• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1163-1166
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• 2004

Cinnamate group is well-known for the dimerization reaction by ultra-violet irradiation and cinnamate polymers are studied for photo-alignment materials. The cinnamate groups of flexible polymer are found to produce LC alignment parallel to polarization direction of ultra-violet light, which is contrary to the LC orientation on conventional cinnamate polymers. The un-reacted cinnamate groups in the flexible polymer are also found to participate in cycloadducts formation by additional thermal reaction that preserves the orientation of cycloadducts, leading to the enhancement of thermal stability of LC alignment.

• ETRI Journal
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• 제30권2호
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• pp.308-314
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• 2008

In this paper, we describe the fabrication of 3.5-inch QCIF active matrix organic light emitting display (AMOLED) panels driven by thin film transistors, which are produced by an ultra-low-temperature polycrystalline silicon process on plastic substrates. The over all processing scheme and technical details are discussed from the viewpoint of mechanical stability and display performance. New ideas, such as a new triple-layered metal gate structure to lower leakage current and organic layers for electrical passivation and stress reduction are highlighted. The operation of a 3.5-inch QCIF AMOLED is also demonstrated.

• 한국염색가공학회지
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• 제24권3호
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• pp.180-188
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• 2012

Following the reported study that showed the dyeability of diamino-anthraquinoid blue dyes substituted with relatively shorter alkyl groups, the longer aliphatic substituents than pentyl group were examined in terms of the color strength and fastness properties toward UHMWPE fibers. The color strength was increased up to pentyl group and then gradually decreased. However, the fastness properties were improved continuously to octyl group which was the longest alkyl substituent in this study. The most effective maximum color strength was obtained at $130^{\circ}C$ for 2 hours with 3% owf of dyes. The overall fastnesses to washing, rubbing, and light were good enough for practical uses.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.563-564
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• 2009

Ultra-High Performance Concrete (UHPC) compared to normal concrete is exhibiting extremely high strength characteristics with compressive strength and tensile strength reaching 200MPa and 15MPa, respectively. The mechanical characteristics of UHPC can be thus exploited advantageously in the construction of structure through the reduction of the cross-sectional area and fabrication of slim and light-weight of the structural members. In the case where the structural member is made of UHPC, the occurrence of crack can be prevented by releasing the restraint provided by the form in due time. This research performs parametric study of the failure characteristics of concrete such as failure energy and softening curve suggested by the viscous crack model approximating the failure of concrete. The scope of this research contains the results of tests performed to investigate the strength of UHPC during early elapsed time.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1327-1330
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• 2008

A novel fiber optic solution is provided to efficiently mix visible colors. Full color synthesis was achieved utilizing a novel $3{\times}1$ hard polymer clad fiber (HPCF) coupler along with red, green and blue (RGB) light emitting diode (LED) primaries. Varying the intensities of RGB LEDs that are coupled to three input ports, the device rendered a full color with an ultra wide CIE color gamut. Potential applications in pica-projection displays and LED backlights will be discussed.

• Design & Manufacturing
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• 제10권3호
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• pp.8-13
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• 2016

Despite technological advance, there have been several troubles in photo reaction injection molding (photo RIM) to produce ultra thin light guide panels (LGPs). In this study, micro leakage problem at cavity edge during photo RIM was investigated numerically. In order to obtain optimal processing conditions, we regulated inlet pressure of injected resin at the cavity edge and figured out micro leakage behaviors. At low inlet pressure (less than 100 Pa), though the micro leakage problem was not occurred, another problem, short shot due to not enough driving force, was appeared More than 1,000 Pa of the inlet pressure, injected resin was rapidly leaked through the micro gap at the cavity edge. Finally, we obtained optimal inlet pressure around 600 ~ 1,000 Pa. At this region, injected resin fully filled the cavity without micro leakage behavior. Based on the present study, further comparative investigations with experimental photo RIM should be performed to find optimal processing conditions for produce ultra thin LGPs.

• 천문학회보
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• 제42권1호
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• pp.44.4-45
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• 2017

We report the first detection of RR Lyrae variable stars in the Crater II dwarf galaxy, a recently discovered ultra-faint satellite of the Milky Way. Based on B, V time series photometry obtained with the Korea Microlensing Telescope Network (KMTNet) at CTIO, Chile, we have identified ~45 fundamental-mode (ab-type) and ~2 first-overtone (c-type) RR Lyrae stars by adopting template light-curve fitting method. Our preliminary analysis suggests an Oosterhoff-intermediate classification of this galaxy from the mean period of the RRab stars, <$P_{ab}$> ${\simeq}0.63$ days, and the location of them on the period-amplitude diagram. We discuss the properties of the RR Lyare stars in this galaxy.

• 한국염색가공학회지
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• 제14권2호
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• pp.77-77
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• 2002

Cotton fabrics dipped in cationic agent(3-chloro-2-hydroxypropyl trimethyl ammonium chloride) were irradiated with deep Ultra Violet Rays(UV), in the region of UV-C using the low pressure mercury lamp. The chemical changes of cationized cotton fabric surfaces were investigated by FT-IR analysis. The dyeabilities of the irradiated portions were investigated by dyeing with acid dyes. Deep UV(UV-C) irradiation broke O-H bonds in cotton fiber and oxidized the fibers. The dyeability of the UV irradiated portion were different from that of the portion not irradiated. Various pattern were gained from one bath dig dyeing by pattern mask. The tensile strengths of cotton fabrics were decreased in the UV irradiated portion. Washing fastness of cotton dyeings were good about 3∼4 grade and light fastness were fair about 2∼3 grade.

• 한국염색가공학회지
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• 제14권2호
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• pp.1-8
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• 2002

Cotton fabrics dipped in cationic agent(3-chloro-2-hydroxypropyl trimethyl ammonium chloride) were irradiated with deep Ultra Violet Rays(UV), in the region of UV-C using the low pressure mercury lamp. The chemical changes of cationized cotton fabric surfaces were investigated by FT-IR analysis. The dyeabilities of the irradiated portions were investigated by dyeing with acid dyes. Deep UV(UV-C) irradiation broke O-H bonds in cotton fiber and oxidized the fibers. The dyeability of the UV irradiated portion were different from that of the portion not irradiated. Various pattern were gained from one bath dig dyeing by pattern mask. The tensile strengths of cotton fabrics were decreased in the UV irradiated portion. Washing fastness of cotton dyeings were good about 3∼4 grade and light fastness were fair about 2∼3 grade.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.149-149
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• 2010

The origin of the inhomogeneous distribution of photoluminescence (PL) peak wavelength on a commercial 2" GaN wafer for green light emitting diode has been investigated by wide momentum transfer (Q) range x-ray diffraction (XRD) profile of InGaN/GaN multiple quantum wells. Near the GaN (0004) Bragg peak, wide-Q range XRD (${\Delta}Q$ > $1.4{\AA}-1$) was measured along the growth direction. Wide-Q XRD gives precise and direct information of ultra-thin InGaN quantum well structure. Based on the QW structural information, the variation of PL spectra can be explained by the combined effect of temperature gradient and slightly uneven flow of atomic sources during the QW growth. In narrow variations of indium composition and thickness of QW, an effective indium composition can be a good character to match structural data to PL spectra.