• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.613-616
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• 2007

The main structures that comprise a tidal power plant are turbine structure, sluice structure, tide embankment and gate. Since these structures are founded on seabed ground, an extensive geotechnical site investigation to evaluate the engineering properties of field soils must be conducted prior to design and construction. According to the results of geotechnical site investigation conducted at the planned site for construction of Incheon bay tidal power plant, soft ground generally lie 7 meters below the seabed surface level. This research suggests the reliable and economical design of foundations and ground improvements required for construction of main structures in Incheon bay tidal power plant, with considerations on field conditions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.416-422
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• 2009

Offshore wind turbine are subjected to more various loads than general land structures and the stability of structures is supported by the piles driven deeply in the subsoil. So it is more important for offshore structures to consider seabed soil-structure interaction than land structures. And the response of a fixed offshore structure supported by pile foundations is affected by resist dynamics lateral loading due to wave forces and ocean environmental loads. In this study, offshore wind tower response are calculated in the time domain using a finite element package(ANSYS 11.0). Several parameters affecting the vibration characteristics of the natural frequency and mode shape and the tower response have been investigated.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.10
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• pp.581-586
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• 2005

The multi-beam side scan sonar system uses the towfish installed sonars, it is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. Recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. Therefore, this research develops multi-beam sensors for a side scan sonar that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.201-204
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• 2006

In the side scan sonar method, use is made of the back-scattering, at low grazing angles of incidence to the seabed, of relatively high-frequency acoustic waves radiated in a fan-shaped beam from a transducer contained in a towed body. The fan beam is oriented so that the wider angle is in the vertical plane (scan range) and the narrower angle in the horizontal plane (beam width) with the axis of the beam normal to the ship track. The display of the returns is usually realized as a series of closely spaced intensity-modulated lines on a paper recorder or computer screen display. In this way a two-dimensional picture of the seabed is build up.

• 보존과학연구
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• s.27
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• pp.63-82
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• 2006

We conducted species identification on the wooden materials of 10 pieces and grasses which come out from the seabed relics in Sibidongpado, Gunsan. This site is presumed to date from the Goryeo's relics. Species identification show that pieces of ship are pinus(4 pieces), ulmus(1 piece), platcarya(1 piece). Lepidobalanus(2 pieces), platcarya(2 pieces) came out from the others. Grasses are located between ceramics that were piled up. Grasses are supposed to be Phragmites Trin.

• Ocean Systems Engineering
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• v.5 no.1
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• pp.31-40
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• 2015

Three dimensional (3D) non-linear finite element analysis of offshore pipeline is investigated in this work with the help of general purpose software Abaqus. The general algorithm for the finite element approach is introduced. The 3D seabed mesh, limited to a corridor along the pipeline, is extracted from survey data via Fledermous software. Moreover soil bearing capacity and coefficient of frictions, obtained from the field survey report, and are introduced into the finite element model through the interaction module. For a case of study, a 32inch pipeline with API 5L X65 material grade subjected to high pressure and high temperature loading is investigated in more details.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.43-50
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• 2007

A range-frequency interference pattern is analyzed in the course of the propagation of ship noise in shallow water. It has been shown to exhibit striated bands of intensity maxima and minima in the spectrogram. The slope of the striations is an invariant of the modal interference and is described by a waveguide invariant parameter $\beta$. It turns out that this interference pattern is useful for identifying the physical properties of the waveguide such as seabed properties. In this article, the interference pattern is analyzed using image processing techniques to produce the distribution of the beta and the effects of sediment types and geoacoustic parameters on beta distribution are examined and characterized by moments of the distributions.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.687-698
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• 2021

We present quantitative estimations of changes in the areal extent of coral reef habitats at Weno Island, Micronesia, using high-spatial-resolution remote sensing images and field observations. Coral reef habitat maps were generated from Kompsat-2 satellite images for September 2008 and September 2010, yielding classifications with 78.6% and 72.4% accuracy, respectively, which is a relatively high level of agreement. The difference between the number of pixels occupied by each seabed type was calculated, revealing that the areal extent of living corals decreased by 8.2 percentage points between 2008 and 2010. This result is consistent with a comparison of the seabed types determined by field observations. This study can be used as a basis for remediation planning to diminish the impact of changes in coral reefs.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.124.2-124.2
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• 2009

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.279-279
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• 2017