• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.117-120
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• 2002

A single DSP implementation of 3D sound movement is described. With the use of a realtime 3D acoustic image localization algorithm, an efficient approach is devised for synthesizing the 3D sound movement by interpolating only two parameters of "delay" and "gain". Based on this algorithm, the realtime 3D sound synthesis is performed by a commercially available 16-bit fixed-point DSP with computational labor of 65 MIPS and memory space of 9.6k words, which demonstrates that the algorithm call be used even for the mobile applications.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.41-48
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• 2008

Currently used 3D models, which are mostly focused on visualization of 3D objects and lack topological structure, have limitation in being used for 3D spatial analyses and applications. However, implementing a full topology for the indoor spatial objects is less practical due to the increase of complexity and computation time. This study suggests an alternative method to build a 3D indoor model with less complexity using a spatial DBMS. Storing spatial and nonspatial information of indoor spaces in DB tables enables faster queries, computation and analyses. Also it is possible to display them in 2D or 3D using the queried information. This study suggests a 2D-3D hybrid data model, which combines the 2D topology constructed from CAD floor plans and stored in a spatial DBMS and the 3D visualization functionality. This study showed the process to build the proposed model in a spatial DBMS and use spatial functions and queries to visualize in 2D and 3D. And, then, as an example application, it illustrated the process to build an indoor evacuation simulator.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.320-322
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• 2000

인터넷의 빠른 발전과 하드웨어 속도의 향상에 의해 가상현실이 점차 일반 사용자에게도 가깝게 다가서고 있다. 인터넷 가상현실 언어의 표준인 VRML이 XML의 개발과 발전에 의해 차기 버전을 XML의 장점인 용이한 확장성을 수용하는 X3D라 명명하고 표준화를 진행 중이다. 강력한 Java 3D API와 플랫폼 독립적인 바이트코드의 장점을 살려 표준화 단계인 X3D를 별도의 브라우저 없이도 Java 애플릿을 이용하여 재생할 수 있도록 하고자 하며 또한 앞으로 개발될 X3D 저작도구의 결과물을 Java 3D로 변환하여 Java 3D로 변환하여 Java 3D에 의한 3차원 영상 제작을 손쉽게 구현할 수 있도록 한다. 이를 위한 방법으로 X3D를 Java 3D로 변환하는 번역기가 필요하다. 따라서 본 논문에서는 X3D-Java 3D 번역기의 구조를 설계하고 구현 방법을 제시하고자 한다. XML 파서를 이용하여 X3D를 파싱하고 그의 출력인 AST를 순회하면서 Java 3D 파일을 생성한다. X3D DTD와 Java 3D 클래스의 구조 정보를 독립된 자료로 처리하여 계속 변하게 될 두 언어의 변화에 유동적으로 대처하면서 구현 방법의 큰 변화없이 이용할 수 있게 설계하고자 한다.

• Korean Journal of Remote Sensing
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• v.22 no.5
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• pp.351-356
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• 2006

Based on current practical needs for geo-spatial information on mobile platform, the main theme of this study is a design and implementation of dynamic 3D terrain rendering system using spaceborne imagery, as a kind of texture image for photo-realistic 3D scene generation on mobile environment. Image processing and 3D graphic techniques and algorithms, such as TIN-based vertex generation with regular spacing elevation data for generating 3D terrain surface, image tiling and image-vertex texturing in order to resolve limited resource of mobile devices, were applied and implemented by using graphic pipeline of OpenGL|ES (Embedded System) API. Through this implementation and its tested results with actual data sets of DEM and satellite imagery, we demonstrated the realizable possibility and adaptation of complex typed and large sized 3D geo-spatial information in mobile devices. This prototype system can be used to mobile 3D applications with DEM and satellite imagery in near future.

• Current Optics and Photonics
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• v.4 no.6
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• pp.545-550
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• 2020

We propose a hole-filling method to solve discontinuous depth representation and to reduce the visible seams and cracks that cause the limitation of the viewing angle of the three-dimensional (3D) image in the multilayer type 3D display system. The occlusion and the disocclusion regions between layers, such as the visible seams and cracks, are a major bottleneck of the multilayer type 3D display system to represent a volumetric 3D image by stacking multiple images. As a result, in the reconstructed 3D image, the visible seams and cracks appear as brighter overlapping and undesirable cut-off. In order to resolve the problems above, we applied the depth-fused effect to the sub-depth map generating algorithm and improve the viewing characteristics of the multilayer type 3D display. The experimental demonstrations are also provided to verify the proposed scheme.

