• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.191-195
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• 2018

By using an ANSYS product suite (CFX, Ansys Multiphysics), which is a powerful tool for multiphysics analysis of complicated physical phenomena, we performed a structural stress analysis based on fluid flow and heat transfer phenomena within a quick connect/disconnect (QC/DC) bellows system. Considering the extremely low temperatures in the QC/DC environment, an approach to the problem based on complex multi-physics phenomena, where different phenomena interact with each other, is crucial. Therefore, we use a numerical analysis technique where fluid-thermal-structural interactions are combined. In conclusion, when low temperature fluids flow inside bellows, the expected service life is conspicuously reduced due to the thermal stress caused by heat transfer. Therefore, in future research, a structure with considerably reduced thermal stress by robust design optimization will be derived.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.51-58
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• 2004

Due to the changes in market place, new business types(e.g. e-business} have been rapidly emerged and increased. However, those new business types have not much been emerged in port and logistics related industries, and adoption rate of e-business in this area is very low, compared to other industries. Thus, to promote e-business in this area, many policies have been studied. However, most of previous studies have not been based on industrial structure, and results of these studies have mostly been case by case. Further, there have been no research based on the related theories. As a result, despite many of research and project for shipping and port related e-business, prominent achievements in this area have never to be presented. For these reasons, it am be stated that, first of all, basic studies related to new business types in shipping and port are needed, and then, various policies based on results of those basic studies should be discussed. The aim of this study is to classify business types existed (or expected) in a port related industry, ship bunkering. This taxonomy was based on theories related to business layer(BL) and value chain(VC), and these BL and VC combination enabled to acquire all possible business types.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.298-303
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• 2003

Due to the changes in market place, new business types(e.g. e-business) have been rapidly emerged and increased. However, those new business types have not much been emerged n shipping and port related industries, and adoption rate of e-business in this area is very low, compared to other industries. Thus, to promote e-business in this area. many policies have been studied. However, most of previous studies have not been based on industrial structure, and results of these studies have mostly been case by case. Further, there have been no research based on the related theories. As a result, despite many of research and project for shipping and port related e-business, prominent achievements in this area have never to be presented. For these reasons, it can be stated that, first of all, basic studies related to new business types in shipping and port are needed. For these reasons, it can be stated that, first of all, basic studies related to new business types in shipping and port are needed, and then, various policies based on results of those basic studies should be discussed. The aim of this study is to classify business types existed (or expected) in a port related industry, ship bunkering. This taxonomy was based on theories related to business layer(BL) and value chain(VC), and these BL and VC combination enabled to acquire all possible business types.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.10-20
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• 2022

About 21% of domestic chemical accidents are caused by transport vehicles for the past 10 years in Korea. Also, ammonia is a chemical substance with the largest number of accidents, 82 out of 672. In this study, supposed seasonal alternative scenario and worst scenario in case of releasing ammonia during bunkering it from tank lorry to fishing vessel and interpreted seasonal impact and range through Python, ALOHA, Probit analysis. Radiation impact range of possibility for 2nd burn and for maximum radiation in winter scenario, which is one of the alternative scenarios, was the highest(range: 41m, radiation: 5.01kW/m²) while overpressure impact was less than minimum standard of impact. And toxicity impact range(EPRG-2) of the summer scenario was the widest(5.0km) and took a very high death rate near accident area(port area, tourist area) according to Probit analysis. the wort scenario had a similar impact and range of summer scenario.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.248-253
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• 2023

Most offshore platforms utilize chain mooring systems for position keeping. However, information regarding related design modification processes is scarce in literature. This study focuses on the floating liquefied natural gas (LNG) bunkering terminal (FLBT) as the target of shore platform and analyzes the corresponding initial mooring design and model tests via numerical simulations. Subsequently, based on the modified design conditions, a new mooring system design is proposed. Adjusting the main direction of the mooring line bundle according to the dominant environmental direction is found to significantly reduce the mooring design load. Even turret-moored offshore platforms are exposed to beam sea conditions, leading to high mooring tension due to motions in beam sea conditions. Collinear environmental conditions cannot be considered as design conditions. Mooring design loads occur under complex conditions of wind, waves, and currents in different environmental directions. Therefore, it is essential appropriately assign the roll damping coefficients during mooring analysis because the roll has a significant effect on mooring tension.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.174-179
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• 2016

