• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.185-185
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• 2009

The aligned liquid crystals (LCs) display on SiNx thin films using ion-beam (IB) irradiation was studied with controllability ofpretilt angle depending on incident energies of the IB. Plasma-enhanced chemical vapor deposition (PECVD) was used to orient the LCs on SiNx alignment films. The LCs alignment property for the SiNx thin films were observed to verify the practical application potential (figure1). A good LCs alignment of vertical alignment LCs cells on SiNx thin film surfaces irradiated with incident IB energy of 1800eV was achieved. Also, a good LC alignment by the IB irradiation on the SiNx thin film surface was observed at an annealing temperature of $180^{\circ}C$. However, the alignment defects of the nematic liquid crystal was observed at an annealing temperature above $230^{\circ}C$. The atomic force microscopy (AFM) images of LCs on SiNx thin film surfaces irradiated with IB energy was used for the surface analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.184-184
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• 2009

This paper introduces the characteristics of SnO2 inorganic film deposited by radio-frequency magnetron sputtering as an alternative alignment layer for liquid crystal display (LCD) applications. The pretilt angle of the SnO2 layer was shown to be a function of the ion beam(IB) incident angle, a planer alignment of nematic liquid crystal was achieved. The about $1.8^{\circ}$ of stable pretilt angle was achieved at the range from 1500 ~ 2500eV of incident energy. To characterize the film shows atomic force microscopy (AFM) on the IB irradiated SnO2 surfaceand the X-ray phtoelectron spectroscopy analysis showed that the liquid crystal(LC) alignment on the IB irradiated $SnO_2$ surface was due to the reformation of Sn-O bonds. Also, Figure 1 shows that The alignment capability of the IB irradiated SnO2 layers is maintained until annealing temperature of $200^{\circ}C$. Comparable electro-optical characteristics to rubbed polyimide were also achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.158-158
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• 2009

This paper focuses on improving organic thin film transistor (OTFT) characteristics by controlling the self-organization of pentacene molecules with an alignable high-dielectric-constant film. The process, based on the growth of pentacene film through high-vacuum sublimation, is a method of self-organization using ion-beam (IB) bombardment of the $HfO_2/Al_2O_3$ surface used as the gate dielectric layer. X-ray photoelectron spectroscopy indicates that the IB raises the rate of the structural anisotropy of the $HfO_2/Al_2O_3$film, and X-ray diffraction patterns show the possibility of increasing the anisotropy to create the self-organization of pentacene molecules in the first polarized monolayer. An effective mobility of $2.3{\times}10^{-3}cm^2V^{-1}s^{-1}$ was achieved, which is significantly different from that of pentacene films that are not aligned. The proposed OTFT devices with an ultrathin $HfO_2$ structure as the gate dielectric layer were operated at a gate voltage lower than 5 V.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.1
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• pp.25-33
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• 1998

An experimental study has been carried out to obtain optimal conditions for turbulent mixing of two fluid streams at various angle branches by a flow visualization method. The main purpose of this study is the utilization of flow visualization method as a fast and efficient way to find the optimal mixing conditions when several flow control parameters are superimposed. It is verified that the optimal conditions estimated by flow visualization method have good agreement with the concentration field measurements. The results demonstrate that the diameter ratio is mainly attributed to the mixing phenomena than the branch pipe angle and the Reynolds number. The most striking fact is that there exists the best diameter ratio, d/D.ident. O.17, which requires the minimum momentum ratio in the range of the present experiment. The velocity ratio for the optimal mixing condition has a value within 2 to 16 according to the different flow parameters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.116-116
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• 2009

This paper focuses on improving organic thin film transistor (OTFT) characteristics by controlling the self-organization of pentacene molecules with an alignable high-dielectric-constant film. The process, based on the growth of pentacene film through high-vacuum sublimation, is a method of self-organization using ion-beam (IB) bombardment of the $HfO_2/Al_2O_3$ surface used as the gate dielectric layer. X-ray photoelectron spectroscopy indicates that the IB raises the rate of the structural anisotropy of the $HfO_2/Al_2O_3$ film, and X-ray diffraction patterns show the possibility of increasing the anisotropy to create the self-organization of pentacene molecules in the first polarized monolayer.

