• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.421.1-421.1
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• 2016

We studied indium-doped zinc oxide (IZO) film grown by atomic layer deposition (ALD) as transparent conductive oxide (TCO). A variety of TCO layer, such as ZnO:Al (AZO), InSnO2(ITO), Zn (O,S) etc, has been grown by various method, such as ALD, chemical vapor deposition (CVD), sputtering, laser ablation, sol-gel technique, etc. Among many deposition methods, ALD has various advantages such as uniformity of film thickness, film composition, conformality, and low temperature deposition, as compared with other techniques. In this study, we deposited indium-doped zinc oxide thin films using diethyl[bis(trimethylsilyl)amido]indium [Et2InN(TMS)2] as indium precursor, DEZn as zinc precursor and H2O as oxidant for ALD and investigated the optical and electrical properties of IZO films. As an alternative, this liquid In precursor would has several advantages in indium oxide thin-film processes by ALD, especially for low resistance indium oxide thin film and high deposition rate as compared to InCp, InCl3, TMIn precursors etc. We found out that Indium oxide films grown by Et2InN(TMS)2 and H2O precursor show ALD growth mode and ALD growth window. We also found out the different growth rate of Indium oxide as the substrate and investigated the effect of the substrate on Indium oxide growth.

• 한국정밀공학회지
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• 제30권4호
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• pp.421-426
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• 2013

Nowadays in building construction field, workers become aged and avoid dirty, difficult, and dangerous work. Above all, a person who is in charge of beam assembling work in high and narrow space just relies on safety belt. So these workers should be highly trained. This paper deals with a new locomotion robot that can take this in charge, which will be able to provide less labor costs, less time to build a building and safer environments for workers. The geometric features of steel structure in building construction were carefully analyzed and developed a locomotion mechanism optimized to it. The robot was designed to be rugged, strong, and fast rather than having excessive mobility. Feasibility of the developed robot was verified through experiments.

• 한국표면공학회지
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• 제51권6호
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• pp.421-429
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• 2018

In this study, various electrochemical experiments were carried out to compare the corrosion characteristics of AA5052-O, AA5083-H321 and AA6061-T6 in seawater. The electrochemical impedance and potentiostatic polarization measurements showed that the corrosion resistance is decreased in the order of AA5052-O, AA5083-H321 and AA6061-T6, with AA5052-O being the highest resistant. This is closely associated with the property of passive film formed on three tested Al alloys. Based on the slope of Mott-Schottky plots of an n-type semiconductor, the density of oxygen vacancies in the passive film formed on the alloys was determined. This revealed that the defect density is increased in the order of AA5052-O, AA5083-H321 and AA6061-T6. Considering these facts, it is implied that the addition of Mg, Si, and Cu to the Al alloys can degrade the passivity, which is characterized by a passive film structure containing more defect sites, contributing to the decrease in corrosion resistance in seawater.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.421-422
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• 2010

• 한국환경과학회지
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• 제21권4호
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• pp.421-435
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• 2012

Novel $N_2O_2$ tetradentate ligands, H-3BPD and H-2BPD were synthesized. Hydrochloric acid salts of Br-3BPD, Cl-3BPD, Br-2BPD and Cl-2BPD having Br and Cl substituents at the $para$ position of the phenol hydroxyl group, were synthesized. The ligands were characterized by C. H. N atomic analysis, $^1H$ NMR, $^{13}C$ NMR, UV-visible, and mass spectra. The proton dissociation constants ($logK_n{^H}$) of the phenol hydroxyl group and secondary amine of the synthesized $N_2O_2$ ligands were shown by four step wise values. The orders of the calculated overall proton dissociation constants ($log{\beta}_p$) were Br-3BPD < Cl-3BPD < H-3BPD in case of 3BPD and Br-2BPD < Cl-2BPD < H-2BPD in case of 2BPD respectively. The order agreed well with that of $para$ Hammett substituent constants(${\delta}_p$). The stability constants($logK_{ML}$) of the complexes between the synthesized ligands and transition metal(II) ions agreed with the order of $log{\beta}_p$ of the ligands. The order of the $logK_{ML}$ value of the each transition metal (II) ion was Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II), which agreed well with that of Iriving-Williams series.

