• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.38-43
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• 2003

Fabrication process of strain-induced channel waveguides in $LiNbO_3$ was developed using strain-optic effect and compressional strain due to ~1.4 $\mu\textrm{m}$ surface Mo/Pt metal film. Characterization of the channel waveguides revealed a single transverse and depth mode in both TE and TM polarizations. Measurements showed total insertion loss of 6.2 and 7.7 ㏈/cm for TM and TE polarizations. respectively. Electro-optic intensity modulators with 11 mm long electrode length and 21 $\mu\textrm{m}$ electrode gap at $\lambda$ = 1.15 ${\mu}{\textrm}{m}$have been produced in $LiNbO_3$ substrates using strain-induced channel waveguides. Modulation depth of 100% at $\pi$-radian voltage of 16.1V has been demonstrated. Also, 1$\times$2 on/off power splitters at $\lambda$ = 0.63 $\mu\textrm{m}$ have been produced using strain-induced channel waveguides. On/off voltage of $\pm$ 25V has been demonstrated.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1116-1117
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• 2006

Lanthanide tantalite $LnTaO_4$ (Ln= La, Nd, Sm, Dy, Er and Tm) was synthesized by a solid state reaction between mixed powders of $Ln_2O_3$ and $Ta_2O_5$. The single-phase $LnTaO_4$ was prepared by sintering at temperatures of 1423-1673 K in air. The SEM observation showed that the particles were provided with the growth steps and the depeloped facets. The photocatalytic activity for water splitting of $LnTaO_4$ prepared was measured under UV light irradiation. The activity obtained was higher than that previously reported. These results suggested the crystallinity of $LnTaO_4$ photocatalysts correlates closely with the efficiency of water splitting.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.157-161
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• 2016

The purpose of this study is that in measures the acoustic propagate characteristics and temperature sensitivity of ultrasound tissue mimicking phantom(TM phantom). TM phantom manufacture according to the International Electronical Committee(IEC) guidelines for acoustic propagate characteristics of soft tissue. TM phantom was observed to have the image brightness and the image depth penetration decreases changes convergence which was the subject of ultrasound image characteristics in accordance with an external temperature that the change is reduced in temperature below $22^{\circ}C$. This study provide a basis t o create another TM Phantom and TM Phantom has been determined that it is appropriate for use in more than $22^{\circ}C$.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.3
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• pp.41-46
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• 2008

Etching kinetics of $EAGLE^{2000TM}$ LCD glass was investigated using 2.5MHF-xMHCl$(x:0\sim8)$ acid mixtures. It was concluded that the reaction of HF-containing solutions with the glass was the rate-determining step for the dissolution process when considering following observations; the value of the activation energy $35\sim45$ kJ/mol and insensitivity of the dissolution rate to the etching time and the moving velocity of the glass into the solution. The etching rate linearly increased with increasing the HCl concentration in the etchant. It was also observed that the etched surface was as smooth as the original surface by addition of HCl and increase in etching temperature. This is due to the catalytic role of the $H_{3}O^{+]$ ions in the dissolution process.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.393-397
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• 1997

본 연구에서는 손동작(Hand Motion)과 수작업(Manual Task) 분석에 VR환경에서 사용되는 각도 측정 장갑(3-D Glove)을 이용하는 방법을 제안하였다. 본 연구에서 개발된 손동작(Hand Motion)과 수작업(Manual Task)의 분석 시스템은 18-sensor $Cyberglove^{TM}$정 시스템으로부터 측정된 angle data를 기초로 손동작이나 수작업에 대한 totalmuscle moment값과 total muscle excursion값을 구하고, digit와 joint의 moment값을 X,Y.Z방향별고 구하는 기능을 가지고 있다. 시스템의 구성은 : (1) $Cyberglove^{TM}$ System과 분석 시스템의 digital data 처리를 기반으로 하는 손동작의 측정 시스템 ; (2) $Cyberglove^{TM}$ System에서 얻어진 자료를 바탕으로 3차원 공간에서 손동작을 표현할 수 있는 Kinematic Hand Model ; (3) Hand Model과 $Cyberglove^{TM}$ Systme을 기반으로 3차원에서 손동작의 역학적 분석을 할 수 있는 3-D Hand Biomechanical Model ; 등으로 되어있다. 본 시스템은 Telerobotics, Medicine, Virtual Reality 등 다양한 분야에 응용이 가능하며, 수작업에 관련되는 Product Design, Manual Control Device, Computer I/O Device의 설계에도 도움이 될 것으로 기대된다.

• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.430-436
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• 2006

Polarization-independent $Ti:LiNbO_3\;2{\times}2$ optical add/drop multiplexer for the 1550nm wavelength region is fabricated. The device consists of two input waveguides, two polarization beam splitters. two polarization conversion/electrooptic tuning waveguide sections, and two output waveguides. The single mode channel waveguides for both TE and TM polarizations are fabricated on a x-cut $Ti:LiNbO_3$substrate by Ti diffusion. Spectral section is based on phase-matched polarization conversion due to shear strain induced by a thick $SiO_2$ grating overlay film. An applied voltage tunes the device by changing the waveguide birefringence, hence the optical wavelength at which most efficient polarization conversion occurs. Tuning rate of 0.094nm/V with a maximum range of 17nm has been obtained. The nearest side-lobe is about 8.2dB. The FWHM is 3.72nm.

