• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.3 s.246
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• pp.219-230
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• 2006

Digital CAD models are one of the most important assets the manufacturer holds. The trend toward concurrent engineering and outsourcing in the distributed development and manufacturing environment has elevated the importance of high quality CAD model and its efficient exchange. But designers have spent a great deal of their time repairing CAD model errors. Most of those poor quality models may be due to designer errors caused by poor or incorrect CAD data generation practices. In this paper, we propose a rule-based approach for healing CAD model errors. The proposed approach focuses on the design history data representation from a commercial CAD model, and the procedural method for building knowledge base to heal CAD model. Through the use of rule-based approach, a CAD model healing system can be implemented, and experiments are carried out on automobile part models.

• Korean Journal of Computational Design and Engineering
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• v.16 no.3
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• pp.167-177
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• 2011

This paper describes an ontology-based intelligent CAD system for injection mold design, which has been developed based on a commercial CAD system called Unigraphics and an ontological framework for representing the implicit design knowledge as well as the explicit based on the extended function-behavior-structure (FBS) engineering design model that includes the constraint. The system also provides various convenient solid modeling capabilities for mold design and the design process modeling capability that facilitates mold redesign process.

• Korean Journal of Computational Design and Engineering
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• v.10 no.4
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• pp.244-253
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• 2005

In the initial ship design stage of shipyards, the hull form design, the basic design (compartment modeling and ship calculation), and the hull structural design are being performed by different systems. Thus, the problem on interfaces between these systems occurs. To solve this, we developed the hull form design system 'EzHULL' and the compartment modeling and ship calculation system 'EzCOM-PART' for developing finally an integrated ship design system. And, in this study, we present an object-oriented hull structural design .system 'EzSTRUCT', which is developed recently. A structural design in an initial design stage can be frequently changed, because the design is not firmly determined yet. Therefore, designers perform the simplified structural modeling with bigger structural parts (or objects) such as deck, longitudinal bulkhead, etc. in the initial design stage, and the detailed structural modeling with smaller structural parts such as plate, seam, slot, etc. in the detailed design stage. However, the existing hull structural CAD system used in a shipyard is not efficient in generating a 3D CAD model in the initial design stage, because it has difficulty in handling frequent changes in design. Therefore, designers initially draw 2D drawings in the initial design stage, and generate the 3D CAD model from these 2D drawings in the detailed design and production design stages. In this study, the hull structural design system, which can efficiently generate a 3D CAD model through rapid modeling at an initial design stage, was developed in this study To evaluate the applicability of the developed system, we applied it to hull structural modeling of various ships such as a VLCC, a bulk carrier, etc. As a result, it could efficiently generate a 3D CAD model of a hull structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.724-728
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• 1997

A CAD system of grid element for vacuum fluorescent disply has been developed. In order to reduce design man-houre and human erros, it is used to automate the design process using a knowledge base system. In the case of VFD product design, the most important consideration is the short-life cycle. So the development of CAD system for VFD product is needed. The developed system is based on the knowledge base system which is involved in a lot of expert's technology in the practice field. Using C-language under the HP-UNIX system, CIS customer language of the EXCESS CAD/CAM is used as the overall CAD environment. Results of this system will provide effective aids to the designer in this field

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1146-1149
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• 1995

The CAD/CAM System for deep drawing transfer die in mechanical press proess has been developed. The developed CAD system can generate the drawing of drawing of transfer die in mechanical press. Using these results from CAD system, it can generate the NC data to machine die's elements on the CAD system. This system can reduce design man-hours and human errors. In order to construct the system, it is used to automate the design process using knowledge base system. The developed system is based on the knowledge base system which is involved a lot of expert's technology in the practice filed. Using AutoLISP language under the AutoCAD system, CTK customer language of SmartCAM is used as the overall CAD/CAM environment. Results of this system will be provide effective aids to the designer and mannufacturer in this field.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.720-724
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• 2000

