• Journal of Ocean Engineering and Technology
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• v.20 no.5 s.72
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• pp.23-29
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• 2006

A quasi depth-varying mathematical model for wind-generated circulation in coastal areas, expressed in terms of the depth-averaged horizontal velocity components and free surface elevation was validated and used to understand the diurnal circulation process. The wind velocity is considered as a dominant factor for driving the current. In this paper, three-dimensional numerical experiments that included the land topography were used to investigate the mesoscale air flaw over the coastal regions. The surface temperature of the inland area was determined through a surface heat budget consideration with the inclusion of a layer of vegetation.A series of numerical experiments were then carried out to investigate the diurnal response of the air flaw and wind-generated circulation to various types of surface inhomogeneities.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.24-28
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• 2011

This paper reviews a ceiling prediction method based on a mesoscale meteorological modeling system in South Korea. The study was motivated by the tendency of higher model ceiling height than the observed in daily operational forecasts. The goal of the paper is to report an effort to improve the operational ceiling prediction skill by conducting numerical experiments controlling a model parameter. In a case experiment, increasing constant values used in the relationship between extinction coefficients and concentration showed better performance, indicating a short-term strategy for operational local ceiling forecast improvement.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.2
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• pp.96-104
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• 1991

An investigation is carried out for the roles of the synoptic meteorology in governing $SO_2$ concentrations in Seoul during the wintertime. This study has used the daily records of wind and temperature measured at the Korea Meteorological Administration in Seoul. A one-dimensional diffusion model has been used for investigating the influence of the mixing height on the diurnal variation of concentration. The day to day variations of the concentration are well correlated with those of wind and temperature. The diurnal variation of the concentration is dictated by the variation of mixing height. It is also found that mesoscale wind field is required to explain the mesoscale distribution of the concentration.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.46-54
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• 2000

Three dimensional numerical experiments that included the land-use transformation by the large scale reclamation were used to investigate the mesoscale air flow over the coastal regions. In this paper the surface temperature of the inland was determined through the surface heat budget consideration with inclusion of a layer of vegetation. The vertical diffusion coefficients of momentum, heat and specific humidity in the constant flux layer were taken from the Mellor and Yamada(1975). It has shown that the resulting model is able to reproduce the air circulation in coastal regions, and the simulated characteristics agree with the known properties of this circulation. A series of numerical experiments were then carried out to investigate the diurnal response of the air flow to various types of surface inhomogeneities.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.413-417
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• 2005

A lattice model of a typical bridge column section is analyzed, and results are presented. The lattice is built as an ensemble of line elements and masses, that can capture strain rate dependency of concrete material. The research mainly breaks up into two parts: First, a micro level analysis of the material is executed, and control parameters of the governing equations are derived by matching the results with the common macroscopic properties of concrete material. Then, the properties exhibited by the micro model, which extends the classical material properties are applied to the mesoscale model. Hence, the analysis of the target structure can be performed. In the mesoscale analysis, ramp-like impulse loads are applied at different velocity, so that the contribution of the material level rate dependency to the global behavior of the structure can be tracked.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.226-231
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• 2003

A coupling system of MM5 and POM using Stampi with different kinds of parallel computer is proposed and comparative numerical simulations of mesoscale wind induced by topography around East Sea/Sea of Japan are carried out. The results are as follows： 1) Strong horizontal conversion is induced by high mountain Pekdoo at its leeside. 2) The conversion winds at lee of high mountain are not clear in monthly and yearly mean NCEP-reanalysis because of coarse resolution of 1.86 degree by 1.86 degree. But Wind conversion is well simulated at atmosphere and ocean coupling system. And the conversion area of lee side of mountain is also agreed well with observed data of NSCAT launched in satellite ADEOS. 3) The surface ocean current is well correspondent with wind direction, induced by high mountains. And small different wind field information lead the different of particle distribution in numerical experiments of particle distribution on ocean surface.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.164-169
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• 2003

The need fur higher grid resolution in climate models is often discussed (e.g. McAvaney et al.,2001) because a number of important oceanic processes are not resolved by the current generation of coupled models, e.g., boundary currents, mesoscale eddy fluxes, sill through flows. McClean et al., (1997) and Bryan and Smith (1998) have compared simulated mesoscale variability in simulations at several eddy-resolving resolutions to TOPEX/Poseidon and similar data. (omitted)

• International Journal of High-Rise Buildings
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• v.1 no.2
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• pp.73-80
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• 2012

In order to use sea breezes to counter the heat island phenomena, i.e. to promote urban ventilation, it is necessary to clarify the effect of building morphology and height on large-scale wind fields. In this study, the sea breeze in the vicinity of the Kanto Plain in Japan is simulated using a mesoscale meteorological model incorporating an urban canopy model, and the inland penetration of sea breezes is accurately reproduced. Additionally, a mean kinetic energy balance within a domain (Control Volume; CV) moving along the sea breeze is analysed. From the results, it is clarified that the sea breeze is interrupted by the resistance and turbulence caused by buildings at the centre of Tokyo. The interruption effect is increased in accordance with the height of these buildings. On the other hand, adverse pressure gradients interrupt in the internal region.

• Structural Engineering and Mechanics
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• v.32 no.2
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• pp.235-249
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• 2009

The response of concrete structures subjected to shock and blast load involves a rapid transient phase, during which material breach may take place. Such an effect could play a crucial role in determining the residual state of the structure and the possible dispersion of the fragments. Modelling of the transient phase response poses various challenges due to the complexities arising from the dynamic behaviour of the materials and the numerical difficulties associated with the evolving material discontinuity and large deformations. Typical modelling approaches include the traditional finite element method in conjunction with an element removal scheme, various meshfree methods such as the SPH, and the mesoscale model. This paper is intended to provide an overview of several alternative approaches and discuss their respective applicability. Representative concrete material models for high pressure and high rate applications are also commented. Several recent application studies are introduced to illustrate the pros and cons of different modelling options.

• 한국지구과학회:학술대회논문집
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• 2005.09a
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• pp.349-355
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• 2005