• Journal of Distribution Science
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• v.16 no.10
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• pp.31-38
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• 2018

Purpose - The purpose of this paper is to seek some alternative to overcome difficult shipping situations for overcapacity pursuing economy of scale, which is widely spread in world shipping. Research design, data, and methodology - The research method to be adopted is first to review evolution of larger ships in terms of theoretical overview, and shipping market is examined, and it is studied some problems and solutions in relation to larger ship as field research aspects. Results - Supply and demand of shipping market is flexible and unpredictable nature of market. Sometime fierce competition has spread out the market, and shipowner may deploy mega ship in terms of economy of scale, etc., to overcome the difficult market situations. Both carrier and shipper have their own positions in this matter concerned. However, it causes some problems in the market including port matters, etc. Therefore, it is asked to solve this problems of larger ship employed in the markets, throughout shipping alliances, etc. Conclusions - Over tonnage done by larger ship has caused some problems in the shipping markets, forming monopolistic market by small number of larger shipping companies, destroying oligopolistic nature of shipping business, therefore, the answer is strategic alliance to collaborate each other.

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.3
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• pp.102-111
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• 2017

This study considered the effects on the seabed of a harbor and quay wall from ship maneuvers in relation to the thruster jet flow and initial velocity. This study also included the engine capacity, RPM, and diameter and pitch of a ship's thruster for a required speed. The impact of a scour hole on the environment of a quay wall was investigated. Based on these results, a risk based analysis was conducted to evaluate different strategies and their consequences. There has been an increase in the loads on the bottom of a harbor during ship maneuvering. This increase is caused by the propeller loads of mooring and unmooring vessels. This indicates a greater number of arrivals and departures of vessels with larger drafts, larger thruster diameters, and larger available thruster power capacities. Another important cause could be an increase in the maneuverability of vessels from the use of bow thrusters. The increasing loads, which cause a higher jet flow above the bottom, can lead to undesirable scour holes.

• Journal of Korea Port Economic Association
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• v.21 no.1
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• pp.1-21
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• 2005

It has been more recent trends in container trade to make bogger ship from shipowners that many more parties concerned are getting involved. Well, it is natural to swift these situations if we have looked into container trade market in present time, which a lot of trade volumes has increased in world economy. Thus, supply side of shipping service needs to employ more capacity in the shipping market, then newbuilding may be compulsory options, that is deployment of larger ships. To cope with market situations as able shipowner, some alternatives can be also adopted, such as newbuilding, chartering and securing the space by strategic alliance. But whatever he does, shipowner has to keep in mind to prepare for the future. This is much more important factor considered to make investment decision in case of newbuilding and then he can make more efficient decision as well. However, there has been a little problems arisen due to larger ship employed on the trade route, which is linked with seaport, shipping companies and freight rates as well. Although shipowner decides to build new larger vessel as one of corporate strategic decision, there are many questions to be considered in advance. Therefore, in order to take more efficient decision, shipowner has to take into an account various situations surrounded, and then it can lead truly thoughtful decision making process.

• Journal of the Korean Institute of Navigation
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• v.21 no.4
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• pp.21-28
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• 1997

Along with the rapid growth of shipping and transportation , the size of a ship larger and larger. Low speed maneuverabililty of a full ship has been received a great deal of attention concerting about the navigation safety, especially in the harbour area of waterway. And, the iperation of the full ship in harbour area is one fo tehmost difficult technique. Usually highly experienced experts can make a suitable decision considering various propeller ,rudder actions and environmental conditions. The Artificial Neural Network is applied to the automatic berthing control of a ship. The teaching data are made by the berthing simulation of a ship on the computer. And, the layer neural network is used and the 'Error Back-Propagation Algorithm' is used to teach the neural network. Finally, it is shown that the berthing control is successfully done by the established neural network.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.663-666
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• 2004

