• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1326-1331
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• 2005

A product is designed through the collaboration among engineers in several fields such as design, analysis, and manufacturing. These series of functions are performed repeatedly during the design process. An easy access and exchange of the model data is one of the important elements that help to shorten production development time. Especially, the importance of data exchange between CAD and CAE applications is increasing in the field of verification and estimation of the products. However, information and knowledge of model which is generated by a CAD software cannot be transferred by a function of CAE software, as an exchange of product data between CAD and CAE applications. It causes a delay in design analysis and eventually discourages a designer's effort in improving his design. Therefore, we need to integrate a commercial CAD and CAE applications effectively and to use the same interface on a product model obtained in a distributed environment. This paper shows how to implement a model exchange between CAD and CAE by a web-service and how to provide a communication environment among engineers.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.95-102
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• 2006

A product is designed through the collaboration among engineers in several fields such as design, analysis, and manufacturing. These series of functions are performed repeatedly during the design process. An easy access and exchange of the model data is one of the important elements that help to shorten production development time. Especially, the importance of data exchange between CAD and CAE applications is increasing in the field of verification and estimation of the products. However, information and knowledge of model which is generated by a CAD software cannot be transferred by a function of CAE software, as an exchange of product data between CAD and CAE applications. It causes a delay in design analysis and eventually discourages a designer's effort in improving his design. Therefore, we need to integrate a commercial CAD and CAE applications effectively and to use the same interface on a product model obtained in a distributed environment. This paper shows how to implement a model exchange between CAD and CAE by a web-service and how to provide a communication environment among engineers.

• Korean Journal of Computational Design and Engineering
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• v.11 no.2
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• pp.128-137
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• 2006

In this paper, a CAD/CAE integrated optimal design system is developed, in which design and analysis process is automated using CAD/CAE softwares for a complex model in which the modeling by parametric feature is not easy to apply. Unigraphics is used for CAD modeling, in which the process is automated by using UG/Knowledge Fusion for modeling itself and UG/Open API function for the other functions respectively. Structural analyses are also carried out automatically by ANSYS using the imported parasolid model. The developed system is applied for the PLS(Plasma Lighting System) consisting of more than 20 components, which is a next generation illumination system that is used to illuminate stadium or outdoor advertizing panel. The analyses include responses by static, wind and impact loads. As a result of analyses, tilt assembly, which is a link between upper and lower body, is found to be the most critical component bearing higher stresses. Experiment is conducted using MTS to validate the analysis result. Optimization is carried out using the software Visual DOC for the tilt assembly to minimize material volume while maintaining allowable stress level. As a result of optimization, the maximum stress is reduced by 57% from the existing design, though the material volume has increased by 21%.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.523-528
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• 2001

There are many difficult problems in analyzing the flow characteristics in a high voltage circuit breaker such as shock wave and complex geometries, which may be either static or in relative motion. Although a variety of mesh generation techniques are now available, the generation of meshes around complicated, multicomponent geometries like a gas circuit breaker is still a tedious and difficult task for the computational fluid dynamics. This paper presents the computational method for analyzing the compressible flow fields in a high voltage gas circuit breaker using the Cartesian cut-cell method based on the CFD-CAD integration, which can achieve the accurate representation of the geometry designed by a CAD tools. The technique is frequently satisfied, and it will be almost universally so in the future, as the CFD-CAD traffic increases.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.183-192
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• 2006

A CAD/CAM system has been developed for rapid prototyping (RP) of microfluidic devices based on excimer laser micromachining. The system comprises of two complementary softwares. One, the CAM tool, creates part programs from CAD models. The other, the Simulator Tool, uses a part program to generate the laser tool path and the 2D and 3D graphical representation of the machined microstructure. The CAM tool's algorithms use the 3D geometry of a microstructure, defined as an STL file exported from a CAD system, and process parameters (laser fluence, pulse repetition frequency, number of shots per area, wall angle), to automatically generate Numerical Control (NC) part programs for the machine controller. The performance of the system has been verified and demonstrated by machining a particle transportation device. The CAM tool simplifies part programming and replaces the tedious trial-and-error approach to creating programs. The simulator tool accepts manual or computer generated part programs, and displays the tool path and the machined structure. This enables error checking and editing of the program before machining, and development of programs for complex microstructures. Combined, the tools provide a user-friendly CAD/CAM system environment for rapid prototyping of microfluidic devices.

