• Title/Summary/Keyword: 코아

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Dublin Core-based Union Cataloging System for Journal Articles (더블린 코아 기반 학술지논문 종합목록 시스템)

  • 이해민;채진석;최한석;김성혁
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10b
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    • pp.380-382
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    • 1998
  • 학술연구를 수행하는데 도움이 되는 중요한 정보 중의 하나는 학술연구자가 연구 중인 분야의 최신 논문에 대한 원문 정보와 이 논문이 실려 있는 학술지의 소장 정보라고 할 수 있다. 이러한 정보를 효과적으로 학술 연구자에게 제공하기 위해 첨단학술정보센터(Korea Research Information Center: KRIC)에서는 전문학술정보센터(Special Research Information Center: SRIC)로 지정된 대학도서관에서 구독하는 학술지에 게재된 논문에 대한 목록 데이터를 통합하는 학술지논문 종합목록 시스템을 구축 중이다. 이 시스템에서는 기존의 대학도서관에서 사용하고 있는 목록기술규칙인 MAEX(MAchine Readable Cataloging)대신 인터넷 기반의 디지털 도서관에 적합한 형태를 가지는 더블린 코아를 새로운 목록기술규칙으로 채택하였다. 이러한 더블린 코아를 사용하게 되면 목록자는 전문적인 교육 없이도 간편하게 새로운 목록을 작성할 수 있다. 학술지논문 종합목록이 구축되면 학술연구자들은 원하는 논문이 검색된 경우, 원문이 구축되어 있으면 인터넷을 통해 곧바로 원문을 볼 수 있고, 원문이 구축되어 있지 않다면 복사/팩스 서비스 시스템을 통해 원문을 제공받을 수 있게 된다.

Minerals in the Core Sediments from the KONOD-1 Area;Northeastern Equatorial Pacific (북동 태평양 적도대 KONOD-1지역 코아 퇴적물 중의 광물에 대한 연구)

  • 한상준;정갑식
    • 한국해양학회지
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    • v.22 no.3
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    • pp.119-129
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    • 1987
  • Sediments in the cores from the KONOD-1 area consist mainly of authigenic smectite and clinoptilolite, and terrigenous minerals of illite, chlorite, kaolinite, quartz, and plagioclase. The authigenic minerals become dominant over the terrigenous minerals with increasing depth. Clinoptilolite occurs at the deeper core depth because its formation is slower than that of smectite. The vertical distribution of minerals indicates that the eolian influence, probably in the late Oligocene, diluted the abundance if smectite in near-surface sediments. This vertical distribution pattern may also have been affected by progressive dissolution of authigenic minerals in the near surface sediments.

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A Study on the Optimization of the Optical Coupler for Wavelength Division (파장 분할 광 결합기의 최적화에 관한 연구)

  • 윤성현;정만영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.2
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    • pp.177-187
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    • 1989
  • When wavelength division optical coupler is fabricated with the polished single mode optical fiber, coupling coeffiecient differ from wavelength and distance to two cores. Wavelength division is function of the differential coupling coefficient to distance of two cores. This paper suggests the condition of the minimum spacing of the wavelength division with the function of the distance of two cores.

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The characteristic of Er$^+$:SiO$_2$thin film preparation by rf sputtering method (고주파 스펴터링에 의한 Ef$^+$:SiO$_2$ 박막 제작 특성)

  • 최영복;조승현;정성훈;문동찬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.90-93
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    • 1997
  • 고주파 반응성 스퍼터링 방법을 사용하여 희토류가 첨가된 SiO$_2$ 박막을 제작하여 특성을 조사하여, 양질의 희토류 원소가 첨가된 SiO$_2$ 박막의 최적의 제작조건을 도출하고 Er-Al:SiO$_2$ 박막의 소자웅용 가능성에 대하여 조사하였다 열처리전의 Er의 농도는 EDS(Energy dispersing x-ray spectrometer)로 측정한 결과 0.77% 로 농도를 나타내었고 코아층 첨가된 Er은 균일하게 분포되었다 크레드층의 굴절률은 633nm의 파장에서 측정하였을때 1.458이였고 코아층의 굴절률은 동일 파장에서 1.757이였다. 굴절률 분포도 (Refractive Index Profile)는 계단형 굴절률 분포로 코아층/클래드 굴절률 차 $\Delta$n$_{ESI}$ = 0.1였다.

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Evaluation of the Sealing Capacity of the Supercritical CO2 by the Measurement of Its Injection Pressure into the Tuff and the Mudstone in the Janggi Basin (초임계이산화탄소(scCO2) 주입압력 측정에 의한 장기분지 응회암과 이암의 scCO2 차폐능 평가)

  • An, Jeongpil;Lee, Minhee;Wang, Sookyun
    • Economic and Environmental Geology
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    • v.50 no.4
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    • pp.303-311
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    • 2017
  • The laboratory scale experiment was performed to evaluate the sealing capacity of the capping rock such as tuff and mudstone, measuring the intial supercritical $CO_2$ ($scCO_2$) injection pressure and the $scCO_2$-water-rock reaction for 90 days. The drilling cores sampled from 800 m in depth around the Janggi basin, Korea were used for the experiment. The mineralogical changes of mudstone and tuff were measured to evaluate the geochemical stability during the $scCO_2$-water-rock reaction at $CO_2$ storage condition (100 bar and $50^{\circ}C$). The rock core was fixed in the high pressurized stainless steel cell and was saturated with distilled water at 100 bar of pore water pressure. The effluent of the cell was connected to the large tank filled with 3 L of water and 2 L of $scCO_2$ at 100 bar, simulating the subsurface injection condition. The $scCO_2$ injection pressure, which was higher than 100 bar, was controlled at the influent port of the cell until the $scCO_2$ begin to penetrate into the rock and the initial injection pressure (> 100 bar) of $scCO_2$ into the rock was measured for each rock. The mineralogical compositions of mudstones after 90 days reaction were similar to those before the reaction, suggesting that the mudstone in the Janggi basin has remained relatively stable for the $scCO_2$ involved geochemical reaction. The initial $scCO_2$ injection pressure (${\Delta}P$) of a tuff in the Janggi basin was 15 bar and the continuous $scCO_2$ injection into the tuff core occurred at higher than 20 bar of injection pressure. For the mudstone in the Janggi basin, the initial $scCO_2$ injection pressure was higher than 150 bar (10 times higher than that of the tuff). From the results, the mudstone in Janggi basin was more suitable than the tuff to shield the $scCO_2$ leakage from the reservoir rock at subsurface.

