• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.31-37
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• 2004

GIS 분야에서 다루는 공간 데이터는 대부분 2차원의 데이터이다. 현실 공간에 존재하는 3차원 객체의 2차원 정보만을 취하거나 혹은 2차원 공간으로 투영하는 등의 방법으로 데이터를 저장한다. 이러한 방법은 정보의 손실로 인한 데이터 활용범위가 축소되고, 현실 공간을 정확하게 반영하지 못하는 문제가 있다. 최근 3차원 공간 데이터를 저장, 관리 가능한 DBMS가 개발되고, 3차원 데이터에 대한 관심과 요구가 높아가고 있다. 하지만 3차원 데이터를 단순 저장만 가능할 뿐 공간 연산에 대한 연구가 미흡한 실정이다. 본 연구에서는 3차원 공간 모델을 이용하여 공간 데이터베이스 표준에서 정의하고 있는 공간 관계 연산을 설계하였다. 공간 데이터 모델로는 OGC에서 제시한 GML3에서 정의하는 모델을 사용하였고, 공간 관계 연산에 대한 설계 도구로는 공간 관계를 연산하는데 가장 좋은 방법으로 알려진 DE-9IM을 이용하였다.

• Spatial Information Research
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• v.1 no.1
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• pp.89-94
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• 1993

GIS was appl ied for analysis of the potfnt ial degree of regional geologic hazard, expecially landslide, in the suburb of Seoul city. Potential elements causing a landslide are geology, slope geometry, groundwater, soil property, rainfall and vegetation etc. These factors were incorporated through GIS in order to predict the potential hazards, and to produce a regional geologic hazard map in the study area, For this study, ARC/INFO and ERDAS systems were used in SUN4-390 workstation.

• Journal of Korean Association for Spatial Structures
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• v.14 no.2
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• pp.59-68
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• 2014

A study on the vibration and buckling analyses of laminated composite plates is described in this paper. In order to carry out the analyses of laminated composite plates, a NURBS-based isogeometric general plate element based on Reissner-Mindlin (RM) theory is developed. The non-uniform rational B-spline (NURBS) is used to represent the geometry of plate and the unknown displacement field and therefore, all terms required in this element formulation are consistently derived by using NURBS basis function. Numerical examples are conducted to investigate the accuracy and reliability of the present plate element. From numerical results, the present plate element can produce the isogeometric solutions with sufficient accuracy. Finally, the present isogeometric solutions are provided as future reference solutions.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.34-39
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• 1996

A consistent general order nodal method for solving the 3-D neutron diffusion equation in (x-y-z) geometry has ben derived by using a weighted integral technique and expanding the spatial variables by the Legendre orthogonal series function. The equation set derived can be converted into any order nodal schemes. It forms a compact system for general order of nodal moments. The method utilizes the analytic solutions of the transverse-integrated quasi -one dimensional equations and a consistent expansion for the spatial variables so that it renders the use of an approximation for the transverse leakages no necessary. Thus, we can expect extremely accurate solutions and the solution would converge exactly when the mesh width is decreased or the approximation order is increased since the equation set is consistent mathematically.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6922-6931
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• 2014

The development of modern science and technology and computer engineering breakthroughs in the field of information and communication have brought about many changes in lifestyle. The government announced the goal of educational policy in 2030 to educate people in future society on a future-oriented perspective. Changes in the curriculum along with changes in educational facilities are essential. Therefore, the operation of a classroom should be associated with classroom spatial information. The BIM design based on 3D geometry information was designed. The BIM design can link the design information and non-geometric information of spatial information. This study examined the operation of school facilities based on classroom spatial information with BIM. This study suggests standardization of classroom spatial information based on BIM. The scenarios of BIM ordering and design for departmentalized classrooms management is proposed.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.85-91
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• 2018

Computed tomography, which obtains section images from reconstruction process using projection images, has been applied to various fields. The spatial resolution of the reconstructed image depends on the device used in CT system, the object, and the reconstruction process. In this paper, we investigates the effect of the number of projection images and the pixel size of the detector on the spatial resolution of the reconstructed image under the parallel beam geometry. The reconstruction program was written in Visual C++, and the matrix size of the reconstructed image was $512{\times}512$. The numerical bar phantom was constructed and the Min-Max method was introduced to evaluate the spatial resolution on the reconstructed image. When the number of projections used in reconstruction process was small, artifact like streak appeared and Min-Max was also low. The Min-Max showed upper saturation when the number of projections is increased. If the pixel size of the detector is reduced to 50% of the pixel size of the reconstructed image, the reconstructed image was perfectly recovered as the original phantom and the Min-Max decreased as increasing the detector pixel size. This study will be useful in determining the detector and the accuracy of rotation stage needed to achieve the spatial resolution required in the CT system.

