• Journal of the Korean Geographical Society
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• v.49 no.3
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• pp.438-455
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• 2014

This study aims at providing a set of viable answers regarding the projection and cartographic scale of Daedongyeojido through a GIS-based planimetric accuracy analysis. Both global and local analyses were undertaken in the use of an analytical tool, MapAnalyst. The main results from the global analysis are threefold. First, the overall cartographic scale turned out to be between 1:158,000 and 1:162,000. Second, the rotation angles were between $2^{\circ}$ and $3^{\circ}$, and the equidistant cylindrical projection reported the smallest value. Third, in terms of position accuracy, the conformal cylindrical projection showed a best fit to the map. A local analysis was undertaken for the conformal cylindrical and equidistant azimuthal projections and its main results are threefold. First, the largest distortions in terms of the displacement vectors and distortion grid were found in the northern borderlands. Second, from the isoline maps of scales, it was acknowledged that local scales between 1:170,000 and 1:175,000 were found around the middle part of the Korean peninsula centered on Seoul. As away from the region to the north-south direction, increasingly larger scales were distributed, while the smallest ones were found in the western and eastern edges of the peninsula. Third, from the isoline maps of rotation, it was known that areas west of a northernmost city (Junggangjin) were substantially rotated to the west, while ones east of it to the east. For a more sophisticated analysis, some need to be done to have a larger set of control points, a better way of postulating the map projection, and a more advanced set of techniques for a local analysis.

• Journal of Korea Water Resources Association
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• v.54 no.8
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• pp.553-566
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• 2021

River confluence is often characterized by shear layer and the associated strong mixing. In natural rivers, the main channel and its tributary can be separated by the shear layer using contrasting colors. The shear layer can be easily observed using aerial images from satellite or unmanned aerial vehicles. This study proposes a low-cost identification method extracting geographic features of the shear layer using RGB aerial image. The method consists of three stages. At first, in order to identify the shear layer, it performs image segmentation using a Gaussian mixture model and extracts the water bodies of the main channel and tributary. Next, the self-organizing map simplifies the flow line of the water bodies into the 1-dimensional curve grid. After that, the curvilinear coordinate transformation is performed using the water body pixels and the curve grid. As a result, the shear layer identification method was successfully applied to the confluence between Nakdong River and Nam River to extract geometric shear layer features (confluence angle, upstream- and downstream- channel widths, shear layer length, maximum shear layer thickness).

• Korean Institute of Interior Design Journal
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• v.23 no.2
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• pp.12-20
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• 2014

The purpose of this study is to analyze the general patterns of the floor plans and space of Usonian house which designed by Frank Lloyd Wright. this thesis can be summarized as follows : 1) F.L.Wright's houses mostly used simple geometric shapes as the basis for most of his architectural designs. In his early works, his typical floor plans were square or rectangular shapes, which gradually were transformed into various kinds of shape to make the adjustment of location of the site and shape. 2) The general patterns of floor plans of his U-houses were L-shaped or straight shaped using a $4{\times}4$ grid system. Most of U-houses consisted of 3 space: living room, workspace(Kitchen) & dining, and bedroom. Among them, a workspace worked as core role in each house. 3) Even though solid wall is the opposite concept of the transparent glass but most U-houses were designed to have solid walls on one side to provide a gallery space(to secure habitability of resident) and transparent glass walls used on the other side to connect between interior space and natural space of exterior. 4) The cantilever have not been used before Usonian house but F.L.Wright used it which take charge of functions as transfer space between inside space and outside space. 5) F.L.Wright saw the nature as a truth, so he thought the interior space would be natural and all houses must be able to adjust to the natural environment.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.403-406
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• 2005

In order to evaluate the Capability of ETM+ remotely- sensed data to provide 'Forest-shrub land-Rangeland' cover type map in areas near the timberline of northern forests of Iran, the data were analyzed in a portion of nearly 790 ha located in Neka-Zalemroud region. First, ortho-rectification process was used to correct the geometric errors of the image, yielding 0/68 and 0/69 pixels of RMS. error in X and Y axis, respectively. The original and panchromatic bands were fused using PANSHARP Statistical module. The ground truth map was made using 1 ha field plots in a systematic-random sampling grid, and vegetative form of trees, shrubs and rangelands was recorded as a criteria to name the plots. A set of channels including original bands, NDVI and IR/R indices and first components of PCI from visible and infrared bands, was used for classification procedure. Pair-wise divergence through CHNSEL command was used, In order to evaluate the separability of classes and selection of optimal channels. Classification was performed using ML classifier, on both original and fused data sets. Showing the best results of $67\%$ of overall accuracy, and 0/43 of Kappa coefficient in original data set. Due to the results represented above, it's concluded that ETM+ data has an intermediate capability to fulfill the spectral variations of three form- based classes over the study area.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.395-402
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• 2016

Space frame structures considering the components such as forms, layers, grids, etc. are possible to form a large space without interior columns. Here, steels having the yield strengths of 210 MPa to 450 MPa are generally used. The high strength steel (i.e., yield strength of 690 MPa) having suitable weldability, aseismicity and economics have been recently developed. In this paper, the high strength steel is applied to the space frame structures in order to analytically find out their transient responses considering the material and geometric nonlinearities. For various circular dome types of space frame structures, the modal analysis and nonlinear transient analysis are carried out using nonlinear three dimensional finite element analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.5
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• pp.329-337
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• 2016

