• Spatial Information Research
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• v.20 no.4
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• pp.1-16
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• 2012

There is no doubt that the urban heat island (UHI) is a mounting problem in built-up environments, due to energy retention by the surface materials of dense buildings, leading to increased temperatures, air pollution, and energy consumption. To investigate the UHI, three-dimensional (3-D) information is necessary to analyze complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with two-dimensional (2-D) urban surface information to examine the relationship between urban characteristics and temperature. In addition, this research introduces spatial regression models to account for the spatial spillover effects of urban temperatures, and includes the following steps: (a) estimating urban temperatures, (b) developing a 3-D city model, (c) generating urban parameters, and (d) conducting statistical analyses using both Ordinary Least-Squares (OLS) and Spatial Regression Models. The results demonstrate that 3-D urban characteristics greatly affect temperatures and that neighborhood effects are critical in explaining temperature variations. Finally, the implications of the results are discussed, providing guidelines for policies to reduce the UHI.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.2
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• pp.128-133
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• 2000

Numerical analysis of the transport phenomena in an inductively coupled plasma reactor was conducted with two-dimensional axisymmetric model including the electromagnetic field model, electron and species density models. The spatial distribution of the charged species in the ion flux to the wafer have been calculated to examine the influence of the process conditions including antenna and reactor geometry. The antenna radius had a significant influence on the plasma state and axial ion flux distribution.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.672-678
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• 2014

We propose a method to estimate the 3-D shape of surfaces with specular reflection, using a model of the difference in appearance between images reflected from a flat surface and a curved surface. First, we analyze the geometry of spatial reflection from a specular surface and how reflected light varies due to a curved surface. This is used to estimate 3-D shape. The proposed method is shown to be effective in experiments using illumination from spatially distributed light sources and a camera capturing the reflected light from curved, specular surfaces.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.344.2-344
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• 2002

In this presentation, a power-based spatial filtering procedure with application to spherical acoustical holography is presented. Planar and cylindrical holography are the most widely used amongst the various nearfield acoustical holography techniques. However, when the geometry of a source is similar to a sphere. spherical holography may yield better results than other types of holography since there are no errors due to truncation of the sound field in the spherical case. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.730-734
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• 2003

A beamforming method is a kind of spatial filter that focus the amy's signal capturing abilities in a desired direction. In this paper, we detect the location of a source under reflective condition using the multi-dimensional MUSIC algorithm then, we can iud the image source locations from the experimental geometry, and we reconstruct the partial fields for direct wave and reflected wave by using Adaptive nulling algorithm. Numerical simulations are performed to verify its performance under various conditions.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.137-141
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• 1996

A new general high order consistent nodal method for solving the 3-D multigroup neutron kinetic equations in (x-y-z) geometry has been derived by expending the flux in a multiple polynomial series for the space variables by without the quadratic fit approximations of the transverse leakage and for the time variable and using a weighted-integral technique. The derived equation set is consistent mathematically, and therefore, we can expect very accurate solutions and less computing time since we can use coarse meshes in time variable as well as in spatial variables and the solution would converge exactly in fine mesh limit.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.10
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• pp.2548-2566
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• 2012

This paper derives two main end-to-end performance metrics, namely the spatial capacity density and the average end-to-end delay of the multi-hop wireless ad hoc networks with multi-antenna communications. Based on the closed-form expressions of these performance metrics, three hopping strategies, i.e., the closest neighbor, the furthest neighbor and the randomly selected neighbor hopping strategies have been investigated. This formulation provides insights into the relations among node density, diversity gains, number of hops and some other network design parameters which jointly determine network performances, and a method of choosing the best hopping strategy which can be formulated from a network design perspective.

• Communications of the Korean Mathematical Society
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• v.17 no.4
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• pp.647-673
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• 2002

There are many models to study topological $R^2$-planes. Unlike topological $R^2$-planes, it is difficult to find models to study topological R$^3$)-spaces. If an 4-dimensional affine plane intersects with R$^3$, we are able to get a geometrical structure on R$^3$ which is similar to R$^3$-space, and called $R^2$-divisible R$^3$-space. Such spatial geometric models is useful to study topological R$^3$-spaces. Hence, we introduce some classes of topological $R^2$-divisible R$^3$-spaces which are induced from 4-dimensional anne planes.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.11-18
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• 2005

Filament inversion routines are highly effective for target definition whenever total-field DHTEM vectors can be obtained using three-component logging tools. However most cross-hole components contain significant noise related to sensor design and errors in observation of probe rotation. Standard stacking methods can be used to improve data quality but additional statistical methods based on cross-correlation and spatial averaging of orthogonal components may be required to ensure a consistent vector migration path. Apart from assisting with spatial averaging, multiple filaments generated for successive time-windows can provide additional imaging information relating to target geometry and current migration. New digital receiver systems provide additional time-windows to provide better tracking options necessary for high-resolution imaging of this type.

• Journal of Korean Association for Spatial Structures
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• v.2 no.3 s.5
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• pp.115-122
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• 2002

It is often hard to obtain analytical solutions of boundary value problems of shells. Introducing some approximations into the governing equations may allow us to get analytical solutions of boundary value problems. Instead of an analytical procedure, we can apply a numerical method to the governing equations. Since the governing equations of shells of revolution under symmetric load are expressed by ordinary differential equations, a numerical solution of ordinary differential equations is applicable to solve the equations. In this paper, the governing equations of orthotropic spherical shells under symmetric load are derived from the classical theory based on differential geometry, and the analysis is numerically carried out by computer program of Runge-Kutta methods. The numerical results are compared to the solutions of a commercial analysis program, SAP2000, and show good agreement.