• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.68-71
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• 2004

본 연구는 싱크로트론 방사광의 단색광 (monobeam)을 이용한 영상을 획득하였다. 영상센서로서 CMOS를 사용하였으며 센서 앞단에는 형광체 (phosphor)를 이용하여 방사광에 대한 빛의 신호로서 영상을 획득하였다. 사용된 싱크로트론 방사광의 beam size는 $5mm{\times}2mm$ 이며 ion chamber를 통한 beam intensity 는 $10{\times}10^{-7}$이다. 형광체는 각각 ZnS(Cu:Al), ZnS(Ag,Al), $BiTiO_3$, $Y_2O_2S(Tb)$로서 4가지를 사용하였으며 여기에 사용된 형광체는 기계식 스크린 프린팅 (Screen Printing) 방식으로 직접 제조하였다. 두께는 모두 동일하게 $10{\mu}m$이며 각각에 대한 PL(Photoluminescence)을 측정하여 분석하였다. object로는 물고기와 20linepair를 사용하였으며 CMOS센서를 이용하여 각각의 phosphor에 대하여 영상을 획득하였다. 영상의 평가는 20line pair 영상의 MTF를 이용하였다. 각각의 형광체에 대한 MTF는 5 lp/mm 에서는 0.5650, 0.2150, 0.7890, 0.3840 이며 10 lp/mm 은 0.4500, 0.0900, 0.2510, 0.1500이고 15 lp/mm 는 0.1900, 0.0300, 0.1430, 0.0500이며 마지막으로 20 lp/mm 은 0.0810, 0.004, 0.0500, 0.0320의 MTF 값을 나타내었다. $10{\mu}m$ 두께에 대하여 ZnS(Cu:Al)이 가장 좋은 MTF의 값을 나타내었다.

• 한국해양환경ㆍ에너지학회지
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• 제13권1호
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• pp.43-46
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• 2010

중소형 폐 선박으로부터 배출되는 FRP를 재활용하기 위한 방법으로 층상으로 배열된 로빙층과 매트층을 분리하는 것은 에너지 면에서나 환경적인 면에서 많은 장점을 가지고 있다. 비록 로빙층과 매트층은 모두 유리섬유로 이루어져있으나 수지함유량의 차이와 유리섬유의 조직형태의 차이로 인하여 재활용 용도는 매우 달라지고 있다. 그러나 로빙층은 매트층에 비해 얇은 두께로 존재한다는 이유로 인해 로빙층을 FRP에서 분리할 때 기계가 자동적으로 층간의 차이를 인식하기는 매우 어렵다. 따라서 이 추출과정에서 많은 로빙층의 손실과 공정의 난이도에 의한 처리시간 지연 등의 문제가 발생한다. 본 연구에서는 유리의 구성비가 다른 두 층의 화학적 성질의 차를 이용하여 광학적으로 층간 인식이 가능한 방법을 모색하였다. FRP에 대해 유리의 $SiO_2$와 반응하는 플루오르산(HF) 용액으로 처리한 후 수용성 염료를 도포한 경우 두 층간의 차별화가 확연하게 일어났다. 본 연구는 이 결과를 이용하여 폐 FRP의 면포분리 공정의 효율성을 극대화 할 수 있는 시스템을 개발 하였다.

• 센서학회지
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• 제28권1호
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• pp.41-46
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• 2019

