• Journal of Korean Port Research
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• v.4 no.1
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• pp.3-20
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• 1990

The Port of Pusan, the largest port in Korea, handled 23% of total sea borne cargo movement, 14% of imported cargo, 58% of exported cargo and 95% of container cargo in 1989. Also the port of Pusan has been played a key role in handing container cargo throughout the last 10 years. The paper is aimed to survey the effect of sea borne cargo movement to urban transportation, that is, to find traffic volume arising by general/bulk cargoes through the port and to estimate vehicle rated of container tractor tailer on the roads between terminal including conventional piers and ODCY, and finally the following results are obtained. (1) AADV of truck to transport general/bulk cargoes are 6,322 units in 1989,and routes penetrate into the center of city and pass through the most of urban arterials. (2) In the container transport, if HVEF is adopted to 3 of tractor trailer, AVR in each transport freeway 13.7%. (3) IF HVEF is adopted to 6 of tractor trailer. AVR are as follows: BooDoo-Ro 44.1%, WooAm-Ro 39.3%, SooYoung-Ro 17.8%, Urban freeway 20.3%. Based upon these results, the following suggestions were drawn : o ODCY scattered around the city should be unified in a few groups to raise port productivity. o Rail service for inland container transportation should be escalated to relieve urban traffic congestion. o Coastal feeder service between terminal and hinterland should be studied to restrict the penetration of container tractor trailer into the central parts in the urban areas. o Exclusive freeway system for effective container transportation should be implemented to reduce urban traffic delay.

• Journal of Korea Water Resources Association
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• v.56 no.7
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• pp.431-438
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• 2023

Many shorelines are facing the beach erosion. Considering the climate change and the increment of coastal population, the erosion problem could be accelerated. To address this issue, developing a sediment transport model for rapidly predicting terrain change is crucial. In this study, a sediment transport model based on GPU parallel arithmetic was introduced, and it was supposed to simulate the terrain change well with a higher computing speed compared to the CPU based model. We also aim to investigate the model performance and the GPU computational efficiency. We applied several dam break cases to verified model, and we found that the simulated results were close to the observed results. The computational efficiency of GPU was defined by comparing operation time of CPU based model, and it showed that the GPU based model were more efficient than the CPU based model.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.41-51
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• 2013

The tidal creek dependent mass transport characteristic in Gyeong-Gi Bay (west coast of Korea) was studied using field measured data and numerical model. Gyeong-Gi Bay consists of 3 main tidal channels and contains a well-developed vast tidal flat. This region is famous for its large tidal difference and strong current. We aim to study the effect of tidal creek in the tidal flat on the mass exchange between the estuary and the ocean. For numerical application, the application of unstructured grid feature is essential, since the tidal creek has complicated shape and form. For this purpose, the FVCOM is applied to the study area and simulation is performed for 2 different cases. In case A, geographic characteristics of the tidal creek is ignored in the numerical grid and in case B, the tidal creek are constructed using unstructured grid. And these 2 cases are compared with the field measured cross-channel mass transport data. The cross-channel mass transport at the Yeomha waterway mouth and Incheon harbor was measured in June, 9~10 (Spring tide) and 17~18 (Neap tide), 2009. CTD casting and ADCP cross-channel transect was conducted 13 times in one tidal cycle. The observation data analysis results showed that mass transport has characteristic of the ebb dominance Line 1 (Yeomha waterway mouth), on the other hand, a flood dominant characteristic is shown in Line 2 (Incheon harbor front). By comparing the numerical model (case A & B) with observation data, we found that the case B results show much better agreement with measurement data than case A. It is showed that the geographic feature of tidal creek should be considered in grid design of numerical model in order to understand the mass transport characteristics over large tidal flat area.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.4
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• pp.257-268
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• 2012

The EFDC model with find grid resolution system connecting the Gyeong-Gi bay and Han River estuary was constructed to study on spring-neap variability of net volume transport at each channel of the Han River estuary. The simulation time of numerical model is 124 days from May to August, 2009 with freshwater discharge at Han, Imjin and Yeseong River. The calibration and verification of model results was confirmed using harmonic components of water level and tidal current. The net volume transport was calculated during 30 days with normal freshwater conditions at Seokmo channel and Yeomha channel around Ganghwado. The ebbing net volume transport of 44% and 56% is drained into Gyeong-Gi bay through Yeomha and Seokmo channel, respectively. The ebbing net volume transport nearby Seodo at Yeomha channel convergence flooding net volume transport at Incheon harbor, and drain (westward direction) through channel of tidal flat between Ganghwado and Yeongjongdo to the Gyeong-Gi bay. The averaged net volume transport during 4 tidal cycles was compared to variation of spring-neap periods of the Yeomha channel. The convergence position is moved up- and down-ward according to spring-neap variability. The movement of the convergence zone is appeared because 1) increasing of discharged rate tidal flat channel between Ganghwado and Yeongjongdo at the spring period, 2) The growth of barotropic forcing with downward direction at the spring tide, and 3) The strength of the baroclinic pressure gradient is greater than spring with mixing processes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.4
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• pp.228-237
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• 2015