Magnetic Properties of NixFe100-x(x=40~50) Permalloy Powders and Dust Cores Prepared by Gas-Atomization (가스 분무법으로 제조된 NixFe100-x(x=40~50) 퍼멀로이 분말 및 압분 코아의 자기적 특성)

  • Noh, T.H.;Kim, G.H.;Choi, G.B.;Kim, K.Y.
    • Journal of the Korean Magnetics Society
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    • v.12 no.6
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    • pp.218-223
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    • 2002
  • We investigated the magnetic properties of High Flux-type $Ni_{x}Fe_{100-x}$(x=40∼50, wt.%) permalloy powders and dust cores. The powder was prepared by conventional gas atomization in mass production scale. At the composition of $Ni_{x}Fe_{55}$, saturation magnetization was maximum. In case of lower Ni content than X=45, the $M_{s}$, decreased largely with the decrease in Ni content, which is due to the invar effect. The permeability of compressed powder cores increased with the decrease in Ni content, which was considered to be due to the decrease in the magnetostriction. In addition, the dust core with Ni=45% showed the lowest core loss because of the increase in electrical resistivity leading to the low eddy current loss. From the better frequency dependence of permeability, larger Q value and superior DC bias characteristics of Ni=45% than those of Ni=50% core, it was confirmed that the 45%Ni-55%Fe powder alloy was better material for the dust core than commercial High Flux core materials.

Static and Fatigue Characteristics of Urethane Foam Cored Sandwich Structures (우레탄 폼 코아 샌드위치 구조물의 정적 및 피로 특성)

  • 김재훈;이영신;박병준;김덕회;김영기
    • Composites Research
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    • v.12 no.6
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    • pp.74-82
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    • 1999
  • The static and fatigue characteristics of polyurethane foam cored sandwich structures are investigated. Three types of the specimens with the glass fabric faces and the polyurethane foam core are used; non-stitched. stitched, and stiffened sandwich specimen. Especially additional structural reinforcements with the twisted polyester and glass fiber for thickness direction are made to stitched sandwich structure panel to minimize the delamination of structure which is stitched the upper and lower faces through the core and the resin is impregnated Into stitched fiber with the characteristics of low viscosity of resin at resin flow temperature and cured together with during the curing process. Bending strength of stitched specimen which is 50 mm $50{\times}50{\;}mm$ pitched is improved by 50 % as com-pared with non-stitched specimen and stiffened specimen is improved 10 times more than non-stitched structure. After fatigue testing of $10^6$cycles by 20% of ultimate load under monotonic load, the bending fatigue strength of non-stitched specimen is decreased by 27% of monotonic bending strength, 39% for stitched structure and 20% for stiffened specimen. To verify the aging effect of polyurethane form core, Ultrasonic C-scanning equipment is used to detect the damage of skin laminate alone after fatigue test. From results of UT C-scan images, there is no defect that can be damaged occurred during fatigue test. It is concluded that the decrease of bending strength for foam cored sandwich specimen is caused by the decrease of stiffness due to the aging of polyurethane foam core during fatigue cycles.

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Determination of lercanidipine in human plasma by LC-MS/MS (LC-MS/MS를 이용한 혈장 중 레르카니디핀의 분석)

  • Jang, Moon-Sun;La, Sookie;Chang, Kyu Young;Kang, Seung Woo;Han, Sang Beom;Lee, Kyung Ryul;Lee, Hee Joo
    • Analytical Science and Technology
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    • v.21 no.1
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    • pp.34-40
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    • 2008
  • Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantitative determination of lercanidipine in human plasma. After addition of internal standard (amlodipine), plasma was precipitated with acetonitrile and the supernatant was evaporated. The residues were dissolved in 50 % acetonitrile and analyzed by LC-MS/MS. Using MS/MS with multiple reaction monitoring(MRM) mode, lercanindipine were selectively detected without severe interference from human plasma. The standard calibration curve for lercanidipine was linear (r = 0.9994) over the concentration range 0.05-20.0 ng/mL in human plasma. The intra- and inter-day precision over the concentration range of lercanidipine was lower than 11.7 % (correlation of variance, CV), and accuracy was between 94.4-114.8 %. This method has been successfully applied to the pharmacokinetic study of lercanidipine in human plasma.

Fe계 나노결정 연자성코아의 개발동향

  • 조현정;박원욱
    • Journal of Powder Materials
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    • v.11 no.4
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    • pp.348-350
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    • 2004
  • 최근 들어 노트북, 통신장비 등 고성능 전자기기들은 산업수요의 특성상 소형화와 경량화 추세가 가속화되고 있으며, 컴퓨터, 냉장고, 에어컨 등 가전제품에 있어서도 안정한 전류공급 및 역률의 향상이 의무화되고 있다. 따라서 내부에 사용되는 부품의 고주파화, 고효율화, 손실감소를 위한 고성능 연자성코아 (그림 1. 참조) 개발의 필요성이 한층 증대되고있는 실정이다. (중략)