• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.770-775
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• 2000

A new photo-polymer material of the copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy)chalcone-cholesteryl methacrylate) for homeotropic alignment was synthesized and the electro-optical (EO) performance for the photo-aligned vertical-aligned (VA)-LC display (LCD) was studied. Good thermal stabilities of synthesized copolymer were obtained by TGA(Thermogravimetric Analysis) measurement. Good voltage-transmittance (V-T) and response time characteristics for the photo-aligned VA-LCD with polarized UV exposure in oblique direction($\theta$$_{i}$=30$^{\circ}$) on a copolymer-1 (2%) surfaces for 1 min were observed. but, light leakage in the off-state was observed. Therefore, we achieved excellent V-T and response time characteristics for the photo-aligned VA-LCD with UV exposure on a copolymer-3 (30%) surfaces for 3 min.n.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.956-958
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• 1999

We designed and fabricated p-type MOSFETs with floating gate in n-type well lesion and examined their photo characteristics. The fabricated MOBFETs showed a high photo-respsonse characteristics, indicating a possibility as a photo sensor. The structures of MOSFETs were changed as to the number of gate and channel. As the number of channel increased, the induced current by light source s increased. However, the effect of the number of gate was negligble on the photo-response characteristics of the device.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.922-925
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• 1999

The Silylation photo-resist etch process was tested by Enhanced-ICP dry etcher. The comparison of the two process results of micro pattern etching with 0.25${\mu}{\textrm}{m}$ CD by E-ICP and ICP reveals that E-ICP has better quality than ICP The etch rate and the microloading effect was improved in E-ICP Especially, the problem of the lateral etch was improved in E-ICP.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.668-671
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• 2009

Photosensitive polyimide containing methoxy cinnamate derivatives as a photo-alignment layer is investigated. The anisotropy of alignment layer was induced by irradiation linearly polarized UV (LPUV). We studied the effect of the methoxy cinnamate groups on alignment LCs.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.4
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• pp.105-118
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• 2007

The purpose of this study is not only to compare between 'Opened Landscape' and 'Filtered Landscape' image and preference but also to suggests a guide line of planting design for progressive realization. For this, the image structures of photo-sketch simulation for parallax landscape have been investigated by Semantic Differential scale(S.D. scale) and the Factor analysis. The results could be summarized as follows. The results of S.D. scale values for landscape through parallax were greater than non-parallax landscape. The scenes through parallax were better preferred to direct view. Thus the results of photo-sketch simulation test support the expected hypothesis that the visual environment of complexity and variety is closely correlated with the parallax effect and monotonous or non-parallax environment, and parallax effect on close view more bigger than the distant view. Factors covering the spatial image of parallax landscape were found to be seven and Total values were 60.35 %. The most important factors determining the parallax effect were Factors I 'depth of space' and VI 'expectation of space and interest'. An outstanding view must be handled properly to be preserved or accentuated. In this sense, the parallax spatial beauty with tree could be improved through the visual aspects of plan arrangements and the progressive realization appeared to be one effective design technique for landscape planning and design.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.1
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• pp.23-30
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• 2021

Purpose: The aim of this study was to investigate effect of zirconia on osseointegration and Surface appearance by surface treatments using various acid solution. Materials and Methods: The prepared zirconia disks were treated with hydrofluoric acid solution and photo-assisted etching under various condition. The surface was analyzed by SEM and the surface roughness was analyzed by using surface profiler. The osteogenic effect of MC3T3-E1 cells was assessed via fluorescent staining observation and reverse transcriptase-polymerase chain reaction (RT-PCR). Results: Various roughness were obtained according to the surface treatment method. The surface roughness increased in the group treated with hydrofluoric acid solution, but that had week network structure. In the method using photo-assisted etching, the surface roughness increased in micro units. Cell reaction showed better results in the photo-assisted etching group than in the hydrofluoric acid-treated group (P < 0.05). And it showed even osteoblastic cell distribution in photo-assisted etching group. Conclusion: As a result, the photo-assisted etching method is more effective than the simple acid solution treatment for zirconia treatment for osseointegration.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.178-178
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• 2016

