• Journal of the Korean Society of Marine Environment & Safety
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• v.6 no.1
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• pp.77-83
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• 2000

En coastal area, many submarine facilities such as pipes and cables are installed on/under the sea bed. Also, there are heavy traffic due to numerous vessels which call in ports or navigate passages in adjacent water. Therefore, the frequency of dropping anchors will be increased to avoid various dangerous situations. When an anchor is dropped from vessel on the sea bed, the anchor strikes on the sea bed, and then, the anchor penetrates to certain depth into the sea bed. In this case, sometimes submarine facilities on/under the sea bed may be damaged by the strike or the maximum penetrating depth of anchor. In this paper, some approximate equations on the strike and the penetrating depth of anchors have been derived on the basis of actual data, and the results are expected to use as basic design data of related facilities.

• Journal of Ocean Engineering and Technology
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• v.17 no.2
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• pp.8-13
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• 2003

Soil, ground water, and sea bed are exposed to a continuous accumulation of polluted materials, causing serious environmental damage. It has been reported that such pollution causes a massive mortality of fish stock in rivers due to the resuspension of toxic chemicals, occurring during strong wind conditions. Therefore, it becomes apparent that there is an immediate demand for the restoration treatment of polluted river bed (or sea bed) sediment layers. Pollution levels of major rivers and ports, such as Paldang, Kyungan rivers, and Masan port, are becoming of great public concern, and are posing a serious environmental threat. In particular, the pollution of the Shi-hwa river has become a nation wide issue for the last few years. In spite of such public concern, the pollution levels of such rivers or ports are worsening everyday. In this study, an environmentally sound engineering package is introduced that helps to restore the polluted river bed or sea bed sediments. This engineering package consists of a suction facility, followed by a series of mechanical, chemical, and biological treatment units. The suction facility is designed to minimize secondary pollution that occurs from the resuspension of toxic materials during suction. The sea bed cleaning engineering package is designed to be installed on the top of a floating barge. Such a combination of environmental plant and shipbuilding technology provides a cost-effective solution, minimizing the transportation between suction and treatment facilities.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.178-188
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• 2003

A study on the dynamic analysis of a tracked vehicle for mining on deep-sea bed with very soft soil is presented. An equation for the interaction between track and soft soil is employed to develop a track/soil interaction module called TVAS. The vehicle is modeled as a multi-body dynamic system using a multi-body dynamic analysis program. The developed module is incorporated into the multi-body dynamic analysis program with a user subroutine. The dynamic behavior and design of the mining vehicle on deep-sea bed is investigated.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.484-492
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• 2015

The purpose of this study is to compare the ichthyofauna between the eelgrass bed waters located in the open sea and the nearby sea free of eelgrass, and this study collected a total of 26 species. Comparing the fish collected on the eelgrass bed (St.2) of Geomun-do coast with the fish collected on the coastal waters (St.1) void of the nearby eelgrass bed, the fish collected from the eelgrass bed included 19 species, 413 individual with 16,110.6g in weight while the fish collected from the coastal waters void of the eelgrass bed included 19 species, 290 individuals with 12,961.5g in weight. Accordingly, it was found that the population size and biomass of the fish collected from the eelgrass bed were higher than the coastal waters void of the eelgrass. This study could identify that diversity, richness, evenness index except dominance were also much higher even in the result of cluster analysis.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.161-166
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• 2004

Research for deposits in Nakdong eatuary that research about Nakdong eatuary's sediment flows out in Nakdong-kang so far had been progressed but research about deposits that is flowed in open sea is insufficient. Observed Nakdong eatuary's characteristic of sediment transfer through observation during the second during Buteo 20 days on February 6, 2004 in this research Resuspension bed load Flux appeared high the first result St.4 point and St.5 point. St.4 branch had much bed load amount that is flowed in the east, and bed load that St.5 branch is flowed in the south appeared much Tendency such as the first showed in the second result, but compare with the first result and St.5 branch had much bed load that is transfer in end. Bed load that is transfer in observation result Nakdong river was less. As this, can know that amount of sediment that is transfer in open sea more than deposits that is transfer in Nakdong river is much Is expected to exert effect that deposits that is transfer in open sea is high in Nakdong estuary's topography change. Specially, observation result is expected that Nakdong estuary's deposition tendency becomes Jinwoodo southern and Shinho southern.

