• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.241-246
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• 2013

From the numerical results of density-based topology design optimization, a CAD geometric model is constructed and fabricated using 3D printer to experimentally validate the optimal design. In the process of topology design optimization, we often experience checkerboard phenomenon and complicated branches, which could result in the manufacturing difficulty of the obtained optimal design. Sensitivity filtering and morphology methods are used to resolve the aforementioned issues. Identical volume fraction is used in both numerical and experimental models for precise validation. Through the experimental comparison of stiffness in various designs including the optimal design, it turns out that the optimal design has the highest stiffness and the experimental result of compliance matches very well with the numerical one.

• Tunnel and Underground Space
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• v.24 no.3
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• pp.234-242
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• 2014

Deep drilling project should be managed systematically and efficiently because it is significantly influenced by various related factors having uncertainty and high risk in terms of economy and effective management. In particular, drilling project involves participants from various sectors including necessary service company and it also needs their collaboration by sharing related information occurring at drilling process in order to secure efficient performance management. We developed 4D (3D + time) information based visualization system for progress management by combining 3D design model and predicted optimized control parameters for each section in geothermal well design. We also applied PDM (precedence diagramming method) to the system in order to setup the effective process model and hooked it up to 3D information based on precedence relation and required time for informatized process network.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.247-249
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• 2002

최근 3D 공간 객체의 효율적인 표현을 위해, 3D 연산 및 다차원 인덱싱 기법에 관한 연구가 활발히 진행되고 있다. 또한 이러한 인덱스나 연산을 기반으로 많은 응용프로그램들이 개발되고 있다. 그러나, 대부분의 응용프로그램들은 단순히 비공간 속성에 대한 질의를 기반으로 한 3D 객체의 시각화에만 치중하고 있기 때문에, 3D 공간 객체에 관한 분석 기능을 제대로 지원하지 못하고 있다. 따라서, 이 논문에서는 3D 공간 객체에 관한 효율적 분석 기능을 제공할 수 있는 3D 공간 연산 처리기를 설계 및 구현하였다. 기존 시스템과의 상호운용을 위해서, 제안한 연산 처리기는 OpenGIS의 2차원 기하 객체 모텔을 3차원으로 확장한 3D 기하 객체 모델을 기반으로 하였다. 또한 빠른 공간 연산을 수행하기 위해 인덱스와 연동하여 구현하였다. 이 연산 처리기는 3D GIS에 적용될 경우, 효율적인 공간 분석 기능을 제공할 수 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.2
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• pp.102-114
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• 2004

The present work has been developed the interpretation processor including the behavior of material failure and the separation phenomena under transient dynamic loading (the operation of explosive bolt) using AUTODYN V4.3, SoildWork 2003 and TrueGrid V2.1 programs. It has been demonstrated that the interpretation in ridge-cut explosive bolt under dynamic loading condition should be necessary to the appropriate failure model and the basic stress of bolt failure is the principal stress. The use of this interpretation processor developing the present work could be extensively helped to design the shape and the amount of explosives in the explosive bolt having a complex geometry. It is also proved that the interpretation processor approach is an accurate and effective analysis technique to evaluate the separation mechanism in explosive bolts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7204-7210
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• 2015

This paper has developed the system for supporting the approximate construction cost and the quantity estimation based on 3D model information in the pre-project planning phase of 3-span continuous cable-bridge with 2-pylons. First of all, we'd analyzed the design information (structural design report, blueprint and quantity) of the existing cable-stayed bridges and derived the design variables of cable-stayed bridges. We developed the BIM wizard that generates a cable-stayed bridge model parametrically based on derived design variables. The principle material quantities of cable-stayed bridge are calculated directly from 3-dimensional bridge model built by using the BIM wizard. Then, we can estimate the construction cost in relation to its quantities and unit cost of cable-stayed bridge. In a result, we have established the system that the construction cost can be estimated more specific than the conventional method (construction estimates per meter or square meter). We hereby will be able to review various alternatives as soon as possible in bidding process.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.385-394
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• 1999

