Hyoseob Kim

• Kookmin University

Coastal bed profile change is described by bed load, pick-up, and settling on a boundary-fitted moving grid. Existing bed load formula is modified by changing threshold bed shear stress to reflect local bed slope. A numerical model system adopting the above function is developed to simulate cross-shore sediment transport around swash zone with stee...

Strong wave-induced currents frequently develop at Haeundae Beach, Korea. Rip currents at the beach have threatened safety of swimmers in water. Near-shore currents at Haeundae Beach during a high wave time were measured on 4 June 2008 by using drogues equipped with GPS. The current field during measurement period showed westward flow along shoreli...

Kim, H.; Jin, J.Y.; Jang, C.; Yoo, H.J., and Hwang, D.H., 2014. Simulation of seasonal bathymetric change at Haeundae Beach with two representative wave settings. Long-term shoreline position of Haeundae Beach has been quite stable notwithstanding seasonal oscillatory movement. Bathymetry around Haeundae Beach was surveyed on 7 August 2007 and 12 N...

Submerged thin walls are extreme case of submerged rectangular blocks, and could be used for many purposes in rivers or coastal zones, e.g. to tsunami. To understand flow characteristics including flow and pressure fields around a specific submerged thin wall a numerical model was applied which includes computation of hydrodynamic pressure on {\sig...

Vertical diffusivity of suspended sediment with wide size distribution is concerned. The sediment size is expressed by ϕ scale, and the ϕ values are assumed to be normally distributed. The suspended sediment concentration is divided into two groups, 2% of fine side, and 98% of the rest, and single representative settling velocity for median size is...

An algorithm to allow shoreline movement during numerical experiment on sediment transport, deposition or resuspension for general coastal morphology is proposed here. The bed slope near shoreline, i.e. mean sea level, is influenced by bed material, tidal current, waves, and wave-induced current, but has been reported to remain within a stable rang...

The Leibniz integral rule for the first derivative with variable limits of integration is expanded for the second and the third order derivatives by using the chain rule here. Water wave propagation equation in the x-z plane containing second derivatives is depth-integrated by using the Leibniz rule. The integrated wave equation is then applied to...

Assume fluid eddy viscosity in the vertical direction is parabolic. Sediment particles diffuse with the given fluid eddy viscosity. However, when the vertical diffusion coefficient profile is computed from the suspended sediment concentration profile, the coefficient shows lager values than the fluid mixing coefficient values. This trend was explai...

The need and importance of developing and utilizing the oceans, not only as sources of renewable energy and mineral resources, but also as countermeasures to global warming such as for CCS (carbon capture and storage), have continued to increase, especially in countries with limited land areas and resources. Therefore, it is necessary to assess the...

The inhomogeneous Helmholtz equation is introduced for variable water depth and potential function and separation of variables are introduced for the derivation. Only harmonic wave motions are considered. The governing equation composed of the potential function for irrotational flow is directly applied to the still water level, and the inhomogeneo...

The effective roughness of ripple beds under a wave regime is investigated. An existing numerical model, KU-2DVW-00, with a mixing length hypothesis is used to simulate the wave boundary layer flow over ripples. The ripple-length-average bed shear stress or form drag friction is obtained from integration of the computed pressure field. The wave fri...

A set of equations for description of transformation of harmonic waves is proposed here. Velocity potential function and separation of variables are introduced for the derivation. The continuity equation is in a vertical plane is integrated through the water so that a horizontal one-dimensional wave equation is produced. The new equation composed o...

A non-linear method, PREC, for computation of the movement of a free surface is proposed here. The method is composed of three steps: identifying the free surface by using a non-linear function from the volume fraction matrix, updating the volume fraction matrix using a volume projection method with error correction, and treatment of the results us...

For the last decade or so, the biggest category of the IT investment has unarguably been Enterprise Resource Planning (ERP). Most of the bigger corporations in the developed countries have implemented ERP systems with an aim to achieving competitive edge in their respective business areas. Now that the top end of the ERP market has been saturated,...

This paper presents Reconciliation+, a method which identifies overlaps between models of software systems behaviour expressed as UML object interaction diagrams (i.e., sequence and/or collaboration diagrams), checks whether the overlapping elements of these models satisfy specific consistency rules and, in cases where they violate these rules, gui...

Profiles of wave-induced current on plane beaches are generally smooth. Previously, the smooth nature was often explained by involving lateral mixing concept. This paper describes a new spreading approach instead of the previous lateral mixing approach. The spreading of the driving forces leads to similar results on the velocity profiles of the pre...

