• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.81-84
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• 2002

This paper presents the real-time PCB(Printed circuit board) inspection system that can detect thin open/short error using the line scan camera. After a overall introduction of our system, the outline of our inspection methods are described. The goal of our inspection system is the real time and detailed inspection using the line scan camera. To perform inspection processing in real-time, we utilize double buffering structure. In order to solve the problem of unexpectable pixels of PCB, we propose melting process which eliminates unexpectable pixels of PCB. The design and development of our prototype of PCB ins- pection system is discussed and test results are presented to show the effectiveness of the developed inspection algorithm.

• 한국자기공명학회논문지
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• 제8권2호
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• pp.96-107
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• 2004

We prepared two oligonucleotides containing same base pairing, but different base sequence in the middle region, d(CGAATTCG) and d(CGTATACG). NMR and UV absorbance data represented that such variation in base sequence could cause a significant difference in melting temperature and dynamics between d(CGAATTCG)$_2$ and d(CGTATACG)$_2$ duplexes, which are regarded to be associated with the stacked structure and the width of the minor groove of them. The latter showed poor stability compared to the former, because of poor stacking of bases. And berenil could bind to the minor groove of d(CGAATTCG)$_2$ which is relatively narrow, more strongly than d(CGTATACG)$_2$ and this gave rise to large improvement in thermal stability of the d(CGAATTCG)$_2$ duplex, compared to d(CGTATACG)$_2$.

• Journal of Pharmaceutical Investigation
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• 제36권3호
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• pp.169-174
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• 2006

The aim of this work was to prepare tenoxicam-ethanolamine salt with improved physicochemical properties for transdermal application. Tenoxicam-ethanolamine salt was prepared in methylene chloride and its physicochemical properties were investigated by DSC and FT-lR. The broad peak of tenoxicam around 3600-3200 $cm^-1$ was shifted to lower wavenumber and more broadened. The characteristic endothermic melting peak of tenoxicam appeared at $223^{\circ}C$. The melting peak of tenoxicam-ethanolamine salt was shifted to $159^{\circ}C$. In contrast to relatively small difference in the partition coefficients of tenoxicam and the tenoxicam-ethanolamine salt, large difference in aqueous solubility was observed. $Crovol^{\circledR}$ PK4O (PEG-12 palm kernel glycerides) provided the highest skin flux for both compounds. The order of the enhancing effect of the various vehicles tested was similar for tenoxicam and tenoxicam-ethanolamine salt, which indicated that their enhancing mechanism for tenoxicam and tenoxicam-ethanolamine salt is similar. Tenoxicam-ethanolamine salt had a higher skin flux than tenoxicam by 1.2- to 31.7-fold, depending on the vehicles used. It is suggested that the vehicles with medium HLB value, 1 double bond, and lower ethylene oxide chain length have a better ability to modify the permeability of the stratum corneum and to promote the effective penetration of tenoxicam and tenoxicam-ethanolamine salt.

• 마이크로전자및패키징학회지
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• 제16권4호
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• pp.23-28
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• 2009

Si 기판의 캐비티 형성이 불필요한 웨이퍼-레벨 MEMS capping 공정을 연구하였다. 4인치 Si 웨이퍼에 Ni 캡을 전기도금으로 형성하고 Ni 캡 rim을 Si 하부기판의 Cu rim에 에폭시 본딩한 후, SnBi debonding 층을 이용하여 상부기판을 Ni 캡 구조물로부터 debonding 하였다. 진공증착법으로 형성한 SnBi debonding 층은 Bi와 Sn 사이의 심한 증기압 차이에 의해 Bi/Sn의 2층 구조로 이루어져 있었다. SnBi 증착 층을 $150^{\circ}C$에서 15초 이상 유지시에는 Sn과 Bi 사이의 상호 확산에 의해 eutectic 상과 Bi-rich $\beta$상으로 이루어진 SnBi 합금이 형성되었다. $150^{\circ}C$에서 유지시 SnBi의 용융에 의해 Si 기판과 Ni 캡 구조물 사이의 debonding이 가능하였다.

• 한국수정란이식학회지
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• 제25권2호
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• pp.111-116
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• 2010

Sperm chromatin integrity is essential for successful fertilization and development of an embryo. Reported here is a quantification of DNA fragments which is intimately associated with reproductive potential to provide one of criteria for sperm chromatin integrity. Three sperm populations were considered: CONTROL (no treatment), UV irradiation (48mW/$cm^2$, 1h) and $H_2O_2$ (oxidative stress induced by hydrogen peroxide, 10 mM, 50 mM and 100 mM). DNA fragments in boar sperm were evaluated by using ligation-mediated quantitative real-time polymerase chain reaction (LM-qPCR) assay, which relies on real-time qPCR to provide a measure of blunt 5' phosphorylated double strand breaks in genomic DNA. The results in agarose gel electrophoresis showed no significant DNA fragmentation and no dose-dependent response to $H_2O_2$. However, the remarkable difference in shape and position was observed in melting curve of LM-qPCR. This result supported that the melting curve analysis of LM-qPCR presented here, could be more sensitive and accurate than previous DNA fragmentation assay method.

