• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.891-895
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• 1995

This paper describes a solid modeling system based on a systematic description of techniques for analyzing and understanding on engineering drawings. Main stress is placed on clarifying the difference between the drawing understanding and the drawing recognition. The former, in which we feel major interest, is intrinsically a difficult problem because it inherent contains combinatorial search to require more than polynomial time. Actually, understanding drawings is regarded as a process to recover the information lost in projection 3-D objects to 2-D drawings. But, solid modeling by automatic understanding of the given drawings is one of the promising approach, which is described precisely in the text. Reviewing the studies performed so far, we summarize the future direction of the project and inevitable open problems left.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.470-475
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• 2008

Building Information Modeling(BIM) is rooted in the economic and functional advantages of maturing from paper-based 2D drawings. The paper-based design and construction drawings are typical production from BIM and using the drawing under BIM environment is needed because there is not an alternative media instead of paper-based drawings. However using the 2D drawing process based on 2D CAD for BIM environment directly has difficulties because there are significant differences in data structure between CAD and BIM. CAD is based on traditional drawings as a whole while BIM is focused on individual objects and providing various levels of information associated with the objects. It can be an obstacle to move from 2D CAD to BIM that we don't have a standard or guideline for BIM. Futhermore, the complexity of drawing in representation would be the obstacle too, so the solution is discussed in the research based on the case of Samoo Architects and Engineers.

• Journal of KIBIM
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• v.7 no.4
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• pp.8-20
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• 2017

When it comes to set up the BIM through the reverse engineering, the level of detail(LoD) required for finalized outcomes is different from each purpose. Therefore, it is necessary to establish some concrete criteria which describe the definition of LoDs on 3D modeling for the purpose of each reverse engineering. This research shows the criteria of the 1) positional accuracy, 2) generalization level, 3) scale level, 4) scope of description, and 5) the area available for application by classifying LoD from 1 to 6 on 3D modeling for each purpose of reverse engineering. Moreover, through applying those criteria for the 3D point cloud dataset of building made by terrestrial LiDAR, this research finds out the working hour of 3D modeling of reverse engineering by each LoDs according to defined LoD criteria for each level. It is expected that those findings, how those criteria of LoD on reverse engineering are utilized for modeling-workers to decide whether the outcomes can be suitable for their budget, applicable fields or not, would contribute to help them as a basic information.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.68-73
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• 1999

Generally, most of machining processes are done according to the dimention of the draft made by CAD. However, there are many cases that a sample is given without the draft because of the simplicity of the shape in the machining of 2D objects. To cut the same shape as the given sample, this paper proposes the method to extract the geometric information about a large sample using the robot vision and to draw the demensional draft for the machining. Because the resolution of one frame in the vision system is too low, it is necessary to set up a camera according to the desired resolution and to capture the image moving along the contour. And the overall outline can be compounded of the sequentially captured images. In the experiment, we compared the product after the cutting with the original sample and found that the size of two objects was coincided within the allowed error bound.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.43-44
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• 2009

3D bridge information models for a concrete box-girder bridge were built and a typical application example for the estimation linked with the 3D models was proposed. 3D geometry objects with PBS (product breakdown structure) were constructed using standard classification codes and 2D drawings. Information on the amount of materials according to the classification codes was utilized for the estimation system. A process for the estimation of concrete and rebars was developed and verified through the pilot test. Optimization of rebar fabrication was suggested as an additional function and was utilized for the cost reduction and standard fabrication.

