• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.848-853
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• 2005

3D geometric modeling of an object of interest has been intensively investigated in many fields including CAD/CAM and computer graphics. Traditionally, CAD and geometric modeling tools are widely used to create geometric models that have nearly the same shape of 3D real objects or satisfy designers intent. Recently, with the help of the reverse engineering (RE) technology, we can easily acquire 3D point data from the objects and create 3D geometric models that perfectly fit the scanned data more easily and fast. In this paper, we present 3D geometric model generation based on a stereo vision system (SVS) using random pattern projection. A triangular mesh is considered as the resulting geometric model. In order to obtain reasonable results with the SVS-based geometric model generation, we deal with many steps including camera calibration, stereo matching, scanning from multiple views, noise handling, registration, and triangular mesh generation. To acquire reliable stere matching, we project random patterns onto the object. With experiments using various random patterns, we propose several tips helpful for the quality of the results. Some examples are given to show their usefulness.

• Korean Journal of Computational Design and Engineering
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• v.12 no.4
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• pp.283-297
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• 2007

Seamless data integration in the CAx chain of the CAD/CAPP/CAM/CNC has been achieved to a high degree, but research concerning the transfer of data from conceptual sketches to a CAD system should be carried out further. This paper presents a method for reconstructing a 3D model from a freehand sketch. Sketch-based modeling research can be classified into gestural modeling methods and reconstructional modeling methods. This research involves the reconstructional modeling method. Here, Mitani's seminal work, designed for box-shaped 3D model using a predefined template, is improved by leveraging a relational template and specialized for automotive design. Matching between edge graphs of the relational template and the sketch is formulated and solved as the assignment problem using the feature vectors of the edges. Including the stroke preprocessing method required to generate an edge graph from a sketch, necessary procedures and relevant techniques for implementing the template-based modeling method are described. Examples from a working implementation are given.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.2
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• pp.71-78
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• 2001

In ship building industry, CNC and CAM are mostly applied to NC cutting and manufacturing of propeller and prototype ship model. Herein, prototype ship model is producted by CAD/CAM process. Hull form data is obtained from the ship drawing and used for 3D modeling by CAD software Pro/Engineer. CAD data is transferred into CAM s/w SPEEDplus to perform CNC process and the prototype small ship model is manufactured by CNC machine. To solve data transfer among different systems. IGES and STEP neutral formats are currently used. Herein IGES format is adopted for data transfer between CAD/CAM softwares.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.297-300
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• 2008

Since the Three Dimensional Computer Aided Design(3D CAD) appeared in 1990s, Building Information Modeling(BIM) has got the great issue in the construction project nowadays. BIM is the process of managing and generating building information during life cycle of a construction project. And information can be moved to 3D modeling flexibly in BIM. As a result, a field of estimating has also been doing researches in the calculation of the amount of building materials from 3D modeling. And the Construction Cost Estimating Software which is generally used over the world has been trying to be applied to the Construction project in Korea. But, when we consider the productivity, it is less efficient than the existing way in Korea which use the 2D Drawings when they take off the Quantity. Also, there are lots of difference how to estimate the construction cost. between Korea and the others. Because it is a bit hard to apply the software used in the other countries to the construction project in Korea, people couldn't use it well in the construction project actually. In this study, for developing the appropriate construction cost estimating software rooted in 3D in Korea, we suggest 3D CAD Add-on Program for a Quantity Take-off which can move quantitative information to 3D CAD.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.75-81
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• 2004

In this study surface modeling .method with 3D curve net is proposed. For surface modeling, ship hull was divided into several parts, Generated surface was loaded general purpose CAD program through IGES file format, and the quality of generated surface model was checked by CATIA's internal function. Lastly it is tried to find a method for improving the accuracy of surface connection by using the blending method in CATIA and the result was discussed.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.5
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• pp.3-15
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• 2008

This study aims to simulate the 3 dimensional (3D) model of Keum-man connection canal using geographic information system (GIS) as well as considering design in viewpoint of engineering. The canal connects from Keumkang to Mangyungkang in order to supply fresh water into Saemankeum lake. This study used 3 dimensional spatial planning model (3DSPLAM) process to generate the 3D model, which has not only several planning layers in actual process, but also their corresponding layers in modeling process to simulate 3D space of rural villages. The discharge of the canal is $20m^3/s$ on slope of 1/28,400 in the canal length of 14.2km, which consists of pipe line and open channel. This study surveyed the route of the canal and its surrounding environment for facilities to make images in the 3D graphic model. Besides, the present study developed data set in GIS for geogrphical surface modeling as well as parameters in hydraulic analysis for water surface profile on the canal using HEC-RAS model. From the data set constructed, this study performed analysis of water surface profile with HEC-RAS, generation of digital elevation model (DEM) and 3D objects, design of the canal section and route on DEM in AutoCAD, and 3D canal model and its surrounding 3D space in 3DMAX with virtual reality. The study result showed that the process making 3D canal model tried in this study is very useful to generate computer graphic model with the designed canal on the surface of DEM. The generated 3D canal can be used to assist decision support for the canal policy.

• Journal of Information Technology Applications and Management
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• v.29 no.6
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• pp.135-144
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• 2022

In this study, we transformed 4680 type lithium-ion batteries to 3-dimensional CAD models and present a methodology to detect defects using Radon inverse transformation. Transparency was applied to the model to make it look like a CT image when viewed from the front. One normal and three defect models were created and analyzed. The models were saved as image files while rotating at a certain angle. Then, we used the Radon inverse transformation to reconstruct the original 3D geometry from the image files. Finally, we successfully found defects in the defect models for three cases.

• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.255-264
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• 2008

Research that reconstructs a 3D model from a freehand 2D sketch has gained attention since 1990s, when data integration in the CAD/CAPP/CAM/CNC chain was an important issue. However, 2D sketches in the conceptual design phase have not been integrated with the downstream CAD/CAPP/CAM/CNC chain. In this paper, we present a method to interface a freehand sketch modeling to commercial CAD systems by mapping a sketch modeling history to the macro parametric history. We use an extended ISO10303-112 standard to represent the modeling history in a gestural modeling system and translate sketch files to neutral macro files. Macro parametric translators are used to translate netural macro files to commercial CAD files.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.259-261
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• 2016

Cable is very essential material for ship operation as connecting element for whole electrical facilities of ship. The material cost and installation man-hour increment caused by re-installation is unavoidable if cable route has some problem. The purpose of this study is to suggest methods to implement the cable visualization functionality for verifying whether cable route is accurate or not in design phase. This functionality is conducted by representing color of 3D model for strong visibility by refer to textual cable routing information. The electrical engineer can provide cable route information more accurate and on time for cable installation department. As a result, the material cost and installation man-hour reduce due to decreasing ratio of re-installation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5243-5250
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• 2013

BIM(Building Information Modeling) enables 3D model-base management for all information produced by construction project during its life cycle. Also as a national policy, BIM has been institutionalized as design criteria. But, on the matter of 2D drawing using BIM software (Revit Architecture), it has been recognized as difficult to realize the same quality drawing drawn by CAD. The purpose of this study is verifying the possibility of printable design drawing implemented by BIM software at the same quality of 2D shop drawing drawn by 2D CAD. Through the analysis of basic design elements of 3D BIM software and 2D CAD software, with the case of partial cross sectional drawing which is most faithful representation of the basic design elements, this study find out that the 3D BIM software can produce the same quality 2D printable drawing utilizing its implicit function.