• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.660-670
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• 2016

This study expresses the necessity of recognizing Pyeongtaek Port as a specific traffic safety area to ensure the safety of the vessels that navigate there using quantitative data. The number of foggy days, pilotage distance, the number of large vessels and the number of fishing vessels that traveled between Pyeongtaek Port and 6 ports chosen as comparative study objects were compared and analyzed. The results showed that Pyeongtaek Port was more frequently affected by restricted visibility. With these perverse conditions, Pyeongtaek Port has a longer pilotage distance than Busan, Busan Newport, Ulsan or Pohang Ports by as much as 3.5-6 times. Especially from May to July, when fisheries were most functional, large vessels were required to navigate in an opposite direction to avoid 35 fishing vessels that were observed, creating an increased possibility for collisions among vessels. Therefore, the navigational safety of Pyeongtaek Port should be further secured by defining the approaching waters as specific traffic safety areas, giving large vessels legal priority over fishing vessels.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.2
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• pp.83-90
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• 2010

The hydrodynamic interaction of two floating bodies in waves freely floating or connected by a rigid link is studied by using a boundary element method in the frequency-domain. The exact two-body hydrodynamic coefficients of added mass, wave damping and exciting force are calculated from the radiation-diffraction potential solution of the improved Green integral equation associated with the free surface Green function. The irregular frequencies in the conventional Green integral equation make it difficult to predict the physical resonance of the fluid in the gap between two bodies floating side by side. However, the improved Green integral equation employed in this study is free of irregular frequencies and always yields the exact solution of the multi-body radiation-diffraction potential boundary value problem. The 6 degree-of-freedom motions of two bodies freely floating side by side or connected parallel by a rigid link have been calculated for the incident wave frequencies ranging from 0.1 to 5 radians per second in head, left and right bow quartering seas. The 6-component load of the rigid link have also been presented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.167-173
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• 2016

This study aims to present methodology for determining the appropriate anchorage area through the simulation reproduces the maritime transport environment, and analysis of the adequacy of anchorage applied at Ulsan E anchorage, suggests the formula of anchorage occupancy rater per hour and necessary anchorage area for this purpose. And configured simulation algorithm and modeling using MATLAB program, and applied Ulsan E anchorage, compared anchorage area with anchorage occupancy rate per hour. As a result, E1 necessary anchorage is 1.41 times, E2 necessary anchorage is 0.90 times and E3 necessary anchorage is 0.96 times compared to total anchorage area. If the result of adequacy analysis of anchor area reflect anchorage design criteria, it is determined to be helpful for the safety of the vessel using the anchorage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.47-52
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• 2011

On the high seas, under international law, a ship is subject to the jurisdiction of the state whose flag she flies. Vessels of any flag are free to navigate the high seas without interference from other states. Thus, there are certain limits of coastal state's exercising law enforcement jurisdiction over a foreign flag vessel on the high seas. However, there are exceptions to exclusive flag state jurisdiction. One of them is the theory of constructive presence. The other is theory of partial execution. Korea Coast Guard's law enforcement authority should be exercised more actively based on those theories supported by the international cases.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.432-438
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• 2017

The primary objective of the current work was to develop a standardized retrofit hull form capable of saving energy based on existing vessels. The bow shape of existing vessels was investigated, giving consideration to design draft and speed. Resistance performances were assessed for existing vessels according to operating conditions. Commercial CFD codes and model test materials were used for assessment of effective power. Three retrofit hull forms with minimum resistance were selected given real operating conditions. These vessels were named after customized ready-made hull forms to enable ship owners to make easier choices. The effective power of each vessel was estimated under real operating conditions. Subjects were operated with the lowest draft, and performance for retrofit No. 3 showed an 11-16% improvement in effective power at low speed ranges of 16-18 knots compared to existing vessels. When operated with a middle draft, performance for retrofit No. 3 showed a 6-11% improvement in effective power at low speed ranges compared to existing vessels. When operated with the highest draft, performance for all vessels showed little difference in effective power.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.1-9
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• 2018

