• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.382-387
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• 2004

As the increasing needs in the industrial filed, many studies for the 3D CAD system are carried out. There are two types of 3D CAD system. One is manifold modeler, the other is non-manifold modeler. In the manifold modeler only 3D objects can be modeled. In the non-manifold modeler 3D, 2D, 1D, and 0D objects can be modeled in a unified data structure. Recently there are many studies on the non-manifold modeler. Most of them are focused on finding unknown topological entities and representing all kinds of topological entities found. In this paper, efficient data structure is selected. The boundary information on a face and an edge is included in this data structure. The boundary information on a vertex is excluded considering the frequency of usage. Because the disk cycle information is not required in most case of modeling. It is compact. It stores essential non-manifold information such as loop cycle and radial cycle. A suitable Euler-Poincare equation is studied and selected. Using the efficient data structure and the selected Euler-Poincare equation, 18 basic Euler operators are implemented. Several 3D models are created using the implemented modeler. A non-manifold modeling can be carried out using the implemented 3D CAD system. The results of this paper could be used in the further studies such as an implementation of Boolean operators, and a translation of 2D CAD drawings to 3D models.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.5
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• pp.747-754
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• 2002

We propose a Web-based collaborative CAD system which is independent from any platforms, and develop a 3D solid modeler in the system. We developed a new prototype of 3D solid modeler based on the web using Java 3D API, which could be executed without any 3D graphics software and worked collaboratively interacting with each user. The modeler can create primitive objects and get various 3D objects by using loader. The interactive control is available to manipulate-objects such as picking, translating, rotating, zooming. Users connect to this solid modeler and they can create 3D objects and modify them as they want. When this solid modeler is imported to collaborative design system, it will be proved its real worth in today's CAD system. Moreover, if we improve this solid modeler adding to the 3D graphic features such as rendering and animation, it will be able to support more detail design and effect view.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.744-747
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• 2008

Quantity information focused on a design drawing plays a critical role in a decision making related to cost for project participants during project life cycles. Related participants absolutely depend on quantity take-off working which produces the quantity information by hand, and then a worker's mistake often causes many errors. The difference of quantity by the know-how of the person in charge of the estimation also occurs. In addition, the worker passes through the whole quantity take-off processes again in case of re-working for quantity take-off produced by a change order. The requirements about the automated estimation increase because of the needs for the accurate quantity take-off and dealing with the change order and recently, the studies about the automated estimation working process based on 34 cad model from 3d cad modeler are attempted in various viewpoints. However, the existing studies reach the limits such as common quantity data type framework for getting Quantity information. Focused on a certain 34 cad modeler and BIM based automation of estimation using it Therefore, the objective of this study is to develop the a series of system which can extract, analyze, and verify Quantity Data Type in modeler to automate quantity take-off originated from various 3d cad modelers as a foundation study for BIM based automation of estimation framework.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.233-240
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• 2000

We designed a 3D solid modeler based on the web, which was independent from platforms, which could be executed without 3D graphics softwares. In this paper, we show the design of system libraries and how to implement in Java 3D. A client connects to the solid modeler server, design solid model, stores the data as the various file format, and displays the data from other CAD systems. This solid modeler can support the detail design as 3D graphics features such as viewing, rendering, animating are available.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.150-157
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• 1996

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interfer- ence check between solids, the structural design of machine tools and robots and so on.

• Korean Journal of Computational Design and Engineering
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• v.10 no.4
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• pp.293-302
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• 2005

The research focused quantitative comparisons of protocols occurring in the architectural massing process using two different tools, three-dimensional(3D) modeler and traditional design tools, to aid architectural massing education. Through the protocol analysis from some experiments, the research identified the following conclusions: 1) Usage of traditional tools produced much higher protocol rate in proposing solution, evaluating proposed solution, explicitness of strategies. This result seemed to be from convenience of traditional tools causing faster visual cognitive cycle. 2) Usage of 3D modeler produced much higher protocol rate concerning attempts of making design vocabulary. The result indicated 3D modeler has relatively effective functions for mass generation and orientation, however it still has some weaknesses on display interface which cause designer's lower idea generations compared to traditional design tools.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.371-376
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• 2004

This study presents a way to generate and manage engineering information by applying steel bridge information model with 3D shape to existing application program. ACIS solid modeling kernel is used to visualize 3D geometric shape of steel bridge on the AutoCAD program. The shape information of 3D solid model can be connected to structural design information of steel bridge by an application module based on information model. The application module for manipulating steel bridge information can be easily developed by ObjectARX programming library supporting functional expansion of AutoCAD program. End-users can use the application module without any additional environmental setup on the AutoCAD. Thus this study facilitates information management of steel bridge by using ACIS solid modeler and ISO/STEP methodology.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.689-694
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• 1994

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interference check between solids, the structural design of machine tools and robots and so on.

• CDE review
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• v.5 no.3
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• pp.48-50
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• 1999

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.912-920
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• 2002

As computer systems and communication technologies develop rapidly, CSCW(Computer Supported Collaborative Work) system appears nowadays, through which it is available to work on virtual space without any restriction of time and place. Most of CWCS systems depend on a special network and groupware. The systems of graphics and CAD are not so many because they are specified by hardware and application software. We propose a Web-based collaborative CAD system which is independent from any platforms, and develop a 3D solid modeler in the system. This system can be worked in the environment of Client/Server architecture. Clients connect to the design server through Java applet on WWW. The server is implemented by Java application.