• Title/Summary/Keyword: 3D spatial object

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Constraint Relaxation using User Interaction in Reactive Scheduling Environment (동적 스케줄링 문제에서 사용자 상호작용을 이용한 제약조건 완화)

  • Lee, Hoon;Jung, Jong Jin;Jo, Geun Sik
    • Journal of Advanced Navigation Technology
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    • v.2 no.2
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    • pp.132-142
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    • 1998
  • In optical scanning holography, 3-D holographic information of an object is generated by 2-D active optical scanning. The optical scanning beam can be a time-dependent Gaussian apodized Fresnel zone plate. In this technique, the holographic information manifests itself as an electrical signal which can be sent to an electron-beam-addressed spatial light modulator for coherent image reconstruction. This technique can be applied to 3-D optical remote sensing especially for identifying flying objects. In this paper, we first briefly review optical scanning holography and analyze the resolution achievable with the system. We then present mathematical expression of real and virtual image which are responsible for holographic image reconstruction by using Gaussian beam profile.

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Analysis of the Status of Mine and Methods of Mine Geospatial Information Construction Technology for Systematic Mine Management (체계적인 광산관리를 위한 광산현황 및 광산공간정보 구축 기술 분석)

  • Park, Joon-Kyu;Lee, Keun-Wang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.355-361
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    • 2018
  • Mining is important as a national key industry that supplies energy and raw materials that are the basis for industrial development. On the other hand, mine development is necessarily accompanied by mineralization, for example, ground subsidence, heavy metal pollution, and water pollution. The mine hazard has a large range of damage, and it takes much time and cost to recover. In addition, there is a need for systematic mining management in order to prevent damages from occurring continuously. In this study, the present status of domestic mining industry and geospatial information construction technology for mining management were investigated. 95% of the mines surveyed were nonmetallic, and limestone mines accounted for 67%, and the constructed mine spatial information is not constructed with 3D geospatial information due to 2D current status, section, and geological map. Considering the results of the survey and analysis of 3D laser scanner and characteristics of Korean mine, handheld scanner is considered to be the most suitable method for constructing mine geospatial information. In addition, the data acquired through the 3D laser scanner can effectively visualize the object, and it can contribute to the systematic management of mining because it can be used for various purposes such as generation of drawings and calculation of volume.

Comparison of Open Source based Algorithms and Filtering Methods for UAS Image Processing (오픈소스 기반 UAS 영상 재현 알고리즘 및 필터링 기법 비교)

  • Kim, Tae Hee;Lee, Yong Chang
    • Journal of Cadastre & Land InformatiX
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    • v.50 no.2
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    • pp.155-168
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    • 2020
  • Open source is a key growth engine of the 4th industrial revolution, and the continuous development and use of various algorithms for image processing is expected. The purpose of this study is to examine the effectiveness of the UAS image processing open source based algorithm by comparing and analyzing the water reproduction and moving object filtering function and the time required for data processing in 3D reproduction. Five matching algorithms were compared based on recall and processing speed through the 'ANN-Benchmarks' program, and HNSW (Hierarchical Navigable Small World) matching algorithm was judged to be the best. Based on this, 108 algorithms for image processing were constructed by combining each methods of triangulation, point cloud data densification, and surface generation. In addition, the 3D reproduction and data processing time of 108 algorithms for image processing were studied for UAS (Unmanned Aerial System) images of a park adjacent to the sea, and compared and analyzed with the commercial image processing software 'Pix4D Mapper'. As a result of the study, the algorithms that are good in terms of reproducing water and filtering functions of moving objects during 3D reproduction were specified, respectively, and the algorithm with the lowest required time was selected, and the effectiveness of the algorithm was verified by comparing it with the result of 'Pix4D Mapper'.

