• Journal of Information Display
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• v.7 no.3
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• pp.19-22
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• 2006

White polymeric light-emitting devices (WPLEDs) have been fabricated from polyfluorene-based (PFO) blue and MEH-PPV polymer blending systems. A device structure of ITO / PEDOT:PSS / Blending polymer / Blue polymer / LiF / Al was employed. This structure of double emission layers showed significant improvement of white color shift phenomenon. A current efficiency of 4.67 cd/A (3,900 $cd/m^{2}$, 6.4 V) and a brightness value of 17,600 $cd/m^{2}$ at 9.4 V with (0.34, 0.35) CIE coordinates at 5 V and (0.29, 0.29) at 9 V were achieved achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.514-516
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• 2003

We have fabricated an air stable blue emitting organic electroluminescent devices (OLEDs) with a carbazole based emitting molecule, Bis(3-N-ethylcarbazolyl)terephthalidene (BECP). Our device emits strong blue at 472 nm with the luminance efficiency of near 1 lm/W at a voltage and current density of 8 V and 5.7 mA/cm2, respectively, reaching the brightness up to 5000 cd/m2 at 270 mA/cm2. Finally, in order to tune the emission color from blue to green, we have used Bis(3-N-ethylcarbazolyl)cynoterephthalidene (BECCP), a derivative of BECP by adding cyno group in side chain, and compared the electroluminscence (EL) of OLEDS prepared by BECCP to that of BECP based OLEDs.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.177-185
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• 2007

The temperature and soot of the visualized diesel engine's turbulent flow of flame was qualitatively measured. In combustion chamber, in order to judge the affect that the swirl has on the in-cylinder's current, was used two different heads with different values. Using the high speed camera, and the results were analyzed using the heat release rate produced by the pressure sensor. In order to measure the temperature and soot of the turbulent flames like that of the diesel flames two color methods were used temperature and the soot of the flames according to the conditions through analyzing the two wavelengths of the flames. It was possible to measure the highest temperature of the non-swirl head visualized engine which is approximately 2400K, and that swirl head engine managed up to 2100K. With respect to the visualized diesel engine soot, we got the grasp of the KL factor which bears the qualitative information of soot. This study is dedicated to suggesting the possibility of measuring not only the temperature but also soot of the diffusion flame of the diesel engine turbulent flames through such method.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.709-714
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• 2022

The color change of the success of the steam sterilization indicator used in steam sterilization is currently being read by relying on the human eye. The result of color change on the success of sterilization can only be accurately read and judged by trained personnel. Developed an automatic reading system for steam sterilization indicators for the current human-dependent system, and developed an automatic reading device system for reading methods that were previously relied on with the human eye to develop a system that is more accurate and easier for anyone to read.

• Current Optics and Photonics
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• v.7 no.5
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• pp.485-495
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• 2023

The pixel size in high-resolution complementary metal-oxide-semiconductor (CMOS) image sensors continues to shrink due to chip size limitations. However, the pixel pitch's miniaturization causes deterioration of optical performance. As one solution, a quad color filter (CF) array with pixel binning has been developed to enhance sensitivity. For high sensitivity, the microlens structure also needs to be optimized as the CF arrays change. In this paper, the covered microlens, which consist of four microlenses covered by one large microlens, are proposed for the quad CF array in the backside illumination pixel structure. To evaluate the optical performance, the suggested microlens structure was simulated from 0.5 ㎛ to 1.0 ㎛ pixels at the center and edge of the sensors. Moreover, all pixel structures were compared with and without in-pixel deep trench isolation (DTI), which works to distribute incident light uniformly into each photodiode. The suggested structure was evaluated with an optical simulation using the finite-difference time-domain method for numerical analysis of the optical characteristics. Compared to the conventional microlens, the suggested microlens show 29.1% and 33.9% maximum enhancement of sensitivity at the center and edge of the sensor, respectively. Therefore, the covered microlens demonstrated the highly sensitive image sensor with a quad CF array.

