• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.234-238
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• 2015

When we use a Finite Elements Method (FEM) to solve a linear static analysis problem, number of elements need to be sufficiently small for convergence of the solution. If we analysis a part, whose curvature is varying heavily, we face to determine how small the elements size is, because the calculated stress is increased as the elements are smaller. In this case, we need to analysis with mesh insensitive method, stress linearization. We can get a solution that is not varying with the elements size if the size is smaller than a certain level. In this paper, we evaluate a pressure vessel having geometrical discontinuities using stress linearization. First, we analysis the vessel with global model, including all part of the vessel, using large shell elements. Second, we analysis the local part of the vessel, which is the small part occurring maximum stress, using small continuum elements. Last, we evaluate the safety of the pressure vessel according to the ASME Sec. VIII Div 2.

• Journal of the Korea Furniture Society
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• v.19 no.2
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• pp.111-115
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• 2008

An experiment was conducted to know ultra-pure distilled water penetration depth through large vessel, small vessel, latewood fiber and earlywood fiber in longitudinal direction of Castanea crenata. In heartwood, latewood fiber transported water more than large and small vessel. While in sapwood, small vessel conduction depth was found the highest. Penetration depth of water after 15.0 seconds, no significant difference was observed among earlywood fiber, latewood fiber and earlywood vessel. Whilst in heartwood, no statistical difference was observed among earlywood fiber, latewood fiber and earlywood vessel. At the beginning, the speed of water penetration was high and then gradually decreased.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.555-561
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• 2023

In this study, we proposed a standard model for the design, construction and demonstration of the technology development and substantiation of small hydrogen powered vessel in order to respond to the alternative fuel-using vessel market that requires the use of low-carbon/carbon-free fuel as a greenhouse gas reduction measure. The hydrogen fuel cell-based electric propulsion system developed through this is optimized through performance and durability tests on the land-based test site (LBTS), and the electric propulsion system applied to this result is mounted on a small hydrogen propulsion vessel and operated. Simultaneously, through the digital twin technology between the LBTS and the hydrogen-propelled vessel on the sea, the technology that can predict and diagnose the problems that can occur in the electric propulsion system of the vessel is applied to carry out the empirical study of the hydrogen-propelled vessel. In addition, we propose a commercialization model by analyzing the economic feasibility of the demonstration vessel.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.2
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• pp.136-143
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• 2013

The analysis of the written verdicts in recent five years was conducted to obtain preventive measures of collision between fishing vessel and non fishing vessel. As a result, a collision much happened in offshore trap for fishing vessel and below 5,000 tons of small and medium class for non fishing vessel. A person involved in a marine accident occupied 68% in sixth class deck officer and small boat operator for fishing vessel and 29% in third class deck officer for non fishing vessel. 90% of the collision happened in a underway by operating state and 84% in sight of one another by visibility state. The systemic radar training was required since 47% of the collisions was occurred on the condition of radar operation in fishing vessel. The main cause of poor lookout was a intensive fishing and poor lookout on movement by radar for fishing vessel and one man watch system and no recognition of one another by radar for non fishing vessel. This result is expected to contribute for the decrease of collision.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.1
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• pp.34-43
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• 2012

In order to establish order in fishing industry by cracking down on illegal fishing vessels effectively, it is an essential requirement to identify marking such as the name of fishing vessel and a port of register more easily. Accordingly, it is quite natural that markings on fishing vessels should be marked clearly in an appropriate size on an appropriate site in order for them to be distinguished on the air such as from planes as well as on the sea. Actually, when examining marks such as the name of a vessel which are operating in the country, marks of most fishing vessels are too small as they cannot be distinguished with the naked eye even very closely. There is no coastal fishing vessel which marks the name of fishing vessel on the upper part in order to distinguish it from planes. Fishing vessel law generally which regulates the basic laws about shipbuilding regulates marks on fishing vessel, and fisheries law only regulates sign boards of fishing vessels. Problems and improvement of the marking system on fishing vessels suggested by this paper are as follows. First, in order to contribute to establish order in fishing industry, it would be desirable to tighten standards in fisheries law besides the fishing vessel law. Second, it is difficult to distinguish marks such as the name of a vessel as relevant laws allow fishers to make such marks too small. It is necessary to set the standard for marks larger than those regulated by the international treaty. Third, the relevant laws do not regulate a letter form of marks. Therefore, it becomes a factor to make small marks hard to be distinguished more. It is necessary to decide a clear letter form. Fourth, there is insufficient detailed international standards about the marking system. It is necessary to regulate a detailed standard.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.203-203
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• 2021

