• Title/Summary/Keyword: 자기현상

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Statistical Relationship between Sawtooth Oscillations and Geomagnetic Storms (Sawtooth 진동 현상과 지자기 폭풍의 통계적 관계)

  • Kim, Jae-Hun;Lee, Dae-Young;Choi, Cheong-Rim;Her, Young-Tae;Han, Jin-Wook;Hong, Sun-Hak
    • Journal of Astronomy and Space Sciences
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    • v.25 no.2
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    • pp.157-166
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    • 2008
  • We have investigated a statistical relationship between sawtooth oscillations and geomagnetic storms during 2000-2004. First of all we selected a total of 154 geomagnetic storms based on the Dst index, and distinguished between different drivers such as Coronal Mass Ejection (CME) and Co-rotating Interaction Region (CIR). Also, we identified a total of 48 sawtooth oscillation events based on geosynchronous energetic particle data for the same 2000-2004 period. We found that out of the 154 storms identified, 47 storms indicated the presence of sawtooth oscillations. Also, all but one sawtooth event identified occurred during a geomagnetic storm interval. It was also found that sawtooth oscillation events occur more frequently for storms driven by CME $({\sim}62%)$ than for storms driven by CIR $({\sim}30%)$. In addition, sawtooth oscillations occurred mainly $({\sim}82%)$ in the main phase of storms for CME-driven storms while they occurred mostly $({\sim}78%)$ during the storm recovery phase for CIR-driven storms. Next we have examined the average characteristics of the Bz component of IMF, and solar wind speed, which were the main components for driving geomagnetic storm. We found that for most of the sawtooth events, the IMF Bz corresponds to -15 to 0 nT and the solar wind speed was in the range of $400{\sim}700km/s$. We found that there was a weak tendency that the number of teeth for a given sawtooth event interval was proportional to the southward IMF Bz magnitude.

A Phenomenological Study of Song Psychotherapy for the Self-Exploration of Children of Ministers (목회자 자녀의 자기탐색을 위한 노래심리치료에 대한 현상학적 연구)

  • Choi, Sul Ki
    • Journal of Music and Human Behavior
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    • v.8 no.1
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    • pp.17-42
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    • 2011
  • The purpose of the present study was to look deeply into the experience of self-exploration by providing song psychotherapy to the children of ministers. For this, three women, who were children of ministers and who were in their twenties, were provided with fifteen sessions of song psychotherapy at the Music Therapy Clinic of E University. The present study used Colaizzi's phenomenological method in order to observe and understand the self-exploring process of the participants in depth. Therefore, the present research found 164 meaning units, 38 themes and 14 theme groups, and 3 categorizations. As a result of this study, first, the participants recognized the features of environment while exploring themselves in song psychotherapy. Second, they found their affectedness by and reactions about surrounding environments. Third, they found an intrapersonal condition that was formed by their surrounding environment. With this as the basis, the result of the present study helps form an understanding of the phenomena that the children of ministers experience, and it may be utilized as groundwork in the application and development of music therapy methods for the self-exploration of the children of ministers.

Simulations of Self-Assembled Structures in Macromolecular Systems: from Atomistic Model to Mesoscopic Model (고분자 자기조립 구조의 전산 모사: 원자 모델로부터 메조 스케일 모델까지)

  • Huh, June;Jo, Won-Ho
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.453-463
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    • 2006
  • Molecular simulation is an exceptionally useful method for predicting self-assembled structures in various macromolecular systems, enlightening the origins of many interesting molecular events such as protein folding, polymer micellization, and ordering of molten block copolymer. The length scales of those events ranges widely from sub-nanometer scale to micron-scale or to even larger, which is the main obstacle to simulate all the events in an ab initio principle. In order to detour this major obstacle in the molecular simulation approach, a molecular model can be rebuilt by sacrificing some unimportant molecular details, based on two different perspectives with respect to the resolution of model. These two perspectives are generally referred to as 'atomistic' and 'mesoscopit'. This paper reviews various simulation methods for macromolecular self-assembly in both atomistic and mesoscopic perspectives.

자기변형재료를 이용한 초정밀 액추에이터개발

  • 황진동;김선호;안증환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.138-138
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    • 2004
  • 자기변형(magnetostriction)이란 강자성을 띤 재료가 외부에서 인가된 자장에 놓이게 될 경우 재료의 자구 내에서 자기모멘트가 자장방향으로 정렬하면서 물체의 크기가 변하는 현상이다. 자기변형 재료는 가장 보편적으로 사용되고 있는 PZT보다 최고 10배 이상의 자기변형율을 가지면서 직경(20mm)에서 약 12kN의 힘을 발생시킬 수가 있고 자기장 방향과는 무관하게 항상 양의 자기변형을 가지는 재료이다. 주변형이 일어나는 영역에서의 자기변형은 자장에 선형적으로 비례한다.(중략)

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The Magnetoresistance effects of number of layers and magnetic anisotropic in [NiFe/Cr] Multilayers (NiFe/Cr 다층박막의 층수와 자기이방성에 따른 자기저항특성)

  • 황도근;이상석;박창만;이기암
    • Journal of the Korean Magnetics Society
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    • v.5 no.3
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    • pp.210-215
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    • 1995
  • $Glass\Cr_{40\AA}\{[Cr_{10\AA}\NiFe_{50\AA}]}_N$ multilayers (number of layer N = 1, 2, 3, 4, 5, 6, 10) were made by dc magnetron sputtering under magnetic anisotropy of 200 G. Magnetoresistance curve MR(xx), MR(xy) were measured for the parallel and perpendicular current direction to external magnetic field. MR(xx) curves for the number of layer N=1, 5, 10 were almost became about zero percent, however the curves of other numbers appeared the phenomena of "positive magnetoresistance" that the resistance increased to external magnetic field, and the irregular and reversed curves in the vicinity of H=0 Oe.

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