• 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.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.137-142
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• 1999

The purpose of this study is to develope a CAD-based tool for rasterization of polygonal vector map in AutoCAD. To identity the layer property of polygonal entity with user-defined coordinates as topology, algorithm in processing entity data of selection set that intersected with scan line was used, and the layers were extracted sequentially by sorted intersecting points in data-list. In addition to the functions for querying and modifying topology, two options for mapping were set up to construct plan projection type and to change meshes' properties in existing DTM data. In case of plan projection type, user-defined cell size of 3DFACE mesh is available for more detailed edge, and topological draping on landform can be executed in case of referring DTM data as an AutoCAD's drawing. The concept of algorithm was simple and clear, but some unexpectable errors were found in detecting intersected coordinates that were AutoCAD's error, not the utility's. Also, the routines to check these errors were included in algorithmic processing. Developed utility named MESHMAP was written in entity data control functions of AutoLISP language and dialog control language(DCL) for the purpose of user-oriented interactive usage. MESHMAP was proved to be more effective in data handling and time comparing with GRIDMAP module in LANDCADD which has similar function.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.2
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• pp.89-100
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• 1993

This paper is a study on the earth volume calculation using CAD and LISP(LIST Processing) in the route alignment. The utility enlargement in the industry field and the considerable progress of computer make the automatic design and manufacture for the development of CAD/CAM/CAE technique possible, and the automatic design of civil engineering works is continuously progressive. In this study we are intend to improve an effect of civil engineering work by the automatic earth volume calculation in route alignment. This paper aims to construct the automatic design system of civil engineering work and the procedures; (1) The programming of the self-scanning program of the land information introducing Digital Terrain Model concept in the map (2) Systematic algorithm construction using LISP and grafting CAD system (3) Automatic design and calculation of the mass curve and earth volume.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1596-1606
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• 2006

There has been more increased the development of 3D technique since many 3D contents of 3D graphic model, 3D mobile/computer game, and 3D CAD have been serviced in Web or industry fields. Therefore, the watermarking system is more required to protect the copyright for 3D contents. Currently there has been researched about the watermarking for 3D graphic model of mesh or NURBS. However, watermarking technique based on CAD design drawing leaves something to be desired yet. This paper proposed the watermarking technique for 3D CAD design drawing using Line and Arc components. After drawing out Line and Arc components from designed drawing, we embed the watermark into both the length of Line component and the radius of Arc component. Experimental results verified that the proposed algorithm satisfies the transparency about watermarked drawing and also has the robustness against several attacks by using public CAD tool.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.2
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• pp.369-383
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• 2020

This study proposes a method to effectively teaching technic for pattern development and virtual garment manufacturing by adopting the K-MOOC platform for the Apparel Pattern CAD curriculum. According to K-MOOC guidelines, Apparel Pattern CAD curriculum were developed and presented through the K-MOOC platform. A questionnaire survey was utilized to evaluate K-MOOC platform features in terms of learner satisfaction when adopting the 5-point Likert scale. Questionnaire survey participants included 52 college students. The result of the survey found that most of the attributes of the K-MOOC platform were highly rated in terms of interaction and learning effectiveness. The user interface of the K-MOOC platform were shown to be satisfactory in terms of usability. Participants gave a positive assessment of the benefits of online lectures when comparing online and offline lectures. In particular, the preference for online lectures in computer-related courses such as CAD was higher than the offline. It was concluded that the Apparel Pattern CAD curriculum based on the K-MOOC platform was effective and satisfactory for learners in various aspects.