• Title/Summary/Keyword: 구조적 안정도

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Optical Properties of $TiO_2$ Thin Films Prepared by Ion-beam Assisted Deposition (이온빔 보조 증착법에 의해 제작된 $TiO_2$ 박막의 광학적 특성)

  • 조현주;이홍순;황보창권;이민희;박대윤
    • Korean Journal of Optics and Photonics
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    • v.5 no.1
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    • pp.9-17
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    • 1994
  • Optical properties of $TiO_2$ thin films prepared by ion-beam assisted deposition(1BAD) were investigated. The result shows that the refractive index of IBAD TiOL thin films measured by an envelope method is closer to that of the corresponding bulk than that of conventionally deposited $TiO_2$ thin films and the packing density of IBAD $TiO_2$ thin films measured by a vacuum-to-air spectral shift of films increases drastically. The vacuum-to-air spectral shift of an IBAD $(TiO_2/SiO_2)$ multilayer interference filter was negligible as compared to that of a conventional interference filter and so the IBAD filter is denser and more stable optically than the conventional filter. Also it is observed that the IBAD and conventional $TiO_2$ thin films are stoichiometric and amorphous.

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반응성 스퍼터링에 의한 마이크로 박막 전지용 산화바나듐 박막의 제작 및 전기화학적 특성평가

  • 전은정;신영화;남상철;조원일;윤영수
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.49-49
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    • 1999
  • 리튬 이차 전지를 박막화함으로써 개발된 고상의 마이크로 박막전지는 임의의 크기 및 형태로의 제작이 가능하며 액체전해질을 사용하지 않기 때문에 작동 중 열 또는 기체 생성물이 생기지 않아 높은 안정성을 갖으며 광범위한 사용 온도 범위를 가진다. 위와 같은 장점으로 인하여 충전 가능한 고상의 박막형 리튬 이차 전지는 점진적으로 그 사용 범위가 크게 확대될 것으로 판단된다. 즉, 초소형 전자, 전기 소자는 물론이며 조만간 실현될 스마트 카드, 셀루러폰 및 PCS와 같은 개인용 휴대 통신장비의 전력 공급계로의 응용이 가능할 것이다. 특히 장수명, 고에너지 밀도를 갖는 초소형의 전지를 필요로 하는 microelectronics, MEMS등에 이용될 수 있는 이차전지에 대한 요구가 점점 가시화 됨에 따라 박막공정을 이용한 이차전지개발기술이 요구되고 있으며, 박막제조기술을 이용한 고상의 박막형 및 전지에 관한 연구가 증가하고 있다. 본 연구에서는 박막형 리튬 이차전지의 Cathode 물질로써 비정질의 산화바나듐 박막을 반응성 스퍼터링에 의하여 상온에서 증착하였다. 박막형 이차전지의 여러 가지 Cathode 물질중 산화바나듐은 다른 물질들과는 달리 비정질 형태로 매우 우수한 충방전 특성을 나타낸다. 이런 특성으로 인해 다소 전지자체의 성능은 낮지만 저전력 저전압을 필요로 하는 초소형 전자 소자와 혼성되어 이용할 수 있는 잠재성이 매우 높은 물질이다. 바나듐 타겟의 경우 타겟 표면의 ageing에 따라 증착되는 박막의 특성이 매우 달라지게 되므로 presputtering의 시간을 변화시키면서 실험하였다. 또한 스퍼터링 중의 산소의 분압도 타겟의 ageing에 많은 영향을 주므로 실험 변수로 산소분압을 변화시키면서 실험하였다. 증착된 산화바나듐 박막의 표면은 scanning electron microscopy로 분석하였으며 구조 분석은 X-선 회절분석, X-ray photoelectron spectroscopy 그리고Auger electron spectroscope로 하였다. 증착된 산화바나듐 박막의 전기화학적 특성을 분석하기 위하여 리튬 메탈을 anode로 하고 EC:DMC=1:1, 1M LiPF6 액체 전해질을 사용한 Half-Cell를 구성하여 200회 이상의 정전류 충 방전 시험을 행하였다. Half-Cell test 결과 박막의 결정성과 표면상태에 따라 매우 다른 전지 특성을 나타내었다.

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Analysis of Judgements on the validity of selective/unilateral Arbitration Agreement - In case of the Supreme Court's Judgements - (선택적 중재합의의 유효성에 대한 판례분석 - 대법원 판례를 중심으로 -)

