• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 1994.07a
• /
• pp.74-77
• /
• 1994

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 1994.07a
• /
• pp.81-83
• /
• 1994

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 1994.07a
• /
• pp.116-120
• /
• 1994

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.5 no.4
• /
• pp.369-383
• /
• 1993

An amended form of radiation stress is presented in the present model and the existence of the surface advection terms is verified through comparisons with wave energy equation. The model yields circulation patterns in both cross-shore and longshore directions on the plane beach slope. Comparison with laboratory experiments showed good agreements. Finally, a quasi-three dimensional model suitable for the entire nearshore zone is developed by linking the depth-integrated properties with vertical profiles.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 2000.09a
• /
• pp.1-23
• /
• 2000

This paper discusses the development of design methods for coastal structures and breakwaters in the United Kingdom, with particular attention to changes in research activities, publications, technology transfer and the use of research results over the last 200 years. The paper describes some examples of the design and construction of breakwaters and seawalls, methods by which their designs and construction techniques were improved, and how those improvements were promulgated within civil engineering. It discusses problems that arise from recent trends in research funding and publication, and seeks to indicate some possibilities for the future. The paper draws on the author's experience in research and specialist consultancy at HR Wallingford, published papers and books, but is also guided by lessons from related work in UK and elsewhere.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.1030-1032
• /
• 2003

This study a imed to analyze the effect of combined optical and radar image for the land cover classification in coastal region. The study area, Gyeonggi Bay area has one of the largest tidal ranges and has frequent land cover changes due to the several reclamations and rather intensive land uses. Ten land cover types were classified using several datasets of combining Landsat ETM+ and RADARSAT imagery. The synergic effects of the merged datasets were analyzed by both visual interpretation and an ordinary supervised classification. The merged optical and SAR datasets provided better discrimination among the land cover classes in the coastal area. The overall classification accuracy of merged datasets was improved to 86.5% as compared to 78% accuracy of using ETM+ only.

• Journal of Radiation Industry
• /
• v.7 no.2_3
• /
• pp.201-207
• /
• 2013

Soil liquefaction by tsunami or wave induced currents can cause serious damages to coastlines and coastal infrastructures. Although liquefaction caused by regular waves over sea beds has been extensively investigated, studies of tsunami-induced liquefaction near coastal area have been relatively rare. In this work, the hydraulic scale model has been designed and constructed to investigate the variations of wave height and sediment transport by tsunami. The distorted hydraulic scale model based on the Froude similarity was adopted to represent hydrodynamics and sediment transport in a coastal area. The scale model was composed of control box, screw axis, wave paddle and rotating coastal structure.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.21 no.3
• /
• pp.230-240
• /
• 2009

The ESCORT model is applied at Mokpo coastal zone to analyze the effect of fresh water discharge released from the gates of the Youngsan River sea-dyke. Applicability and validity of both 2-D and 3-D hydrodynamic modules could be guaranteed by simulating hydrodynamic feature with ebb dominance characteristics. Then, effects of the released discharge on the hydrodynamics are investigated. And analysis of the effects on diffusion phenomena show that 3-D model is essential for such diffusion modelling. Moreover, vertical salinity distributions near the gates are examined, and the influence range of fresh water is also estimated, which shows that dilution of fresh water is going on slowly because of poor flushing.

• Journal of the Society of Naval Architects of Korea
• /
• v.48 no.2
• /
• pp.158-164
• /
• 2011

The study on the improvement of resistance performance is very important for coastal fishing boats in Korea, because the prices of fuel oil are gradually risen and the demand of high-speed fishing boats is increased lately. This study is concerned with the improvement of the resistance performance for Korean high-speed small coastal fishing boats. A semi-planing hull form of Korean small coastal fishing boat is selected in the role of initial hull. From the modification of the hull form parameters and the local characteristics of the hull form, the improvement of the resistance performance is achieved. The resistance performances of the initial and the modified hull forms are estimated by using a numerical simulation method. Also, ship model tests are carried out in ship model basin.

• Structural Engineering and Mechanics
• /
• v.81 no.2
• /
• pp.179-194
• /
• 2022

The bending, buckling and free vibration responses of functionally graded material (FGM) beams are investigated semi-analytically by the scaled boundary finite element method (SBFEM) in this paper. In the concepts of the SBFEM, the dimension of computational domain can be reduced by one, therefore only the axial dimension of the beam is discretized using the higher order spectral element, which reduces the amount of calculation and greatly improves the calculation efficiency. The governing equation of FGM beams is derived in detail by the means of the principle of virtual work. Compared with the higher-order beam theory, fewer parameters and simpler control equations are used. And the governing equation is transformed into a first-order ordinary differential equation by introducing intermediate variables. Analytical solutions of the governing equation can be obtained by pade series expansion in the direction of thickness. Numerical example are compared with the numerical solutions provided by the previous researchers to verify the accuracy and applicability of the proposed method. The results show that the proposed formulations can quickly converge to the reference solutions by increasing the order of higher order spectral elements, and high accuracy can be achieved by using a small number of the elements. In addition, the influence of the structural sizes, material properties and boundary conditions on the mechanical behaviors of FG beams subjected to different load types is discussed.