• Journal of Industrial Technology
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• v.2
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• pp.45-51
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• 1982

Schwartz-Christofel transformation has been widely used to solve engineering problems. In this paper, this transformation is used to calculate topographic problems. Any two points of z-plane are transformed into ${\xi}$-plane by Schwartz-Christofel transformation using calculator.

• Journal of Radiation Protection and Research
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• v.12 no.2
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• pp.28-36
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• 1987

Gaussian plume model is used to assess environmental dose for abnormal radioactive release in nuclear facility, but there has a problem to use it for complex terrain. In this report, MATTEW and WIND04 Codes which had been verified were used to calculate wind field in the complex terrain. Under the base of these codes principle, wind fields were obtained from the calculation of the finite difference approximation for advection-diffusion equations which satisfy the mass-conservative law. Particle concentrations and external doses were calculated by using PIC model which approximate the particle to radioactive cloud, and atmospheric diffusion of the particles from the random walk method. The results show that the adjusted wind fields and the distributions of the exposure dose vary with the topography of the complex terrain.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.6
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• pp.87-95
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• 2011

This study investigates Youl Chon Industrial Complex 1 by dividing into three regions : the drainage site, the area inside the complex, and the seaside. Then each region was subdivided into three areas resulting in a total of nine areas for soil sampling and analysis. After analyzing the physical and chemical properties of the soil, all nine area's pH and EC readings indicated that the soil condition is not suitable for vegetation growth (according to the previous study, the pH level was 5.8 and EC was 2.0dS/m). Therefore, for Youl Chon Industrial Complex 1 to become green, the neutralization and reduction of pH and EC level is needed; first, vegetation through dredging soil, and second, introduction of halophytes is suggested. This study finds out that vertical changes in physical and chemical properties of soils in reclaimed sites are very variable and the result depends on surrounding environments, so it suggested the basic data for building vegetation or reclaimed sites. However, the additional study aiming at various reclaimed sites is required as this study was conducted only to limited areas, and this study has left monitoring analysis as the follow-up task to check the relations between a plant community and soils.

• The Korean Journal of Ecology
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• v.19 no.3
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• pp.201-207
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• 1996

Selection of Al tolerant woody plants, and possibility of reforestation with the Al tolerant plants in soil conditions with different Al content, topography and slope exposures were studied on the slopes around Yeocheon Industrial Complex. Root growth in length of plants grown in 1/2 Steinberg solution decreased with increased Al concentrations of the solution. Relative root length showed that Paulownia coreana, Celtis sinensis and Firmiana simplex were sensitive to $500\muM$ Al, Pinus koraiensis, Alnus japonica and Ligustrum japonicum were intermediate, and Pinus rigida, P. densiflora and P. thunbergii were tolerant to $1, 000\muM$ Al. Coniferous plants appeared to be more tolerant to Al than deciduous ones. Soil pH was 4.2 and Al content was 509 ppm in average around the Yeocheon industrial complex. Al content and soil acidity were more deteriorated on the foothill and slope facing to the pollution source from the industrial complex than on the ridge and opposite slope.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.2
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• pp.59-62
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• 1992

Empirical criteria for wave breaking on the coastal slope are substantiated theoretically for complex-shape basins. The theory developed here is a generalization of Carrier-Greenspan theory for a plane beach. The place and role of the linear theory for the description of run-up problem is discussed. The height of run-up on the beach of the basins with a “parabolic” profile is calculated for originally monochromatic wave.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5801-5812
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• 2014

The retention basin is a hydraulic structure for flood mitigation by storing river flow over a design flood. In this study, numerical models were adopted to simulate the flood mitigation effects by a retention basin. The large flood condition was applied as a boundary condition to consider an abnormal flood caused by climate change. Furthermore, the two-dimensional numerical model was adopted to regenerate the complex flow pattern due to the topography and lateral flow near the retention basin. The numerical results of the one- and two-dimensional model were analyzed and compared. The results showed that the two-dimensional model is more applicable to assessing flood mitigation by the retention basin with a complex topography and lateral flow patterns.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.529-538
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• 2012

