• Proceedings of the Korean Institute of Interior Design Conference
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• 2003.05a
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• pp.135-138
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• 2003

Skin, the complex membrane that holds the body together, also embraces the full spectrum of design today-from product to architecture, fashion, and media. Every object has a skin. thick or thin, smooth or rough, porous or impermeable, the skin is the line between a hidden interior and an exterior we experience. Skin： Surface, Substance and Design is a compendium of products, furniture, fashion, architecture and media that expand the limits of what we understand as surface. Reflecting the convergence of natural and artificial life, this provocative a thesis shows how enhanced and simulated skins appear everywhere in today's world.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1601-1607
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• 2000

Using the theory of linear piezoelectricity, we consider the problem of piezoelectric ceramic infinite strip containing a finite crack with free surface traction and surface charge under anti-plane shear. The crack is symmetrically parallel to the edges of infinite strip. Fourier transforms are used to reduce the problem to two pairs of dual integral equations, which are then expressed in terms of Fredholm integral equations of the second kind. Numerical results for PZT-5H ceramic are obtained and discussed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.85-88
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• 2001

Since mountainous area has access restrictions for field work, assessors need to establish a conceptual model of the contamination prior to the field investigation. In this study we established a conceptual model of the contamination based on site inspection and geological survey, followed by the field investigation for the petroleum spill site. In the conceptual model, we estimated that tile contamination should have spread by groundwater and topographical characteristics within the top soil layer. The spread of contamination through rock was not considered in the conceptual model due to impermeable characteristics of metasyenite. The contaminated environmental media of the petroleum spill site include soil and groundwater. According to the analysis result of the contamination, the volume of contaminated soil is estimated approximately 4, 150 cubic meters (7, 055 ton) with most contaminants existing along the groundwater flow within top soil layer.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.628-635
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• 2007

As the hydrologic cycle is transformed by the expansion of impermeable area as a result of the urbanization, the function of an ecosystem is deteriorated by the transformed hydrologic cycle. In this study, a SWMM code was modified to have a groundwater pumping option about rivers-aquifer interaction to be possible. The modified SWMM was applied to continuous simulations of urban runoff from Hakuicheon watershed and it was used to analyse the effect of a groundwater pumping. The modified SWMM overcame the limitation of the ground subroutine that it only simulate groundwater inflow from ground to rivers. The result of continuous simulation of groundwater pumping is that surface runoff, groundwater runoff and groundwater level are well simulated, and Modified SWMM expressed groundwater runoff by negative number (-) when groundwater level is less than river stage.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.66-69
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• 2001

A subsurface containment system which is constructed by pumping a gelling liquid (Colloidal Silica) into the unsaturated medium is investigated by developing a mathematical model and conducting numerical simulations. The proposed model is verified by comparing experimentally and numerically determined hydraulic conductivities of gel-treated soil columns at different Colloidal Silica (CS) injection volumes. The numerical experiments indicate that an impermeable gel layer is formed within the time period twice the gel-point. At the Same normalized time, the CS solutions with lower NaCl concentrations result ill further migration and poor Performance in plugging the pore space.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1172-1177
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• 2010

For the deep excavation in urban area, the braced-cut method is mainly adopted. In this case, inadequate consideration of ground water level may result in wrong prediction of structural behavior. In this study, the effects of hydraulic interaction between wall and grout were investigated using the finite element method. The maximum stress in case of confined ground water condition is obtained at the final excavation stage in the range of 70~80% of excavation depth. The stress of impermeable case is about 50% larger than that of permeable case. When the relative permeabililty of wall-grout become smaller, the stress is getting bigger. And the stress tends to converge in case of 1/100 or less of the relative permeability.

• International Journal of Ocean System Engineering
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• v.1 no.2
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• pp.89-94
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• 2011

Underwater localization is a crucial capability for reliable operation of various types of underwater vehicles including submarines and underwater robots. However, sea water is almost impermeable to high-frequency electromagnetic waves, and thus absolute position fixes from Global Positioning System (GPS) are not available in the water. The use of acoustic telemetry systems such as Long Baseline (LBL) is a practical option for underwater localization. However, this telemetry network system needs to be pre-deployed and its availability cannot always be assumed. This study focuses on demonstrating the validity of terrain-based localization techniques in a GPS-denied underwater environment. Since terrain-based localization leads to a nonlinear estimation problem, nonlinear filtering methods are required to be employed. The extended Kalman filter (EKF) which is a widely used nonlinear filtering algorithm often shows limited performance under large initial uncertainty. The feasibility of using a particle filter is investigated, which can improve the performance and reliability of the terrain-based localization.

• KSBB Journal
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• v.4 no.2
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• pp.150-156
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• 1989

The chaacterisitics of a commercial membrance-coverd electrode in air-saturated saline solution were investigated in terms of a steadystate one-dimensional model. The electrode system miiersed in an aqueous medium consists of three layers: an external concentration boundary layer, a membrance, and an inner electrolyte layer. The membrance can be permeabld to the water and impermeable to the ionic species. In stationary midium, the water migrates from the external medium to the inner electrolyte layer until a thermodynamic equilibrium is reached. In a following midium, however, there is a reverse direction of water movement due to the hyrodynamic pressure differential until both thickness of the electrolyte layer and the membrance are equal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.2
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• pp.35-43
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• 1984

The purpose of this paper is to develop a mathematical model which can be used to compute the position of the free surface due to water level fluctuations in the canal and the transient pressure distributions along the canal lining. The diagnostic equation has been solved by the point successive over-relaxation method, and the linearized prognostic equation has been solved by the implicit Lax-Wendroff scheme. Four different cases in the simulation conditions are presented for both permeable and impermeable canal lining to predict the transient seepage surface development.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.967-974
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• 2007

A general form solution is considered for a piezoelectric material containing impermeable cracks subjected to a combined mechanical and in-plane electrical loading. The analysis is based upon the Hilbert problem formulation. Using this solution, typically for a central crack in transverse isotropic piezoelectric material, a closed form solution is obtained, where one concentrated mechanical and electrical load is subjected to the crack surface. This problem could be used as a Green's function to generate the solutions of other problems with the same geometry but of different loading conditions.