• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.3
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• pp.113-120
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• 2003

Plasma display panels normally utilize the binary coded light emission scheme for gray scale expression. Subsequently, this expression method makes dynamic false contours. We propose the "E3DSM(enhanced 3-dimension scattering method)" that improved existing 3-d scattering method and the "HAM(histogram analysis method)" that is decided the driving schemes and subfield selections with histograms of images. Simulation results show the improving image quality.

• Information Display
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• v.20 no.3
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• pp.3-9
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• 2019

본 논문에서는 HDR imaging 기술의 기본 원리와 전반적인 내용에 대해서 살펴보았다. 특히 최근 많은 관심을 받고 있는 딥러닝 기술에 대한 소개와 HDR imaging 기술에 어떤 형태로 적용되고 있는지에 대한 내용 및 최근 동향에 대해서도 함께 살펴보았다. HDR imaging 기술은 기존 디스플레이 대비 높은 인지 화질을 제공해주기 때문에 현재 많은 관심을 받고 있는 기술이며, 디스플레이 패널 기술 발전과 함께 지속적으로 연구되어야 하는 기술이다. 이와 관련해서 현재 많은 연구 기관 등에 대해서 관련 기술에 대해서 연구하고 있지만, 아직 많은 부분에 있어서 해결되어야 하겠다. 특히 궁극적으로 인간의 시각 특성을 고려한 영상 출력을 위해서는 디스플레이 기술 발전과 함께 알고리즘 측면에서 많은 연구가필요하겠다. 따라서 이러한 HDR imaging 기술을 포함한 다양한 알고리즘 개발을 통해서 현재보다 높은 수준의 실감형 디스플레이 기술 개발이 이루어질 것으로 기대된다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.5
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• pp.504-512
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• 2002

This paper presents a new subfield method that can alleviate the visual artifact called the dynamic false contour (DFC), which occurs on plasma display panels. Nothing that the DFC is caused by the difference of time intervals between the adjacent subfields, we propose a constant slope code, in which the differences are maintained to be constant. Also, we propose a subfield code that can minimize the mean absolute error, considering the trade-off between the peak magnitude of the error and its duration. We will show that the proposed subfield method maintains an adequate performance in the view point of the human visual system, since the bound of the errors increases with the gray scale.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.53-58
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• 2018

The modern industry requires the precision machining as well as the high productivity. The machine tool structure should be evaluated in aspects such as durability, static stability, precision rate and the dynamic stability which is one of the most critical characteristics in determining the magnitude of vibrations. In this study, the dynamic properties of a pipe cutting machine were investigated to analyze the structural vibrations of the machine, and further to improve the structural stability and precision machining. Frequency response test and computer simulation have been utilized for the analysis and the design alterations. And the result shows that proposed design alterations can reduce the vibrations of the machine substantially.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.38-43
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• 2019

In this study, a hydraulic press structure has been investigated in order to enhance the precision machining and the productivity, which are generally damaged by the structural deformation from the pressure and the vibrations originated from the centrifugal forces from the rotating parts of the machine. Computer simulation based on the finite element method has been utilized for the analysis of static and dynamic characteristics to investigate each component's critical points, and to further improve the static and dynamic stabilities of a hydraulic press structure. The result shows that the deformations and the vibrations of the machine could be reduced 35% without increasing the weight of the machine.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.178-183
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• 2021

This paper describes a dynamic spectroscopic ellipsometry based on dual-wavelength calibration. DSE provides ellipsometric parameters at rates above 20 Hz, but the interferometer's sensitivity to temperature makes it difficult for that proposed system to maintain stable 𝜟k over long periods of time. To solve this problem, we set up an additional path in the DSE to perform simulations of the polarization phase calibration method using dual wavelengths. Through simulation, we were able to eliminate most of the polarization phase error and maintain a stable 𝜟k in the long-term stability experiment for 10 hours. This is the result that the 𝜟k stability of the proposed system is improved tens of times compared to the existing system.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.90-95
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• 2023

We describe an optimal alignment method for improving accuracy of dynamic spectroscopic polarimeter based on monolithic polarizing interferometer. The dynamic spectroscopic polarimeter enables real-time measurements of spectral ellipsometric parameters by using a spectral carrier frequency concept. However, the non-polarizing beam splitter used in the monolithic polarizing interferometer cannot maintain the polarization state perfectly due to phase retardation caused by optical anisotropic characteristics of the non-polarizing beam splitter, resulting in degraded measurement accuracy. The effect of the beam splitter can be minimized through optimal alignment of the polarizers used in the polarizing interferometer and the analyzer. We demonstrate how much the proposed alignment method can enhance the measurement accuracy by comparing with previous alignment approach.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.920-928
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• 2016

Recently high dynamic range imaging technique is hot issue in computer graphic area. We present a progressive tone mapping algorithm, which is based on weighted least squares optimization framework. Our approach combines weighted least squares filtering with iCAM06 model. To show more perceptual high dynamic range images in conventional display, we decompose high dynamic range image into base layers and detail layers. The base layers are obtained by using weighted least squares filter. Then, we adopt chromatic adaption function and non-linear compression function to deal with base layers. Only the base layers reduce contrast, and preserving detail. The image quality assessment shows that our tone mapped image is more similar to original high dynamic range image. Moreover, the subjective result shows our algorithm produces more reliable and pleasing image.

• Journal of IKEEE
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• v.22 no.4
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• pp.901-906
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• 2018

Due to the development of display technologies for images, the resolution and quality of images are increasing day by day. In accordance with the development of the display technology, researches have been actively conducted on technologies for converting and displaying existing images to higher resolution and quality. Since the results of theses studies are included in the image signal processor, hardware implementation is indispensable. In this paper, we propose a real-time HDR(High Dynamic Range) conversion hardware implementation of LDR(Low Dynamic Range) image using luminance distribution. The proposed method extracts the features of the image using the histogram of the luminance distribution, and extends the luminance and color based on the extracted features. In addition, when the proposed method is designed by hardware IP(Intellectual Property) and its performance is verified, 4K DCI(Digital Cinema Image) can be handled at a rate of 30fps at 265.46MHz.

• Journal of the Korea Society of Computer and Information
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• v.21 no.11
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• pp.23-30
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• 2016

In this paper, we propose an adaptive histogram projection technique for dynamic range compression and an efficient detail enhancement method which is enhancing strong edge while reducing noise. First, The high dynamic range image is divided into low-pass component and high-pass component by applying 'guided image filtering'. After applying 'guided filter' to high dynamic range image, second, the low-pass component of the image is compressed into 8-bit with the adaptive histogram projection technique which is using global standard deviation value of whole image. Third, the high-pass component of the image adaptively reduces noise and intensifies the strong edges using standard deviation value in local path of the guided filter. Lastly, the monitor display image is summed up with the compressed low-pass component and the edge-intensified high-pass component. At the end of this paper, the experimental result show that the suggested technique can be applied properly to the IR images of various scenes.