As a turbulence-enhancing device, a mixing vane, which is installed at a spacer grid of the fuel assembly, plays an important role in improving convective heat transfer by generating either swirl flow in the subchannels or cross flow between the fuel rod gaps. Therefore, both the geometric configuration and the arrangement pattern of a mixing vane are important factors in determining the performance of a mixing vane. In this study, in order to examine the flow-distribution features inside a $5{\times}5$ fuel assembly with split-type mixing vanes, which was used in the benchmark calculation of the OECD/NEA, we conduct simulations using the commercial computational fluid dynamics software, ANSYS CFX R.14. We compare the predicted results with measured data obtained from the MATiS-H (Measurement and Analysis of Turbulent Mixing in Subchannels-Horizontal) test facility. In addition, we discuss the effect of the split-type mixing vanes on the flow pattern inside the fuel assembly.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.667-675
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• 2011

In this paper, we propose an automatic image-to-image registration between high resolution multi-sensor images. To do this, TerraSAR-X image was shifted according to the initial translation differences of the x and y directions between images estimated using Mutual Information method. After that, the Canny edge operator was applied to both images to extract linear features. These features were used to design a cost function that finds matching points based on the similarities of their locations and gradient orientations. For extracting large number of evenly distributed matching points, only one point within each regular grid constructed throughout the image was extracted to the final matching point pair. The model, which combined the piecewise linear function with the global affine transformation, was applied to increase the accuracy of the geometric correction, and the proposed method showed RMSE lower than 5m in all study sites.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.153-158
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• 1998

Since the mid-1990′s, researches on 3D GIS have been regarded as one of main issues both in the academic sites and commercial vendors; recently, some prototyped systems or the first versioned software systems of commercial basis are being reported and released. Unlike conventional 2D GIS, which consists in intelligent structured GIS or desktop GIS, every 3D GIS has its own distinguished features according to data structure-supporting capability, GIS-styled functionality, external database accessibility, interfacing extents with 2D GIS, 3D visualization/texture mapping ability, and so forth. In this study, technical aspects related to system development, SERI-Web3D GIS ver. 1.2, are explained. Main features in this revised 3D GIS can be summarized: 2-tier system model(client-server), VGFF(Virtual GIS File Format), internal GIS import, Feature manager(zoning, layering, visualization evironment), Scene manager(manage 3D geographic world), Scene editor, Spatial analyzer(Intersect, Buffering, Network analysis), VRML exporter. While, most other 3D GISes or cartographic mapping systems may be categorized into 3D visualization systems handling terrain height-field processing, 2D GIS extension modules, or 3D geometric feature generation system using orthophoto image: actually, these are eventually considered as several parts of "real 3D GIS". As well as these things, other components, especially web-based 3D GIS, are being implemented in this study: Surface/feature integration, Java/VRML linkage, Mesh/Grid problem, LOD(Level of Detail)/Tiling, Public access security problem, 3-tier architecture extension, Surface handling strategy for VRML.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.392-392
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• 2011

Carbon nanotubes (CNT) emitter has widely become an attractive mechanism that draws growing interests for cold cathode field emission.$^{1,2}$ CNT yarns have demonstrated its potential as excellent field emitters.$^3$ Extensive simulations were carried out in designing a CNT yarn-based cathode assembly. The focal spot size dependence on the anode surface of the geometric parameters such as axial distance of the electrostatic focus lens from the cathode and the applied bias voltages at the cathode, grid mesh and electrostatic focus lens were studied. The detailed computer simulations using Opera 3D electromagnetic software$^4$ had revealed that a remarkable size of focal spot under a focusing lens triode type set-up design was achieved. The result of this optimization simulation would then be applied for the construction of the CNT yarn based micro-focus x-ray tube with its field emission characteristics evaluated.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.128-135
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• 2012

The purpose of this study is to investigate and analyze the compositional elements of plan of art museums by selecting architectural works, which have strong symbolic meaning when evaluating value, from architectural works by Louis Kahn. First, the centrality of artworks, which are being displayed at the Yale Art Gallery, is complex. It includes three patterns of Void (spatial) Centrality+Symbolic Centrality+Functional Centrality among the five patterns suggested in this study. Second, the ratio system of interior space, which is expressed in the extension of the Yale Art Gallery, can be classified into the floor and walls. The floor used the square 1:1 ratio system. The ceiling used the grid patterns of equilateral triangles (regular tetrahedrons). It was applying a geometric ratio system when creating forms by using one side as a beam and the other sides as decorations of the ceiling. Third, the contours of interior space, which were expressed in Kahn's works, used the method of forming separate space according to the contouring rule (structural unit) defined by columns, and they were used in constructing the entire space through the integration of separate spaces. Fourth, according to the characteristics that were expressed by artworks displayed within the Yale Art Gallery Extension, the concept of accessibility was not as clear as that of residential buildings, because an approach of respecting existing architecture and context was used, rather than the starting point of interior space, or differentiated circulation, which has the function of a determined position.