In this paper, we introduce a seamlessly integrated CAD-based design system (DS) for CAD modeling, engineering analysis, and optimal design which has been developed in CCED at KAIST, The key points of this integrating philosophy are to make full use of a parametric CAD program as the platform of integration and to adopt finite difference method for design sensitivity analysis in optimization process to get robustness and versatility. Design variables are directly selected by clicking CAD model parameters and all the analysis and design activities are menu-driven. This integrated program, named as DS/FDM, runs on Windows NT or Unix and FE analyses are performed at a remote Unix-workstation for multiple users. Application examples include shape optimal design of a belt clip that fits onto a portable electronic device and a bracket to show performance of DS/FDM with shell and tetra solid elements. This software is found efficient and effective fur shape design and size design of engineering structures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.723-726
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• 2001

The design of delivery system is one of the most important subject in injection molding. Delivery system is a channel to flow the polymer melt from the injection molding machine to the mold cavities and affect quality and productivity of the part. The synthesis of delivery system of injection molding has been done empirically, since it requires profound knowledge about the moldability and causal effects on the properties of the part, which are not available to designers through the current CAD systems. A knowledge-based CAD system is constructed by adding the knowledge module to an existing geometric modeler and contains knowledge to permit non-experts ad well as mold design experts to generate the acceptable geometries of gate and runner for injection molded parts.

• International Journal of CAD/CAM
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• v.5 no.1
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• pp.83-90
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• 2005

This is a report on a new methodology to manage design knowledge by utilizing a knowledge-based CAD and a prototype system named $C^3$ (Cubic; CAD knowledge Code Capacitor), which is being developed using our methodology. $C^3$ facilitates (i) the automatic generation of a knowledge code for a knowledge-based CAD by processing design documents written in the format near the natural language, such as English or Japanese, and (ii) automatically generation of a design document written in the format near the natural language from the knowledge code. The features of the system facilitate document-based design knowledge management which reduces the designer's load to encode and maintain design knowledge, because it is easier for a designer to treat a natural language description than a coded description.

• Korean Journal of Computational Design and Engineering
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• v.11 no.3
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• pp.164-171
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• 2006

As collaborative design and configuration design are of increasing importance in product development, it becomes essential to exchange the feature and parametric CAD models among participants. A history-based parametric method has been proposed and implemented. But each translator which exchanges the feature and parametric information tends to be heavy because to implement duplicated functions such as the identification of the selected geometries, mapping between features which have different attributes. Furthermore. because the history-based parametric translator uses the procedural model as the neutral format, which is the XML macro file, the history-based parametric translators need a geometric modeling kernel to generate an internal explicit geometric model. To ease the problem, we implemented a shared integration platform, the TransCAD. The TransCAD separates translators from the XML macro files. The translators for various CAD systems need to communicate with only the TransCAD. To support the communication with the TransCAD, we exposed the functions of the TransCAD by using the Automation APIs, which is developed by Microsoft. The Automation APIs of the TransCAD consist of the part modeling functions, the data extraction functions, and the utility functions. Each translator uses these functions to translate a parametric CAD model from the sending CAD system into the XML format, or from the in format into the model of the receiving CAD system This paper introduces what the TransCAD is and how it works for the exchange of the feature and parametric models.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.92-99
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• 2004

With the advent of computers, CAD systems are widely used for various design practice. Complexity of CAD systems and difficulty of exchanging data among different CAD systems, however, do not allow efficient use as desired. In addition, to follow variety of designers' need, CAD activities should be customized. This article proposed a methodology fer developing an intelligent CAD system and the sate-of-the-art technologies described fur customizing CAD systems using API (Application Programming Interface). A basic platform is proposed and a useful application system is implemented to enable a parametric design by directly inputting numerical values on a CAD model. Based on this application, we developed a system that makes it possible to share part family data between SolidEdge and Pro/Engineer. The proposed concept on intelligent CAD systems facilitates integration of external systems such as CAE tools and promotes the use of CAD for both engineering designers and analysts.