  • Chung, Young-Hwan
    • Journal of Arbitration Studies
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    • v.19 no.3
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    • pp.3-24
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    • 2009
  • This article discusses the validity of selective/unilateral arbitration agreement that provides arbitration as one of several dispute resolution methods. The Supreme Court has held selective/unilateral arbitration agreement that is conditional invalidity since the judgement of 2003Da318 decided on Aug. 22, 2003: In the following judgements of 2004Da42166 decided on Nov. 11, 2004 and 2005Da12452 decided on May 27, 2005, the Court stated that the selective/unilateral arbitration agreement that stipulates to resolve a dispute through arbitration or mediation would be valid as an effective arbitration agreement only if a party elects and proceeds an arbitration proceeding and another party responses to the arbitration proceeding without any objection. The definition of arbitration agreement, the formation of selective/unilateral arbitration agreement, the summary of relative judgements and academic theories will be reviewed in order to examine the appropriateness of the series of judgements of the Supreme Court. Based on such reviews, this article will investigate the adequacy of the Supreme Court judgements from the perspectives of i) the principle of party autonomy, ii) the structure of dispute resolution methods, iii) legal provisions of Arbitration Act, iv) legal stability, and v) the policy to revitalize the use of arbitration. At conclusion, this article will suggest the change of precedents of the Supreme Court's judgements with regard to the selective arbitral agreement.

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Management Efficiency of Forest Tending Works by Using Data Envelopment Analysis (DEA(Data Envelopment Analysis)기법을 이용한 숲가꾸기 사업의 경영 효율성 분석)

  • Woo, Hee Sung;Woo, Jong Choon;Won, Hyun Kyu
    • Journal of Korean Society of Forest Science
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    • v.101 no.4
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    • pp.729-736
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    • 2012
  • Korea Forest Service is recently focused on forest tending works for promoting in green jobs. The purpose of forest tending work is not only maintaining ecologically stable forest stand structure but also developing commercial forest. These trends are also emphasized by creation of various benefits and expanding carbon absorption in forest management. For achieving these purposes, Management efficiency of output was analized by the inputs such as labor cost, material cost and expense cost using DEA technique. The results show that, 19 sub-compartments are appeared to be the optimal in the efficiency of the forest tending works among total 52 sub-compartments. Among those there were 5 sub-compartment 8-0-3, 9-3-3, 6-0-3, 7-0-6, 1-0-5 and 3-0-3 to be considered in the high reference. The high reference areas mean those areas which is well accomplished in forest tending works as the desirable model.

Evaluation of Fluid Forces Acting on Offshore Structures Placed in the Vicinity of Underwater Shoal (수중 천퇴 인근에 설치된 해양구조물에 작용하는 유체력 결정에 대한 고찰)

  • Chun, In-Sik;Min, In-Ki;Sim, Jae-Seol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.2
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    • pp.136-145
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    • 2007
  • When waves propagating over an underwater shoal break at the top of the shoal, wave heights are drastically decreased in the downstream breaking zone, but a secondary current shooting downstream with strong velocity can be induced by the breaking waves themselves. In the case that an offshore structure is placed in the breaking zone, the estimation of wave farce purely based on the visible wave height may cause an under-design of the structure. Thus, for the safe design of the structure, the breaking wave induced current should be necessarily considered in the comprehensive estimation of design load. In the present study, Boussinesq equation model to calculate the wave height distribution and breaking wave induced current was set up and applied to the scheme of a hydraulic model test previously undertaken. Based on the results of the Boussinesq model, fluid forces acting on the model structure were calculated and compared with the experimental results. The importance of the breaking wave induced current was quantitatively assessed by comparing fluid forces with or without current.

Mineral Economic Index and Comprehensive Demand Prediction for Strategic Minerals: Copper, Zinc, Lead, and Nickel (자원경제지표와 주요 금속의 중.장기 수요 예측 -아연, 납, 구리, 니켈을 중심으로-)

  • Choi, Soen-Gyu;Kim, Chang-Seong;Ko, Eun-Mi;Kim, Seong-Yong;Jo, Ho-Young
    • Economic and Environmental Geology
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    • v.41 no.3
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    • pp.345-357
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    • 2008
  • Korea has been one of the top ranked countries in the per capita and total consumption of Cu, Zn, Pb, and Ni since economic development based on manufacturing industries. The current instability of mineral demand and supply in Korea is likely to continue or exacerbate in accordance with economic growth in developing countries such as BRICs. Korea needs to increase the self-development portion of strategic mineral resources including Cu, Zn, Pb, and Ni. Our analysis of mineral demand and supply data predicts a long-run instability of supply and demand for main minerals used in the Korean manufacturing industries, and suggests a long range government policy for stable supply of core mineral resources.

A Study on the Legislation Directions of FRAMEWORK ACT ON KOREA COAST GUARD(tentative name) ((가칭) 해양경찰기본법 입법방향에 관한 연구)

  • Son, Yeongtae
    • Journal of the Society of Disaster Information
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    • v.10 no.3
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    • pp.396-407
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    • 2014
  • In 19th May 2014, the government announced that KCG(Korea Coast Guard) is dissolved regarding responsibility for recently accident which is Sewol ferry disaster. But KCG, a central administrative agency is responsible for protecting maritime sovereignty of South Korea; the most basic and indispensable organization. Furthermore, The purpose of KCG is to provide the safety of the public and keeping of public order by prescribing matters necessary for the securement of maritime security, maintenance of public order and protection of marine resources & facilities. Therefore, In this article, I would like to suggest tentatively named FRAMEWORK ACT ON KOREA COAST GUARD's management plan which could reflect the scope of functions. It means we examine the current state of KCG, and would like to signpost for the most ideal way of legal system in Korea Coast Guard. Finally, this treatise is expected that this research can be a guideline contribute to improving Korea Coast Guard relevant laws even a little.