• Journal of Nutrition and Health
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• v.37 no.9
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• pp.780-785
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• 2004

Recently many investigators have initiated searches for immunomodulating substances from natural food sources. Ginger (Zingiber officinale Roscoe) has been used as a raw material in many traditional preparations since the ancient time. This study was performed to investigate the immunomodulative effects of Zingiber officinale Roscoe in mice, using ex vivo experiments. In order to elucidate the immunomodulative effects of Ginger, water extracts of the plant were orally administrated into mice, and isolated splenocytes and macrophages were used as experimental model. In order to identify its ex vivo effect six to seven week old Balb/c mice were fed ad libitum on a chow diet and water extracts of ginger were orally administrated every other day for two weeks at two different concentrations (50 and 500 mg/kg b.w.). After preparing the single cell suspension, the proliferation of splenocytes was determined by MTT assay. The result of ex vivo study showed that the highest proliferation of splenocytes and macrophage activatation was seen in the mice orally administrated at the concentration of 500 mg/kg b. w. of ginger water extracts. In conclusion, this study suggests that ginger extracts nay enhance the immune function by regulating the splenocyte proliferation and cytokine prodution capacity by activated macrophages in mice.

• Biomolecules & Therapeutics
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• v.9 no.1
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• pp.40-45
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• 2001

The activity of taurine transporter is affected by various extracellular stimuli such as ion, hormone and stress. To assess effects of steroid hormones antral cyclosporin A (CsA) on the taurine transporter activity, murine monocytic RAW264.7 cell line was stimulated with dexamethasone (DM), triamcinolone (TA), cortisone (CS), hydrocortisone (HCS), prednisone (PSN), prednisolone (PSL) and methylprednisolone (MPSL) in the presence of 12-0-tetradecanoylphorbol-13-acetate(TPA). Treatment of TPA on the cell line led to significant reduction of taurine transporter activity. However, in case of stimulation of the cells with steroid hormones in the presence of TPA, all of them recovered TPA-induced reduction of the taurine transporter activity. Treatment of the cells with CsA led to significant reduction of the taurine transporter activity. Ionomycin (IM) recovered the reduced taurine transporter activity by CsA, but failed in the presence of EDTA, a calcium chelating agent. These results showed that glucocorticoid hormone recovered TPA-induced reduction of taurine transporter activity and that IM recovered CsA-induced reduction of the transporter activity by increasing intracellular free $Ca^{++}$ concentration.n.

• Development and Reproduction
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• v.4 no.1
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• pp.13-17
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• 2000

Follicle stimulating hormone (FSH) stimulates follicle growth, and inhibits the follicle atresia in the immature rodent ovaries. The present study was carried out to know the histological changes of ovarian follicles after FSH treatment in the prepubertal mice. Ten i.u. of recombinant FSH was i.p. injected on 3 weeks old mice. After the treatment, at 1, 2 and 3 days, left ovaries were collected for the histological study. The atretic ratio of preantral follicles increased with time after FSH treatment. However, in the case of antral follicles, there was no significant change in the ratio. The degenerating follicles contained apoptotic granulosa cells, macrophage, and polymorphonuclear leukocytes in the follicular cavity. The present results suggest that follicular degeneration caused by FSH hyperstimulation could be mediated by apoptosis as well as the acute inflammation.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1759-1760
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• 2006

GPS 수신기에서 항법을 수행하기 위해서 신호탐색, 신호추적, 데이터 동기, 데이터 복조, 측정치 생성 및 위치 계산의 과정을 거쳐야 한다. TTFF(Time To First Fix)는 이러한 시간의 합으로 수신기의 성능을 나타내는 중요 평가지수 중의 하나이다. 일반적인 수신기의 TTFF는 80~90초인 것으로 알려져 있으며, 고속으로 운동하는 항체의 경우, 빠른 TTFF를 필요로 하므로 가장 긴 시간이 소비하는 신호탐색 과정의 시간을 줄여야 한다. 본 논문에서는 고속으로 운동하는 항체에서 GPS 신호의 코드 탐색 시간을 줄이기 위하여 다중 상관기 구조를 가지는 수신기를 설계 하고자한다. 설계한 수신기는 수신된 신호의 코드위상을 여러 개의 상관기에서 동시에 탐색하도록 다중 상관기를 구성하여 코드위상 검색에 소요되는 시간을 단축시킨다. 이를 검증하기 위하여 GPS 모의 신호 발생기를 이용하여 실험을 수행하였다. GPS 신호는 IF 데이터 수집 장치로부터 수집된 신호를 이용하며, 실험 수행 결과 다중 상관기를 이용하였을 때 TTFF가 단축되는 것을 확인하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.280-281
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• 2006

We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of a Titanium dioxide ($TiO_2$) thin film by rf magnetron sputtering system for 15min under various rf power. A very low pretilt angle by ion beam exposure on the $TiO_2$ thin film was measured. A good LC alignment by the ion beam alignment method on the $TiO_2$ thin film surface was observed at annealing temperature of $200^{\circ}C$, and the alignment defect of the NLC was observed above annealing temperature of $250^{\circ}C$. Consequently, the low NLC pretilt angle and the good thermal stability of LC alignment by the ion beam alignment method on the $TiO_2$ thin film by sputter method as various rf power condition can be achieved.