• Title/Summary/Keyword: 구조합성법

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산화아연 나노막대/PDMS 제작기술과 광학적 특성 연구

  • Go, Yeong-Hwan;Lee, Su-Hyeon;Yu, Jae-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.474-474
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    • 2013
  • PDMS는 미세패턴을 위해 소프트 리소그래피 널리 활용되어질 뿐만 아니라, 재질이 투명하고 탄성과 강한 내구성을 갖고 있어 유연한 광학 및 전자소자에 이용될 수 있다. 최근에는, 이러한 PDMS를 서브파장구조(subwavelength grating structure)를 형성하거나 텍스쳐(texture)표면구조를 이용한 효과적인 반사방지막(antireflection coating)기판을 제작하여 태양전지 및 디스플레이 소자의 성능을 발전시키는 연구가 활발히 진행되고 있다. 한편, 수열합성법(hydrothermal method)이나 전기화학증착법(electrodeposition method)으로 비교적 간단한 공정을 통해서 다양한 기판위에 산화아연(ZnO) 나노막대(nanorod)를 수직정렬로 성장시킬 수 있는데, 이러한 구조는 반사방지특성의 유효 굴절률 분포(effective refractive index profile)를 갖고 있기 때문에 LED나 태양전지에 성능을 개선할 수 있다. 이에 본 연구에서는 수열합성법을 통해 성장된 수직 정렬된 산화아연 나노막대를 이용한 PDMS 표면의 미세패턴 형성하여 광학적 특성을 분석하였다. 실험을 위해, 스퍼터링을 통해서 산화아연 시드층을 형성한 후, 질산아연헥사수화물과 헥사메틸렌테트라민을 수용액에 담가두어 산화아연 나노막대를 성장시켰으며, PDMS의 베이스와 경화제의 질량비를 10:1으로 용액을 준비하여 수직 정렬된 산화아연 나노막대 표면을 casting method으로 코팅하여 열경화 처리하였다. 제작된 샘플의 형태, 구조 광특성을 관찰하기 위해서 전계방출형전자현미경, X선 회절 분석기, 분광 광도계를 이용하였다.

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Enhancement of Lowsintering Temperature and Electromagnetic Properties of (NiCuZn)-Ferrites for Multilayer Chip Inductor by Using Ultra-fine Powders (초미세 분말합성에 의한 칩인덕터용 (NiCuZn)-Ferrites의 저온소결 및 전자기적 특성 향상)

  • 허은광;강영조;김정식
    • Journal of the Microelectronics and Packaging Society
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    • v.9 no.4
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    • pp.47-53
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    • 2002
  • In this study, two different (NiCuZn)-ferrite which were fabricated by using ultra-fine powders synthesized by the wet processing and conventionally commercialized powder, were investigated and compared each other in terms of the low temperature sintering and electromagnetic properties. Composition of x and w in $(Ni_{0.4-x}Cu_xZn_{0.6})_{1+w}(Fe_2O_4)_{1-w}$ were controlled as 0.2 and 0.03, respectively. The sintering temperature were $900^{\circ}C$ for ultra-fine powders by way of initial heat treatment and $1150^{\circ}C$ for commercialized powders. The (NiCuZn)-ferrite by ultra-fine powders showed love. sintering temperature than that of commercialized powders by over $200^{\circ}C$, and excellent electromagnetic properties such as the quality factor which is a important factor in the multi-layered chip inductor. In addition, characteristics of B-H hysteresis, crystallinity, microstructure and powder morphology were analyzed by a vibrating sample method(VSM), x-ray diffractometer(XRD), transmission electron microscope (TEM) and scanning electron microscope(SEM).

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Evaluation of Risk Level for Damage of Marine Accidents In SRRs using Fuzzy Logic (퍼지로직을 이용한 해양사고 피해규모에 의한 해역별 위험수준 평가)

  • Jang Woon-Jae;Kwon Suk-Jae;Keum Jong-Soo
    • Proceedings of KOSOMES biannual meeting
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    • 2004.05b
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    • pp.1-6
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    • 2004
  • This paper suggests an evaluation of risk level for damage of marine accidents in SRRs. Qualitative analyses in words is sometimes priorior to quantative analyses in numeric symbols. This paper intoduces a concept of fuzzy theory with the plenty of related literature review and AHP in the Korean SRRs of RCC and RSC. The methodology of this paper is max . min composition of fuzzy extensive principle, defuzzifiation is centroid of gravity methods. At the result, the evaluation of risk level is especially over Serious for smarine accident of Taean, Gunsan, Mokpo, Yosu, Tongyoung, Busan SRR. This paper recommends that many Rescue Vessels and Equipments need to the reduction of risk level about those.