Every display is equipped with a cover glass to protect the underneath displaying devices from mechanical and environmental impact during its use. The strengthened glass such as Gorilla glass.$^{TM}$ has been exclusively adopted as a cover glass in many displays. Conventionally, the strengthened glass has been manufactured via ion-exchange process in wet salt bath at high temperature of around $500^{\circ}C$ for hours of treatment time. During ion-exchange process, Na ions with smaller diameter are substituted with larger-diameter K ions, resulting in high compressive stress in near-surface region and making the treated glass very resistant to scratch or impact during its use. In this study, PIIID (plasma immersion ion implantation and deposition) technique was used to implant metal ions into the glass surface for strengthening. In addition, due to the plasmonic effect of the implanted metal ions, the metal-ion implanted glass samples got colored. To implant metal ions, plasma immersion ion implantation technique combined with HiPIMS method was adopted. The HiPIMS pulse voltage of up to 1.4 kV was applied to the 3" magnetron sputtering targets (Cu, Ag, Au, Al). At the same time, the sample stage with glass samples was synchronously pulse-biased via -50 kV high voltage pulse modulator. The frequency and pulse width of 100 Hz and 15 usec, respectively, were used during metal ion implantation. In addition, nitrogen ions were implanted to study the strengthening effect of gas ion implantation. The mechanical and optical properties of implanted glass samples were investigated using micro-hardness tester and UV-Vis spectrometer. The implanted ion distribution and the chemical states along depth was studied with XPS (X-ray photo-electron spectroscopy). A cross-sectional TEM study was also conducted to investigate the nature of implanted metal ions. The ion-implanted glass samples showed increased hardness of ~1.5 times at short implantation times. However, with increasing the implantation time, the surface hardness was decreased due to the accumulation of implantation damage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.3
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• pp.15-30
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• 2004

In this paper, an analytical modeling for the dark and photo-current characteristics of a buried-gate short- channel GaAs MESFET is presented. The presented model shows that the increase of drain current under illumination is largely due to not the increase of photo-conductivity in the neutral region but the narrowing effect of the depletion layer width. The carrier density profile within the neutral region is derived from solving the carrier continuity equation one-dimensionally. In deriving the photo-generated current, we assume that the photo-current is compensated with the thermionic emission current at the gate-channel interface. Moreover, the two-dimensional Poisson's equation is solved by taking into account the drain-induced longitudinal field effect. In conclusion, the proposed model seems to provide a reasonable explanation for the dark and photo current characteristics in a unified manner.

• Macromolecular Research
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• v.13 no.6
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• pp.477-482
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• 2005

Photopolymers are attractive materials for holographic 3-D data storage because of their high photosensitivity and large refractive index modulation. We synthesized the six-armed dendrimer for fabricating the new photopolymer. It was prepared using the initiating mixture of hexaarylbiimidazole (HABI), mercapto-benzoxazole (MOBZ), and 2,6-bis(4-diethylaminobenzylidene)cyclopentanone (DEAW), which is sensitive to 514 nm wavelength. The holographic gratings were fabricated successfully in these photopolymer samples by conventional optical interference method. We investigated the effect of dendrimer, either as a binder or as a plasticizer in the cellulose acetate butyrate (CAB), on the diffraction behavior. The addition of only 1 wt$\%$ of dendrimer-I into the CAB significantly increased the diffraction efficiency. The sample doped with dendrimer showed around 80-83$\%$ of the diffraction efficiency.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.602-604
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• 2004

NPB surface morphologies deposited on different temperature substrates were investigated using atomic force microscopy(AFM). It has been found that the NPB morphology turned from island morphology at high temperature(100$^{\circ}C$) to grain morphology at room temperature. To characterize the effect of NPB surface morphology, the devices with the structure of Glass/ITO/NPB/$Alq_3$/Al were fabricated using NPB films deposited at different substrate temperature and their performances were compared.