• 정보관리연구
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• 제39권4호
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• pp.67-96
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• 2008

오픈액세스 리포지터리는 법적, 경제적, 기술적 장벽 없이 전 세계 이용자 누구라도 자유롭게 무료로 정보에 접근할 수 있도록 생산자와 이용자가 정보를 공유할 수 있는 지식정보 저장소를 의미한다. 본 연구에서는 기관 리포지터리(dCollection, DSpace@MIT)와 주제별 리포지터리(arXiv, PubMed Central)로 구분하여 각 리포지터리에서 제공하는 기능분석과 비교를 실시하였고 분석된 자료를 기초로 이용자 중심의 사용성 평가를 실시하였다． 정보에 대한 자유로운 접근과 공유가 중요시 되는 웹 2.0시대라 불리고 있는 현 시점에서, 오픈액세스 리포지터리에 대한 사용성 평가를 실시함으로서 향후 구축되는 리포지터리 개발에 기초자료가 될 수 있다는 점에서 그 의의가 있다고 할 수 있다.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.37-43
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• 2008

The durability test of turbo-blower for PEM fuel cell is very important process of BOP development. It is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the air supply system to increase the reliability and to reduce the lifetime cost. In this study, turbo-blower supported by oil-free bearing is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. The impeller of blower was adopted mixed type of centrifugal and axial. So, it has several advantages for variable operating condition. The turbo-blower test results show maximum parasitic power levels below 1.67kW with the 30,000 rpm rotating speed, the flow rate of air has maximum 163SCFM(@PR1.1). For proper application of FCV, these have to durability test. This paper describes the experiment for confirming endurance and stability of the turbo-blower for 500 hours.

• 마이크로전자및패키징학회지
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• 제13권4호
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• pp.45-50
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• 2006

3D package의 SiP에서 구리의 via filling은 매우 중요한 사항으로 package밀도가 높아짐에 따라 via의 크기가 줄어들며 전기도금법을 이용한 via filling이 연구되어왔다. Via filling시 via 내부에 결함이 발생하기 쉬운데 전해액 내에 억제제, 가속제등 첨가제를 첨가하고 펄스-역펄스(PRC)의 전류파형을 인가하여 결함이 없는 via의 filling이 가능하다. 본 연구에서는 건식 식각 방법 중 하나인 DRIE법을 이용하여 깊이 $100{\sim}190\;{\mu}m$, 직경이 각각 $50{\mu}m,\;20{\mu}m$인 2가지 형태의 via을 형성하였다. DRIE로 via가 형성된 Si wafer위에 IMP System으로 Cu의 Si으로 확산을 막기 위한 Ta층과 전해도금의 씨앗층인 Cu층을 형성하였다. Via시편은 직류, 펄스-역펄스의 전류 파형과 억제제, 가속제, 억제제의 첨가제를 모두 사용하여 filling을 시도하였고, 공정 후 via의 단면을 경면 가공하여 SEM으로 관찰하였다.

• Macromolecular Research
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• 제12권4호
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• pp.413-421
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• 2004

Sulfonated poly(phthalazinone ether sulfone ketone) (SPPESK) membranes and sol-gel derived SPPESK/silica hybrid membranes have been investigated as potential polymer electrolyte membranes for direct methanol fuel cell (DMFC) applications. In comparison with the SPPESK membrane, the SPPESK/silica membranes exhibited higher water content, improved proton conductivity, and lower methanol permeability. Notably, the silica embedded in the membrane acted as a material for reducing the fraction of free water and as a barrier for methanol transport through the membrane. From the results of proton conductivity and methanol permeability studies, we suggest that the fractions of bound and free water should be optimized to obtain desirable proton conductivities and methanol permeabilities. The highly sulfonated PPESK hybrid membrane (HSP-Si) displayed higher proton conductivity (3.42 ${\times}$ 10$^2$ S/cm) and lower methanol permeability (4.15 ${\times}$ 10$\^$7/ $\textrm{cm}^2$/s) than those of Nafion 117 (2.54 ${\times}$ 10$^2$ S/cm; 2.36 ${\times}$ 10$\^$6/ $\textrm{cm}^2$/s, respectively) at 30$^{\circ}C$. This characteristic of the SPPESK/silica membranes is desirable for future applications related to DMFCs.

• 한국재료학회지
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• 제23권10호
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• pp.550-554
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• 2013

As continued scaling becomes increasingly difficult, 3D integration has emerged as a viable solution to achieve higher bandwidths and good power efficiency. 3D integration can be defined as a technology involving the stacking of multiple processed wafers containing integrated circuits on top of each other with vertical interconnects between the wafers. This type of 3D structure can improve performance levels, enable the integration of devices with incompatible process flows, and reduce form factors. Through silicon vias (TSVs), which directly connect stacked structures die-to-die, are an enabling technology for future 3D integrated systems. TSVs filled with copper using an electro-plating method are investigated in this study. DC and pulses are used as a current source for the electro-plating process as a means of via filling. A TiN barrier and Ru seed layers are deposited by plasma-enhanced atomic layer deposition (PEALD) with thicknesses of 10 and 30 nm, respectively. All samples electroplated by the DC current showed defects, even with additives. However, the samples electroplated by the pulse current showed defect-free super-filled via structures. The optimized condition for defect-free bottom-up super-filling was established by adjusting the additive concentrations in the basic plating solution of copper sulfate. The optimized concentrations of JGB and SPS were found to be 10 and 20 ppm, respectively.

