• Journal of Navigation and Port Research
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• v.30 no.2
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• pp.125-130
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• 2006

Waves, which are the main source of ship motions in a seaway, considerably affect the performance of a ship. The study of waves and their impact on ship motions within harbors is an important aspect of the design and operation of harbors. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor. Such a prediction makes it possible to evaluate ship safety more accurately. The wave transformation model reported here is applied to actual ports based on Boussinesq wave equations both non-linear and dispersive wave processes be considered in order to capture physical effects such as wave shoaling, refractions, reflection and diffraction in variable depth environments. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor, Such a prediction makes it possible to evaluate ship safety more accurately and provide safe wave informations for navigation. Furthermore, a wave information support system is proposed for entering ships as one technique for improving the safety of ship operations. This system predicts the run of waves and reduces the danger by identifying the most dangerous point near the harbor entrance at the small wave groups.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.629-636
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• 2010

A Mobile Harbor is a new transportation platform which can load and unload has containers to and from very large container ships on the sea. Currently designed Mobile Harbor a catamaran type which is equipped with precisely controlled gantry crane on the deck, and can transport 250 TEUs at a time. Loading and unloading works by crane require very small motion of Mobile Harbor in waves, because it may be operated outside of harbors. In this project, applicability of both tuned-type anti-rolling tank and maglev-type active mass driver is studied as anti-rolling systems.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.479-486
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• 2003

The concept of “Environmental Stress(ES)” can be used as a useful index when assessing the maritime traffic safety. It is composed of two parts, one due to geographical restriction and another one due to traffic congestion. In this paper, Environmental Stress due to geographical restriction is reviewed Its characteristics are surveyed from the sample calculation results for some hypothetical cases, such as approaching a breakwater, navigating in a long straight channel, and in a long bended channel. Sample calculations are also carried out for the approach channels in Busan and Kwangyang harbor. By using this ES concept, it is expected that objective ana quantitative assessment of safety is possible for various environmental conditions when navigating in a harbor or in a fairway.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.198-205
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• 2003

The concept “Environmental Stress(ES)” can be used as a useful index when assessing the maritime traffic safety. It is composed of two parts, one due to geographical restriction and another one due to traffic congestion. In this paper, Environmental Stress due to geographical restriction is reviewed. Its characteristics are surveyed from the sample calculation results for some hypothetical cases, such as approaching a breakwater, navigating in a long straight channel, and in a long bended channel. Sample calculations are also carried out for the approach channels in Busan and Kwangyang harbor. By using this ES concept. it is expected that objective and quantitative assessment of safety is possible for various environmental conditions when navigating in a harbor or in a fairway.

• Computational Structural Engineering
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• v.27 no.2
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• pp.47-54
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• 2014

• Proceedings of the Korea Water Resources Association Conference
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• 2003.05b
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• pp.1019-1022
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• 2003

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.29-41
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• 2005

The small harbors and fishing ports in Korea have less economic efficiency if the previous construction method of breakwater would be utilized due to bad ground conditions in spite of low design waves. Therefore, it is necessary to develop a new type breakwater economically applicable to the cases with low design wave. In this study, a soldier pile type breakwater, which is found to be economic and can be easily constructed on the ground without any need of treatment of the ground, was newly introduced. The effects of embedded depth, reinforcement methods as well as pile types including saw type and flat type on the lateral behavior of the proposed breakwaters installed in loose sandy soils were investigated from model test. The test results revealed that the lateral resistance increases by increasing the embedded depth and by adopting the reinforcement techniques such as raker and anchor. Furthermore, it was also verified that the saw type breakwater shows better geotechnical performance than the flat type breakwater.

• Journal of Navigation and Port Research
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• v.34 no.4
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• pp.271-279
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• 2010

The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH's roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices' dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH's six DOF dynamics and the ART's and AMD's control variables. In order to conveniently include the ART's and AMD's control dynamics in the time domain, MH's radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.533-539
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• 2006

Today the harbor oscillation problems are the most significant factor to design harbors serving the very large ships. Large vessels moored in the elastic hawsers at the coastal harbors are often displaced due to the resonance between the long period waves and mooring system. The cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes remarkable. The most significant harbor which is confronted with harbor oscillation problem in Korea is the Pohang New Port. Many cases of problems are being notified by the pilot association and local office of MOMAF. However, it is difficult to prevent the arrival of long waves musing oscillation within this harbor. Moreover, government already started new port plan at the mouth of Yeongil Bay without treating problems occurred in the Pohang New Port. This study deals with the variation of harbor oscillation due to the construction of 4.1km breakwater at the bay mouth and new port plan. Numerical method used are fairly standard form from the extended mild slope equation The obtained numerical results were compared with the field measurement from the previous study and this will bring a certain level of discussion and consideration of variation in the future port development.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.199-206
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• 2006

Today the harbor oscillation problems are the most significant factor to design harbors serving the very large ships. Large vessels moored in the elastic hawsers at the coastal harbors are often displaced due to the resonance between the long period waves and mooring system. The cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes remarkable. The most significant harbor which is confronted with harbor oscillation problem in Korea is the Pohang New Port. Many cases of problems are being notified by the pilot association and local office of MOMAF. However, it is difficult to prevent the arrival of long waves causing oscillation within this harbor. Moreover, Government already started new port plan at the mouth of YoungIl Bay without treating problems occurred in the Pohang New Port. This study deals with the variation of harbor oscillation due to the construction of 4.1km breakwater at the bay mouth and new port plan. Numerical method used are fairly standard form from the extended mild slope equation. The obtained numerical results were compared with the field measurement from the previous study and this will bring a certain level of discussion and consideration of variation in the future port development.