• 한국결정학회지
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• 제2권1호
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• pp.12-16
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• 1991

p-dimethylaminobenzaldehyde 4-(p-ethoxyphenyl) thiosemicarbazone, C18H22N4OS의, 단위포상수는 단사정계 a=11.802(2), b=31.962(2), c=9.829(2)A, β=100.12(1)˚, V=3694.8A3이며 F(000)=1472, Mr=342.47, 공간군은 P2₁/c, Z=8, Dx=1.246 Mg m-3, Dm=1.17Mg m-3, μ=0.15mm-1이다. T=294 K에서 Mo Ka(λ=0.71073 A)을 사용하여 최종 R값은 0.0856이다. 비대칭단위내의 두개 분자간의 구조상의 큰차이는 C(9)-N(1)-C(6)-C(7)의 비틀림각이 각각 58.8(8)˚와 1(1)˚인것으로, 각 분자는 길이가 각각 2.613(7)과 2.566(7) A인 N(1)-H(10)'N(3) 분자내 수고결합을 하고 있으며 각 분자는 N(2)원자를 정점으로 하여 V-모양을 하고 있다. 독립적인 두 분자는 두개의 분자간 수소 결합 N(2)-H(11)'S'=3.367(5) A과 N(2')-H(11')'S=3.421(4)A으로 연결되어 이중체(dimer)를 형성하고 있으며 그 이중체들은 van der Waals력으로 결합되어 있다.

• 한국과학예술포럼
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• 제20권
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• pp.421-428
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• 2015

전기/하이브리드 자동차, 도금용 정루기 등에 들어가는 전력변환장치는 SCR, MOSFET, IGBT와 같은 스위칭 소자가 필수적으로 사용되며 이를 구동하기 위해서는 Gate Driver가 역시 필수적으로 사용된다. 본 논문에서는 대용량 전력변환장치에 사용되는 스위칭소자 SCR/IGBT를 구동하는데 필요한 Gate Driver를 제안한다. 제안된 Gate Driver는 4개의 BJT를 이용한 H-Bridge를 포함하며, 이는 입력된 DC 전력을 AC로 변환하여 Transformer를 통하여 Isolate 된 전원을 생성한다. 또한 Gate 제어 신호는 입력 전원과 Isolated된 전원이 연결된 Photo Coupler를 통해 Isolate된 제어 신호로 변환하여 실제 SCR/IGBT를 구동한다. 본 논문에서는 Simulation을 통해서 설계된 555 Timer를 통한 H-Bridge 동작을 검증하며 시제품을 제작하여 27V 50,000A 급의 도금용 정류기를 구동시켜 파형을 확인함으로써 제안된 Gate Driver의 타당성을 검증한다.

• 미생물학회지
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• 제32권3호
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• pp.232-237
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• 1994

Glutaryl 7-aminodeacetoxycephalosporanic acid(GL-7-ADCA)로부터 7-aminodeacetoxycephalosporanic acid(7-ADCA)를 생성하는 GL-7-ADCA acylase생산균을 자연계에서 폭넓게 검색하여 한균주를 선정하고 분리균의 형태 및 생리적 성질들을 조사하여 Alcaligenes sp.로 동정하였다. 분리균의 효소생산을 위한 배양조건을 검토한 결과 탄소원으로는 glucose, 질소원으로는 yeast extract, monosodium L-glutamate가 우수하였다. 효소의 작용최적 pH는 8.0이며, pH7.0~pH11.0 번위에서 비교적 안정하였다. 5l jar fermentor에서 배양경과를 조사한 결과 효소이 활성은 $37^{\circ}C$, 교반속도 300rpm, 통기량 1vvm 조건에서 20시간~30시간 배양시 가장 높았다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.421-422
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• 2013

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.421-422
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• 2009