• Korean Journal of Construction Engineering and Management
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• v.22 no.3
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• pp.40-51
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• 2021

MLS (Mobile Laser Scanning) which is a scanning method done by moving the LiDAR (Light Detection and Ranging) is widely employed to capture indoor PCD (Point Cloud Data) for floor plan generation in the AEC (Architecture, Engineering, and Construction) industry. The movement and rotation of LiDAR in the scanning phase cause deformation (i.e. skew) of PCD and impose a significant impact on quality of output. Thus, a de-skewing method is required to increase the accuracy of geometric representation. De-skewing methods which use position and pose information of LiDAR collected by IMU (Inertial Measurement Unit) have been mainly developed to refine the PCD. However, the existing methods have limitations on de-skewing PCD without IMU. In this study, a novel algorithm for de-skewing 2D PCD captured from MLS without IMU is presented. The algorithm de-skews PCD using scan matching between points captured from adjacent scan positions. Based on the comparison of the deskewed floor plan with the benchmark derived from TLS (Terrestrial Laser Scanning), the performance of proposed algorithm is verified by reducing the average mismatched area 49.82%. The result of this study shows that the accurate floor plan is generated by the de-skewing algorithm without IMU.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.169-176
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• 1998

Recently, the volume of transportatin is higher by increasing rapid development and human or material interchange among districts. So, the importance of maintenance and management on existing road is come to the fore. In this study, we'd like to build prototypic Road Information Management System to keep road scientifically and efficiently on general road. We built the database of information about a drawing and register on ex-siting road using GSIS. So, we can offer information rapidly and accurately in road maintenance and management service through the query, update and statistic analysis function on road facility as well as AM.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.3-11
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• 2014

Recently, rapid urbanization has necessitated continuous updates in digital map to provide the latest and accurate information for users. However, conventional aerial photogrammetry has some restrictions on periodic updates of small areas due to high cost, and as-built drawing also brings some problems with maintaining quality. Alternatively, this paper proposes a scheme for efficient and accurate update of digital map using point cloud data acquired by Terrestrial Laser Scanner (TLS). Initially, from the whole point cloud data, the building sides are extracted and projected onto a 2D image to trace out the 2D building footprints. In order to register the footprint extractions on the digital map, 2D Affine model is used. For Affine parameter estimation, the centroids of each footprint groups are randomly chosen and matched by means of a modified RANSAC algorithm. Based on proposed algorithm, the experimental results showed that it is possible to renew digital map using building footprint extracted from TLS data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.331-342
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• 1998

본 연구에서는 공간정보를 활용한 전산망 관리시스템을 개발하고자 한다. 이 시스템은 Spatial Data Manager, Network Manager, 3D Viewer 세 부분으로 구성되었다. Spatial Data Manger는 공간상의 Network 장비 및 각종 시설물의 위치와 속성정보를 보여준다. 속성정보 중에서 IP(Internet Protocol)정보는 Network Manager와 연결된다. Network Manager는 ICMP(Internet Control Message Protocol)를 사용하여 네트워크 상태를 파악한다. 3D Viewer는 사용자가 원하는 위치 및 방향에서 시설물을 볼 수 있도록 한다. Spatial Data Manager의 좌표는 3D Viewer의 Camera 좌표와 연동하여 사용자가 원하는 지역을 동시에 2차원과 3차원형태로 볼 수가 있다. 기존 전산망 관리시스템이 단지 수치적으로 네트워크의 상태에 관한 정보를 보여주던 것에 비하여, 개발된 시스템은 공간 위치를 같이 보여줌으로써 누전, 누수 등과 같이 다른 시설물이 전산망에 미칠 수 있는 영향과 전산망 케이블의 종류에 따라 다른 길이의 제약에 따른 영향 등을 분석할 수가 있다. 또한 다른 시설물의 도면 및 시설물에 관련된 기타 정보를 빠르게 검색할 수 있으므로 전산망관리 뿐만 아니라 통합적인 관리를 할 수 있다. 이를 통해 전산망 관리비용을 줄일 수 있을 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2D
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• pp.171-179
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• 2010

The purpose of the present study is to suggest composing the graph topology of sketch drawing element and the recognition of the shape pattern for the earthwork quantity calculation. The algorithm which can extract the topology element such as vertex, edge, face and establish the relation between each topology was developed. The model which can define earthwork graph and recognize the shape pattern of earthwork was presented. As a result of the study, the shape pattern of earthwork that can't be calculated by existing earthwork calculation program could be recognized as expanding this model. The earthwork shape recognition automation using the graph topology model can be applied to the automation for the earthwork quantity estimation.