• Design & Manufacturing
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• v.6 no.1
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• pp.29-33
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• 2012

A 3D scanner scans and captures the shape of a real-world object. The captured shape can be used to construct three-dimensional model for CAD/CAM applications. In this study we have tried to design a cell phone cover by using the 3D scanner and reverse engineering. A 3D scanner is used to capture the shape of a cell phone. The 3D scanner generates a point cloud as the shape information. A three-dimensional CAD model for the cell phone is constructed from the point cloud. A cell phone cover is designed based on the CAD model of the cell phone. To check the integrity of this design process a prototype of the cover is made and assembled with the cell phone.

• 한국전산유체공학회:학술대회논문집
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• 1995.10a
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• pp.49-54
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• 1995

A numerical analysis on the effect of the front shape on the aerodynamic characteristics of HST model is made, using FVM based general purpose 3D Navier-Stokes eq. solver, TURBO-3D program. Numerical solutions are compared with each case of different front shape for HST model. The result shows a good quantitative aerodynamic characteristic tendencies for variation of front shape of HST. Thus it may be used as a basis in the design of the shape of real HST.

• Journal of the Semiconductor & Display Technology
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• v.11 no.3
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• pp.19-25
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• 2012

The accuracy of Shape From Focus (SFF) technique depends on the quality of the focus measurements which are computed through a focus measure operator. In this paper, we introduce a new approach to estimate 3D shape of an object based on Gaussian process regression. First, initial depth is estimated by applying a conventional focus measure on image sequence and maximizing it in the optical direction. In second step, input feature vectors consisting of eginvalues are computed from 3D neighborhood around the initial depth. Finally, by utilizing these features, a latent function is developed through Gaussian process regression to estimate accurate depth. The proposed approach takes advantages of the multivariate statistical features and covariance function. The proposed method is tested by using image sequences of various objects. Experimental results demonstrate the efficacy of the proposed scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.127-135
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• 2006

The image-based 3D modeling is the technique of generating a 3D graphic model from images acquired using cameras. It is being researched as an alternative technique for the expensive 3D scanner. In this paper, I propose the image-based 3D modeling system using calibrated camera. The proposed algorithm for rendering 3D model is consisted of three steps, camera calibration, 3D shape reconstruction and 3D surface generation step. In the camera calibration step, I estimate the camera matrix for the image aquisition camera. In the 3D shape reconstruction step, I calculate 3D volume data from silhouette using pyramidal volume intersection. In the 3D surface generation step, the reconstructed volume data is converted to 3D mesh surface. As shown the result, I generated relatively accurate 3D model.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.17-18
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• 2015

In manufacturing industry, image scanning technique has made enormous progress in past decades. 3D models have been also very important to continuously monitor the related spatial information for freeform buildings. The process of shape making of 3D scanning is as follows: mesh surface segmentation, NURBS surface generation, and parametric solid model generation. We will review the process and applying process. Especially in the construction industry, 3D data collection by laser scanning has become an high quality 3D models. Therefore, in this research, we have an effort to review construction of reverse design process for freeform envelope using 3D scanning. The technology enables many 3D shape engineering and design parameterization of reverse engineering in the construction site.

• The Journal of Korea Robotics Society
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• v.10 no.1
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• pp.33-41
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• 2015

Recent developments in robotics and intelligent vehicle area, bring interests of people in an autonomous driving ability and advanced driving assistance system. Especially fully automatic parking ability is one of the key issues of intelligent vehicles, and accurate parked vehicles detection is essential for this issue. In previous researches, many types of sensors are used for detecting vehicles, 2D LiDAR is popular since it offers accurate range information without preprocessing. The L shape feature is most popular 2D feature for vehicle detection, however it has an ambiguity on different objects such as building, bushes and this occurs misdetection problem. Therefore we propose the accurate vehicle detection method by using a 3D complete vehicle model in 3D point clouds acquired from front inclined 2D LiDAR. The proposed method is decomposed into two steps: vehicle candidate extraction, vehicle detection. By combination of L shape feature and point clouds segmentation, we extract the objects which are highly related to vehicles and apply 3D model to detect vehicles accurately. The method guarantees high detection performance and gives plentiful information for autonomous parking. To evaluate the method, we use various parking situation in complex urban scene data. Experimental results shows the qualitative and quantitative performance efficiently.

• Korean Journal of Human Ecology
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• v.13 no.6
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• pp.959-966
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• 2004

The purpose of this research is to analyze the shape of gathered skirts made by different gatherings. The shape of gathered skirts is affected by the amount of the gatherings that control fullness along a waistline seam. The gap also has an effect on the shape. We made a few experiments to make gathered skirts in different gathering conditions. The conditions include two types of ratio of gathers, which were given the total amount of gathering, and two types of spread of gathers, which were calculated for waist and hip. Experiments were conducted to figure out the dressed shape through 3-D measurement Exyma- WBS, and also to investigate the proportion, area distribution, and gap of the shape of gathered skirts on the horizontal section map with Rapid Form 2004 SP3, a software for 3-D shape analysis. As the results show, there were differences among the proportion, area distribution, and gap of the dressed shape. It showed that the shape on the horizontal section map was different because the shape between waist and hip per parts on body was not the same.

• Transactions of Materials Processing
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• v.19 no.2
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• pp.132-137
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• 2010

In the multi-pass shape drawing process, the appropriate process design is very important to produce sound products. The reduction ratio, die angle, and the intermediate die shape are very important process variable of the multi-pass shape drawing. The aim of this study is the determination of the reduction ratio, die angle, and the intermediate die shape of the 2 pass shape drawing process for producing steering spline shaft. In this study, FE analysis, Taguchi method, and ANN(artificial neural network) were applied to determine the appropriate reduction ratio, die angle, and intermediate die shape. After the determination of the process variables, FE analysis and drawing experiment were performed to evaluate the effectiveness of the determined process variables. The dimensional accuracy of the final drawn spline shaft was evaluated by using 3D surface profiler and 3D laser digitizing system.

• Journal of Korean Society of societal Security
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• v.2 no.1
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• pp.81-89
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• 2009

A web-based information management system to share engineering data of truss bridge is developed through construction of standardized database of truss bridge. 3D shape information is stored in database according to AP 203 of STEP, and 3D visualization on the web is implemented by using the web 3D technology that helps users to understand geometrical shape of structures, directly. AP209 is used to store structural analysis information such as finite elements, material properties, and analysis result into relational database. Based on the developed database, a prototype of integrated information management system for truss bridge is developed, and it provides additional information such as specifications and inspection information related with shape object to end users.

• Transactions of Materials Processing
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• v.33 no.2
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• pp.123-131
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• 2024

Plastic, the main material of FFF-type 3D printing, exhibits lower strength compared to metal. research aimed at increasing strength is needed for use in various industrial fields. This study analyzed three X-shape infill patterns(grid, lines, zigzag) with similar internal lattice structure. Moreover, tensile test considering weight and printing time was conducted based on the infill line multiplier and infill overlap percentage. The three X-shape infill patterns(grid, lines, zigzag) showed differences in nozzle paths, material usage and printing time. When infill line multiplier increased, there was a proportional increase in tensile strength/weight and tensile strength/printing time. In terms of infill overlap percentage, the grid pattern at 50% and the zigzag and lines patterns at 75% demonstrated the most efficient performance.