• Title/Summary/Keyword: 자기이력

Search Result 160, Processing Time 0.031 seconds

Magneto-optic effect of thermal evaporated amorphous TbFeCo thin flim (비정질 TbFeCo 합금 증착박막의 자기광학효과)

  • 박용관;양계준
    • Electrical & Electronic Materials
    • /
    • v.5 no.4
    • /
    • pp.439-445
    • /
    • 1992
  • 최근 광자기 기록매체로 주목받고 있는 RE-TM계 비정질 박막을 T $b_{x}$ (F $e_{0.9}$ $Co_{0.1}$)$_{100-x}$ (x=14, 17, 20, 23, 27[at%])의 조성비를 갖는 모합금을 만든후 진공증착방법으로 합금박막을 제작하였다. 각시료의 조성에 따른 자기광학효과를 알아보기 위하여 80K부터 600K에서 포화자화( $M_{s}$ )와 보자력( $H_{c}$)에 대한 온도의존성과 자기이방성상수(Ku), Polar Kerr 이력곡선을 측정하였다. 또한 Curie 온도 근처에서 열처리 시간에 따른 자기 토크 곡선의 변화를 분석 함으로써 합금박막 표면의 산화정도를 정성적으로 평가할 수 있었다. 실험결과 T $b_{22.72}$(F $e_{68.78}$ $Co_{8.5}$)인 시료가 상온에서 8.4KOe의 보자력을 가졌으며 T $b_{x}$(x=23[at%])인 경우가 가장 큰 수직자기이방성을 나타냈다. Polar Kerr 이력곡선은 Tb함량 x=25~26[at%]에서 부호가 반전됨을 알 수 있었다.다.다.다.

  • PDF

Dynamic Migration Strategy of Image Data in PACS (의료영상 저장 전송 시스템에서 영상 데이터의 동적 이동 기법)

  • 이순희;윤홍원
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2000.04b
    • /
    • pp.116-118
    • /
    • 2000
  • 의료영상 저장 전송 시스템에서 환자의 이력 영상은 시간이 지나면서 데이터의 양이 급격히 증가하므로 자기 디스크에서 제 3의 저장 장치로 데이터를 옮기고 있다. 일정한 보존 기간이 경과하면 옮기는 기존의 이동 방법은 곧 검색될 영상을 자기 디스크에서 제 3의 저장 장치로 옮길 가능성이 높다. 이 문제점을 해결하기 위해서 이력 영상의 검색 속도를 향상시키는 두 가지 이동 기법 AIP와 EAIP 제안하였다. 두 기법 모두 기존의 방법보다 검색 속도가 우수하였다. 제안하는 두 가지 이동 기법 사이의 질의 처리 속도를 비교하였는데 EAIP가 우수하였다. 또한, EAIP 이동 기법을 이용한 이동 실행기를 구현하였다.

  • PDF

Magnetic Hysteresis Monitoring according to the Change of Tensile Force and Steel Class of PS Tendons (PS 텐던 강종별 긴장력 변화에 따른 자기이력 모니터링)

  • Kim, Junkyeong;Park, Seunghee;Lee, Hwanwoo
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.31 no.2
    • /
    • pp.115-120
    • /
    • 2018
  • This paper introduces a magnetic hysteresis monitoring result to apply an EM sensing technique for estimating tensile force of PSC girder to various class of PS tendon. The tensile force of PS tendon is a very important factor in the performance evaluation of PSC bridges. However, in this time, the tensile force was just measured only during construction and it does not monitored after construction. To measure the tensile force of PS tendons, the EM sensing based NDT method was developed but the proposed method cannot be applied to various class of PS tendons. Thus this study performed the magnetic hysteresis measurement according to the tensile force for class B, C and D PS tendons through experimental study. The specific tensile forces(50, 100, 150, 180kN) were induced to the each specimens and the magnetic hysteresis curve was measured at each point. The permeability of specimens were gradually decreased according to increase of tensile force. Especially, the slopes of permeability variation of class B and C were similar while that of class D was different.

Effect of Long-Term Aging Degradation on Magnetic Properties of Ferritic 11Cr Low-Carbon Steel (페라이트기 11Cr 저탄소강의 자기적 특성에 대한 고온 장시간 시효열화 효과)

  • Kim, Chungseok;Ryu, Kwon-Sang
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.36 no.5
    • /
    • pp.377-383
    • /
    • 2016
  • The effect of long-term aging degradation on magnetic properties of ferritic 11Cr low-carbon steel was investigated. Coercivity and hysteresis loss measured from the hysteresis loops decreased with long-term aging time and showed that the relation was well fitted by a second order exponential function. Vickers hardness also decreased with aging time and resulted in mechanical softening. In addition, the microstructural evolution was observed by the scanning electron microscopy, backscattered electron image and X-ray diffraction. The $Cr_{23}C_6$ precipitates along grain boundary grew fast and Laves ($Fe_2W$) phase on martensitic lath boundaries in interior grains was developed. The solid solution atoms depleted in matrix and lath subgrains recovered owing to precipitate coarsening with long-term aging degradation. There was a close relation with softening of magnetic and mechanical properties.

Exploring a Researcher's Personal Research History through Self-Citation Network and Citation Identity (자기 인용 네트워크와 인용 정체성을 이용한 연구자의 연구 이력 분석에 관한 연구)

  • Lee, Jae-Yun
    • Journal of the Korean Society for information Management
    • /
    • v.29 no.1
    • /
    • pp.157-174
    • /
    • 2012
  • This paper compares two recent methods for exploring a scientist's research history: citation identity and self-citation network. The former is proposed by White(2000), while the latter is suggested by Hellsten et al.(2007). An experimental citation analysis was carried out on the research output of Young Mee Chung, a renouned Korean information scientist. The result shows that the two methods divided the research period into two sub-periods in the same way. They also identified the major research themes very similarly. In the analysis of each method's performance in depth, the two methods revealed different functions to understand a researcher's history. Citation identity was useful to identify authors who have affected Chung's research in terms of research topics. whereas, self-citation network was successful to identify the core papers and leading papers of the research sub-periods. This study indicates the combination of two methods can provide rich information on a scientist's research history.