• Polymer(Korea)
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• v.39 no.1
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• pp.174-179
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• 2015

Alignments of photo-reactive mesogen were induced using bare glass substrates without a polymer alignment layer. It was found by using polarized FTIR spectroscopy, polarized microscopy, and birefringence measurement experiments that the reactive mesogen could be aligned along the rubbing direction although the glass substrate without an alignment layer was used. The induction mechanism of the rubbed bare glass is ascribed to that polymers from rubbing clothes are coated on the glass substrate along the rubbing direction and lead the alignment of liquid crystals through intermolecular interactions.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.172-177
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• 2021

The HUD (Head-up Display) device for vehicles has gradually been advanced in connection with ADAS (Advanced Driver Assistant System) for the safety and the convenience of driving. In this paper, the major features (e.g. speed, RPM, etc.) of vehicles is received through the ECU and the route information is received through the navigating API, configurating the integrated GUI. And, the optical system is configured based on DLP (Digital Light Processing) to evaluate the visibility depending on the resolution change of the GUI. The IoT HUD system proposed in this paper has the scalability to flexibly add not only the ECU but also various cloud-based driving-related information.

• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.368-372
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• 2011

An advanced microcolumn is proposed which adopts a modified einzel lens structure. The newly designed einzel lens is composed of four electrodes. The two center electrodes are specially designed electrostatic quadrupole (EQ) einzel lenses having keyhole instead of circular apertures. We constructed the advanced microcolumn with the EQ-einzel lenses, and operated the newly designed microcolumn in single lens mode and double-lens mode. The preliminary results show that the EQ-einzel lens can improve the performance of the micro-column for large sample applications.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.417-420
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• 2003

Exitech has developed a range of advanced laser ablation tools for the manufacture of display device structures on super large glass and plastic substrates. Technical information and cost of ownership data about these tools together with key areas of application are presented

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.09a
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• pp.151-154
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• 2005

In this paper, we present the enhanced performance of resistive RAM devices with multi-step deposited and annealed oxides. By using multi-step deposition and low temperature multi-step annealins, forming-free Re-RAM is achieved with lower operation voltages and larger resistive ratio than those of conventional Re-RAM with typical single deposited oxide.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.559-565
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• 2011

The following noble series of statistical copolymers, poly[(2-(3-thienyl)ethanol n-butoxycarbonylmethylurethane)-co-3-hexylthiophene] (PURET-co-P3HT), were synthesized by the chemical dehydrogenation method using anhydrous $FeCl_3$. The structure and electro-optical properties of these copolymers were characterized using $^1H$-NMR, UV-visible spectroscopy, elemental analysis, GPC, DSC, TGA, photoluminescence (PL), and cyclic voltammetry (CV). The statistical copolymers, PURET-co-P3HT (1:0, 2:1, 1:1, 1:2, 1:3), were soluble in common organic solvents and easily spin coated onto indium-tin oxide (ITO) coated glass substrates. Hybrid bulk heterojunction photovoltaic cells with an ITO/G-PEDOT/PURET-co-P3HT:PCBM:Ag nanowires/$TiO_x$/Al configuration were fabricated, and the photovoltaic cells using PURET-co-P3HT (1:2) showed the best photovoltaic performance compared with those using PURET-co-P3HT (1:0, 2:1, 1:1, 1:3). The optimal hybrid bulk heterojunction photovoltaic cell exhibits a power conversion efficiency (PCE) of 1.58% ($V_{oc}$ = 0.82 V, $J_{sc}$ = 5.58, FF = 0.35) with PURET-co-P3HT (1:2) measured by using an AM 1.5 G irradiation (100 mW/$cm^2$) on an Oriel Xenon solar simulator (Oriel 300 W).

