• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.346-351
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• 2001

The technique of high speed machining is widely studied in machining field. Because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining is not close behind that of machining tool. So in this study, we made 4 types flat end mill for obtaining data according to tool shape. Especially, we concentrated in helix angle and number of cutting edge. First we confirmed cutting condition by several experiments and measuring cutting force, tool life, tool wear and chip shape according to cutting length. In results, we acquired the fact that 45 degree helix angle and six cutting edge tool is suitable for high speed machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.84-89
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• 1998

BTA drilling among the deep hole drilling is using for the improvement of productivity and the high-efficient working. As the deep hole drilling with BTA drill is satisfied with the required quality by one-pass processing, more deeper hole depth, the accuracy of materials is affected by bending vibration and cutting speed. This paper is studied that the shapes of material (surface roughness, roundness) is affected by cutting condition compared actual roundness with lobe shape with modeling of computer through the experiments in the BTA drilling system with BTA drill.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.10a
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• pp.139-148
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• 1993

A computerized numerical method is presented for the design and/or the investigation of RC members with general shape and material properties subjected to axial load and biaxial bending moment. Slenderness effects can also be considered with the use of the moment magnification factor. The method is based on the summation of stress result- ants on a small area of the cross section which enables the determination of strength interaction diagrams, load contours and moment-curvature relationships for the general section. Thus the presented program HYCOL can be used as a direct tool for design and/or investigation of RC members with general shape subjected to biaxial bending. The accuracy of program HYCOL is established by comparison with experimental results.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.279-287
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• 2003

This paper deals with a comparative study on coupling of Element-free Galerkin(EFG) method and Infinite Element(IE) by IE's shape function. In this study, mapped infinite elements(mapped IE) and decay function infinite elements(decay IE) are coupled with the EFG method. A coupling procedure of EFG-Mapped IE is much easier to be integrated than a coupled EFG-Decay IE. A coupled EFG-IE method used well-defined functions to preserve the continuity and linear consistency on the interface of the EFG region and IE region. Several benchmark problems are solved to verify the effectiveness and accuracy of the coupling algorithms by IE's shape function. The numerical results show that the developed algorithms work well for the elastic problems with infinite boundaries.

• Structural Engineering and Mechanics
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• v.60 no.4
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• pp.667-691
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• 2016

This study focuses on the damage detection of defect types in plate structures based on wavelet transform (WT) and curvelet transform (CT). In particular, for damage detection of structures these transforms have been developed since the last few years. In recent years, the CT approach has been also introduced in an attempt to overcome inherent limitations of traditional multi-scale representations such as wavelets. In this study, the performance of CT is compared with WT in order to demonstrate the capability of WT and CT in detection of defect types in plate structures. To achieve this purpose, the damage detection of defect types through defect shape in rectangular plate is investigated. By using the first mode shape of plate structure and the distribution of the coefficients of the transforms, the damage existence, the defect location and the approximate shape of defect are detected. Moreover, the accuracy and performance generality of the transforms are verified through using experimental modal data of a plate.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.10a
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• pp.12-17
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• 1995

The purpose of this study si the development of a lathe which can cut any pistons of oval shape with high seed, accuracy and precision by CNC (Computer Numerical Control) method. Yaxis which is the position determinating mechanism with high speed response was added to the CNC lathe and the ovality and profile was cut under the control of C-Y-Z axes at same tile. In the case of ovality of $\Phi$ improved up to 2500rpm(Y axis : 83Hz) by high speed cutting than modeling method. Since a personal computer is used, it is easy to change the shape of piston and can be applied promptly to many types of piston shape by only changing data files.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1255-1258
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• 2008

Roll to roll (R2R) system, known as 'web processing', is the process of producing these electronic devices on a roll of flexible plastic. With the need of improved performance and productivity in R2R industry, effective control and on-line supervision for web quality is essential. In this report, we present a system for on-line measurement of wrinkles, one of defects incurring due to compressive stresses developed in the web. This system is able to capture an image generated when a well defined line shape laser beam passes through a transparent web. The system calculates 3D shape information, including the height of the wrinkle on the web, and displays the images for the shape information of the web in real time. By using area scan camera and machine vision laser, this system takes more advantages of setting up as a simple and low cost system compared to the line scan camera systems that widely used in web manufacturing. Specific calibration method and analysis on the achievable accuracy will be discussed.

• International Journal of Contents
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• v.8 no.1
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• pp.30-38
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• 2012

Text extraction and binarization are the important pre-processing steps for text recognition. The performance of text binarization strongly related to the accuracy of recognition stage. In our proposed method, the first stage based on line detection and shape feature analysis applied to locate the position of a business card and detect the shape from the complex environment. In the second stage, several local regions contained the possible text components are separated based on the projection histogram. In each local region, the pixels grouped into several connected components based on the connected component labeling and projection histogram. Then, classify each connect component into text region and reject the non-text region based on the feature information analysis such as size of connected component and stroke width estimation.

• Journal of Korea Multimedia Society
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• v.17 no.12
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• pp.1412-1417
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• 2014

The corpus callosum is the largest part of the brain, which is related to many neurological diseases. Snake model or active contour model is widely used in medical image processing field, especially image segmentation they look into the nearby edge, localizing them accurately. In this paper, corpus callosum segmentation using the snake model, is proposed. We tested a snake model on brain MRI. Then we compared the result with an active shape approach and found that snake model had better segmentation accuracy also faster than active shape approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.217-222
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• 1997

A simple finite element approach to predicting deformed shape and load-deflection curve of elastomers is presented in this paper. The method is based on several simplifications in deformation pattern and material behavior. The conventional updated Lagrangian approach is employed together with material data obtained by a simple tension test. The presented approach is verified through comparison of predicted results with experimental ones and applied successfully to shape design of various elastomers for shock, vibration and noise control. The advantage of the presented approach lies in easiness, simplicity and accuracy enough for engineering application.