• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.808-811
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• 2000

The product of stereolithography is consist of gathering the single strand. Therefore the accuracy of the shape is related to the linear shrinkage of the single strand. The resin temperature change affect on curing properties. This article will propose the interaction between material temperature and shape accuracy by resin temperature control. The main concern of this article is related to the improvement of end product's shape accuracy by the persuit for the filles curing criterion.

• Transactions of Materials Processing
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• v.18 no.4
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• pp.283-289
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• 2009

The multi-stage shape drawing is used to obtain long shaped products with high levels of dimensional accuracy and quality. It is important to design the cross sectional shapes of the intermediate passes to meet the required dimensional accuracy of the final product in the multi-stage shape drawing. Until now, the cross sectional shapes of the intermediate passes have been designed by the experiences. It is still remained unsolved problem to design the cross sectional shapes of intermediate pass drawing dies in the multi-pass shape drawing. In this study, a new technique is proposed to design the cross sectional shapes of intermediate passes. The proposed method is applied to a multi-stage shape drawing for a LM-guide which is one of the representative shape drawing products. In order to verify the effectiveness of the proposed method, FE-simulation and experiments have been carried out. The dimensional accuracy of the proposed method is compared with that of the conventional shape drawing process designed by the industrial engineers.

• Journal of Biosystems Engineering
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• v.26 no.3
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• pp.279-286
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• 2001

The purpose of this study were to organize a sorting system, to develop an algorithm of image processing for the shape sorting, and to finally develop a scientific and objective shape sorting system of Korean Red-Ginseng for mechanization of the shape sorting. The results of this study are followed. 1. The shape sorting system of Korean Red-Ginseng consists of a control computer, a color CCD camera(WV-CP4110) for image processing, an image processing board(DT3153), and an image acquisition unit. 2. Many image processing skill, such as sliding, stretching, threshold, binary and D$\sub$t/ were used to analyze the shape sorting factors of Korean Red-ginseng. 3. The sorting accuracy of the shape sorting system for the Korean Red-Ginseng was 74.7%. It is 21.1% lower than that of human inspector. Although the system has low accuracy, using more cameras may improve its sorting accuracy.

• Korean Journal of Computational Design and Engineering
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• v.8 no.4
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• pp.212-221
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• 2003

In order to reduce the lead-time and cost, the technology of rapid prototyping (RP) has been widely used. A new rapid prototyping process, transfer-type variable lamination manufacturing process by using expandable polystyrene foam (VLM-ST), has been developed to reduce building time, apparatus cost and additional post-processing. At the same time, VLM Slicer, the CAD/CAM software for VLM-ST has been developed. In this study, algorithms for accuracy improvement of VLM-ST, which include offset and overrun of a cutting path and generation of a reference shape are developed. Offset algorithm improves cutting accuracy, overrun algorithm enables the VLM-ST process to make a shape of sharp edge and reference shape generation algorithm adds additional shape which makes off-line lamination easier. In addition, proposed algorithms are applied to practical CAD models for verification.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.112-118
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• 2008

In order to meet the optical performance in the process of the micro lens manufacturing with plastics, it is important to embody accuracy in shape and surface roughness to the intended design. Since it is difficult to machine exactly the mold core of lens fit to the designed shape, in this paper, a simple program using MATLAB is developed for shape correction of the mold core after first machining it. This program evaluates correction parameters(aspheric coefficients and curvature) and generates aspheric NC data for compensating the core surface in prior machining process. The program provides the way to manufacture plastic injection molding lens with aspheric shape of high precision, and is expected to be effective for correction and to shorten the processing time.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.129-135
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• 1997

Experimental studies have been carried out to obtain uniform cups by one operation of backward extrusion. A lot of factors on dimensional accuracy of backward extruded cups are billet material, billet shape, punch shape, punch velocity, geometry of tool, tool material, and lubrication etc. In manufacturing cup-shaped parts by backward extrusion, it is very important to design the initial billet shape or the preform. The objective of this paper is to find that the shape of the initial billet is related to dimensional accuracy and also to manufacture the more accurate product simultaneously reducing the loss of material as forming the shape of the initial billet by means of upsetting.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.43-50
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• 2012

Database for the information of the shape accuracy is constructed with the finite element stamping analysis of the center pillar member. Analyses are carried out in order to investigate the effect of tool compensation on the product quality previously performed by an expert in the press shop. The compensation procedure is provided with three sequences for improving shape accuracy of the member by reducing the amount of springback. The analysis result shows that shape inaccuracy in the product is caused by sagging and twisting phenomena from displacement of the section part due to excessive amount of springback. From the database with springback analyses, design modification guidelines are proposed for improving the shape accuracy. The guideline is directly applied to a member with the similar shape and the sound product is obtained successfully reducing the amount of springback.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.1955-1960
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• 2010

A performance of CNC 3-axis pipe profile-cutting machine we developed was evaluated by measuring and verifying a positioning accuracy of its feeding unit and a cutting shape accuracy of pipe workpiece. The positioning accuracy was verified by comparing moving distance actuated by PLC motion controller with actual one measured by a laser interferometer. The cutting shape accuracy was also verified by comparing a cutting shape obtained through scanning and 3D modeling the pipe workpiece with that through CL data.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.123-127
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• 1999

This paper suggests the establishment of high-accuracy and high-efficiency machining method of scroll shape workpiece by using the feed control method. The cutting paths for machining the inside and outside surfaces of the scroll-shape workpiece are calculated, and the calculation method of the cutting chip areas based on the coordinate of the base circle is shown. A feed control method is proposed for a constant cutting area and cutting force. By machining test of scroll shape workpiece, The machined accuracy of wrap, tool wear, and surface roughness are evaluated. By this method, Reduction of the machining time and large increase of the efficiency can be expected.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.337-340
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• 2008

The cross section shape of intermediate die is one of important parameters to obtain dimensional accuracy of final product in shaped drawing process. Until now it has been designed by the experience or trial and error of the expert. In this study, the cross section shape of intermediate die fur spline shape is determined by the electronic field analysis, shape factor method. The result of the electronic field analysis, shape factor method has been compared with that of the present method. The effects of cross section shape on the dimensional accuracy were investigated by using FE analysis. And then the multi-stage shaped drawing experiments were performed to verify the results of FE analysis. As a result, the cross section shape from the electronic field analysis had the good dimensional accuracy. The electronic field analysis can be used for the method to obtain the cross section shape of intermediate die in shaped drawing process.