• Journal of Information Display
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• v.12 no.1
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• pp.47-50
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• 2011

Highly stable amorphous indium.gallium.zinc-oxide (a-IGZO) thin-film transistors (TFTs) were fabricated with an etchstopper and via-hole structure. The TFTs exhibited 40 $cm^2$/V s field-effect mobility and a 0.21 V/dec gate voltage swing. Gate-bias stress induced a negligible threshold voltage shift (${\Delta}V_{th}$) at room temperature. The excellent stability is attribute to the via-hole and etch-stopper structure, in which, the source/drain metal contacts the active a-IGZO layer through two via holes (one on each side), resulting in minimized damage to the a-IGZO layer during the plasma etching of the source/drain metal. The comparison of the effects of the DC and AC stress on the performance of the TFTs at $60^{\circ}C$ showed that there was a smaller ${\Delta}V_{th}$ in the AC stress compared with the DC stress for the same effective stress time, indicating that the trappin of the carriers at the active layer-gate insulator interface was the dominant degradation mechanism.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.167-173
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• 2013

A series of highly efficient red phosphorescent heteroleptic iridium(III) complexes 1-6 containing two cyclometalating 2-(2,4-substitued phenyl)quinoxaline ligands and one chromophoric ancillary ligand were synthesized: (pqx)$_2Ir$(mprz) (1), (dmpqx)$_2Ir$(mprz) (2), (dfpqx)$_2Ir$(mprz) (3), (pqx)$_2Ir$(prz) (4), (dmpqx)$_2Ir$(prz) (5), (dfpqx)$_2Ir$(prz) (6), where pqx = 2-phenylquinoxaline, dfpqx = 2-(2,4-diflourophenyl)quinoxaline, dmpqx = 2-(2,4-dimethoxyphenyl)quinoxaline, prz = 2-pyrazinecarboxylate and mprz = 5-methyl-2-pyrazinecarboxylate. The absorption, emission, electrochemical and thermal properties of the complexes were evaluated for potential applications to organic light-emitting diodes (OLEDs). The structure of complex 2 was also determined by single-crystal X-ray diffraction analysis. Complex 2 exhibited distorted octahedral geometry around the iridium metal ion, for which 2-(2,4-dimethoxyphenyl)quinoxaline N atoms and C atoms of orthometalated phenyl groups are located at the mutual trans and cis-positions, respectively. The emission spectra of the complexes are governed largely by the nature of the cyclometalating ligand, and the phosphorescent peak wavelengths can be tuned from 588 to 630 nm with high quantum efficiencies of 0.64 to 0.86. Cyclic voltammetry revealed irreversible metal-centered oxidation with potentials in the range of 1.16 to 1.89 V as well as two quasi-reversible reduction waves with potentials ranging from -0.94 to -1.54 V due to the sequential addition of two electrons to the more electron-accepting heterocyclic portion of two distinctive cyclometalated C^N ligands.

• Journal of Information Display
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• v.13 no.3
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• pp.101-106
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• 2012

This study was conducted to enhance the cubic effect by representing an image with a sense of three-dimensional (3D) depth, using chromostereopsis, among the characteristics of human visual perception. An algorithm that enhances the cubic effect, based on the theory that the cubic effect of the chromostereoptic effect and the chromostereoptic reversal effect depends on the lightness of the background, classifies the layers of the 3D image input into the foreground, middle, and background layers according to the depth of the image input. It suits the characteristics of human visual perception because it controls the color factor that was adaptively detected through experiments on each layer; and it can achieve an enhanced cubic effect that is suitable for the characteristics of the image input.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2494-2498
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• 2012

Preparation of several new spirocyclic mercapto derivatives is described. Thiol protection on multi-carbonyl compounds allows of high sulfur content necessary to induce high refractive index. Condensation of 1,3-dimercapto-2-propanol and cyclohexanone followed by successive oxidation and thioacetalization affords a dispirocycle with four sulfurs. Selective S,S-protection of cyclohexane-1,4-dione is achieved with 1,3-dimercapto-2-propanol and 2,3-dimercapto-1-propanol to provide dispirocycles with four sulfurs. Olefine-oxidation of norbornene gives a useful dialdehyde intermediate which is transformed to 1,3-dithiolane for a linearly-bound-cyclic molecule. Refractive index of linearly-bound-cycles was below 1.60 and dispirocycles exhibited high refractive index of 1.57-1.69.