To protect the ocean environment, the use of liquefied natural gas (LNG) carriers, bunkering ships, and fueled ships is increasing. Recently, Korean shipbuilders have developed and supplied a partial reliquefaction facility for boil-off-gas (BOG). Despite reasonable insulation, heat leakage in vessel storage tanks causes LNG to be continuously evaporated as BOG. This research analyzed the maximum liquid yield rate for various partial reliquefaction systems (PRS) and considered related factors affecting yields. The results showed a liquid yield of 48.7% from an indirect PRS system (heat exchanges between cold flash gas and compressed natural gas), and 41% from a direct PRS system (BOG is mixed with flash gas and discharged from a liquid-vapor separator). The primary factor affecting liquid yield was heat exchanger effectiveness; the exchanger's efficiency and insulation characteristics directly affect the performance of BOG reliquefaction systems.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.10
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• pp.1054-1061
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• 2015

The International Maritime Organization (IMO) has been regulating emissions by making mandatory the compliance with institutions aimed at protecting air quality such as the Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and Tier III. Under the circumstances, one of the response measures considered to be the most feasible is the replacement of existing marine fuel with Liquefied Natural Gas (LNG). The industry has been preemptively building infrastructure and developing and spreading engine technology to enable the use of LNG-fueled ships. The IMO, in turn, recently adopted the International Code of Safety for Ships Using Gases or Other Low-Flash-Point Fuels (IGF Code) as an institutional measure. Thus, it is required to comply with regulations on safety-related design and systems focused on response against potential risk for LNG-fueled ships, in which low-flash-point fuel is handled in the engine room. Especially, the Standards of Training, Certification and Watchkeeping (STCW) Convention was amended accordingly. It has adopted the qualification and training requirements for seafarers who are to provide service aboard ships subject to the IGF Code exemplified by LNG-fueled ships. The expansion in the use of LNG-fueled ships and relevant facilities in fact is expected to increase demand for talents. Thus, the time is ripe to develop methods to set up appropriate STCW training courses for seafarers who board ships subject to the IGF Code. In this study, the STCW Convention and existing STCW training courses applied to seafarers offering service aboard ships subject to the IGF Code are reviewed. The results were reflected to propose ways to design new STCW training courses needed for ships subject to the IGF Code and to identify and improve insufficiencies of the STCW Convention in relation to the IGF Code.

• Journal of Korea Port Economic Association
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• v.25 no.1
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• pp.29-46
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• 2009

According to construction work of No. 2 Lotte world, the alternative pier is under construction in Dongsam-dong Yeongdo-gu to accommodate small boats. As a result of that, in order to procure route of small boats passage,0-2 Anchorage used to bunkering or waiting for berth should be reduced, 220m. It is expected that the risk of passage and congestion around the anchorage could be increased because of the traffic of small boat using the alternative pier. Therefore, it is needed to enlarge the O-2 Anchorage 250m toward to inner breakwater. According to result of analyzing traffic circumstance and weather condition of anchorage near the Busan inner fairway, and to procure of alternative anchorage in order to resolve the problem caused by reduction of O-2 Anchorage, no problems incurred. In conclusion, reduction & enlargement of area of new O-2 Anchorage is expected to resolving of congestion & reducing of risk of traffic at O-2 Anchorage, and to operating O-2 Anchorage, efficiently.

• Journal of Hydrogen and New Energy
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• v.33 no.3
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• pp.247-254
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• 2022

Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m³ class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H₂) could also be lowered by about 41.7% compared with liquid hydrogen storage.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.3
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• pp.161-169
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• 2024

In order to investigate cavitation performance for the azimuth thruster in Large Cavitation Tunnel (LCT), the cavitation test apparatus was designed and manufactured. Generally the model scale is determined by the pod dynamometer with about 70mm diameter. Recently as ships with azimuth thruster have become bigger, the problem of the model ship installation was occurred. The model ship with pod dynamometer couldn't be installed in the LCT test section. The cavitation test apparatus and technique which can conduct the cavitation test without pod dynamometer were developed. The cavitation tests were conducted in torque identity method instead of thrust identity method. The target ship with azimuth thruster is 18K LNG bunkering vessel. As the full-scale ship test was conducted, the model cavitation tests were conducted at the same operating conditions. The fluctuating pressure levels of the full-scale ship were compared to those of the model tests. Another model cavitation test was conducted in the foreign institute and the cavitation observation results were compared to those of LCT. Through the comparison with the existing results, it is thought that the cavitation test for the azimuth thruster can be conducted in torque identity method.