Enhancing Query Efficiency for Huge 3D Point Clouds Based on Isometric Spatial Partitioning and Independent Octree Generation (등축형 공간 분할과 독립적 옥트리 생성을 통한 대용량 3차원 포인트 클라우드의 탐색 효율 향상)

  • Han, Soohee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.5
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    • pp.481-486
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    • 2014
  • This study aims at enhancing the performance of file-referring octree, suggested by Han(2014), for efficiently querying huge 3D point clouds, acquired by the 3D terrestrial laser scanning. Han's method(2014) has revealed a problem of heavy declining in query speed, when if it was applied on a very long tunnel, which is the lengthy and narrow shaped anisometric structure. Hereupon, the shape of octree has been analyzed of its influence on the query efficiency with the testing method of generating an independent octree in each isometric subdivision of 3D object boundary. This method tested query speed and main memory usage against the conventional single octree method by capturing about 300 million points in a very long tunnel. Finally, the testing method resulted in which twice faster query speed is taking similar size of memory. It is also approved that the conclusive factor influencing the query speed is the destination level, but the query speed can still increase with more proximity to isometric bounding shape of octree. While an excessive unbalance of octree shape along each axis can heavily degrade the query speed, the improvement of octree shape can be more effectively enhancing the query speed than increasement of destination level.

Effect of Photographing Light Intensity on Rock Joint Survey in Mine Tunnels using Stereophotogrammetry (입체사진측량기법을 이용한 광산 갱도 내 불연속면 조사에 대한 조도의 영향에 관한 연구)

  • Han, Jeong-Hun;Song, Jae-Joon;Jo, Young-Do
    • Tunnel and Underground Space
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    • v.19 no.6
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    • pp.517-525
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    • 2009
  • Stereophotogrammetry is used to extract spatial information of an interested object by constructing a stereo-image from two or more photos. In this study, the stereophotogrammetry was adopted for a rock joint survey in mine tunnels. The orientations of discontinuities were measured from two mine tunnels with a clinocompass. To evaluate the effect of photographing light level on the stereophotogrammetry analysis, the light intensity was changed within a predefined range for every photograph. Those photographs were analyzed by using a commercial code for stereophotogrammetry - ShapeMetriX 3D, and the results from the analysis were compared with the manual measurement using a clinocompass.

A Study on Shape Measurement by Using Electronic Speckle Pattern Interferometry (전자 스페클 패턴 간섭법을 이용한 형상 측정에 관한 연구)

  • 강영준;김계성
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.10
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    • pp.156-164
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    • 1998
  • Electronic Speckle Pattern Interferometry(ESPI) has been used to measure surface deformations of engineering components and materials in industrial areas. ESPI, a non-contact and non-destructive technique, is capable of providing full-field results with high spatial resolution and high speed. One of the important application using electronic speckle pattern interferometry is electronic speckle contouring of a diffused object for 3-D shape analysis and topography measurement. Generally the electronic speckle contouring is suitable for providing measurement range from millimeters to several centimeters. In this study, we introduce the contouring method by modified dual-beam speckle pattern interferometer and the shift of the two illumination beams through optical fiber in order to obtain the contour fringe patterns. We also describe formation process of depth contour fringes and grid contour fringes by shifting direction of the two illumination beams. Before the experiments, we performed the geometric analysis for dual-beam-shifted ESPI contouring, and then, the electronic speckle contouring experiment with various specimens. For quantitative analysis of the contour fringes, we used 4-frame phase shifting method with PZT Finally, good agreement between the geometric analysis and experimetal results is obtained.

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Current Status of Geo-referenced Contents and a New Street Level Contents (공간정보 콘텐츠의 현황 및 새로운 거리 수준 콘텐츠)

  • Yoon, Bo Ram;Choi, Kyoung Ah;Lee, Im Pyeong
    • Spatial Information Research
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    • v.22 no.6
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    • pp.91-103
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    • 2014
  • The high popularity of geo-referenced mash-up improves the quality and availability of geo-referenced contents. Such contents which accurately represent the real world in street level as well as in aerial level have appeared. Despite the advent of geo-referenced contents of street level, it is still hardly used for mash-up. In this study, we thus find out its obstacles to spatial mash-up and solutions to overcome them to activate the mash-up based on street level contents. By analyzing the current geo-referenced content with respect to its spatial scope and the way of representation, we draw the limitations of current street level contents. Furthermore, we propose the 'new media geo-referenced content' as a solution to overcome those limitations. With 'new media geo-referenced content', it is able to determine the 3D coordinates of given object in real world. Using those coordinates, database linkage can be more closer, flexible and organic. Such 'new media geo-referenced content' can contribute to activation of geo-referenced contents in street level and its mash-up.

