• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 1999.07a
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• pp.156-164
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• 1999

This paper shows that the configuration of power transmission lines currently in place is suitable on the basis of calculated magnetic field strengths. The magnetic fields were computed for typical current distributions on power transmission lines for electric railways, which are characterized by severe load fluctuations and phase distortions. The result of the numerical analysis are compared with th ELF guidelines of magnetic fields from several case studies. The final conclusion reached in that effects of the magnetic fields near power transmission lines for electric railways are not significant enough to cause a biological safety concern.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.35-38
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• 1996

A new high power factor converter using transformer magnetizing energy for power factor correction with a single-switch/single-stage is proposed. The proposed converter gives the good power factor correction, low current harmonic distortions, and tight output voltage regulation. The prototype shows the IEC555-2 requirements are met satisfactorily with nearly unity power factor.

• Journal of Information Processing Systems
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• v.2 no.3 s.4
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• pp.143-146
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• 2006

We have designed an embedded controller for the control of a diesel generator using an embedded system. The generator is monitored and controlled remotely via the internet in real-time. The proposed digital controller is designed to handle precisely the distortions and noises of the signals emanating from the diesel generator, and enables abnormal operation of the diesel generator to be notified to the remote manager using the Short Message Service (SMS) of the Internet, which enables the appropriate personnel to take action by remote control according to the incoming messages.

• International Journal of Contents
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• v.5 no.2
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• pp.32-37
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• 2009

A new video watermarking scheme with robustness against collusion and synchronization attacks is presented. We propose to embed only a few copies of the watermark along the temporal axis into frames, which are located at the borders of each two different plotlines of the video. As a result, each change of the video plotline is transformed into pulse, which is used for watermark embedding and extraction. In addition, since we embed a watermark only into a small number of frames, the distortions of the video are reduced to minimum. Experimental results show the robustness of the proposed scheme.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1749-1752
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• 2007

The Near to Eye Display (NED) solves the problem of having a display larger than a small portable device. The virtual image of the NED is created using a microdisplay and imaging optics. It is important that the optics does not interfere with the human visual system and that the device is light, compact and easy to wear. In this paper the principles of a biocular NED, which is based on a novel diffractive Exit Pupil Expander (EPE), are presented. The optical system is compact and intrinsically free from distortions and misalignments.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.38-39
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• 2003

In this Paper, Laser nonlinearity is analyzed by Rate Equation. Two-tone third-order intermodulation distortions are calculated from Rate Equation. Simulation results and experiment results are compared.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.463-467
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• 2003

Optical architecture and experimental results on low cost multiview autostereoscopic projection display are presented. The display, containing only one high resolution projection panel and only one projection lens is capable of displaying multiview autostereoscopic images. Key components, applied in the display are segmented mirror for splitting the projection beam and one-dimensional diffuser with slanted axis of diffusion for viewing zone formation. Image distortions, inherent in the display have been compensated with opposite sign pre-distortion of projected perspective images.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.7
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• pp.332-334
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• 2006

In this paper, we present an equalization scheme for 8-VSB signals for the ATSC DTV system. We propose a complex feedback filter and complex feedback sample generator for DFE to equalize 8-VSB signals in order to efficiently remove multipath distortions causing leakages from the qudrature component. We show that the proposed structure outperforms the conventional DFE used for the digital VSB which uses a real-valued feedback filter with real-valued decisions.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1205-1206
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• 2008

In the conventional floating display system some image distortions might be occurred in the floating image plane, in which a flat screen has been mostly used for providing an adequate input image plane. In this paper, as a new approach to alleviate image distortion problem in a floating display system, a curved screen is suggested by through some computer simulation using an optics design program of Light Tools.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.387-388
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• 1996

The principles to attain improved accuracy in a new controller for large CCD and mosaics detectors with the application of 16- and 32-bit DSP are presented.