effects. However, it still had the danger of explosive gas accident of cartridge due to overheating.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.647-655
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• 2021

The IMO (International Maritime Organization) is discussing the improvement of energy ef iciency of ships in order to reduce greenhouse gas emissions from ships. Currently, by applying an ORC power generation system using waste heat generated from ships, high energy conversion efficiency can be expected from ships. This technology uses an organic medium based on Freon or hydrocarbons as the working fluid, which evaporates at a lower temperature range than water. Through this, it is possible to generate steam (gas) and generate power at a low and low temperature relatively. In this study, the analysis of heat flow between the refrigerant and waste heat in the ORC power generation system, which is an organic Rankine cycle, is analyzed using 3D simulation techniques to determine the temperature change, velocity change, pressure change, and mass change of the fluid flowing of the WHRU (Waste Heat Recovery Unit) inside and the outside the structure. The purpose of this study is to analyze how the mass change affects the structure, and this study analyzed the heat transfer of the heat exchanger from the refrigerant and the exhaust gas of the ship's main engine in the ORC power generation system using this technique.

• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.84-91
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• 2021

In the 21st century, a number of storm and flood disasters caused by rapidly changing climate change is increasing, and the number of flood accidents at construction sites is also increasing. However, no specific reduction measures have been presented and thereby safety management to prevent flood accident need to be improved. Therefore, in this study, the inundation pattern by downpour at the excavation site was interpreted and the inundation risk quantification method was used to classify the risk magnitude. Finally, using the fish-bone diagram, we derived the major reasons of inundation accident at construction site systematically. The simulation results showed that the inundation depths of small-scale excavation sites and excavation sites exceeded 3 m due to the fluid flowing through the excavation surface. In addition, depending on the excavation site, a high velocity temporarily observed and decreased due to the storage effect, or high velocity surpassing 10 m/s continued. Since this type of flooding can pose a risk to most or all workers, if proper management measures are insufficient, fatal damage to life and property could occur. Consideration of the roots of these disasters is judged to be helpful in understanding the causes of inundation accidents that result in casualties and presenting accident reduction measures.