Training Performance Analysis of Semantic Segmentation Deep Learning Model by Progressive Combining Multi-modal Spatial Information Datasets (다중 공간정보 데이터의 점진적 조합에 의한 의미적 분류 딥러닝 모델 학습 성능 분석)

  • Lee, Dae-Geon;Shin, Young-Ha;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.2
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    • pp.91-108
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    • 2022
  • In most cases, optical images have been used as training data of DL (Deep Learning) models for object detection, recognition, identification, classification, semantic segmentation, and instance segmentation. However, properties of 3D objects in the real-world could not be fully explored with 2D images. One of the major sources of the 3D geospatial information is DSM (Digital Surface Model). In this matter, characteristic information derived from DSM would be effective to analyze 3D terrain features. Especially, man-made objects such as buildings having geometrically unique shape could be described by geometric elements that are obtained from 3D geospatial data. The background and motivation of this paper were drawn from concept of the intrinsic image that is involved in high-level visual information processing. This paper aims to extract buildings after classifying terrain features by training DL model with DSM-derived information including slope, aspect, and SRI (Shaded Relief Image). The experiments were carried out using DSM and label dataset provided by ISPRS (International Society for Photogrammetry and Remote Sensing) for CNN-based SegNet model. In particular, experiments focus on combining multi-source information to improve training performance and synergistic effect of the DL model. The results demonstrate that buildings were effectively classified and extracted by the proposed approach.

A Study on Light-weight Algorithm of Large scale BIM data for Visualization on Web based GIS Platform (웹기반 GIS 플랫폼 상 가시화 처리를 위한 대용량 BIM 데이터의 경량화 알고리즘 제시)

  • Kim, Ji Eun;Hong, Chang Hee
    • Spatial Information Research
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    • v.23 no.1
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    • pp.41-48
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    • 2015
  • BIM Technology contains data from the life cycle of facility through 3D modeling. For these, one building products the huge file because of massive data. One of them is IFC which is the standard format, and there are issues that large scale data processing based on geometry and property information of object. It increases the rendering speed and constitutes the graphic card, so large scale data is inefficient for screen visualization to user. The light weighting of large scale BIM data has to solve for process and quality of program essentially. This paper has been searched and confirmed about light weight techniques from domestic and abroad researches. To control and visualize the large scale BIM data effectively, we proposed and verified the technique which is able to optimize the BIM character. For operating the large scale data of facility on web based GIS platform, the quality of screen switch from user phase and the effective memory operation were secured.

A Hybrid Semantic-Geometric Approach for Clutter-Resistant Floorplan Generation from Building Point Clouds

  • Kim, Seongyong;Yajima, Yosuke;Park, Jisoo;Chen, Jingdao;Cho, Yong K.
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.792-799
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    • 2022
  • Building Information Modeling (BIM) technology is a key component of modern construction engineering and project management workflows. As-is BIM models that represent the spatial reality of a project site can offer crucial information to stakeholders for construction progress monitoring, error checking, and building maintenance purposes. Geometric methods for automatically converting raw scan data into BIM models (Scan-to-BIM) often fail to make use of higher-level semantic information in the data. Whereas, semantic segmentation methods only output labels at the point level without creating object level models that is necessary for BIM. To address these issues, this research proposes a hybrid semantic-geometric approach for clutter-resistant floorplan generation from laser-scanned building point clouds. The input point clouds are first pre-processed by normalizing the coordinate system and removing outliers. Then, a semantic segmentation network based on PointNet++ is used to label each point as ceiling, floor, wall, door, stair, and clutter. The clutter points are removed whereas the wall, door, and stair points are used for 2D floorplan generation. A region-growing segmentation algorithm paired with geometric reasoning rules is applied to group the points together into individual building elements. Finally, a 2-fold Random Sample Consensus (RANSAC) algorithm is applied to parameterize the building elements into 2D lines which are used to create the output floorplan. The proposed method is evaluated using the metrics of precision, recall, Intersection-over-Union (IOU), Betti error, and warping error.

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