• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.576-582
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• 2011

In this paper, we proposed the improved Advanced Detail Enhancement algorithm that improve the blurring by the lossy compression with CODEC and reduce the ringing artifacts in restoration. The conventional algorithm needs much amount of the process by the use of RGB color space. To improve this, we only used the luminance value in YCbCr color space. We verified that the performance of the improved algorithm with Y color value, the luminance value, is equal to the conventional algorithm with RGB color value and that the operation time of the improved is shorter about 24% than the conventional through the measurement of the operation time with Kodak standard images.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.411-412
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• 2008

We have studied a property change of organic light-emitting diodes (OLED) due to an indium tin oxide (ITO) surface reformation. The characteristics of OLED were improved by oxygen plasma processing of an ITO in this work. ITO is widely used as a transparent electrode in light-emitting devices, and the OLED device performance is sensitive to the surface properties of the ITO. The OLED devices with the structure of ITO/TPD(50nm)/$Alq_3$(70nm)/LiF(0.5nm)/Al(100nm) were fabricated, and the surface properties of ITO were investigated by using various characterization techniques. The oxygen plasma process of an ITO was processed by using RF power of 125W and oxygen partial pressure of $2\times10^{-2}$ Torr. The oxygen plasma processing of an ITO processed for 0/1/2/3/4min. Current-voltage-luminance characteristics of the devices show that turn-on voltage is 4V for 2min device and the luminance reaches about 27,000cd/$m^2$ for 4min device. The current efficiency shows that 3min device becomes saturated to be about 8cd/ A. They show that emission was from the $Alq_3$ layer, because the peak wavelength is about 525nm. View angle-dependent emission spectra show that the emission intensity decreases as the angle increases.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.19-28
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• 2005

Real surround viewing conditions in watching the color display devices such as TV and PC monitor are quite different from the standard viewing conditions. Human visual system is adapted chromatically under the different viewing conditions in luminance levels and chromaticity of illuminants. Accordingly, the reproduced colors of the same chromaticity will appear as quite different color. Therefore, it is necessary that the displayed colors are reproduced to be appeared as the original colors in the standard viewing conditions. In this paper, we propose a chromatic adaptation model for the variations of the surround illuminants' chromaticity under the same luminance conditions. In proposed chromatic adaptation model, we calculate each gain of L, M, and S as nonlinear functions according to the chromaticity of the surround illuminants. And the optimal coefficients are obtained from the corresponding colors data of the Breneman's experiments. The proposed chromatic adaptation model is compared with the conventional chromatic adaptation models. In the experimental results, the proposed model has very good performance in the whole range of luminance levels. We also experimentally confirmed that the reproduced corresponding colors using the proposed chromatic adaptation are appeared as the original colors when the real surround viewing conditions are different from the standard viewing conditions.

• The KIPS Transactions:PartB
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• v.13B no.2 s.105
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• pp.77-82
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• 2006

Digital halftoning is the technique to obtain a bilevel-toned image from continuous-toned image. Among halftoning methods, the error diffusion method gives better subjective quality than other halftoning ones. But it also makes edges of objects blurred. To overcome the defect, we proposes the modified error diffusion to enhance the edges using the property that human vision perceives the local average luminance and doesn't perceive a little variation of the spatial variation. The proposed method computes a spatialactivity, which is the difference between a pixel luminance and the average of its $3{\times}3$ neighborhood pixels' Iuminance weighted according to the spatial positioning. The system also usesof edge enhancement (IEE), which is computed from the normalized spatial activitymultiplied by the average luminance. The IEE is added to the quantizer's input pixel and feeds into the halftoning quantizer. The quantizer produces the halftone image having the enhanced edge. The computer experimental results show that the proposed method produces clearer bilevel-toned images than conventional methodsand the edge of objects is preserved well. Also the performance of the preposed method is improved, compared with that of the conventional method by measuring the edge correlation and the local average accordance at some ranges of viewing distance.

