• 대한전자공학회논문지
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• 제25권1호
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• pp.72-80
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• 1988

In this paper, new adaptive interframe filtering methods have been proposed to separate the luminance and chrominance components in NTSC composite signals. In thess methods, the composite signals are adaptivelty processed in three dimensions according to the local change or movement of the picture. For interframe processing, two algorithms have been proposed which adapt three filters in the horizontal, vertical and temporal directions to the magnitude f detection signal dependent upon both the movement and local change of the picture. The three kind of filters have been used at the sampling rate of four times the subcarrier frequency. The various quantitative measures have been introduced to compare the objective performance of the conventional methods and that of proposed ones by computer simulation.

• 전기학회논문지
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• 제61권11호
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• pp.1650-1655
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• 2012

AC-PDPs have recently achieved good performance and their image quality can sufficiently compete with the LCD TV. However, it is necessary more effort to improve the luminance and luminous efficacy in the PDP technology. The gas mixture ratio plays a very important role in discharge characteristics, but the mechanism of gas discharge is complex and complicated. In this paper, we investigate the mechanism of gas discharge with Ne+Xe miture ratio through zero and two dimensional fluid simulation.

• Journal of Information Display
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• 제8권4호
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• pp.10-14
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• 2007

LCD performance is generally evaluated in terms of luminance and color versus viewing angle. In the present paper, we show that this type of display can be favorably characterized in terms of polarization. We show that ELDIM EZContrast instrument which is routinely used for viewing angle measurements can be upgrade for measuring the polarization state of the light at each incidence and azimuth angle. More precisely, the degree of polarization of light, its ellipticity and polarization direction can be measured at each incidence angle between 0 and $88^{\circ}$ and for all the azimuth angles (from 0 to $360^{\circ}$). Important differences between the displays can be detected and related to their internal structures when luminance and color profiles are quite similar. The same setup can also be used to characterize optical components of the LCDs.

• 대한의용생체공학회:의공학회지
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• 제14권1호
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• pp.63-72
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• 1993

In this paper, the effect of background grey levels on the visual perception of target image displayed on CRT monitor has been investigated. The purpose of this study is to investigate the efficacy of CRT monitor as a display medium of image Information especially in medical imaging field. Tllree sets of experiments have been performed in this study : the first was to measure the luminance response of CRT monitor and to find the best fitting equation, and the second was the psychophysical experiment measuring the threshold grey level differences between the target image and the background required for visual discrimination (or various background grey levels, and the third was to develop a visual model that is predictable of the threshold grey level difference measured in the psychophysical experiment. The result of psycophysical experiment shows that the visual perception performance is significantly degraded in the range of grey levels lower than 50, which is turned out due to she low luminance change of CRT monitor in this range while human eye has been adapted lo relatively bright ambient illumination. And it Is also shown in the simulation study using the developed visual model that the dominant factor degrading the visual performance is the reflected light from the monitor surface by ambient light in general illumination condition.

• 한국멀티미디어학회논문지
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• 제19권1호
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• pp.10-21
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• 2016

Images taken from outdoor are degraded quality by fog or haze, etc. In this paper, we propose a method that provides the visibility improved images through fog or haze removal. We proposed haze removal method that uses brightness transform based on atmospheric scatter coefficient rate with local histogram equalization. To calculate the transmission rate that indicate fog rate in original image, we use atmospheric scatter coefficient rate based on quadratic equations about haze model. And primary brightness transformed image can be obtained by using the obtained transmission rate. Also we use local histogram equalization with proposed brightness transform for effectively image visibility enhancement. Unlike existing methods, our method can process real-time with stable and effect image visibility enhancement. Proposed method use only the luminance images processed by good performance surveillance systems because it represents the real-time processing is required, black-box, digital camera and multimedia equipment is applicable. Also because it shows good performance only with the luminance images processed, Surveillance systems, black boxes, digital cameras, and multimedia devices etc, that require real-time processing can be applied.