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.2
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• pp.147-155
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• 1999

In this study, the stability analysis of a fishing vessel in a seaway was done. The stability analysis is an important item in the ship design, and so the ship registers of each nation constrain the ships to be followed the stability criterion. Stability variation, exciting forces due to wave and wind, and the broaching phenomena cause the capsizing of a ship. In this study, the stability analysis to study of the capsizing of a fishing vessel was performed. The relation between the speed of the ship and the wave length, that makes the encountering frequency vanish, was obtained. It was found that the encountering frequency tend to be zero when the wave whose length and direction are similar to those of ship. In this case, the possibility of dangerous situation becomes high. The calculated restoring arm becomes small when the ship is located near the wave crest. In general, the selected small fishing vessel is better than the large ship with respect to the stability, however the wave height becomes relatively high because of her small length Kim(l994) calculated the stability variation of the large cargo ship, the results of which showed the changes in stability great. But in the selected small fishing vessel in this study, the changes was small in comparison with the larger ship. This reason seems to be the shape of her midship section. In large cargo ships, the block coefficient is large, but that of the fishing vessel is relatively small and the small fishing vessel has chine, therefore the center of buoyancy moves much when the ship is inclined. It is desirable that the dynamic stability analysis for a fishing vessel, whose speed and direction are similar to those of waves, shall be done in the near future.

• Journal of Navigation and Port Research
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• v.27 no.6
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• pp.693-700
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• 2003

Universal AIS, which has been adopted officially for automatic identification systems among regulated ships by SOLAS, should be installed, for example, on all passenger ships over 300 tons engaged in international voyage and over 500 tons in domestic voyage, sequentially from 2002 to 2004. We must not overlook the fact than-ruled regions by regional authorities in the case of VTS. Actually a major portion of accidents have happened in small vessels like fishing vessels. However, they are not equipped with automatic identification tools, due to the high costs of the equipment for identifying purposes, as well as the absence of regulation In this paper, we researched the alternative of automatic identification for small vessel instead of universal AIS. We analyzed the requirement of automatic identification for small vessel about wireless communication method, traffic volume, etc. We proposed the identification system for small vessels in local areas and developed the Local Vessel Identification System (LVIS) interoperable with universal AIS using a PDA platform and wireless network.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.185-185
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• 2017

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.176-183
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• 2024

Assessing the stability of small fishing vessels is important to prevent capsize accidents in coastal waters that primarily occur on small fishing vessels. However, the regulations regarding stability assessment for small vessels under 24 m are inadequate according to the domestic Fisheries Act. Based on safety standards issued by the Ministry of Oceans and Fisheries in 2022 to enhance safety and welfare, vessels adhering to the enhanced safety standards for standard ship types are required to establish stability regardless of their length. This study aims to utilize these aforementioned standards to assess the stability of vessels under 24 m, investigating the suitability of applying these criteria to these vessels and examining the impact on various small vessels with different superstructures. Initially, a 4.99-ton fishing vessel designed according to the standard ship type was selected as the subject vessel. Compliance with the standards was evaluated based on the initial stability of the vessel using the transverse metacentric height (GM) and transverse restoring moment arm at the limit angle (GZ_α). Additionally, six types of small vessels with identical hull forms and specifications to the subject vessel were further examined using prevalent superstructure designs in small fishing vessels. The stability of the subject small vessel was also assessed. A study of a 4.99-ton standard fishing vessel confirmed that the safety standards for standard fishing vessels with enhanced safety welfare were applicable to small fishing vessels under 4.99-ton class and that the stability of small fishing vessels with superstructure modifications was not significantly changed.