• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1077-1079
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• 2008

Nanoparticles-induced vertical alignment (NIVA) in the liquid crystal (LC) devices was observed and has been applied successfully on fabricating the hybrid-aligned nematic LC cells and guest-host LC cells. In this talk, we will discuss the characteristics of the electric and optical properties of NIVA-LC cells with different dopant concentrations and demonstrate that nanoparticles can be spin-coated on the substrate at a low temperature.

• The Journal of the Korean dental association
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• v.56 no.9
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• pp.512-520
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• 2018

As the demand for natural and beautiful smiles increases, the demand for anterior aesthetic treatment is increasing. Orthodontic treatment is often necessary for esthetic, healthy and natural treatment outcome. Particularly, in the case of middle-aged patients, minor tooth movement limited to anterior teeth is more effective than comprehensive orthodontic treatment which requires a long-term treatment period. Clinician who is in charge of aesthetic dentistry should have the ability to select a case that can be treated with partial orthodontic treatment and to determine the most effective treatment method. This article provides decision flowchart for case selection and choosing the best treatment modality for anterior teeth alignment.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1605-1608
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• 2006

The contrast ratio, brightness, and uniformity of S-IPS panel, whose alignment process was employed by ion-beam-alignment (IBA) technology, were improved significantly compared with the convention rubbing's panel, because the light leakage has been reduced in dark state effectively. The IBA technology could generate a panel whose pretilt angle was stable and low after post-treatment process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1144-1148
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• 2006

We have investigated liquid crystal (LC) aligning capabilities and electro-optical (EO) characteristics of transparent electrodes as Al-doped ZnO (AZO) substituting indium tin oxide (ITO). The experiment results show that a uniform vertical LC alignment on AZO electrodes based on a rubbed polyimide (PI) surface were achieved. A high pretilt angle of about $88^{\circ}$ was obtained. EO performances of the VA cell on rubbed PI surfaces with AZO electrodes are almost the same as that of the VA cell with ITO electrodes. These results appeared that AZO electrodes as transparent electrodes of LCDs could substitute ITO electrodes.

• Transactions on Electrical and Electronic Materials
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• v.3 no.2
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• pp.1-5
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• 2002

Alignment effects for nematic liquid crystal (NLC) and electro-optical (EO) characteristics of the ion beam (IB) aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the diamond-like carbon (DLC) thin film surface were studied. A high pretilt angle of 3.5$^{\circ}$ in NLC by ion beam exposure on the DLC thin film layer can be measured. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the DLC thin film surface for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1395-1397
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• 1998

In this paper, we studied the liquid crystal(LC) alignment and generation of pretilt angle in nematic (N) LC with oblique p-wave polarized ultraviolet (UV) light irradiation on the two kinds of the polyimide (PI) surface. The monodomain alignment of NLC is obtained with oblique p-wave polarized UV light irradiated on PI surface at 5$\sim$60min. We obtained that the pretilt angles of the NLC is generated about $2.1^{\circ}$ with angle of incidence of $30^{\circ}$ at 20min. Also, the pretilt angle of NLC decreases with increasing the imidization temperature on PI surface.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.173-173
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• 2010

We proposed viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. In the device, single pixel is separated into two regions, named as main pixel for displaying images and sub pixel for viewing angle control. In sub pixel region, add the common electrode on the top substrate and the initial alignment of liquid crystal is Hybrid Alignment Nematic (HAN) state. In conclusion, we suggested that the device has high aperture ratio characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.142-146
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• 1991

In order to develope transfer alignment algorithm which achieves accurate initial alignment of slave strapdown inertial navigation system(SDINS) of a missle using master SDINS of mobile launchers third-order suboptimal filter is constructed to estimate the transformation matrix between two SDINS coordinates. In Kalman Filter formulation, the measurement equation uses that of accelerometer when stationary, and is replaced by that of gyroscope when elevating the missle. This switching method is applied to increase the degree of observability and to remove the error generated by lever arm effect. Simulation results show that the azimuth transfer error is about 0.3 mrad, and confirm that this scheme has a potential for real application.

• Fibers and Polymers
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• v.2 no.1
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• pp.123-130
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• 2001

Photoresponsive side chain copolymer and homopolymer containing an aminonitroazobenzene were synthesized for studying photoisomerization behavior and photo-induced anisotropy. Trans-to-cis photoisomerization was observed under the exposure of a circularly polarized visible light with UV-Vis absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532nm. Polarized absorption spectroscopy was employed to investigate the anisotropy of the polymer film during irradiationg of the excitation light. Layers of two photosensitive polymers were used for aligning liquid crystal(LC) molecules instead of one of the rubbed polyimide layers in the conventional twisted nematic cell. For producing homogeneous alignment of a nematic LC molecule, a linearly polarized light was exposed to the films of two polymers. The stability of the LC alignment upon the linearly polarized light exposure was also studied.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.987-991
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• 2003

Ferrule is widely used as fiber optic connecters. In fiber-optic communications, the shape accuracy such as coaxiality and cylindricity of ferrule affects insertion loss. When coaxial grinding of ferrule supported by two pin, pin alignment and chucking accuracy are very important. In this research, the kinematic behavior of the ferrule center is investigated in the case where cone-shaped center pins and round circle holes which make contact with each other near the edge of the holes, using homeogenous coordinate transformation and numerical analysis. The obtained results are as follows: The alignment errors between center holes cause a sinusoidal displacement of ferrule. And the maximum displacement of ferrule centers increase in proportion to the center pin angle. The relationship between center pins displacement in coaxial grinding and grinding accuracy was explained.