Field observations were conducted to collect hydrodynamic and morphological data, which are needed to account for mechanisms of bathymetry changes caused by physical forcings, in Haeundae beach. In order to quantitatively describe characteristics of wave transformations and current patterns in space in winter and summer, in-situ sensors for measuring waves and current profiles were installed at three locations in the cross-shore direction and also three locations in the along-shore direction. As for the results of wave measurements, waves with main direction from the east dominate in winter while waves are incident from the S and the ESE in summer. Analysis of current data reveals that currents over the study domain are considerably influenced by a pattern of tidal motions, thereby, mainly oscillating in the direction of tidal currents, i.e., east-west directions, in both winter and summer. Currents tend to be influenced by local bathymetry in the shallow water region, with the direction changed along the depth contours and the magnitude reduced as they approach the shoreline. The results analysed from the hydrodynamic data through this study can be further combined with the morphological and bathymetry data, leading to the quantification of seasonal sediment transport rates and sand budget changes.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.1
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• pp.13-23
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• 2008

In coastal region, eutrophication, Do deficit and red tide are frequently occurred by influx of fresh water. When the fresh water containing pollutants is discharged into the sea, the surrounding water is contaminated by dispersion of freshwater flowing into coastal waters. The prediction and analysis about the dispersion process of the discharged fresh water should be conducted. A modeling system using GUI was developed to simulate hydrodynamic flow and fresh water dispersion in coastal waters and to analyze the results efficiently. The modeling module of the system includes a tide model using a finite element method and a fresh water dispersion model using a particle-tracking method. This system was applied to predict the tidal currents and fresh water dispersion in Mokpo coastal zone. To verify accuracy of the hydrodynamic model, the simulation results were compared with observed sea level and time variations of tidal currents showing a good agreement. The fresh water dispersion was verified with observed salinity distribution. The dispersion model also was verified with analytic solutions with advection-diffusion problems in 1-dimensional and 2-dimensional simple domain. The system is operated on GUI environment, to ease the model handling such as inputting data and displaying results. Therefore, anyone can use the system conveniently and observe easily and accurately the simulation results by using graphic functions included in the system. This system can be used widely to decrease the environmental disaster induced by inflow of fresh water into coastal waters.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.1
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• pp.54-64
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• 1991

To accurately estimate the rate of sediment transport in shallow water bodies, it is necessary to investigate the irregular waves transformation characteristics and nearshore currents produced by random sea waves. Most of studies on numerical models for nearshore currents are based on the theory of monocromatic waves and thus, very few nearshore models take into account the effect of irregularities in the hight, period and directional spreading of incident waves. The numerical simulation model for nearshore currents used in this paper considers the effect of irregularities of incident waves, based on Individual Wave Analysis. The computational results are compared and shown in a reasionable agreement with the experimental data.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.4
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• pp.209-216
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• 1991

Characteristics of suspended sediment concentration of equilibrium and non-equilibrium state caused by waves and currents are investigated by conducting a movable bed experiments in wave tanks. In the region where a downward flux of suspended sediment is larger than a upward flux, time-averaged vertical distribution of suspended sediment does not indicate logarithmic distribution. A new numerical procedure for predicting time-averaged suspended sediment concentration is also proposed based on two-dimensional advective diffusion equation by applying a split-operator approach. It is found that the unposed procedure can predict measured distribution of suspended sediment satisfactorily.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.2
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• pp.81-91
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• 1991

A k-$\varepsilon$ equation model was established to investigate the behaviours of two-dimensional surface buoyant jets. Its computational results were compared with experimental data on the mean flow and the turbulent transport. The model was proved to predict the flow characteristics reasonably. The influence of the values of k and $\varepsilon$ given in the inlet on the evaluation of surface buoyant jets was examined to determine them quantitatively. Computations for several values of buoyancy production coefficient $C\varepsilon$$_3$ in the $\varepsilon$ equation, which has been neglected by many researchers. were carried out to evaluate its effect on the flow development. Computational results of the two-dimensional surface buoyant jets were presented and briefly discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.2
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• pp.108-115
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• 1991

This paper aims at the elucidation of the characteristics of longshore current profile after wave breaking. Wave breakers are always accompanied by complex turbulent process, wave energy losess occur and the mean water level also varies due to the gradient of radiation stress. These with other factors result in the development of longshore currents. Longshore currents have relations to the alongshore sand transport and to the diffusion of contaminants in nearshore region, thus the understanding and elucidation of them are very important from the engineering point of view. Using the calculated results, the factors such as lateral mixing cofficients, bed shear stress. wave angle. wave steepness and bottom slope. which are influencing the longshore current profile. are examined. Also, by comparing the results of longshore currents with the experimental data obtained by other investigators, the procedure proposed in the present study is shown to be valid.