• Journal of Information Display
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• 제7권2호
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• pp.26-30
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• 2006

Insertion of a thin lithium fluoride (TLF) layer between an emitting layer (EML) and an electron transporting layer has resumed in the developement of a highly efficient and bright organic light-emitting diode (OLED). Comparing with the performance of the device as a function of position with the TLF layer in tris-(8-hydroxyquinoline) aluminum $(Alq_{3})$, we propose the optimal position for the TLF layer in the stacked structure. The fabricated OLED shows a luminance efficiency of more than 20 cd/A, a power efficiency of 12 Im/W (at 20 mA/$cm^{2}$), and a luminance of more than 22 000 cd/$m^{2}$ (at 100 mA/$cm^{2}$), respectively. We suggest that the enhanced performance of the OLED is probably attributed to the improvement of carrier balance to achieve a high level of recombination efficiency in an EML.

• 한국통신학회논문지
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• 제25권3B호
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• pp.541-548
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• 2000

In the MPEG-4 standardization phase, many methods for coding the irregular shaped VOP (video object Plane) have been researched. Texture coding is one of interesting research items in the MPEG-4. There are the Low pass extrapolation (LPE) padding, the shape adaptive DCT (SA-DCT), and the Extension-Interpolation (EI)/2D-DCT proposed in [1] as texture coding methods. the EI/2D-DCT is the method extending and interpolating luminance values from and Arbitrarily Shaped (AS) image segment into an 8 x 8 block and transforming the extended and interpolated luminance values by the 8x8 DCT. although the EI/2D-DCT and the SA-DCT work well in coding the As image segments. they are degraded since they use one-dimensional (1-D) methods such as the 1D-EI and the 1D-DCT in the two-dimensional (2-D) space. in this paper, we analyze the performance of the EI/2D-DCTand propose a new non-symmetric sig-sag scanning method, which non-symmetrically scans the quantized coefficients in the DCT domain to improve the EI/2D-DCT.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1412-1413
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• 2006

In this research, an organic thin 13 passivation layer was newly adopted to prefect the organic layer from ambient moisture and oxygen. As the organic thin film passivation layer, poly methyl methacrylate thin films (ppMMA) were deposited using a plasma polymerization technique. In order to their passivation performance for OLEDs, water vapor transmission rate (WVTR) of the ppMMAs were analyzed and luminance-current-voltage (L-I-V)/luminance-time (L-T) characteristics of the OLEDs with and without ppMMA passivation layer were investigated. The OLEDs had a structure of ITO/TPD (HTL)/Alq3(EML&ETL)/Al. The OLED with ppMMA passivation layer showed improved L-T performance than that of without ppMMA passivation layer.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.397-400
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• 2010

동영상은 촬영 당시의 주변의 조명변화에 의해 원치 않는 밝기 변화가 발생한다. 이러한 훼손을 플리커라 하고 시각적으로 불안정한 영상의 흔들림으로 인지된다. 플리커는 동영상 시퀸스로부터 유용한 정보를 추출하기 힘들게 하므로 미리 제거하여 안정된 형태로 만들어야 한다. 본 논문은 플리커의 발생을 감마보정요소를 포함하는 선형모델로 모델링하고 이를 분석하여 제거하는 새로운 알고리즘을 제안한다. 제안하는 알고리즘은 플리커를 유발하는 게인과 오프셋 파라미터를 분리하고 게인 요소를 감마 보정으로 추정한다. 이 과정을 통하여 추정된 게인과 오프셋 플리커 영상 시퀸스에 역으로 적용하여 플리커를 제거한다. 제안하는 방법의 객관적인 성능을 보이기 위해 움직임이 없는 인위적인 테스트 영상 시퀸스에 대해 실험한 결과와 움직임이 있는 실제 영상 시퀸스에 적용한 결과를 제시하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1769-1774
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• 2006

A fully integrated inline OLED production system is presented. The performance of PLED devices that are encapsulated with a thin film multilayer stack are compared to conventionally encapsulated devices with glas/dessicant protection. The observed luminance decay is the same in both cases. The lifetime performance of the thin film encapsulation is measured and critical parameters are discussed. The first smOLED devices produced on the OTB equipment are presented and comparison with other smOLED devices shows very good results.