In order to develop novel thermal imaging materials for microbolometer applications, $[(Ni_{0.3}Mn_{0.7})_{1-x}Cu_x]_3O_4$ ($0.18{\leq}x{\leq}0.26$) thin films were fabricated using metal-organic decomposition. Effects of Cu content on the electrical properties of the annealed films were investigated. Spinel thin films with a thickness of approximately 100 nm were obtained from the $[(Ni_{0.3}Mn_{0.7})_{1-x}Cu_x]_3O_4$ films annealed at $380^{\circ}C$ for five hours. The resistivity (${\rho}$) of the annealed films was analyzed with respect to the small polaron hopping model. Based on the $Mn^{3+}/Mn^{4+}$ ratio values obtained through x-ray photoelectron spectroscopy analysis, the hopping mechanism between $Mn^{3+}$ and $Mn^{4+}$ cations discussed in the proposed study. The effects of $Cu^+$ and $Cu^{2+}$ cations on the hopping mechanism is also discussed. Obtained results indicate that $[(Ni_{0.3}Mn_{0.7})_{1-x}Cu_x]_3O_4$ thin films with low temperature annealing and superior electrical properties (${\rho}{\leq}54.83{\Omega}{\cdot}cm$, temperature coefficient of resistance > -2.62%/K) can be effectively employed in applications involving complementary metal-oxide semiconductor (CMOS) integrated microbolometer devices.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.169-173
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• 2007

During laser irradiation, mechanically deformed cartilage undergoes a temperature dependent phase transformation resulting in accelerated stress relaxation. Clinically, laser-assisted cartilage reshaping may be used to recreate the underlying cartilaginous framework in structures such as ear, larynx, trachea, and nose. Therefore, research and identification of the biophysical transformations in cartilage accompanying laser heating are valuable to identify critical laser dosimetry and phase transformation of cartilage for many clinical applications. quasi-elastic light scattering was investigated using Ho : YAG laser $(\lambda=2.12{\mu}m\;;\;t_p\sim450{\mu}s)$ and Nd:YAG Laser $(\lambda=1.32{\mu}m\;;\;t_p\sim700{\mu}s)$ for heating sources and He : Ne $(\lambda=632.8nm)$ laser, high-power diode pumped laser $(\lambda=532nm)$, and Ti : $Al_2O_3$ femtosecond laser $(\lambda=850nm)$ for light scattering sources. A spectrometer and infrared radiometric sensor were used to monitor the backscattered light spectrum and transient temperature changes from cartilage following laser irradiation. Analysis of the optical, thermal, and quasi-elastic light scattering properties may indicate internal dynamics of proteoglycan movement within the cartilage framework during laser irradiation.

• 센서학회지
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• 제16권2호
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• pp.97-103
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• 2007

Crystallized carbon nitride film that has many stable physical and/or chemical properties has been expected potentially by a new electrical material. However, one of the most significant problems degrading the quality of carbon nitride films is an existence of N-H and C-H bonds from the deposition environment. The possibility of these reactions with hydroxyl group in carbon nitride films, caused by a hydrogen attack, was suggested and proved in our previous reports that this undesired effect could be applied for fabricating micro-humidity sensors. In this study, MIS capacitor and MIM capacitor with $5{\mu}m{\times}5{\mu}m$ meshes were fabricated. As an insulator, carbon nitride film was deposited on a $Si_{3}N_{4}/SiO_{2}/Si$ substrate using reactive magnetron sputtering system, and its dielectric constant, C-V characteristics and humidity sensing properties were investigated. The fabricated humidity sensors showed a linearity in the humidity range of 0 %RH to 80 %RH. These results reveal that MIS and MIM $CN_{X}$ capacitive humidity sensors can be used for Si based micro-humidity sensors.

• Journal of Biosystems Engineering
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• 제28권2호
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• pp.167-172
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• 2003

This study was performed to fabricate a batch-type SPR biosensing system using a thiolated E. coli antibody coupling, and to explore the feasibility of real-time detection of E. coii in a stagnant sample solution. In advance. “O” and “K” antigenic serotype E. coli antibodies were thiolated with sulfo-LC-SPDP and dithiothreitol, and immobilized by chemisorption in the gold surface of compact SPR sensors. When the SPR biosensor immobilized with E. coli antibody monitored a E. coli solution, it took 3 to 5 min to stabilize. The SPR biosensing system developed in this study was able to detect E. coli in the range above 10$^4$ CFU/mL at the 0.05 significant level. Also, the SPR biosensor had possibility to significantly detect E. coli in the range of 10$^2$ to 10$^4$ CFU/mL in E. coli solutions. Meanwhile, when the SPR biosensor immobilized with 5. coli antibody was cleaned with NaOH solutions, its ability to detect E. coli largely decreased due to wash-out of the immobilized antibody. In order to reuse the SPR sensor, it should be antibody-immobilized newly.