A Study on Shear Strength under Constant Normal Load Conditions by Using 3DEC (3DEC을 이용한 일정수직하중 조건에서의 전단강도에 관한 연구)

  • Noh, Young-Mok;Mun, Hong-Ju;Kim, Ki-Ho;Jang, Won-Yil
    • Tunnel and Underground Space
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    • v.24 no.1
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    • pp.46-54
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    • 2014
  • Direct shear tests have been initiated to understand the characteristics of joints which crucially affect the stability of rock mass. In this research, numerical approach in direct shear tests has been initiated using 3DEC on the basis of 3D distinct element method. Normal loads were altered in four different levels on artificial joint tests depending on the sawtooth angle and strengths on constant normal stress conditions, measuring the peak shear strength according to the direct shear tests under laboratory condition. Also results obtained from mechanical properties through laboratory test were used to perform numerical modeling, and shear strength obtained from the modeling was used to compare with laboratory direct shear test. As a result numerical analysis from distinct element method can simulate well on the shear behavior of rockmass.

Study on Availability about the Dielectric Constant of SiOC Thin Film (SiOC 박막의 허용 가능한 유전상수 설정에 대한 연구)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
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    • v.19 no.5
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    • pp.347-352
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    • 2010
  • To research the reduction of the dielectric constant depending on the ionic and electronic effects, the dielectric constant of SiOC film was obtained by C-V measurement using the structure of metal/SiOC film/Si, and $n^2$ calculated by the refractive index. The dielectric constant of SiOC film consists with dipole, ions and electrons. However, the dipole moment is ignored in the effect of dielectric constant in SiOC film. THe SiOC film was deposited by the plasma energy, and the gas precursor was dissociated and recombined. Therefore, the dielectric constant of the deposited film consisted of the polarity with ions. THe dielectric constant decreased after annealing process, because of the evaporation of OH hydroxyl group with polarity. The ideal SiOC film as low-k materials was annealed film with lowering the polarity, which is suitable for physical-chemical and electrical properties as an inter layer dielectric materials.

표면변형에 따른 실리콘 태양전지의 전력변환효율 변화

  • Lee, Se-Won;O, Si-Deok;Sin, Hyeon-Uk;Jeong, Je-Myeong;Kim, Tae-Hwan;Sin, Jae-Cheol;Kim, Hyo-Jin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.387-387
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    • 2012
  • 결정 Si 및 비정질 Si 태양전지는 환경친화적이며 안정적인 물질로 전력변환 및 에너지 저장 장치에 중요하기 때문에 연구가 활발하게 진행되고 있다. 고효율 Si 태양전지를 제작하여 상용화하기에는 여러 가지 문제점이 있다. 공기와 비교하여 높은 굴절률을 갖고 있기 때문에 발생하는 반사를 줄이기 위해서 필요한 무반사 코팅층(Anti-reflective coating; ARC)은 주로 SiO2 와 SiNx 와 같은 유전체를 이용하여 사용하지만 이들 ARC 증착은 PECVD와 같은 진공장비를 사용하므로 제작 비용이 높아지는 단점이 있다. 나노선 또는 나노 팁과 같은 sub-wavelength 구조를 표면에 만들어 반사율을 줄이는 작업을 통해 ARC 공정비용을 감소하고 효율을 증진하는 연구가 활발히 진행되고 있다. CdS 양자점을 태양전지 표면에 형성함으로 ARC로 해결할 수 없는 단파장영역에 해당하는 부분을 줄이는 연구가 진행되었으며, 비정질의 경우 원기둥 형태의 태양전지 형태와 더불어 지름 방향으로의 PN 접합 나노로드 배열을 만들어 흡수면을 증가하여 효율을 증가한 연구도 진행되었다. 태양전지 표면의 형태를 V-groove 형태로 형성하여 입사하는 태양전지의 광밀도를 증가하는 이론적 결과도 발표되었다. 본 연구에서는 Si 태양전지의 표면변형에 따른 태양전지의 전력변환효율의 변화를 관찰하기 위하여 태양전지 표면의 texture 지름을 $3{\sim}15{\mu}m$, 간격을 $5{\sim}20{\mu}m$로 변화하고, 태양전지 표면의 나노 패턴을 2~10 nm 로 변화하여 반사율과 전력변환효율을 비교하였다. 나노와 마이크로 패턴은 각각 polystyrene nanosphere 와 photo mask를 이용하여 제작하였으며 PN junction Si 태양전지는 spin on dopant 방식으로 제작하여 성능을 조사하였다.

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