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Synthesis and characterization of LiCoO2 thin film by sol-gel process (Sol-gel법에 의한 LiCoO2 박막의 합성과 특성평가)

  • Roh, Tae-Ho;Yon, Seog-Joo;Ko, Tae-Seog
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.3
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    • pp.94-98
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    • 2014
  • $LiCoO_2$ thin film has received diverse attention as cathodes material of thin-film micro-batteries. In this study, $LiCoO_2$ thin films were synthesized on Au substrates by sol-gel spin coating method and an annealing process. Their structures were studied using X-ray diffraction and Raman Spectroscopy. The particle morphologies of these thin films were observed by Scaning electron microscope. From the results of X-ray diffractometry and Raman Spectroscopy analyses, it was found that as-grown films had the structure of spinel (LT-$LiCoO_2$) and layered-Rock-salt (HT-$LiCoO_2$) at $550^{\circ}C$ and $750^{\circ}C$ respectively. The annealed films at $650^{\circ}C$ were presumed to be the mixed state of these two types. Throlugh the scanning electron microscope, It was estimated that the particle size in as-grown films at $750^{\circ}C$, were larger crystilline particle than in those at the other lower temperature and well distributed in the film.

A Study on the Analytico-Synthetic Classification (분석적 합성식 문헌분류법에 관한 연구)

  • Oh Dong-Geun
    • Journal of the Korean Society for Library and Information Science
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    • v.32 no.2
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    • pp.55-76
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    • 1998
  • The first part of this article investigates the general characteristics and the advantages and disadvantages of the analytico-synthetic classification over the enumerative one. The second part analyzes the general steps and related problems in compiling an analytico-synthetic scheme, and investigates the steps further including facet analysis , choosing order in main classes, citation order and order in array : and adding notations, through an illustrative scheme for a matrimonial agency's records.

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CNN 을 이용한 단일영상 고해상도 복원 및 수용영역 확장을 통한 성능 향상

  • Park, Karam;Cho, Nam Ik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2019.11a
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    • pp.76-79
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    • 2019
  • 합성곱 신경망의 성능이 증가하면서 다양한 영상 처리 문제를 해결하기 위해 합성곱 신경망을 적용한 시도들이 증가하고 있다. 고해상도 복원 문제도 그 중 하나였으며, 보다 높은 성능을 얻기 위해 주로 신경망의 깊이를 깊게 하는 시도들이 있었다. 본 논문에서는 고해상도 복원 작업을 위한 합성곱 신경망의 성능 향상을 위해 깊이를 증가시키는 접근법이 아닌 수용영역을 확장시키는 접근법을 시도하였다. 논문에서 제시한 모델은 신경망 내부에 두 개의 브랜치를 두어, 하나의 브랜치는 Dilated Convolution 을 이용해 수용영역을 확장하는데 사용되며, 다른 하나는 이 브랜치를 통해 나온 feature 를 가공하는데 사용된다. 기본 모델은 EDSR 을 사용하였으며, 최종적으로 4.79M 의 파라미터로 평균 32.46dB 의 PSNR 을 보여주었다. 하지만 모델의 구조가 복잡하여 깊이를 늘이는 접근법을 적용하기 어렵다는 한계점이 있다.

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Analytical Study on Effect of Floor Slab for Progressive Collapse Resistant Capacity of Steel Moment Frames (철골모멘트골조의 연쇄붕괴저항성능에 대한 바닥슬래브의 효과에 관한 해석적 연구)

  • Kim, Seonwoong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.1
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    • pp.27-35
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    • 2014
  • In this study, an improved energy-based nonlinear static analysis method are proposed to be used for more accurate evaluation of progressive collapse potential of steel moment frames by reflecting the contribution of a double-span floor slab. To this end, the behavior of the double-span floor slab was first investigated by performing material and geometric nonlinear finite element analysis. A simplified energy-absorbed analytical model by idealizing the deformed shape of the double-span floor slab was developed. It is shown that the proposed model can easily be utilized for modeling the axial tensile force and strain energy response of the double-span floor slab under the column-removal scenario.