Youngil Bay has a rectangular shape on the east coast of Korea, see Figure 1. Hyungsan River supplies pollutants and water to the center of the bay. The tidal range around the bay is as small as 4 cm, and the circulation of the seawater in the bay is not sufficient to keep the seawater clean since 1975. Waves are relatively strong at the entrance o...

This paper presents a framework for assessing the significance of inconsistencies which arise in object-oriented design models that describe systems from multiple perspectives. The framework allows the definition of significance criteria and measures the significance of inconsistencies as beliefs for the satisfiability of these criteria.

Variations of suspended sediment concentration over ripples in regular waves were described using an existing numerical model system. Nielsen's (1992) empirical formula for sediment entrainment rate from the bed surface was used with an additional scale factor in the model system. The model system was applied to two typical laboratory experimental...

This paper presents: (a) a framework for assessing the significance of inconsistencies which arise in object-oriented design models that describe software systems from multiple perspectives, and (b) the findings of a series of experiments conducted to evaluate it. The framework allows the definition of significance criteria and measures the signifi...

The flow behavior of turbulent wave boundary layers with weak currents was described using a numerical model. Horizontal velocities, shear stresses, turbulent eddy viscosities, and apparent roughnesses were described. The numerical model is based upon the fluid continuity and momentum equations in the vertical plane. The momentum equations retain t...

An existing numerical model system for the flow field and suspended sediment concentration for oscillatory flow has been applied to a laboratory condition involving regular waves. The flow field was obtained from an existing model proposed by Kim et al., which is a modified CFD package SOLA based on SMAC scheme. The flow sub-model solves the contin...

This paper presents Reconciliation+, a tool-supported method which identifies overlaps between models of different object interactions expressed as UML sequence and/or collaboration diagrams, checks whether the overlapping elements of these models satisfy specific consistency rules, and guides developers in handling these inconsistencies. The metho...

Software design patterns are a way of facilitating design reuse in object-oriented systems by capturing recurring design practices. Lots of design patterns have been identified and, further, various usages of patterns are known, e.g., documenting frameworks and reengineering legacy systems [8,15]. To benefit fully from using the new concept, we nee...

Little assistance, if any, is given to personnel who design software. This has caused the production of software which is less evolvable and of low quality. A case study was carried out to investigate the implications of design patterns during software building. The results suggest that design patterns can facilitate our understanding of software s...

Software design is difficult because it is not guided well. That has caused the software crisis ever since the software engineering discipline itself started. Design patterns and frameworks aid in reusing software designs by capturing commonalities across software projects. This paper surveys the current ways of formalising design patterns and fram...

The phenomenal growth in the costs of producing software over the last three decades has forced the computing industry to look for alternative strategies to that implied by the waterfall model of computer system development. One frequently observed solution is flint of reusing existing software artifacts in the construction of new ones; this techni...

A technique to combine different size grids in a computational domain is proposed. While existing nesting methods which link two or more grids for hydrodynamic problems cannot treat the inter-tidal zones, the present model can be applied to the areas which repeat dry and wet conditions

The phenomenal growth in the costs of producing software over the last three decades has forced the computing industry to look for alternative strategies to that implied by the waterfall model of computer system development. One frequently observed solution is that of reusing the code from previously designed systems in the construction of new ones...

The paper describes the development and application to laboratory and North Sea field data of a series of random wave and current computer models of bed boundary layer flows and associated suspended sediment concentrations. The EC-funded (MAST 1) work is part of a larger project, which also includes the laboratory testing of a new seabed shear stre...

Uses depth-averaged current velocity, depth-varying bed shear strengths, and discretizes a sea-bed into several layers according to the shear strength profile. The liquefaction of a new top layer due to erosion is also considered. Stationary suspension layers consist of only mud by assuming selfweight sorting while lower layers are mixed with cohes...

The present paper describes the application of a range of computer models to describe the seasonal variation of seabed bathymetry in the vicinity of Chukpyon Harbour, which is situated on the east coast of Korea. The coastal conditions at the harbour site are dominated by waves and wave-induced currents. Consequently, wave-period-average models wer...

A depth averaged two-dimensional sediment transport model is proposed which solves the advection-diffusion equation for suspended load using a finite difference method and adopts the empirical formula of van Rijn (1982) for bed load. The model shows quantitatively good agreements with field observations in the application to Kum River Estuary. -fro...

This paper proposes some new software metrics that can be applied to UML modelling elements like classes and messages. These metrics can be used to predict var-ious characteristics at the earlier stages of the software life cycle. A CASE tool is de-veloped on top of Rational Rose 1 using its BasicScript language and we provide some examples using i...