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. AF is computed for each bridge component and vessel classification. The summation of AFs computed over all of the vessel classification intervals for a specific component should equal the annual frequency of collapse of the component. The designer should use judgment in developing a distribution of the vessel frequency data based on discrete groupings or categories of vessel size by DWT. In the present study the effect of vessel classification on the annual frequency of collapse in the ship collision risk assessment is investigated by illustrative numerical examples based on the vessel frequency data of the domestic harbor. The DWT interval for larger vessels has more effect on the ship collision risk. Therefore the expert judgement in determining the larger DWT interval is required because the design impact lateral resistances of bridge components depend on the ship collision risk.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.149-150
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• 2022

External forces acting on the mooring facilities include wave, wind, current, and ship's kinetic energy. In particular, the ship's kinetic energy is changing as the ship become larger, and larger carrying capacity. It was intended to analyze the berthing velocity measurement data at on tanker terminals equipped with a DAS (Docking Aid System) through statistical means and algorithms and use it as basic data for safer and more efficient pier design and pilotage.

• Bulletin of the Society of Naval Architects of Korea
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• v.19 no.4
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• pp.53-59
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• 1982

Relative bow-motions of a ship in wave are investigated by using linear theory. The relative displacement is assumed to be composed of incident wave elevation, motion response, dynamic swell-up and ship wave elevation. Radiation problem is solved by distributing sources on the hull surface and wave elevation in a uniform stream is obtained by integrating Havelock's function with centerplane source distributions. Relative displacements for I.T.T.C. S7-175 model are calculated. Dynamic swell-ups make the relative displacement larger except small heading angles. Amplitudes of relative motion on weather-side are generally larger than those on lee-side. Ship wave elevations in a uniform stream also give considerable contributions and our calculations are verified to be reasonable in comparison with experimental results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.3
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• pp.290-301
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• 2013

The docking analysis of a global ship structure is requested to evaluate its structural safety against the reaction forces at supports during docking works inside a dry dock. That problem becomes more important recently as the size of ships is getting larger and larger. The docking supports are appropriately arranged in a dock to avoid their excessive reaction forces which primarily cause the structural damages in docking a ship and, up to now, the structural safety has been assessed against the support arrangement by the finite element analysis (FEA) of a global ship structure. However, it is complicated to establish the finite element model of the ship in the current structural design environment of a shipyard and it takes over a month to finish the work. This paper investigates a simple and fast approach to carry out a ship docking analysis by a simplified grillage model and to assign the docking supports position on the model. The grillage analysis was considered from the motivation that only the reaction forces at supports are sufficient to assess their arrangement. Since the simplified grillage model of the ship cannot guarantee its accuracy quantitatively, modeling strategies are proposed to improve the accuracy. In this paper, comparisons between the proposed approach and three-dimensional FEA for typical types of ships show that the results from the present grillage model have reasonably good agreement with the FEA model. Finally, an integrated program developed for docking supports planning and its evaluation by the proposed approach is briefly described.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.5
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• pp.587-598
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• 1999

In recent years emissions of pollutants from ship sources, especially NOx and SOx, is controlled by IMO(International Maritime Organization). The emissions of pollutants from ship sources in Pusan is considerably large, because the number of ship's coming and going in Pusan port is larger than that of other ports in Korea. Since Pusan is under the strong influence of land-sea breezes, pollutants emitted from ship sources will be transported into the inland. Control of emissions from ship sources is required to devise effectively the policy of air quality management in Pusan. Therefore this paper considered the present condition of total pollutant sources and emission characteristics including in coastal urban area.

• Bulletin of the Society of Naval Architects of Korea
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• v.15 no.4
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• pp.1-5
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• 1978

The preliminary ship design step is made into a non-linear programming(NLP) problem. And using SUMT-exterior method and Hook Jeeves pattern search, the optimum ship characteristics are determined for the case where the ship is built in Korea and is operated by Koreans. Three programs for bulk carrier, tanker, and container ship are constructed and several sensitivity tests are performed. The result has little difference from the results of the other papers, but for high interest rate of return, slightly larger and faster ship is superior, and for low labour costs, slightly smaller and slower ship is superior.