• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2142-2153
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• 1995

A digital preview controller using optimal LQ control theory is suggested for tandem cold mills to achieve a remarkable improvement of the thickness accuracy. Optimal preview control system is constructed for each rolling stand of tandem cold mills for which the blocked noninteracting control is carried out, and it is compared with the optimal LQ control system which has only feedback control. And in the cases that all/some of disturbance inputs are previewable, full and partial preview controllers are designed, and their performance effects are compared and discussed. The simulation results show that the performance of tandem cold mills can be improved largely through partial preview control.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.114-122
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• 1995

A digital preview controller is designed for tandem cold mills to achieve a more improvement of the thickness accuracy. Simultaneously a blocked noninteracting controller is synthesized for rejecting the interactive effects among adjacent stands and for controlling independently each roll stand of tandem cold mills. The performance effects and characteristics of the suggested roll contol system are discussed in the practical viewpoint. The simulaltion results show that the thickness accuracy of tandem cold mills can be largely improved by the blocked noninteracting and digital preview controller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.293-298
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• 1995

A digital preview controller is designed for tandem cold mills to achieve a better improvement of the thickness accuracy. And simultaneously a blocked noniteracting controller is synthesized for rejecting the interactive effects among adjacent stands and for controlling independently each roll stand of landem cold mills. The performance effects and characteristics of the suggested roll control system are discussed in the practical view points. The simulation results show that the thickness accuracy of tandem cold mills can be largely improved by the blocked noninteracting and digital preview contoller.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.249-256
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• 2012

ePUB is one of the most pervasive eBook formats since it was announced as a 2009 standard in IDPF(International Digital Publishing Forum). ePUB is compressed as a ZIP Archive format and structured as a standard format of OCF. Domestically and internationally, eBook services applying DRM into ePUB have currently been active, while it does not satisfy various needs from business because it does not support preview service which is due to the encryption of the whole ePUB as a single key. This study suggests a way to apply diverse business models by providing eBook content based on ePUB multiple key encryption method, not by encrypting it simply as a single key. The encryption method which applies a multiple key encryption method is suggested as a practically appliable form together with licence issuing and delivery method and decryption method in eBook readers. The multiple key encryption method suggested in this study will make it possible to support partial preview services of ePUB based eBook content. It will be applied to diverse service models and enhance the security level better then single key based encryption method.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.12
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• pp.17-23
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• 1997

A 3-D vision system is developed to evaluate blanks' line up and monitor gap and thickness difference between blanks in tailored blank welding system. A structured lighting method is used for 3-D vision recognition. Images of sheared portion in blanks are irregular according to roughness of blank surface, shape of sheared geometry and blurring. It is difficult to get accurate and reliable informations in the case of using binary image processing or contour detection techniques in real time for such images. We propoe a new energy integration method robust to blurring and changes of illumination. The method is computationally simple, and uses feature restoration concept, different to another digital image restoration methods which aim image itself restoration and may be used in conventional applications using structured line lighting technique. Experimental results show this system measuring repeatability is .+-. pixel for gap and thickness difference in static and dynamic tests. The data are expected to be useful for preview gap control.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.1
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• pp.11-21
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• 2008

Recently, it has shown an increased interest in 3D stereoscopic contents due to the development of the digital image media. Therefore, many techniques in 3D stereoscopic image generation have being researched and developed. However, it is difficult to generate high immersion and natural 3D stereoscopic contents, because the lack of 3D geometric information imposes restrictions in 2D image. In addition, control of the camera interval and rendering of the both eyes must be repetitively accomplished for the stereo effect being high. Therefore, we propose integrated editing system for 3D stereoscopic contents production using a variety of images. Then we generate 3D model from projective geometric information in single 2D image using image-based modeling method. And we offer real-time interactive 3D stereoscopic preview function for determining high immersion 3D stereo view. And then we generate intuitively 3D stereoscopic contents of high-quality through a stereoscopic LCD monitor and a polarizing filter glasses.