All ships should ensure stability in accordance with IMO regulations. However, GM is only used to determine ship stability because it takes a lot of time to validate all regulations. This is a problem given that the safety of vessels cannot be guaranteed, potentially leading to accidents. There is a need for a more intuitive and comprehensive method of confirming the stability of ships. This study developed a stability index that expresses ship stability in one value. An index equation is defined based on the 6 stability criteria for ships prescribed by IMO and the result of calculating the ship stability of a model ship. A stability index has been derived for each loading condition by applying the index equation to the same ship. It can clearly be seen that this stability index appropriately explains the criteria. In other words, it is possible to assess ship stability with one value and confirm whether the ship stability satisfies IMO regulations. This index will help masters and officers more easily and accurately check ship stability.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.403-411
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• 2020

This paper discusses the main findings of the development of the twin-hull Car ferry for island freight and passenger transport. The final model had a 19 m wide beam to create enough space for cars on the deck area and thus, enhance the economic feasibility in the market. The vessel had a V-shape with a bulbous bow to minimize the wave-making resistance and the hydrodynamic performance of the ship was verified through computational fluid dynamics. Multi-objective optimization problems of Pareto simulated annealing were used to achieve a weight reduction of approximately 3.9 % and reduce the manufacturing cost. The main results obtained in this study are expected to be useful to engineers and professionals in related industries interested in research on twin catamaran.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.576-578
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• 2015

This paper propose the help of the secure a clear view and safe navigation of the coastal ship through the sea-fog removal algorithm. Interest in marine accidents and vessel safety has increased in recent Sewol ferry event. According to statistics coastal ship cause of the marine accident when sea fog on the sea did not secure clear view the ship's occur several incidents of collisions between ships and can see that accounts for a high percentage. Algorithm for image exist sea fog is number of studies. but, such studies take up a lot of calculation quantity in the course of performing the algorithm. In this paper, we improve the computational speed of sea fog over the GPU-based technique was removed to suit real-time video. Furthermore, by using GPU, we succeeded in accelerating the simulation 250 times.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.92-93
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• 2005

A contract for the shipbuilding is usually a complicated and involves statement of rights, obligations and responsibilities which each party agrees vis-a vis the other. The ultimate purpose of the contract is the sale and transfer of the finished ship by the builder to the buyer. Contracts for the construction and sale of ships are categorized as contracts for the sale of goods under English, United States, Germany and some countries law. On the other hand, The shipbuilding contract may be classified, not as a contract of sale but as a contract for work and materials under Korea, Japan and some countries law. Especially, most of countries are now well settled with regard to liability of a manufacturer in tort for physical injury and on the other for pure economic loss to remote owners of chattels. Where there is either a breach of contractual warranty or an implied warranty, there may be admiralty jurisdiction, depending once again on the situs of the event and its relationship to traditional maritime activity. Contract principles will be applied to the first type of warranty and tort principles will be applied to the second. First of all, this thesis is dealt with the contents of contract under English Law. Secondly, this thesis is analysed into the liability of shipbuilder in Products Liability under English, American and Korean Law comparisons. In conclusion, the author tries to give some suggestions as countermeasures of Products Liability to the shipbuilder in Korea.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.6
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• pp.788-793
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• 2012

This study was focused on the estimations of air pollutants, such as PM(Particulate matters), SOx(Sulfur Oxides), $CO_2$(Carbon diOxides) and NOx(Nitrogen Oxides), from a diesel propulsion engine installed on a naval vessel. Legislative and regulatory actions for exhaust emissions from ships are being strengthened in international communities and national governments to protect human health and the environment. In this context, various technologies have been developed from all of the nations of the world to meet strict standards. These regulations are based on commercial ship applications and according to size, but are not suitable for military naval vessels, which have much different engine operating conditions and hull architectures. Additionally, there is no international emission control system for military ships. Emission factors have been updated for commercial ship types from work at various research institutes; however, it is difficult to develop emission factors for military vessels because of their characteristics. In this paper, exhaust emissions from diesel engines installed on naval vessels under steady navigation condition were estimated with emission inventory methodology applied to ocean going vessels using fuel-based methods and fuel sulfur content analysis.