• 한국자기학회지
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• 제16권3호
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• pp.186-191
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• 2006

자기터널접합 기반의 MRAM(magnetic random access memory)은 자기저항효과를 응용하는 메모리소자로서 비휘발성과 고속 정보처리가 가능할 뿐만 아니라 고집적화 할 수 있는 차세대 통합형 비휘발성 메모리이다. 그러나 기존의 메모리 소자들에 비해 스위칭 산포가 크고, 기록마진(writing margin)이 확보되지 않아 아직까지는 고집적화가 어려운 실정이다. 최근 포화자화가 낮은 NiFeSiB 및 CoFeSiB과 같은 비정질 강자성체를 자기터널접합의 자유층 재료로 사용하여 스위칭 자기장의 거대화를 크게 감소시켜 MRAM의 기록마진을 높이는 연구결과에 관해 정리하여 보았다. 그리고 이러한 물질을 이용하여 자기터널접합의 재생마진(reading margin)과 관련된 터널자기저항비의 인가전압의존성을 저감시킬 수 있었다. 본고에서는 나노자기소자 기술의 중요한 분야인 MRAM의 기술발전 방향과 연구사례를 소개하고자 한다.

• 교육녹색환경연구
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• 제21권1호
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• pp.1-10
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• 2022

기존 고등학교 공간 내의 무장애환경이 어느 정도의 수준으로 조성되어 있는지에 관해 파악하기 위해 본 연구는 서울시에 위치한 고등학교 177개소를 대상으로 장애인편의시설 적용 수준을 평가하여 이를 바탕으로 고등학교의 물리적 환경 개선의 방향성을 제시하였다. 2장에서 학교의 세부적인 시설관련 기준인 장애인 등 편의법과 장애인차별금지법의 기준과 선행연구를 고찰한 후, 3장에서는 장애인 등 편의법 규정을 토대로 고등학교 환경의 현장 실태조사를 실시하여 장애인 편의시설의 전반적인 적용수준과 장애인등 편의법 시행 전후 시기별 및 특수학급의 유무별로 적용수준을 평가하고 이를 분석하였다.

• Advances in materials Research
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• 제1권2호
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• pp.115-128
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• 2012

The structural and electrical properties of $(1-x)Ba(Sm_{1/2}Nb_{1/2})O_3-xBaTiO_3$; ($0{\leq}x{\leq}1$) ceramics were prepared by conventional ceramic technique at $1375^{\circ}C$/7 h in air atmosphere. The crystal symmetry, space group and unit cell dimensions were derived from the X-ray diffraction (XRD) data using FullProf software whereas crystallite size and lattice strain were estimated from Williamson-Hall approach. XRD analysis of the compound indicated the formation of a single-phase cubic structure with the space group Pm m. Dielectric study revealed that the compound $0.75Ba(Sm_{1/2}Nb_{1/2})O_3-0.25BaTiO_3$ is having low and ${\varepsilon}^{\prime}$ and ${\varepsilon}^{{\prime}{\prime}}$ a low $T_{CC}$ (< 5%) in the working temperature range (up to+$100^{\circ}C$) which makes this composition suitable for capacitor application and may be designated as 'Stable Low-K' Class I material as per the specifications of the Electronic Industries Association. The correlated barrier hopping model was employed to successfully explain the mechanism of charge transport in the system. The ac conductivity data were used to evaluate the density of states at Fermi level, minimum hopping length and apparent activation energy of the compounds.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제19권2호
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• pp.7-17
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• 2013

Purpose: This basic research tries to provide planning concept of elderly housing which can cope with the needs of the aged society. Methods: This study has been conducted mainly by literature investigation research. Previous researches include Universal and Barrier-Free Design, Elderly Housing Standards, Elderly Welfare Act and other related acts, various papers related to elderly housing, and so on. To set up the Planning concept of elderly housing, elements or indices of previous studies have been comparatively analysed. Results: Elderly housing has been divided into individual type, group type and facility type according to the residents' health and operation system of the housing. This paper focuses on the individual type among three categories. Seven concepts of the elderly housing have been derived as the outcome of this research - Safety, Accessibility, Amenity, Distinguishment, Adaptability, Convenience, and Sociality. Implications: This concept will provide the planning direction on the construction and renovation for Elderly Housing in the future.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제19권2호
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• pp.41-49
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• 2013

Purpose: Economic and social pressures are driving Korea to reform its mental health services. However, it is not easy for the governments to find to the proper method for the mental health service network. This study is to find the mental health service network in Japan. Methods: The survey was conducted by researches and field studies. 1) Researches for mental health service network and facilities. 2) Field study is for Mental Health and Welfare Network in Tokyo. Results: The result of this study can be summarized into three points. The first one, Reform measures are beginning to promote the concept of "normalization" in japanese society. The second one, Facilities of Mental health and welfare system designed by level that can be providing places for people with mental problems. The third one, Facilities consist of barrier-free environment for people with mental problems.