• Fire Science and Engineering
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• v.31 no.5
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• pp.63-69
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• 2017

This study describes the development of a long-distance hose for ultra-high pressure operation, which can be used in conjunction with an ultra-high pressure pump and can be effectively applied to the fire suppression of high-rise buildings and a long, large tunnels. Also, it has phosphorescent properties, which can help to secure the withdrawal route of the fire-fighters when they are threatened by the fire. We developed an ultra-high pressure hose aiming at a pressure of 3 MPa and a flow rate of 2000 lpm and developed an ultra-high pressure fire hose that can withstand this very high pressure by using a double jacket, triple polyurethane coating and warf (Wp) of 52. In order to ensure the performance of the developed ultra-high pressure hose, its structure, appearance, leakage at high pressure, length and elongation were inspected by a certified certification agency, who also subjected it to a peeling test, friction test, breaking pressure test and free fall test. Also, it was studied in addition to the luminescent high-pressure hose for fire-fighting. In the phosphorescence test, the luminance measurement value was more than the reference value of the luminance test after 40 minutes, which confirmed that its performance was satisfactory for fire-fighting products. In the future, if such an ultra-high pressure fire hose were commercialized and applied in the field, it could contribute to securing improved fire suppression and safer exit from fires, as compared to the fire hoses currently used in the suppression of fires in skyscraper buildings and long tunnels.

• International Journal of Advanced Culture Technology
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• v.2 no.2
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• pp.1-6
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• 2014

In this paper, we propose an intelligent streetlight system that has a complex sensor module of temperature, humidity, luminance and motion detection and controlled by the fuzzy logic based central monitoring system in order to get flexible and precise manipulation of the streetlight system in USN environment. The proposed streetlight system provides low power consumption and high efficiency by using sensed data from the complex sensor module, which were collected, processed, and analyzed by the fuzzy logic based central monitoring system. The performance of the proposed streetlight system is to be evaluated by a simulation study in terms of power savings and safety at the fields constructed as a test-bed under several suggested scenarios. Finally, we know that the proposed intelligent streetlight system can maximize the energy savings efficiently with the fuzzy logic based central monitoring system and selective remote dimming control by connecting it to the wireless ubiquitous sensor network (USN) using a Zigbee module.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04c
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• pp.121-122
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• 2008

Blue emitting materials have been explored by various researchers. However, blue-emitting materials with high luminous efficiency, good color purity, and thermal stability are still much desired. In this study, we synthesized a new blue luminescent material, $SnDP(HPB)_2$ which is low molecular compound and thermal stability. The PL spectrum of $SnDP(HPB)_2$ was observed blue at the wavelength of 447nm. The ionization potential(IP) and the electron affinity(EA) of $SnDP(HPB)_2$ was measured to be 6.7 eV and 3.0 eV, respectively. The fundamental structure of the OLED was ITO/NPB/$SnDP(HPB)_2/Alq_3$/LiF/Al. As a Result, we obtained to enhance the performance of blue OLED.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.1-7
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• 2006

A light guided plate coupled with the micro Fresnel lens array(MFTA) is designed to improve the efficiency of the LCD backlight unit. Blazed Frenel lens and binary multi-level Fresnel lens are adapted for the MFLA. This type of MFLA can replace the prism sheet and diffuser sheet which are used for the conventional type of the LCD backlight unit. The luminance and uniformity are calculated to verify the performance of the MFLA type LCD backlight unit.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.777-782
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• 2014

This paper proposes an RGB to RGBY color conversion algorithm for liquid crystal display (LCD) using RGW pixel structure with two-field (yellow and blue) sequential driving method. The proposed algorithm preserves the hue and saturation of the original color by maintaining the RGB ratio, and it increases the luminance. The performance of the proposed RGBY conversion algorithm is verified using the MATLAB simulation with 24 images of Kodak lossless true color image suite. The simulation results of average color difference CIEDE2000 (${\delta}E^*_{00}$) and scaling factor are 0.99 and 1.89, respectively. These results indicate that the average brightness is increased 1.89 times compared to LCD using conventional RGB pixel structure, without increasing the power consumption and degrading the image quality.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.9
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• pp.70-77
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• 1998

A new method is proposed for the design of the dichroic mirrors in 3-LCD projection systems for color separation/composition. Rather than simply basing the color performance criterion on luminance or chromatic saturation only, the optimum design parameters can be found by maximizing the perceived color gamut in a 3-D uniform color space. In this method, the half-power wavelengths were optimized by maximizing the volume of the reproducible color gamut in a CIELUV uniform color space for 2 typical viewing conditions, with proper colorimetric analysis of color reproduction in 3-LCD projection systems.