By using an algorithm derived by a multiple linear regression analysis, a technique for filtering was developed; and by using the developed technique, the results of conducting filtering of the raw data collected via scanning with a terrestrial LiDAR the actual sloped terrain was analyzed. As such, when filtering was applied by dividing the observation areas into two areas with the topographical line as a reference in order to improve the filtering accuracy, it was seen that the filtering accuracy improved by about 8.73% as compared to when filtering was applied without dividing the observation area. In addition, considering the fact that the accuracy improved by 5~7% when the sloped sides of a multicurvature topography were divided and a complex filtering applied as compared to when filtering was applied for the entire area or by regions, it can be asserted that the accuracy was higher when a complex filtering was conducted by dividing the sloped areas where the slope is not constant due to the multi-curvature of topography.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.4
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• pp.152-158
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• 2018

PVT (Physical Vapor Transport) method has advantages in producing high quality, large scale wafers where many researches are being carried out to commercialize nitride semiconductors. However, complex process variables cause various defects when it had non-equilibrium growth conditions. Annealing process after crystal growth has been widely used to enhance the crystallinity. It is important to set appropriate temperature, pressure, and annealing time to improve crystallinity effectively. In this study, the effect of the annealing conditions on the crystalline structure variation of the AlN single crystal grown by PVT method was investigated with synchrotron whitebeam X-ray topography, electron backscattered diffraction (EBSD), and Rietveld refinement. X-ray topography analysis showed secondary phases, sub-grains, impurities including carbon inclusion in the single crystal before annealing. EBSD analyses identified that sub-grains with slightly tilted basal plane appeared and the overall number of grains increased after the annealing process. Rietveld refinement showed that the stress caused by the temperature gradient during the annealing process between top and bottom in the hot zone not only causes distortion of grains but also changes the lattice constant.

• Geophysics and Geophysical Exploration
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• v.4 no.2
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• pp.34-44
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• 2001

Forward modeling by construction of synthetic data is usually practiced in a horizontal surface and a few subsurface structures. However, in-situ surveys often take place in such topographic changes that the corrupted field data always make it difficult to interpret the right signals. To examine the propagation characteristic of elastic waves on the irregular surface, a general mesh generation code for finite element method was modified to consider the topography. By implementing this algorithm, the time domain modeling was practiced in some models with surface topography such as mound, channel, etc. The synthetic data obtained by receivers placed on surface also agreed with the analytic solution. The snapshots showing the total wave-field revealed the propagation characteristic of the elastic waves through complex subsurface structures and helped to identify the signals on the time traces. The transmission of Rayleigh waves along the surface, compressive waves, and sheer waves was observed. Moreover, it turned out that the Rayleigh waves behave like a new source at the edge.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.42-50
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• 2016

This study presents a performance evaluation of four different land surface models (LSM) available in Weather Forecast Research (WRF). The research site was located in Haean Basin in South Korea. The basin is very unique by its geomorphology and topography. For a better representation of the complex terrain in the mesoscale model were used a high resolution topography data with a spatial resolution of 30 meters. Additionally, land-use layer was corrected by ground mapping data-sets. The observation equipments used in the study were an ultrasonic anemometer with a gas analyzer, an automatic weather station and a tethered balloon sonde. The model simulation covers a four-day period during autumn. The result shows significant impact of LSM on meteorological simulation. The best agreement between observation and simulation was found in the case of WRF with Noah LSM (WRF-Noah). The WRF with Rapid Update Cycle LSM (WRF-RUC) has a very good agreement with temperature profiles due to successfully predicted fog which appeared during measurements and affected the radiation budget at the basin floor. The WRF with Pleim and Xiu LSM (WRF-PX) and WRF with Thermal Diffusion LSM (WRF-TD) performed insufficiently for simulation of heat fluxes. Both overestimated the sensible and underestimated the latent heat fluxes during the daytime.