• Science of Emotion and Sensibility
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• v.19 no.2
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• pp.55-66
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• 2016

This study was aimed to characterize the color of cotton fabric dyed with three different natural resources such as persimmon, citrus, and brown algae and to propose new trend color themes for fashion color planning for newborn and toddler wear. A variety of color shades by dyeing cotton fabric with persimmon, citrus, and brown algae respectively was obtained and each color was also determined if it could be matched with one of Pantone TPX considering authorized color trends for 2016 Spring/Summer. Finally a group of new trend color theme for 2016S/S newborn and toddler wear were proposed for naturally dyed cotton fabric. As results, the three natural dyeing resources gave color gamut with hue ranging from Purple Blue to Green Yellow and with tones including pale, light grayish, soft, grayish, and dull by their single and compound dyeing. A total of 23 colors matched to Pantone TPX were considered for the fashion color planning by natural dyeing. The selected natural colors were grouped as three different color ways and thereafter the color ways were differentiated in terms of representative color sensibility by using subjective evaluation. Finally three characterized color themes were proposed as 'Serenity', 'Juicy', and 'Fancy', each of which has tried to express differentiated feeling of each natural resources for dyeing, to follow up to global color trends, and to contribute to newborn and toddler wear's own requirements and marketability. These results suggest that natural dyeing colors could be applied into fashion color planning in current fashion industries in order to produce more sensible and emotional design of fashion goods using natural dyeing.

• The Journal of the Korean dental association
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• v.52 no.9
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• pp.541-549
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• 2014

The restorative treatment using titanium implants has become a standard procedures in everyday clinical practice. However, there are several concerns about the use of titanium as a materials. Above all, the grayish metal color provokes esthetic problems when the soft tissue around the implants is not optimal. Recently, zirconia has been emerging as an alternative to titanium due to its white color and superior physicochemical properties. In this paper, the current findings about zirconia implants was reviewed based on the results from animal and clinical experiments. In addition, the immediate implantation protocols using the natural tooth form zirconia implants was introduced as a novel procedures and future perspectives were discussed.

• Journal of Korean Society of Water and Wastewater
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• v.9 no.2
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• pp.77-83
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• 1995

The effluent from conventional nightsoil treatment plants contains nutrients, color and chlorides, in addition to residual organics and suspended solids, and thereby causes substantial pollution problems in receving water resources. In order to verify the usefullness of electrolysis in removing those residual pollutants from such conventional nightsoil treatment plant effluent, a bench scale experiment was conducted using sufficiently dilluted human nightsoil as experiment feeds. The result showed mean removals of 45% of total phosphorus and 85% of color, in addition 87% of residual BOD, 47% of residual COD and 85% of residual SS. The optimum electric current was found to be 15 ampere and the optimum hydraulic residence time 21/2 hour.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.7
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• pp.597-603
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• 2004

In retrieving large database of image data, the clustering is essential for fast retrieval. However, it is difficult to cluster a number of image data adequately. Moreover, current retrieval methods using similarities are uncertain of retrieval accuracy and take much retrieving time. In this paper, a suggested image retrieval system combines Fuzzy ART neural network algorithm to reinforce defects and to support them efficiently. This image retrieval system takes color and texture as specific feature required in retrieval system and normalizes each of them. We adapt Fuzzy ART algorithm as neural network which receive normalized input-vector and propose improved Fuzzy ART algorithm. The result of implementation with 200 image data shows approximately retrieval ratio of 83%.

• Journal of The Korean Astronomical Society
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• v.47 no.4
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• pp.153-158
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• 2014

I show that the standard microlensing technique to measure the angular radius of a star using color/surface-brightness relations can be inverted, via late-time proper motion measurements, to calibrate these relations. The method is especially useful for very metal-rich stars because such stars are in short supply in the solar neighborhood where other methods are most effective, but very abundant in Galactic bulge microlensing fields. I provide a list of eight spectroscopically identified high-metallicity bulge stars with the requisite finite-source effects, seven of which will be suitable calibrators when the Giant Magellan Telescope comes on line. Many more such sources can be extracted from current and future microlensing surveys.