• 한국진공학회지
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• 제9권3호
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• pp.263-266
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• 2000

본 논문에서는 낮은 구동 전압에서 동작하고 안정된 on/off 상태를 갖는 Al/$TiO_2-SiO_2$/Mo 형태의 안티퓨즈를 제작하였다. 하부전극으로 사용된 Mo 금속은 표면상태가 부드럽고 녹는점이 높은 매우 안정된 금속으로, 표면 위에 제조된 $SiO_2$ 특성을 매우 안정되게 유지시켰다. 또한 $TiO_2$절연막을 $SiO_2$절연막 위에 복층 구조로 증착하여, Ti 금속의 침투로 인한 $SiO_2$ 절연막의 약화로 동일 두께(100 $\AA$)의 $SiO_2$, 단일막에 비하여 향상된 절연파괴 전압을 얻을 수 있었다. $TiO_2-SiO_2$ 이중절연막을 사용하여 적정 절연파괴전압 및 ON-저항을 구현하였으며, 두께가 두꺼워짐으로 인해 바닥금속의 거칠기의 영향을 최소화시킬 수 있었다. 이중 절연막의 두께는 250 $\AA$이고 프로그래밍 전압은 9.0 V이고 약 65 $\Omega$의 on 저항을 얻을 수 있었다.

• 한국결정성장학회지
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• 제34권2호
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• pp.61-65
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• 2024

HVPE(Hydride vapor phase epitaxy) 공법은 기체상의 원료를 사용하여 박막 또는 단결정을 제조하는 공법이다. 화학적 기상증착법의 원리를 적용하여 난용융성 또는 고융점의 물질의 단결정을 성장할 수 있는 공법으로서, 질화갈륨(GaN) 단결정을 얻을 수 있는 공법 중 하나이다. 최근 동 공법을 이용하여 질화알루미늄(AlN) 단결정을 성장하고자 하는 연구가 많이 수행되어져 왔으나, 아직은 좋은 결과를 얻지 못하고 있다. 본 연구에서는 AlN 단결정을 HVPE 공법으로 성장하고자 하였다. 성장 공정에서 질소를 운송가스(Carrior gas)로 사용하였으며, 질소(N2)의 양의 변화에 따른 성장 결과를 고찰하여 보았다. 질소의 양이 증가함에 따른 성장 결정의 변화 양상을 확인할 수 있었다. 성장된 AlN 단결정의 형상을 광학 현미경을 사용하여 관찰하였고, 이중결정 X선 회절 분석(DCXRD, Double crystal X-ray diffractometry)을 이용하여, AlN 결정의 생성을 확인함과 동시에 성장된 단결정의 결정성도 알아보았다.

• 한국표면공학회지
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• 제33권2호
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• pp.93-100
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• 2000

Effects of Ti content and Ti underlayer on the pitting behavior of TiN coated AISI 304 stainless steel have been studied. The stainless steel containing 0.1~1.0wt% Ti were melted with a vacuum melting furnace and heat treated at $1050^{\circ}C$ for 1hr for solutionization. The specimen were coated with l$\mu\textrm{m}$ and 2$\mu\textrm{m}$ thickness of Ti and TiN by E-beam PVD method. The microstructure and phase analysis were conducted by using XRD, XPS and SEM with these specimen. XRD patterns shows that in TiN single-layer only the TiN (111) Peak is major and the other peaks are very weak, but in Ti/TiN double-layer TiN (220) and TiN (200) peaks are developed. It is observed that the surface of coating is covered with titanium oxide (TiO$_2$) and titanium oxynitride ($TiO_2$N) as well as TiN. Corrosion potential on the anodic polarization curve measured in HCl solution increase in proportion to the Ti content of substrate and by a presence of the Ti underlayer, whereas corrosion and passivation current densities are not affected by either of them. The number and size of pits decrease with increasing Ti content and a presence of the coated Ti film as underlayer in the TiN coated stainless steel.

• 한국분말재료학회지
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• 제5권2호
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• pp.89-97
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• 1998

Sintering behavior of nanostructured(NS) W-Cu powders prepared by mechanical alloying (MA) was investigated as a function of sintering temperature. MA NS W-2owt%Cu and W-3owt%Cu composite powders with the crystal size of 20-30 nm were annealed at 90$0^{\circ}C$, and thermal characteristics of those powders were investigated by DSC. Sintering behavior of MA NS W-Cu composite powders was investigated during the solid-state sintering and the Cu-liquid phase sintering. The new nanosintering phenonenon of MA W-Cu powders at solid-state sintering temperature was suggested to explain the W-grain growth in the inside of MA powders. The sintering densification of MA NS W-Cu powders was enhanced at Cu melting temperature by arrangement of MA powders, i.e., the first rearrangement of MA powders was occurred, and then the rearrangement of W-grains in the sintered parts was also took place during liquid-phase sintering, i.e., the second rearrangement was happened. Due to the double rearrangement process of MA NS W-Cu powders, the high sintered density with more than 96%o was obtained and the fine and high homogeneous state of W and Cu phases was achieved by sintering at 1200 $^{\circ}C$.

• 한국응용과학기술학회지
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• 제16권2호
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• pp.127-133
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• 1999

New electroluminescent materials base on anthracene chromophore, [9.10-bis(${\alpha}$-naph -thylethenyl) anthracene (${\alpha}$-BNA)] were newly synthesized. The anthracene derivatives with bulky substituent possessed high melting point and they gave stable amorphous films through vacuum - sublimation methods. Three types of electroluminescent devices were fabricated with double layer and triple layer structure : ITO/TPD/emission layer/MgAg, ITO/emission layer/ OXD-7 and ITO/ TPD/ emission layer/OXD-7/MgAg, respectively. In three types of devices with the emissive layer of ${\alpha}$-BNA, efficient orange electroluminescence was observed. In the triple layer device whit a emitting layer of 20 nm thickness , maximum luminance was about 10000 cd/ $m^2$ at an applied voltage of 10v and maximum external quantum efficiency was 1.0%.