• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.2
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• pp.126-131
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• 2004

On-machine automatic measuring software from 3-D solid modeler is generally applied to assess the functional performance of a final produce for computer numerical control (CNC) machine. Automatic measuring software may also be performed on individual components of CNC machine in which some functional aspect of the component must be examined and cannot be implicity determined by means of a mechanical inspection. The manufacturing specialist, combined with the appropriate software simulation, can not only create the commands to drive the virtual measuring but also can check for mistakes by viewing the computer graphics simulation of the tool cutting sequence.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.50-57
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• 2003

In this paper, an automated design and 3-D modeling system of an axial fan and a boss for cooling towers was developed. API and parametric design Provided by a commercial solid-modeler are engaged to automate modeling process. Design data of the boss are assumed to be given by a user with design experiences while the fan from the fan design program using three-dimensional flow analysis. An algorithm avoiding the interferences between fans and a boss is developed. The design data are registered on the database not only to remove duplicate design but also to transfer the data to ERP system.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.1
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• pp.67-78
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• 2005

We proposed a blind watermarking for 3D mesh model using the patch CEGIs. The CEGI is the 3D orientation histogram with complex weight whose magnitude is the mesh area and phase is the normal distance of the mesh from the designated origin. In the proposed algorithm we divide the 3D mesh model into the number of patch that determined adaptively to the shape of model and calculate the patch CEGIs. Some cells for embedding the watermark are selected according to the rank of their magnitudes in each of patches after calculating the respective magnitude distributions of CEGI for each patches of a mesh model. Each of the watermark bit is embedded into cells with the same rank in these patch CEGI. Based on the patch center point and the rank table as watermark key, watermark extraction and realignment process are performed without the original mesh. In the rotated model, we perform the realignment process using Euler angle before the watermark extracting. The results of experiment verify that the proposed algorithm is imperceptible and robust against geometrical attacks of cropping, affine transformation and vertex randomization as well as topological attacks of remeshing and mesh simplification.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.122-126
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• 2008

Integrating a 3D solid modeler with a general purpose FEM code, an automatic stress intensity factor analysis system of the 3D crack problems has been developed. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. Finally, the complete finite element(FE) model generated, and a stress analysis is performed. This paper describes the methodologies to realize such functions, and demonstrates the validity of the present system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.716-719
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• 1997

This paper describes the runner and gate design capabilities of the RAMEDS system, which is a specialized CAD system for injection mold design, dcvcloped using the application procedure interface of the Unigraphics system. In this system, runners lying on sculptuted partlng surface can be modeled by projecting the runner trajectory on the surface and sweeping a selected cross section along the projcctcd trajectory. In addtion, the system provides solid modeling capabilities for three types of gates currently.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.235-238
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• 2000

오늘날 컴퓨터와 통신 기술의 발달로 시간과 공간의 제약 없이 공유된 가상 공간에서 작업을 하는 컴퓨터 지원 협동 시스템이 등장하고 있다. 그러나 그래픽 분야와 CAD시스템은 하드웨어와 응용 소프트웨어에 크게 의존하고 있는 실정이다. 여기에서 제안하는 협동 CAD시스템은 인터넷 망을 통하여 웹 상에서 플랫폼에 구애받지 않고 협동작업이 이루어지도록 하였고, VRML과 Java3D API를 이용하여 쉽게 도형을 생성하고 편집하여 전송하거나 출력 저장할 수 있도록 하며, 채팅을 통해 인터액티브 한 작업이 가능하게 하고 있다. 이 시스템은 클라이언트/서버 구조로 클라이언트는 자바 애플릿을 통해 웹 상에서 접근하고 서버는 자바 애플리케이션으로 접속을 통제하는 접속관리자, 작업 그룹의 동기화를 유지하며 공유작업공간을 확보하는 작업관리자, 그리고 3차원 도형 객체를 생성해 내는 솔리드 모델러로 이루어져 있다.

• Archives of design research
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• v.19 no.4 s.66
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• pp.71-80
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• 2006

Collaboration has become essential in the product design process due to internationalized and specialized business environments. This study presents a real-time collaborative 3D design workspace for distributed designers, focusing on the development and the evaluation of new interaction techniques supporting nonverbal communication such as awareness of participants, shared manipulation and tele-presence. Requirements were identified in terms of shared objects, shared workspaces and awareness through literature reviews and an observational study. An Augmented Reality based collaborative design workspace was developed, in which two main interaction techniques, Turn-table and Virtual Shadow, were incorporated to support shared manipulation and tele-presence. Turn-table provides intuitive shared manipulation of 3D models and physical cues for awareness of remote participants. Virtual shadow supports natural and continuous awareness of location, gestures and pointing of partners. A lab-based evaluation was conducted and the results showed that interaction techniques effectively supported awareness of general pointing and facilitated discussion in 3D model reviews. The workspace and the interaction techniques can facilitate more natural communication and increase the efficiency of collaboration on virtual 3D models between distributed participants (designer-designer, engineer, or modeler) in collaborative design environments.

• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.544-548
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• 1999

This study is about development of Feature-based Solid Modeling system in integrated CAD/CAM environment. Parasolid modeling kernel and HOOPS/3D graphics library was used to develop this system in PC level. System feature library was defined using both procedural and declarative approach method. The raw stock is created by boolean operator using design primitives, and a part is designed that pre-defined feature is removed from the raw stock. This method is called "DSG(Destructive Solid Geometry)" and basic constructive operator of this system. This is not complete system and only the first step to develop Feature-based Solid Modeling System using Parasolid. We will add more powerful functionality and flexible GUI in Windows.n Windows.

• Korean Journal of Construction Engineering and Management
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• v.22 no.4
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• pp.29-40
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• 2021

Recently, interest in Building Information Modeling (BIM) has increased globally, and 3D modeling is a start for the application of BIM at construction sites. However, while many studies have been conducted on the efficiency of 3D modeling focused on civil facilities, there is a lack of research on the earthwork BIM. In particular, since 3D slope often has complex shapes depending on the ground models, the efficiency method for 3D slope are needed. This study analyzed the interfaces and procedures of other software to find out what functions users need. Then the functions to enter intervals between 3D faces, select multiple ground models, and improve the interface are reflected on the developed system and is able to efficiently perform modeling with only five steps, and reduce the number of clicks and inputs. As a result of conducting the test to verify the efficiency, using the developed system made skilled users complete modeling at least 1.8 times faster and unskilled people at least 2.4 times faster than using other software. This is expected to perform 3D slope modeling more efficiently, as well as to contribute to the activation of future BIM adoption for housing construction projects.