• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1529-1530
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• 2007

The manganese co-doped $Ca_8Mg_1(SiO_4)_4Cl_2:Eu^{2+}$,$Mn^{2+}$ phosphor was synthesized by solid-state reaction and its photoluminescence characteristics were investigated. The synthesized phosphor show two emission spetrums: green band of 512nm and yellow band of 550nm. White light-emitting diodes (LEDs) were fabricated through combination of a 405nm-emitting InGaN chip and a synthesis phosphor in a single package. Under 20mA current, its CIE chromaticity coordinates are x=0.40 and y=0.45 and a color temperature of 4053K.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.776-778
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• 1998

Electrical and optical characteristics of Powder type EL display(P-ELD) in this study are described, In experimental results of V-J, current are increased with increasing the frequency and voltage. Luminance was increased with frequency. This is due to the positive space charge formed to cathode region. Lumiance at 150V, 20 kHz has $840\;cd/m^2$. This tendency is due to the decrease of capacitive reactance in insulator layer. Uniformity of P-ELD shows 97%. CIE chromaticity with increasing frequency are shifted toward blue color. It can be explained in tenn of the difference of recombination energy.

• Journal of the Korean Solar Energy Society
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• v.23 no.1
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• pp.68-75
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• 2003

본 논문에서는 파랑, 녹색, 호박색 빨강색, 백색 등 고휘도 5mm LED(light emitting diode)의 기본적인 분광분포(SED: spectral energy distribution) 특성을 분석하였으며, LED램프의 중요한 광학 특성인 광속, 효율 피크 파장$({\lambda}p)$, 가중치 평균 파장, 반치폭(FWHM, $\Delta\lambda$), 색도좌표, 주 파장, 자극순도(Pe)와 휘도순도(Pc) 등을 측정 및 실험하였다. 제시된 LED램프의 특성 데이터는 앞으로 LED램프를 사용한 새로운 조명등기구를 개발하는데 많은 도움을 줄 것이며, 이러한 측정 데이터들은 조명용 광원으로서 LED램프의 사용 대체 가능성을 나타낸다.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1075-1078
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• 2006

New iridium complex was synthesized and demonstrated a deep red light emission in organic light-emitting diodes (OLEDs). The maximum luminance of 8320 cd/m2 at 15 V and the luminance efficiency of 2.5 cd/A at 20 mA/cm2 were achieved. The peak wavelength of the electroluminescence was at 626 nm with the CIE coordinates of (0.69, 0.30), and the device also showed a stable color chromaticity with various voltages.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.257-259
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• 2002

As a new host material for a red phosphor for PDP applications, has studied (Y,Gd)$Al_3(BO_3)_4$ which gives non-centrosymmetric sites for $Eu^{3+}$ activators. Vacuum ultraviolet (VUV) excitation spectrum of new red phosphor (Y,Gd)$Al_3(BO_3)_4$:$Eu^{3+}$ has two broad bands. One band with the absorption edge at ca. 168 nm is the band-gap absorption of aluminoborate and the other broad band centered 240 nm is the charge transfer transition between $Eu^{3+}$ and the neighboring oxygen anions. The PL spectrum shows the strongest emission at 617 nm due to the electric dipole $^5D_0{\rightarrow}^7F_2$ transition of $Eu^{3+}$, whose luminescent chromaticity is (0.67, 0.33).

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.369-371
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• 2012

Shadow detection and elimination is a critical issue in vision-based system to improve the detection performance of moving objects. However, traditional algorithms are useless at night time because they used the chromaticity and brightness information from the color image sequence. To obtain the high detection performance, we can use the thermal camera and there are shadows by the heat not the light. We proposed a novel algorithm to detect and eliminate the shadows using the thermal intensity and the locality property. By combining two results of the intensity-based and locality-based, we can detect the shadows by the heat and improve the detection performance of moving object.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.211-215
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• 2002

This study was intended to investigate the optimal soaking time of glutinous rice for making jujube Injeolmi, a kind of traditional Korean glutinous rice cake. The jujube Injeolmi was prepared with glutinous rice soaked for various times (2, 4, 6, 8, 10 hr), and the moisture content, chromaticity, sensory qualities and mechanical qualities were measured while storing them up to 72 hr at 20$^{\circ}C$. The moisture content and L-value of jujube Injeolmi were the highest at 8-hr soaking. The a-value was the highest at 6-hr soaking. The hardness was maintained the lowest at the 8-hr soaked sample during storage. The cohesiveness and springiness were not significantly affected by the soaking time. The gumminess was significantly different among the samples during storage. The results of sensory evaluation showed that jujube Injeolmi had the best color at 4-hr soaking and the highest sweetness at 6-hr soaking. The 8-hr soaked glutinous rice gave the highest level of softness, chewiness and moistness in the sample, therefore, 8-hr soaking appeared to be the most desirable method for making jujube Ingeolmi.

• Transactions on Electrical and Electronic Materials
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• v.6 no.3
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• pp.91-96
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• 2005

We report the efficient red light-emitting diodes based on the fluorescent dye 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTI) and 5,6,11,12-tetraphenyl naphthacene (rubrene) codoped in the tris(8-hydroxyquinoline)aluminum $(Alq_3)$. Luminance efficiency of 2.2 cd/A with a Commission International De L'Eclairage (CIE) chromaticity coordinate of x, y = (0.640, 0:350) are achieved at the driving current density of $20\;mA/cm^2$. Adding the rubrene to the DCJTI in tris(8-hydroxyquinoline)aluminum $(Alq_3)$, the red color purity and luminance efficiency improved comparing to the DCJTI only doped devices because the rubrene molecules assist the polarization effect of DCJTI by molecular interaction and enhance the energy transfer from $(Alq_3)$ to DCJTI.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.76-80
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• 2003

Recently as new digital media like High Definition Television (HDTV) have been made popularization. However In case of image quality characteristics of AC PDP, the problem especially raised is 'image sticking' phenomenon, the phenomenon that the previously displayed pattern still remains after the image in realizing high picture quality. In this paper, Image sticking Phenomena observed in AC PDP are defined and classified, these effects are analyzed as luminance, color purity through chromaticity diagram and firing voltage state using light waveform.

• Korean Journal of Plant Resources
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• v.20 no.3
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• pp.247-250
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• 2007

This study was performed to investigate the discrimination of Angelica gigas, Angelica acutiloba and Angelica sinensis on the treatment of chromaticity and colorfastness. Angelica gigantis root has been used as a Korean traditional medicine for the treatment of woman disease. Natural dyes give us many great benefits, including diversified color, but no pollution. These studies were carried out acetate iron, dichloride copper and alum with a mordant to ramie fabric. The ramie fabric was dyed with Angelica gigas, Angelica acutiloba and Angelica sinensis. The results of experiment showed as follows: In discrimination by dyeing, the colors of Angelica acutiloba and Angelica sinensis were very similar, but that of Angelica gigas was different. There were no differences among colors of materials using non-mordant. But dyeing with iron acetate and copper dichloride were showed dark in Angelica gigas than other angelica species.