• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.16 no.2
• /
• pp.57-63
• /
• 2004

Wave lengths of tsunamis are shorter than those of tides, and the dispersion effect of tsunamis is relatively strong. Thus, it should be properly considered in the numerical simulation of distant tsunami propagation for better accuracy. In the present study an active dispersion-correction scheme using explicit scheme is developed to take into account the dispersion effect in the simulation of tsunami propagation using one-dimensional finite element method based on wave equation. The validity of the dispersion-correction scheme proposed in this study is confirmed through the comparision of numerical solutions calculated using the present scheme with analytical ones considering dispersion effect of waves.

• Journal of Navigation and Port Research
• /
• v.27 no.5
• /
• pp.539-546
• /
• 2003

The numerical model of the flow analysis by finite element technique is described. The Galerkin method is employed for spatial discretization Two step explicit finite element scheme is used to discretize the time function, which has advantage in problems treating large numbers of elements and unsteady state. Two dimensional hydrodynamic model considering moving boundary condition is developed. Also it applied flow model which develop on flow portion of ideal fluid in the model flume and verified, and the results of this study confirm the efficiency of moving boundary treatment in Jeju harbor. The computed results have shown the good adaptability of moving boundary condition From these studies, it can be concluded that the present method is a useful and effective tool in tidal flow analysis.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.15 no.2
• /
• pp.108-115
• /
• 2003

Two types of one-dimensional dispersion-correction scheme are developed to take into account the dispersion effects for the simulation of tsunami propagation using ADCIRC finite element model based on shallow-water equations The first is an implicit scheme, and the dispersion-correction is accomplished by controlling the weighting factor assigned to each spatial derivative term of different time levels. The other scheme is explicit and the dispersion is considered by adjusting the element size. The validity of the dispersion-correction scheme proposed in this study is confirmed through the comparison of numerical solutions calculated using the new schemes with analytical ones considering dispersion effect of waves.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.8 no.1
• /
• pp.103-113
• /
• 1996

Two-dimensional finite element hydrodynamic models for long wave simulation usually adopt fixed land boundary. However moving boundary treatment is strongly required in the simulation of tidal flats for west and south coast of Korea. In this study very efficient and realistic moving boundary treatment is applied by considering incident long wave surface slope. Developed STEP-CM (Superior Two-step Explicit Program for Coastal Modeling) ,shows numerically stable results in comparative study for idealized one-dimensional channel. Real application of the model is done for Chonsu Bay where tidal flats are distributed along the coast. Nonlinear tidal current and tidal flat effects are easily simulated in STEP-CM and resulting circulations are detected around headland of Wonsan Island.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.10 no.4
• /
• pp.141-150
• /
• 1990

Numerical experiments of sballow water equations are performed under various boundary conditions by finite element method to simulate the circulation in estuaries and coastal areas. Galerkin method is employed to discretize spatial domain, and for time integration, finite difference method (Crank-Nicolson scheme) is used. This method is tested in five problems, in which first four cases have analytic solutions. The computed values are well in agreement with the analytic solutions in four experiments and the result of the last 2-dimensional ease is resonable. Implicit and two step Lax-Wendroff schemes in time domain are compared, and the results when using four node bilinear and triangular elements are presented. Consequently it takes very long time for complex problems requiring many elements to integrate all the time steps using the implicit schemes. And the explicit scheme requires careful consideration in selecting the time step and the grid size to obtain the desired accuracy.

• Journal of the Society of Naval Architects of Korea
• /
• v.31 no.1
• /
• pp.94-101
• /
• 1994

This paper describes a short-term prediction model for the movement of an oil slick in shallow waters. Under the assumption that the initial movement of the oil slick is governed by spreading and advection, the model has been developed and applied to Kyungki-Bay near Incheon Harbor. The initial spreading is estimated by using an empirical formula. The depth-averaged momentum equations are solved numerically for the volume transport velocities, in which the $M_2$ tide is the main driving source. A staggered grid system is adopted fur spatial discretization and the half-time method is implemented for time marching. The numerical result is visualized with the help of animation and thus the contaminated area is displayed on a monitor in time sequence. The input data are the time, the location and the volume of spill accident as well as environmental data such as md and $M_2$ tide.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.2 no.2
• /
• pp.20-30
• /
• 1999

To improve water quality particularly for sea bathers along the Fylde coastal zone near Blackpool, North West England, waste water from a sewage outfall is studied using a mathematical model. The explicit second order accurate central scheme and the third order accurate QUICKEST scheme are used to represent the diffusion terms and the advection terms of the advective-diffusion equation, respectively. Hydrodynamic model is run for a coarse and fine grid, of 1km and 200m, respectively, obtaining good agreement with measured data. Water quality model is then used to predict faecal coliform levels in the region for four different scenarios, including discharges from: - (i) Fleetwood outfall, (ii)River Ribble for summer condition, (iii)River Ribble for winter condition, and (iv)combined sewer overflows for the Blackpool and Fleetwood communities. Main findings from the simulations are:- (i) Fleetwood outfall has a negligible impact on the beaches with respect to pathogen levels; (ii) Discharge from River Ribble for both summer and winter conditions is predicted in the range of coliform levels 10 -500 counts/100ml along the beach at Lytham St. Annes; and (iii) The CSO effluent discharges are predicted not to advect out into offshore by stronger tidal currents.

• Journal of Legislation Research
• /
• no.53
• /
• pp.419-454
• /
• 2017

Faced with the internationalization of capital markets, Korea needs to protect its investors and markets by applying the relevant laws extraterritorially. The Financial Investment Services and Capital Markets Act ("Capital Markets Act") explicitly introduced a new provision recognizing the extraterritoriality of the Act. While Article 2 of the Capital Markets Act comprehensively provides for prescriptive extraterritorial jurisdiction, the enactment of extraterritoriality alone does not guarantee that the Act will apply to cross-border transactions effectively. The effective extraterritorial application of an act is inseparable from the adjudicative and enforcement jurisdiction of the act. Specifically, active investigations and detections by the public regulators might be the first step for enforcing the Capital Markets Act. Unlike domestic regulations, however, multinational enforcement actions outside a regulator's home country becomes more problematic because of various obstacles. This Article examines difficulties which domestic regulators may confront in enforcing the Capital Markets Act extraterritorially and makes several recommendations for more effective multinational enforcement as follows. First, the Korean regulators should continue to foster cooperation through the IOSCO and provide international markets with the information and tools necessary for successful regulation of cross-border transactions. Second, the principle of dual criminality should be applied in a modified form for the effective mutual legal assistance in criminal matters. Third, there should be a legal device for the domestic regulator to freeze foreign wrongdoer's assets located outside Korea to repatriate those assets for distribution to defrauded investors in Korea.