• Journal of the Korea Furniture Society
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• v.23 no.1
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• pp.75-83
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• 2012

Space dominates all the art activities human do and plays a role of providing aesthetic emotion. Architecture, sculpture, painting, and furniture, etc. these two and three dimensional works are represented in space and interpreted the role of its form, structure and function. Each area is different, but space has been studied in philosophy, physics, geometry, and mathematical studies, etc. and has been consistently interpreted and represented relating to a variety of human creative activity. Furniture is also three dimensional art being dependent on space. In the United States in 2004, I made the living room bench by applying the spatial concept at Rochester Institute of Technology. Two years later, this design was adopted by wendell Castle Collection, an American furniture company, then prototype were made and tested three times during a year, and then since 2007 as indoor benches it has been manufactured in the United States. The study's purpose is to order the process of its development based on the experience of bench production applied the spatial concept, and by analyzing the properties of spatial concept, I am planning to propose a new concept on interaction with the space and furniture for next.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.321-324
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• 2005

In these days, the management and visualization of 3D geo-spatial information is regarded as one of an important issue in GiS and remote sensing fields. 3D GIS is considered with the database issues such as handling and managing of 3D geometry/topology attributes, whereas 3D visualization is basically concerned with 3D computer graphics. This study focused on the design and implementation for the OpenGL API-based rendering system for the complex types of 3D geo-spatial features. In this approach 3D features can be separately processed with the functions of authoring and manipulation of terrain segments, building segments, road segments, and other geo-based things with texture mapping. Using this implementation, it is possible to the generation of an integrated scene with these complex types of 3D features. This integrated rendering system based on the feature-based 3D-GIS model can be extended and effectively applied to urban environment analysis, 3D virtual simulation and fly-by navigation in urban planning. Furthermore, we expect that 3D-GIS visualization application based on OpenGL API can be easily extended into a real-time mobile 3D-GIS system, soon after the release of OpenGLIES which stands for OpenGL for embedded system, though this topic is beyond the scope of this implementation.

• Journal of Digital Contents Society
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• v.15 no.3
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• pp.347-355
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• 2014

The general octree structure is common for various applications including computer graphics, geometry information analysis and query. Unfortunately, the general octree approach causes duplicated sample data and discrepancy between sampling and representation positions when applied to sample continuous spatial information, for example, signed distance fields. To address these issues, some researchers introduced the dual octree. In this paper, the weakness of the dual octree approach will be illustrated by focusing on the fact that the dual octree cannot access some specific continuous zones asymptotically. This paper shows that the primal tree presented by Lefebvre and Hoppe can solve all the problems above. Also, this paper presents a three-dimensional primal tree traversal algorithm based the Morton codes which will help to parallelize the primal tree method.

• Korean Journal of Remote Sensing
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• v.31 no.4
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• pp.321-330
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• 2015

Atmospheric correction is an essential part in time-series analysis on biophysical parameters of surface features. In this study, we tried to examine possible problems in atmospheric correction of multitemporal High Spatial Resolution (HSR) images obtained from two different sensor systems. Three KOMPSAT-2 and two IKONOS-2 multispectral images were used. Three atmospheric correction methods were applied to derive surface reflectance: (1) Radiative Transfer (RT) - based absolute atmospheric correction method, (2) the Dark Object Subtraction (DOS) method, and (3) the Cosine Of the Uun zeniTh angle (COST) method. Atmospheric correction results were evaluated by comparing spectral reflectance values extracted from invariant targets and vegetation cover types. In overall, multi-temporal reflectance from five images obtained from January to December did not show consistent pattern in invariant targets and did not follow a typical profile of vegetation growth in forests and rice field. The multi-temporal reflectance values were different by sensor type and atmospheric correction methods. The inconsistent atmospheric correction results from these multi-temporal HSR images may be explained by several factors including unstable radiometric calibration coefficients for each sensor and wide range of sun and sensor geometry with the off-nadir viewing HSR images.