• 전기학회논문지
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• 제60권9호
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• pp.1770-1776
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• 2011

In this study, a new method that can estimate ICG data from a subject's both hands to measure Cardiac Output under convenient sensor environment. With this aim, a grip-type electrode was implemented to measure ICG. To improve the accuracy of measurement, the regression equation was extracted using multiple bio-parameters and our result was compared with the thoracic ICG equipment(Physio Flow$^{(R)}$, PF104D, Manatec Biomedical, France), which is being used in clinics. The subjects consist of 26 men and 4 women(age in $22.0{\pm}3.32$). They are no cardiac disease. Parameters available for regression model were used gender, BMI, MBP, LVET, dZ/dt(max), distance between the measured electrodes, body impedance, and PTT. As a result of analyzing the ICG measurement value on thorax and both hands, the correlation with stroke volume, heart rate, and cardiac output was $R^2$=0.853, $R^2$=0.958 and $R^2$=0.899, respectively.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.40-64
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• 2005

Much biochemical information on peroxiredoxins (Prxs) has been reported but a genuine physiological function for these proteins has not been established. We show here that two cytosolic yeast Prxs, cPrxI and II, exist in a variety of forms that differ in their structure and molecular weight (MW) and that they can act both as a peroxidase and as a molecular chaperone. The peroxidase function predominates in the lower MW proteins, whereas the chaperone function is more significant in the higher MW complexes. Oxidative stress and heat shock exposure of yeasts causesthe protein structures of cPrxI and II to shift from low MW species to high MW complexes. This triggers a peroxidase-to-chaperone functional switch. These in vivo changes are primarily guided by the active peroxidase site residue, $Cys^{47}$, which serves as an efficient $'H_2O_2-sensor'$ in the cells. The chaperone function of the proteins enhances yeast resistance to heat shock.

• 한국재료학회지
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• 제13권2호
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• pp.106-110
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• 2003

Nano-sized powders of Indium Tin Oxide(ITO) were synthesized by a coprecipitation method. In order to investigate the gas sensing characteristics in the nanocrystalline ITO thick films with various particle sizes, ITO powders with the average particle diameter of 15, 30, and 70 nm respectively were synthesized. And the sensitivity of ITO thick films was measured upon exposure to a target gas($C_2$$H_{5}$ /OH) and some other Volatile Organic Compounds(VOCs), such as, toluene, methanol, benzene, chloroform. As a result, ITO thick films had high sensitivity for ethanol and higher sensitivity with smaller particle size.

• 한국의류학회지
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• 제21권4호
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• pp.750-756
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• 1997

The purpose of the study was to investigate a transmittance rate of UVB (Ultraviolet B) through summer fabrics and a protection rate of summer fabric from UVB. The subjects were randomly selected 159 fabrics from Korean common summer fabrics. The protection rates of 159 fabrics from UVB were measured by UVB lamp and UVB sensor, and 14 fabrics among these fabrics were selected for an assay of MTT(3-(4, 5-dimethylthiazol-2-yl) -2, 5 -diphenyltetrazolium). The protection rate of fabrics from cell toxicity of UVB was measured by investigating the difference of the amount of cell toxic substance on between fabrics covered with and without HeLa cell The average protection rate of 159 fabrics from UVB was 95.08%. As result findings, three negative correlations were found between: 1) the transmittance rate of UVB and the amount of MTT on fabrics (y=0.0373+0.O0518 x, r=-0.9323, p<0.001); 2) the air permeability of fabrics and the amount of MTT (r: -0.79, p< 0.01); 3) the air permeability of fabrics and the protection rate of fabrics from UVB (r=0.89, p<0.01). However, there was no effect of thickness of fabrics on the protection rate from UVB and the amount of MTT.