제품을 설계하는 디자이너나 엔지니어는 많은 시간과 노력을 들이지 않고서 그들이 설계한 3차원 제품 모델에 대한 사실적인 이미지를 원한다. 디자인 프로세스의 초기인 개념 설계에서부터 설계검증, 그리고 가공 과정에서 사실적인 이미지가 매우 유용하므로, 대부분의 주요 CAD 제작사는 그들의 CAD 소프트웨어에 고급 렌더링 기능을 추가하고 있다. 상용의 CAD/CAM 모델러에서는 NURB 곡면을 기초로 모델링을 수행하므로, NURB 곡면을 렌더링할 수 있는 패키지가 필요하다. VIF(Visual InterFace) 렌더링 라이브러리는 A-buffer 방식과 Ray tracing 방식의 두 가지 고급 렌더링 모드를 제공한다. 다각형은 물론 NURB 곡면을 입력으로 받아 사용자가 설정한 표면의 각종 계수, 원하는 view와 설정된 광원에 따라 이미지를 만들고 다양한 형태로 출력시킬 수 있는 다양한 기능을 제공한다. 본 논문에서는 VIF 렌더링 라이브러리에 대한 구조와 기능별로 분류된 함수에 대하여 설명하며, 실제로 CAD/CAM 시스템과 통합되어 구상설계에서부터 3차원 설계 모델링에 이르기까지의 제조공정에서 설계검증 툴로써 어떻게 활용되고 있는가에 대하여 기술한다.Abstract Engineers and industrial designers want to produce a realistic-looking images of a 3D model without spending a lot of time and money. Photo-realistic images are so useful from the conceptual design, through its verification, to the machining, that most major CAD venders offer built-in as well as add-on photo-realistic rendering capability to their core CAD software. Since 3D model is consists of a set of NURB surfaces in commercial CAD packages, we need a renderer which handles NURB surface as well as other primitives.A new rendering library called VIF (Visual InterFace) provides two photo-realistic rendering modes: A-buffer and Ray tracing. As an input data it takes NURB surfaces as well as polygonal data and produces images in accordance with the surface parameters, view and lights set by user and outputs image with different formats. This paper describes the overall architecture of VIF and its library functions classified by their functionalities, and discusses how VIF is used as a graphical verification tool in manufacturing processes from the conceptual design to 3D modeling.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.434-440
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• 2013

Generally, the envelope of a freeform building is composed of a structure made with rectangular or C-shaped steel pipe, and steel or aluminum panel finishes on the structure. However, these construction methods increase material loss and cost and time. There are also numerous cases of misunderstanding of design and difficulties in construction, which frequently cause construction errors. Such construction errors decrease construction productivity, resulting in poor construction quality and the need for rework, as well as cost and time overruns. To solve the problem, this study proposes a 3D coordinate control technology for freeform structure implemented through a CNC(Computerized Numerical Control) Twisted tube method, and by extension, develops a BIM-based envelope construction method for freeform building.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.285-288
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• 2010

유체저장탱크가 외부로부터 지진과 같은 동적하중을 받게 될 경우 유체와 구조물의 상호작용(Fluid-Structure Interaction)으로 인하여 일반적인 구조물과는 상이한 거동을 보이게 된다. 이러한 복잡한 상호작용을 고려하여 현재 내진 설계에서는 Housner와 Haroun의 이론을 적용한 단순화 모델들이 사용되고 있다. 이들 모델은 유체의 거동을 대류(convective) 성분과 충격(impulsive) 성분으로 구분하여 집중질량으로 단순화 한다. 하지만 점차 대형화되고 있는 유체저장탱크의 정확한 동적 거동 특성을 파악하고, 지진하중과 같은 방향성을 가진 하중에 대한 구조물의 정확한 응답을 해석하려면 단순화 모델의 적용성 검토가 필요하다. 본 연구에서는 지진하중을 받는 유체저장탱크의 동적거동을 집중질량 모델과 3차원 모델을 이용하여 해석하였다. 나아가 해석결과의 차이를 분석하여 단순화 모델의 정확도 향상을 위한 내진설계변수 산출에 관하여 향후 연구방향을 제시하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.4
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• pp.245-252
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• 2021

Underground facilities were constructed as needed by various management organizations, the result of which was the disordered and scattered underground spaces. This phenomenon can be viewed as the main cause of safety accidents in the underground space. To solve this problem, research on systematic construction and management of underground facilities should be conducted. Therefore, to improve the accuracy and the quality of information and to facilitate the systematic construction and management of underground facility information, this study aims to establish a 3D data model that conforms to international spatial information standards for pipeline underground facilities and to implement the data model to enable visualization. The result of this study can be used to improve the consistency of information not only between underground facilities, but also the correspondence between above ground and underground facilities. As such, this study has academic significance in that it presents an integrated data model that includes various objects in the ground and underground spaces and enables interoperability between diverse domain data.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.247-252
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• 2008

Recently, the virtual construction system in which project participants efficiently share and control the information throughout the life-cycle of construction project using 3D object models is being developed all over the world. In this paper, a design of interface between 3D object model of structures and structural analysis system that is essential for the analysis and design of civil structures in the virtual space is treated. The relation parametric modeling technique that is needed to make the 3D object models and the construction method of product breakdown structure(PBS) that considers the several parameters for the structural analysis are presented. PBS is built so that it is possible to extract needed attribute information from 3D object model and to apply it to the structural analysis. Design methodology for interface program is proposed that several numerical values determined by the cooperative work same as structural analysis are delivered to 3D object models without additional work. An interface program between 3D object models and structural analysis system developed based on the proposed method would be effectively used to develop virtual construction system.