• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.47-54
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• 2009

Spin coaters are the essential instruments in micro-fabrication processes, which apply uniform thin films to flat substrates. In this research, a spin coater diagnosis system is developed to detect the abnormal operation of TFT-LCD process in real time. To facilitate the real-time data acquisition and analysis, the circular-buffered continuous data transfer and the short-time Fourier transform are applied to the fault diagnosis system. To determine whether the system condition is normal or not, a steady-state detection algorithm and a frequency spectrum comparison algorithm using confidence interval are newly devised. Since abnormal condition of a spin coater is rarely encountered, algorithm is tested on a CD-ROM drive and the developed program is verified by a function generator. Actual threshold values for the fault detection are tuned in a spin coater in process.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2769-2771
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• 2003

New high technology has been developing rapidly in telecommunication. That wanted to need a display which economical and useful color STN is satisfactory advantages for this condition, and it can control easy better than TFT, organic electroluminescence. But color STN has restriction on real time. Thus, in this paper, we want to control color STN with frequency transform method on converter.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1886-1887
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• 2007

New high technology has been developing rapidly in telecommunication. That wanted to need a display which economical and useful color STN is satisfactory advantages for this condition, and it can control easy better than TFT, organic electroluminescence. But color STN has restriction on real time. Thus, in this paper, we want to control color STN with frequency transform method on converter.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.566-573
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• 2013

Inverse synthetic aperture radar(ISAR) images have been widely used in non-cooperative target recognition(NCTR). One of the most important issues in ISAR imaging is the improvement of the image smeared by target motion. In this paper, we propose the discrete Gabor representation(DGR) in an oversampling scheme for efficient acquisition of high-quality ISAR images. The DGR compartmentally assigns the Gabor coefficients to unit cells of the time-frequency grid related to the given Gabor logons. Thus, it can show an excellent time-frequency concentration and effectively discriminates the Doppler components from point-scatterers. The simulation results demonstrated that the DGR not only obtained high-quality ISAR images but also retained computational efficiency.