• 한국초전도학회:학술대회논문집
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• v.16
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• pp.94-94
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• 2006

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.305-311
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• 2016

This study investigated the effects of a mixture of fenugreek seeds and Lespedeza cuneata extracts on testosterone synthesis in TM3 cells that were oxidatively stressed with $H_2O_2$. In order to oxidatively stress TM3 cells, the cells were treated with $50{\mu}M$ hydrogen peroxide for 4 hr in serum-free media. Yagwanmun-horopa mixture (YHM) showed neither cytotoxicity nor increment of cell proliferation in the oxidatively stressed TM3 cells in any concentration. When the cells were treated with hydrogen peroxide, testosterone levels decreased, but the testosterone level was returned to that of the control level in the presence of YHM. In order to find out the reasons for the increase of testosterone, the expression of the genes involved in the synthesis or disintegration of testosterone. On the other hand, the levels of $3{\beta}$-HSD4 and 17, 20-desmorase, which are involved in testosterone synthesis, were decreased through the use of hydrogen peroxide and were recovered through YHM treatment. Aromatase and $5{\alpha}$-reductase2, which convert testosterone to estradiol and dihydrotestosterone, respectively, were increased through the use of hydrogen peroxide, and were returned to control level through YHM treatment. These results suggest that YHM does not affect TM3 cell proliferation. However, YHM increases the expression of testosterone-synthesizing enzyme, which was decreased through oxidative stress, and decreases the expression of testosterone- converting enzyme, which was increased through oxidative stress. Therefore, it is reasonable that YHM has strong recovery activity on testosterone to normal level, even in the oxidatively stressed TM3 cells which mimics the andropause state.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.48.2-48.2
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• 2010

The effect of additives as rare-earth in dielectric materials has been studied to meet the development trend in electronics on the miniaturization with increasing the capacitance of MLCCs (multi-layered ceramic capacitors). It was reported that the addition of rare-earth oxides in dielectrics would contribute to enhance dielectric properties and high temperature stability. Especially, dysprosium and thulium are well known to the representative elements functioned as selective substitution in barium titanate with perovskite structure. The effects of these additives on microstructure and electric properties were studied. The 0.8 mol% Dy doped $BaTiO_3$ and the 1.0 mol% Tm doped $BaTiO_3$ had the highest electric properties as optimized composition, respectively. According to the increase of rare-earth contents, the growth of abnormal grains was suppressed and pyrochlore phase was formed in more than solubility limits. Furthermore, the effect of two rare-earth elements co-doped $BaTiO_3$ on the dielectric properties and insulation resistance was investigated with different concentration. The dielectric specimens with $BaTiO_3-Dy_2O_3-Tm2O_3$ system were prepared by design of experiment for improving the electric properties and sintered at $1320^{\circ}C$ for 2h in a reducing atmosphere. The dielectric properties were evaluated from -55 to $125^{\circ}C$ (at $1KHz{\pm}10%$ and $1.0{\pm}0.2V$) and the insulation resistance was examined at 16V for 2 min. The morphology and crystallinity of the specimens were determined by microstructural and phase analysis.

• Journal of Life Science
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• v.28 no.6
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• pp.648-655
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• 2018

Enhancement mechanistic actions of testosterone (TS) productions in mouse Leydig TM3 cells by the eritadenine (EA) and/or the Agaricus blazei mycelial liquid culture extract (ABMLCE). Productions of TS in TM3 cells were investigated in normal and oxidative-stressed culture conditions. In the normal culture condition, TM3 cells grown in a Dulbecco's Modified Eagle's Medium (DMEM) were treated with EA (0~100 ppm) and ABMLCE (10 ppm) + EA (0~50 ppm) for 24 hr, and in the oxidative-stressed culture condition, the cells grown in DMEM containing $50{\mu}M$ $H_2O_2$ to induce oxidative stress for 4 h were treated with the same as those in the normal culture condition. TS content, $3{\beta}$-hydroxysteroid dehydrogenase 2 (HSD3B2) enzyme activity, $5{\alpha}$-reductase 2 ($5{\alpha}-R2$) enzyme activity, and free-radical nitric oxide (NO) content in the culture media were measured using their corresponding assay kits. EA, ABMLCE, and ABMLCE + EA significantly, p<0.05, enhanced TS productions in both cultural conditions, relative to control treatment. The activity of the HSD3B2 enzyme, which is involved in the production of precursors for TS production, was elevated by EA, ABMLCE, and ABMLCE + EA treatments in both culture conditions. The activity of the $5{\alpha}-R2$ enzyme, which converts TS to dihydroxytestosterone (DHT), was not significantly affected in either culture condition by EA, ABMLCE, or ABMLCE + EA treatments. The treatments included reduced NO content. These results indicate that EA, ABMLCE, and EA + ABMLCE treatments elevated TS in TM3 cells via the enhancements of HSD3B2 activity and the reduction of NO production, and also imply that EA and ABMLCE or EA + ABMLCE could be useful materials for the production of TS in humans.