• Ocean and Polar Research
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• v.30 no.3
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• pp.239-247
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• 2008

Spatial distribution of water flow generated by tidal current was investigated within a Zostera marina(seagrass) bed in Wonpo Bay. Water flow and elevation were observed during the seagrass growing season. The spatial distribution of water flow was numerically estimated using roughness coefficient. Water flow inside the seagrass meadow was compared with the observed values. Velocity in Zostera marina vegetated areas was approximately $25{\sim}84%$ lower than that of unvegetated areas. However, flow direction was the same. Intensity of the flood tide diminished appreciably within the seagrass bed, while its pattern was also affected. It is therefore concluded that water flow is influenced by Zostera marina meadows.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.5
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• pp.364-371
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• 2015

This study is aimed to develop the dynamic analysis technique for a floating aquaculture in a shallow water region under the harsh sea condition. In case of the installation region to transform from a coastal area to the offshore area, the influence of sea bed with sea waves on the mooring lines was announced to be significant by other authors. In this study, the numerical tool was developed to solve dynamic behavior of the floating barge coupled with mooring lines in a shallow zone of the sea considering the influence of sea bed on the floating system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.12-16
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• 2002

Soil, ground water and sea bed are exposed to continuous accumulation of polluted materials causing serious environmental damage. It has been reported that such pollution causes a massive mortality of fish stock in rivers by the resuspension of toxic chemicals during strong wind conditions. Therefore, it becomes apparent that there is an immediate demand for the restoration treatment of polluted river bed (or sea bed) sediment layers. Pollution levels of major rivers and ports such as Pal-dang, Kyung-an rivers, Ma-san port are becoming public concern and are posing a serious environmental threat. In particular, the pollution of Shi-hwa river has become a nation wide issue for last few years. In spite of such public concern, the pollution level of such rivers or port are getting worse everyday. In this study, an environmentally sound engineering package is introduced which helps to restore the polluted river bed or sea bed sediments. This engineering package is consisted of a suction facility followed by a series of mechanical, chemical as well as biological treatment units. The suction facility is designed to minimize the secondary pollution due to the resuspension of toxic materials during suction. The sea bed cleaning engineering package is designed to be installed on the top of a floating barge. Such combination of environmental plant and shipbuilding technology provides a cost-effective solution, minimizing the cost involved in the transportation between suction and treatment facilities.

• Journal of Ship and Ocean Technology
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• v.1 no.1
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• pp.35-47
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• 1997

The consequences associated with ships running aground depend very much on the soil characteristics of the sea bed and the geometrical shape of the ship bow. The penetration into the sea bed depends on these factors and the penetration is an important factor for the ship motion because it influences the ship heave and pitch motions as well as the friction between the ship and the soil. In this paper a rational calculation model is presented for the sea bed soil reaction forces on the ship bottom. The model is based on the assumption that the penetration of the ship bow generates a flow of pore water through the grain skeleton of the soil. The flow is governed by Darcy\`s law and it is driven by the pressure of the pore water at the bow. In addition to this pore water pressure, the bow is subjected to the effective stresses in the grain skeleton at the bow surface. These stresses are determined by the theory of frictional soils in rupture. Frictional stresses on the bow surface are assumed to be related to the normal pressure by a simple Coulomb relation. The total soil reaction as a function of velocity and penetration is found by integration of normal pressure and frictional stresses over the surface of the bow. The analysis procedure is implemented in a computer program for time domain rigid body analysis of ships running aground and it is verified in the paper through a comparison of calculated stopping lengths, effective coefficients of friction, and sea bed penetrations with corresponding experimental results obtained by model tests as well as large, scale tests.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.441-448
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• 2010

This paper was concentrated on the distribution and the composition of lost fishing gear on the sea bed around yellow croaker fishing ground in the near sea of Jeju, Korea from April to October 2009 in order to improve the fishery environment. Recovering lost fishing gears was carried out total 10 times with a trawlnet along the isobath. As the result, it seems reasonable to conclude that the amount of lost fishing gear has a deep connection with the dip of the sea bed as well as the fishing gear scale, fishing ground and so on. The amount of recovered lost fishing gears were in order of gillnets, dragged gears, traps and ropes. In particular, traps were recovered almost every time within the survey area.