• Journal of The Korean Digital Architecture Interior Association
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• v.10 no.3
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• pp.11-18
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• 2010

Cost estimation through fast and correct quantity take offs are crucial in the process of construction project. The existing methods for cost estimation are mainly based on 2D-based drawings and the estimation result tends to be different according to the estimator's experience, the quality and quantity of used information and estimation time. To solve these problems, the domestic construction industry have recently tried to use the data extracted from 3D data modeling based on BIM(Building Information Modeling) in order to achieve more accurate and objective cost estimation. However it tends to increase dramatically the quantity of information that can be used in cost estimation by estimators. Therefore in order to achieve quality information data from 3D data modeling, the characteristics of the project should be reflected on the 3D model and it is most important to extract information only for cost estimation from the whole 3D model fast and accurately. Thus this study aims to propose the 3D modeling method through Data Normalization which maximizes the usability of 3D Data modeling in cost estimation process.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.113-118
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• 2010

Recently, 3D-reconstruction for geographic information and study of geospatial information is progressing in various fields through national policy such as R&D business and pilot project. LiDAR system has a advantage of acquisition the 3D information data easily and densely so that is used in many different fields. Considering to characterist of the point data formed with 3D, it need a high specification CPU because it requires a number of processing operation for 2D form expressed by monitor. In contrast, 2D grid structure, like DEM, has a advantage on costs because of simple structure and processing speed. Therefore, purpose of this study is to solve the problem of requirement of more storage space, when LiDAR data stored in forms of 3D is used for 3D-geographic and 3D-buliding representation. Additionally, This study reconstitutes 2D-gird data to supply the representation data of 3D-geographic and presents the storage method which is available for detailed representation applying tree-structure and reduces the storage space.

• Korean Journal of Computational Design and Engineering
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• v.11 no.6
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• pp.412-421
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• 2006

Recently, the needs for sharing and exchanging drawing information between 2D and 3D data in complex facilities are well recognized throughout the construction industries. The purpose of this study is to propose an information framework to represent 3D IFC (Industry Foundation Classes) -based drawing of building services in complex facilities as 2D drawing. In this study, 1) attributes of building service objects which are used in 3D CAD system are analyzed and present drawing standards are analyzed, 2) based on the analysis, an information framework is developed to represent 3D model in 2D representation, and 3) further more, to test a compatibility of the information sharing framework, number of standardized APIs and an IFC2Dbrowser are developed during the study.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05a
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• pp.409-412
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• 2003

The 3-D shape use to effect of movie, animation, industrial design, medical treatment service, education, engineering etc... But it is not easy to make 3-D shape from the information of 2-D image. There are two methods in restoring 3-D video image through 2-D image; First the method of using a laser; Second, the method of acquiring 3-D image through stereo vision. Instead of doing two methods with many difficulties, I study the method of simple 3-D image in this research paper. We present here a simple and efficient method, called direct calibration, which does not require any equations at all. The direct calibration procedure builds a lookup table(LUT) linking image and 3-D coordinates by a real 3-D triangulation system. The LUT is built by measuring the image coordinates of a grid of known 3-D points, and recording both image and world coordinates for each point; the depth values of all other visible points are obtained by interpolation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.695-696
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• 2021

최근 다양한 연령층과 직업군들 사이에서 기능성 신발에 대한 관심이 증대되고 있다. 그러나 기능성 신발 및 맞춤형 신발은 높은 가격대와 긴 제작 시간이 필요하다. 이러한 문제점은 3D 스캐너 도입으로 해결이 가능하나, 정확한 발 형상 측정이 가능한 3D 스캐너는 고가의 장비이기 때문에 매장별 보급이 어렵다. 본 논문은 기능성 신발의 보급을 위하여 저가형 3D 스캐너에서 정확한 발 고유 변인을 측정할 수 있는 시스템에 대해 서술한다. 이를 위해 이를 위해 저가형 Depth Camera를 이용한 저가형 3D 스캐너의 발 형상 3D 점군 데이터를 2차원으로 변형하고, 발 형태를 감싸는 최소 사각형(Min Area Rect)를 형성하여 발 안쪽점 및 발 가쪽점을 추정한다. 생성된 최소 사각형과 발 안쪽점 및 발 가쪽점 등은 발 고유 변인 측정의 기준이 된다. 실험 결과에서는 측정 기준을 이용하여 발 고유 변인인 발 길이, 발 너비, 발꿈치 너비, 발꿈치에서 발안쪽점 및 발 가쪽점 길이 등 5가지 고유 변인을 측정하는 것을 보여준다.